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Journal Cover The Knee
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   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0968-0160
     Published by Elsevier Homepage  [2566 journals]   [SJR: 0.923]   [H-I: 38]
  • Primary diffuse large B-cell lymphoma associated with chronic
           osteomyelitis of the knee
    • Abstract: Publication date: Available online 8 September 2014
      Source:The Knee
      Author(s): Alfredo E. Romero-Rojas , Julio A. Diaz-Perez , Sharat Raju , Oscar Messa-Botero , Andres Prieto-Bletan , Felipe Criollo-Palacios
      Diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation is a recently adopted category of DLBCL, which describes an aggressive B-cell lymphoma raised in the setting of non-immune chronic inflammation. Primary presentation of this subtype of DLBCL in bone is extremely rare. Here, we present the case of a 27year old woman with DLBCL of the right distal femur, identified after a three-year history of chronic osteomyelitis. In this report, we describe the clinical and histopathologic features of this unusual presentation of DLBCL and discuss aspects relevant to diagnosis and treatment of this entity.


      PubDate: 2014-09-13T04:15:38Z
       
  • Gender optimized patellar component designs are needed to better match
           female patellar anatomy
    • Abstract: Publication date: Available online 8 September 2014
      Source:The Knee
      Author(s): Henry D. Clarke , Mark J. Spangehl
      Background Avoidance of both over-resection of the native patella, and over-stuffing of the patello-femoral joint are advocated to reduce the risk of patellar complications following patellar resurfacing. Female gender, due to thinner native patella, and use of patellar prostheses from one specific manufacturer that were thicker for comparable diameters than the patellar prostheses from a second manufacturer were hypothesized to be risk factors for these undesirable technical outcomes. Methods A retrospective review was undertaken of 803 consecutive knee replacements, performed by one surgeon, during which the same patellar resurfacing technique had been used, but with two different patellar implant designs. Results Female gender, and use of one specific design of patella prostheses were associated with both increased risk of patellar over resection to ≤13mm residual patellar thickness, and creation of a patella construct that was thicker than the native patella (p<0.001). Conclusions Patellar prostheses design can contribute to compromises in surgical technique during patellar resurfacing in TKA in female patients with thinner patellae. Modifications to current patellar prosthesis dimensions may be considered to allow surgeons to more accurately resurface the thinner, native female patella. Level of Evidence III


      PubDate: 2014-09-13T04:15:38Z
       
  • The limited use of a tourniquet during total knee arthroplasty: A
           randomized controlled trial
    • Abstract: Publication date: Available online 9 September 2014
      Source:The Knee
      Author(s): Yu Fan , Jin Jin , Zhijian Sun , Wenjing Li , Jin Lin , Xisheng Weng , Guixing Qiu
      Background Total knee arthroplasty (TKA) is commonly performed using a tourniquet. However, some studies have reported that several complications were associated with the use of a tourniquet in TKA. In this study we investigate whether the limited use of a tourniquet in TKA would reduce complications and facilitate postoperative recovery. Methods Sixty patients were randomly divided into two groups (30 cases/group): group A using the tourniquet throughout the surgical procedure, and group B using the tourniquet starting from the cementation to the completion of the procedure. Operation time, total measured blood loss, and incidence of complications were all recorded. Results There was no significant difference in operation time, total measured blood loss, and hemoglobin concentration between the two groups. Incidence of postoperative complications in group B was significantly decreased in comparison to that in group A. The limb circumference at 10cm above the superior patellar pole or below the inferior patellar pole and the pain score in group B were significantly decreased compared with that in group A at any time point. Range of motion in group B was significantly increased at three and 5days postoperatively in comparison to that in group A. Conclusions The limited use of a tourniquet in TKA provides the benefit of decreased limb swelling and knee joint pain while not compromising the operation time or blood loss and recovery. Level of evidence Level I (Therapeutic). Trial registration number NCT02102581.


      PubDate: 2014-09-13T04:15:38Z
       
  • Radiographic evaluation of factors affecting bearing dislocation in the
           domed lateral Oxford unicompartmental knee replacement
    • Abstract: Publication date: Available online 10 September 2014
      Source:The Knee
      Author(s): A. Gulati , S. Weston-Simons , D. Evans , C. Jenkins , H. Gray , C.A.F. Dodd , H. Pandit , D.W. Murray
      Background The rate of bearing dislocation with the domed lateral Oxford Unicompartmental Knee Replacement (OUKR) in different series varies from 1% to 6% suggesting that dislocation is influenced by surgical technique. The aim of this study was to identify surgical factors associated with dislocation. Methods Aligned post-operative antero-posterior knee radiographs of seven knees that had dislocated and 87 control knees were compared. Component alignment and position and the alignment of the knee were assessed. All bearing dislocations occurred medially over the tibial wall. Results Knees that dislocated tended to be overcorrected: Compared with those that did not dislocate, they were in 2° less valgus (p=0.019) and the tibial components were positioned 2mm more proximal (p<0.01). Although the relative position of the centre of the femoral component and the tibial component was the same (p=0.8), in the dislocating group the gap between the edge of the femoral component and the top of the wall in flexion was 3mm greater (p=0.019) suggesting that the components were internally rotated. Conclusions To minimise the risk of dislocation it is recommended that the knee should not be overstuffed. This is best achieved by selecting the bearing thickness that just tightens the ligaments in full extension, and re-cutting the tibia if necessary. In addition to minimise the gap between the femoral and tibial components through which the bearing dislocates, the femoral component should be implanted in neutral rotation and should not be internally rotated. Level of evidence Level IV


      PubDate: 2014-09-13T04:15:38Z
       
  • Outcome of revision total knee arthroplasty with the use of trabecular
           metal cone for reconstruction of severe bone loss at the proximal tibia
    • Abstract: Publication date: Available online 10 September 2014
      Source:The Knee
      Author(s): Claus L. Jensen , Nikolaj Winther , Henrik M. Schrøder , Michael M. Petersen
      Background The relative effectiveness of different methods for reconstructing large bone loss at the proximal tibia in revision total knee arthroplasty (rTKA) has not been established. The aim of this study was to evaluate the clinical and radiological outcome after the use of trabecular metal technology (TMT) cones for the reconstruction of tibial bone loss at the time of rTKA. Methods Thirty-six patients had rTKA with the use of a TMT Cone. Bone loss was classified according to the AORI classification and 25% of the patients suffered from T3 AORI defects and 75% of the patients from T2 AORI defects. Implants used were from the NexGen® series. At follow-up, radiographs were evaluated according to the Knee Society Roentgenographic Scoring System. Knee and function score was calculated using the Knee Society Clinical Rating System. Average follow-up time was 47months (range 3–84months). Results Clinical and radiological follow-up data were available in 30 patients and missing in six patients: two died and four patients had re-revision (reinfection (n=2), aseptic loosening (n=1), and knee hyperextension (n=1)). Knee- and function scores (follow-up 43months (range 12–84months)) improved from 42 to 77 points (p<0.0005) and 19 to 63 points (p<0.0005) respectively. Twenty-seven patients (follow-up 44months (range 12–72months)) showed no signs of radiological loosening of rTKA components. Conclusion Based on our study, it was concluded that the use of TMT Cones provided an effective treatment in terms of surgical efficacy, clinical results and radiological results and was evidently at least as effective as the other options reviewed in the literature. Level of evidence IV.


      PubDate: 2014-09-13T04:15:38Z
       
  • Quadriceps/hamstrings co-activation increases early after total knee
           arthroplasty
    • Abstract: Publication date: Available online 11 September 2014
      Source:The Knee
      Author(s): Abbey C. Thomas , Dana L. Judd , Bradley S. Davidson , Donald G. Eckhoff , Jennifer E. Stevens-Lapsley
      Quadriceps and hamstrings weakness and co-activation are present following total knee arthroplasty (TKA) and may impair functional performance. How surgery and post-operative rehabilitation influence muscle activation during walking early after surgery is unclear. Purpose Examine muscle strength and activation during walking before and one and 6-months post-TKA. Methods Ten patients (n=6 female; age: 64.7±7.9years; body mass index[BMI]:29.2±2.5kg/m2) and 10 healthy adults (n=6 female; age: 60.6±7.4years; BMI: 25.5±4.0kg/m2) participated. The patients underwent bilateral quadriceps and hamstrings strength testing and assessment of quadriceps/hamstrings co-activation and on/off timing using surface electromyography during a six-minute walk test (6MW). Groups, limbs, and changes with TKA surgery were compared. Results Patients reported greater 6MW knee pain pre- versus post-TKA and compared to controls (P <0.05). Patients had weaker surgical limb hamstrings (P <0.05) and bilateral quadriceps (P <0.05) strength than controls pre- and post-TKA. Before and 1-month post-TKA, patients had side-to-side differences in quadriceps and hamstrings strength (P <0.05). Controls walked farther than patients (P <0.01). Patients demonstrated greater surgical limb co-activation pre-operatively than controls (P <0.05). Co-activation was higher bilaterally one-month post-TKA compared to controls (P <0.05). Patients turned off their quadriceps later during stance than controls before and 1-month post-TKA (P <0.05). Conclusions Muscle strength, co-activation, and timing differed between patients and controls before and early after surgery. Rehabilitation to improve strength and muscle activation seems imperative to restore proper muscle firing patterns early after surgery.


