Minimally invasive plate osteosynthesis, open reduction and plate fixation, and intramedullary nailing for humeral shaft fractures: A network meta-analysis of randomized controlled trials.

BACKGROUND: The optimal surgical technique for humeral shaft fractures remains debated, and earlier syntheses often pooled all plate constructs, disregarding the distinction between open reduction and plate fixation (ORPF) and minimally invasive plate osteosynthesis (MIPO). This network meta-analysis compared ORPF, MIPO, and intramedullary nailing (IMN), focusing on iatrogenic radial nerve injury.

METHODS: We searched PubMed/MEDLINE, Embase, Cochrane CENTRAL, and Scopus from inception through December 2024, with the PubMed search updated through January 2026, following the PRISMA network meta-analysis extension (PROSPERO CRD420261321547). Randomized controlled trials comparing at least two of the three techniques in adults with closed diaphyseal humeral fractures were eligible. The primary outcome was iatrogenic radial nerve injury; secondary outcomes were nonunion, deep infection, and reoperation. A frequentist random-effects network model estimated odds ratios (OR) with 95% confidence intervals. Treatments were ranked using the surface under the cumulative ranking curve (SUCRA), which orders treatments by estimated effect and is not an absolute event rate.

RESULTS: Twelve RCTs (647 patients) met the criteria for the primary network; three non-randomized or non-comparable studies were reserved for sensitivity analysis. MIPO was associated with lower odds of radial nerve injury than ORPF (OR 0.21, 95% CI 0.05-0.88; P = 0.033) and with lower odds of reoperation than ORPF (OR 0.18, 95% CI 0.05-0.58) and IMN. IMN carried higher odds of nonunion than MIPO (OR 4.82, 95% CI 1.18-19.74), from a single direct trial. Heterogeneity was absent (I-squared 0%) with no significant inconsistency. SUCRA values for radial nerve safety were 91% (MIPO), 56% (IMN), and 4% (ORPF). The primary finding persisted when non-randomized studies were added, but its significance depended on two middle-to-distal trials in leave-one-out analysis.

CONCLUSIONS: For closed diaphyseal humeral fractures, MIPO appears to be associated with a lower risk of iatrogenic radial nerve injury and reoperation than ORPF, and it ranked favorably across complications. Because direct MIPO comparisons are few and confidence intervals wide, these associations should inform rather than dictate technique selection and warrant confirmation in powered trials.

REGISTRATION: This review was registered in PROSPERO (CRD420261321547).

LEVEL OF EVIDENCE: Therapeutic Level I.