The effects of augmentation choices for locking plate fixation in proximal humerus fracture osteosynthesis: a systematic review and meta-analysis.

Background: Various augmentation choices have been reported to improve outcomes following locking plate fixation for proximal humerus fracture, but their effectiveness and safety are still under investigation. This study aims to investigate the effects of augmentation choices, including bone grafts, cement, and intramedullary plates, in locking plate fixation for proximal humerus fractures.

Methods: PubMed, Embase, and Cochrane Library were searched for studies up to April 2024. A random-effects meta-analysis was performed within a frequentist framework.

Results: A total of 35 studies, comprising 6 randomized controlled trials and 29 nonrandomized studies of intervention with a total of 37,494 patients, were included in this review. After adjusting for small-study bias, locking plate fixation with bone grafts or cement did not affect overall complication risk (risk ratio [RR]: 1.03, 95% confidence interval [CI] 0.74-1.45), the screw protrusion risk (RR: 0.74, 95% CI 0.45-1.13), and the avascular necrosis risk (RR: 0.98, 95% CI 0.73-1.32) compared with locking plates alone. Augmentation showed small-to-moderate effects on pain reduction and functional improvement and reduced changes in humeral head height and neck-shaft angle. In subgroup analyses, cement augmentation, while possibly inferior to bone grafts in pain relief and function, showed comparable effects on radiographic outcomes. No significant difference between strut fibular and non-fibular grafts was observed.

Conclusions: Augmentation with bone grafts or cement does not convincingly reduce complication risks or screw protrusion compared with locking plate fixation alone. However, it improves pain, function, and radiographic outcomes in osteosynthesis of proximal humerus fractures.

Level of evidence: II.

Registration: CRD42024500403.