      PubDate: 2014-09-13T04:15:38Z
       
  • Radiographic outcome of limb-based versus knee-based patient specific
           guides in total knee arthroplasty
    • Abstract: Publication date: Available online 11 September 2014
      Source:The Knee
      Author(s): Catherine Crane , Kanniraj Marimuthu , Darren B. Chen , Ian A. Harris , Emma Wheatley , Samuel J. MacDessi
      Background Patient specific guides (PSG's) were developed to improve overall component alignment in total knee arthroplasty (TKA). The aim of this study was to undertake a comparative radiographic study of two commonly used PSG and determine whether the radiographic technique used to construct the PSG had a significant effect on overall alignment. Methods This prospective cohort study examined the accuracy of limb-based (n=112) versus knee-based (n=105) MR PSG in restoring the mechanical axis in three planes according to post-operative Perth CT scan protocol. Results Limb-based MR and knee-based MR PSG systems both restored overall hip–knee–ankle angle (HKAA), femoral coronal alignment, tibial coronal alignment, femoral sagittal alignment, tibial sagittal alignment and femoral rotation alignment to within 3° of a neutral mechanical axis with similar precision (91.1% vs. 86.7% p=0.30, 97.3% vs. 96.2% p=0.63, 97.3% vs. 97.1% p=0.94, 94.6% vs. 89.4% p=0.16, 90.2% vs. 81.0% p=0.05, 91.1% vs. 86.7% p=0.30, respectively). However, when the secondary outcome measure of alignment within 2° was assessed, limb-based MR PSG restored HKAA, femoral coronal and tibial sagittal alignment with greater precision than knee-based MR PSG (73.2% vs. 64.8% p=0.016, 93.8% vs. 80.8% p=0.004 and 82.1% vs. 62.9% p=0.001, respectively). Conclusions The findings of this study recommend the use of limb-based MR PSG for improved precision in the restoration of neutral mechanical alignment over knee-based MR PSG in TKA. Level of Evidence Therapeutic level III


      PubDate: 2014-09-13T04:15:38Z
       
  • High protracted 99mTc-HDP uptake in synthetic bone implants — A
           potentially misleading incidental finding on bone scintigraphy
    • Abstract: Publication date: Available online 12 September 2014
      Source:The Knee
      Author(s): Claire Tabouret-Viaud , Ismini Mainta , Sana Boudabbous , Gaël Amzalag , Osman Ratib , Olivier Rager , Frédéric Paycha
      We report the case of a 56-year-old male with bilateral total knee prostheses suffering from bilateral knee pain mainly on the right side and referred for bone scintigraphy. The medical history of the patient revealed an opening wedge high tibial osteotomy performed nine years earlier, with insertion of two blocks of ceramic made of hydroxyapatite and tricalcium phosphate in a wedge configuration as synthetic bone substitutes. The porous structure of these implants is analogous to the architecture of cancellous bone and permits fibrovascular and bone ingrowth, promoting the healing process. Planar scintigraphy and SPECT/CT showed an intense uptake within those implants in the early phase as well as in the late phase of the bone scan. It also showed bilateral patellofemoral arthritis. A 99mTc-labeled antigranulocyte antibody scintigraphy was negative for infection or inflammation. Bilateral patellar resurfacing led to complete symptom regression, confirmed at 10months follow-up. To the best of our knowledge, this scintigraphic pattern with such a high tracer uptake reflecting bone substitute osteointegration has not yet been published. This should be considered in patients with such bone replacement materials that are increasingly used, in order to avoid false diagnosis of inflammation or infection.


      PubDate: 2014-09-13T04:15:38Z
       
  • Inferior outcomes of total knee replacement in early radiological stages
           of osteoarthritis
    • Abstract: Publication date: Available online 6 September 2014
      Source:The Knee
      Author(s): C.N. Peck , J. Childs , G.J. McLauchlan
      Background Total knee replacement (TKR) for osteoarthritis (OA) is a common and successful operation; the severity of radiographic changes plays a key role as to when it should be performed. This study investigates whether an early radiological grade of OA has an adverse effect on the outcome of TKR in patients with arthroscopically confirmed OA. Methods Between January 2006 and January 2011 data was collected prospectively on all patients undergoing a primary TKR for OA. We included all patients with a Kellgren–Lawrence score of two or less on their pre-operative radiograph who had had an arthroscopy to confirm significant OA. Our primary outcomes were the Oxford Knee Score (OKS) and a satisfaction rating. Results Over the study period 1708 primary TKRs were performed in 1381 patients. We identified 44 TKRs in 43 patients with a Kellgren–Lawrence score of two or less on their pre-operative radiograph. In this group the mean age was 63years, 66% were female and the mean BMI was 31.7kg/m2. At a mean follow-up of 37months the mean OKS was only 30 points compared to 36 in all TKRs performed over the same period (p =0.0004). Only 68% were either satisfied or very satisfied. Eight knees (18%) underwent further surgery, three (6.8%) of which were revision procedures, compared to a revision rate of 1.6% in all patients. Conclusion The outcomes of TKR in patients with early radiological changes of OA are inferior to those with significant radiological changes and should be performed with caution. Level of evidence Level IV case-series.


      PubDate: 2014-09-08T03:05:11Z
       
  • Effect of medial–lateral malpositioning of the femoral component in
           total knee arthroplasty on anterior knee pain at greater than 8years of
           follow-up
    • Abstract: Publication date: Available online 4 September 2014
      Source:The Knee
      Author(s): S.A.W. van de Groes , S. Koëter , M. de Waal Malefijt , N. Verdonschot
      Background The trochlea is often medialized after total knee arthroplasty (TKA) resulting in abnormal patellar tracking, which may lead to anterior knee pain. However, due to the difference in shape of the natural trochlea and the patellar groove of the femoral component, a medialization of the femoral component of 5mm results in an equal patellar position at 0–30° of flexion. We tested the hypothesis that more medialization of the trochlea results in a higher VAS pain score and lower Kujala anterior knee pain score at midterm follow-up. Methods During surgery a special instrument was used to measure the mediolateral position of the natural trochlea and the prosthetic groove in 61 patients between 2004 and 2005. Patient reported outcome measures were used to investigate the clinical results (NRS-pain, NRS-satisfaction, KOOS-PS and Kujala knee score). Results In total 40 patients were included. The mean follow-up was 8.8years. A medialization of ≥5mm resulted in a significantly lower NRS-pain (0.2 vs. 1.4; p=0.004) and higher NRS-satisfaction (9.6 vs. 8.2; p=0.045). Overall clinical results were good; KOOS-PS was 33.9 and Kujala knee score was 72.1. Conclusions The present study showed that a more medial position may result in a better postoperative outcome, which can probably be explained by the non-physiological lateral orientation of the trochlear groove in TKA designs. Level of evidence: Level III


      PubDate: 2014-09-08T03:05:11Z
       
  • Altered dynamic foot kinematics in people with medial knee osteoarthritis
           during walking: A cross-sectional study
    • Abstract: Publication date: Available online 4 September 2014
      Source:The Knee
      Author(s): John Arnold , Shylie Mackintosh , Sara Jones , Dominic Thewlis
      Background Footwear and insoles are used to reduce knee load in people with medial knee osteoarthritis (OA), despite a limited understanding of foot function in this group. The aim of this study was to investigate the differences in foot kinematics between adults with and without medial knee OA during barefoot walking. Methods Foot kinematics were measured during walking in 30 adults; 15 with medial knee OA (mean age was 67.0 with a standard deviation (SD) of 8.9years; height was 1.66 with SD of 0.13m; body mass was 84.2 with SD of 15.8kg; BMI was 30.7 with SD of 6.2 kg/m2; K–L grade 3: 5, grade 4: 10) and 15 aged and gender matched control participants with 12 motion analysis cameras using the IOR multi-segment foot model. Motion of the knee joint, hindfoot, midfoot, forefoot and hallux were compared between groups using clustered linear regression. Results The knee OA group displayed reduced coronal plane range of motion of the midfoot (mean 3.8° vs. 5.4°, effect size=1.1, p=0.023), indicating reduced midfoot mobility. There was also a reduced sagittal plane range of motion at the hallux in the knee OA group compared to the control group (mean 29.6° vs. 36.3°, effect size=1.2, p=0.008). No statistically significant differences in hindfoot or forefoot motion were observed. Conclusions People with medial knee OA display altered foot function compared to healthy controls. As foot and knee function are related, it is possible that altered foot function in people with knee OA may influence the effects of footwear and insoles.


