High prevalence and seasonal variation of hypovitaminosis D in patients scheduled for lower extremity total joint arthroplasty.

BACKGROUND

High rates of vitamin D insufficiency and deficiency have been demonstrated in various patient populations, including patients undergoing total joint arthroplasties (TJA). However, the risk factors associated with this condition and its seasonal variation is still to be determined in patients scheduled for elective TJA.

METHODS

We retrospectively identified 226 (116 hips, 120 knees) patients who underwent primary TJA, and had a vitamin D measurement, at a single institution (latitude, 41° 30' N) from 2006 to 2016. Demographics, comorbidities, and perioperative data were collected from electronic medical records. Patients were stratified into vitamin D sufficient (≥30 ng/mL), insufficient (<30 ng/mL), and deficient group (<20 ng/mL). Multivariate regression analyses were used to study the risk factors for vitamin D insufficiency and deficiency.

RESULTS

There were 99/226 (43.8%) patients in the vitamin D sufficient group, 137/226 patients (60.6%) in the insufficient group, of which 61/226 (26.9%) were in the deficient group. On multivariate analysis, an American Society of Anesthesiologists' (ASA) score ≥3 was a risk factor for vitamin D insufficiency (P<0.001), while ASA ≥3 (P<0.001) and younger age (P=0.002) were risk factors for vitamin D deficiency. Vitamin D levels varied between the quarters with lowest level seen in quarter 1 (P=0.015).

CONCLUSIONS

There was an overall high prevalence of vitamin D insufficiency (60%) and deficiency (27%). Due to higher risk of hypovitaminosis D, particular attention should be placed in patients with an ASA score ≥3, and patients scheduled during winter season.