Safe Activity participation Following Elective Total hip replacement: the SAFE-T investigation.

Objectives: Total hip replacement (THR) is one of the most common elective orthopaedic surgeries performed, with increasing demand among younger individuals. Few evidence-based guidelines exist on safe activity participation following THR, including whether high-intensity sport participation is safe for individuals. The purpose of this study was to identify if increased intensity of physical activity following THR was associated with increased activity-related pain and increased revision rates.

Methods: Two groups undergoing THR were recruited: preoperative (cohort 1) and 5-7 years postsurgery (cohort 2); both followed for 5 years. Activity was self-reported through validated questionnaires and grouped into categories from 'A' (low intensity, eg, aquafit) to 'F' (high intensity, eg, tennis). The primary outcome was the presence of hip pain during activity (binary variable, Y/N), measured by the association between hip pain and intensity of activity (categories A-F). Secondary outcomes included activity duration, revision rate or a change in patient-reported outcome measures (PROMs).

Results: 1098 individuals were included in this study (cohort 1: n=588, cohort 2: n=510). Regression analysis showed no significant interaction between activity intensity and hip pain across all time points. Approximately 20.6% of all activity (11.0% of participants) occurred in the highest intensity categories (E and F); these subjects showed no decrease in activity duration, worsening PROMs or increased revision rates compared with lower intensity activity groups (all p>0.05). When analysing by individual activities, certain activities (eg, snowboarding, squash, tennis and backpacking) were more correlated with hip pain (r>0.60), while others (eg, snorkelling, swimming, home weights, aquafit, cross-country skiing and sledding) were less likely to have hip pain (r<-0.60).

Conclusions: This study showed that higher-intensity activities do not lead to decreased activity duration, worsening patient-reported outcomes or increased revision rates following THR, although certain activities may be associated with increased pain. These findings can inform patient counselling after THR.