Background Individuals with osteoarthritis (OA) of the knee can be treated with a knee brace or a foot/ankle orthosis. The main purpose of these aids is to reduce pain, improve physical function and, possibly, slow disease progression. This is the second update of the original review published in Issue 1, 2005, and first updated in 2007. Objectives To assess the benefits and harms of braces and foot/ankle orthoses in the treatment of patients with OA of the knee. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE (current contents, HealthSTAR) up to March 2014. We screened reference lists of identified trials and clinical trial registers for ongoing studies. Selection criteria Randomised and controlled clinical trials investigating all types of braces and foot/ankle orthoses for OA of the knee compared with an active control or no treatment. Data collection and analysis Two review authors independently selected trials and extracted data. We assessed risk of bias using the ' Risk of bias' tool of The Cochrane Collaboration. We analysed the quality of the results by performing an overall grading of evidence by outcome using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. As a result of heterogeneity of studies, pooling of outcome data was possible for only three insole studies. Main results We included 13 studies (n = 1356): four studies in the first version, three studies in the first update and six additional studies (n = 529 participants) in the second update. We included studies that reported results when study participants with early to severe knee OA (Kellgren & Lawrence grade I-IV) were treated with a knee brace (valgus knee brace, neutral brace or neoprene sleeve) or an orthosis (laterally or medially wedged insole, neutral insole, variable or constant stiffness shoe) or were given no treatment. The main comparisons included (1) brace versus no treatment; (2) foot/ankle orthosis versus no treatment or other treatment; and (3) brace versus footankle orthosis. Seven studies had low risk, two studies had high risk and four studies had unclear risk of selection bias. Five studies had low risk, three studies had high risk and five studies had unclear risk of detection bias. Ten studies had high risk and three studies had low risk of performance bias. Nine studies had low risk and four studies had high risk of reporting bias. Four studies compared brace versus no treatment, but only one provided useful data for metaanalysis at 12month followup. One study (n = 117, lowquality evidence) showed lack of evidence of an effect on visual analogue scale (VAS) pain scores (absolute percent change 0%, mean difference (MD) 0.0, 95% confidence interval (CI) 0.84 to 0.84), function scores (absolute percent change 1%, MD 1.0, 95% CI 2.98 to 4.98) and healthrelated quality of life scores (absolute percent change 4%, MD 0.04, 95% CI 0.12 to 0.04) after 12 months. Many participants stopped their initial treatment because of lack of effect (24 of 60 participants in the brace group and 14 of 57 participants in the no treatment group; absolute percent change 15%, risk ratio (RR) 1.63, 95% CI 0.94 to 2.82). The other studies reported some improvement in pain, function and healthrelated quality of life (P value <= 0.001). Stiffness and treatment failure (need for surgery) were not reported in the included studies. For the comparison of laterally wedged insole versus no insole, one study (n = 40, lowquality evidence) showed a lower VAS pain score in the laterally wedged insole group (absolute percent change 16%, MD 1.60, 95% CI 2.31 to 0.89) after nine months. Function, stiffness, healthrelated quality of life, treatment failure and adverse events were not reported in the included study. For the comparison of laterally wedged versus neutral insole after pooling of three studies (n = 358, moderatequality evidence), little evidence was found of an effect on numerical rating scale (NRS) pain scores (absolute percent change 1.0%, MD 0.1, 95% CI 0.45 to 0.65), Western OntarioMcMaster Osteoarthritis Scale (WOMAC) stiffness scores (absolute percent change 0.1%, MD 0.07, 95% CI 4.96 to 5.1) and WOMAC function scores (absolute percent change 0.9%, MD 0.94, 95% CI 2.98 to 4.87) after 12 months. Evidence of an effect on healthrelated quality of life scores (absolute percent change 1.0%, MD 0.01, 95% CI 0.05 to 0.03) was lacking in one study (n = 179, moderatequality evidence). Treatment failure and adverse events were not studied for this comparison in the included studies. Data for the comparison of laterally wedged insole versus valgus knee brace could not be pooled. After six months' followup, no statistically significant difference was noted in VAS pain scores (absolute percent change 2.0%, MD 0.2, 95% CI 1.15 to 0.75) and WOMAC function scores (absolute percent change 0.1%, MD 0.1, 95% CI 7.26 to 0.75) in one study (n = 91, lowquality evidence); however both groups showed improvement. Stiffness, healthrelated quality of life, treatment failure and adverse events were not reported in the included studies for this comparison. Authors' conclusions Evidence was inconclusive for the benefits of bracing for pain, stiffness, function and quality of life in the treatment of patients with medial compartment knee OA. On the basis of one laterally wedged insole versus no treatment study, we conclude that evidence of an effect on pain in patients with varus knee OA is lacking. Moderatequality evidence shows lack of an effect on improvement in pain, stiffness and function between patients treated with a laterally wedged insole and those treated with a neutral insole. Lowquality evidence shows lack of an effect on improvement in pain, stiffness and function between patients treated with a valgus knee brace and those treated with a laterally wedged insole. The optimal choice for an orthosis remains unclear, and longterm implications are lacking.