The Knee

Contents List

2012-06-01

Editorial Board

2012-06-01

Editorial: Keywords

Simon Donell, Michael Ries — 2012-06-01

Authors need to be aware of the importance of the Key Words that they use to describe their submissions. A recent paper in The Knee failed to cite a paper in another journal, Arthroscopy which described the same technical tip for wire passage in PCL reconstruction. Neither the authors nor the reviewers picked up the earlier paper. Simple searches using the Medline and Scopus search engines also failed to pick up the earlier publication. The problem was the “Key Words” used to describe it “Posterior cruciate ligament, reconstruction, graft passage”. Missing was “Novel, technique”.

Periprosthetic fractures in the distal femur following total knee replacement: A review and guide to management

Andrew T. Johnston, Elefterios Tsiridis, Keith S. Eyres, Andrew D. Toms — 2011-07-11

Abstract: The management of distal femoral fractures following a total knee replacement can be complex and requires the equipment, perioperative support and surgical skills of both trauma and revision arthroplasty services. Recent advances in implant technology have changed the management options of these difficult fractures. This article describes the options available and discusses the latest evidence.

Effect of footwear on the external knee adduction moment — A systematic review

Andy Oliver Radzimski, Annegret Mündermann, Gisela Sole — 2011-07-06

Abstract: Context: Footwear modifications have been investigated as conservative interventions to decrease peak external knee adduction moment (EKAM) and pain associated with knee osteoarthritis (OA).Objective: To evaluate the literature on the effect of different footwear and orthotics on the peak EKAM during walking and/or running.Methods: A systematic search of databases resulted in 348 articles of which 33 studies were included.Results: Seventeen studies included healthy individuals and 19 studies included subjects with medial knee OA. Quality assessment (modified Downs and Black quality index) showed an (average±SD) of 73.1±10.1%. The most commonly used orthotic was the lateral wedge, with three studies on the medial wedge. Lateral wedging was associated with decreased peak EKAM in healthy participants and participants with medial knee OA while there is evidence for increased peak EKAM with the use of medial wedges. Modern footwear (subjects' own shoe, “stability” and “mobility” shoes, clogs) were likely to increase the EKAM compared to barefoot walking in individuals with medial knee OA. Walking in innovative shoes (“variable stiffness”) decreased the EKAM compared to control shoes. Similarly, shoes with higher heels, sneakers and dress shoes increased EKAM in healthy individuals compared to barefoot walking.Conclusions: Further development may be needed toward optimal footwear for patients with medial knee OA with the aim of obtaining similar knee moments to barefoot walking.

The effect of gender on outcome of unicompartmental knee arthroplasty

S. Lustig, N. Barba, R.A. Magnussen, E. Servien, G. Demey, P. Neyret — 2011-03-28

Abstract: No report has specifically addressed the question of the influence of gender on outcome following unicompartmental knee arthroplasty (UKA). To clarify this issue, we studied two groups of 40 patients of each gender, matched by pre-operative clinical and radiological presentation, and with post-operative follow up of at least 2years. The mean age at operation was 71years and the mean follow-up was 5.9years. In both groups, IKS score improved significantly, but without difference based on gender. No difference was found between groups in terms of range of motion, alignment, or radiologic progression of arthritis. These results suggest that when utilizing specific patient selection criteria, gender does not influence outcome following UKA.

Functional relevance of patellofemoral thickness before and after unicompartmental patellofemoral replacement

A. Mofidi, S. Bajada, M.D. Holt, A.P. Davies — 2011-04-14

Abstract: The aim of this study was to assess the increase in the anterior height of the knee after unicompartmental patellofemoral replacement and the impact of this increase on the range of motion and function of the knee.Twenty-eight patients (34 knees) who underwent patellofemoral replacement with FPVTM prosthesis between 2005 and 2009 were identified and retrospectively analyzed using chart and radiological review.Trochlear height and patellar thickness were measured combined and compared pre and postoperatively. The range of movement and functional outcome scores after 6–12months follow-up were noted. The effect of increased postoperative anterior–posterior height of the knee on the range of motion was studied.Postoperative mean range of flexion of the knee joint was 116°. The mean Oxford knee score was 21 points. The mean American Knee Society Knee Score was 80 points for pain and 61 points for function.The trochlear height and patellar thickness were increased by 3.5 and 2.5 mms respectively, resulting in average total increase of 6mm in the anterior–posterior height of the knee. We found no relationship between range of motion and function of the knee and the increase in the anterior–posterior height. We found a negative correlation between increase in the anterior–posterior height and preoperative anterior–posterior height.FPV patellofemoral replacement results in correct anatomical reconstruction of the trochlear height rather than ‘overstuffing’ of the patellofemoral joint. There is an increase in anterior–posterior height of the knee but this does not affect range of movement or clinical outcome.

