Successful recruitment to a feasibility trial investigating if supplementation for Vitamin D deficiency improves outcomes following total hip or knee replacement: The VASO feasibility Trial – early results. (FEGGETTER MEDAL WINNER)

RJM Morrison 1,2, D Bunn 3, WK Gray 3, PN Baker 4,5, C White 4, A Rangan 4,5,6, KS Rankin 2, MR Reed 1,2,5
1 – Department of Orthopaedics, Northumbria Healthcare NHS Foundation Trust, UK
2 – Newcastle University, UK
3 – Research & Development, Northumbria Healthcare NHS Foundation Trust, UK
4 – Department of Orthopaedics, South Tees Hospitals NHS Foundation Trust, UK
5 – Department of Health Sciences, University of York, UK
6 – Faculty of Medical Sciences & NDORMS, University of Oxford, UK

Introduction
190,000 total hip (THR) and knee (TKR) replacements are performed yearly in the UK, but up to 20% of patients remain dissatisfied. Vitamin D deficiency is common, and studies have suggested a link to poor post-operative outcome. To date, nobody has investigated if supplementation is of benefit. 

Methods
Patients undergoing THR/TKR were recruited to this prospective, randomised-controlled feasibility study. Vitamin D level was measured when added to the waiting-list for surgery, and lifestyle and baseline PROM (Oxford hip/knee and EQ-5D scores) questionnaires completed. Those with deficiency (<50nmol/L) were randomised to receive either cholecalciferol supplementation or no treatment. Vitamin D levels were rechecked on the day of surgery, and again at 6-months when post-operative scores were completed. The primary outcome was the feasibility of performing a large multi-centre study, with outcome measures to assess the effect on health-gain. Secondary outcomes included length of stay and complications. 

Results
102 patients were recruited between May and June 2017. 38% had Vitamin D deficiency at baseline. Mean baseline Oxford measures showed lower scores in patients with Vitamin D deficiency compared to those with normal levels. Day of surgery blood testing has been completed, and 6-month follow-up tests are underway, with final data collected in July 2018. 

Conclusion
This is the first interventional trial to investigate if supplementation for deficiency improves outcomes for patients undergoing THR/TKR. Recruitment to the feasibility trial was possible, and the pending results of this trial will inform the design of a larger, multi-centre trial.