The benefits of adding manual therapy to exercise therapy for improving pain and function in patients with knee or hip osteoarthritis - a systematic review with meta-analysis

Objective
To evaluate if there was an additional benefit of combining manual therapy (MT) and exercise therapy over exercise therapy alone on pain and function in patients with hip or knee osteoarthritis

Design
Intervention systematic review

Literature search
We (i) searched 4 databases from inception to 20 June, 2021, (ii) hand searched reference list of included trials and relevant systematic reviews and (iii) contacted two researchers in the field.

Study selection criteria
We included randomized controlled trials that compared MT plus exercise therapy to similar exercise therapy programs alone in patients with hip or knee osteoarthritis.

Data synthesis
The data were combined using random-effects meta-analyses where appropriate. The certainty of evidence for each outcome was judged using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

Results
We included 19 trials. There was very low to moderate certainty evidence that MT added benefit in the short-term for pain, and combined pain, function and stiffness (WOMAC global scale), but not for performance-based function and self-reported function. In the medium-term, there was low to very low certainty evidence that MT added benefit for performance-based function and WOMAC global score, but not for pain. There was high certainty evidence that MT provided no added benefit in the long-term for pain and function.

Conclusion
There was very low to moderate certainty evidence supporting MT as an adjunct to exercise therapy for pain and WOMAC global scale but not function in patients with knee or hip osteoarthritis in the short-term. There was high certainty evidence of no benefit for additional MT over exercise therapy alone in the long-term.