MIPO versus nailing for humeral shaft fractures: a meta-analysis and systematic review of randomised clinical trials and observational studies

Purpose: There is no consensus on the optimal operative technique for humeral shaft fractures. This meta-analysis aims to compare minimal-invasive plate osteosynthesis (MIPO) with nail fixation for humeral shaft fractures regarding healing, complications and functional results. Methods: PubMed/Medline/Embase/CENTRAL/CINAHL were searched for randomized clinical trials (RCT) and observational studies comparing MIPO with nailing for humeral shaft fractures. Effect estimates were pooled across studies using random effects models and presented as weighted odds ratio (OR), risk difference (RD), mean difference (MD) and standardized mean difference (SMD) with corresponding 95% confidence interval (95%CI). Analyses were repeated stratified by study design (RCTs and observational studies). Results: A total of 2 RCTs (87 patients) and 5 observational studies (595 patients) were included. The effects estimated in observational studies and RCTs were similar in direction and magnitude for all outcomes except operation duration. MIPO has a lower risk for non-union (RD 7%; OR 0.2, 95% CI 0.1–0.5) and re-intervention (RD 13%; OR 0.3, 95% CI 0.1–0.8). Functional shoulder (SMD 1.0, 95% CI 0.2–1.8) and elbow scores (SMD 0.4, 95% CI 0–0.8) were better among patients treated with MIPO. The risk for radial nerve palsy following surgery was equal (RD 2%; OR 0.6, 95% CI 0.3–1.2) and nerve function recovered spontaneously in all patients in both groups. No difference was detected with regard to infection, time to union and operation duration. Conclusion: MIPO has a considerable lower risk for non-union and re-intervention, leads to better shoulder function and, to a lesser extent, better elbow function compared to nailing. Although nailing appears to be a viable option, the evidence suggests that MIPO should be the preferred treatment of choice. The learning curve of minimal-invasive plating should, however, be taken into account when interpreting these results.