[Experimental biomechanical study of the advancement of tibial tuberosity]

In 1963 P. Maquet suggested tibial tuberosity advancement as a therapeutic solution for patellofemoral arthrosis, but the fiability of the operation remains controversial. An advancement of the tibial tuberosity by 1.5 centimeter, with and without bilateral retinacular release, was performed on non arthrosic knees of fresh cadavers and on knees presenting medial, lateral or bipolar patellofemoral arthrosis. The joints were tested with flexion ranging from 10 to 70 degrees. The study concentrated on contact areas, pressures and patellofemoral forces analysis using an original and efficient measuring system. The pressure sensitive film used was the Fuji Prescale Film. The study showed that, on non arthrosic knees, the patellofemoral contact was not modified to any significant extent by advancing the tibial tuberosity. In cases of bipolar patellofemoral arthrosis reduced pressures were noted. On the lateral patellofemoral arthrosis experimental model, the tibial tuberosity advancement was efficient as it allowed a 50 per cent reduction in pressure at 10 to 30 degrees of flexion and a 20 per cent reduction at 40 to 50 degrees of flexion and a 20 per cent reduction at 40 to 50 degrees of flexion. In all cases, the best results were obtained from tibial tuberosity advancement associated with bilateral retinacular release. These results indicate that tibial tuberosity advancement may have beneficial effects in cases of lateral and bipolar patellofemoral arthrosis.