Patella alta and chondromalacia.

The Insall-Salvati (5) method of assessing the position of the patella was applied to 247 male patients made up from five different groups. Three of the groups were Greeks with normal knees (45 patients), knees already operated on for chondromalacia patellae (36 patients) and knees with a clinical diagnosis of chondromalacia patellae (57 patients). The other two groups comprised 58 African negroes and 51 Arabs, in all of whom a clinical diagnosis of chondromalacia patellae had been made. The ratio of the length of the patella to the length of the patellar tendon in the Greeks was 0.982 in the normal knees, 0.96 in the knees after operation and 0.971 in the knees with clinical chondromalacia. The ratio in Africans was 0.904 and in Arabs 0.929. Patella alta was found in 50% of the Greeks who had had operation or clinical chondromalacia, but it was more frequent in the Africans (74.1%) and the Arabs (68.6%). This difference is statistically significant (p less than 0.01 and p less than 0.05 respectively).