This summary of a Cochrane review presents what we know from research about the effect of joint lavage for osteoarthritis (OA) of the knee. The review shows that in people with OA, joint lavage;
- may not improve pain and function compared to a sham treatment or no treatment.
We often do not have precise information about side effects and complications. This is particularly true for rare but serious side effects.
What is osteoarthritis and what is joint lavage
Osteoarthritis (OA) is the most common form of arthritis that can affect the hands, hips, and knees. In OA, the cartilage breaks down and may cause swelling and consecutive pain. OA can occur in different areas of the knee or the whole knee. When the cartilage breaks down, bits of tissue are left around the knee joint, which can add to the inflammation and prevent the joint from working properly.
Joint lavage means to wash out any loose tissue or debris from inside the joint space. It involves temporally inserting small tubes into 1 or more entry points into the knee.
This systematic review discusses three types of joint lavage. Tidal irrigation joint lavage uses only one entry point to alternately inject fluid, and then draw it out. Non-arthroscopic joint lavage uses two entry points, one to inject the fluid and a separate one for the withdrawal of the fluid, but no visual inspection of the knee is performed. Arthroscopic joint lavage is a formal joint lavage in addition to a visually inspection of the knee joints structures as this is done.
Joint lavage does not result in a relevant benefit for patients with knee osteoarthritis in terms of pain relief or improvement of function.
Osteoarthritis is the most common form of joint disorder and a leading cause of pain and physical disability. Observational studies suggested a benefit for joint lavage, but recent, sham-controlled trials yielded conflicting results, suggesting joint lavage not to be effective.
To compare joint lavage with sham intervention, placebo or non-intervention control in terms of effects on pain, function and safety outcomes in patients with knee osteoarthritis.
We searched CENTRAL, MEDLINE, EMBASE, and CINAHL up to 3 August 2009, checked conference proceedings, reference lists, and contacted authors.
We included studies if they were randomised or quasi-randomised trials that compared arthroscopic and non-arthroscopic joint lavage with a control intervention in patients with osteoarthritis of the knee. We did not apply any language restrictions.
Two independent review authors extracted data using standardised forms. We contacted investigators to obtain missing outcome information. We calculated standardised mean differences (SMDs) for pain and function, and risk ratios for safety outcomes. We combined trials using inverse-variance random-effects meta-analysis.
We included seven trials with 567 patients. Three trials examined arthroscopic joint lavage, two non-arthroscopic joint lavage and two tidal irrigation. The methodological quality and the quality of reporting was poor and we identified a moderate to large degree of heterogeneity among the trials (I2 = 65%). We found little evidence for a benefit of joint lavage in terms of pain relief at three months (SMD -0.11, 95% CI -0.42 to 0.21), corresponding to a difference in pain scores between joint lavage and control of 0.3 cm on a 10-cm visual analogue scale (VAS). Results for improvement in function at three months were similar (SMD -0.10, 95% CI -0.30 to 0.11), corresponding to a difference in function scores between joint lavage and control of 0.2 cm on a WOMAC disability sub-scale from 0 to 10. For pain, estimates of effect sizes varied to some degree depending on the type of lavage, but this variation was likely to be explained by differences in the credibility of control interventions: trials using sham interventions to closely mimic the process of joint lavage showed a null-effect. Reporting on adverse events and drop out rates was unsatisfactory, and we were unable to draw conclusions for these secondary outcomes.