ORIGINAL ARTICLE   

Journal of Neurosurgical Sciences 2019 February;63(1):36-41

DOI: 10.23736/S0390-5616.16.03846-7

Copyright © 2016 EDIZIONI MINERVA MEDICA

language: English

Vitamin D status in cervical spondylotic myelopathy: comparison of fusion rates and patient outcome measures

Vijay M. RAVINDRA ¹, Jian GUAN ¹, Christopher M. HOLLAND ¹, Andrew T. DAILEY ¹, Meic H. SCHMIDT ¹, Jakub GODZIK ², Robert S. HOOD ¹, Wilson Z. RAY ³, Erica F. BISSON ¹ ✉

¹ Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, USA; ² Department of Neurosurgery, Barrow Neurological Institute, Phoenix, AZ, USA; ³ Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO, USA

BACKGROUND: Patients undergoing elective spinal fusion have an alarming rate of vitamin D deficiency, but its impact on bone fusion and patient outcomes is unclear. We investigated the association of perioperative vitamin D levels, fusion rates, and patient-reported outcome in patients undergoing spinal fusion for cervical spondylotic myelopathy.
METHODS: In this one-year, prospective, single-center observational study, serum 25-OH vitamin D levels were measured perioperatively in adult patients. Serum vitamin D levels <30 ng/mL were considered abnormal. The primary outcome measures were postoperative patient-reported outcomes (Neck Disability Index, Visual Analog Scale, EuroQol EQ-5D-3L, EQ-VAS). Secondary outcome measures were the presence of and time to solid bony fusion, controlling for Body Mass Index (BMI), age, and number of motion segments.
RESULTS: Forty-one of 58 patients (71%) had laboratory-confirmed abnormal vitamin D levels. Patients with low vitamin D were younger (P<0.05) and had a higher BMI (P<0.05) than patients with adequate vitamin D, but the groups were otherwise similar. There were no differences in mean time to fusion between the two groups, but patients with low vitamin D reported more postoperative disability (P<0.05). Multivariate model analysis demonstrated an independent, significant association between normal vitamin D and lower postoperative neck disability index (P=0.05) and EQ-5D-3L (P=0.03).
CONCLUSIONS: Vitamin D deficiency (<30 ng/mL) is highly prevalent in patients undergoing elective spinal fusion for cervical myelopathy. Low vitamin D levels were associated with worse patient-reported outcomes and were an independent predictor of greater disability, which suggests vitamin D supplementation may offer some benefit in these patients.

KEY WORDS: Vitamin D deficiency - Spinal cord diseases - Spinal fusion - Treatment outcome