      PubDate: 2014-09-08T03:05:11Z
       
  • Comparison of MRI- and CT-based patient-specific guides for total knee
           arthroplasty
    • Abstract: Publication date: Available online 6 September 2014
      Source:The Knee
      Author(s): Shigeki Asada , Shigeshi Mori , Tetsunao Matsushita , Koichi Nakagawa , Ichiroh Tsukamoto , Masao Akagi
      Background The patient-specific guide for total knee arthroplasty (TKA) is created from the data provided by magnetic resonance imaging (MRI) or computed tomography (CT) scans. It remains unknown which imaging technology is suitable for the patient-specific guide. The purpose of this study was to compare the accuracy of implant positioning and operative times between the two types of patient-specific guides for TKA. Methods Forty arthritic knees were divided into two treatment groups using MRI-based (PS-MRI group) or CT-based (PS-CT group) patient-specific guides in this prospective, comparative study. The guide in the PS-MRI group had a cutting slot, whereas that in the PS-CT group only had a pin locator. The operative times were compared between the two groups. The angular error and number of outliers (deviations >3°) of the implant position using pre- and postoperative CT were investigated in both groups. Results The mean operative time was significantly shorter in the PS-MRI group (109.2±16.5min) than in the PS-CT group (129.5±19.4min) (p <0.001). There were no significant differences in the accuracy of the implant position regarding the coronal, sagittal, and axial planes between the groups (p >0.05). Conclusions To reduce the operative time, guides with additional functions, such as cutting and positioning, should be used. Both CT- and MRI-based-guides would result in the same accuracy in three planes but high inaccuracy in the sagittal plane. The use of patient-specific guide based on MRI might not be cost-effective. Level of evidence: level 2.


      PubDate: 2014-09-08T03:05:11Z
       
  • Anterior cruciate ligament reconstruction in patients over 50years of age
    • Abstract: Publication date: Available online 28 August 2014
      Source:The Knee
      Author(s): David Figueroa , Francisco Figueroa , Rafael Calvo , Alex Vaisman , Gonzalo Espinoza , Federico Gili
      Purpose To describe the clinical outcomes of patients over 50years of age with following anterior cruciate ligament (ACL)reconstruction for acute rupture. Methods A prospective series of patients over the age of 50years with a diagnosis of ACL rupture who underwent ACL reconstruction was examined. Lysholm and International Knee Documenting Committee (IKDC) subjective scores were assessed preoperatively and at the final follow-up. All associated injuries were documented, and complications were reported. The patients' satisfaction and return to sports were documented. The statistical analyses were preformed with Student's t-tests for independent samples. Results Fifty patients with a mean age of 52.12years (50–64) and a mean follow-up period of 53.17months (36–68) exhibited a mean postoperative Lysholm score of 93.7 (60–100) and IKDC score of 90.96 (57.5–100). Associated injuries occurred in 90% (45) of the patients and included the following: 76% (38) meniscal tears and 36% (18) osteochondral lesions. Complications occurred in 6% (3) of the patients and included the following: 4% (2) ACL re-ruptures and 2% (1) infections. Among all patients, 88% (44) returned to pre-injury sports levels, and 96% (48) were satisfied. Conclusions For patients above the age of 50years, ACL reconstruction appears to be a safe procedure with good to excellent results that are comparable to those for younger patients, and the possibility for returning to pre-injury sports levels for these patients is high.


      PubDate: 2014-09-04T01:39:12Z
       
  • When the tendon autograft drops accidently on the floor: A study about
           bacterial contamination and antiseptic efficacy
    • Abstract: Publication date: Available online 11 August 2014
      Source:The Knee
      Author(s): O. Barbier , J. Danis , G. Versier , D. Ollat
      Background Inadvertent contamination of the autograft could occur during ACL reconstruction if the autograft drops on the floor during surgery. A study was undertaken to determine the incidence of contamination when a graft dropped on the operating room floor and the efficacy of antimicrobial solutions to decontaminate it. Methods Samples from 25 patients undergoing ACL reconstruction with a hamstring tendon were sectioned and dropped onto the floor. Cultures were taken after immersion in an antiseptic solutions (a chlorhexidine gluconate solution (group 1), a povidone-iodine solution (group 2), a sodium-hypochlorite solution (group 3)). A fourth piece (group 0) was cultured without being exposed to any solution. Cultures of a floor swab were taken at the same time. Results The floor swab cultures were positive in 96% of cases. The rate of contamination was 40% in group 0, 8% in group 1, 4% in group 2, and 16% in group 3. There was a significant difference between groups 1–2 and 0 (p<0,05) but not between group 3 and 0. Conclusion Immersing a graft dropped onto the floor during surgery into in a chlorhexidine gluconate solution or povidone-iodine solution significantly reduces contamination of the graft. Soaking of the hamstring autograft in one of theses solutions is recommended in case of inadvertent contamination. Clinical relevance laboratory investigation (level 2)


      PubDate: 2014-08-14T23:35:12Z
       
  • MPFL Reconstruction using a Quadriceps tendon graft Part 1: Biomechanical
           Properties of Quadriceps Tendon MPFL Reconstruction in Comparison to the
           Intact MPFL. A Human Cadaveric Study
    • Abstract: Publication date: Available online 7 August 2014
      Source:The Knee
      Author(s): Mirco Herbort , Christian Hoser , Christoph Domnick , Michael J. Raschke , Simon Lenschow , Andre Weimann , Clemens Kösters , Christian Fink
      Background The aim of this study was to analyze the structural properties of the original MPFL and to compare it to a MPFL-reconstruction-technique using a strip of quadriceps tendon. Methods In 13 human cadaver knees the MPFLs have been dissected protecting their insertion at the patellar border. The MPFL has been loaded to failure after preconditioning with 10cycles in a uniaxial testing machine evaluating stiffness, yield load and maximum load to failure. In the second part Quadriceps-MPFL-reconstruction has been performed and tested in a uniaxial testing machine. Following preconditioning, the constructs were cyclically loaded 1000 times between 5 and 50N measuring the maximum elongation. After cyclic testing, the constructs have been loaded to failure measuring stiffness, yield load and maximum load. For statistical analysis a RM one-way ANOVA for multiple comparisons has been used. The significance was set at p<0.05. Results During the load to failure tests of the original MPFL the following results have been measured: Stiffness 29.4N/mm(+9.8), yield load 167.8N(+80) and maximum load to failure 190.7N(+82.8). The results in the QT-technique group: Maximum elongation after 1000cycles 2.1mm(+0.8), stiffness 33.6N/mm(+6.8), yield load 147.1N(+65.1) and maximum load to failure 205N(+77.8). There were no significant differences in all tested parameters. Conclusion In a human cadaveric model using a strip of quadriceps-tendon 10mm wide and 3mm deep, the biomechanical properties match those of the original MPFL when tested as a reconstruction. Clinical relevance The tested QT-technique shows sufficient primary stability with comparable biomechanical parameters to the intact MPFL.


      PubDate: 2014-08-09T23:17:43Z
       
  • In Vivo Kinematic Analysis of Posterior-Stabilized Total Knee Arthroplasty
           for the Valgus Knee Operated by Gap-Balancing Technique
    • Abstract: Publication date: Available online 4 August 2014
      Source:The Knee
      Author(s): Koji Suzuki , Noriyuki Hara , Susumu Mikami , Tetsuya Tomita , Keiji Iwamoto , Takaharu Yamazaki , Kazuomi Sugamoto , Shigeo Matsuno
      Background Most in vivo kinematic studies of total knee arthroplasty (TKA) report on varus knee. The objective of the present study was to evaluate in vivo kinematics of a posterior-stabilized fixed-bearing TKA operated on valgus knee during knee bending in weight-bearing (WB) and non-weight-bearing (NWB). Methods A total of sixteen valgus knees in 12 cases that underwent TKA with Scorpio NRG PS knee prosthesis and that were operated on using gap balancing technique were evaluated. We evaluated the in vivo kinematics of the knee using fluoroscopy and femorotibial translation relative to the tibial tray using a 2-dimentional to 3-dimensional registration technique. Results The average flexion angle was 111.3°±7.5° in WB and 114.9°±8.4° in NWB. The femoral component demonstrated a mean external rotation of 5.9°±5.8° in WB and 7.4°±5.2° in NWB. In WB and NWB, the femoral component showed medial pivot pattern from 0° to midflexion and a bicondylar rollback pattern from midflexion to full flexion. Medial condyle moved similarly in WB condition and in NWB condition. Lateral condyle moved posterior at a slightly earlier angle during WB condition than during NWB condition. Conclusions We conclude that the similar kinematics after TKA can be obtained with the gap balancing technique for the preoperative valgus deformity to the kinematics of normal knee, even though the magnitude of external rotation was small. Level of evidence: IV.


