The Insall-Salvati method of assessing the position of the patella was
applied to four groups of patients:normal patients, and those with
dislocation of the patella, chondromalacia of the patella, and apophysitis
of the tibial tubercle. The ratio of patellar length to tendon length was
1.0 in the normal patients, 0.8 in the patients with dislocations, 0.86 in
those with chondromalacia, and 1.2 in those with apophysitis of the tibial
tubercle. Patella alta may be an important cause of dislocating patella and
of chondromalacia patellae. The significance of the patella infera found in
the Osgood-Schlatter lesion may be one of either cause or effect.