Incidence and Size of Fabella in Osteoarthrosis of the Knee.

Abstract

Radiographs of 561 knees were examined to determine the incidence and size of fabella in radiographically normal knees as compared with knees with primary osteoarthrosis.To get an age matched control group, 302 knees from patients greater the 50 years of age were selected.Fabella was present in 144 of 244 (59.0%) primary osteoarthritic knees, and only in 20 of 58 (34.5%) radiographically normal knees (P<0.01).The length of the long axis of faballa averaged 8.5±3.1mm in primary osteoarthritic knees and 6.9±2.06mm in radiographically normal knees (P<0.05). Fabella size tended to increase as the stage of osteoarthrosis became more severe.The presence and size of fabellae may predispose the knee to osteoarthrosis.