We studied the effect of a limited range of motion (ROM) of the hip joint on the final outcome in LCP disease.

ROM data obtained during the initial 3 years after diagnosis in unilaterally involved 325 pillar B or C hips (bone age≥6 years, average age at induction: 7.9 years) were studied. The non-surgical treatment group included: a) no treatment (23), b) brace (113), and c) ROM exercise (70). The surgical treatment group included: a) femoral osteotomy (49), and b) Salter innominate osteotomy (70). We assessed the relationship between the limited ROM and the Stulberg outcome.

In the non-surgical treatment group, those patients who had never experienced limited motion below 110° or 100° of flexion, below 20° or 10° of abduction, and below 10° of adduction, were significantly associated with a good Stulberg outcome (p<0.05). Using these reduced ROM parameters in combination, as a single factor, outcome prediction was possible in 44% of cases. No correlation was found in surgically treated patients.

Our results support that ROM is an important prognostic factor in the non-surgical treatment group. Surgical procedures seem to change the biomechanical status of the hip joint in Perthes disease, thereby affecting the ralationship between ROM and Stulberg outcome.