Isokinetic knee extension strength and pain before and after advancement osteotomy of the tibial tuberosity.

In 30 patients with patellofemoral chondromalacia and osteoarthrosis the maximal isokinetic knee extension strength was measured. The pain evoked during the recordings was rated on a nine-grade scale. The peak extension torques were markedly lower than in the non-diseased knee and in a reference group of healthy volunteers. Twenty months after advancement of the tibial tuberosity, the muscle strength was significantly increased and pain significantly alleviated, well parallelling the clinical improvement. Intra-articular anaesthesia almost instantaneously increased the knee extension torque considerably, although knee pain was unchanged.