A prospective clinical study was done for quantitative examination of
motion of the hip, gait, and proximal femoral remodeling after in situ
fixation of a slipped capital femoral epiphysis. In situ fixation was
performed in forty-five consecutively treated patients (fifty-six hips).
Thirty-nine (87 per cent) of the patients returned for examination two
years after treatment. The greatest percentage of motion of the hip
returned within six months after treatment. Despite loss of internal
rotation of the hip, the mean foot-progression angle was 10.8 degrees.
Radiography and computerized tomographic scanning revealed minimum change
in the relationship of the femoral head to the femoral shaft and no change
in the neck-shaft angle. Motion returned despite minimum osseous
remodeling. The early return of motion (in the first three months) may have
been due to relief of pain, spasm, and synovitis, while soft-tissue
stretching and resorption of bone in the anterolateral part of the femoral
neck may have accounted for the remainder of the increase in internal
rotation.