OBJECTIVE: To determine the prevalence of low serum level of vitamin D in patients before total hip arthroplasty and its relationship with the hip function scores.

METHODS: Forty-eight hips from 48 patients undergoing primary hip arthroplasty from July 2013 to August 2014 in the First Affiliated Hospital of Suzhou University were enrolled. According to the serum level of vitamin D, patients were assigned to low-level (< 20 μg/L) and high-level (20 ≥ μg/L) groups. The general information of patients, the hip function scores before and after replacement at the last follow-up in the two groups were observed and compared. The relationship between the serum level of vitamin D and the hip function scores before and after replacement was analyzed by multiple linear regression analysis. And the average follow-up was 12 months (11-14 months).

RESULTS AND CONCLUSION: (1) The incidence of low vitamin D level was 82% (20 ng/mL serving as standard). (2) Compared with patients with high vitamin D level, patients with low level of vitamin D had lower preoperative Harris scores and Merle D´Aubigne-Postel score (P < 0.05), and also at the last follow-up (P < 0.05. (3) Based on the preoperative and postoperative Harris, the multiple linear regression analysis showed that there was a positive correlation between the level of vitamin D and Harris score both preoperatively and postoperatively (P < 0.05). (4) These results suggest that there is a higher incidence of low level of vitamin D in patients undergoing arthroplasty, and hip function scores before and after replacement in patients with low level of vitamin D are lower than the high level patients. Moreover, there is a positive correlation between the level of vitamin D and the hip joint function scores. Therefore, it is advisable to supplement vitamin D and calcium preoperatively, and the level of vitamin D will be helpful for disease assessment and prognosis.

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程