Serum 25-hydroxy-calciferol level and failed back surgery syndrome.

PURPOSE: To assess the association of serum 25-hydroxy-calciferol levels with pain and low back function in patients with failed back surgery syndrome.

METHODS: Records of 6 men and 3 women aged 25 to 54 (mean, 39.2) years who had failed back surgery syndrome after pedicular screw and rod instrumentation for lower lumbar degenerative diseases were reviewed. They had moderate-to-severe pain (visual analogue scale [VAS] score of >6) and low back function disability (Japanese Orthopaedic Association [JOA] back score of <10). In all patients, the serum 25-hydroxy-calciferol level was <30 ng/ ml, indicating vitamin D deficiency. Vitamin D2 (20 000 IU per day) was given for 10 days, and vitamin D3 (600 IU per day) was given for maintenance. Patients were followed up at months 3 and 6. Three men and 4 women aged 27 to 55 (mean, 41.3) years who were age- and disease-matched but achieved good outcomes (VAS score of 0-1 and mean JOA low back score of 14.7) were used as indirect referents. All 7 matched patients except one had a normal serum 25-hydroxy-calciferol level (mean, 40.6 ng/ml).

RESULTS: In the 9 patients with failed back surgery syndrome, the mean duration of chronic pain was 2.6 years; the mean VAS score for pain was 7.7; the mean JOA low back score was 7.6; the mean number of reoperations was 2.2; and the mean serum 25-hydroxy-calciferol level was 17.0 ng/ml. Two male patients had grade-IV motor weakness and decreased sensory function based on the pin prick test. One patient had a history of prolonged (>3 months) antibiotic use after primary surgery, but had no evidence of infection. Six months after vitamin D2 and vitamin D3 supplementation, the mean serum 25-hydroxy-calciferol level improved significantly (17.0 vs. 42.5 ng/ml), as did the mean pain score (7.7 vs. 4.2) and mean JOA back score (7.6 vs. 11.1). Seven of the patients had a pain score of <6 and a JOA back score of >10, the remaining 2 patients had neurological deficits and only slight improvement.

CONCLUSION: Vitamin D supplementation may be used as an adjuvant treatment for patients with failed back surgery syndrome.