Exercise as Medicine During the Course of Hip Osteoarthritis

Inger Mechlenburg; Lisa Cecilie Urup Reimer; Troels Kjeldsen; Thomas Frydendal; Ulrik Dalgas


Exerc Sport Sci Rev. 2021;49(2):77-87. 

In This Article

Exercise as Secondary and Tertiary Prevention in Severe Hip OA

Severe hip OA is associated with high levels of joint pain, decreased muscle strength, marked functional limitations, and reduced QoL.[30,83–88] Eventually, THA may be scheduled, and in patients awaiting THA, pain and patient-reported function have been reported to deteriorate further within 3 to 6 months.[86,89]

Exercise has primarily been investigated in patients scheduled for THA aiming to determine either the immediate or the postoperative effect.[48–52,62,64,90,91] Two meta-analyses have investigated the immediate effects of preoperative exercise on patient-reported function and pain in patients with severe hip OA awaiting THA.[48,51] Both found low- to moderate-quality evidence for a medium effect of preoperative exercise (aerobic, strengthening, neuromuscular, stretching, and mixed) for improving physical function and reducing pain, when compared with standard care or no intervention.[48,51] In line, two recent high-quality RCTs not included in the meta-analyses reported a medium-size effect for improvement of patient-reported physical function and pain levels, when comparing supervised preoperative exercise with standard care.[49,90] However, one meta-analysis focused specifically on walking ability and reported no beneficial effect of exercise compared with standard care.[48] In contrast, a recent high-quality RCT showed that supervised neuromuscular exercise improved performance-based function (i.e., chair rise and walking speed) compared with standard preoperative care.[90] Muscle strength has also been investigated in several studies, and a meta-analysis identified three studies that assessed muscle strength and showed no significant differences between preoperative exercise and standard care in patients with severe hip OA before THA.[48] Similarly, a recent RCT evaluating neuromuscular exercise did not improve leg muscle power measured during single-joint hip abduction or extension and multijoint leg extension more than standard preoperative care.[90] Contrasting these previous findings, a more recent RCT showed that progressive resistance training provided clinically relevant improvements in multijoint leg extension power compared with standard preoperative care,[49] suggesting that training modality, volume, or a too low exercise intensity may explain the lack of improvement in previous studies. Finally, three RCTs measured the immediate exercise effect on patient-reported QoL, of which one study reported no difference,[90] whereas two studies found small improvements compared with standard preoperative care.[49,63] Currently, only sparse evidence exists evaluating whether exercise may be a viable treatment option for postponing or even replacing THA in some patients with severe hip OA. Interestingly, Pisters et al.[92] reported that after 12 wk of exercise ("behavioral graded exercise") followed by booster sessions, only 6 (20%) patients with hip OA underwent THA during the study period compared with 18 (45%) patients with hip OA in the usual care group. Given the importance of this question, it is encouraging that this knowledge gap is being further investigated in two ongoing RCTs.[93,94]

Three meta-analyses have investigated the postoperative effects of preoperative exercise on pain and physical function in patients with severe hip OA undergoing THA.[51,52,62] One of the meta-analyses reported no beneficial effect of preoperative exercise on patient-reported and performance-based function compared with standard care, when evaluated within 3 months after THA.[62] This result was partly supported by another meta-analysis, reporting low-quality evidence for no additional effect of preoperative exercise on short-term postoperative patient-reported function, but moderate quality evidence for short-term benefits on surgeon-reported function (the Harris Hip score).[51] Furthermore, a recent meta-analysis found a small to moderate effect favoring preoperative exercise for improving postoperative patient-reported pain and function compared with standard care.[52] A recent high-quality RCT not included in any of the meta-analyses investigated both the short- and long-term postoperative effects of preoperative progressive resistance training on patient-reported pain, function, and QoL and performance-based function, reporting short-term improvements in both patient-reported and performance-based function (i.e., chair rise, walking speed, and ascending stairs). However, at the 12-month follow-up, there were almost no additional postoperative effects in favor of preoperative progressive resistance training.[64] Finally, muscle strength has been evaluated in a recent meta-analysis reporting no short-term effect of preoperative exercise on postoperative quadriceps muscle strength compared with standard care. However, none of the included studies measured hip muscle strength despite the obvious relevance.[52] Two recent high-quality RCTs not included in the meta-analysis measured the effects of preoperative exercise on postoperative muscle strength or power.[50,64] Neuromuscular exercise showed improved single-joint hip extension muscle power of the unaffected leg 3 months postoperatively,[50] whereas preoperative progressive resistance training demonstrated improved short-term postoperative muscle strength for knee extension of the affected and unaffected leg compared with standard care.[64] In summary, preoperative exercise may offer tertiary prevention in terms of improved levels of patient-reported pain and function and muscle strength in patients with severe hip OA when assessed before or shortly after THA, whereas the effects seem to cease at longer follow-up. No evidence supporting secondary preventive effects of exercise could be located.