Traumatic hip dislocation in children. Long-term followup of 42 patients.

To assess the impact of traumatic hip dislocations in the skeletally immature patient, 42 children younger than 16 years of age (average age, 9 years 10 months) who were treated at the authors' institution were studied. Data were collected from charts and radiographs and by completion of questionnaires. The average followup after injury was 10 years 1 month. The majority of dislocations (64%) were attributable to low energy injuries. Ipsilateral fractures about the hip occurred in 17% of patients. Avascular necrosis of the femoral head developed in 12% of patients, with the amount of time spent dislocated being the only statistically proven risk factor. Patients whose reduction was delayed greater than 6 hours had a 20 times higher risk of having avascular necrosis develop compared with patients whose hips were reduced in 6 hours or less. The use of computed tomography for joint asymmetry of 3 mm or greater and omission of bone scan screening were supported by this study. Functional outcomes were very good in this series with 95% of patients suffering mild (usually weather related) or no pain and 95% of patients suffering mild pain (intermittently noticeable) or no limp. A large percentage of the patients (78%) continued to participate in high demand activities such as football, soccer, and basketball.