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Journal Cover The Knee
  [SJR: 1.236]   [H-I: 53]   [15 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0968-0160
   Published by Elsevier Homepage  [3043 journals]
  • Editorial
    • Authors: Michele Boffano
      Pages: 703 - 704
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Michele Boffano


      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.06.009
       
  • Biomechanical comparison of four coupled fixation systems for ACL
           reconstruction with bone socket or full-tunnel on the tibial side
    • Authors: Edoardo Monaco; Mattia Fabbri; Riccardo Maria Lanzetti; Andrea Del Duca; Luca Labianca; Andrea Ferretti
      Pages: 705 - 710
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Edoardo Monaco, Mattia Fabbri, Riccardo Maria Lanzetti, Andrea Del Duca, Luca Labianca, Andrea Ferretti
      Background To compare in an animal model the biomechanical properties of four coupled fixation devices currently used in ACL reconstruction. Three out of four devices used a full tibial tunnel with an interference screw, while the other one system used a tibial socket and an adjustable loop suspension device. The null hypothesis is that there are no biomechanical differences between all the techniques tested. Methods Thirty two femur–graft–tibia complexes were mounted on a tensile machine using bovine digital extensor tendons, porcine knees and four different fixation device combinations: – Group A: EndoButton CL and BioRCI – Group B: Rigidfix and Intrafix – Group C: Transfix and Deltascrew – Group D: TightRope-RT with the All-inside GraftLink technique. After a preconditioning with a tensile load of 90N for five minutes, 1000cycles between 0 and 150N were applied to the complex before the final pulled to failure. Stiffness and strength were evaluated at the final pullout, as was the displacement (slippage) at one, 100, 500, and 1000cycles. Results The multiple mean comparison led to a significant difference for the case of stiffness, with worse results in group C compared to group A (p=0.037). Conversely, no differences were found in UFL and slippage between all groups (p>0.05). Conclusion All the tested systems demonstrated in an animal model sufficient properties for a safe postoperative rehabilitation both for strength and for stiffness and slippage under cyclic loading.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.05.003
       
  • The influence of varus and valgus deviation on patellar kinematics in
           healthy knees: An exploratory cadaver study
    • Authors: Michael Worlicek; Benedikt Moser; Günther Maderbacher; Raphael Zentner; Florian Zeman; Joachim Grifka; Armin Keshmiri
      Pages: 711 - 717
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Michael Worlicek, Benedikt Moser, Günther Maderbacher, Raphael Zentner, Florian Zeman, Joachim Grifka, Armin Keshmiri
      Background Patellofemoral instability may lead to osteoarthritis, anterior knee pain, and patellar luxation. The purpose of this study was to conduct an exploratory investigation into the difference of patellar kinematics of healthy knees during extension/flexion cycles in neutral, varus and valgus alignment. Methods The three-dimensional patellar kinematics of 10 lower extremities of whole body cadavers were examined during passive motion, in neutral position, and under valgus and varus stress. Kinematics was recorded by means of an optical computer navigation system. Results The study samples did not significantly differ with regard to mediolateral patellar shift and epicondylar distance. Varus stress led to significantly higher external rotation than valgus stress (P =0.04) and to a significantly higher lateral patellar tilt than neutral position (P =0.016) and valgus stress (P =0.016). No difference was found between valgus stress and neutral position. Conclusion Analysis of tibiofemoral alignment alone is insufficient for predicting patellar kinematics.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.009
       
  • A novel physiological testing device to study knee biomechanics in vitro
    • Authors: Fabian van de Bunt; Kaj S. Emanuel; Thomas Wijffels; Peter N. Kooren; Idsart Kingma; Theodoor H. Smit
      Pages: 718 - 725
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Fabian van de Bunt, Kaj S. Emanuel, Thomas Wijffels, Peter N. Kooren, Idsart Kingma, Theodoor H. Smit
      Background To properly study knee kinetics, kinematics and the effects of injury and surgical treatment in vitro, the knee should be constrained as little as possible, while imposing physiological loads. A novel dynamic biomechanical knee system (BKS) is presented here. The aim of this study was to test the feasibility and reproducibility of the system and demonstrate its features with an Anterior Cruciate Ligament (ACL) lesion model. Methods Six goat knees were used in the current study. Flexion and extension simulating gait was imposed by a servo-motor, while normal joint load was applied by two artificial muscles. Intra-class correlation coefficients (ICCs) were assessed for inter-test measures, while paired t-tests were performed for comparison between intact knees and knees with ACL-lesion. Results The ICC's for inter-test measures based on all six goat knees were excellent: varus/valgus: ICC=0.93; rotation: ICC=0.94 (all p<0.01), and translation in frontal (x)-, side (y)- and upward (z)-direction (ICC=0.90, 0.88 & 0.94) (all p<0.01). A significant increase in joint center movement was found in knees after creating an ACL-lesion (p=0.018): translation increased more than two-fold in frontal (p=0.016), side (p=0.004) and upward (p=0.018) direction. Conclusions Five degrees of motion were reproducibly assessed in the intact joint, suggesting that the goat knee may find its natural pathway when loaded in the BKS. The novel five-degrees-of-freedom knee system allows a detailed study of the effect of a diversity of defects and surgical treatments on knee biomechanics under physiological loading conditions.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.006
       
  • Biomechanical performance of a collagen meniscus implant with regard to
           suture material and irrigation fluid
    • Authors: Clemens Gwinner; Philipp von Roth; Sebastian Schmidt; Jan-Erik Ode; Dag Wulsten; Arnd Hoburg
      Pages: 726 - 732
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Clemens Gwinner, Philipp von Roth, Sebastian Schmidt, Jan-Erik Ode, Dag Wulsten, Arnd Hoburg
      Background The role of meniscus scaffolds remains controversial as failure rates remain high. The aim of this study was to evaluate the pullout strength of different suture materials used for fixation of the Collagen Meniscus Implant (CMI) regarding different suture materials, and type or temperature of irrigation fluid. Methods One-hundred and twelve specimens were utilized with horizontal sutures and mounted to a dedicated test device. Loads were applied perpendicular to the CMI, until failure. Two differing suture materials – polydioxanone (PDS) and non-absorbable, braided polyester sutures (NABP) – were evaluated. Additionally, two common irrigation fluids – lactated Ringer's and electrolyte-free, hypotonic Mannitol–Sorbitol solution – were evaluated. Specimens were further evaluated according to different temperatures of the irrigation fluid. Half of the constructs were tested at room temperature (20°C) and half were evaluated at near-core body temperature (37°C). Results PDS sutures showed a significantly higher load-to-failure compared to NABP sutures (P=0.0008). Regarding the type of irrigation fluid, the electrolyte-free Mannitol–Sorbitol solution showed a significantly higher load-to-failure compared to the overall Ringer group (P b 0.0001). This was equivalent for both the PDS (P=0.015) and for the NABP sutures (P b 0.0001). The temperature of the irrigation fluid did not significantly influence load-to-failure. Conclusions PDS sutures and electrolyte-free Mannitol–Sorbitol irrigation fluid provided the best biomechanical properties regarding load-to-failure testing. This study underlines the potential to improve construct stability for the CMI by alteration of the suture material and the type of irrigation fluid, which should be considered whenever scaffold fixation is conducted.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.003
       
  • The impact of joint angle and movement velocity on sex differences in the
           functional hamstring/quadriceps ratio
    • Authors: Mark De Ste Croix; Youssif O. ElNagar; John Iga; Francisco Ayala; David James
      Pages: 745 - 750
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Mark De Ste Croix, Youssif O. ElNagar, John Iga, Francisco Ayala, David James
      Background Females are two to eight times more likely to suffer a non-contact injury compared with males thus the purpose of this study was to explore the influence of joint angle and movement velocity on sex differences in the functional hamstring to quadriceps ratio (H/QFUNC). Methods Isokinetic concentric and eccentric torque were determined in 110 participants (55 males and 55 females) through a 90° range of movement at 60, 120, and 240°/s. Testing was performed with the hip flexed at 10°. The H/QFUNC was determined at three specific joint angles (15, 30 and 45° flexion) and where peak torque occurred for concentric knee extension. Results A significant interaction effect (P<0.01) for sex and joint angle was observed with women demonstrating a lower H/QFUNC than males, especially at more extended knee positions. A significant sex by velocity interaction (P<0.01) indicated a lower H/QFUNC in women as velocity increased. Significant main effects (P<0.01) indicated that irrespective of sex the H/QFUNC increased as the knee extends and velocity increases. Conclusion Given the reduced H/QFUNC in females compared to males at more extended knee positions and faster velocities, this may contribute to the observed sex bias in reported injury rates.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.03.012
       
  • The influence of polyethylene bearing thickness on the tibiofemoral
           kinematics of a bicruciate retaining total knee arthroplasty
    • Authors: Geert Peersman; Josh Slane; Margo Dirckx; Arne Vandevyver; Philipp Dworschak; Thomas J. Heyse; Lennart Scheys
      Pages: 751 - 760
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Geert Peersman, Josh Slane, Margo Dirckx, Arne Vandevyver, Philipp Dworschak, Thomas J. Heyse, Lennart Scheys
      Background The recently reintroduced bicruciate retaining Total Knee Arthroplasty (BCR TKA) is an effort to reproduce kinematics closer to the native knee. However, there is no data on appropriate balancing with this implant. Balancing is crucial and challenging as medial and lateral polyethylene (PE) inlays are modular, which allows for placement of different thicknesses in the medial and lateral compartments. This study aimed at providing a detailed kinematic view on balancing BCR TKA. Methods Seven fresh frozen cadaver legs were mounted in a kinematic rig that applied squatting under application of physiologic quadriceps and hamstring forces. Additionally, specimen laxity was assessed using Lachman tests and varus/valgus stress tests. Following testing on the native knee, a BCR TKA was implanted in each specimen and all trials were repeated. Using one millimeter increments, five inlay thicknesses were tested to simulate optimal balancing, symmetric under-, and overstuffing, valgus constellation, and varus constellation. Results Overall, knee kinematics following BCR TKA seem to be very close to the native knee. The changes as introduced to tibiofemoral kinematics through over- or understuffing the polyethylene inserts are affecting the system only to a minor degree and generally lack statistical significance. Reproduction of the tibial varus via PE-Inlays did not lead to kinematics much closer to the native knee. Conclusions The changes introduced to tibiofemoral kinematics by removal of the conforming meniscus and cartilage and replacement with a flat PE insert and femoral component are of more impact than different inlay sizes and their combinations for a BCR TKA.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.03.010
       
