scholarly journals Femoral Component Rotation in Patellofemoral Joint Replacement: A Study Protocol for a Prospective Observational Study

2015 ◽  
Vol 9 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Robin E Westerbeek ◽  
Rosalie P.H Derks ◽  
Bas J.G.L Zonneveld ◽  
Hans-Peter W. van Jonbergen

Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. The short and mid-term outcomes are related to malposition and unexplained pain. Whether external rotation of the femoral component in isolated patellofemoral joint replacement is required is unclear. The primary aim of this study is to determine the CT-measured femoral component rotation of patellofemoral joint replacement relative to the transepicondylar axis. The secondary aim is to correlate the CT-measured femoral component rotation with the clinical outcomes at 1-year follow-up as assessed with the KOOS questionnaire. We designed a prospective observational study with medical research ethics committee and institutional review board approval. A total of 40 patients who will be treated with patellofemoral joint replacement for isolated patellofemoral osteoarthritis will be included. Intra-operatively, rotation of the femoral component will be assessed using anatomical landmarks including the epicondylar axis, Whiteside’s line, and lower leg axis. The aim is to insert the femoral component between 3 and 6 degrees external rotation relative to the transepicondylar axis. Two experienced musculoskeletal radiologists will measure the angle between the transepicondylar axis and the femoral component, two to three days after surgery. The primary outcome is the CT-based femoral component rotation of the prosthesis relative to the transepicondylar axis. The secondary outcome is the patient reported KOOS questionnaire at 1-year follow-up. Successful completion of this study will provide data on the actual amount of femoral component rotation in patellofemoral joint replacement, and its relationship with clinical results. (Netherlands Trial Register NTR4175).

2019 ◽  
Vol 33 (10) ◽  
pp. 971-977
Author(s):  
Diana K. Lee ◽  
Matthew J. Grosso ◽  
David P. Trofa ◽  
Julian J. Sonnenfeld ◽  
H. John Cooper ◽  
...  

AbstractProper femoral component rotation in total knee arthroplasty (TKA) is important, given the prognostic impact of a poorly positioned component. The purpose of this observational study was to determine the incidence of femoral component malrotation using posterior condylar axis (PCA) referencing. A total of 100 knees in 92 patients with varus gonarthritis of the knee undergoing primary TKA using a standard medial parapatellar approach were evaluated intraoperatively. After distal femoral resection, the standard femoral sizing guide referencing the posterior condylar axis was used to set femoral component rotation. This was then compared with both the transepicondylar (TEA) and trochlear anteroposterior axes (TRAx). Disparites were recorded and corrected in line with the epicondylar axis. Rotational adjustment for addition of further external rotation was made in 13 (13.0%) cases. In seven cases, the medial pin sites were raised between 1 and 3 mm, and in six cases, the lateral pin site was lowered between 1 and 3 mm (based on risk of notching the femoral cortex). It is critical to not rely exclusively on the PCA to confirm rotational positioning of the femoral component as predicted by posterior condylar referencing guides. Intraoperative adjustment and confirmation using the TEA and TRAx occurred in 13% of primary TKA cases, which might have, otherwise, had a significant effect on the clinical outcome.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Stefan W. Kreuzer ◽  
Amir Pourmoghaddam ◽  
Kevin J. Leffers ◽  
Clint W. Johnson ◽  
Marius Dettmer

Rotation of the femoral component is an important aspect of knee arthroplasty, due to its effects on postsurgery knee kinematics and associated functional outcomes. It is still debated which method for establishing rotational alignment is preferable in orthopedic surgery. We compared force sensing based femoral component rotation with traditional anatomic landmark methods to investigate which method is more accurate in terms of alignment to the true transepicondylar axis. Thirty-one patients underwent computer-navigated total knee arthroplasty for osteoarthritis with femoral rotation established via a force sensor. During surgery, three alternative hypothetical femoral rotational alignments were assessed, based on transepicondylar axis, anterior-posterior axis, or the utilization of a posterior condyles referencing jig. Postoperative computed tomography scans were obtained to investigate rotation characteristics. Significant differences in rotation characteristics were found between rotation according to DKB and other methods (P<0.05). Soft tissue balancing resulted in smaller deviation from anatomical epicondylar axis than any other method. 77% of operated knees were within a range of ±3° of rotation. Only between 48% and 52% of knees would have been rotated appropriately using the other methods. The current results indicate that force sensors may be valuable for establishing correct femoral rotation.


The Knee ◽  
2018 ◽  
Vol 25 (6) ◽  
pp. 1272-1277 ◽  
Author(s):  
Serajdin Ajnin ◽  
Donald Buchanan ◽  
James Arbuthnot ◽  
Richard Fernandes

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