      PubDate: 2014-08-05T23:13:16Z
       
  • Repair of a Radial Tear in the Posterior Horn of the Lateral Meniscus
    • Abstract: Publication date: Available online 4 August 2014
      Source:The Knee
      Author(s): Hyun-Seok Song , Tae-Yong Bae , Bum-Yong Park , Jungin Shim , Yong In
      Background Although meniscal repair using the FasT-Fix meniscal repair system has become popular, there are no studies evaluating the clinical results after repair of a radial tear in the posterior horn of the lateral meniscus (PHLM) using the FasT-Fix system. This study was undertaken to evaluate the clinical outcomes after repair of a radial tear in the PHLM using the FasT-Fix system in conjunction with anterior cruciate ligament (ACL) reconstruction. Methods Between September 2008 and August 2011, 15 radial tears in the PHLM identified during 132 consecutive ACL reconstructions were repaired using the FasT-Fix meniscal repair system. We classified the radial tears into 3 types according to the tear patterns; simple radial tear, complex radial tear, and radial tear involving the popliteal hiatus. Postoperative evaluation was performed using the Lysholm knee score and Tegner activity level. Second-look arthroscopy was performed in all cases. Results The mean follow-up period was 24months. None of the patients had a history of recurrent effusion, joint line tenderness or a positive McMurray test. The meniscal repair was considered to have a 100% clinical success rate. At the final follow-up, the Lysholm knee score and Tegner activity level were significantly improved compared to the preoperative values. On second-look arthroscopy, repair of radial tears in the PHLM in conjunction with ACL reconstruction using the FasT-Fix device resulted in complete or partial healing in 86.6% of cases. Conclusion Clinical results after meniscal repair of a radial tear in the PHLM by using the FasT-Fix system were satisfactory. Level of evidence Case series, Level IV.


      PubDate: 2014-08-05T23:13:16Z
       
  • Lower Extremity Neuromuscular Compensations during Instrumented Single Leg
           Hop Testing 2–10 Years Following ACL Reconstruction
    • Abstract: Publication date: Available online 31 July 2014
      Source:The Knee
      Author(s): John Nyland , Jeff Wera , Scott Klein , David N.M. Caborn
      Background This study compared lower extremity EMG activation and sagittal plane kinematics of subjects at a minimum of 2years post-successful ACL reconstruction and rehabilitation during instrumented single leg hop testing. Methods Comparisons were made based on subject responses to the following question, "compared to prior to your knee injury how capable are you now in performing sports activities"? Group 1=very capable, Group 2=capable, and Group 3=not capable. In addition to EMG (1000Hz)and kinematic (60Hz) data, subjective knee function, internal health locus of control, sports activity characteristics (intensity, frequency) pre-knee injury, and at follow-up were also compared. Results Group 3 had lower perceived knee function, decreased perceived sports intensity, and more subjects with decreased sports activity intensity by two levels compared to pre-injury values. Perceived function scores, anterior laxity measurements and grades were similar between groups. During single leg hop propulsion and landing Group 1 (very capable) had greater involved lower extremity gluteus maximus and medial hamstring activation amplitudes than Group 3 (not capable). Perceived sports capability was related to better subjective knee function, and higher perceived sports activity intensity. Conclusion Neuromuscular compensations suggesting a hip bias with increased gluteus maximus and medial hamstring activation were identified at the involved lower extremity among most subjects who perceived high perceived sports capability compared to pre-injury status. These compensations may be related to a permanent neurosensory deficit, and its influence on afferent pathway changes that influence CNS sensorimotor re-organization.


      PubDate: 2014-08-01T23:07:50Z
       
  • Effects of whole-body vibration exercise on muscular strength and power,
           functional mobility and self-reported knee function in middle-aged and
           older Japanese women with knee pain
    • Abstract: Publication date: Available online 28 July 2014
      Source:The Knee
      Author(s): Taishi Tsuji , Jieun Yoon , Tatsuya Aiba , Akihiro Kanamori , Tomohiro Okura , Kiyoji Tanaka
      Background Whole-body vibration training using vertical-vibration machines is called “acceleration training” (AT). The purpose of this study was to elucidate the effect of AT on lower-limb muscular strength and power, functional mobility and self-reported knee function in middle-aged and older Japanese women with knee pain. Methods Thirty-eight middle-aged and older Japanese women (aged 50-73 years) with knee pain were divided into two groups: (1) the AT group (n=29) engaged in AT 3 times per week for 8weeks, and (2) the control group (C group, n=9). The AT program consisted of flexibility training, strength training of mainly the quadriceps and surrounding muscles and cool-down exercises. The C group was encouraged to perform the same or similar exercises at home without vibratory stimulus. We evaluated knee strength and power, functional mobility (timed up and go: TUG) and self-reported knee function (Japanese Knee Osteoarthritis Measure: JKOM). Results No one in the AT group dropped out during the program. All JKOM categories except degree of pain improved significantly post intervention indicating improved knee function, and TUG was significantly shorter in these participants. All knee strength and power parameters except isometric knee extension peak torque improved significantly. The degree of change in JKOM total score and TUG were significantly different between the two groups. Conclusion Vibratory stimulus during an 8-week AT program can promote participation and safely improve functional mobility and self-reported knee function better than exercise without vibratory stimulus in middle-aged and older Japanese women with knee pain. Level of Evidence: level 2.


      PubDate: 2014-08-01T23:07:50Z
       
  • Medial Patellofemoral Ligament (MPFL) Reconstruction Improves Radiographic
           Measures of Patella Alta in Children
    • Abstract: Publication date: Available online 30 July 2014
      Source:The Knee
      Author(s): Peter D. Fabricant , Hannah N. Ladenhauf , Eduardo A. Salvati , Daniel W. Green
      Background Patellofemoral instability has previously been associated with patella alta. The purpose of this study was to evaluate adolescents undergoing MPFL reconstruction for standardized indices of patellar height on pre- and postoperative radiographs to determine if these radiographic parameters change after MPFL reconstruction. Methods Twenty-seven children (mean age 14.9years old) who underwent MPFL reconstruction without a distal realignment procedure were evaluated pre- and post-operatively for Insall-Salvati Ratio, Modified Insall-Salvati Ratio, and Caton-Deschamps Index by three blinded raters. Intrarater and interrater reliability was calculated for each index, and means of each were compared pre- and postoperatively to determine if MPFL reconstruction was associated with improved patellar height. Results All three indices of patellar height indicated that there was patella alta present in this cohort preoperatively. Furthermore, all three measures were significantly improved postoperatively (Paired t-tests, P<0.001 for all) to within normal childhood ranges. Interrater reliability was excellent for both the Insall-Salvati ratio (ICC=0.89) and Caton-Deschamps index (ICC=0.78), and adequate for the modified Insall-Salvati ratio (ICC=0.57); intrarater reliability was excellent for all three (ICC’s: 0.91, 0.82, 0.80 respectively). Conclusions MPFL reconstruction in children using hamstring autograft was associated with consistently improved patella height indices to within normal childhood ranges. This associated improvement of patellar height as measured on a lateral radiograph may subsequently improve patella femoral mechanics by drawing the patella deeper and more medial into the trochlear groove.


      PubDate: 2014-08-01T23:07:50Z
       
  • Synovial Fluid Differential Cell Count in Wear Debris Synovitis after
           Total Knee Replacement
    • Abstract: Publication date: Available online 28 July 2014
      Source:The Knee
      Author(s): Ran Schwarzkopf , Evan M. Carlson , Meagan E. Tibbo , Lee Josephs , Richard D. Scott
      Background Determining the cause of synovitis following total knee arthroplasty (TKA) can be challenging. The differential diagnosis includes infection, hemarthrosis, instability, crystalline disease, wear debris or idiopathic. Wear particle synovitis can mimic periprosthetic infection with symptoms of pain and effusion. Radiographs and physical exam are often inconclusive in differentiating the two. Synovial fluid analysis is routinely used in evaluating periprosthetic infections. We examined the association between synovial white blood cell count and differentials, and polyethylene wear and osteolysis, to see if fluid analysis can aid in establishing the diagnosis of wear particle synovitis. Methods A cell count and differential was obtained from synovial fluid samples from 54 TKAs undergoing revision for aseptic failure. Explanted polyethylene inserts were analyzed for linear and volumetric wear, oxidation (ketone peak height), and damage features. Analysis was performed to assess the relationship between cell counts and polyethylene wear indicators as well as severity of intra-operative and radiographic osteolysis. Results Total and percent mononuclear (monocyte and lymphocyte) cell counts were found to be elevated in the presence of documented wear debris synovitis and an association was suggested between their levels and maximum ketone levels. Conclusion The present study implies that the differential cell count of knee fluid can help distinguish wear debris from infection as a source of synovitis following TKA and identifies the value of the mononuclear cell count as a possible tool to assess abnormal wear rates of the polyethylene insert. Further research into identifying the exact role of monocytes in the wear debris synovitis and osteolytic pathways is warranted. Level of Evidence Level II, diagnostic study.


