FOTO Rehab Outcomes Blog

Pre-operative Exercise for Joint Replacements: Is it Worth It?

Written by Selena Horner | Feb 10, 2017 11:00:00 AM

 I'll be the first to disagree with the conclusion.  As we try to do the right thing to be as efficient and effective as possible, we need to think about the data and understand how to interpret the data ourselves.

First of all, I am going to look at the differences between the groups for my thought rationale. We definitively know these groups had osteoarthritis. There is a study sharing minimal detectable change (MDC) for individuals who have osteoarthritis. In one study including patients with knee OA, the MDCs for KOOS Pain were 13.4, for KOOS Symptoms: 15.5, for KOOS ADL: 15.4, for KOOS Sport/Rec: 19.6, and for KOOS QOL: 21.1 (Collins, Misra et al. 2011). If I choose to use this study to compare the pre-operative exercise group against the control group, the subgroup scores never reached the MDC. Based on this, there isn't a difference between the two groups.

My second issue has to do with 

the cost aspect. I tend to get confused with Quality of Adjusted Life Years. Paying $42,000 USD for QALY is outside of $24,760 - 37,140 USD.  If there is an actual target of cost for QALY, then that needs to be the target goal in order to curb costs.

Here's a quick view of the abstract. 

Supervised neuromuscular exercise prior to hip and knee replacement: 12-month clinical effect and cost-utility analysis alongside a randomised controlled trial.




There are indications of beneficial short-term effect of pre-operative exercise in reducing pain and improving activity of daily living after total hip replacement (THR) and total knee replacement (TKR) surgery. Though, information from studies conducting longer follow-ups and economic evaluations of exercise prior to THR and TKR is needed. The aim of the study was to analyse 12-month clinical effect and cost-utility of supervised neuromuscular exercise prior to THR and TKR surgery.


The study was conducted alongside a randomised controlled trial including 165 patients scheduled for standard THR or TKR at a hospital located in a rural area of Denmark. The patients were randomised to replacement surgery with or without an 8-week preoperative supervised neuromuscular exercise program (Clinical Trials registration no.: NCT01003756). Clinical effect was measured with Hip disability and Osteoarthritis Outcome Score (HOOS) and Knee injury and Osteoarthritis Outcome Score (KOOS). Quality adjusted life years (QALYs) were based on EQ-5D-3L and Danish preference weights. Resource use was extracted from national registries and valued using standard tariffs (2012-EUR). Incremental net benefit was analysed to estimate the probability for the intervention being cost effective for a range of threshold values. A health care sector perspective was applied.


HOOS/KOOS quality of life [8.25 (95% CI, 0.42 to 16.10)] and QALYs [0.04 (95% CI, 0.01 to 0.07)] were statistically significantly improved. Effect-sizes ranged between 0.09-0.59 for HOOS/KOOS subscales. Despite including an intervention cost of €326 per patient, there was no difference in total cost between groups [€132 (95% CI -3942 to 3679)]. At a threshold of €40,000, preoperative exercise was found to be cost effective at 84% probability.


Preoperative supervised neuromuscular exercise for 8 weeks was found to be cost-effective in patients scheduled for THR and TKR surgery at conventional thresholds for willingness to pay. One-year clinical effects were small to moderate and favoured the intervention group, but only statistically significant for quality of life measures.

BMC Musculoskelet Disord. 2017 Jan 6;18(1):5. doi: 10.1186/s12891-016-1369-0.