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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: Caroline Hing; Oday Al-Dahah
      First page: 897
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Caroline Hing, Oday Al-Dahah

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.08.057
  • Early or delayed reconstruction in multi-ligament knee injuries: A
           systematic review and meta-analysis
    • Authors: Erik Hohmann; Vaida Glatt; Kevin Tetsworth
      Pages: 909 - 916
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Erik Hohmann, Vaida Glatt, Kevin Tetsworth
      Background Whether early or delayed surgical intervention in patients with multi-ligament injuries results in better outcomes, is of current and controversial debate. Purpose The purpose of this study was to perform a meta-analysis comparing early versus late surgical treatment of multi-ligament knee injuries. Methods We performed a systematic review of Medline, Embase, Scopus, and Google Scholar to identify relevant studies in the English and German literature. Eligibility criteria included studies comparing early or delayed surgical interventions for multi-ligament knee injuries, with a minimum follow-up of two years, reporting the primary clinical outcome using a validated functional scoring system and range of motion. Exclusion criteria were patients treated with multi-trauma, head injury, non-union, lower extremity fractures, or a documented history of previous knee injuries. Publication bias was assessed by funnel plot, and the risk of bias was established using the Cochrane Collaboration's risk of bias tool. Heterogeneity was assessed using χ2 and I2 statistic. Results Eight studies (n=260 patients) were included in the analysis. 149 patients were treated early with a mean of 10.6days; 111 patients were treated late with a mean of 294days. The pooled estimate for clinical outcome demonstrated that early surgery resulted in significantly higher Lysholm scores (SMD 0.669, 95% CI: 0.379 to 0.959, p=0.0001, I2 =0%). Thirty-one per cent of all patients with early surgery had a normal or near normal knee, whereas only 15% of patients with late reconstruction reported the knee to be normal or near normal. The pooled estimates for total ROM did not demonstrate a significant difference between the groups (SMD 0.113, 95% CI: −0.271 to 0.498, p=0.564, I2 =35.57%). Conclusions The results of this meta-analysis suggest that early surgical intervention in multi-ligament injuries of the knee produces a significantly superior clinical outcome, compared to late reconstruction. Although an overall trend of improved total range of knee motion was also demonstrated, this was very small and unlikely to be clinically relevant. Level of evidence Level 4; Systematic review and meta-analysis.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.011
  • Body mass index as a predictor of outcome in total knee replace: A
           systemic review and meta-analysis
    • Authors: Kai Sun; Hui Li
      Pages: 917 - 924
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Kai Sun, Hui Li
      Background To conduct a meta-analysis with randomized controlled trials (RCTs) published in full text to demonstrate database to show the associations of perioperative, postoperative outcomes of normal and high body mass index (BMI) to provide the predictive diagnosis for clinic. Methods Literature search was performed in PubMed, Embase, Web of Science and Cochrane Library for information from the earliest date of data collection to February. RCTs comparing the benefits and risks of normal BMI with those of high BMI in primary total knee arthroplasty (TKA) were included. Statistical heterogeneity was quantitatively evaluated by X2 test with the significance set P<0.10 or I2 >50%. Results Seven RCTs consisting of 33,778 patients were included. (6065 normal BMI patient; 27,713 high BMI). The results showed that high BMI was related to a greater increase in operative time, post-operative range of motion (ROM), post-operative Knee Society and function scores (KSS), infection rate (P<0.1). No differences in pulmonary embolism and perioperative mortality rates were found between normal and high body mass index patients with follow-up≥5years (P>0.1). Conclusions Compared with normal BMI patients, high BMI patients demonstrated an increased risk of perioperative and postoperative complications and clear difference about complications between normal and high BMI about TKA.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.05.022
  • A new femoral fixation device for anterior cruciate ligament
           reconstruction using the outside-in technique and hamstring tendon graft:
           A comparison between two devices in cadaveric human knee models
    • Authors: Suri Chong; Dai-Soon Kwak; Dhanasekaraprabu Balasubramanian; Young Dong Song; Young Gon Na; Tae Kyun Kim
      Pages: 925 - 932
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Suri Chong, Dai-Soon Kwak, Dhanasekaraprabu Balasubramanian, Young Dong Song, Young Gon Na, Tae Kyun Kim
      Background A new device (T-anchor) was developed for ACL reconstruction and is implanted via the outside-in technique using hamstring grafts. The purpose of this study was to compare the T-anchor with the EndoButton Direct. Methods This study was conducted on 30 cadaveric knees (15 matched pairs). There were two groups of 15 each in the T-anchor and EndoButton Direct groups. After the harvest of grafts, fixation site profile and graft length were measured by loading the grafts onto both devices. They were then tested on a universal testing machine to assess elongation after cyclic loading, load to failure, ultimate load, and mode of failure. Results The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3±0.4mm vs. 4.7±1.0mm, P <0.001). The length of the graft-device complex of the T-anchor specimens was longer than that of the EndoButton Direct specimens (125.0±8.9mm vs. 115.0±8.7mm, P <0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4±0.6mm vs. 3.9±2.6mm, P =0.015). There was no statistically significant difference in ultimate load and load to failure between the T-anchor and EndoButton Direct groups. For mode of failure, the T-anchor fared better (P =0.013) with all failures attributed to specimens. Conclusions In this cadaveric study, the new device, T-anchor, performed better than the EndoButton Direct with respect to the above-mentioned study parameters except for ultimate load and load to failure.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.003
