Association of Vitamin D Deficiency With Distal Biceps Injury: A Retrospective Analysis of 336,320 Patients.

Background: This study explores the association between vitamin D deficiency and distal biceps tendon injuries, illustrating that, although vitamin D deficiency is associated with prolonged hospital stays and various musculoskeletal problems, its connection to distal biceps tendon injuries is unknown.

Hypothesis: Vitamin D deficiency is associated with an elevated risk of distal biceps injury but not with increased rates of subsequent surgery or revision surgery.

Study Design: Case-control study.

Level Of Evidence: Level 3.

Methods: A 1:1 matched retrospective comparative study of 336,320 vitamin-D-deficient patients was performed using PearlDiver data (between January 1, 2011 and October 31, 2018). Cohorts, with a mean age of 55.7 ± 13.2 years, underwent multivariate logistic regression to calculate distal biceps tendon injury and surgical repair incidence according to age and sex, while controlling for demographics and comorbidities.

Results: The 1-year incidence of distal biceps tendinopathy in vitamin-D-deficient patients was 118 per 100,000 person-years (95% CI) compared with 44.3 per 100,000 person-years in matched controls. Male patients with vitamin D deficiency were at a greater risk for distal biceps tendinopathy after 1 and 2 years (adjusted odds ratio [aOR] = 2.81, 2.08-3.83; aOR = 2.80, 2.21-3.56). Female patients were also at a greater risk after both years (aOR = 1.69, 1.27-2.27; aOR = 1.57, 1.26-1.96). Vitamin D deficiency was not associated with an elevated risk of surgical repair or revision surgery.

Conclusion: In a nationwide cohort, a diagnosis of vitamin D deficiency elevated the risk of distal biceps tendinopathy but did not raise the rate of surgical repair or revision. As a result, prevention strategies in the form of vitamin supplementation should be increased for athletes.Clinical Relevance: These findings emphasize the clinical relevance of monitoring vitamin D levels in patients at risk for musculoskeletal injuries, and providing adequate care to those involved in high-demand physical activities.Strength of Recommendation: B.