Abstract: Ten randomised controlled trials were included. Limitations in the design, conduct and reporting of these trials resulted in unclear or high risk of bias assessments relating to allocation concealment, assessor blinding, incomplete and selective outcome reporting. Only limited pooling of the data was possible. Neuromuscular training was the basis of conservative treatment evaluated in four trials. Neuromuscular training compared with no training resulted in better ankle function scores at the end of four weeks training (Ankle Joint Functional Assessment Tool (AJFAT): mean difference (MD) 3.00, 95% CI 0.3 to 5.70; 1 trial, 19 participants; Foot and Ankle Disability Index (FADI) data: MD 8.83, 95% CI 4.46 to 13.20; 2 trials, 56 participants). The fourth trial (19 participants) found no significant difference in the functional outcome after six weeks training programme on a cyclo-ergometer with a bi-directional compared with a traditional uni-directional pedal. Longer-term follow-up data were not available for these four trials. Four studies compared surgical procedures for chronic ankle instability. One trial (40 participants) found more nerve injuries after tenodesis than anatomical reconstruction (risk ratio (RR) 5.50, 95% CI 1.39 to 21.71). One trial (99 participants) comparing dynamic versus static tenodesis excluded 17 patients allocated dynamic tenodesis because their tendons were too thin. The same trial found that dynamic tenodesis resulted in higher numbers of people with unsatisfactory function (RR 8.62, 95% CI 1.97 to 37.77, 82 participants). One trial comparing techniques of lateral ankle ligament reconstruction (60 participants) found that operating time was shorter using the reinsertion technique than the imbrication method (MD -9.00 minutes, 95% CI -13.48 to -4.52).   Two trials (70 participants) compared functional mobilisation with immobilisation after surgery. These found early mobilisation led to earlier return to work (MD -2.00 weeks, 95% CI -3.06 to -0.94; 1 trial) and to sports (MD -3.00 weeks, 95% CI -4.49 to -1.51; 1 trial). Neuromuscular training alone appears effective in the short term but whether this advantage would persist on longer-term follow-up is not known. While there is insufficient evidence to support any one surgical intervention over another surgical intervention for chronic ankle instability, it is likely that there are limitations to the use of dynamic tenodesis. After surgical reconstruction, early functional rehabilitation appears to be superior to six weeks immobilisation in restoring early function.

Plain-language summary: This review includes 10 small and flawed trials that recruited a total of 388 people with chronic ankle instability. Limitations in the design, conduct and reporting of these trials meant that it was difficult to be certain that their results were valid. Three trials compared neuromuscular training with no training. These found a programme of neuromuscular training appears to provide short term improvement in functional stability. One trial testing the use of a special cycle pedal found that it did not make an important difference to function. However, none of these four trials followed-up patients after the end of treatment. Four trials compared different types of surgical intervention. There was insufficient evidence to strongly support any specific surgical procedure for treating chronic ankle instability. Two trials found that, after surgical reconstruction, early functional rehabilitation enabled patients to return to work and sports quicker than six weeks immobilisation.