Hip pain in adolescents with cerebral palsy: a population-based longitudinal study.

AIM: To investigate the prevalence, characteristics, and risk factors of hip pain in adolescents with cerebral palsy (CP) and compare the findings with those of the same individuals 5 years earlier. METHOD: Sixty-seven adolescents (28 females, 39 males; mean age 14y 7mo; SD 1y 5mo; range 12-17y) with bilateral CP, in Gross Motor Function Classification System (GMFCS) levels III to V enrolled in a CP surveillance programme were assessed for hip pain. Their caregivers responded to the questions on the intensity and frequency of hip pain from the Child Health Questionnaire (CHQ) (transformed to CHQ hip pain score; 100 indicates no pain). Interference of hip pain with daily activities and sleep was recorded on numeric rating scales. Hip displacement was measured radiographically by the migration percentage. RESULTS: Twenty-eight participants had 44 painful hips. Their mean CHQ hip pain score was 40 (SD 21.4; range 10-80). Independent risk factors for hip pain, low CHQ hip pain score, and interference with sleep were severe hip subluxation (migration percentage 50-89%) and GMFCS level V. A migration percentage of 50% to 89% was the only independent risk factor for interference with daily activities. Over 5 years, the number of participants with hip pain increased from 18 to 28, while the mean migration percentage of the most displaced hip was unchanged. INTERPRETATION: Our CP hip surveillance programme did not protect the participants against increasing prevalence of hip pain during adolescence. We suggest that surveillance programmes for CP should include guidelines on the characteristics and management of hip pain. WHAT THIS PAPER ADDS: Hip pain prevalence increased in adolescents over a 5-year period in a cerebral palsy surveillance programme. Risk factors for hip pain were Gross Motor Function Classification System level V and severe hip subluxation.