  • A novel, hydroxyapatite-based screw-like device for anterior cruciate
           ligament (ACL) reconstructions
    • Authors: Thomas C. Schumacher; Kamen Tushtev; Ulrich Wagner; Caroline Becker; Marzellus große Holthaus; Sebastian B. Hein; Janne Haack; Christian Heiss; Markus Engelhardt; Thaqif El Khassawna; Kurosch Rezwan
      Pages: 933 - 939
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Thomas C. Schumacher, Kamen Tushtev, Ulrich Wagner, Caroline Becker, Marzellus große Holthaus, Sebastian B. Hein, Janne Haack, Christian Heiss, Markus Engelhardt, Thaqif El Khassawna, Kurosch Rezwan
      Background Rupture of the anterior cruciate ligament (ACL) is one of the most common injuries of the knee. Common techniques for ACL reconstruction require a graft fixation using interference screws. Nowadays, these interference screws are normally made of titanium or polymer/ceramic composites. The main challenge of application of a fixation device made entirely of bioactive ceramic is in relation to the low strength of such materials. The purpose of this study was to evaluate a novel geometry for a fixation device made of pure hydroxyapatite for ACL reconstructions that can overcome some problems of the titanium and the polymer/ceramic screws. Methods Finite Element Analysis was used for optimization of the stress distribution in conventional interference screw geometry. For experimental evaluation of the new fixation device, ex vivo tests were performed. Results The innovative screw-like fixation device is characterized by multiple threads with a large thread pitch. The novel design enabled the insertion of the screw into the bone without the application of an external torque or a screwdriver. In turn, it also allowed for the use of low-strength and high-bioactivity materials, like hydroxyapatite. Ex vivo tests showed that the novel screw can sustain pull-out forces up to 476 N, which is comparable to that of the commercially available BioComposite™ interference screws (Arthrex Inc., Germany), as a reference. Conclusions In summary, the novel screw design is a promising strategy to develop all-ceramic fixation devices for ACL reconstructions, which may eliminate some drawbacks of the current interference screws.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.07.005
  • Surgical management of posterior knee dislocation associated with extensor
           apparatus rupture
    • Authors: Chang-Cheng Liu; Xing Gao; Ming Xu; Zhi-Gang Kong
      Pages: 940 - 948
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Chang-Cheng Liu, Xing Gao, Ming Xu, Zhi-Gang Kong
      Objective The purpose of this study was to report the clinical and functional results of patients who underwent surgical management for posterior knee dislocation associated with extensor apparatus rupture. Introduction Posterior knee dislocations associated with extensor apparatus ruptures are defined as rare but complicated injuries, which are difficult to return to the level of activity prior to the injury. The study demonstrated a hypothesis that good knee stability and early gain of range of motion could be achieved with deliberate design of the treatment protocol and proper application of the instruments. Methods Fifteen patients with posterior knee dislocations associated with extensor apparatus ruptures were evaluated after reduction and repair of extensor apparatus. Following that, multiple-ligament reconstruction in association with use of a lateral knee-spanning external fixator was applied for at least six weeks. Ligament reconstructions were performed using allografts. Range of motion and knee stability were both measured at each follow-up evaluation at a mean time of 36months. The assessment was made using the Lysholm Knee Scoring Scale. Results The mean Lysholm scale score was 87.6 (range 73–95), with excellent in 11 cases, good in two, and fair in two. In the final evaluation, the range of motion was a mean range of 123.4° (range 100–135). Conclusion The use of a lateral knee-spanning external fixator ensured the safety of repaired vessels, knee stability after reduction, and early rehabilitation with range of motion.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.05.023
  • Biomechanical tensile strength analysis for medial patellofemoral ligament
    • Authors: Patrick W. Joyner; Jeremy Bruce; Travis S. Roth; Frederic Baker Mills; Scott Winnier; Ryan Hess; Luke Wilcox; Aaron Mates; Tim Frerichs; James R. Andrews; Charles A. Roth
      Pages: 965 - 976
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Patrick W. Joyner, Jeremy Bruce, Travis S. Roth, Frederic Baker Mills, Scott Winnier, Ryan Hess, Luke Wilcox, Aaron Mates, Tim Frerichs, James R. Andrews, Charles A. Roth
