Effectiveness of intramedullary nailing vs. locked plating (open reduction and internal fixation) in adult displaced proximal humerus fractures: a systematic review and meta-analysis

Proximal humerus fractures (PHFs) are becoming more common, especially among older adults, and often require surgical management. Two widely used surgical techniques are intramedullary nailing (IMN) and locking plate fixation (open reduction and internal fixation), yet there is ongoing debate regarding their comparative effectiveness. This study aims to systematically evaluate and compare functional, clinical, and complication-related outcomes of IMN and plating for adult patients with displaced PHFs. A systematic review and meta-analysis was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines (PROSPERO registration: CRD42023434897). We searched the databases PubMed, Embase (Ovid), and SCOPUS up to January 2025. Randomized controlled trials and cohort studies comparing IMN and plating with a minimum of 6 months' follow-up were included. The outcomes assessed were functional scores (Disabilities of Arm, Shoulder and Hand, American Shoulder and Elbow Surgeons, Constant-Murley), pain (visual analog scale), range of motion (external rotation and forward flexion), complications, and reoperation rates. We used a random-effects model to account for interstudy heterogeneity, and risk of bias was assessed using Cochrane Risk of Bias 2 and Methodological Index for Nonrandomized Studies tools. After screening, 12 studies (n = 1,039 participants; mean age 65.6 years) were included. Amongst these, we found no statistically significant differences between IMN and plating in Disabilities of Arm, Shoulder and Hand, American Shoulder and Elbow Surgeons, or Constant-Murley scores at 6 months. Visual analog scale pain scores, range of motion, complication rates, and reoperation rates were also comparable. Subgroup analysis for 2-part, 3-part fractures, and at 12 months follow-up also revealed no significant outcome differences between techniques. While some individual studies showed small short-term advantages favoring one method, these did not exceed thresholds for clinical relevance. Evidence quality was moderate overall, with some heterogeneity in study design, outcome reporting, and follow-up duration. We found that IMN and plating demonstrate equivalent clinical outcomes for the surgical management of displaced PHFs in adults. We suggest, therefore, that IMN may represent a reasonable alternative to plating, given its reduced operative time, less soft tissue disruption, and lower overall cost. However, further research is needed to determine whether specific patient subgroups benefit more from one technique.