  • Single-limb landing biomechanics are altered and patellar tendinopathy
           related pain is reduced with acute infrapatellar strap application
    • Authors: Adam B. Rosen; Jupil Ko; Cathleen N. Brown
      Pages: 761 - 767
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Adam B. Rosen, Jupil Ko, Cathleen N. Brown
      Background Patellar tendinopathy, a common condition of the knee, is often treated with patellar tendon straps to control pain during dynamic activity. Little is known regarding their effect on pain, landing kinematics and kinetics with their application. The purpose of this study was to determine if patellar tendon straps influenced pain, kinematics at landing and ground reaction forces in individuals with patellar tendinopathy versus healthy controls. Methods Thirty participants with patellar tendinopathy and 30 controls participated. They completed single-limb landings with and without patellar tendon straps while pain, three-dimensional kinematics and vertical ground reaction forces were measured. A multivariate analysis of variance was completed to determine the differences in strapping condition and group for the dependent variables. Results Individuals with patellar tendinopathy demonstrated a significant decrease in pain (no strap=37.1±22.1mm (mean±SD), strap=28.0±18.5mm (mean±SD)). With the strap at landing all participants displayed less hip rotation (F =7.16, p =.01), knee adduction (F =10.20, p =.002), ankle inversion (F =4.60, p =.04), and peak vertical ground reaction force (F =7.30, p =.009). Conclusions Patellar tendon straps reduced pain in those with patellar tendinopathy. Additionally, with the strap, individuals landed in a more neutral alignment and decreased landing forces which could provide a benefit to those with patellar tendinopathy.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.03.003
       
  • Validating the forgotten joint score-12 in patients after ACL
           reconstruction
    • Authors: Henrik Behrend; Karlmeinrad Giesinger; Vilijam Zdravkovic; Johannes M. Giesinger
      Pages: 768 - 774
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Henrik Behrend, Karlmeinrad Giesinger, Vilijam Zdravkovic, Johannes M. Giesinger
      Background The forgotten joint score-12 (FJS-12), used to measure postoperative joint awareness, has been extensively validated to assess outcomes after arthroplasty, however the new score has never been validated in evaluating anterior cruciate ligament (ACL) reconstruction. The purpose of our study was to validate the FJS-12 versus the knee injury and osteoarthritis outcome score (KOOS) for patients who have undergone ACL reconstruction. Methods All patients who had undergone ACL reconstruction with the same arthroscopic surgical technique at our institution between 2011 and 2014 (medium-term follow-up group (M-FU)) or between 2000 and 2005 (long-term follow-up group (L-FU)) were considered for inclusion in the study. To analyze unidimensionality of the FJS-12, we calculated Cronbach's alpha, item-total correlations and conducted an exploratory principal component factor analysis. To assess convergent validity, we calculated Spearman correlation coefficients for the FJS-12 and its comparable scales. Results We analyzed 58 patients of the M-FU (mean follow-up 31.5 (SD13.4) months, range 12–54), and 58 patients of the L-FU (mean follow-up 139 (SD15.2) months, range 120–179). The FJS-12 showed high internal consistency (Cronbach's alpha=0.95). Ceiling effects were considerably lower for the FJS-12 (M-FU 12.1%, L-FU 15.5%) compared with the KOOS subscales (M-FU 5.2–37.9%; L-FU 13.8–55.2%) and WOMAC subscales (M-FU 37.9–62.1%; L-FU 44.8–60.3%). Conclusions The FJS-12 is a valid measurement tool to evaluate outcomes of ACL reconstruction. This study extends the possibilities of measuring joint awareness as a patient-reported outcome parameter from joint arthroplasty to ACL reconstruction.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.007
       
  • Static tensioning promotes hamstring tendons force relaxation more
           reliably than cycling tensioning
    • Authors: Sérgio Rocha Piedade; Inácio Maria Dal Fabbro; Martha Maria Mischan; Cezar Piedade; Nicola Maffulli
      Pages: 775 - 781
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Sérgio Rocha Piedade, Inácio Maria Dal Fabbro, Martha Maria Mischan, Cezar Piedade, Nicola Maffulli
      Background Graft elongation might be a major reason for increased anterior laxity after anterior cruciate ligament (ACL) reconstruction. This study analyzed the force relaxation values and their stabilization when single strands of the gracilis and semitendinosus tendons underwent cyclic and static tensioning at 2.5% strain level, and compared the efficiency of static and cyclic tensioning in promoting force relaxation. Methods Eighteen gracilis tendons and 18 semitendinosus tendons from nine male cadavers (mean age: 22.44years) were subjected to 10 in vitro cyclic loads at 2.5% strain level, or to a static load at 2.5% strain level. Results During cyclic loading, the reduction in force values tended to stabilize after the sixth cyclic load, while, in the case of static loading, this stabilization occurred by the second minute. Comparing static and cyclic loading, the gracilis tendon had similar mechanical responses in both conditions, while the semitendinosus tendon showed greater force relaxation in static compared with cyclic loading. Conclusions Considering that the semitendinosus tendon is the main component of the hamstring graft, its biomechanical response to loading should guide the tensioning protocol. Therefore, static tensioning seems more effective for promoting force relaxation of the semitendinosus tendon than cyclic tensioning. The gracilis tendon showed a similar mechanical response to either tensioning protocols.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.017
       
  • Range of motion and complications following primary repair versus
           reconstruction of the anterior cruciate ligament
    • Authors: Jelle P. van der List; Gregory S. DiFelice
      Pages: 798 - 807
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Jelle P. van der List, Gregory S. DiFelice
      Introduction Recently, there has been a resurgence of interest in primary anterior cruciate ligament (ACL) repair. The procedure is less invasive than ACL reconstruction, yet studies assessing early postoperative course are lacking. Goal therefore was to assess postoperative range of motion (ROM), complications and operative times following primary repair and compare this to the gold standard of reconstruction. Methods A retrospective study was performed for which 52 repair and 90 reconstruction patients could be included. Patients were examined at one week and one, three and six months. Rehabilitation protocol consisted of early ROM and was equal for both groups. Outcomes were compared using independent t-tests and chi-square tests, and reported in mean±standard deviation. Results Repair had more ROM than reconstruction patients at one week (89°±18 vs. 61°±21, p<0.01) and one month (125°±14 vs. 116°±18, p < 0.01) postoperatively. Fewer repair patients had 90° ROM at one week (23% vs. 84%, p<0.01), and more repair patients had full ROM at one month (57% vs. 30%, p<0.01). Treatment of meniscal lesions, but not chondral lesions, influenced ROM. Trends towards fewer complications (2% vs. 9%, p=0.19) and infections (0% vs. 6%, p=0.20) were noted following primary repair, and the procedure was significantly shorter. Conclusions: Following primary repair, patients had better ROM, and trends towards fewer complications than reconstruction. Primary repair is a safe, brief procedure with early ROM and low complication rates.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.007
       
  • Pigmented villonodular synovitis of the knee: A retrospective analysis of
           214 cases at a UK tertiary referral centre
    • Authors: K.H. Patel; P.D. Gikas; R.C. Pollock; R.W. Carrington; S.R. Cannon; J.A. Skinner; T.W. Briggs; W.J.S. Aston
      Pages: 808 - 815
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): K.H. Patel, P.D. Gikas, R.C. Pollock, R.W. Carrington, S.R. Cannon, J.A. Skinner, T.W. Briggs, W.J.S. Aston
      Aims Pigmented villonodular synovitis (PVNS) is a rare, locally aggressive and potentially recurrent synovial disease. We present the largest single-centre experience of knee PVNS. Our aim was to evaluate our tertiary hospital's experience in the management of knee PVNS. Patients and methods Retrospective data collection of consecutive cases of knee PVNS from 2002 to 2015. Results In total, 214 cases of knee PVNS were identified which represented 53.4% of all PVNS (12.1% were recurrent at presentation). 100 were localised PVNS (LPVNS), 114 diffuse PVNS (DPVNS) and two malignant PVNS. Knee PVNS was more likely to occur in females with a mean age of 39. Following surgery, 47.6% had recurrence with DPVNS as opposed to 8.6% with LPVNS. In LPVNS, there was no significant difference in recurrence between open and arthroscopic synovectomy (8.7% vs 9.1%, P >0.05). However, in DPVNS, there was a significantly higher risk of recurrence with arthroscopic compared to open synovectomy (83.3% vs 44.8%, RR =1.86 95% CI 1.32–2.62, P =0.0004). Conclusion PVNS can be difficult to treat. We found no difference in local recurrence rates between open and arthroscopic treatment of LPVNS but significantly increased rates of recurrence for DPVNS following arthroscopic treatment. We would therefore recommend open synovectomy for DPVNS.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.03.011
       
  • No associations between self-reported knee joint instability and
           radiographic features in knee osteoarthritis patients prior to Total Knee
           Arthroplasty: A cross-sectional analysis of the Longitudinal Leiden
           Orthopaedics Outcomes of Osteo-Arthritis study (LOAS) data
    • Authors: Claudia S. Leichtenberg; Jorit J.L. Meesters; Herman M. Kroon; Suzan H.M. Verdegaal; Claire Tilbury; Joost Dekker; Rob G.H.H. Nelissen; Thea P.M. Vliet Vlieland; Martin van der Esch
      Pages: 816 - 823
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Claudia S. Leichtenberg, Jorit J.L. Meesters, Herman M. Kroon, Suzan H.M. Verdegaal, Claire Tilbury, Joost Dekker, Rob G.H.H. Nelissen, Thea P.M. Vliet Vlieland, Martin van der Esch
      Background To describe the prevalence of self-reported knee joint instability in patients with pre-surgery knee osteoarthritis (OA) and to explore the associations between self-reported knee joint instability and radiological features. Methods A cross-sectional study including patients scheduled for primary Total Knee Arthroplasty (TKA). Self-reported knee instability was examined by questionnaire. Radiological features consisted of osteophyte formation and joint space narrowing (JSN), both scored on a 0 to three scale. Scores >1 are defined as substantial JSN or osteophyte formation. Regression analyses were provided to identify associations of radiological features with self-reported knee joint instability. Results Two hundred and sixty-five patients (mean age 69years and 170 females) were included. Knee instability was reported by 192 patients (72%). Substantial osteophyte formation was present in 78 patients (41%) reporting and 33 patients (46%) not reporting knee joint instability. Substantial JSN was present in 137 (71%) and 53 patients (73%), respectively. Self-reported knee instability was not associated with JSN (relative to score 0, odds ratios (95% CI) of score 1, 2 and 3 were 0.87 (0.30–2.54), 0.98 (0.38–2.52), 0.68 (0.25–1.86), respectively) or osteophyte formation (relative to score 0, odds ratios (95% CI) of score 1, 2 and 3 were 0.77 (0.36–1.64), 0.69 (0.23–1.45), 0.89 (0.16–4.93), respectively). Stratified analysis for pain, age and BMI showed no associations between self-reported knee joint instability and radiological features. Conclusion Self-reported knee joint instability is not associated with JSN or osteophyte formation.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.001
       
