The importance of an intact abdominal musculature mechanism in maintaining spinal sagittal balance. Case illustration in prune-belly syndrome.

Methods: A rare case of thoracic hypokyphotic deformity secondary to prune-belly syndrome is presented. Objective: To discuss the role of an intact abdominal musculature mechanism in maintaining spinal sagittal balance, and to present a case illustration of prune-belly syndrome.

Background: There has been an ongoing debate concerning the integrity of the abdominal musculature unit in maintaining spinal support and stability. It is now believed that intra-abdominal pressure hitherto generated plays an important role in the stabilization of the spine. Congenital aplasia of the abdominal musculature, termed prune-belly syndrome, might therefore result in the loss of spinal function and stability. The literature also is reviewed for the incidence of spinal deformities related to this condition.

Methods: A unique case of prune-belly syndrome in a 33-year-old man with congenital aplasia of the abdominal musculature is presented.

Results: The patient exhibited loss of the spinal sagittal balance, with resultant development of a thoracic hypokyphotic deformity and thoracolumbar scoliosis.

Conclusions: Scoliosis appears to be the most commonly reported spinal deformity. Unequal compressive forces on the vertebral endplates may be the proposed mechanism for the spinal deformities. Compensatory lumbar paraspinal overactivity resulting from the inability to generate normal intra-abdominal pressures because of a deficient abdominal wall musculature mechanism seems to be the plausible explanation for the observed thoracic hypokyphatic deformity.