Comparative Efficacy of Anterior MIPO with PHILOS versus Posterior ORIF with EA-LCP in Distal Third Humerus Fractures: A Randomized Controlled Trial.

OBJECTIVES: To compare anterior minimally invasive plate osteosynthesis (MIPO) using the proximal humerus internal locking system (PHILOS) in an upside-down reverse configuration with conventional posterior open reduction and internal fixation (ORIF) using extra-articular locking compression plate (EA-LCP) for the treatment of extra-articular distal-third humeral shaft fractures.

METHODS: Design: Prospective randomized controlled trial.

SETTING: Single Level 1 trauma center (New Delhi, India).

PATIENT SELECTION CRITERIA: Adult patients aged 18-55 years with extra-articular distal third humeral shaft fractures (AO/OTA types 12A-C) presenting within 2 weeks of injury were randomized to undergo anterior MIPO or posterior ORIF.

OUTCOME MEASURES AND COMPARISONS: Radiological union, functional outcomes [Mayo Elbow Performance Score (MEPS), University of California-Los Angeles (UCLA) shoulder rating scale] and elbow range-of-motion (ROM) were assessed and compared at 2 weeks, 6 weeks, 3 months and 6 months post-operatively. Operative time, intraoperative blood loss, radiation exposure, post-operative pain (VAS scores) and complications were also compared.

RESULTS: Thirty patients were included (anterior MIPO, n=14; posterior ORIF, n=16). Mean age was 27.9 years (range 18-55) in the MIPO group and 29.8 years (range 19-48) in the ORIF group, p=0.598. There were 11 males and 3 females in the MIPO group and 11 males and 5 females in the ORIF group, p=0.68. Mean time to radiological union was shorter in the MIPO group (16.3 ± 1.3 weeks) compared to the ORIF group (18.1 ± 1.2 weeks, p=0.001). Operative time was shorter in the MIPO group (78.9 ± 24.4 min vs 112.6 ± 42.0 min, p=0.013), intraoperative blood loss was lower (182.1 ± 137.4 mL vs 328.1 ± 96.8 mL, p=0.002) and immediate post-operative pain on day 2 was lower (VAS, 7 ± 0.5 vs 8 ± 0.6, p<0.001). Functional outcomes showed no statistically significant differences between groups at 6 months (MEPS: 100 vs 100 p=1.000; UCLA: 33.8 ± 0.3 vs 33.7 ± 0.4, p=0.636) with no statistically significant difference in elbow ROM (137.8 ± 2.5° vs 135.4 ± 3.0°, p=0.192). Radiation exposure was higher in the MIPO group (1.5 ± 1.0 mGy vs 0.3 ± 0.5 mGy, p=0.003). Post-operative radial nerve palsy occurred in one patient in the MIPO group and three in the ORIF group, with complete recovery in all cases. Nonunion occurred in one patient in each group, both of whom required revision surgery.

CONCLUSIONS: Anterior MIPO using a reverse PHILOS was associated with shorter time to radiological union, lower intraoperative morbidity and no statistically significant differences in functional outcomes compared to posterior ORIF for patients with extra-articular distal humerus fractures. It was a viable and effective alternative for managing distal third humeral shaft fractures.

LEVEL OF EVIDENCE: Therapeutic Level I.