  • A regional registry study of 216 patients investigating if patient
           satisfaction after total knee arthroplasty changes over a time period of
           five to 20years
    • Authors: Odei Shannak; Jeya Palan; Colin Esler
      Pages: 824 - 828
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Odei Shannak, Jeya Palan, Colin Esler
      Aims To determine the temporal changes in patient dissatisfaction following primary knee arthroplasty surgery (TKA). Patients and methods Three hundred and ninety patients that had previously indicated they were either dissatisfied or unsure with their TKA at one-year post-surgery in our region were mailed a simple questionnaire in addition to the Oxford Knee Score and EQ-5D. Results A 55% response rate was achieved. The mean follow-up time period was 9.1years. Of the 120 patients who were initially dissatisfied, 46.7% remained so. Of the 96 patients who were initially unsure, 20.8% remained so, 21.9% and 57.3% became dissatisfied and satisfied, respectively. The primary reason for continued dissatisfaction was persistent pain. Of the 19.4% of patients who had revision surgery, 47.6% remained dissatisfied. 54.2% of patients stated that they would be happy to have a primary TKA again and 55.6% indicated that they would recommend one to a friend. Patients who had concurrent hip pain were six times more likely to remain unsure or dissatisfied over time (OR 6.7, p-value 0.0000). Patients who had back pain or contralateral knee pain were two or three times as likely to remain unsure or dissatisfied. Conclusion In time half of the patients who stated that they were not satisfied with their arthroplasty, at one year, go on to be satisfied with their knee.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.03.005
       
  • Long-term outcome of knee arthroplasty in the setting of pigmented
           villonodular synovitis
    • Authors: Matthew T. Houdek; Maurizio Scorianz; Cody C. Wyles; Robert T. Trousdale; Franklin H. Sim; Michael J. Taunton
      Pages: 851 - 855
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Matthew T. Houdek, Maurizio Scorianz, Cody C. Wyles, Robert T. Trousdale, Franklin H. Sim, Michael J. Taunton
      Background Pigmented villonodular synovitis (PVNS) is a rare, benign proliferation of the synovium, commonly affecting the knee. Arthroplasty can successfully manage arthrosis in this population; however, outcome data is limited. The purpose of this study was to investigate the oncologic and functional outcome of patients undergoing total knee arthroplasty (TKA) in the setting of PVNS. Methods 48 patients were identified at our institution with histologically confirmed PVNS that subsequently received TKA. The cohort consisted of 28 females and 20 males with a mean age and body mass index of 61years and 29.2kg/m2. 37patients had “active” disease, defined as diffuse in 40 patients and focal in eight. Mean follow-up was 14years. Results The 10-year disease free-survival was 88%. Recurrence occurred in 6 patients and was treated with synovectomy and revision arthroplasty (n=4), local excision (n=1) and transfemoral amputation (n=1). 25 patients sustained at least 1 complication, most commonly decreased knee range of motion. Complications resulted in revision TKA in 10 patients (21%). There was no difference (P=0.74) between mean pre- and postoperative ROM; however, there was a significant reduction in the number of patients with a flexion contracture >15° (P=0.03). The mean Knee Society score and functional score significantly improved following surgery (P <0.001). Conclusions This study indicates arthroplasty in the setting of PVNS improves patient function and reduces the presence of flexion contractures. Patients with a history of PVNS should be cautioned when undergoing arthroplasty on the elevated risk of subsequent procedures. Level of evidence Level III.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.019
       
  • Multifactorial analysis of dissatisfaction after primary total knee
           replacement
    • Authors: Kunal Dhurve; Corey Scholes; Sherif El-Tawil; Aseem Shaikh; Lai Kah Weng; Kumbelin Levin; Brett Fritsch; David Parker; Myles Coolican
      Pages: 856 - 862
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Kunal Dhurve, Corey Scholes, Sherif El-Tawil, Aseem Shaikh, Lai Kah Weng, Kumbelin Levin, Brett Fritsch, David Parker, Myles Coolican
      Background The aims of this study were to identify the prevalence and causes of dissatisfaction in a cohort of private practice patients, and to compare the psychological characteristics of dissatisfied patients to matched, satisfied controls. Methods Unilateral TKR patients were evaluated to identify those dissatisfied with their TKR. Dissatisfied and satisfied patients were matched in terms of age, gender, follow-up duration and body mass index (BMI). Psychological evaluation was performed using the Pain Catastrophizing Scale (PCS), Depression, Anxiety and Stress Scale (DASS) and the Multidimensional Health Locus of Control (MHLC) scale. The preoperative grade of osteoarthritis, prevalence of comorbidities, and postoperative functional outcomes, were also compared. Results A cohort comprised 301 patients (response rate 71%), with 24 patients (eight percent) dissatisfied at a mean follow-up of 37months (range eight to 74months). Persistent pain was the most common reason for dissatisfaction (n=10). Dissatisfied patients reported a significantly higher mean PCS score (P=0.03), higher depression component of the DASS (P=0.02) and lower internal locus of control (P=0.02). The dissatisfied group exhibited reduced improvement (P<0.05) in the Oxford Knee Score (OKS) and range of motion (ROM), as well as a lower preoperative grade of osteoarthritis compared to satisfied patients. Conclusions Dissatisfied patients exhibit an altered psychological profile to matched satisfied controls. In addition, they have lesser improvements in the OKS and ROM. Thus, both physical as well as psychological factors contribute to dissatisfaction. Identification of these factors may help in planning focused interventions to address dissatisfaction.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.005
       
  • Rapidly growing non-tuberculous mycobacteria infection of prosthetic knee
           joints: A report of two cases
    • Authors: Manyoung Kim; Chul-Won Ha; Jae Won Jang; Yong-Beom Park
      Pages: 869 - 875
      Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4
      Author(s): Manyoung Kim, Chul-Won Ha, Jae Won Jang, Yong-Beom Park
      Non-tuberculous mycobacteria (NTM) cause prosthetic knee joint infections in rare cases. Infections with rapidly growing non-tuberculous mycobacteria (RGNTM) are difficult to treat due to their aggressive clinical behavior and resistance to antibiotics. Infections of a prosthetic knee joint by RGNTM have rarely been reported. A standard of treatment has not yet been established because of the rarity of the condition. In previous reports, diagnoses of RGNTM infections in prosthetic knee joints took a long time to reach because the condition was not suspected, due to its rarity. In addition, it is difficult to identify RGNTM in the lab because special identification tests are needed. In previous reports, after treatment for RGNTM prosthetic infections, knee prostheses could not be re-implanted in all cases but one, resulting in arthrodesis or resection arthroplasty; this was most likely due to the aggressiveness of these organisms. In the present report, two cases of prosthetic knee joint infection caused by RGNTM (Mycobacterium abscessus) are described that were successfully treated, and in which prosthetic joints were finally reimplanted in two-stage revision surgery.

      PubDate: 2017-07-18T21:43:53Z
      DOI: 10.1016/j.knee.2017.04.015
       
  • Role of tear location on outcomes of open primary repair of the anterior
           cruciate ligament: A systematic review of historical studies
    • Authors: Jelle P. van der List; Gregory S. DiFelice
      Abstract: Publication date: Available online 10 August 2017
      Source:The Knee
      Author(s): Jelle P. van der List, Gregory S. DiFelice
      Background The general opinion is that outcomes of open primary repair of the anterior cruciate ligament (ACL) in the historical literature were disappointing. Since good outcomes of primary repair of proximal tears have recently been reported, we aimed to assess the role of tear location on open primary repair outcomes in the historical literature. Methods All studies reporting outcomes of open primary ACL repair published between the inception of PubMed, Embase and Cochrane and 2000 were identified. Studies were included if tear location was reported. Outcome scores, return to sports, stability examinations, failures and patient satisfaction were collected and reviewed in the total study cohort and in a subgroup of studies treating only proximal tears. Spearman correlation analysis was performed between the percentage of proximal tears in the studies and all outcomes. Results Twenty-nine studies were included reporting outcomes of open primary in 1457 patients of which 72% had proximal and 23% midsubstance tears. Mean age was 30years, 65% were males, and mean follow-up was 3.6years. Good outcomes were noted in the total cohort, and excellent outcomes were noted following repair of proximal tears. Positive correlation was found between the percentage proximal tears in the studies and percentage satisfied patients (p=0.010). Conclusion Tear location seems to have played a role on the outcomes of open primary ACL repair. Outcomes of open primary repair in patients with proximal tears were excellent, which confirms there may be a potential role for primary repair as treatment for proximal ACL tears.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.009
       
  • Association between body weight and proximal tibial bone mineral density
           after bilateral total knee arthroplasty
    • Authors: Yoshinori Ishii; Hideo Noguchi; Junko Sato; Hana Ishii; Koji Todoroki; Shin-ichi Toyabe
      Abstract: Publication date: Available online 10 August 2017
      Source:The Knee
      Author(s): Yoshinori Ishii, Hideo Noguchi, Junko Sato, Hana Ishii, Koji Todoroki, Shin-ichi Toyabe
      Background Proximal tibial bone mineral density (BMD) has been studied for its potential impact on subsidence and loosening of the tibial component after total knee arthroplasty (TKA). However, no known studies of proximal tibial BMD after TKA have evaluated the effect of major impact factors such as body weight (BW), muscle strength, and level of activity. We aim to determine whether factors such as level of activity, quadriceps strength, BW, gender, age, and prosthetic design affect proximal tibial BMD over the mid- to long-term following TKA. Methods We evaluated 36 patients (72 knees) who were undergoing bilateral TKA performed by a single surgeon. Median follow up time was 115months (range, 60–211months) for a minimum of five years. We measured BMD in the proximal tibia and used a hand-held dynamometer to measure quadriceps isometric strength, recording the maximum value of three measurements for each patient. Results Univariate analyses using Spearman's correlation coefficient for continuous variables revealed a weak negative correlation between age and BMD (r =−0.316, P =0.007) and a moderate positive correlation between BW and BMD (r =0.430, P <0.001). However, no significant correlations were found between the other factors above and BMD for continuous and discrete variables. Based on multivariate analyses, only BW had a significant effect on BMD (β=0.342, P =0.003). Conclusions BW is the most impact factor on the proximal tibial BMD after mid- to long-term follow up TKA. Therefore, the management of BW may contribute to prevention of decline of tibial BMD for TKA patients owing to aging.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.012
       
