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

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.