The review found that progressive resistance training improved muscle strength and function after total hip replacement, regardless of the timing of the intervention. Due to limitations in the review, including failure to systematically assess study quality and variation between the studies, these findings may not be reliable.

To evaluate the effectiveness of rehabilitation interventions to improve functional outcomes after total hip replacement.

MEDLINE (from 1950), EMBASE (from 1980) and CINAHL were searched for studies published in English. Search terms were reported. Final search dates were not reported.

Eligible studies were randomised controlled trials (RCTs) of postoperative exercise rehabilitation interventions to improve functional outcomes after total hip arthroplasty for osteoarthritis. End points of interest in the review included functional outcomes and dislocation rates.

Several studies in the review had mixed populations: they included not only participants who had had hip arthroplasty but also some who had had knee arthroplasty. Interventions were defined as early or late (more or less than a month post surgery). The most commonly used type of rehabilitation was progressive resistance training. There was a wide variety of specific interventions (such as hydrotherapy, treadmill, electrical stimulation and ergometer cycling), control conditions (such as standard in-patient physiotherapy, passive physiotherapy and no exercise), and outcomes (such as walking tests, functional questionnaires and pain scores). The interval between surgery and the intervention ranged from the immediate postoperative period to at least 1.5 years afterwards. The duration and intensity of the intervention varied, and the duration of follow-up ranged from six days to two years.

The authors did not state how many reviewers performed study selection.

No criteria for quality assessment were described and it did not appear that study quality was systematically assessed, but the reviewers reported some specific limitations of individual studies.

Descriptive data of outcomes in each study were extracted and were presented in a table. The authors did not state how many reviewers performed the data extraction. Primary study authors were contacted for more information if required.

Studies were combined in a narrative synthesis. Findings were described with a vote-counting approach, which reported what proportion of the studies found a significant benefit from the intervention, with equal weight given to each study.

Fifteen RCTs were included (1,065 participants, range 23 to 234). Limitations mentioned in the review included lack of allocation concealment (one RCT), drop-out rates of 33% to 38% (two RCTs) and short follow-up (most studies).

All centre-based studies that utilised progressive resistance training (six RCTs) showed that the intervention significantly improved functional outcomes. Two home-based studies that used resistance training in the late postoperative phase also reported significant benefits. Only one out of five centre-based studies and neither of two home/centre-based studies that used interventions other than progressive resistance training reported a significant benefit from the intervention. No significant difference in outcomes was found between home and centre based settings (two RCTs). Exercise interventions did not appear to have increased the risk of dislocation.

Progressive resistance training improves muscle strength and function after total hip replacement, regardless of the timing of the intervention.

The broad objectives of the review were clear but the comparisons of interest were not clearly defined. The search was limited to published studies in English, which meant that some studies may have been missed. The risk of publication bias was not discussed. The final search date was not reported. It was unclear whether study selection and data extraction were undertaken with sufficient attempts to minimise reviewer error and bias and it did not appear that study quality was systematically assessed.

The studies differed widely in their interventions, comparisons and outcomes, and some studies included participants who had not had hip surgery. It was unclear whether reported findings related to between-group comparisons or to changes from baseline, measures of significance (such as p values) were not reported for all comparisons, and measures of statistical variability were not reported. The authors’ conclusions regarding progressive resistance training were potentially confounded by other differences between the studies. As the authors noted, the review was limited by lack of studies with long-term follow-up. Due to limitations in the review, including failure to systematically assess study quality and heterogeneity between the studies, the authors’ findings may not be reliable.

Practice: The authors stated that after total hip replacement patients benefit from early progressive resistance training conducted in a rehabilitation centre, though they noted that transport and supervision costs were disadvantages of this approach.

Research: The authors stated that there was a need for studies of early progressive resistance training administered at home, with long-term follow-up.

The Betsi Cadwaladr University Health Board Small Grants Committee.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.