The augmented rehabilitation program was feasible, acceptable and safe in patients ≤ 60 years undergoing elective unilateral THA. Recruitment of target population (patients ≤ 60 years undergoing elective unilateral THA) from Edmonton Hip and Knee Clinic was successful. The baseline and follow-up assessments were also implemented and accepted by all the study participants. When compared to the control group, improvements were seen with the augmented rehabilitation program in step count, MVPA bouts of activity, HOOS symptoms and pain subscales. This feasibility study will inform the design of a future randomized controlled trial to examine the effectiveness of augmented rehabilitation program in patients ≤ 60 years undergoing elective unilateral THA.
Other studies that have examined step count in younger patients recovering from THA reported less daily steps at 6 months after surgery (55). In comparison to our intervention group, Fujita et al., reported lower step counts (5,657 steps), light activity (107 min/day) and MVPA (17 min/day) at 6 months after THA.) (56). The differences in step counts and MVPA bouts could be due to the diversity in methods of measuring objective physical activity, such as pedometers (56), mobile step-tracking application (55) or accelerometer. A systematic review and meta-analysis examined the changes in PA after total joint replacement and included 7 studies (336 participants) (57). This review showed that there was no significant increase in PA at 6 months when compared to baseline (SMD 0.1, 95% CI = 0.1, 0.3) and large improvements in self-reported physical function (SMD 0.9, 95% CI 0.1, 1.8) (57). The lack of increased PA that was shown in our results and Hammett et al (57) could be behavioral in nature, as a sedentary lifestyle is difficult to change. Future studies that focus on changing sedentary behavior are needed.
The Canadian physical activity guidelines for adults aged 18–64 years include at least 150 minutes of MVPA per week to achieve health benefits(58). The average time patients in the intervention group spent on MVPA daily was approximately 176.2 min/week and they met the guideline determined by the Canadian Society for Exercise Physiology (CSEP)(58). Compared to the control group, the intervention group has more MVPA bouts per week (21.0 versus 11.3) at the follow-up assessment than the control group. After accounting for baseline differences, there was a statistically significant differences of MVPA bouts between groups. These between-group differences appear to be clinically important and show the potential effectiveness of the intervention.
The positive effects of the augmented rehabilitation we found may be attributed to a few features of the program such as structured classes led by physiotherapists, high intensity activities, and available equipment. A systematic review found that the center-based exercise rehabilitation is more effective than the home-based exercise for THA patients’ recovery (59) because of the higher training intensity and access to professional supervision, specialised equipment and facilities in center-based exercise (59). Hydrotherapy with OA has positive effects to reduce pain (SMD = − .4; 95% CI = -0.6 to -0.2) and to improve physical function (SMD = 0.3, 95% CI = 0.1–0.5) for adults with musculoskeletal conditions (60). Exercise in water offloads weight bearing and may allow people with hip pain, swelling, leg weakness to exercise successfully when this may not be possible on land (61–63). Thirdly, as the PA guidelines recommended, it is beneficial to add muscle and bone strengthening activities to the exercise regimen for people aged 60 years or younger (64).
Primary clinical goals of joint replacement surgery are pain relief, and functional improvement. We noted there was significant pain relief reported by only the intervention group. More recently, physical activity has become another outcome. Others have shown weak to moderate correlation between PA using an accelerometer and self-reported PA questionnaires in people with hip OA and Post-THA (65). We found similar findings in that the correlation between the bouts of MVPA and step count did not correlate with self-reported pain, and function, yet moderate correlations were seen with the HOOS QoL and step counts and MVPA bouts (52). This correlation confirms the results of previous population-based studies that showed association of health-related quality of life and physical activities (66, 67).
In recent years, the length of hospital stay post-THA has been reduced to 3–4 days which can be attributable to advances in surgical and prosthetic technologies. The ramification of an earlier hospital discharge is that the recovery time with a specialized care team and active rehabilitation has been limited (68). At discharge, patients receive a guide for continuing strengthening, stretching, and ambulation exercises; however, they are expected to complete this exercise program independently. In a prospective study, it was reported that many patients would have liked to spend more time with their physiotherapists which could be due to insecurities or lack of confidence of the patient in performing activities alone (68, 69). The proposed post-operative rehabilitation program provides additional contact and supervised exercise time with physiotherapists, which may be necessary beyond the limited length of stay, to enable patients to return to full activity.
By tailoring and implementing an augmented THA rehabilitation program to younger patients (≤ 60 years), precision medicine approach may be used to tailor pre- or post-operative rehabilitation intervention to prevent potential deleterious outcomes for this population. There is a growing need to transform our healthcare delivery system from a reactive approach to a more personalized system of predictive, preventive, and precision healthcare by integrating evidence-based medicine and precision diagnostics into clinical practice (70). After implementation of a tailored post-operative rehabilitation programs for patients at risk, this research program has the potential of preventing post-operative independence and complication which lead to healthcare cost saving.
Our findings should be considered within context of this feasibility study design in that the program was acceptable as reflected by attendance; retention no adverse event, and no complication reported. This study addresses the understudied area of post-THA rehabilitation of patients 60 years or younger. A strength of this study was including subjective (HOOS) objective measure of PA as well as examining the correlation between these two measures. We showed the feasibility of implementing an augmented rehabilitation program (including land and water-based exercise) in THA patients who are 60 years or younger and support a definitive trial.
Although this study had insufficient power to detect change with some outcomes, the reported change will be valuable in sample size calculations for larger trials. Long-term sustainability of the program is unknown, and recommendations for a 6 month follow-up may be warranted given that other post-operative rehabilitation program for THA have reported sustained change for 6 months (55). Although the control group were age and sex matched, a randomized control trial is recommended to identify any congruent findings.