Abstract
BACKGROUND: The incidence of reduction loss after locking compression plate (LCP) fixation in the treatment of proximal humerus fractures (PHFs) is higher. It can severely compromise postoperative shoulder function and, in severe cases, necessitating secondary revision surgery. This study aims to determine the risk factors for reduction loss following PHFs after LCP fixation and establish a comprehensive nomogram to guide clinical decision-making. METHODS: We retrospectively included data from adult patients with PHFs who underwent LCP fixation at our institution between January 2010 and July 2023 and met the inclusion criteria. Univariate and multivariate logistic regression analyses were conducted to evaluate the influence of potential risk factors. Independent risk factors were used to develop a nomogram model. The predictive ability and consistency of the model were evaluated by the concordance index (C-index) and the calibration curve. Decision curve analysis (DCA) was performed to assess the clinical benefit of the nomogram. RESULTS: Ultimately, 211 cases of reduction retention (RR) and 20 cases of reduction loss (RL) were finally included. Patients in RL group were notably older, with more severe Neer's classifications and with more radiological risk factors for complications. Head-splitting fractures, low cortical bone thickness, and failure to achieve anatomical reduction were identified as independent risk factors for RL. Based on these findings, we constructed a nomogram model. Our nomogram model demonstrated a strong predictive performance with a low mean absolute error and high potential significant clinical value. CONCLUSIONS: Head-splitting fractures, low cortical bone thickness, and failure to achieve anatomical reduction should be recognized as risk factors for RL in patients with PHFs following LCP fixation. Our nomogram model could effectively assist clinicians in identifying high-risk patients, potentially enabling changes in clinical practice to prevent this complication. For this purpose, further studies should be conducted to assess its external validity.