The effect of anterior displacement of the tibial tuberosity in idiopathic chondromalacia patellae: a prospective randomized study.

In 42 patients with idiopathic chondromalacia patellae, the effect of anterior displacement of the tibial tuberosity was evaluated in a prospective and randomized study. The operation performed was a modified Bandi procedure, and it resulted in significant relief of the patellofemoral pains, compared with the effect of a standard shaving procedure. Shaving alone was done in 22 patients of whom 6 (27 per cent) were classified as good, a result which may have been due to the placebo effect. In another 20 patients shaving was combined with anterior displacement of the tibial tuberosity resulting in pain relief in 18 (9 degrees per cent). The lack of unambiguously good results may be due to the fact that, although an anterior displacement reduces the retropatellar pressure, it cannot by itself compensate for an abnormal, dynamic tracking pattern of the patella.