  • Bone tunnel change develops within two weeks of double-bundle anterior
           cruciate ligament reconstruction using hamstring autograft: A comparison
           of different postoperative immobilization periods using computed
           tomography
    • Authors: Ryo Shimizu; Nobuo Adachi; Minoru Ishifuro; Atsuo Nakamae; Masakazu Ishikawa; Masataka Deie; Mitsuo Ochi
      Abstract: Publication date: Available online 9 August 2017
      Source:The Knee
      Author(s): Ryo Shimizu, Nobuo Adachi, Minoru Ishifuro, Atsuo Nakamae, Masakazu Ishikawa, Masataka Deie, Mitsuo Ochi
      Background The purpose of this study was to evaluate bone tunnel changes following anterior cruciate ligament (ACL) reconstruction during the early postoperative period using computed tomography (CT), and to understand the impact of postoperative immobilization on these changes. Methods Twenty patients who underwent double-bundle ACL reconstruction using hamstring tendon autografts were included. We subcategorized patients into two groups: patients who underwent isolated ACL reconstruction and had three days of knee immobilization (Group A, n=10); and patients with concomitant meniscus injuries who underwent ACL reconstruction and meniscus repair simultaneously (Group B, n=10) had their knees immobilized for two weeks after surgery. Bone tunnel enlargement was evaluated using CT imaging at one to three days, two weeks, one month, three months and six months after surgery. The cross-sectional area of the femoral and tibial tunnels was measured, and enlargement rate was calculated. The tunnel center location at two weeks after surgery was also evaluated. Results The mean cross-sectional area adjacent to the joint space of the femoral and tibial tunnels significantly increased immediately after surgery, especially in the first month (P <0.01). However, after one to six months they were not increased (P >0.01). There was no significant difference in tunnel enlargement rate between group A and B. Tunnel center location changed even in the first two weeks. Conclusions Bone tunnel enlargement following double-bundle ACL reconstruction occurred at an earlier time point after surgery than anticipated. Postoperative immobilization could not prevent bone tunnel enlargement, but might prevent tunnel migration.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.013
       
  • Success rates, characteristics, and costs of articulating antibiotic
           spacers for total knee periprosthetic joint infection
    • Authors: Scott R. Nodzo; Keely K. Boyle; Sara Spiro; Allina A. Nocon; Andy O. Miller; Geoffrey H. Westrich
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Scott R. Nodzo, Keely K. Boyle, Sara Spiro, Allina A. Nocon, Andy O. Miller, Geoffrey H. Westrich
      Background The optimal type, characteristics, and success rates of articulating antibiotic spacers used during total knee arthroplasty (TKA) periprosthetic joint infection (PJI) have not been well defined in a single series. We sought to (1) determine the success rate for three unique spacer constructs and (2) evaluate any microbiological, surgical, or patient characteristics that would influence the success rate. Methods We retrospectively reviewed patients who underwent a two-stage exchange for a TKA PJI with a prefabricated spacer (PREFAB), home-made mold (MOLD), or autoclaved femoral component (AUTOCL). Patient demographics, microbiology data, amount of antibiotic in each spacer construct, postoperative course, and infection cure outcomes were evaluated. Results The success rate for being infection free at final follow-up without the need for further reoperation for infection was 82.7% in the PREFAB group, 88.4% in the MOLD group, and 79.4% in the AUTOCL group (p=0.54). There was no clear statistical link between raw quantities of vancomycin and aminoglycoside in the spacer and a successful outcome. The surgeon's own intraoperatively created mold group had the lowest construct cost at a mean $1341.00±889.10 (p<0.0001) per construct, while the commercial cement molds had the highest mean cost at $5439.00±657.80 (p<0.0001). Conclusions There was no statistically significant difference in the success rates between the antibiotic spacer types. The surgeon's own intraoperative mold had the least overall associated cost.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.016
       
  • Factors affecting articular cartilage repair after open-wedge high tibial
           osteotomy
    • Authors: Chang-Wan Kim; Seung-Suk Seo; Chang-Rack Lee; Heui-Chul Gwak; Jung-Han Kim; Sun-Gyu Jung
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Chang-Wan Kim, Seung-Suk Seo, Chang-Rack Lee, Heui-Chul Gwak, Jung-Han Kim, Sun-Gyu Jung
      Background To evaluate the factors that affect articular cartilage repair after open-wedge high tibial osteotomy (OWHTO) and the relationship between regeneration of articular cartilage repair and clinical outcomes. Methods Among the cases of OWHTO that were performed from March 2005 to February 2012, the patients who followed up for >2years and received a second-look arthroscopy were retrospectively reviewed. For clinical evaluation, the Knee Society scores and Western Ontario and McMaster Universities Osteoarthritis Index score were measured. For radiologic evaluation, the Kellgren–Lawrence scale, mechanical femorotibial angle, and joint line obliquity were used. In the initial and second-look arthroscopy, the status of the articular cartilage of the medial compartment was evaluated. Results A total of 62 knees (61 patients) were included in this study. Articular cartilage repair was observed in 18 knees (29.0%). In multiple logistic regression analysis, patients with Kellgren–Lawrence Grade 4 (OR 0.076; 95% CI 0.007–0.822; P =0.034), the existence of a bipolar lesion (OR 0.108; 95% CI 0.016–0.724; P =0.022), or joint line obliquity >5° (OR 0.109; 95% CI 0.013–0.936; P =0.043) had significantly lower odds of articular cartilage repair compared to the corresponding counter group. In a comparison of clinical outcomes between a group that had articular cartilage repair and a group without repair, no significant difference was observed (P >0.05). Conclusions Severe arthrosis, existence of a bipolar lesion, and marked postoperative joint line obliquity had a negative impact on articular cartilage repair after OWHTO. However, articular cartilage repair showed unknown clinical significance.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.001
       
  • Can kinematic tibial templates assist the surgeon locating the flexion and
           extension plane of the knee'
    • Authors: Nikolaos K. Paschos; Stephen M. Howell; J. Micheal Johnson; Mohamed R. Mahfouz
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Nikolaos K. Paschos, Stephen M. Howell, J. Micheal Johnson, Mohamed R. Mahfouz
      Purpose We performed virtual feasibility and in-vivo validation studies to test whether the use of a kinematic tibial template (KTT) assists the surgeon in accurately locating the orientation of the F-E of the knee with low bias and high precision. Methods With use of 166 3-dimensional bone models of normal knees, we designed seven KTTs that located the orientation of the F-E plane of the knee when best-fit within the cortical edge of the tibial resection. The virtual feasibility study asked 11 evaluators with different levels of surgical experience to use software and select, orient, and best-fit the KTT within the tibial resection of each bone model. The in-vivo validation study analyzed tibial component rotation on postoperative CT scans of 118 consecutive patients after one surgeon set the I-E rotation of the tibial component with a KTT when performing kinematically-aligned TKA. Bias and precision were computed as the mean and standard deviation of the differences between the A-P axis of the KTT and the F-E plane of the knee. Results For the virtual feasibility study, the bias was 0.7° external and the precision was ±4.6° for 1826 KTT fittings, which were not affected by the level of surgical experience. For the in-vivo validation study, the bias was 0.1° external and the precision was ±3.9°. Conclusions The virtual feasibility and in-vivo validation studies suggest a KTT can assist the surgeon in accurately setting the I-E rotation of the tibial component parallel to the F-E plane of the knee when performing kinematically-aligned TKA.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.008
       
  • The anterolateral ligament: Anatomic implications for its reconstruction
    • Authors: Neri Thomas; Palpacuer Fabien; Testa Rodolphe; Bergandi Florian; Boyer Bertrand; Farizon Frederic; Philippot Remi
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Neri Thomas, Palpacuer Fabien, Testa Rodolphe, Bergandi Florian, Boyer Bertrand, Farizon Frederic, Philippot Remi
      Background The purpose of this study was to define the best anatomic parameters with which to perform an accurate anterolateral ligament (ALL) reconstruction. These parameters were anatomical insertions, allowing favorable isometry, length variation during flexion, and anthropometric predictors of ALL lengths. Methods A total of 84 fresh-frozen cadaver knees were dissected to analyze the ALL, focusing on its femoral insertion. The ALL length was measured in different degrees of flexion (extension, 30°, 60°, and 90° of flexion) and rotation (neutral, internal or external rotation). The ALL width and thickness were measured. A correlation between ALL length, the general knee size and individual characteristics was investigated. Results The ALL was present in 80 specimens (95%). The femoral footprint was always posterior (5.52±0.93 mm, range 3.83–6.94) and slightly proximal (1.51±0.75mm, range 0.63–2.37) to the lateral femoral epicondyle. The mean ALL length increased with internal rotation and decreased with external rotation (P<0.05). The maximum ALL length was found at 30° of flexion, and the minimum at 90°. There was a significant correlation between the ALL length and height, sex, and proximal femur dimensions. Conclusion In order to get an anatomical reconstruction with favorable isometry, it is recommended that the ALL femoral graft is implanted posterior and slightly proximal to the epicondyle. It is also suggested that the tension be adjusted by fixing the graft between 0 and 30° of flexion, being tighter near extension. This will allow good rotational stability without implying any stiffness.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.001
       
  • Up to seven years' follow-up of short cemented stems in complex primary
           total knee arthroplasty: A prospective study
    • Authors: Mathieu Angers-Goulet; Martin Bédard
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Mathieu Angers-Goulet, Martin Bédard
      Background Although primary total knee arthroplasty (TKA) shows good clinical, functional and radiological results, it can be complicated by certain conditions or pathologies. The main objective of this study was to evaluate the global performance of short cemented metaphyseal stem components in patients undergoing complex primary TKA. Methods This is a single-surgeon prospective case series of 91 patients who underwent complex primary TKA requiring short stem fixation between January 2009 and October 2014. Knee Society Scores, physical examinations, and radiological assessments were performed pre- and postoperatively at six weeks, three months, six months, 12months, and annually thereafter. Results There were 40 females (46 TKAs) and 40 males (45 TKAs) in the study cohort. The left knee accounted for 52.7% of the surgeries. The average body-mass index (BMI) was 31.8kg/m2. Knee Society Scores obtained at the latest follow-up showed 96.4% and 95.5% good-to-excellent results respectively for the Knee and Function sub-scores. Radiological assessment showed that all Knee Society roentgenographic scores were below 10, without any evidence of impending or possible failure. Only one revision was required in this cohort for a patient suffering a deep chronic infection. At seven years, the Kaplan–Meier survivorship analysis revealed a 100% survivorship for aseptic loosening and a 98.9% survivorship for infection and revision of the components for any reason. Conclusion This study demonstrated that TKA with short cemented stems resulted in good functional, clinical, and radiological outcomes for up to seven years for patients requiring complex TKA.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.010
       
