Clinical and Radiological Outcomes After PHILOS Locking-Plate Fixa-tion of Proximal Humeral Fractures: A Prospective Observational Study from a Tertiary Care Centre in South India

Abstract

Background: Proximal humeral fractures are common injuries in adults and may produce persistent pain, stiffness and loss of shoulder function when displaced. Pre-contoured locking plates such as the Proximal Humeral Internal Locking System (PHILOS) are designed to provide angular stability while permitting early mobilization. This prospective observational study evaluated the clinical and radiological outcomes of PHILOS plate fixation for displaced proximal humeral fractures treated at a tertiary care centre in South India. Methods: Twenty adults with proximal humeral fractures fulfilling the study criteria underwent open reduction and internal fixation using a PHILOS plate through a conventional deltopectoral approach between March 2025 and March 2026. Fractures were classified using the Neer and AO/OTA systems. Clinical outcome was assessed using the 100-point Constant–Murley Score (CMS), including pain, activities of daily living, range of motion and strength-related components. Serial radiographs were used to assess reduction, alignment, fracture union and implant-related complications. Descriptive statistics and linear regression were used to explore factors associated with the total functional score. Results: The study included 15 men (75%) and 5 women (25%); the reported mean age was 47.8 years. Twelve fractures (60%) involved the right shoulder and 8 (40%) the left. Indirect trauma accounted for 14 cases (70%). By Neer classification, 9 fractures (45%) were two-part, 10 (50%) three-part and 1 (5%) four-part. The mean total CMS was 87.85±4.96 (median 89; range 72–95). Mean domain scores were 18.5 for activities of daily living, 9.4 for forward flexion, 8.2 for abduction, 8.3 for external rotation and 8.0 for internal rotation. Forward-flexion category was independently associated with total CMS in the reported regression model (B versus A, p=0.01; C versus A, p<0.001). Seventeen patients (85%) had no recorded postoperative complication in the detailed complication account; four had shoulder stiffness/discomfort (20%) and one had malunion (5%). No wound infection, vascular injury, loss of fixation or non-union was reported. Conclusion: In this small prospective series, PHILOS fixation was associated with satisfactory functional recovery and radiographic healing in adults with displaced proximal humeral fractures. The results support careful fracture reduction, accurate plate positioning, appropriate screw placement and structured rehabilitation. The small sample size and single-centre design limit generalizability, and larger prospective studies with standardized follow-up are required. Keywords: proximal humeral fracture, PHILOS plate, locking plate, open reduction and internal fixation, Constant–Murley Score, shoulder function, radiological union, complications