Factors influencing surgical outcomes of fixation with locking plate for three- and four-part proximal humerus fractures in patients aged 50 ​Years and older.

Background: Treating complex three- and four-part proximal humerus fractures, especially in the elderly, remains contentious, with internal fixation using locking plates and shoulder arthroplasty being primary options. Although proximal humerus locking plates are more commonly used than shoulder replacements, they have a high complication rate. Factors like low bone density, advanced age, multiple fragment fractures, and medial cortical support loss negatively impact treatment outcomes. This study evaluates the functional and radiographic outcomes of using locking plates for treating these fractures in patients aged 50 and older, and the factors influencing outcomes and complication rates at the Ho Chi Minh City Hospital for Trauma and Orthopedics. Method: A descriptive case series study was conducted on 58 patients aged 50 and older (15 males, 43 females) with three- and four-part proximal humerus fractures. These patients underwent open reduction and internal fixation with Locking - compression plate (LCP) periarticular proximal humerus plates at the Ho Chi Minh City Hospital for Traumatology and Orthopedics (HTO) from April 2020 to April 2022. The minimum postoperative follow-up period was 12 months. Results: The average age of the patients was 62.78 â€‹± â€‹7.73 years, with a mean follow-up of 26.24 â€‹± â€‹5.93 months. Among them, 41 had three-part fractures (70.68 â€‹%) and 17 had four-part fractures (29.32 â€‹%). At the final follow-up (≥12 months), the mean Constant-Murley score was 70.81 â€‹± â€‹9.15, and the mean QDASH score was 8.33 â€‹± â€‹2.77. Complications occurred in 6 cases (10.34 â€‹%). Complex fractures, such as four-part fractures with displacement greater than 2 â€‹mm, had lower Constant-Murley scores and higher QDASH scores (p â€‹< â€‹0.05). Age, gender, bone density by deltoid tuberosity index (DTI), bone grafting, and rotator cuff sutures showed similar trends, but the differences were not statistically significant. Conclusion: Open reduction and internal fixation (ORIF) provides good bone healing and functional outcomes for three- and four-part proximal humerus fractures. Factors such as age, gender, bone density, bone grafting, and rotator cuff sutures do not significantly affect outcomes. Therefore, osteoporosis should not be a contraindication for ORIF with locking plates in these cases. Complex fractures, however, often lead to poorer outcomes and higher complication rates post-surgery.