How to reduce osteopenia in total knee arthroplasty?

Claude Schwartz

Osteopenia of the front half of the distal femur is a well-known problem after total knee arthroplasty (TKA) with secondary issues after years, especially when must be addressed fractures or revisions for loosening. Stress shielding has been recognized as a cause in different biomechanical studies of the bone. It was logical to look for a solution by changing the design to minimize stress shielding behind the femoral shield. It was proved that radiological measure of bone density was reliable although not so early and accurate as densitometry. We used a shield without posterior fixation of the trochlea in a series of 21 TKA with radiological measures, preoperative, at 3 months and at 5 years. We compared the results with those of a series of classical TKA in the same category of age and sex. The TKA without trochlea posterior fixation presented a significantly reduced osteopenia compared to the classical design of the femoral shield. It seems that the non-fixation of the posterior surface of the trochlea may reduce osteopenia in TKA and so the risk of fractures and complications when revision surgery. 2a.