Abstract: We included three randomised controlled trials, involving a total of 251 participants. All three trials were at high risk of performance bias reflecting the fact that surgeons could not be blinded. One trial was at low risk of selection bias but was undermined by a high attrition bias, in part resulting from post-randomisation exclusions. There were incomplete details of methodology for the other two trials, which usually resulted in unclear risk of bias judgements. Two trials compared radial head replacement with open reduction and internal fixation (ORIF) for treating Mason type III radial head fractures. The trial authors reported outcomes at a mean of 2.8 years and 15 months respectively. There were significant differences between the two groups in favour of radial head replacement in the Broberg and Morrey elbow scores (92.1 versus 72.4, mean difference (MD) 19.70; 95% confidence interval (CI) 15.64 to 23.76; one trial, 45 participants), excellent or good Broberg and Morrey elbow scores (33/36 versus 16/31, risk ratio (RR) 1.88; 95% CI 1.27 to 2.77; two trials), and overall adverse events (6/36 versus 15/31, RR 0.33; 95% CI 0.14 to 0.77; two trials). No statistically significant difference was found between the two groups in any of the reported individual adverse events. One trial compared biodegradable pins with standard metal screws in treating radial head fractures of AO-classification 21 B2. The two types of fixation devices yielded similar results, with no significant between-group differences in the Broberg and Morrey scores (93.3 versus 90.9, MD 2.40; 95% CI -0.10 to 4.90), excellent or good Broberg and Morrey elbow scores (72/74 versus 56/61, RR 1.06; 95% CI 0.97 to 1.15), and adverse events (13/82 versus 16/82, RR 0.81; 95% CI 0.42 to 1.58) at two-year follow-up. Only tentative conclusions can be drawn from the available evidence in this review. Compared with ORIF, there was some evidence that radial head replacement had better elbow function and fewer adverse events for Mason type III radial head fractures in the short term. However, the evidence is of low quality and it is unknown whether these results would apply in the longer term or more generally. Using biodegradable implants may be as good as metallic implants for fixation of some usually more stable fractures but more evidence is needed to confirm this. There is a need for good quality evidence for addressing the areas of uncertainty for the surgical treatment of radial head fractures.

Plain-language summary: This review includes evidence from three randomised controlled trials with a total of 251 participants. All three trials were at some risk of bias, which means that their results may not be reliable. Two trials compared radial head replacement with ORIF for treating highly fragmented radial head fractures. These trials showed that after radial head replacement, patients had significantly better elbow function and fewer adverse events than those treated with ORIF at between one and three years follow-up. One trial compared biodegradable pins with standard metal screws in treating displaced radial head fractures. It found similar results for the two types of materials in terms of elbow function and adverse events. Overall, there is some evidence to support radial head replacement for treating highly fragmented radial head fractures instead of attempting to fix the fractured bone back in place. However, the evidence is low quality and it is unknown whether these results would apply in the longer term or more generally. Using biodegradable implants may be as good as metallic implants for fixing some usually more stable fractures but more evidence is needed to confirm this.