Approved Research

The associations between levels of physical activity, handgrip strength and cardio-respiratory fitness with the risk of total hip or knee replacement within 7 years, a study of the UK Biobank cohort.

Lay summary

Aim: Our aim is to investigate the associations between levels of physical activity, handgrip strength and cardio-respiratory fitness with the risk of total joint replacement (TJR) of the hip or knee within 7 years.

Scientific rationale: Existing evidence on the relationship between physical activity and TJR is inconclusive. The literature includes findings that physical activity is associated with a protective effect, no association or an increased risk of TJR. One reason for these contradictions may be that in most existing studies physical activity levels were self-reported by participants, which is susceptible for report bias. There has been a limited number of studies in which physical activity was measured objectively. Another reason may be the differences in population characteristics between studies. A recent systematic review recommended future research to investigate biomarkers to determine who is likely to experience a more favourable response to physical activity as opposed to who has an increased risk of total joint replacement. The large sample size of the UK Biobank, objective measurements of physical activity and the availability of other exercise related measurements, provide a novel opportunity to better understand the associations of physical activity and fitness, with the risk of TJR.

Project duration: The project is estimated to not take longer than 2 years.

Public health impact: The TJR burden is high and steadily increasing around the world. If the current trend in surgical management of osteoarthritis continues, it can become financially unsustainable. Exercise is internationally recommended as cornerstone treatment for osteoarthritis. However, in clinical practice, there is a high use of pharmacological and surgical treatments, sometimes without trying exercise first. There is a lack of confidence in the benefits and safety of physical activity among general practitioners and their patients. A better understanding of the levels of physical activity and fitness that are safe and beneficial for individuals with osteoarthritis can provide guidance to stakeholders and may stimulate adherence to physical activity guidelines.