Background: The reported prevalence of hip pain in patients with severe cerebral palsy has varied widely. It is unclear whether surgical treatment is indicated for progressive hip subluxation in immature patients with severe involvement. In the present study, we evaluated seventy-seven adults who were profoundly affected with cerebral palsy to determine if either spastic hip displacement (subluxation or dislocation) or osteoarthritis was associated with hip pain and/or diminished function.

Methods: Data regarding the medical history, level of function, pain, and use of analgesics were obtained from a review of medical records and from caregiver interviews. The range of motion of the hip, the degree of spasticity, the presence of pressure ulcers, and changes in vital signs as well as in the Face, Legs, Activity, Cry, and Consolability behavioral pain score were documented. Radiographs of the pelvis and spine were blindly evaluated for evidence of osteoarthritis and subluxation or dislocation. Statistical analysis was performed in order to identify associations between the medical history, the physical examination findings, and the radiographic measurements.

Results: The study group included seventy-seven adult subjects (thirty-eight men and thirty-nine women) with a mean age of forty years. Twenty-three (15%) of the 154 hips in these subjects were dislocated, eighteen (12%) were subluxated, and thirty-five (23%) had radiographic evidence of osteoarthritis. Twenty-eight (18%) of the 154 hips were definitely painful, and sixty-nine (45%) were definitely not painful. Increased hip pain and problems with perineal care were noted in patients with decreased hip abduction (<30°) (p = 0.01), windswept hip deformities (p = 0.02), and flexion contractures of >30° (p = 0.07). Increased spasticity was associated with higher rates of osteoarthritis, dislocation, pain, and pressure ulcers. Spastic hip subluxation or dislocation was significantly associated with osteoarthritis (p = 0.0001), but not with hip pain. There was no association between radiographic evidence of osteoarthritis and hip pain.

Conclusions: Neither hip displacement (i.e., subluxation or dislocation) nor osteoarthritis was found to be associated with hip pain or diminished function. Because the prevalence of hip pain is low and is not associated with hip displacement or osteoarthritis, we suggest that surgical treatment of the hip in severely affected patients be based on the presence of pain or contractures and not on radiographic signs of hip displacement or osteoarthritis.

Level of Evidence: Prognostic study, Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.