Perthes' disease--a classification based on the extent of epiphyseal and metaphyseal involvement.

A tentative classification of Perthes' disease according to the extent of epiphyseal and metaphyseal involvement in lateral radiographs of the hip was applied to 61 hips in 55 patients. Forty-four hips were treated by containment (Tachjian's trilateral socket hip abduction orthosis) and 17 hips were treated surgically either by intertrochanteric or sub-trochanteric osteotomy. The results correlated well with the classification of the authors. The greater the extent of involvement of the epiphysis and metaphysis, the severer the resulting deformity. The choice of method of treatment is also discussed. It is concluded that this classification may be of prognostic value and may be useful to differentiate atypical cases.