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

Key points

1. 01Manual therapy here means any clinician-delivered hands-on technique (joint mobilization, manipulation, soft tissue work, or stretching) layered on top of exercise.
2. 02Short-term pain showed a large pooled benefit (SMD -0.82), but excluding high risk-of-bias trials dropped it to a small, nonsignificant effect (SMD -0.33).
3. 03The combined WOMAC global score (pain, function, stiffness) favored manual therapy in the short term with moderate certainty (SMD -1.05).
4. 04By the long term, high-certainty evidence showed no added benefit for pain, WOMAC, or the Timed Up and Go test.
5. 05Self-reported and performance-based function showed no clear short-term benefit, so improvements were not consistent across outcomes.

How it was conducted

Design

Systematic review with random-effects meta-analysis, GRADE certainty, PROSPERO registered

Search

PubMed, PEDro, CINAHL, Cochrane Library from inception to June 2021, plus hand searching and expert contact; 19 RCTs included (17 in quantitative synthesis)

Participants

1394 adults with knee (n=1147) or hip (n=247) osteoarthritis across 18 trials

Intervention

Manual therapy plus exercise therapy versus the same exercise therapy alone

Outcomes

Pain, self-reported function, performance-based function (Timed Up and Go), and WOMAC global scale at short, medium, and long term

Analysis

DerSimonian and Laird random-effects pooling of MD or SMD, with sensitivity analyses excluding 9 high risk-of-bias trials

What they found

• Short-term pain: large benefit of added manual therapy (SMD -0.82, 95% CI -1.22 to -0.43, I2=85%, very low certainty).
• Short-term pain after excluding high risk-of-bias trials (5 trials remained): SMD -0.33 (95% CI -0.76 to 0.03), no longer statistically significant.
• Short-term WOMAC global scale: large benefit (SMD -1.05, 95% CI -1.52 to -0.59, I2=87%, moderate certainty); dropped to medium (SMD -0.61) after excluding high risk-of-bias trials.
• Long-term pain: no benefit (MD on NRS 0-10 -0.14, 95% CI -0.48 to 0.21, I2=66%, high certainty).
• Long-term WOMAC global and Timed Up and Go: no added benefit with high certainty.
• Short-term self-reported function: no benefit (SMD -0.27, 95% CI -0.85 to 0.30, low certainty).

Limitations

• Nine of 19 trials were at high risk of bias, and these drove the short-term pain benefit.
• Treatment time was balanced between groups in only 4 trials, so extra attention and nonspecific effects could explain some short-term gains.
• Manual therapy techniques, frequency, and dose varied widely, so no conclusions could be drawn about which type or dose is best.
• Only 2 trials studied hip osteoarthritis alone, limiting hip-specific conclusions.

Why it matters

For patients

Hands-on therapy added to your exercise program may help a little with pain in the first few weeks, but it does not give lasting benefit over exercise alone.

For clinicians

Prioritize exercise and education, then consider manual therapy as an optional short-term adjunct if time allows, while being clear there is no long-term benefit.

For readers

Manual therapy adds, at best, a fragile short-term edge over exercise for osteoarthritis and no long-term benefit.