Risk factors for osteonecrosis of the humeral head after internal fixation of proximal humeral fractures: a systematic review and meta-analysis.

BACKGROUND

Osteonecrosis of the humeral head (ONHH) is a severe complication after the internal fixation of proximal humeral fractures (IFPHF). The risk factors remain controversial though many studies have reported. In this research, meta-analysis was used to evaluate which surgeon-level factors can be modified to lower the risk and we hope to provide evidence-based support for preventing ONHH.

METHODS

Literature was retrieved from PubMed, Cochrane Library, Embase, Web of Science, and Scopus for eligible studies published up to January 2023. The pooled odds ratios (ORs) were calculated with their corresponding 95% confidence intervals (CIs) to evaluate. STATA 15.1 software was applied for data synthesis, sensitivity synthesis, and publication bias.

RESULTS

45 articles were published between 2000 and 2022, and 2482 patients were finally included. All articles were observational research, with 7 case-control studies and 38 cohort studies, and the Newcastle Ottawa Scale (NOS) score ranged from 7 to 9. The pooled results suggested that age (OR 0.32, 95% CI 0.14-0.74, P = 0.01), reduction quality (OR 0.08, 95% CI 0.01-0.44, P = 0.00), fracture type (OR 0.44, 95% CI 0.25-0.78, P = 0.01), surgical approach (OR: 4.06, 95% CI 1.21-13.61, P = 0.02) and fixation implant (OR = 0.68, 95% CI = 0.34-1.33, P = 0.02) were risk factors for ONHH after IFPHF. According to sensitivity analysis, Begg (P = 0.42) and Egger (P = 0.68) tests, the results were stable and exhibited no publication bias.

CONCLUSIONS

The study showed that age, reduction quality, fracture type, surgical approach and fixation implant were risk factors for ONHH after IFPHF, while gender, varus or valgus, timely operation, injured side, and the existence of medial support have little influence on ONHH, as they could not be considered risk factors and still need further investigations.