What is the optimal implant removal timing following hook plate fixation in distal clavicle fractures: a retrospective analysis from subacromial osteolysis cases

Clavicular hook plates are widely used for the fixation of distal clavicle fractures, yet prolonged retention of the hook plate is associated with subacromial osteolysis (SAO), a common complication that may lead to poor functional outcomes. The optimal timing for implant removal remains unclear. This retrospective study aims to identify the predictive factors for SAO and determine the optimal timing for implant removal that balances the prevention of complications with sufficient fracture healing. This retrospective review was conducted on 92 patients who underwent hook plate fixation for displaced distal clavicle fractures between 2018 and 2024. Radiographic and clinical data were analyzed to assess the association between SAO development and various factors, including fracture classification, plate positioning factors, and implant retention time. Logistic regression and ROC curve analyses were used to identify independent risk factors and determine the optimal timing for implant removal. SAO was observed in 65% of patients (n = 60) following hook plate fixation. Multivariate analysis revealed that Neer Type IIb (OR: 5.63, p = 0.040) and Type V fractures (OR: 16.23, p = 0.014) were significantly associated with increased SAO risk. Implant retention beyond 5.3 months markedly elevated the risk (OR: 19.75, p < 0.001). ROC analysis yielded an AUC of 0.832, indicating excellent predictive accuracy. Severity of SAO also correlated with fracture type, particularly with Type IIb and V patterns. Prolonged implant retention and higher-grade fracture types significantly increase the risk of SAO after hook plate fixation. To reduce SAO incidence and improve outcomes, we recommended removal of the hook plate within 5.3 months postoperatively after confirmation of radiographic and clinical union, particularly in patients with Neer Type IIb or V fractures.