OBJECTIVETo investigate the mechanism of diabetes insipidus complicated with skeletal fluorosis and the surgical treatment of spinal canal stenosis caused by skeletal fluorosis.

METHODSFrom January 2000 to November 2011, 5 patients with diabetes insipidus complicated with skeletal fluorosis were treated with drug and cervical or thoracic posterior decompression including 2 males and 3 females with age of 35, 45, 47, 49, 55 years old respectively. The symptoms was mainly limb motor sensory disturbance accompanied by polyuria and polyuria. Imaging showed that cervical and thoracic multi-segmental continuous spinal stenosis. It was diagnosed with diabetes insipidus according to the symptoms and laboratory tests. According to the symptoms, the vertebral with problems were located and treated by posterior laminectomy decompression or the expansive open-door laminectomy. The recovery of neurological symptoms were recorded and the operation result were evaluate by JOA score improvement rate.

RESULTSThe wound healed well in 5 cases, and 1 case of cervical axial pain was improved after symptomatic treatment. Five patients were followed up for 2 to 6 years with an average of 4 years. Numbness of limb and weakness symptoms of follow-up patients were significantly improved, muscle strength and acupuncture hypothyroidism were significantly improved compared with preoperative, the JOA score was significantly improved. At the final follow-up, the improvement rate got excellent results in 2 cases, good in 2 and fair in 1.

CONCLUSIONSLong-term high intake of fluoride can cause skeletal fluorosis in patients with diabetes insipidus. The posterior decompression is effective for the majority of spinal canal stenosis caused by skeletal fluorosis.