Cervical spinal cord compression attributable to a calcified intervertebral disc in a patient with X-linked hypophosphatemic rickets: case report and review of the literature

OBJECTIVE AND IMPORTANCE: X-linked hypophosphatemic rickets is a common inherited phosphate-wasting disorder, but it is a rare cause of spinal cord compression. We present the first reported case of a calcified intervertebral disc causing spinal canal stenosis in X-linked hypophosphatemic rickets. CLINICAL PRESENTATION: A 44-year-old woman presented with paresthesia of her left arm and a loss of grip in both hands. Magnetic resonance imaging revealed a calcified intervertebral disc, as well as a posterior osteophytic bar causing marked cervical cord compression at C6/C7. INTERVENTION: An anterior cervical discectomy at C6/C7 and fusion with autologous bone graft were performed. The patient then exhibited significant improvement. CONCLUSION: A review of the 16 published cases demonstrates that thickening of the vertebral laminae, facet joint hypertrophy, and ossification of the intervertebral discs, posterior longitudinal ligament, and/or ligamentum flavum contribute to spinal canal stenosis in X-linked hypophosphatemic rickets. Those changes are caused by the disease itself and are unlikely to be related to long-term vitamin D treatment. Eleven of 16 patients were reported to have experienced favorable outcomes after surgery.