      Background Medial patellofemoral ligament (MPFL) reconstruction is a surgery for acute and chronic dislocating patella. Several surgical techniques have been described. No biomechanical study has compared suture anchors, interference screws, and suspensory cortical fixation for MPFL reconstruction using human gracilis allograft. Methods Twelve human cadaver knees were used for the analysis of five MPFL reconstruction techniques on the femur (F) and patella (P): suspensory cortical (SC), interference screw (IS) and suture anchor (SA) fixation (SC-F/SC-P, SC-F/IS-P, SC-F/SA-P, IS-F/SC-P, IS-F/IS-P). Each method was examined six times, each using a new human gracilis allograft. The force necessary for 50% patellar displacement and 100% patellar displacement were recorded for each method. Additionally, we examined the peak force to fixation failure for all methods. Patella dislocation or loss of fixation was considered failure. Results SC-F/SC-P, IS-F/SC-P, and SC-F/IS-P required force to failure greater than that of the native MPFL. The SC-F/IS-P required the largest force to failure. The SC-F/SA-P fixation technique required significantly less force to failure (P<0.05) than the native MPFL and significantly less force to failure (P<0.05) than all four other fixation techniques. All methods of fixation employing an interference screw failed secondary to graft pullout at the interference screw-bone interface. Methods employing suture anchors and two suspensory cortical fixations failed at the graft-suture anastomosis. Conclusion SC-F/SC-P, IS-F/SC-P, and SC-F/IS-P fixations were found to be stronger than the native MPFL, with the strongest being SC-F/IS-P.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.04.013
  • Effects of an over-ground exoskeleton on external knee moments during
           stance phase of gait in healthy adults
    • Authors: Chris A. McGibbon; Scott C.E. Brandon; Marcus Brookshaw; Andrew Sexton
      Pages: 977 - 993
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Chris A. McGibbon, Scott C.E. Brandon, Marcus Brookshaw, Andrew Sexton
      Background Physical activity and exercise is central to conservative management of knee osteoarthritis (KOA), but is often difficult for patients with KOA to maintain over the decade or more prior to surgical management. Better approaches are needed for maintaining physical function and health in this population that can also address the patho-biomechanics of the osteoarthritic knee. The objective of the study is to quantify how a lower-extremity robotic exoskeleton (dermoskeleton) modifies the external knee moments during over-ground walking in a sample of healthy adults, and to evaluate these biomechanical modifications in the context of the osteoarthritic knee. Method Motion analysis data was acquired for 13 participants walking with and without the dermoskeleton. Force plate data, external knee moment arms, and knee moments in the laboratory and tibia frames of reference were computed, as well as time–distance parameters of walking, and compared between the two conditions. Results Although gait speed was not different, users took shorter and wider steps when walking with the dermoskeleton. Ground reaction forces and early-stance knee moment increased due to the added mass of the dermoskeleton, but the knee adduction moment was significantly reduced in late stance phase of gait. There was no effect on the knee torsional moment when measured in the anatomical frame of reference, and the late-stance knee flexion moment was invariant. Conclusions The dermoskeleton demonstrated favorable biomechanical modifications at the knee in healthy adults while walking. Studies are warranted to explore this technology for enabling physical activity-based interventions in patients with KOA.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.04.004
  • Computational modelling of motion at the bone–implant interface after
           total knee arthroplasty: The role of implant design and surgical fit
    • Authors: Noel Conlisk; Colin R. Howie; Pankaj Pankaj
      Pages: 994 - 1005
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Noel Conlisk, Colin R. Howie, Pankaj Pankaj
      Background Aseptic loosening, osteolysis, and infection are the most commonly reported reasons for revision total knee arthroplasty (TKA). This study examined the role of implant design features (e.g. condylar box, pegs) and stems in resisting loosening, and also explored the sensitivity of the implants to a loose surgical fit due to saw blade oscillation. Methods Finite element models of the distal femur implanted with four different implant types: cruciate retaining (CR), posterior stabilising (PS), total stabilising (TS) with short stem (12mm×50mm), and a total stabilising (TS) with long stem (19mm×150mm) were developed and analysed in this study. Two different fit conditions were considered: a normal fit, where the resections on the bone exactly match the internal profile of the implant, and a loose fit due to saw blade oscillation, characterised by removal of one millimetre of bone from the anterior and posterior surfaces of the distal femur. Frictional interfaces were employed at the bone–implant interfaces to allow relative motions to be recorded. Results The results showed that interface motions increased with increasing flexion angle and loose fit. Implant design features were found to greatly influence the surface area under increased motion, while only slightly influencing the values of peak motion. Short uncemented stems behaved similarly to PS implants, while long canal filling stems exhibited the least amount of motion at the interface under any fit condition. Conclusion In conclusion, long stemmed prostheses appeared less susceptible to surgical cut errors than short stemmed and stemless implants.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.07.003
  • Tunnel widening after ACL reconstruction with aperture screw fixation or
           all-inside reconstruction with suspensory cortical button fixation
    • Authors: Raul Mayr; Vinzenz Smekal; Christian Koidl; Christian Coppola; Josef Fritz; Ansgar Rudisch; Christof Kranewitter; René Attal
      Pages: 1047 - 1054
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Raul Mayr, Vinzenz Smekal, Christian Koidl, Christian Coppola, Josef Fritz, Ansgar Rudisch, Christof Kranewitter, René Attal
