Vitamin D insufficiency in patients with THA: prevalence and effects on outcome.

backgroundThe consequences of vitamin D insufficiency in the elderly remain controversial. The prevalence and potential effects of its chronic insufficiency on quality of life and physical function in patients undergoing THA have received little attention. QUESTION/PURPOSES: We determined (1) prevalence of preoperative vitamin D insufficiency in patients undergoing THA and (2) relationships of insufficiency to patient-perceived outcomes (PPOs) and hip scores.

methodsWe retrospectively reviewed 62 consecutive patients who underwent 66 primary THAs. We excluded two patients with missing data and the second hip of bilateral THAs, leaving 60 patients (60 hips) for final inclusion. Based on preoperative plasma 25-hydroxyvitamin-D3 levels, patients were retrospectively assigned into a normal or insufficient group. We used two different thresholds (20 and 30 ng/mL) to define insufficiency; groups were set twice. We compared demographics, BMI, American Society of Anesthesiologists score, Charlson Comorbidity Index; albumin, transferrin, calcium levels; and total lymphocyte count between groups. The insufficient group had a higher mean BMI with the 20-ng/mL cutoff but not with the 30-ng/mL cutoff. We compared the 20-ng/mL cutoff groups (adjusting for BMI) and the 30-ng/mL cutoff groups in terms of preoperative and postoperative Quality of Well-being Scale, SF-36, WOMAC, Harris hip, and Merle d'Aubigné-Postel scores. Mean followup was 11 months (range, 3-24 months).

resultsThe prevalence of vitamin D insufficiency was 30% (using 20 ng/mL) and 65% (using 30 ng/mL). Preoperative and postoperative Harris hip and Merle d'Aubigné-Postel scores were lower in patients with insufficiency using 30 ng/mL. No differences in PPOs or hip scores were found using 20 ng/mL.

conclusionsHypovitaminosis D was common in patients with THA and associated with lower hip scores. Standardization of the definition of hypovitaminosis D is urgently needed so that further studies can properly evaluate its real prevalence, potential negative effects on function, and therapeutic effects of reversing insufficiency before THA.