Spinal canal stenosis in adult with hypophosphataemic vitamin D-resistant rickets

Paravertebral ligament ossification in vitamin D-resistant rickets: incidence, clinical significance, and genetic evaluation

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

The objective of this study was to analyze the cases of paravertebral ossification in vitamin D-resistant rickets (VDRR) and elucidate its incidence and clinical significance, and report specific genetic mutations uniquely associated with this phenomenon.

SUMMARY OF BACKGROUND DATA

Paravertebral ligament ossification has been described in VDRR in a few cases previously. However, supraspinous and interspinous ligament ossification has so far not been described to occur in association with VDRR. We reviewed 6 cases of paravertebral ligament ossification with the added feature of supraspinous and interspinous ligament calcification.

METHODS

Forty-four patients with clinical, radiological, and biochemical diagnoses of VDRR, who were positive for mutations in the PHEX gene, were screened for the presence of paravertebral ossification with plain radiographs and computed tomography/magnetic resonance imaging if necessary. This was correlated with the severity of disease, and we looked for specific genetic mutations.

RESULTS

Six patients had paravertebral ligament ossification, which included supraspinous and interspinous ligament ossification. These patients had a more severe systemic disease, with all patients requiring at least 1 surgery for deformity correction of the limbs, with a total of 10 surgical procedures performed in these 6 patients. c.1601C>T, c.1699C>T, c.1363G>T, and c.466_467insAC were the genetic mutations associated with these cases.

CONCLUSION

The spinal changes with paravertebral ligament ossification in VDRR were described in this study. Four different gene mutations related to the PHEX gene were detected in them. The presence of these changes was suggestive of a more severe systemic disease.

Acute neurologic deterioration after surgical treatment for thoracic spinal stenosis

Spondylotic changes in the thoracic spine resulting in a myelopathic syndrome is a rare condition. Surgical treatment consists of removal of the hypertrophied ligaments, facet joints and laminae (laminectomy). In this report, we review our experience in treating 12 cases of thoracic spinal stenosis (TSS). From 1989-1998, we identified 12 surgical cases treated by the Department of Neurosurgery at Temple University Hospital. For this report, we reviewed both inpatient and outpatient records and radiographic studies. We also reviewed the world's literature regarding this entity. After reviewing our own cases of TSS and the world's literature, we identified a higher than expected incidence of acute neurologic deterioration (AND) after surgical treatment of TSS (14.5%). This incidence is compared to an expected incidence of AND (0-5.5%) after laminectomy for cervical spinal stenosis (CSS). The seemingly higher incidence of AND after surgical treatment of TSS has implications for discussion of risks with patients undergoing surgical treatment.

Thoracic spinal stenosis in two brothers due to vitamin D-resistant rickets

X-linked hypophosphataemic vitamin D-resistant rickets is a rare cause of spinal canal stenosis. Two brothers with this condition presented in adulthood with thoracic myelopathy due to spinal canal stenosis. Both were treated by laminectomy using diamond-tipped burrs, with symptomatic improvement.

Spinal canal stenosis with hypophosphatemic vitamin D-resistant rickets: case report

A 42-year-old woman with sex-linked hypophosphatemic vitamin D-resistant rickets presented with a 6-month history of progressive weakness and numbness in her lower extremities. Radiological studies revealed severe spinal canal stenosis extending from levels T4 to T10. Her symptoms improved markedly after extensive thoracic laminectomies.

The lumbar spinal canal in hypophosphataemic vitamin D-resistant rickets

Lumbar spine radiographs of 17 adult patients with hypophosphataemic vitamin D-resistant rickets have been examined and measured in their anteroposterior and transverse dimensions. Comparison of these measurements with those of a group of normal individuals showed the HPR patient group to have narrower spinal canals in both diameters. No differences were found between males and females in either group. The lumbar spinal canal stenosis in adult HPR patients may make them more susceptible to spinal cord compromise from space occupying lesions within the canal, causing back pain and lower limb weakness for which surgical intervention may be indicated.