      Background Tunnel widening after anterior cruciate ligament reconstruction (ACLR) is influenced by the surgical and fixation techniques used. Computed tomography (CT) is the most accurate image modality for assessing tunnel widening, but magnetic resonance imaging (MRI) might also be reliable for tunnel volume measurements. In the present study tunnel widening after ACLR using biodegradable interference screw fixation was compared with all-inside ACLR using button fixation, with tunnel volume changes being measured on CT and MRI scans. Study design Randomized controlled trial; Level of evidence, 2. Methods Thirty-three patients were randomly assigned to hamstring ACLR using a biodegradable interference screw or all-inside cortical button fixation. CT and MRI scanning were done at the time of surgery and six months after. Tunnel volume changes were calculated and compared. Results On CT, femoral tunnel volumes changed from the postoperative state (100%) to 119.8% with screw fixation and 143.2% with button fixation (P =0.023). The changes in tibial tunnel volumes were not significant (113.9% vs. 117.7%). The changes in bone tunnel volume measured on MRI were comparable with those on CT only for tunnels with interference screws. Tibial tunnels with button fixation were significantly underestimated on MRI scanning (P =0.018). Conclusions All-inside ACLR using cortical button fixation results in increased femoral tunnel widening in comparison with ACLR with biodegradable interference screw fixation. MRI represents a reliable imaging modality for future studies investigating tunnel widening with interference screw fixation.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.007
  • Associations of isokinetic and isotonic knee strength with knee function
           and activity level after anterior cruciate ligament reconstruction: a
           prospective cohort study
    • Authors: Yong-Hao Pua; Jia-Ying Ho; Suelyn Ai-Sim Chan; Shin-Jiun Khoo; Hwei-Chi Chong
      Pages: 1067 - 1074
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Yong-Hao Pua, Jia-Ying Ho, Suelyn Ai-Sim Chan, Shin-Jiun Khoo, Hwei-Chi Chong
      Background Although isokinetic dynamometry often serves as a reference to assess the concurrent validity of weight-machine isotonic strength testing, it is unknown whether isokinetic knee strength is associated with knee function and activity level more strongly than isotonic knee strength in patients with an anterior cruciate ligament reconstruction (ACLR). This study aimed to compare the associations of isokinetic and isotonic knee strength with knee function and work-and-sports activity levels in patients with ACLR. Methods One-hundred and six patients with a unilateral ACLR participated. At three months post-ACLR, isokinetic quadriceps and hamstrings strength was measured using an isokinetic dynamometer whilst isotonic strength was measured using weight machines. At six months post-ACLR, patients performed the single-leg hop-for-distance test. Self reported knee function and work-and-sports activity levels were assessed by the Lysholm Knee Score and Tegner Activity Score, respectively. Results In multivariable analyses, isotonic and isokinetic quadriceps strength limb symmetry indices (LSIs) were significantly associated with all outcomes (P ≤0.03) and had comparable predictive performance. Isotonic and isokinetic hamstrings strength LSIs were significantly associated with Lysholm scores (P ≤0.03) and isotonic hamstrings strength was additionally significantly associated with hop-for-distance LSI (P =0.01). Conclusions Weight machine-derived isotonic quadriceps strength was independently and consistently associated with knee function and work-and-sport activity level post-ACLR. Isokinetic knee strength was not more strongly associated than isotonic knee strength with the various outcomes. These findings have logistic and economic implications because the isokinetic dynamometer system is relatively expensive and its operation requires more logistic effort and technical skills.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.014
  • 3-Tesla MRI: Beneficial visualization of the meniscofemoral ligaments'
    • Authors: Johanna Ebrecht; Andrej Krasny; Dinah Maria Hartmann; Marcia Viviane Rückbeil; Thomas Ritz; Andreas Prescher
      Pages: 1090 - 1098
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Johanna Ebrecht, Andrej Krasny, Dinah Maria Hartmann, Marcia Viviane Rückbeil, Thomas Ritz, Andreas Prescher
      Background Recent investigations have confirmed an important stabilizing and protective function of the meniscofemoral ligaments (MFLs) to the knee joint and suggest a clinical relevance. Concerning their incidences, however, there have been discrepancies between data acquired from cadaveric studies and MRI data using 0.3- to 1.5-Tesla field strengths probably due to lower resolution. This study aims to investigate whether imaging with 3-Tesla magnetic resonance imaging (3-T MRI) is beneficial in gaining information regarding the ligaments' incidence, length, width and anatomic variation. Methods 3-T MRI images of 448 patients (224 males, 224 females, with, respectively, 32 patients of each sex in the age groups: 0–20, 21–30, 31–40, 41–50, 51–60, 61–70, >70years) were retrospectively reviewed. The influence of the parameters ‘sex’ and ‘age’ was determined. Results Whereas 71% of the patients had at least one MFL, 22% had an anterior MFL (aMFL), 53% had a posterior MFL (pMFL) and five percent had coexisting ligaments. The pMFLs were more likely to be present in female patients (P <0.05) but if so, they were longer in the males (P <0.05). The pMFL was categorized according to its insertion on the medial femoral condyle. Conclusions 3-T MRI enables an excellent illustration of the anatomic variations of pMFLs. By modifying an anatomic classification for radiological use we measured lengths and widths of the MFLs without any difficulties. Despite its increased resolution, 3-T MRI lends no diagnostic benefit in visualizing the course of the aMFL or filigree coexisting ligaments as compared to MRI at lower field strengths.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.07.002
  • No change in patellar height following open wedge high tibial osteotomy