  • Radiographic analysis of the lower limbs using the hip–calcaneus line in
           healthy individuals and in patients with varus knee osteoarthritis
    • Authors: Toshikazu Tanaka; Koji Takayama; Shingo Hashimoto; Noriyuki Kanzaki; Shinya Hayashi; Ryosuke Kuroda; Tomoyuki Matsumoto
      Abstract: Publication date: Available online 8 August 2017
      Source:The Knee
      Author(s): Toshikazu Tanaka, Koji Takayama, Shingo Hashimoto, Noriyuki Kanzaki, Shinya Hayashi, Ryosuke Kuroda, Tomoyuki Matsumoto
      Background Several recent reports define the line from the centre of the femoral head to the lowest point of the calcaneus. The purpose of this study was to comparatively examine the usefulness of the hip–calcaneus (HC) line and hip–ankle (HA) line for the evaluation of lower-limb alignment in healthy individuals and in patients with osteoarthritis (OA). Methods Participants included 34 healthy individuals (mean age, 26.4years) and 34 patients with OA (mean age, 74.2years). Frontal radiographs of the entire lower limb were taken in single- and double-leg stances. For each group, the hip–knee–ankle (HKA) and hip–knee–calcaneus (HKC) angles were assessed and compared within and between stances. In addition, the HA line and HC line were assessed as the passing line in the knee, and were similarly compared. Results Significant differences between the HKA and HKC angles, and between the HA line and HC line were observed in both groups during both stances. In addition, significant stance-related differences in the HKA and HKC angles, HA line, and HC line were found in the OA group, but not in the healthy group. Conclusions Our results suggest that the HC line of the lower limb differs from the HA line. Furthermore, single- and double-leg stances should also be considered, especially in patients with OA. These considerations may affect preoperative planning for high tibial osteotomies and TKA.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.015
       
  • Reply to Miller et al. (2016)
    • Authors: Hanatsu Nagano; Eri Sarashina; Ichiroh Tatsumi; W.A. Sparrow; Rezaul K. Begg
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Hanatsu Nagano, Eri Sarashina, Ichiroh Tatsumi, W.A. Sparrow, Rezaul K. Begg


      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.017
       
  • Using a non-invasive secure skin closure following total knee arthroplasty
           leads to fewer wound complications and no patient home care visits
           compared to surgical staples
    • Authors: Alberto V. Carli; Sara Spiro; Brian T. Barlow; Steven B. Haas
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Alberto V. Carli, Sara Spiro, Brian T. Barlow, Steven B. Haas
      Background Superficial wound complications occur in up to 10% of total knee arthroplasty (TKA) procedures and have been associated with periprosthetic joint infection. The ideal material for TKA closure should offer: 1) fast intraoperative application, 2) minimal wound complications and 3) removable by patients without assistance. We evaluated a novel, non-invasive, removable skin closure system for TKA to determine its effect on wound complications. Methods We prospectively evaluated 221 consecutive TKA patients who received skin closure using a non-invasive zipper-like system (‘Zip’; Zip 16 Surgical Skin Closure System; Zipline Medical). All procedures were performed by a single surgeon using the mini-midvastus approach. Patients received two weeks of rivaroxaban postoperatively. Demographics, comorbidities, in-hospital complications and six-week wound evaluation were recorded. Data was compared to a cohort of 1001 patients from the same surgeon who received staples for closure and coumadin for thromboprophylaxis. Results Zip patients had a significantly higher BMI (p=0.001), incidence of diabetes (p=0.035) and smoking (p=0.005). Zip patients removed dressings themselves and did not report problems with dressing care. Rate of readmission for wound-related complications was significantly lower in the Zip closure group (p=0.045). Overall readmission rates were similar between groups. Conclusions In our experience, the Zip 16 Surgical Skin Closure System is easy to apply, avoids home care and has produced fewer wound complications compared to staples. Results have been positive despite the study cohort having a higher number of diabetic patients and using an anticoagulant associated with a higher risk of wound complications.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.007
       
  • The diameter of single bundle, hamstring autograft does not significantly
           influence revision rate or clinical outcomes after anterior cruciate
           ligament reconstruction
    • Authors: Gregory C. Wernecke; Alex Constantinidis; Ian A. Harris; Bradley G. Seeto; Darren B. Chen; Samuel J. MacDessi
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Gregory C. Wernecke, Alex Constantinidis, Ian A. Harris, Bradley G. Seeto, Darren B. Chen, Samuel J. MacDessi
      Background Anterior cruciate ligament (ACL) graft failure is a complication of ACL reconstruction (ALCR). Smaller autograft diameter may be a contributing factor. Our aim was to determine if hamstring autograft diameter influences graft rupture and patient-reported outcome scores. Methods This study included 786 consecutive patients undergoing primary, single bundle, autograft hamstring ACLR. The primary outcome was revision ACLR surgery. Secondary outcomes were patient reported International Knee Documentation Committee (IKDC) score, Knee Injury & Osteoarthritis Outcome Score (KOOS) and Tegner Activity score. Multiple logistic regression and Fischer Exact tests were employed for statistical analysis. Results Increasing autograft diameter did not lead to a reduction in revision ACLR surgery (odds ratio [OR], 1.093; 95% confidence interval [CI], 0.612 to 1.954; P=0.76). Revision ACLR positively correlated with male gender (OR, 3.971; 95% CI 1.109 to 14.214; P=0.03) and negatively correlated with increasing age (OR, 0.919; 95% CI 0.882–0.958, P<0.0001). There was no association between graft rupture rate and dichotomized graft size. At latest follow-up, there was no correlation between graft diameter and IKDC (Pearson's adjusted R2 =0.058; P=0.75), Tegner Activity score (Pearson's adjusted R2 =0.244; P=0.53), or any component of the KOOS (Pearson's adjusted R2 range: 0.008 to 0.141; P-value range: 0.21 to 0.76). Conclusion Increased hamstring autograft diameter did not significantly reduce revision ACLR surgery or improve clinical outcomes. Other factors such as gender and age do influence the rate of revision ACL surgery. Study design Level IV, retrospective case series.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.011
       
  • Annual trends in knee arthroplasty and tibial osteotomy: Analysis of a
           national database in Japan
    • Authors: Manabu Kawata; Yusuke Sasabuchi; Hiroshi Inui; Shuji Taketomi; Hiroki Matsui; Kiyohide Fushimi; Hirotaka Chikuda; Hideo Yasunaga; Sakae Tanaka
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Manabu Kawata, Yusuke Sasabuchi, Hiroshi Inui, Shuji Taketomi, Hiroki Matsui, Kiyohide Fushimi, Hirotaka Chikuda, Hideo Yasunaga, Sakae Tanaka
      Background Various nationwide studies have reported differing annual trends in utilization of knee arthroplasty and tibial osteotomy. Using the Diagnosis Procedure Combination database in Japan, the present series examined annual trends and demographics in total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA) and tibial osteotomy. Methods All patients were identified who underwent TKA, UKA or tibial osteotomy for osteoarthritis, osteonecrosis or rheumatoid arthritis of the knee between July 2007 and March 2015. Results A total of 170,433 cases of TKA, 13,209 cases of UKA and 8760 cases of tibial osteotomy were identified. The proportion of patients undergoing UKA rose from 4.0% in 2007 to 8.1% in 2014 (P <0.001), and that of tibial osteotomy from 2.6% in 2007 to 5.5% in 2014 (P <0.001); the proportion undergoing TKA fell from 93.4% in 2007 to 86.3% in 2014 (P <0.001). Between 2007 and 2014 the proportions of patients with osteonecrosis who underwent UKA and tibial osteotomy increased from 34.7% and 11.6% to 38.6% and 16.2%, respectively (P =0.001 for UKA and P =0.004 for tibial osteotomy). The proportions of patients with osteonecrosis undergoing UKA or tibial osteotomy were significantly greater than those with other diagnoses (P <0.001 for both). Conclusions The popularity of UKA and tibial osteotomy in Japan increased during the period 2007–2014 at the expense of TKA. The proportions of UKA and tibial osteotomy in patients with osteonecrosis also increased, and were larger than those in patients with other causative diseases.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.005
       
  • Factors affecting knee laxity following anterior cruciate ligament
           reconstruction using a hamstring tendon
    • Authors: Shinya Yanagisawa; Masashi Kimura; Keiichi Hagiwara; Atsuko Ogoshi; Tomoyuki Nakagawa; Hiroyuki Shiozawa; Takashi Ohsawa
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Shinya Yanagisawa, Masashi Kimura, Keiichi Hagiwara, Atsuko Ogoshi, Tomoyuki Nakagawa, Hiroyuki Shiozawa, Takashi Ohsawa
      Background The aim of the present study was to investigate the correlation between the pre-operative and intraoperative factors that predict postoperative knee laxity following anterior cruciate ligament (ACL) reconstruction using a hamstring tendon. Methods The subjects included 108 patients (male, n=49; female, n=59) with ACL-deficient knees who had undergone double-bundle reconstruction. The median time between injury and surgery (TBIS) was 27.5weeks (range one to 504). The patients were divided into two groups according to the side-to-side difference (SSD) in anterior translation on a stress radiograph one year after undergoing the operation (Group A: SSD of <3mm and Group B: SSD of ≥3mm) and were compared regarding such factors as age at surgery, sex, body mass index, pivot shift test, TBIS, pre-operative laxity, concomitant ligament, meniscus, and articular cartilage injury. A logistic regression analysis was performed to identify the factors associated with knee laxity. Results The postoperative SSD values after one year were correlated with the TBIS (r =0.28; P <0.01). Eighty-one and 27 knees were classified into Groups A and B, respectively, based on the SSD at one year after surgery. The TBIS in Group B (60.2weeks) was significantly longer than that in Group A (16.6weeks; P <0.01). A logistic regression analysis showed that there was a significant association between the TBIS and postoperative knee laxity (P <0.01; odds ratio 1.013; 95% CI 1.002–1.023). Conclusion Increased knee laxity was associated with the time between injury and surgery.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.009
       
