Incidence and degree of hip subluxation/dislocation in children with spinal cord injury.

BACKGROUND/OBJECTIVES: The purpose of this study was to verify the incidence and degree of hip subluxation/dislocation in children with spinal cord injury (SCI) and determine the association between age of injury and hip subluxation/dislocation. METHODS: All children from our SCI database with complete data through 2001, who had follow-up of > 2 years and were at least 14 years of age at follow-up, were included in the study. Hip subluxation was defined as a migration index (MI) > 20%. The medial joint space (MJS) was measured and considered abnormal if > 7 mm. The patients were divided into 2 groups: those < or = 10 years of age at the time of injury (group 1) and those > 10 years of age (group 2). There were 62 patients included in the study: 29 in group 1 and 33 in group 2. The mean age at the time of injury was 4.6 years for group 1 and 14.3 years for group 2. RESULTS AND CONCLUSION: Forty-eight percent of patients had at least one hip with subluxation/dislocation: 93% in group 1 and 9% in group 2. The mean MI (for those that were abnormal) was 44% in group 1 and 25% in group 2. The MJS was abnormal in 78% of hips in group 1 and 38% in group 2. Thirteen patients in group 1 and 1 patient in group 2 underwent surgery to better contain the hip. Numerous other radiographic hip irregularities were identified. This study demonstrates a high rate of hip subluxation/dislocation in children with SCI who had onset of injury before 10 years of age.