SYMPTOMATIC HIP SUBLUXATION FOLLOWING SPINAL STABILISATION FOR DUCHENNE MUSCULAR DYSTROPHY

Abstract

This is a retrospective study describing four patients who developed symptomatic subluxation of the hip after stabilisation to the pelvis for myopathic scoliosis in Duchenne Muscular Dystrophy (DMD).

Fusion to the pelvis is recommended for treatment of scoliosis in DMD. Non-spinal extra-pulmonary complications following this have not been described.

4 patients (average age: 14 years) out of a cohort of patients who have undergone spinal stabilisation for DMD between 1991 and 1998 developed symptomatic subluxation of the hip at an average of three months after fusion from the upper thoracic spine to the pelvis. All four had pain and three noticed clicking in the hip.

X-rays revealed subluxation of the hip in all patients, and conservative treatment by adjustment of seating position in the wheelchair was successful in reducing the symptoms in all patients.

Flexion-abduction contractures of the hip, which are a feature of DMD, are known to cause uncovering of the contralateral hip. We postulate that the spine compensates for this uncovering to a large degree, and that spinopelvic fusion for scoliosis in patients with pre-existent abduction contractures negates the capacity of the spine to provide compensation. This leads to uncovering of the hip with the lesser degree of contracture, and the resultant symptoms.

We recommend screening for, and treatment of, flexion-abduction contractures of the hip in all patients undergoing spinal fusion for DMD, to avoid the possibility of development of symptomatic subluxation of the hip.