Surgical outcomes of the coracoid process fracture associated with the acromioclavicular joint injury in Korea: a case series

Background: Excluding technical reports and isolated case reports, there are no published studies evaluating coracoid process fixation with or without an acromioclavicular joint (ACJ) stabilization procedure for coracoid process fractures associated with ACJ injury. The purpose of this study was to assess the surgical outcomes of coracoid process fractures associated with ACJ injuries and to determine the usefulness of coracoid process fixation with or without an ACJ stabilization procedure.Methods: From February 2006 to December 2015, patients with coracoid process fractures associated with ACJ injuries were enrolled. Radiological and clinical outcomes were analyzed in 12 patients who underwent coracoid process fixation with or without an ACJ stabilization procedure. A 3.5-mm cannulated screw with a washer or a 3.0-mm headless compression screw was used for coracoid process fixation, and either a clavicle hook plate or Kirschner (K)-wires were used for ACJ injuries when additional fixation was necessary.Results: Bone union was achieved in 11 patients (91.7%), while one case was determined to be a nonunion at 6 months. Radiological union occurred at an average of 3 months (range, 1.5–4 months) in all patients except the nonunion case. At the final follow-up, the average clinical scores were a visual analogue scale (VAS) pain score of 1.5 (range, 0–4) and a UCLA score of 30.9 (range, 28–35). Clinical outcomes were satisfactory in all patients, including the patient with nonunion.Conclusion: The clinical and radiological outcomes of treating coracoid process fractures associated with ACJ injuries using coracoid process fixation with or without ACJ stabilization were favorable. A cannulated screw with a washer and clavicle hook plate fixation may provide sufficient stability for both the coracoid process fracture and the ACJ injury when feasible.Level of evidence: IV.