      PubDate: 2014-08-01T23:07:50Z
       
  • Trochlear boss height measurement: A comparison of radiographs and MRI
    • Abstract: Publication date: Available online 24 July 2014
      Source:The Knee
      Author(s): J.W. MacKay , K.C. Godley , A.P. Toms , S.T. Donell
      Background A key anatomical consideration and determinant of surgical approach in trochlear dysplasia is the trochlear boss height (TBH), traditionally defined by measurements on plain x-rays (XR). Magnetic resonance (MR) imaging is increasingly used for pre-operative planning and follow-up. However, it is unclear whether measurement of TBH on XR is applicable to MR. The aim of this study was to establish the reliability of TBH measurement on MR compared to XR. Methods This study used lateral knee radiographs and MR scans of 14 knees of patients with trochlear dysplasia, six knees of non-dysplastic patients with anterior knee pain (AKP), and five knees of non-dysplastic controls with no AKP. Correlation between XR and MR measurements was assessed using Pearson correlation coefficients. Agreement between methods and observers was assessed using Bland-Altman plots with 95% limits of agreement. Intra- and inter- observer reliability was assessed using intraclass correlation coefficients (ICC). Results Bland-Altman charts showed a total width of 95% limits of agreement of 4.78mm for XR and MR subchondral bone (SB) TBH measurements, and 6.73mm for XR and MR cartilage TBH measurements. Inter-observer ICCs were 0.86 for XR, 0.62 for MR SB, and 0.53 for MR cartilage. The widths of the Bland-Altman 95% limits of agreement between observers were 4.79mm (XR), 5.04mm (MR SB) and 4.74mm (MR cartilage). Conclusion Measurement of TBH on MR is not directly interchangeable with XR. Adjustments need to be made to treatment thresholds based on XR measurement if MR is used instead.


      PubDate: 2014-07-27T22:28:39Z
       
  • Coronal Tibiofemoral Subluxation; A New Measurement Method
    • Abstract: Publication date: Available online 24 July 2014
      Source:The Knee
      Author(s): Saker Khamaisy , Hendrik A. Zuiderbaan , Ran Thein , Danyal H. Nawabi , Leo Joskowicz , Andrew D. Pearle
      Background Coronal tibiofemoral (CTF) subluxation is a common finding in knee osteoarthritis (OA) which can be related to poor pain scores and tibial spine impingement. In this study we describe a new method for measuring CTF subluxation and present validation of the method using cadaveric knees. Methods A prototype software code based on the ICP mathematical algorithm was developed to measure CTF subluxation; the code finds the rigid transformation that best aligns the articular surfaces, measures CTF subluxation and the angle between articular surfaces. For validation, three stripped fresh frozen cadaveric knee specimens were transfixed to a specially designed knee fixation device where tibiofemoral angle and CTF subluxation can be measured directly. Fluoroscopic images were obtained with the tibiofemoral joint in neutral alignment and with 5, 10 and 15 (mm) of medial and lateral subluxation. This procedure was repeated with a neutral tibiofemoral angle, 10° of varus, and 10° of valgus. All images were analyzed independently by two investigators using the prototype software. Results The interclass correlation coefficient between the two investigators for CTF subluxation and tibiofemoral angle was 0.93 and 0.99 respectively. The CTF subluxation and tibiofemoral angle measured by the software correlated to the CTF subluxation and tibiofemoral angle defined using the knee fixation device, with Pearson product moments of 0.86 and 0.94 respectively. Conclusion Our suggested prototype software is precise, repeatable and reliable at measuring CTF subluxation and tibiofemoral angle. It may prove to be a useful tool to evaluate CTF subluxation in a clinical setting.


      PubDate: 2014-07-27T22:28:39Z
       
  • Relationship of the Posterior Femoral Axis of the “Kinematically
           Aligned” Total Knee Arthroplasty to the Posterior Condylar,
           Transepicondylar, and Anteroposterior Femoral Axes
    • Abstract: Publication date: Available online 24 July 2014
      Source:The Knee
      Author(s): Andrew Park , Stephen T. Duncan , Ryan M. Nunley , James A. Keeney , Robert L. Barrack , Denis Nam
      Background A recent proposed modification in surgical technique in total knee arthroplasty (TKA) has been the introduction of the “kinematically aligned” TKA, in which the angle and level of the posterior joint line of the femoral component and joint line of the tibial component are aligned to those of the “normal,” pre-arthritic knee. The purpose of this study was to establish the relationship of the posterior femoral axis of the “kinematically aligned” total knee arthroplasty (TKA) to the traditional axes used to set femoral component rotation. Methods 114 consecutive, unselected patients with preoperative MRI images undergoing TKA were retrospectively reviewed. The transepicondylar axis (TEA), posterior condylar axis (PCA), antero-posterior axis (APA) of the trochlear groove, and posterior femoral axis of the kinematically aligned TKA (KAA) were templated on axial MRI images by two, independent observers. The relationships between the KAA, TEA, APA, and PCA were determined, with a negative value indicating relative internal rotation of the axis. Results On average, the KAA was 0.5° externally rotated relative to the PCA (minimum of −3.6°, maximum of 5.8°), −4.0° internally rotated relative to the TEA (minimum of −10.5°, maximum of 2.3°), and −96.4° internally rotated relative to the APA (minimum of −104.5°, maximum of −88.5°). Each of these relationships exhibited a wide range of potential values. Conclusions Using a kinematically aligned surgical technique internally rotates the posterior femoral axis relative to the transepicondylar axis, which significantly differs from current alignment instrument targets.


      PubDate: 2014-07-27T22:28:39Z
       
  • Design Changes Improve Contact Patterns and Articular Surface Damage in
           Total Knee Arthroplasty
    • Abstract: Publication date: Available online 25 July 2014
      Source:The Knee
      Author(s): Susannah L. Gilbert , Adam J. Rana , Joseph D. Lipman , Timothy M. Wright , Geoffrey H. Westrich
      Background The Optetrak® PS (Exactech, Inc., Gainesville, FL) has been a well-functioning posterior stabilized knee replacement since its introduction in 1995. In 2009, the Optetrak Logic® incorporated modifications to the anterior face of the tibial post and the corresponding anterior articulating surface of the femoral component to reduce edge loading on the polyethylene post. In this study, we provide the rationale for the design change and compare the damage on retrieved tibial components of both designs to demonstrate the effectiveness of the design modifications in decreasing post damage. Methods We integrated retrieval findings of tibial post damage with finite element analysis to redesign the anterior tibial post-femoral box articulation. We then used subsequent retrieval analysis on a 3:1 matched sample of 60 PS and 20 Logic® inserts to examine the impact of the design change on polyethylene damage. Results Polyethylene stresses were markedly reduced when rounded contact geometries were incorporated. The comparison of the new and old design using retrieval analysis demonstrated that the redesign led to reduction in surface damage and deformation on the tibial post. Conclusions This study shows the use of a design cycle by which a problem is identified through retrieval analysis, analytical tools are used to suggest design solutions, and then retrieval analysis is applied again on the new design to confirm improved performance. Clinical Relevance Anterior post damage has been markedly reduced through the introduction of design changes to the post-box geometry.


      PubDate: 2014-07-27T22:28:39Z
       
  • Case report: Total knee arthroplasty polyethylene liner disengagement
           identified by arthrography
    • Abstract: Publication date: Available online 26 July 2014
      Source:The Knee
      Author(s): David A. Bradshaw , Brian Lam , Rebekah Hoffman , Bernard Zicat
      We report a case of total knee arthroplasty polyethylene liner disengagement identified by plain film arthrography and CT arthrography.


      PubDate: 2014-07-27T22:28:39Z
       
  • Comparison of three knee braces in the treatment of medial knee
           osteoarthritis
    • Abstract: Publication date: Available online 27 July 2014
      Source:The Knee
      Author(s): Yoann Dessery , Étienne L. Belzile , Sylvie Turmel , Philippe Corbeil
      Background Conservative orthotic treatments rely on different mechanisms, such as three-point bending systems or hinges forcing external rotation of the leg and knee stabilization, to alter the biomechanics of the lower limbs and thus reduce knee loading on the affected compartment in patients with knee osteoarthritis (KOA). No previous study had compared the effects of these mechanisms on external loading and leg kinematics in patients with KOA. Methods Twenty-four patients with medial KOA (Kellgren-Lawrence grade II or III) wore three custom knee braces: a valgus brace with a three-point bending system (V3P-brace), an unloader brace with valgus and external rotation functions (VER-brace) and a functional knee brace used in ligament injuries (ACL-brace). Pain relief, comfort, kinematics and kinetics of the lower limbs during walking were compared with and without each knee brace. Results Knee pain was alleviated with all three braces (p<.01; ES=.17–.54). The VER- and ACL-braces allowed a significant reduction in peak knee adduction moment (KAM) during terminal stance from 0.313 to 0.280Nm/Bw*Ht (p<.001; ES=.28) and 0.293 to 0.268 (p<.05; ES=.22), respectively, while no significant reduction was observed with the V3P-brace (p=.52; ES=.04). Reduced knee adduction and lower ankle and knee external rotation were observed with the V3P-brace but not with the VER-brace. The ACL-brace did not modify lower limb kinematics. Conclusions No difference between the knee braces was found for pain reduction, discomfort or KAM. The VER-brace was slightly more comfortable, mainly because of its smaller size, which could ensure better compliance with treatment over the long term.