           using a novel femur-referenced measurement method
    • Authors: C. Ihle; M. Ahrend; L. Grünwald; A. Ateschrang; U. Stöckle; S. Schröter
      Pages: 1118 - 1128
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): C. Ihle, M. Ahrend, L. Grünwald, A. Ateschrang, U. Stöckle, S. Schröter
      Background Open wedge high tibial osteotomy (HTO) can influence the tibial slope and thereby the landmarks of currently used patellar height indices. The purpose of this retrospective study was to compare and validate a new femur-referenced patella height measurement method to currently used patellar height indices in a cohort of HTO patients. Methods Patellar height (Caton–Deschamps, Blackburne–Peel and Insall–Salvati Indices and our newly developed Femoral Patellar Height Index) as well as tibial slope were analysed. Full-weight-bearing long-leg anteroposterior radiographs as well as anteroposterior and lateral radiographs of the knee in 0° of extension were used. Radiographs were performed preoperatively, and at six weeks, three, six, 12 and 18months postoperatively. Measurements were recorded twice by two observers. The second observation was performed after a delay of three months. Results A total of 99 patients with a mean age of 46.2±8years were included. A statistically significant pre- to postoperative increase in tibial slope was found in all methods. Patellar height decreased according to Caton–Deschamps and Blackburne–Peel Indices. The Insall–Salvati Index as well as the novel Femoral Patellar Height Index remained unchanged. Intra-rater (interclass correlation coefficient (ICC) 0.914–0.998) and inter-rater (ICC 0.955–0.989) reliability were highest in the new index. Conclusion Detected changes of patellar height following open wedge HTO depend on the method used. Tibial slope increases following surgery. Our new index with a femoral reference for measuring patellar height was validated and good to excellent intra- and inter-rater reliability were demonstrated. Following HTO, the Femoral Patellar Height Index can be recommended as a standardized method to measure patellar height.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.006
  • ß-TCP bone substitutes in tibial plateau depression fractures
    • Authors: Tim Rolvien; Florian Barvencik; Till Orla Klatte; Björn Busse; Michael Hahn; Johannes Maria Rueger; Martin Rupprecht
      Pages: 1138 - 1145
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Tim Rolvien, Florian Barvencik, Till Orla Klatte, Björn Busse, Michael Hahn, Johannes Maria Rueger, Martin Rupprecht
      Background The use of beta-tricalciumphospate (ß-TCP, Cerasorb®) ceramics as an alternative for autologous bone-grafting has been outlined previously, however with no study focusing on both clinical and histological outcomes of ß-TCP application in patients with multi-fragment tibial plateau fractures. The aim of this study was to analyze the long-term results of ß-TCP in patients with tibial plateau fractures. Methods 52 patients were included in this study. All patients underwent open surgery with ß-TCP block or granulate application. After a mean follow-up of 36months (14–64months), the patients were reviewed. Radiography and computed-tomography were performed, while the Rasmussen score was obtained for clinical outcome. Furthermore, seven patients underwent biopsy during hardware removal, which was subsequently analyzed by histology and backscattered electron microscopy (BSEM). Results An excellent reduction with two millimeters or less of residual incongruity was achieved in 83% of the patients. At follow-up, no further changes occurred and no nonunions were observed. Functional outcome was good to excellent in 82%. Four patients underwent revision surgery due to reasons unrelated to the bone substitute material. Histologic analyses indicated that new bone was built around the ß-TCP-grafts, however a complete resorption of ß-TCP was not observed. Discussion ß-TCP combined with internal fixation represents an effective and safe treatment of tibial plateau depression fractures with good functional recovery. While its osteoconductivity seems to be successful, the biological degradation and replacement of ß-TCP is less pronounced in humans than previous animal studies have indicated.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.06.010
  • Oxidized zirconium versus cobalt–chromium against the native patella in
           total knee arthroplasty: Patellofemoral outcomes
    • Authors: Fabrizio Matassi; Tommaso Paoli; Roberto Civinini; Christian Carulli; Massimo Innocenti
      Pages: 1160 - 1165
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Fabrizio Matassi, Tommaso Paoli, Roberto Civinini, Christian Carulli, Massimo Innocenti
      Background Oxidized zirconium (OxZr) has demonstrated excellent mechanical properties in vitro when used against articular cartilage; less coefficient of friction and less chondral damage have been found when compared with cobalt–chromium (CoCr) implants. However, controversy exists as to whether implants with a zirconium femoral component articulate safely with a native patella in total knee arthroplasty (TKA). To answer this question, the clinical and radiographic results were analysed from a group of patients who underwent a TKA with patella retention; the OxZr versus CoCr femoral components were compared. Methods The present study prospectively evaluated 83 knees of 74 patients from 2009 to 2010. Each patient was evaluated clinically (visual analogue scale, Knee Society score, patellar score) and radiographically (long leg standing radiograph, anterior–posterior and latero-lateral projections, axial view of the patella) pre-operatively and postoperatively with a mean follow-up of 4.47years. The patellar tilt and shift, and progression of patellofemoral osteoarthritis were calculated with the axial view. Results There were no patient reported adverse reactions and none of the evaluated prostheses failed. Both the clinical and radiographic evaluations showed no statistically significant between-group differences. Conclusion No adverse events were observed clinically or radiologically. These results justify pursuing the use of oxidized zirconium as an alternative bearing surface for a femoral component associated with patellar retention in TKA.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.04.012