  • Smoking is associated with earlier time to revision of total knee
           arthroplasty
    • Authors: Chin Tat Lim; Stuart B. Goodman; James I. Huddleston; Alex H.S. Harris; Subhrojyoti Bhowmick; William J. Maloney; Derek F. Amanatullah
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Chin Tat Lim, Stuart B. Goodman, James I. Huddleston, Alex H.S. Harris, Subhrojyoti Bhowmick, William J. Maloney, Derek F. Amanatullah
      Background Smoking is associated with early postoperative complications, increased length of hospital stay, and an increased risk of revision after total knee arthroplasty (TKA). However, the effect of smoking on time to revision TKA is unknown. Methods A total of 619 primary TKAs referred to an academic tertiary center for revision TKA were retrospectively stratified according to the patient smoking status. Smoking status was then analyzed for associations with time to revision TKA using a Chi square test. The association was also analyzed according to the indication for revision TKA. Results Smokers (37/41, 90%) have an increased risk of earlier revision for any reason compared to non-smokers (274/357, 77%, p=0.031). Smokers (37/41, 90%) have an increased risk of earlier revision for any reason compared to ex-smokers (168/221, 76%, p=0.028). Subgroup analysis did not reveal a difference in indication for revision TKA (p>0.05). Conclusions Smokers are at increased risk of earlier revision TKA when compared to non-smokers and ex-smokers. The risk for ex-smokers was similar to that of non-smokers. Smoking appears to have an all-or-none effect on earlier revision TKA as patients who smoked more did not have higher risk of early revision TKA. These results highlight the need for clinicians to urge patients not to begin smoking and encourage smokers to quit smoking prior to primary TKA.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.014
       
  • Radiographic and computed tomographic evaluation of bone union after
           medial opening wedge high tibial osteotomy with filling gap
    • Authors: Hideo Kobayashi; Yasushi Akamatsu; Ken Kumagai; Yoshihiro Kusayama; Tomoyuki Saito
      Abstract: Publication date: Available online 7 August 2017
      Source:The Knee
      Author(s): Hideo Kobayashi, Yasushi Akamatsu, Ken Kumagai, Yoshihiro Kusayama, Tomoyuki Saito
      Background We evaluated bone union and remodelling in patients undergoing opening-wedge high tibial osteotomy (OWHTO) with bone gaps filled with beta-tricalcium phosphate. We examined the effectiveness of radiography and computed tomography (CT) for the evaluation of bone union and remodelling, and investigated whether lateral hinge fractures affected bone union. Methods Sixty-six cases underwent OWHTO with a combination of a TomoFix plate and a bone substitute. Bone union and remodelling were assessed using the rating system for OWHTO at three and six months, postoperatively. Results Radiographic evaluation showed that bone union of the lateral hinge was 85% and 100% at three and six months, respectively. Based on CT evaluation, bone union of the lateral hinge and the flange was achieved in all cases at six months, and the bone union of the posterior cortex reached Zone 3 in 83% at six months. Based on radiographic evaluation, bone remodelling phases of bone substitute had progressed in each zone in six months compared with three months. Radiographic and CT analyses identified a Takeuchi type I hinge fracture in fourteen (21.2%) and five (7.6%) knees at two weeks postoperatively, respectively. There were no differences in bone union with and without the lateral hinge fracture. Conclusions The use of CT enabled us to evaluate the bone union of the flange and the extent of the bone union of the posterior cortex. Plain radiographs are useful to evaluate bone union of the lateral hinge similar to CT analysis. The presence of a Takeuchi type I hinge fracture did not affect bone union.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.002
       
  • Commentary on “Modelling knee flexion effects on joint power absorption
           and adduction moment”
    • Authors: Ross H. Miller; Scott C.E. Brandon; W. Scott Selbie; Kevin J. Deluzio
      Abstract: Publication date: Available online 6 August 2017
      Source:The Knee
      Author(s): Ross H. Miller, Scott C.E. Brandon, W. Scott Selbie, Kevin J. Deluzio


      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.018
       
  • Influence of implant length and bone defect situation on primary stability
           after distal femoral replacement in vitro
    • Authors: Jan Nadorf; Simon B. Klein; Simone Gantz; Eike Jakubowitz; Jan Philippe Kretzer; Oliver E. Bischel
      Abstract: Publication date: Available online 6 August 2017
      Source:The Knee
      Author(s): Jan Nadorf, Simon B. Klein, Simone Gantz, Eike Jakubowitz, Jan Philippe Kretzer, Oliver E. Bischel
      Background Aseptic loosening is the major reason for failure of distal femoral replacement using current modular megaprostheses. Although the same stems are used for proximal and distal replacement, survival rates in clinical studies with distal reconstruction were lower within the same system compared to proximal reconstruction. We analyzed whether primary stability as presupposition for long-term fixation can be achieved with a current tapered stem design. Additionally, we hypothesized that stem length affects primary stability depending on bone defect situations. Methods A modular tumor system (Megasystem-C®, Link GmbH, Hamburg, Germany) with two different tapered stems (100 and 160mm) was implanted in eight Sawbones® in two consecutively created defect situations (10 and 20cm proximal to knee joint level). Primary rotational stability was investigated by measuring relative micromotions between implant and bone to identify the main fixation areas and to characterize the fixation pattern. Results The fixation differed between the two stem lengths and with respect to both defect situations; however in each case the main fixation area was located at or close to the femoral isthmus. Highest relative micromotions were measured with the 160-mm stem at the distal end within small bone defects and at the proximal end when defects were increased. Conclusions The analyzed design seemed to create sufficient primary stability along the main fixation areas of the implant. Based on these results and with respect to oncologic or potential revision situations, we suggest the use of the shorter stem to be more favorable in case of primary implant fixation.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.010
       
  • Outcome of prosthesis matched and unmatched patella components in primary
           and revision total knee replacement
    • Authors: Peter L. Lewis; Ai E. Gamboa; David G. Campbell; Michelle Lorimer
      Abstract: Publication date: Available online 6 August 2017
      Source:The Knee
      Author(s): Peter L. Lewis, Ai E. Gamboa, David G. Campbell, Michelle Lorimer
      Background Although knee replacements have specifically designed patella prostheses that correspond to the geometry of their femoral components, a patella prosthesis that is unmatched to the femoral component may occasionally be inserted. In revision total knee arthroplasty (TKA), an originally resurfaced patella may be left, but the femoral component revised to one that does not match the patella. Few studies have compared the outcome of matched and unmatched patella components in TKA. This study compared the primary or revision TKA outcome of procedures where patella components matched to their femoral counterparts were inserted, with procedures using patella and femoral components that were unmatched. Methods Data on all primary and revision TKA procedures without a patella component or a matched or an unmatched patella component were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Revision surgery was the outcome measure. Cumulative percent revised (CPR) were calculated and Hazard ratios with p values were used to test statistical significance. Results In primary TKA, there were higher rates of revision where unmatched patella components were used, regardless of implant design. There was no difference in the second revision rates of unmatched versus matched patella component groups. This was evident where delayed resurfacing was carried out, and where the patella prosthesis was left alone but the femoral component was changed. Conclusions All primary TKA procedures require a patella component corresponding to the femoral component if the patella is resurfaced. Conversely, revision knee arthroplasties are not affected by the use of dissimilar patella and femoral components.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.006
       
  • Patellofemoral arthroplasty conversion to total knee arthroplasty:
           Retrieval analysis and clinical correlation
    • Authors: Alexander B. Christ; Elexis Baral; Chelsea Koch; Beth E. Shubin Stein; Alejandro Gonzalez Della Valle; Sabrina M. Strickland
      Abstract: Publication date: Available online 6 August 2017
      Source:The Knee
      Author(s): Alexander B. Christ, Elexis Baral, Chelsea Koch, Beth E. Shubin Stein, Alejandro Gonzalez Della Valle, Sabrina M. Strickland
      Background Patellofemoral arthroplasty (PFA) can be a successful, bone-sparing treatment for isolated patellofemoral arthritis. However, progression of tibio-femoral arthritis or incorrect indications may predispose patients to early conversion to total knee arthroplasty (TKA). The purpose of this study was to review the clinical cases and perform retrieval analysis of PFA conversions to TKA at our institution. Methods Twenty one patellofemoral arthroplasties in 18 patients that were converted to TKA were identified through our implant retrieval registry. Sixteen implants were available for review by biomechanical engineers, who recorded surface markings, wear patterns, and integrity of fixation. Patient charts were reviewed and time to conversion, tourniquet time, conversion implant, additional surgeries, infections, and Kellgren & Lawrence grade of the tibio-femoral joint on pre-operative radiographs were recorded. Results PFAs converted to TKAs at our institution were implanted for an average of 2.7years. The most common reason for conversion was pain, but most patients had significant tibio-femoral arthritis, as indicated by an average Kellgren & Lawrence grade of 2.6. The average tourniquet time for these conversions was 67min. These patients underwent an average of one additional surgery per PFA converted, and the infection rate of these conversions was approximately 14%. Conclusion Success of PFA depends upon correct patient selection rather than implant failure or wear. Conversion of PFA to TKA is technically similar to primary TKA, with similar post-operative pain relief and range of motion. However, infection rates and complications requiring further surgery are more consistent with results seen in revision TKA. Level of evidence: IV

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.06.015
       
  • Mechanical Analysis of Extra-Articular Knee Ligaments. Part two: Tendon
           grafts used for knee ligament reconstruction
    • Authors: Kristof Smeets; Johan Bellemans; Lennart Scheys; Bert O. Eijnde; Joshua Slane; Steven Claes
      Abstract: Publication date: Available online 5 August 2017
      Source:The Knee
      Author(s): Kristof Smeets, Johan Bellemans, Lennart Scheys, Bert O. Eijnde, Joshua Slane, Steven Claes
      Objectives The aim of this study was to provide information about the mechanical properties of grafts used for knee ligament reconstructions and to compare those results with the mechanical properties of native knee ligaments. Methods Eleven cadaveric knees were dissected for the semitendinosus, gracilis, iliotibial band (ITB), quadriceps and patellar tendon. Uniaxial testing to failure was performed using a standardized method and mechanical properties (elastic modulus, ultimate stress, ultimate strain, strain energy density) were determined. Results The elastic modulus of the gracilis tendon (1458±476MPa) (P <0.001) and the semitendinosus tendon (1036±312MPa) (P <0.05) was significantly higher than the ITB (610±171MPa), quadriceps tendon (568±194MPa), and patellar tendon (417±107MPa). In addition, the ultimate stress of the hamstring tendons (gracilis 155.0±30.7MPa and semitendinosus 120.1±30.0MPa) was significantly higher (P <0.001, respectively P <0.05), relative to the ITB (75.0±11.8MPa), quadriceps tendon (81.0±27.6MPa), and patellar tendon (76.2±25.1MPa). A significant difference (P <0.05) could be noticed between the ultimate strain of the patellar tendon (24.6±5.9%) and the hamstrings (gracilis 14.5±3.1% and semitendinosus 17.0±4.0%). No significant difference in strain energy density between the grafts was observed. Conclusions Material properties of common grafts used for knee ligament reconstructions often differ significantly from the original knee ligament which the graft is supposed to emulate.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.011
       
