Article Text
Abstract
Objective To test whether daily high-dose vitamin D improves recovery after unilateral total knee replacement.
Methods Data come from a 24-month randomised, double-blind clinical trial. Adults aged 60 and older undergoing unilateral joint replacement due to severe knee osteoarthritis were 6–8 weeks after surgery randomly assigned to receive daily high-dose (2000 IU) or standard-dose (800 IU) vitamin D3. The primary endpoints were symptoms (Western Ontario and McMaster Universities Arthritis Index pain and function scores) assessed at baseline, 6, 12, 18 and 24 months in both knees, and the rate of falls over 24 months. The secondary outcomes were sit-to-stand performance, gait speed, physical activity and radiographic progression in the contralateral knee.
Results We recruited 273 participants, 137 were randomised to receive 2000 IU and 136 were randomised to receive 800 IU vitamin D per day. 2000 IU vitamin D increased 25-hydroxyvitamin D levels to 45.6 ng/mL and 800 IU vitamin D to 37.1 ng/mL at month 24 (p<0.0001). While symptoms improved significantly in the operated knee and remained stable in the contralateral knee over time, none of the primary or secondary endpoints differed by treatment group over time. The rate of falls over 24 months was 1.05 with 2000 IU and 1.07 with 800 IU (p=0.84). 30.5% of participants in the 2000 IU and 31.3% of participants in the 800 IU group had radiographic progression in the contralateral knee over 24 months (p=0.88).
Conclusions Our findings suggest that a 24-month treatment with daily 2000 IU vitamin D did not show greater benefits or harm than a daily standard dose of 800 IU among older adults undergoing unilateral total knee replacement.
- knee osteoarthritis
- orthopaedicsurgery
- rehabilitation
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Footnotes
Contributors HAB-F designed the trial, is the guarantor, received funding for the trial, wrote the analysis plan, performed statistical analyses and wrote the first draft of the paper. EJO codesigned the trial, supervised the analyses as the head biostatistician and contributed to the first draft of the paper. AE was the coordinating study MD of the trial, contributed to data cleaning and contributed to the first draft of the paper. BD-H contributed to the design of the trial and contributed to the first draft of the paper. KF cleaned the data set, contributed to the first draft of the Methods and Results sections, and reviewed the final draft of the paper. HBS contributed to the design of the trial, was an advisor on the falls outcome and reviewed the final draft of the paper. RR contributed to the design of the trial, was an advisor on the WOMAC pain and function outcomes, and reviewed the final draft of the paper. JH collaborated on the radiological assessment of knee OA in the trial, advised on the radiological outcome and reviewed the final draft of the paper. AvE advised and performed the laboratory analyses and reviewed the final draft of the paper. GF advised on the analyses and adjudication of falls and reviewed the final draft of the paper. UM cleaned the data set, contributed to the first draft of the Methods section and reviewed the final draft of the paper. TG advised on the participant selection for the trial, supervised recruitment at the largest recruitment site and reviewed the final draft of the paper. PB contributed to the design of the trial, was an advisor on 25-hydroxyvitamin D measurements and reviewed the final draft of the paper. SS advised on the analyses of comorbid conditions and reviewed the final draft of the paper. PC-B contributed to data cleaning, advised on the statistical analyses and reviewed the final draft of the paper. RT contributed to the design of the trial and the first draft of the paper. WCW contributed to the design of the trial and the first draft of the paper. DF contributed to the design of the trial, is guarantor, coordinated the radiological assessment and contributed to the first draft of the paper. All authors reviewed and approved the final draft of the paper.
Funding This project was funded by a Swiss National Science Foundation Professorship (Swiss National Science Foundations Professorship Grant PP00B-114864; Bischoff-Ferrari HA) the Velux Stiftung (Grant Number 441; Bischoff-Ferrari HA) and the Baugarten Foundation Center Grant to the Center on Aging and Mobility at the University of Zurich and University Hospital Zurich (Bischoff-Ferrari HA).
Competing interests None declared.
Patient consent Obtained.
Ethics approval The study protocol was approved by the ethical committee of the Canton of Zurich and the Swiss Agency for Therapeutic Products (Swissmedic, regulatory agency of Switzerland).
Provenance and peer review Not commissioned; externally peer reviewed.