  • 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
      Pages: 1166 - 1174
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      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: 2017-09-27T07:44:24Z
      DOI: 10.1016/j.knee.2017.05.010
  • Fatal pulmonary embolism following elective total knee replacement using
           aspirin in multi-modal prophylaxis — A 12year study
    • Authors: C. Quah; E. Bayley; N. Bhamber; P. Howard
      Pages: 1187 - 1190
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): C. Quah, E. Bayley, N. Bhamber, P. Howard
      Background The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital. Methods We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results. Results The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE’s occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%). Conclusions Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.05.021
  • Implications of the getting it right first time initiative for regional
           knee arthroplasty services
    • Authors: Richard Barksfield; James Murray; James Robinson; Andrew Porteous
      Pages: 1191 - 1197
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Richard Barksfield, James Murray, James Robinson, Andrew Porteous
      Study aim The aim of this case study of regional orthopaedic practice was to estimate the potential impact of the GIRFT recommendations (iGIRFT) of minimum unit and surgeon specific volumes to orthopaedic units within the Severn Region, UK. Method Practice profiles for surgeons and units were generated using the UK National Joint Registry Surgeon and Hospital Profile Database. Minimum volume thresholds were set at 13 procedures/year for surgeons and 30 procedures/year for units. Results Five thousand five hundred seventeen knee arthroplasty procedures were recorded within the Severn Region between 1st of January and 31st December 2012 and these were performed by 94 surgeons in 18units. During this time, 4232 (76.7%) primary TKR, 751 (13.6%) primary UKR, 97 (1.7%) primary PFJR and 437 (7.9%) revision TKR were performed. Median surgeon volumes were 33 (range two to 180) for primary TKR, ten (range 2 to 64) for UKR, two (range two to 41) for PFJR and five (range two to 57) for Revision TKR. Amongst 48 surgeons performing UKR, 26 (54%) performed less than 13 procedures per year accounting for 108 (14%) procedures. Amongst 20 surgeons performing PFJR, 19 (95%) performed <13/year, accounting for 56 (58%) of cases. Fifty surgeons performed revision TKR with 37 (74%) performing <13 revisions per annum, accounting for 151 (35%) procedures. Amongst 16units performing UKR, eight (50%) performed <30/year, accounting for 16% overall. Revision TKR was performed in 15units whilst eight (53%) performed <30/year, accounting for 62 (15%) cases. Conclusion We have hypothesised the impact of implementing minimum unit and surgeon volume thresholds for the organisation of regional arthroplasty services. Our analysis suggests that whilst these effects may be considerable, they may be mitigated by local rationalisation to achieve an appropriate caseload mix.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.05.020
  • 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
      Pages: 1198 - 1205
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      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: 2017-09-27T07:44:24Z
      DOI: 10.1016/j.knee.2017.06.005
  • Combined intravenous, topical and oral tranexamic acid administration in
           total knee replacement: Evaluation of safety in patients with previous
           thromboembolism and effect on hemoglobin level and transfusion rate
    • Authors: Joris A. Jansen; Joost R.C. Lameijer; Barbara A.M. Snoeker
      Pages: 1206 - 1212
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Joris A. Jansen, Joost R.C. Lameijer, Barbara A.M. Snoeker
      Background The aims of this study were to investigate the safety of combined intravenous, oral and topical tranexamic acid (TXA) in primary total knee replacement. We assessed dose-related efficacy on hemoglobin level, transfusion, length of stay and thromboembolic complications. In addition, TXA safety in patients with previous history of thromboembolism >12months ago was monitored specifically. Methods From January 2013 until January 2016, 922 patients were included who received TXA after primary total knee replacement. Patients without TXA administration or with thromboembolic events <12months ago were excluded. TXA dosage groups were divided into ≤10mg/kg, >10–25mg/kg and >25–50mg/kg. Results Between the three TXA groups no significant difference was found in thromboembolic complications (deep venous thrombosis (DVT) and pulmonary embolism (PE)), wound leakage and transfusion rate. For patients with DVT or PE in their history >12months ago specifically, no more complications were noted in higher-TXA-dosage groups compared to the low-dosage group. Length of stay was shorter in the highest-TXA-dosage group compared with lower-dosage groups (median two vs three days). With high TXA dose a smaller difference between pre- and postoperative Hb was found: the >25–50mg/kg TXA group had a 0.419mmol/l smaller decrease in postoperative hemoglobin compared to the lowest-dosage group (P <0.05). Conclusion Combined intravenous, oral and topical TXA is effective in knee replacement and can safely be given to patients with a thromboembolic history >12months ago. High dosage (>25–50mg/kg) TXA resulted in the smallest decrease in postoperative hemoglobin.