  • Factors associated with discrepancies between preoperatively planned and
           postoperative alignments in patients undergoing closed-wedge high tibial
           osteotomy
    • Authors: Seong Hwan Kim; Du-Hyun Ro; Young-Min Lee; Yool Cho; Sahnghoon Lee; Myung-Chul Lee
      Abstract: Publication date: Available online 5 August 2017
      Source:The Knee
      Author(s): Seong Hwan Kim, Du-Hyun Ro, Young-Min Lee, Yool Cho, Sahnghoon Lee, Myung-Chul Lee
      Background To evaluate the difference between preoperative plan and postoperative alignment after closed-wedge HTO and determine factors associated with difference. Methods This retrospective cohort study included 165 cases with closed-wedge HTO. The following radiographic parameters were measured: mechanical tibiofemoral angle (mTFA), mechanical medial proximal tibial angle (MPTA), joint line convergence angle, mediolateral joint width discrepancy, Kellgren–Lawrence (K–L) grade, and discrepancy between the correction angle in tibia and correction angle in mTFA. The linear regression analysis was used for the preoperative factors that affect the discrepancy between correction angle in tibia and correction angle in mTFA. Results Preoperative and postoperative mTFA was varus 8.3°±3.7 and valgus 3.1°±2.6. The MPTA was varus 6.2°±3.1 preoperatively, valgus 3.7°±3.0 postoperatively. The mediolateral joint width discrepancy was 3.1mm±1.8 preoperatively and 1.8mm±1.4 postoperatively. The discrepancy between correction angle in tibia and correction angle in mTFA was 1.5°±2.3 valgus. By regression analysis, one degree of valgus overcorrection was found to be related with every 2.5° of joint convergence angle (r2 =0.396), 2.4mm of mediolateral joint width discrepancy (r2 =0.310) and increased one grade of K–L classification (r2 =0.107) as preoperative measurement. Conclusions The 1.5° valgus overcorrection of postoperative mTFA was found compared with planned correction angle in tibia. By the equation, every 2.5° of joint convergence angle and 2.4mm of mediolateral joint width discrepancy preoperatively could predict one degree of valgus overcorrection.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.013
       
  • Mechanical Analysis of Extra-Articular Knee Ligaments. Part One: Native
           knee ligaments
    • Authors: Kristof Smeets; Joshua Slane; Lennart Scheys; Steven Claes; Johan Bellemans
      Abstract: Publication date: Available online 5 August 2017
      Source:The Knee
      Author(s): Kristof Smeets, Joshua Slane, Lennart Scheys, Steven Claes, Johan Bellemans
      Background The aim of this study was to provide a characterization of the tensile properties of the medial collateral ligament (MCL), lateral collateral ligament (LCL), anterolateral ligament (ALL) and medial patellofemoral ligament (MPFL). Our hypothesis was that extra-articular knee ligaments are heterogeneous in nature and possess distinct material properties. Methods MCL (n=12), LCL (n=11), MPFL (n=12) and ALL (n=19) samples from fresh frozen human cadaveric knees were subjected to uniaxial tensile testing to failure and analyzed for their material properties. The elastic modulus (slope of the linear portion of the stress/strain curve), ultimate stress (stress at failure), ultimate strain (strain at failure) and strain energy density (area under the stress/strain curve) were calculated. Results The MCL had the highest elastic modulus (441.8±117.2MPa) and was significantly greater than the MPFL (294.6±190.4MPa) and LCL (289.0±159.7MPa) (P <0.05) as well as the ALL (173.7±91.8MPa) (P <0.001). The ultimate stress was significantly higher (P <0.05) for the LCL (83.6±38.1MPa) and MCL (72.4±20.7MPa), relative to the MPFL (49.1±31.0MPa) and ALL (46.4±20.1MPa). The ultimate strain of the LCL (41.0±9.9%) and ALL (37.8±7.9%) were significantly higher (P <0.05) compared to the MCL (22.9±2.5%) and MPFL (22.2±5.6%). The strain energy density of the LCL (15.2±6.4MPa) was significantly greater (P <0.05) than all other ligaments (ALL 7.8±3.1MPa, MCL 7.5±2.9MPa and MPFL 5.0±2.9MPa). Conclusions Extra-articular knee ligaments are a heterogeneous group with respect to material characteristics. Each ligament has tensile properties that are significantly different from others and treatment strategies should take these findings into account.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.07.013
       
  • Double-bundle anterior cruciate ligament reconstruction with and without
           remnant preservation — Comparison of early postoperative outcomes and
           complications
    • Authors: Hiroshi Nakayama; Syunichiro Kambara; Tomoya Iseki; Ryo Kanto; Kenji Kurosaka; Shinichi Yoshiya
      Abstract: Publication date: Available online 5 August 2017
      Source:The Knee
      Author(s): Hiroshi Nakayama, Syunichiro Kambara, Tomoya Iseki, Ryo Kanto, Kenji Kurosaka, Shinichi Yoshiya
      Background To compare the early postoperative outcomes and complications of double-bundle anterior cruciate ligament (ACL) reconstruction with and without remnant preservation. Methods The study population comprised 125 consecutive knees that underwent double-bundle ACL reconstruction using hamstring autograft. Among the 125 knees, remnant preservation was indicated for 50 knees, while standard double-bundle reconstruction was performed in the remaining 75 knees. Postoperative evaluations included heel-height difference (HHD) at periodical follow-ups, number of knees requiring arthroscopic debridement due to problematic extension loss within six months, re-injury within one year, graft status upon second-look arthroscopy, and clinical examinations by Lysholm score and KT measurement at one year. Results All patients could be followed up for a minimum of one year after surgery. When the results obtained from both groups were compared, HHD values were significantly larger in the preservation group at three and six months, and the rate of knees requiring arthroscopic debridement was also higher in this group (12% versus 4.0%). Graft status on second-look arthroscopy was considered to be good for 92% of the knees in the preservation group versus 59% in the non-preservation group. Re-injury rates within one year were 2.0% in the preservation group and 5.3% in the non-preservation group. No significant differences in clinical examinations were found between the groups at one year. Conclusions Remnant preservation in double-bundle hamstring autograft ACL reconstruction may enhance tissue healing; however, retention of the remnant with its full volume resulted in an increased incidence of postoperative problematic extension loss.

      PubDate: 2017-08-14T16:11:39Z
      DOI: 10.1016/j.knee.2017.05.008
       
  • Contents List
    • Abstract: Publication date: August 2017
      Source:The Knee, Volume 24, Issue 4


      PubDate: 2017-07-18T21:43:53Z
       
  • Optimization of sagittal and coronal planes with robotic-assisted
           unicompartmental knee arthroplasty
    • Authors: Michael A. Gaudiani; Benedict U. Nwachukwu; Jayesh V. Baviskar; Mrinal Sharma; Anil S. Ranawat
      Abstract: Publication date: Available online 1 June 2017
      Source:The Knee
      Author(s): Michael A. Gaudiani, Benedict U. Nwachukwu, Jayesh V. Baviskar, Mrinal Sharma, Anil S. Ranawat
      Background One of the anatomic goals of total knee arthroplasty (TKA) is optimizing in the coronal and sagittal plane. Accurate alignments of both planes have been correlated to functional outcome and range of motion. There is a paucity of evidence on the accuracy of unicompartmental knee arthroplasty (UKA) in balancing biplanar knee alignment – specifically sagittal plane alignment. Because robotic assisted UKA has an advantage of more accurately manipulating sagittal plane for optimal alignment and kinematics based on pre-operative and intraoperative CT planning we assessed the accuracy. Methods We reviewed the clinical and radiographic information of 94 robotic assisted UKA surgeries for balancing of sagittal and coronal knee anatomy using radiographic parameters, such as posterior condylar offset ratio (PCOR), posterior tibial slope (PTS), femoral-tibial angle, and joint line. Results In the sagittal plane, we found no significant difference between pre and postoperative PCOR values. As planned, PTS was significantly lower after UKA compared to the native knee (4.91° vs 2.28°; p<0.0001). In the coronal plane, there was no significant difference in the joint line however pre and post-operative mechanical axis were significantly different (5.43°±2.58 of varus vs. 2.76°±2.14 of varus; p<0.0001). Conclusion This study attempts to quantify sagittal and coronal plane alignment after robotic assisted UKA. More attention should be paid to the role of sagittal plane alignment after UKA. We believe modifying posterior tibial slope, while maintaining PCOR is fundamental in achieving native kinematics and optimizing range of motion in the sagittal plane. This may be best-accomplished using robotic techniques for UKA.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.05.002
       
  • Coronal alignment predicts the use of semi-constrained implants in
           contemporary total knee arthroplasty
    • Authors: J. Ryan Martin; Keith A. Fehring; Chad D. Watts; Daniel L. Levy; Bryan D. Springer; Raymond H. Kim
      Abstract: Publication date: Available online 30 May 2017
      Source:The Knee
      Author(s): J. Ryan Martin, Keith A. Fehring, Chad D. Watts, Daniel L. Levy, Bryan D. Springer, Raymond H. Kim
      Background Semi-constrained, or varus–valgus constrained, implants are occasionally necessary to achieve stability in primary total knee arthroplasty (TKA). However, outcomes with these implants are largely unknown. Therefore, the primary goals of this study were to determine 1) can we identify preoperatively which patients might require a semi-constrained implant and 2) are there any clinical and or radiographic differences for those that require a semi-constrained implant? Methods A multicenter retrospective study was performed to retrospectively review patients that had a Stryker Triathlon (Kalamazoo, MI) TKA with a Total Stabilized (TS) tibial insert (n=75). This TS cohort was subsequently matched 1:1 based on age, gender, and BMI to a cohort of patients with the same primary TKA design with a PS insert (n=75). Preoperative and postoperative radiographic and clinical data were compared between the two groups. Results Preoperatively, the TS cohort had significantly greater varus (9.72 vs. 3.48; p=0.0001) and valgus (14.1 vs. 7.57; p=0.0001) deformity. Post-operatively, there were no statistically significant differences in revisions (p=1), reoperations (p=1), or complications (p=1). Mean clinical and radiographic follow-ups were equivalent between groups (25.5 vs. 25.8months, p=0.8851). Conclusion As suspected, use of a semi-constrained insert to achieve intraoperative coronal stability was most predicted by preoperative coronal deformity (either varus or valgus). Longer follow-up and larger patient cohorts are necessary to determine.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.03.013
       
