Role of Pre-operative Correction of Vitamin D3 Deficiency in Controlling Post-operative Bone Pain after Unicompartmental Knee Arthroplasty.

Introduction: Hypovitaminosis D plays an important role in post-operative bone pain and muscle strength in arthroplasty surgeries. Its role in unicompartmental knee arthroplasty (UKA) has not been elucidated yet. The objective of this study was to determine the impact of hypovitaminosis D and its correction on post-operative bone pain after UKA.

Materials and methods: A prospective cohort study involving 240 patients undergoing mobile-bearing medial UKA was conducted. Group A (na=80) received postoperative correction of Vitamin D3 Deficiency (VDD), Group B (nb=80) received pre-operative correction of VDD, while Group C (nc=80) had normal Vitamin D3 levels to begin with (≥30ng/ml). Correction was done by three doses of intramuscular injection of 600,000 IU Arachitol® (Vitamin D3) given at an interval of one week each. All groups were matched for demography and outcome measures. The level of bone pain by checking for tibial shin tenderness quantified by the visual analog scale (VAS) and evaluated pre-operatively, and at 2, 4, 6 and 12 weeks post-operatively.

Results: Group B and C showed similar post-operative trends and remained significantly superior to Group A till the 6th-week follow-up. The biostatistical difference between Group A and the other two groups started decreasing after the completion of post-operative correction regime as noticed on the 6th-week follow-up. By 12 weeks post-operatively, all three groups had similar levels of bone pain.

Conclusion: Vitamin D3 serves as an important preoperative investigation in patients undergoing UKA as it is a modifiable risk factor affecting post-operative bone pain. Its correction pre-operatively gives excellent post-operative pain control.