Three Dimensional CT-based Virtual Patellar Resection in Female Patients Undergoing Total Knee Replacement: A Comparison between Tendon and Subchondral Method

ABSTRACT

BACKGROUND: Due to its small size, variable shape, and lack of distinct anatomical landmarks, osteoarthritic knees make a precise patellar resection extremely difficult. METHODS: We performed virtual patellar resection with digital software using three dimensional computed tomography scans of knees from 49 patients who underwent primary total knee replacement at our hospital. We compared 2 commonly used resection methods, the tendon method (TM) and the subchondral method, to determine an ideal resection plane with respect to the symmetry and thickness of the patellar remnant. RESULTS: The TM gave a thicker resected patella, and a less oval cut surface shape, which gives better coverage for a domed prosthesis. Both methods, however, gave a symmetric resection both superior-inferiorly, as well as mediolaterally. CONCLUSIONS: Although TM appears statistically better with respect to the thickness and cut surface shape, only further intraoperative studies with long-term clinical follow-up may provide us with the most appropriate patellar resection method.