Effects of cartilage remnants of the posterior femoral condyles on femoral component rotation in varus knee osteoarthritis

2011-03-14

Abstract: Preoperative planning of total knee arthroplasty (TKA) based on computerized tomography (CT) data can produce a femoral rotational error due to lack of information on the femoral cartilage thickness. The research question of this study is how much femoral rotational error is expected due to the cartilage remnants when using the posterior condylar angles (PCA, angle between the posterior condylar line and the surgical epicondylar axis (SEA)) on CT data. CT arthrography was performed for 35 consecutive varus osteoarthritic knees in 31 patients who underwent TKA, on which the cartilage thicknesses of the posterior femoral condyles were measured. The PCAs when including or excluding the cartilage remnants were also measured. The cartilage thicknesses of the medial and lateral posterior condyles averaged 0.39mm (SD=0.53) and 1.55mm (SD=0.26), respectively (p<0.0001). When the cartilage was included or excluded, the PCA averaged 2.2° (SD=1.5) and 3.3° (SD=1.5), respectively (p=0.002). The cartilage remnants in the posterior femoral condyles produced an average of 1.1° and a maximum of 2.1° of additional femoral external rotation when using CT data for the preoperative planning. CT scan measurements of femoral rotation are subject to error. Although this is said to be small and within the safety margin for setting the femoral component parallel to the trans-epicondylar axis, this difference should be considered by surgeons who use the posterior condylar axis, in order to avoid excessive external rotation of the femoral component.

The timing of tourniquet release and ‘retransfusion’ drains in total knee arthroplasty: A stratified randomised pilot investigation

T. Dutton, R. De-Souza, N. Parsons, M.L. Costa — 2011-03-28

Abstract: The timing of tourniquet release is a potential confounding factor in the use of retransfusion drains in total knee arthroplasty. A pilot randomised trial was performed using retransfusion drains to determine whether releasing the tourniquet after wound closure reduced the overall blood loss and allogenic transfusion rate. Forty eight patients undergoing total knee arthroplasty were randomly allocated to receive either a retransfusion drain or no drain. Within each group the tourniquet was released before or after wound closure at the discretion of the surgeon. The peri-operative fall in haemoglobin, allogenic blood transfusion rate and complication rate were measured. There was an overall transfusion rate of 16%. There was no difference in the peri-operative fall in haemoglobin or the allogenic transfusion rates between the No Drain and Retransfusion Drain groups for patients undergoing total knee arthroplasty. Furthermore, the timing of the tourniquet release did not alter these findings. The results of this study suggest that the timing of the tourniquet release does not impact upon the ability of retransfusion drains to reduce the peri-operative fall in haemoglobin or the requirement for allogenic blood transfusion in total knee arthroplasty.

Telethermographic findings after uncomplicated and septic total knee replacement

C.L. Romanò, N. Logoluso, F. Dell'Oro, A. Elia, L. Drago — 2011-03-28

Abstract: Thermal imaging with infrared thermography is a noninvasive approach to monitoring surgical site healing and detecting septic complications. The aim of this study was to set reference values for telethermographic patterns of wound healing after total knee replacement (TKR) not complicated by infection and to compare them against thermograms from patients with knee prosthesis infection.Forty consecutive patients operated for TKR underwent telethermography of the operated and the contralateral knee before and up to 12 months after uncomplicated surgery. The imaging data sets were then compared against those obtained starting 8months after TKR in 15 other patients with diagnosed periprosthetic infection.Presurgical assessment thermograms showed no difference between the affected and the healthy knees. At assessment 3days postoperative, the temperature of the operated knee had increased markedly, with a peak differential temperature (operated minus non-operated knee joint temperature) of 3.4±0.7°C; measurement at 90 days after surgery showed a return to baseline knee joint temperature in the patients with uncomplicated surgery. In the patients with septic complications, the mean differential temperature was 1.6±0.6°C (range, 1.1–2.5°C).Thermal imaging showed a measurable, reproducible telethermographic pattern of surgical site healing in patients with uncomplicated TKR and an elevated mean differential temperature >1.0°C in those with persistent prosthesis infection.