      PubDate: 2014-07-27T22:28:39Z
       
  • Asymmetries in explosive strength following anterior cruciate ligament
           reconstruction
    • Abstract: Publication date: Available online 27 July 2014
      Source:The Knee
      Author(s): Olivera M. Knezevic , Dragan M. Mirkov , Marko Kadija , Aleksandar Nedeljkovic , Slobodan Jaric
      Background Despite its apparent functional importance, there is a general lack of data regarding the time-related changes in explosive strength and the corresponding side-to-side asymmetries in individuals recovering from an ACL reconstruction (ACLR). The present study was designed to assess changes in the maximum and explosive strength of the quadriceps and hamstrings muscle in athletes recovering from an ACLR. Methods Twenty male athletes with an ACL injury completed a standard isometric testing protocol pre-ACLR, 4 and 6 months post-ACLR. In addition to the maximum strength (Fmax), the explosive strength of quadriceps and hamstrings was assessed through 4 variables derived from the slope of the force-time curves over various time intervals (RFDmax, RFD50, RFD150 and RFD250). Side-to-side asymmetries were calculated relative to post-ACLR measures of the uninvolved leg (“standard” asymmetries), and relative to pre-ACLR value of the uninvolved leg (“real” asymmetries). Results Pre-ACLR asymmetries in quadriceps RFD (average 26%) were already larger than in Fmax (14%) (p<0.05). Six months post-ACLR real asymmetries in RFD variables (33-39%) were larger than the corresponding standard asymmetries (26-28%; p<0.01). Average asymmetries in hamstrings RFD and Fmax were 10%, 25% and 15% for pre-ACLR and two post-ACLR sessions, respectively (all p>0.05). Conclusions In addition to the maximum strength, the indices of explosive strength should also be included in monitoring recovery of muscle function following an ACLR. Furthermore, pre-injury/reconstruction values should be used for the post-ACLR side-to-side comparisons, providing a more valid criterion regarding the muscle recovery and readiness for a return to sports.


      PubDate: 2014-07-27T22:28:39Z
       
  • Fixed bearing lateral unicompartmental knee arthroplasty—Short to
           midterm survivorship and knee scores for 101 prostheses
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): James R.A. Smith , James R. Robinson , Andrew J. Porteous , James R.D. Murray , Mohammad A. Hassaballa , Neil Artz , John H. Newman
      Background Isolated unicompartmental knee arthritis is less common laterally than medially. Lateral unicompartmental knee arthroplasty (UKA) constitutes only 1% of all knee arthroplasty performed. Use of medial UKA is supported by several published series showing good long-term survivorship and patient satisfaction, in large patient cohorts. Results of lateral UKA however have been mixed. We present the short and mid-term survivorship and 5-year clinical outcome of 101 lateral UKAs using a single prosthesis. Methods Over a 9year period, 100 patients who satisfied inclusion criteria underwent a lateral fixed-bearing unicompartmental arthroplasty. American Knee Society (AKSS), Oxford Knee (OKS) and modified Western Ontario McMaster Universities Arthritis Index (WOMAC) scores were completed preoperatively and at 1, 2 and 5years postoperatively. Kaplan–Meier survival analysis was used to determine the 2-year and 5-year survivorship, using revision for any cause as end point. Results Survivorship was 98.7% and 95.5% at 2 and 5years respectively. 1 knee was revised for subsidence of the tibial component and 1 knee for progression of medial compartment osteoarthritis. Of a possible 35 knees in situ at 5year follow-up, 33 knees were fully scored. Median AKSS, OKS and modified WOMAC scores were 182, 41, and 16 respectively. Conclusions The mid-term survivorship and outcome scores at 5-years suggest that lateral unicompartmental knee arthroplasty provides a valuable alternative to total joint replacement in selected patients with isolated lateral tibio-femoral arthritis at mid-term follow-up. Level II evidence.


      PubDate: 2014-06-10T16:13:21Z
       
  • Letter regarding “Does cruciate-retaining total knee arthroplasty
           enhance knee flexion in Western and East Asian patient populations' A
           meta-analysis”
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Xiaobo Xie , Lijun Lin , Qi Li



      PubDate: 2014-06-10T16:13:21Z
       
  • British Association for Surgery of the Knee
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4




      PubDate: 2014-06-10T16:13:21Z
       
  • Instructions for Authors
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4




      PubDate: 2014-06-10T16:13:21Z
       
  • Tricompartmental resurfacing arthroplasty with a follow-up of more than
           30years
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Emmanuel Thienpont , Philippe Cartier
      Background Unicompartmental and patellofemoral joint replacements are proven solutions for arthritis limited to one compartment of the knee. Bicompartmental replacement has been considered lately as an alternative for combined medial and patellofemoral arthritis. The main idea behind these resurfacing solutions is tissue preservation with conservation of bone stock and both cruciate ligaments. Tricompartmental replacement with selective resurfacing of all three compartments with different modular implants is exceptional. Methods The authors present a case with more than thirty year follow-up both clinically and radiographically. Results Excellent function and patient satisfaction are observed at 30year follow-up. Radiographs show no osteolysis or loosening of components. Conclusions Conservation of both anterior and posterior cruciate ligaments seems to protect against polyethylene wear at long-term follow-up. Level of evidence IV.


      PubDate: 2014-06-10T16:13:21Z
       
  • An original arthroscopic fixation of adult's tibial eminence fractures
           using the Tightrope® devi A report of 8 cases and review of
           literature
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Bruno Faivre , Horea Benea , Shahnaz Klouche , Florent Lespagnol , Thomas Bauer , Philippe Hardy
      Purpose The objective of this study is to asset the efficiency of the use of the Tightrope® device to treat isolated tibial spine fractures in adults. Methods All patients treated for isolated tibial spine fracture between November 2007 and February 2011 have been retrospectively included. The main judgment criteria was the post-operative knee laxity measured by Rolimeter® (Aircast) and the secondary criteria were the IKDC scores, the knee mobility, the Lachman test and the bone union. 8 patients have been included. The mean age was 34.2years (±12.5). The classification of Meyers and McKeever identified 5 types II, 2 types IIIa and 1 type IIIb. The mean follow-up period was 10months. Results The mean post-operative anterior knee laxity was 6±2.14mm for the operated side and 5.6±1.85mm for the opposite side. No significant difference was found (P =0.73). According to the IKDC classification 3 patients were normal (A), 2 were nearly normal (B), 1 was abnormal (C) and 1 was very abnormal (D). The mean IKDC subjective score was 70.71±17.56. All 8 fractures achieved union without elevation. 3 patients developed motion complications and 2 required an arthroscopic arthrolysis. No other significant complication was noted. The outcome was compared to the different series published during the last 10years. Conclusion The use of the Tightrope® device is a simple technique occurring a rigid fixation, allowing early rehabilitation with a high rate of arthrofibrosis. Level of evidence Level IV, case series.


      PubDate: 2014-06-10T16:13:21Z
       
  • Fracture of titanium nitride-coated femoral component after total knee
           arthroplasty
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Se-Wook Park , Hyungsuk Kim , Yong In
      We report a case of fracture of a titanium nitride-coated femoral component 3years after primary total knee arthroplasty (TKA). The fracture was at the medial condylar area just posterior to the medial peg of the femoral component. The backside of the broken medial condylar portion of the femoral component was devoid of cement. Debonding of the component is a possible cause of the stress fracture. To our knowledge, this is the first case report of the fracture of the femoral component manufactured from titanium alloy. Level of evidence IV


      PubDate: 2014-06-10T16:13:21Z
       
  • Patient satisfaction after posterior-stabilized total knee arthroplasty: A
           functional specific analysis
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Hui Du , Hao Tang , Jian-Ming Gu , Yi-Xin Zhou
      Background Despite the success of total knee arthroplasty (TKA) in treating end-stage knee arthritis, 11% to 19% of patients are dissatisfied with the outcome of their surgery. In this study we investigated how satisfied overall patients are with the outcome of posterior stabilized TKA and what particular functional deficits or residual symptoms cause the most dissatisfaction for patients after surgery. Methods Using patient-completed validated questionnaires, we retrospectively analyzed data for 1013 posterior-stabilized TKAs performed in 748 Chinese patients regarding the overall satisfaction with surgery and the importance ranking of each of 15 specific functions and residual symptoms. Results Our data demonstrate an overall satisfaction rate of 87.4%. Satisfaction percentages ranged from 45.0% to 89.0%. The top 6 dissatisfactory items were sitting with legs crossed (dissatisfaction rate of 55.0%), squatting (51.7%), walking fast or jogging (45.4%), knee clunking (34.5%), abnormal feeling in knee (31.2%), and climbing stairs (28.2%). The top 6 important functions or issues were pain relief, walking on flat ground, climbing stairs, ability to return to household work, decreased limping, and squatting. Conclusions Approximately 1 in 8 patients was dissatisfied with overall outcome. Patients were most dissatisfied with climbing stairs and squatting, functions that they considered most important.


