[Developmental lumbar stenosis in eleven French Antilles patients].

PURPOSE OF THE STUDY: Developmental lumbar stenosis is a rare entity, exceptionally described in the literature. No study has been directly devoted to this condition. The purpose of the present study was to examine specific features, particularly clinical and anatomic expression, observed in a series of operated patients.

MATERIAL AND

METHODS

Eleven patients from the French Antilles were treated for developmental lumbar stenosis between 1996 and 2000. The Verbiest criteria were used to define canal narrowness. Signs of degeneration and presence of discal herniation were exclusion criteria. Epidemiological and clinical data were collected for the 11 patients. The degree of sagittal stenosis (fixed diameter at the bone level and mobile diameter at the discal level) was measured on computed tomography images. Transverse stenosis was determined by measuring the interpedicular and interapophyseal distances. Lateral stenosis was determined by measuring the depth of the recessus.

RESULTS

These patients were young (mean age 42.4 years). Most of the clinical signs were monoradicular. Discal level stenosis predominated, generally at level L4-L5. It was generally central and lateral, sagittal and transverse. The interpedicular distance was the only diameter that remained within normal limits. Soft tissues (yellow ligaments and joint capsules) played an important role in the stenosis.

DISCUSSION: The rare reports of developmental lumbar stenosis describe decompensated stenosis due to discal herniation in the adolescent. Developmental lumbar stenosis is considered to be a genetic disease and its particular high frequency in the French Antilles favors this hypothesis. The stenosis results from bony (short pedicles, hypertrophic lateral masses) and ligament (hypertrophy of the yellow ligament and joint capsules) structures.

CONCLUSION

Developmental lumbar stenosis produces a global (sagittal, transverse, central, lateral) narrowing of the lumbar canal where soft tissue structures apparently play a greater role than usually thought. A prospective study examining the impact of ethnic origin is required to analyze the genetic hypothesis.