Patellar reshaping versus resurfacing in total knee arthroplasty — Results of a randomized prospective trial at a minimum of 7years' follow-up

Zhong-tang Liu, Pei-liang Fu, Hai-shan Wu, Yunli Zhu — 2011-04-25

Abstract: Objective: To compare the results of primary total knee arthroplasty with patellar reshaping or resurfacing.Methods: One hundred thirty-three patients were randomized into patellar reshaping group and patellar resurfacing group. Patellar reshaping includes resecting the partial lateral facet of the patella and the osteophytes surrounding the patella, trimming the patella to match the trochlea of the femoral component. The minimum follow-up time was 7years. The outcome was measured by anterior knee pain rate, Knee Society clinical score, and radiographs.Results: Eight patients in the reshaping group (12.5%) and 10 patients in the resurfacing group (14.7%) complained of anterior knee pain (P=0.712). Meanwhile, there were no significant differences between the two groups in terms of total Knee Society score, Knee Society pain score, Knee Society function score, as well as anterior knee pain rate.Conclusions: With the numbers available, there was no significant difference between the groups treated with patellar reshaping or patellar resurfacing with regard to the KSS, anterior knee pain rate and radiographs. We prefer reshaping the patella to resurfacing the patella because the former preserves sufficient patellar bone stock and can easily be converted to patellar replacement if patients complain of recurrent anterior knee pain.

Osteoporosis affects component positioning in computer navigation-assisted total knee arthroplasty

2011-04-29

Abstract: Although computer-assisted navigation in total knee arthroplasty (TKA) has many advantages, undetected tracker pin movement can result in poor lower limb alignment and component position. Osteoporosis may be an underlying cause of tracker pin movement. The present prospective case–control study compared 6-month radiographic outcomes in 44 osteoporotic and 56 non-osteoporotic knees undergoing navigation TKAs. Osteoporotic knees were defined as those having a T-score of −2.5 or less either in the femoral neck or lumbar spine or both. At postoperative 6months' follow-up, the average coronal tibial component position was greater valgus in osteoporotic group than in nonosteoporotic group (non-osteoporotic=varus 0.7°±1.8°; osteoporotic=valgus 1.2°±3.4°; p=0.041). Multiple linear regression analysis showed that being in the osteoporotic group was a predictor of tibial coronal component position (β=0.321, p=0.039). In addition, preoperative lumbar spine bone mineral density was found to be a predictor of coronal and sagittal alignments of the tibial component (β=0.406, p=0.015, β=−0.463, p=0.007). The present study found that osteoporosis affected tibial component position in computer-assisted navigation TKA. Clinicians should be particularly aware of the possibility of undetectable tracker pin movement during navigation TKA in osteoporotic knees.

Age-related changes in kinematics of the knee joint during deep squat

2011-04-21

Abstract: Researchers frequently use the deep knee squat as a motor task in order to evaluate the kinematic performance after total knee arthroplasty. Many authors reported about the kinematics of a normal squatting motion, however, little is known on what the influence of aging is. Twenty-two healthy volunteers in various age groups (range 21–75years) performed a deep knee squat activity while undergoing motion analysis using an optical tracking system. The influence of aging was evaluated with respect to kinematics of the trunk, hip, knee and ankle joints. Older subjects required significantly more time to perform a deep squat, especially during the descending phase. They also had more knee abduction and delayed peak knee flexion. Older subjects were slower in descend than ascend during the squat. Although older subjects had a trend towards less maximal flexion and less internal rotation of the knee compared to younger subjects, this difference was not significant. Older subjects also showed a trend towards more forward leaning of the trunk, resulting in increased hip flexion and anterior thoracic tilt.This study confirmed that some aspects of squat kinematics vary significantly with age, and that the basic methodology employed here can successfully detect these age-related trends. Older subjects had more abduction of the knee joint, and this may indicate the load distribution of the medial and lateral condyles could be different amongst ages. Age-matched control data are therefore required whenever the performance of an implant is evaluated during a deep knee squat.