      PubDate: 2014-06-10T16:13:21Z
       
  • No effect of obesity on limb and component alignment after
           computer-assisted total knee arthroplasty
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Gautam M. Shetty , Arun B. Mullaji , Sagar Bhayde , A.P. Lingaraju
      Purpose This retrospective study aimed to determine if computer navigation provides consistent accuracy for limb and component alignment during TKA irrespective of body mass index (BMI) by comparing limb and component alignment and the outlier rates in obese versus non-obese individuals undergoing computer-assisted TKA. Methods Six hundred and thirty-five computer assisted total knee arthroplasties (TKAs) performed in non-obese individuals (BMI<30kg/m2) were compared with 520 computer-assisted TKAs in obese individuals (BMI≥30kg/m2) for postoperative limb and component alignment using full length standing hip-to-ankle radiographs. Results No significant difference in postoperative limb alignment (179.7°±1.7° vs 179.6°±1.8°), coronal femoral (90.2°±1.6° vs 89.8°±1.9°) and tibial component (90.2°±1.6° vs 90.3°±1.7°) alignment and outlier rates (6.2% vs 7.5%) was found between non-obese and obese individuals. Similarly, alignment and the outlier rates were similar when non-obese individuals and a subgroup of morbidly obese individuals (BMI >40kg/m2) were compared. Conclusions Computer navigation can achieve excellent limb and component alignment irrespective of a patient's BMI. Although obesity may not be an indication per se for using computer navigation during TKA, it will help achieve consistently accurate limb and component alignment in obese patients. Level of Evidence Level II


      PubDate: 2014-06-10T16:13:21Z
       
  • Effects of increased step width on frontal plane knee biomechanics in
           healthy older adults during stair descent
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Max R. Paquette , Songning Zhang , Clare E. Milner , Jeffrey T. Fairbrother , Jeffrey A. Reinbolt
      Background Peak internal knee abduction moment is a common surrogate variable associated with medial compartment knee loading. Stair descent has been shown to yield a greater peak knee abduction moment compared to level-walking. Changes in step width (SW) may lead to changes in frontal plane lower extremity limb alignment in the frontal plane and alter peak knee abduction moment. The purpose of this study was to investigate the effects of increased SW on frontal plane knee biomechanics during stair descent in healthy older adults. Methods Twenty healthy adults were recruited for the study. A motion analysis system was used to obtain three-dimensional lower limb kinematics during testing. An instrumented 3-step staircase with two additional customized wooden steps was used to collect ground reaction forces (GRF) data during stair descent trials. Participants performed five stair descent trials at their self-selected speed using preferred, wide (26% leg length), and wider (39% leg length) SW. Results The preferred normalized SW in older adults during stair descent was 20% of leg length. Wide and wider SW during stair descent reduced both first and second peak knee adduction angles and abduction moments compared to preferred SW in healthy adults. Conclusions Increased SW reduced peak knee adduction angles and abduction moments. The reductions in knee abduction moments may have implications in reducing medial compartment knee loads during stair descent.


      PubDate: 2014-06-10T16:13:21Z
       
  • Development and validation of formulae to predict leg length following
           medial opening-wedge osteotomy of the proximal tibia with hemicallotasis
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Eiichi Nakamura , Nobukazu Okamoto , Hiroaki Nishioka , Hiroki Irie , Hiroshi Mizuta
      Background A medial open-wedge osteotomy of the proximal tibia with hemicallotasis (HCO) affects the relative coronal alignment of the femur and tibia with respect to the floor; this also potentially reflects a change in leg length. Purpose The aims of this study are to develop and verify formulae for predicting the postoperative whole leg length (WLL) in HCO. Methods We analyzed a training set of 25 HCOs in 25 patients. Formulae for predicting the postoperative leg length were developed using various factors including the length and coronal alignment of the femur and tibia, the length of the proximal or distal fragment from the tibial osteotomy site, the femoro–tibial angle, and the correction angle. The formulae were then verified using the interclass correlation coefficient in an independent consecutive set of 25 HCOs. Results Significant postoperative increases in tibial bone length and WLL were noted with no postoperative change in femoral bone length. Furthermore, the coronal alignments of femoral and tibial bone axes were significantly abducted. For the formulae for predicting postoperative WLL developed in the training set, the interclass correlation coefficients between the predicted values and the real radiographic measurements in the validation set were more than 0.90, showing great consistency. Conclusion The mathematical models established in this study seemed to predict almost completely the change in leg length after HCO. Our results suggest that these formulae may offer accurate, extremely useful information about the postoperative possibility of leg lengthening for patients planning an HCO. Level of evidence Therapeutic case series; level 4.


      PubDate: 2014-06-10T16:13:21Z
       
  • Oxidized zirconium femoral component for TKA: A follow-up note of a
           previous report at a minimum of 10years
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Massimo Innocenti , Fabrizio Matassi , Christian Carulli , Lorenzo Nistri , Roberto Civinini
      Background New bearing surfaces for total knee replacement have been described in an attempt to reduce polyethylene wear and secondary osteolysis and improve longevity of implants. Oxidized zirconium is a new material that combines the strength of a metal with the wear properties of a ceramic. However, there are no reports as to who documents the long term results. We report a 10year follow-up note of a selected series of TKAs with an oxidized zirconium femoral component. Methods We prospectively follow 98 TKAs performed in 94 patients with an oxidized zirconium femoral component. Five patients (5 knees) had died and 6 (6 knees) were lost to follow-up at a minimum of 2years (mean, 6.3years; range, 2–9years) after the operation. For the remaining 83 patients (87 knees), the minimum follow-up was 10years (mean, 11.3years; range, 10.0–12.6years). In 51 cases (58.6%), a cruciate-retaining implant with a deep-dished, more conforming PE was used, and in 36 cases (41.4%), a posterior-stabilized design was used. The patellae were resurfaced in 32 cases (36.7%) and in 55 cases (63.3%) were left unresurfaced. Results Survivorship was 97.8% at 10years postoperatively. Two knees were revised for aseptic loosening of the femoral component. No major complication was observed clinically or radiologically. Mean Knee Society score improved from 36 to 84 and functional score from 37 to 83. Conclusions Oxidized zirconium femoral component in TKA performs well over the first 10years following implantation, with excellent survival rates and good clinical and radiological outcomes. Level of evidence Level IV, therapeutic study.


      PubDate: 2014-06-10T16:13:21Z
       
  • Sealing of the intramedullar femoral canal in a TKA does not reduce
           postoperative blood loss: A randomized prospective study
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Raúl Torres-Claramunt , Pedro Hinarejos , Daniel Pérez-Prieto , Sergi Gil-González , Xavier Pelfort , Joan Leal , Lluís Puig
      Background Sealing of the femoral canal, usually with autologous bone, is a surgical procedure that is often performed during TKA surgery to decrease blood loss in the postoperative period. However, evidence as to the effectiveness of this surgical procedure is not conclusive. The objective of this study was to assess the effectiveness of this surgical action in reducing postoperative blood loss and the blood transfusion rate. Methods A randomized prospective study that included 201 TKAs divided into three groups (67 in each one) was carried out. The three groups were; A) bone graft sealing, B) cement sealing and C) unsealed canal. All groups were comparable with regard to pre and intra-operative data. The haemoglobin decrease at 2, 24 and 72h was compared to the preoperative haemoglobin value. Subsequently, blood drainage at 12 and 24h and the rate of blood transfusion were also assessed. The different complications that arose were reported. Results No statistical differences were obtained with regard to blood drainage at 12h (p=0.102) and 24h (p=0.542), the haemoglobin value decrease at 72h (p=0.95) and the number of blood transfusions (p=0.597) in the three groups studied. Conclusion There was no significant difference, whether sealing the femoral canal with a bone graft, cement or when it was left unsealed, in decreasing blood loss or blood transfusion requirements in the postoperative period. Level of evidence Therapeutic type I.


      PubDate: 2014-06-10T16:13:21Z
       
  • Comparison of peripheral nerve block with periarticular injection
           analgesia after total knee arthroplasty: A randomized, controlled study
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Kazuhide Uesugi , Naoko Kitano , Tadashi Kikuchi , Miho Sekiguchi , Shin-ichi Konno
      Background Pain after total knee arthroplasty (TKA) is usually severe. Recently, the usefulness of local periarticular injection analgesia (PAI) and peripheral nerve block (PNB) has been reported. We report a prospective blinded randomized trial of PAI versus PNB in patients undergoing primary TKA, in accordance with the CONSORT statement 2010. Methods A total of 210 patients undergoing TKA under spinal anesthesia were randomized to receive PNB group or PAI group. In the PNB group, femoral nerve block and sciatic nerve block were performed. In the PAI group, a special mixture containing ropivacaine, saline, epinephrine, morphine hydrochloride, and dexamethasone was injected into the periarticular soft tissue. Pain intensity at rest was assessed using a numerical rating scale (NRS: 0–10) after surgery. Use of a diclofenac sodium suppository (25mg) was allowed for all patients at any time after surgery, and the diclofenac sodium suppository usage was assessed. The NRS for patient satisfaction at 48hours after surgery was examined. Results The average NRS for pain at rest up to 48hours after surgery was low in both groups. Within 48hours after surgery, the diclofenac sodium suppository usage was similar in both groups. There were no significant differences in the NRS for patient satisfaction in both groups. Conclusions The analgesic effects of PAI and PNB are similar. PAI may be considered superior to PNB because it is easier to perform. Level of Evidence Therapeutic Level 1.


