Posterior lumbar interbody fusion for dysplastic lumbar spondylolisthesis with high-grade slippage in two adolescent siblings: two case reports

Lumbar spondylolisthesis is reported to present with a familiar pattern, with the dysplastic type of spondylolysis being minor but more hereditary than the isthmic type. Siblings presenting during adolescence with neurological symptoms owing to high-grade dysplastic-type spondylolisthesis are rare.

The older brother suffered from left leg pain and numbness and dysesthesia of the right posterior thigh and calf and could not walk without a crutch at the age of 15 years. He had canal stenosis with disc bulging and dysplastic bilateral facet joint at L5/S1. The L5 vertebral body was slipped anterior downward to S1, with a round-shaped S1 cranial endplate. We diagnosed dysplastic-type spondylolisthesis and performed posterior lumbar interbody fusion at L5/S with mild reduction and sublaminar wiring at L4/5. The younger brother had no neurological symptoms at age 14 years but suffered from bilateral lower leg numbness at age 18 years. He had canal stenosis with disc bulging at L4/5 and L5/S1 and dysplastic bilateral facet joint at L5/S1 with right pars defect. The L5 vertebral body was vertically displaced anterior to the S1 vertebral body, with an S1 round-shaped cranial endplate. We diagnosed dysplastic-type spondylolisthesis, and posterior lumbar interbody fusion at L4/5 and L5/S with reduction was performed. Their neurological symptoms of the lower legs disappeared, and interbody bone fusion was obtained.

The surgical technique for high-grade dysplastic spondylolisthesis remains controversial in terms of in situ fusion versus reduction. We recommend that surgery be performed promptly at the end of bone maturation because neurological symptoms often appear at the end of bone maturation. Because high-grade slips are rare but siblings may be present, the sibling should also be screened when dysplastic spondylolisthesis is detected.