This review concluded that lateral-wedge insoles with subtalar strapping significantly decreased short-term pain and appeared to have a positive effect on femoral-tibial angle in the long-term, compared to conventional insoles without strapping. This conclusion should be viewed with caution, as the review included only three small, poor quality studies and most effects were non-significant.

To assess the effectiveness of lateral-wedged insoles, with subtalar strapping, in reducing pain and improving function and femoral-tibial angle in adults with medial knee osteoarthritis, compared with conventional insoles without subtalar strapping.

PubMed, The Cochrane Library, CINAHL, Science Direct, PEDro and BioMed Central were searched to March 2009 and search terms were reported. Only studies in English were included.

Eligible randomised controlled trials (RCTs) compared lateral-wedged insoles with subtalar strapping and an incline of five to 12 degrees to insoles without strapping, in adults (18 years or older) with radiographically confirmed medial knee osteoarthritis. Outcomes of interest were pain (visual analogue scale or similar), function (Lequesne index, 50 feet walk time, five chair stand time or similar) and femoral-tibial angle (measured radiographically).

Participants were excluded if they: used any type of wedged insole or walking aid pre-trial; had limited ability to wear shoes; had neuropathies; had symptomatic co-morbidities affecting walking more than the knee osteoarthritis; were unwilling to start new medication during the trial; had knee hip or ankle surgery; had peripheral or central nervous systema diseases; had hip lumbar spine and ankle osteoarthritis; had secondary knee osteoarthritis or symptomatic deformity of the foot and ankle; had any other disease treated with insoles; or had received intra-articular injections in the previous six months.

Non-steroidal anti-inflammatory drugs or analgesics during trials were permitted.

All included studies were conducted in orthopaedic clinics in Japan, between 2001 and 2006. The mean age of study participants ranged from 60 to 67 years and all participants were female.

Two reviewers independently assessed studies for inclusion and any disagreements were resolved in consultation with a third reviewer.

The methodological quality of included studies was assessed with the 11-item PEDro scale, which assessed randomisation, allocation concealment, baseline similarity, blinding of patients, clinicians and assessors, reporting of outcomes, withdrawals and use of intension-to-treat analysis. An overall quality score (maximum 11) was calculated for each study.

The methodological quality of included studies was independently assessed by two reviewers and any disagreements were resolved in consultation with a third reviewer.

Data were extracted to calculate the mean difference, with 95% confidence intervals (CIs) between treatment and control groups, for each outcome measure reported.

Data were independently extracted by two reviewers and study authors were contacted for any missing information.

Pooled estimates of mean difference, with 95% confidence intervals, were calculated with a fixed-effect model. No study weighting was specified.

Between-study heterogeneity was assessed qualitatively, based on consideration of similarity of populations, condition, interventions and outcomes and statistically using Χ² and Ι².

Three RCTs with a total of 212 participants were included in the review. Two studies had a quality score of five and one had a quality score of seven. No study reported allocation concealment, blinding of participant or therapists or use of intension-to-treat analysis.

Lateral-wedge insoles with subtalar strapping were associated with reduced pain over the short-term, compared to the control group (mean difference -10.25, 95% CI, -17.17 to -3.32; two studies) There was no significant between-study heterogeneity. Individual studies found no significant difference between treatment and control groups when short, medium and long term pain were assessed separately.

No significant differences in femoral-tibial angle, between treatment and control groups, were found at any time point, but the authors reported a trend towards better outcomes in the treatment group over the medium to long term.

Lateral-wedge insoles with subtalar strapping significantly decreased short-term pain and appeared to have a positive effect on femoral-tibial angle in the long-term, compared with conventional insoles without strapping.

The review reported a clear research objective and fully defined inclusion criteria. Several sources were searched for relevant studies, but the restriction to studies in English raised the possibility of language bias and omission of relevant studies. Measures to minimise error and/or bias were taken throughout the review process and the methodological quality of included studies was assessed and reported in full. Given that only three small, poor quality studies were included and effects were non-significant in most cases, the authors' conclusions should be viewed with caution.

Practice: The authors stated that lateral-wedge insoles with subtalar strapping may provide a financially feasible add-on self-management treatment for knee osteoarthritis, and should be considered before invasive procedures such as surgery.

Research: The authors did not specify any recommendations for future research.

Not stated.

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.