      PubDate: 2014-06-10T16:13:21Z
       
  • Contents List
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4




      PubDate: 2014-06-10T16:13:21Z
       
  • Editorial Board
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4




      PubDate: 2014-06-10T16:13:21Z
       
  • The management of early osteoarthritis
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Roland Jakob



      PubDate: 2014-06-10T16:13:21Z
       
  • Influence of the posterior tibial slope on the flexion gap in total knee
           arthroplasty
    • Abstract: Publication date: August 2014
      Source:The Knee, Volume 21, Issue 4
      Author(s): Ken Okazaki , Yasutaka Tashiro , Hideki Mizu-uchi , Satoshi Hamai , Toshio Doi , Yukihide Iwamoto
      Background Adjusting the joint gap length to be equal in both extension and flexion is an important issue in total knee arthroplasty (TKA). It is generally acknowledged that posterior tibial slope affects the flexion gap; however, the extent to which changes in the tibial slope angle directly affect the flexion gap remains unclear. This study aimed to clarify the influence of tibial slope changes on the flexion gap in cruciate-retaining (CR) or posterior-stabilizing (PS) TKA. Methods The flexion gap was measured using a tensor device with the femoral trial component in 20 cases each of CR- and PS-TKA. A wedge plate with a 5° inclination was placed on the tibial cut surface by switching its front–back direction to increase or decrease the tibial slope by 5°. The flexion gap after changing the tibial slope was compared to that of the neutral slope measured with a flat plate that had the same thickness as that of the wedge plate center. Results When the tibial slope decreased or increased by 5°, the flexion gap decreased or increased by 1.9±0.6mm or 1.8±0.4mm, respectively, with CR-TKA and 1.2±0.4mm or 1.1±0.3mm, respectively, with PS-TKA. Conclusions The influence of changing the tibial slope by 5° on the flexion gap was approximately 2mm with CR-TKA and 1mm with PS-TKA. Clinical relevance This information is useful when considering the effect of manipulating the tibial slope on the flexion gap when performing CR- or PS-TKA.


      PubDate: 2014-06-10T16:13:21Z
       
  • Magnetic resonance evaluation of Trufit® plugs for the treatment of
           osteochondral lesions of the knee shows the poor characteristics of the
           repair tissue
    • Abstract: Publication date: Available online 9 May 2014
      Source:The Knee
      Author(s): Pablo Eduardo Gelber , Jorge Batista , Angélica Millan-Billi , Luciano Patthauer , Silvia Vera , Mireia Gomez-Masdeu , Juan Carlos Monllau
      Background Treatment of osteochondral lesions of the knee with synthetic scaffolds seems to offer a good surgical option preventing donor site morbidity. The Trufit® plug has shown that frequently is not properly incorporated. Objective To evaluate the relationship between the MRI findings and the functional scores of patients with osteochondral lesions of the knee treated with Trufit®. Methods Patients were evaluated with the MOCART score for MRI’s assessment of the repair tissue. KOOS, SF-36 and VAS were used for clinical evaluation. Correlation between the size of the treated chondral defect and functional scores were were also analyzed. Results Fifty-seven patients with a median follow-up of 44.8months (range 24–73) were included. KOOS, SF-36 and VAS improved from a mean 58.5, 53.9 and 8.5 points to a mean 87.4, 86.6 and 1.2 at last follow-up (p<0.001). Larger lesions showed less improvement in KOOS (p=0.04) and SF-36 (p=0.029). Median Tegner’s values were restored to the preinjury situation (5, range 2–10). Mean MOCART score was 43.2±16.1. Although the cartilage layer had good integration, it showed high heterogeneity and no filling of the subchondral bone layer. Conclusions Trufit® failed to restore the normal MRI aspect of the subchondral bone and lamina in most cases. The aspect of the chondral layer in MRI was partially re-established. This unfavorable MRI aspect did not adversely influence the patient’s outcome in the short time and they restored their previous level of activity. There was an inverse linear relationship between the size of the lesion and the functional scores. Level of Evidence Therapeutic case series; level 4.


      PubDate: 2014-05-12T06:37:47Z
       
  • 5-year cost/benefit analysis of revision of failed uni-compartmental Knee
           (UKR) replacements; not “just” a primary total knee
           replacement (TKR)
    • Abstract: Publication date: Available online 6 May 2014
      Source:The Knee
      Author(s): Sam C. Jonas , Rushabh Shah , Aveek Mitra , Sunny D. Deo
      Background A number of studies suggest that one advantage of a Unicompartmental knee replacement (UKR) is ease of revision to a total (TKR). We aimed to perform a cost/benefit analysis of patients undergoing this procedure at our centre to evaluate its economic viability. Patients and Methods From our own prospective joint replacement database we identified 812 consecutive tibio-femoral UKRs performed (1994–2007) of which 23 were revised to TKR (2005–2008). These were then matched to a cohort of primary TKRs (42 patients). Data were collected regarding patient demographics, cost of surgery, clinical outcome (OKS) and follow up costs at five years. Results There was no significant difference in implant costs or in length of stay, however tourniquet time was significantly higher in the revision group (Average 93minutes (UKR) vs 75minutes (TKR) p<0.0001). At five years there was no significant difference in clinical outcome between the revision UKR and primary TKR group, mean OKS 27 and 32 respectively (p=0.20). The revision group had a greater complication and revision rate, attending significantly more follow-up appointments (Average 6 (UKR) vs 2 (TKR) p<0.0001) and consultant appointments (Average 4 (UKR) vs 0.4 (TKR) p<0.0001). This was translated to significantly higher follow up costs. Conclusion Revision of UKR to TKR is not universally a straightforward procedure comparable to a standard primary replacement. Despite cost of components not being significantly higher than primary TKR there are multiple hidden follow up costs. The clinical outcomes are however similar at 5years, indicating a favourable cost benefit.


      PubDate: 2014-05-07T06:48:24Z
       
  • Intraoperative assessment of midflexion laxity in total knee prosthesis
    • Abstract: Publication date: Available online 26 April 2014
      Source:The Knee
      Author(s): Yukihide Minoda , Shigeru Nakagawa , Ryo Sugama , Tessyu Ikawa , Takahiro Noguchi , Masashi Hirakawa , Hiroaki Nakamura
      Purpose Soft-tissue balancing of the knee is fundamental to the success of a total knee arthroplasty (TKA). In posterior-stabilized TKA, there is no stabilizer of the anterior-posterior translation in the midflexion range in which the cam-post mechanism does not engage yet. Therefore, instability in the midflexion range is suspected to occur in posterior-stabilized TKA. The purpose of this study was to measure the joint gap throughout full range of motion and to analyze the joint gap laxity in midflexion range after implantation of a mobile-bearing posterior-stabilized total knee prosthesis. Methods Joint gap kinematics in 259 knees with varus osteoarthritis were measured during TKAs using a tensor device with the same shape of a total knee prosthesis of the same design was used. After the implantation of a mobile-bearing posterior-stabilized prosthesis and the reduction of the patellofemoral joint, the joint gap was measured at 0°, 30°, 60°, 90°, 120°, and 145° of flexion. Results The center size of the joint gap was tight in extension and deep flexion and loose at midflexion ranges, especially at 30° of flexion (p<0.001). The symmetry of the joint gap was varus at 0° and 145°of flexion (p<0.001). Conclusions Our results showed the joint gap laxity in midflexion range after the implantation of a mobile-bearing posterior-stabilized prosthesis. Our new tensor device, which can attach the polyethylene insert trial, will provide the important information about the joint gap kinematics after implantation of total knee prostheses.


      PubDate: 2014-04-27T11:15:35Z
       
  • Surface extraction can provide a reference for micro-CT analysis of
           retrieved total knee implants
    • Abstract: Publication date: Available online 26 April 2014
      Source:The Knee
      Author(s): Matthew G. Teeter , Jaques S. Milner , Douglas D.R. Naudie , Steven J. MacDonald
      Background Quantitative measurements of damage and wear in orthopaedic components retrieved from patients during revision surgery can provide valuable information. However, to perform these measurements there needs to be an estimate of the original, unworn geometry of the component, often requiring multiple scans of the various sizes of components that have been retrieved. The objective of this study was to determine whether the articular and backside surfaces could be independently segmented from a micro-CT reconstruction of a tibial insert, such that a tibial insert of one thickness could be used as a reference for a tibial insert of a different thickness. Methods New tibial inserts of a single width but six different thicknesses were obtained and scanned with micro-CT. An automated method was developed to computationally segment the articular and backside surfaces of the components. Variability between intact and extracted components was determined. Results The deviations between the comparisons of the extracted surfaces (range, 0.0004 to 0.010mm) were less (p<0.001) than the baseline deviation between the intact surfaces (range, 0.0002 to 0.053mm). Conclusions An extracted surface from one insert thickness could be used to accurately represent the surface of an insert of a different thickness. This greatly enhances the feasibility of performing retrieval studies using micro-CT as a quantitative tool, by reducing the costs and time associated with acquiring, scanning, and reconstructing multiple reference tibial insert geometries. This will add greater detail to studies of retrieved implants, to better establish how implants are functioning in vivo.


      PubDate: 2014-04-27T11:15:35Z
       
 
 
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