The impact of exsanguination by Esmarch bandage on venous hemodynamic changes in total knee arthroplasty — A prospective randomized study of 38 knees

Fang-Yao Chiu, Shih-Hsin Hung, Tien-Yow Chuang, Shu-Chiung Chiang — 2011-04-08

Abstract: Elastic (Esmarch) bandage exsanguination is widely used in lower limb surgery to provide a bloodless operating field. Nevertheless, it is still not known exactly how exsanguination through Esmarch bandage usage contributes to venous pressure physiology following TKA. We wished to determine whether exsanguination with Esmarch bandage affects the venous hemodynamics of the lower limb in the first few weeks following TKA, so a prospectively randomized study was set.We prospectively collected consecutive 38 male patients with unilateral advanced osteoarthritis of the knee. All of the subjects were randomly assigned to one of two TKA procedures: TKA with (Group A) or without (Group B) Esmarch bandage exsanguination. No pharmacologic thromboembolic prophylaxis was used in this study. The venous hemodynamics of each operated leg was assessed by strain-gage plethysmography, firstly before the operation, then postoperatively on days 2, 6, 14 and 28. The postoperative results revealed significant falls in venous outflow 2, 6 and 14days following TKA in Group A; and 2 and 6days following TKA in Group B. Twenty-eight days after TKA, venous outflow in both groups had returned to baseline level. Over the 28days following the operation, Group A venous outflow tended to fall more significantly than in Group B. As with venous outflow, venous capacitance in both groups showed significant falls 2 and 6days following TKA, with recovery to baseline levels 28days postoperation. More significant falls in arterial filling index were recorded in Group A 6days following TKA, returning to their baseline level 14days postoperation. It appears that better leg venous hemodynamic changes are attained during the first month after TKA in Group B. We therefore question the need for exsanguination with Esmarch bandage before knee arthroplasty.

Correction of knee deformity in patients with Ellis–van Creveld syndrome: A case report and review of the literature

Jens Arne Jöckel, Heiko Reichel, Manfred Nelitz — 2011-04-07

Abstract: Ellis–van Creveld Syndrome (EVC) is a rare autosomal recessive disorder. In 1940 Richard W. Ellis and Simon van Creveld first reported on a rare skeletal dysplasia, which to emphasize the main clinical characteristics, was termed “chondro-ectodermal dysplasia”. The ectodermal involvement includes the skin, hair and nails while the chondrodysplastic characteristics involve the cartilage and bones, primarily in the forearms and lower legs. For the orthopaedic surgeon progressive valgus knee deformity accompanied by patella dislocation is the main problem in EVC. This study reports a ten year follow-up after a primarily failed operative therapy of knee deformity due to incomplete correction and the surgical technique utilized to correct the residual external torsional deformity and dislocation of the patella in a 19year old girl who presented with the typical clinical features of Ellis–van Creveld Syndrome.

Symptomatic calcification of the anterior cruciate ligament: A case report

2011-08-08

Abstract: We report a rare case of symptomatic calcification of the ACL. A 31-year-old man complained of severe knee pain with restriction of knee motion from 30° to 130° for a week. Plain radiographs and multi-planar CT revealed calcification within the intercondylar notch with no osteoarthritic changes. MRI revealed a low signal intensity mass near the intact ACL. The ACL appeared bulged by arthroscopy and white and creamy fluid exuded from the partially excised synovial membrane. Pain subsided immediately postoperatively. Histologically, the calcific deposit near the ACL showed negligible degenerative changes and resembled calcifying tendinitis of the rotator cuff. Although calcific deposits rarely affect the knee joint, calcification of the ACL should be included in differential diagnoses for acute knee pain and restricted range of motion such as mechanical locking. This case illustrates that arthroscopic removal of the deposits can be effective.

Corrigendum to “Translational and rotational knee joint stability in anterior and posterior cruciate-retaining knee arthroplasty” [The Knee 18 (2011) 491–495]

JiaHsuan Lo, Otto Müller, Torsten Dilger, Nikolaus Wülker, Markus Wünschel — 2011-11-28

The editor regrets that this paper was published erroneously as a case report. It is in fact an original article.

Corrigendum to “The early results of gender-specific total knee arthroplasty in Thai patients” [The Knee 18 (2011) 483–487]

Aree Tanavalee, Thana Rojpornpradit, Sukree Khumrak, Srihatach Ngarmukos — 2011-11-21

The editor regrets that this paper was published erroneously as a case report. It is in fact an original article.

Corrigendum to “Early complications of medial opening wedge high tibial osteotomy using autologous tricortical iliac bone graft and T-plate fixation” [The Knee 18 (2011) 278–284]

2011-07-25

The editor regrets that this paper was published erroneously as a case report. It is in fact an original article.

British Association for Surgery of the Knee

2012-06-01

Instructions for Authors

2012-06-01