In a prospective study of 105 arthrotomies for chondromalacia patellae,
patella alta or an increased Q angle was found in most of the knees and was
considered to be the usual cause of chondromalacia. The chondromalacia on
the patella was usually centrally located with extension equally onto the
medial and lateral facets. Femoral changes were uncommon. Patellar
realignment together with excision of chondromalacic cartilage gave a
satisfactory result in 79 per cent of the eighty-seven knees that could be
followed.