  • Mobile bearing medial unicompartmental knee arthroplasty in patients whose
           lifestyles involve high degrees of knee flexion: A 10–14year follow-up
           study
    • Authors: Won Sik Choy; Kwang Won Lee; Ha Yong Kim; Kap Jung Kim; Young Sub Chun; Dae Suk Yang
      Abstract: Publication date: Available online 30 May 2017
      Source:The Knee
      Author(s): Won Sik Choy, Kwang Won Lee, Ha Yong Kim, Kap Jung Kim, Young Sub Chun, Dae Suk Yang
      Background Because Asian populations have different lifestyles, such as squatting and sitting on the floor, from those of Western populations, it is possible that the clinical results and survival rate of unicompartmental knee arthroplasty (UKA) for Asian patients may be different. This study described outcomes of mobile bearing medial UKA for Korean patients. Methods A total of the 164 knees treated with mobile bearing UKAs in 147 patients (14 males and 133 females) were reviewed. The mean follow-up period was 12.1years (range 10.1–14). Results The clinical outcomes, such as the Hospital for Special Surgery Knee score, the Oxford Knee Score and the Knee Society rating system, showed statistically significant improvement from pre-operative to final follow-up (P <0.05). A total of 26 UKAs (15.8%) required revision; the most common reason was bearing dislocation. The 95% confidence interval of survival rate at 12years was 84.1%, with revision for any reason as the end point. Conclusions Minimally invasive mobile bearing UKA in Asian patients who required high degrees of knee flexion showed rapid recovery and good clinical outcome. However, they also showed relatively high rates of bearing dislocation and aseptic loosening. Therefore, mobile bearing UKA should only be performed in patients whose lifestyle involves high flexions after carefully considering these risks and benefits.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.05.004
       
  • Variability in static alignment and kinematics for kinematically aligned
           TKA
    • Authors: Willy Theodore; Joshua Twiggs; Elizabeth Kolos; Justin Roe; Brett Fritsch; David Dickison; David Liu; Lucy Salmon; Brad Miles; Stephen Howell
      Abstract: Publication date: Available online 30 May 2017
      Source:The Knee
      Author(s): Willy Theodore, Joshua Twiggs, Elizabeth Kolos, Justin Roe, Brett Fritsch, David Dickison, David Liu, Lucy Salmon, Brad Miles, Stephen Howell
      Background Total knee arthroplasty (TKA) significantly improves pain and restores a considerable degree of function. However, improvements are needed to increase patient satisfaction and restore kinematics to allow more physically demanding activities that active patients consider important. The aim of our study was to compare the alignment and motion of kinematically and mechanically aligned TKAs. Methods A patient specific musculoskeletal computer simulation was used to compare the tibio-femoral and patello-femoral kinematics between mechanically aligned and kinematically aligned TKA in 20 patients. Results When kinematically aligned, femoral components on average resulted in more valgus alignment to the mechanical axis and internally rotated to surgical transepicondylar axis whereas tibia component on average resulted in more varus alignment to the mechanical axis and internally rotated to tibial AP rotational axis. With kinematic alignment, tibio-femoral motion displayed greater tibial external rotation and lateral femoral flexion facet centre (FFC) translation with knee flexion than mechanical aligned TKA. At the patellofemoral joint, patella lateral shift of kinematically aligned TKA plateaued after 20 to 30° flexion while in mechanically aligned TKA it decreased continuously through the whole range of motion. Conclusions Kinematic alignment resulted in greater variation than mechanical alignment for all tibio-femoral and patello-femoral motion. Kinematic alignment places TKA components patient specific alignment which depends on the preoperative state of the knee resulting in greater variation in kinematics. The use of computational models has the potential to predict which alignment based on native alignment, kinematic or mechanical, could improve knee function for patient's undergoing TKA.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.04.002
       
  • Tibial insertions of the anterior cruciate ligament and the anterior horn
           of the lateral meniscus: A histological and computed tomographic study
    • Authors: Masashi Kusano; Yasukazu Yonetani; Tatsuo Mae; Ken Nakata; Hideki Yoshikawa; Konsei Shino
      Abstract: Publication date: Available online 27 May 2017
      Source:The Knee
      Author(s): Masashi Kusano, Yasukazu Yonetani, Tatsuo Mae, Ken Nakata, Hideki Yoshikawa, Konsei Shino
      Background A positional relationship between the anterior cruciate ligament (ACL) and the anterior horn of the lateral meniscus (AHLM) has not previously been a topic of interest in the literature because the AHLM is already known to be obviously adjacent to the ACL and is assumed as a lateral border. The objective of this study was to investigate the positional anatomic relationship between the ACL and AHLM by histological evaluation of sequential slices and computed tomography (CT) of the tibial insertion sites. Hypothesis/purpose The ACL has a specific positional relationship with the AHLM and there is an identifiable distinct bony border between them. The position of the AHLM could be an important and useful landmark for accurate tibial tunnel positioning in anatomical ACL reconstruction. Study design Descriptive laboratory study. Methods Twelve ACL-intact knees from embalmed cadavers were used in this study. Six knees were sectioned into four slices for histologic examination in the coronal planes parallel to the AHLM alignment. Before sectioning, these knees were subjected to three-dimensional (3-D) volume-rendering CT. Each of the four slices demonstrated the insertion area of the ACL relative to the position of the AHLM. Each histologic slice was compared with the corresponding CT image. Only histological examination in the sagittal planes was performed in the other six knees. Results The ACL fibres were broadly attached at the region anterior to the AHLM. However, the ACL and AHLM shared a clear border identifiable on the coronal CT images and appeared as a prominence of the bony ridge on the 3-D CT images. No dense ACL fibres were attached to the region posterior to the AHLM. Based on the histological data, the geometry of the ACL tibial insertion was L-shaped along the AHLM. Conclusion The ACL and AHLM have a specific positional relationship not only in the mediolateral direction but also anteroposteriorly. The AHLM serves not only as a lateral border, but also as a useful reference in an anterioposterior direction for tunnel positioning in ACL reconstruction. Specifically, the ACL fibres were found to be broadly attached onto the bony surface in the region anterior to the AHLM and there was no firm attachment of the ACL in the region posterior to the AHLM on the tibial side, which is useful in avoiding posterior tunnel placement.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.04.014
       
  • ACL graft metabolic activity assessed by 18FDG PET–MRI
    • Authors: Robert A. Magnussen; Katherine Binzel; Jun Zhang; Wenbo Wei; Melanie U. Knopp; David C. Flanigan; Timothy E. Hewett; Christopher C. Kaeding; Michael V. Knopp
      Abstract: Publication date: Available online 27 May 2017
      Source:The Knee
      Author(s): Robert A. Magnussen, Katherine Binzel, Jun Zhang, Wenbo Wei, Melanie U. Knopp, David C. Flanigan, Timothy E. Hewett, Christopher C. Kaeding, Michael V. Knopp
      Background To demonstrate the use of 18Fluorodeoxyglucose positron emission tomography (PET) and magnetic resonance imaging (MRI) in combination (18FDG-PET) to assess the metabolic activity of ACL graft tissue and evaluate the utility of this technique for ligament imaging. Methods Twenty-one knees with intact ACL grafts in 19 patients at multiple time points following ACL reconstruction were recruited to participate. PET–MRI imaging was performed using a custom device to place knees in the same position for both studies. Images were co-registered for quantification of 18FDG-PET standardized uptake value (SUV) for the proximal, middle, and distal ACL was quantified. Signal in extra-articular muscle tissue in the index knee was also recorded as a control. Signal from each location was compared based on how far post-operative each knee was from ACL reconstruction (<6months, six to 12months, 12–24months, or >24months). Results Significant differences in 18FDG PET SUV between the four time points were observed in the proximal (p=0.02), middle (p=0.004), and distal (p=0.007) portions of the ACL graft. The greater than 24months group was noted to be different from other groups in each case. No difference in PET 18FDG SUV was noted in the extra-articular muscle in the index knee in each time group (p=0.61). Conclusions Metabolic activity was noted to be significantly lower in grafts imaged greater than two years post-reconstruction relative to those grafts that had been in place for shorter periods of time.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.04.008
       
  • Detection of bone defects around zirconium component after total knee
           arthroplasty
    • Authors: Yukihide Minoda; Kazumasa Yamamura; Kazutaka Sugimoto; Shigekazu Mizokawa; Shingo Baba; Hiroaki Nakamura
      Abstract: Publication date: Available online 26 May 2017
      Source:The Knee
      Author(s): Yukihide Minoda, Kazumasa Yamamura, Kazutaka Sugimoto, Shigekazu Mizokawa, Shingo Baba, Hiroaki Nakamura
      Background It is difficult to detect bone defects caused by loosening or osteolysis around the femoral component after total knee arthroplasty (TKA) because the thick metal hinders visualization of bone defects. Previous reports have shown that tomosynthesis, a novel tomographic technique, is advantageous over fluoroscopically guided plain radiography, computed tomography (CT) and magnetic resonance imaging (MRI) for the early detection of bone defects around a conventional cobalt–chromium alloy component. However, there have been no reports on a zirconium component. The purpose of this study was to examine the sensitivity and specificity of the detection of bone defects around a zirconium component using fluoroscopically guided plain radiography, tomosynthesis, CT and MRI. Methods Six zirconium femoral components were implanted in pig knees. Two were cemented without any bone defects. Two were cemented with cystic defects. Two were cemented with four-millimeter-thick defects between the bone cement and the bone. Defects were filled with agarose gel. Eight orthopedic surgeons examined the fluoroscopically guided plain radiography, tomosynthesis, CT and MRI images. Sensitivity and specificity of each method were analyzed. Results No bone defects were detected with plain radiography. The sensitivity and specificity of tomosynthesis were 21.9% and 36.8%, respectively. The sensitivity and specificity of CT were 15.1% and 33.0%, respectively. The sensitivity and specificity of MRI were 84.4% and 86.6%, respectively. Conclusions For the detection of bone defects around a zirconium component after TKA, MRI is advantageous over fluoroscopically guided plain radiography, tomography and CT, in terms of sensitivity and specificity.

      PubDate: 2017-06-06T22:09:14Z
      DOI: 10.1016/j.knee.2017.04.020
       
 
 
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