Abstract
ObjectiveTo assess the difference between the posterior condylar angle (PCA) and the mechanical lateral distal femoral angle (mLDFA) in the osseous and cartilaginous contours in a non-arthritic Chinese population.MethodsComputed tomography (CT) and magnetic resonance imaging (MRI) were obtained from 83 patients with knee injuries before arthroscopy, and femur and distal femoral cartilage three-dimensional (3D) models were constructed. The 3D cartilage model was arranged to share physical space with the 3D femoral model, and then PCA and mLDFA were measured on the osseous and cartilaginous contours, respectively. The differences between the measurements with and without cartilage were evaluated.ResultsThe average PCA with cartilage was 2.88 ± 1.35° and without was 2.73 ± 1.34°. The difference was significant in all patients and females but not in males. The average mLDFA with cartilage was 84.73 ± 2.15° and without cartilage was 84.83 ± 2.26°, but the difference was statistically insignificant in all groups.ConclusionPCA on the osseous and cartilaginous contours significantly differed with and without cartilage in the female group, suggesting that cartilage thickness should be considered during preoperative femoral rotational resection planning.
Highlights
Correct component implantation is essential for prosthesis survivorship and clinical outcomes in total knee arthroplasty (TKA)
Jang et al indicated that the posterior condyle line (PCL) + 3◦ external rotation method was the most accurate compared to the surgical transepicondylar axis (sTEA) but highly varied among subjects [6] since the posterior condylar angle (PCA) varies remarkably among patients [7]
Okamoto et al found that 2D preoperative planning resulted in the internal rotation of the femoral component, and the clinical and surgical angle values measured based on X-ray and CT slices would be smaller than the 3D measurements, causing internal component rotation [12]
Summary
Correct component implantation is essential for prosthesis survivorship and clinical outcomes in total knee arthroplasty (TKA). Several methods have been proposed to perform distal femoral resection, including the surgical transepicondylar axis (sTEA), Whiteside’s line, posterior condyle line (PCL) + 3◦ external rotation for rotational alignment correction, and 5–7◦ valgus relative to the anatomic axis for improving coronal alignment. The sTEA is the most approximative flexion axis of the knee, and the symmetric posterior condylar femoral prosthesis implanted parallel to the sTEA is thought to achieve optimal rotational alignment. Since the sTEA had low intra- and interobserver reproductivity and the anatomic landmarks were difficult to identify during the operation, the PCL + 3◦ external rotation method was used more often in practice [5]. Jang et al indicated that the PCL + 3◦ external rotation method was the most accurate compared to the sTEA but highly varied among subjects [6] since the PCA varies remarkably among patients [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