      PubDate: 2017-09-27T07:44:24Z
      DOI: 10.1016/j.knee.2017.07.004
  • Two-stage knee arthrodesis with a modular intramedullary nail due to
           septic failure of revision total knee arthroplasty with extensor mechanism
    • Authors: Max J. Friedrich; Jan Schmolders; Matthias D. Wimmer; Andreas C. Strauss; Milena M. Ploeger; Dieter C. Wirtz; Sascha Gravius; Thomas M. Randau
      Pages: 1240 - 1246
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Max J. Friedrich, Jan Schmolders, Matthias D. Wimmer, Andreas C. Strauss, Milena M. Ploeger, Dieter C. Wirtz, Sascha Gravius, Thomas M. Randau
      Background Periprosthetic joint infection is a serious complication and reconstruction after failed revision total knee arthroplasty with significant bone loss and compromised soft-tissues can be challenging. Objective of this study was to assess clinical and functional results, implant survival and infection recurrence rates in patients treated with two-stage arthrodesis after failed revision TKA with extensor mechanism deficiencies due to PJI, and to identify the factors that affect outcomes after surgery. Methods Thirty seven patients with PJI treated within a two-stage exchange and reimplantation of an arthrodesis nail between 2008 and 2014 were included. Systemic and local risk factors were graded preoperatively according to McPherson et al. All patients were treated according to a structured treatment algorithm. Clinical and functional evaluation was performed using the Oxford Knee Score and the Visual Analogue Scale. Results Thirty two of 37 patients (86.5%) were graded as free of infection. Five patients (13.5%) had recurrent infection after arthrodesis with the need of revision surgery. Mean leg-length discrepancy was 2.2cm. The mean VAS for pain was three, the mean Oxford Knee Score was 38±9. Total implant survival at a 74month follow-up was 74.3% (95% CI: 45.4 to 91.1%), as determined by Kaplan–Meier survival curves. Local McPherson Score, as well as number of revisions was found to be of significant influence to the survival rate. Conclusions Septic failure of revision knee arthroplasty can be effectively treated with two-stage arthrodesis using a modular intramedullary nail, providing a stable and painless limb with satisfactory functional results and acceptable infection eradication rates.

      PubDate: 2017-09-27T07:44:24Z
      DOI: 10.1016/j.knee.2017.05.019
  • Objective quantification of trochlear dysplasia: Assessment of the
           difference in morphology between control and chronic patellofemoral
           instability patients
    • Authors: Andreas Voss; Sangmin Ryan Shin; Akira M. Murakami; Mark P. Cote; Andrea Achtnich; Elmar Herbst; Anthony A. Schepsis; Cory Edgar
      Pages: 1247 - 1255
      Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5
      Author(s): Andreas Voss, Sangmin Ryan Shin, Akira M. Murakami, Mark P. Cote, Andrea Achtnich, Elmar Herbst, Anthony A. Schepsis, Cory Edgar
      Background Trochlear dysplasia is an important risk factor associated with patellofemoral instability, but it remains difficult to classify with consistency. Currently there is no objective way to quantify the dysplasia. The purpose of this study is to define and quantify objectively the trochlear morphology by volume and length via computed tomography (CT). Methods One-hundred control patients (136 knees) were retrospectively reviewed and compared to 36 consecutive patients (72 knees) who were treated surgically for recurrent patellar instability and known trochlear dysplasia based on a lateral radiograph. Trochlear morphology was analyzed from a pre-operative CT and data presented as trochlear sulcus volume trochlear length. To determine where along the trochlear length dysplasia is most variable, the trochlear length was radiographically divided into thirds, volume was quantified along that section and compared to control trochlear. Results A significant difference in trochlear morphology exists between cohorts, volume (1.98 vs 3.77cm3) and length (31.97 vs 34.66mm) (p<0.05). However, there appears to be a gender based difference in trochlea morphology. The trochlea volumetric analysis between the female cohorts (L: 2.02cm3 vs. 2.94cm3, R: 1.95cm3 vs. 2.93cm3) demonstrated significantly less volume in instability patients (p<0.001). The proximal third of the trochlear contributed the majority of dysplasia difference determined by comparing mean trochlear volume, 95% of the difference. This difference decreased in distal sections, 53% and 32% respectively. Conclusion This reproducible technique can be used to quantify the trochlea morphology, in order to describe the severity of a dysplasia.

