Quadriceps pull test: an outcome predictor for lateral retinacular release in recurrent patellar dislocation.

Recurrent dislocation of the patella is a disorder with a complex aetiology. Several surgical procedures have been recommended for its correction, but there are few clinical or radiological guidelines to facilitate the selection of a particular procedure. The results of treating a series of 29 knees are presented with a follow-up of at least 2 years. A significant correlation has been found between the horizontal movement of the centre of the patella on quadriceps contraction (quadriceps pull test) and surgical outcome when lateral release alone is selected for the correction of recurrent patellar dislocation.