Is running good or bad for your knees? A systematic review and meta-analysis of cartilage morphology and composition changes in the tibiofemoral and patellofemoral joints

Abstract

The general health benefits of running are well-established, yet concern exists regarding the development and progression of osteoarthritis. To systematically review the immediate (within 20min) and delayed (20min-48h) effect of running on hip and knee cartilage, as assessed using magnetic resonance imaging (MRI). Studies using MRI to measure change in hip or knee cartilage within 48h pre- and post-running were identified. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Percentage change in cartilage outcomes were estimated using random-effects meta-analysis. Certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation tool. Twenty-four studies were included, evaluating 446 knees only. One third of studies were low risk of bias. Knee cartilage thickness and volume decreased immediately after running, with declines ranging from 3.3% (95% confidence interval [CI]: 2.6%, 4.1%) for weight-bearing femoral cartilage volume to 4.9% (95% CI: 4.43.6%, 6.2%) for patellar cartilage volume. T1ρ and T2 relaxation times were also reduced immediately after running, with the largest decline being 13.1% (95% CI:-14.4%,-11.7%) in femoral trochlear cartilage. Tibiofemoral cartilage T2 relaxation times recovered to baseline levels within 91min. Existing cartilage defects were unchanged within 48h post-run. There is very low certainty evidence that running immediately decreases the thickness, volume, and relaxation times of patellofemoral and tibiofemoral cartilage. Hip cartilage changes are unknown, but knee changes are small and appear transient suggesting that a single bout of running is not detrimental to knee cartilage.