      PubDate: 2017-09-15T06:24:34Z
      DOI: 10.1016/j.knee.2017.05.024
  • Influence of knee flexion angle and transverse drill angle on creation of
           femoral tunnels in double-bundle anterior cruciate ligament reconstruction
           using the transportal technique: Three-dimensional computed tomography
           simulation analysis
    • Authors: Chong Hyuk Choi; Sung-Jae Kim; Yong-Min Chun; Sung-Hwan Kim; Su-Keon Lee; Nam-Kyu Eom; Min Jung
      Abstract: Publication date: Available online 1 October 2017
      Source:The Knee
      Author(s): Chong Hyuk Choi, Sung-Jae Kim, Yong-Min Chun, Sung-Hwan Kim, Su-Keon Lee, Nam-Kyu Eom, Min Jung
      Background The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Methods Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Results Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Conclusion Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle.

      PubDate: 2017-10-04T08:17:48Z
      DOI: 10.1016/j.knee.2017.09.005
  • Contents List
    • Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5

      PubDate: 2017-09-15T06:24:34Z
  • British Association for Surgery of the Knee
    • Abstract: Publication date: October 2017
      Source:The Knee, Volume 24, Issue 5

      PubDate: 2017-09-15T06:24:34Z
  • Accuracy of the Precision Saw versus the Sagittal Saw during total knee
           arthroplasty: A randomised clinical trial
    • Authors: Peter Z. Feczko; Hugo J.P. Fokkenrood; Tijmen van Assen; Patrick Deckers; Pieter J. Emans; Jacobus J. Arts
      Abstract: Publication date: Available online 16 August 2017
      Source:The Knee
      Author(s): Peter Z. Feczko, Hugo J.P. Fokkenrood, Tijmen van Assen, Patrick Deckers, Pieter J. Emans, Jacobus J. Arts
      Background The aim of this study was to compare the accuracy of the oscillating tip saw system (Precision Saw=PS) with the more conventional fully oscillating blade system (Sagittal Saw=SS) during computer-assisted total knee arthroplasty (CAS-TKA). Methods A prospective, randomised, controlled trial included 58 consecutive patients who underwent primary CAS-TKA and were randomly assigned in the PS group or the SS group to compare the accuracy of both blades. The primary outcome was the difference between the intended cutting planes and the actual cutting planes in degrees (°) in two planes of both the femur and the tibia. The secondary outcome was total surgery time. Results Tibia: In the VV-plane no significant differences were registered for the mean absolute deviation (p=0.28). The PS was more accurate in the AP-plane (p=0.03). Femur: The PS showed significantly fewer mean absolute deviations in the VV-plane (p=0.03); however, the SS revealed better accuracy in the FE-plane (p=0.04). The difference in the surgery time between the groups was not statistically significant (p=0.45). Two outliers were measured using the SS, while seven outliers were detected using the PS. Conclusion The Precision Saw is not proven to be overall more accurate than the Sagittal Saw. Significantly better accuracy was shown with the PS in the two cutting planes, with the exception of one cutting plane that favoured the SS. Greater number of outliers were found using the PS. Level of evidence: II

      PubDate: 2017-08-25T17:27:04Z
      DOI: 10.1016/j.knee.2017.07.018
  • Clinical and arthroscopic outcome of single bundle anterior cruciate
           ligament reconstruction: Comparison of remnant preservation versus
           conventional technique
    • Authors: Sungwook Choi; Myung-Ku Kim; Yong Suk Kwon; Hyunseong Kang
      Abstract: Publication date: Available online 14 August 2017
      Source:The Knee
      Author(s): Sungwook Choi, Myung-Ku Kim, Yong Suk Kwon, Hyunseong Kang
      Background The purpose of this study was to compare the clinical outcomes and second-look arthroscopic findings of remnant preservation technique with those of conventional anterior cruciate ligament (ACL) reconstruction in single bundle ACL reconstructions. Methods One hundred sixty two consecutive patients underwent ACL reconstruction by one surgeon, with 93 patients receiving remnant preservation technique (Group A) and 69 patients receiving conventional ACL reconstruction (Group B). The mean follow-up was 15months. Clinical outcomes were assessed using Lysholm scores and the International Knee Documentation Committee form (IKDC form) evaluation. Post-operative knee stability was evaluated through manual knee laxity evaluation, pivot-shift test, and a Telos device. Results Differences in post-operative stability (manual knee laxity, pivot shift test and Telos device) were not significant between the groups (p=0.681, p=0.610, p=0.696). And also no significant differences were noted with respect to the IKDC form and the latest Lysholm scores. But in the second-look arthroscopic findings, synovial coverage was confirmed to be excellent in 36% (22/61) of Group A patients and 23% (7/30) of Group B patients. Conclusions ACL reconstruction with both techniques was found to result in acceptable stability, clinical outcomes and second-look arthroscopic findings. With regard to synovial coverage, the remnant reservation techniques were found to be superior to conventional ACL reconstruction. Level of evidence Level III, retrospective comparative study.

      PubDate: 2017-08-25T17:27:04Z
      DOI: 10.1016/j.knee.2017.05.012
  • 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
    • 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
    • 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
  • 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
  • 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
    • 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
    • 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
    • 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
School of Mathematical and Computer Sciences
Heriot-Watt University
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