Vitamin D Levels and One-Year Fusion Outcomes in Elective Spine Surgery: A Prospective Observational Study.
Spine (Phila Pa 1976). 2015 Jul 10. [Epub ahead of print]
Ravindra VM1, Godzik J, Dailey AT, Schmidt MH, Bisson EF, Hood RS, Cutler A, Ray WZ.
1Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah
2Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona
3University of Florida School of Medicine, Gainesville, Florida 4Department of Neurosurgery, Washington University in St. Louis, St. Louis, Missouri.
Prospective observational studyObjective. To investigate the association of perioperative vitamin D levels and nonunion rates and time to fusion in patients undergoing elective spine fusion.
SUMMARY OF BACKGROUND DATA:
Although there is a clear link between bone mineral density and the risk of osteoporosis, it is unclear whether low vitamin D levels affect rates and timing of spinal fusion.
Serum 25-OH vitamin D levels were measured perioperatively in adults undergoing elective spinal fusion between 2011 and 2012. Vitamin D levels <20 ng/mL were considered deficient. Univariate and multivariate logistic regression were performed to identify independent predictors of pseudarthrosis/nonunion within a minimum follow-up period of 12 months. Kaplan-Meier analysis was used to compare time to fusion between groups.
Of the 133 patients, 31 (23%) demonstrated vitamin D deficiency. Mean patient age was 57±13 years; 44% were female and 94% were Caucasian. The cervical spine was fused in 49%, the lumbar spine in 47%, and the thoracic spine in 4%. Mean construct length was 2 levels (range 1-16). At 12-month follow-up, 112/133 (84%) patients demonstrated fusion (median time to fusion 8.4 months). Nonunion at 12 months was associated with vitamin D deficiency (20% of patients with adequate vitamin D level vs. 38% of vitamin D-deficient patients, p = 0.063). Kaplan-Meier survival analysis demonstrated time to fusion was significantly longer in the vitamin D-deficient group (12 vs. 6 months, p = 0.001). On multivariate analysis, vitamin D deficiency was an independent predictor of nonunion (OR 3.449, p = 0.045) when adjusted for age, sex, obesity, fusion length, location, graft type, smoking, and bone morphogenetic protein use.
Vitamin D levels may affect nonunion rate and time to fusion. These results offer insight into the importance of the metabolic milieu for bony fusion as well as a potential avenue for therapeutic intervention.
Study was reported in Becker's Spine Review - 5 key points
- 1. There were 31 patients — 23 percent — who had a vitamin D deficiency at the time of surgery. There were 84 percent of the patients who showed fusion eight months after surgery.
- .2. After 12 months, there was an association between non-unions and vitamin D deficiency. Twenty percent of the patients with adequate vitamin D reported non-unions while 38 percent of the vitamin D-deficient patients reported non-unions.
- 3. The time to union was significantly longer — 12 months — for the vitamin D-deficient patients compared with six months for the non-deficient patients.
- 4 The vitamin D deficiency as an independent predictor of non-union held up when adjusting for age, sex, obesity, fusion length, location, graft type, smoking and bone morphogenetic protein use.
- 5. The researchers concluded their "results offer insight into the importance of the metabolic milieu for bony fusion as well as a potential avenue for therapeutic intervention."
Wonder how many years it will take for researchers to consider adding Vitamin D to increase human spinal fusion?
Wonder also if they will try adding Vitamin K2 - which helps build bones. Henry Lahore, Oct 2015
Note: Spinal fusion was increased in rats given vitamin D - Spine April 2015