The “coracoid tunnel view”: a simulation study for finding the optimal screw trajectory in coracoid base fracture fixation

PURPOSE: Coracoid fractures represent approximately 3–13% of all scapular fractures. Open reduction and internal fixation can be indicated for a coracoid base fracture. This procedure is challenging due to the nature of visualization of the coracoid with fluoroscopy. The aim of this study was to develop a fluoroscopic imaging protocol, which helps surgeons in finding the optimal insertion point and screw orientation for fixations of coracoid base fractures, and to assess its feasibility in a simulation study. METHODS: A novel imaging protocol was defined for screw fixation of coracoid base fractures under fluoroscopic guidance. The method is based on finding the optimal view for screw insertion perpendicular to the viewing plane. In a fluoroscopy simulation environment, eight orthopaedic surgeons were invited to place a screw down the coracoid stalk through the coracoid base and into the neck of 14 cadaveric scapulae using anatomical landmarks. The surgeons placed screws before and after they received an e-learning of the optimal view. Results of the two sessions were compared and inter-rater reliability was calculated. RESULTS: Screw placement was correct in 33 out of 56 (58.9%) before, and increased to 50 out of 56 (89.3%) after the coracoid tunnel view was explained to the surgeons, which was a significant improvement (p < 0.001). CONCLUSIONS: Our newly developed fluoroscopic view based on simple landmarks is a useful addendum in the orthopaedic surgeon’s tool box to fixate fractures of the coracoid base. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00276-019-02274-z) contains supplementary material, which is available to authorized users.