MIPO versus ORIF with long proximal humerus locking plate for metadiaphyseal proximal humeral fracture.

BACKGROUND: This study aimed to compare ORIF (open reduction internal fixation) and MIPO (minimal invasive plate osteosynthesis) using long PHLP (proximal humerus locking plate) in treating metadiaphyseal proximal humeral fractures regarding time to union, complications, and clinical outcomes. METHODS: This retrospective study was conducted at a single-center Level 1 trauma facility. The study population consisted of patients who underwent long PHLP fixation for metadiaphyseal proximal humeral fractures and completed a minimum follow-up of 1 year. Patients with additional injuries in the same extremity, those treated with implants other than long PHLP, or those managed with surgical techniques other than MIPO or ORIF were excluded. The cohort was divided into two groups: MIPO (32 patients) and ORIF (29 patients). The groups were compared with respect to demographic characteristics (age, sex, mechanism of trauma), radiological outcomes (time to union), and clinical outcomes, including the Disabilities of the Arm, Shoulder and Hand (DASH) score, Constant-Murley score, and complication rates. RESULTS: The mean age was 54.96 (SD 17.1, range 24-85) in the MIPO group and 54.55 (SD 15.03, range 22-84) in the ORIF group. The MIPO group (n = 32) had a significantly shorter mean time to union than the ORIF group (n = 29) 13.8 ± 3.0 vs. 17.3 ± 5.1 weeks; p = 0.003. At 1 year, DASH scores were lower in the MIPO group 8.6 ± 7.1 vs. 12.8 ± 8.8; p = 0.044. Constant-Murley scores showed no significant difference between groups 87.8 ± 6.2 vs. 84.5 ± 9.0; p = 0.094. In the MIPO group, 1 (3.1%) patient had radial nerve impairment and 1 (3.1%) patient had subacromial impingement; in the ORIF group, 1 (3.4%) patient had radial nerve impairment and 2 (6.9%) patients had nonunion. CONCLUSION: In metadiaphyseal proximal humeral fractures, minimally invasive plate osteosynthesis using a long proximal humeral locking plate was associated with a shorter radiographic time to union than open reduction and internal fixation, although this finding should be interpreted in the context of the different radiographic union criteria applied in the two groups. LEVEL OF EVIDENCE: III.