The genesis of Perthes' disease: does it lie in hips with reduced ranges of movement?

Abstract

Noting that Perthes' disease is relatively common in Caucasian British children compared with black African children, this study was carried out to compare the range of hip movements in a series of 100 normal Ghanaian children and 182 normal British children, between 5 and 6 years of age. A significantly increased range of movement was found in the African group in all parameters, (P<0.001). The changes were even more marked when sex was taken into consideration, female children having a much bigger range of movement than the males in both racial groups. The unaffected hips in a series of 51 Caucasian children presenting with unilateral Perthes' disease were then analysed and were found to have a reduced range of movement compared with normal, in flexion, abduction, internal rotation in flexion and external rotation in extension (P<0.001). It is suggested that one of the reasons why some hips are vulnerable to Perthes' disease could be a preexisting restricted range of movement, which renders them more susceptible to strain injuries.