Objective: Current X-ray-based classification methods cannot describe all distal clavicle fracture (DCF) patterns, especially the osteoligamentous injury pattern of DCFs. We aimed to develop a novel classification based on the osteoligamentous injury pattern of the DCFs and investigated its reliability.
Methods: All DCFs from January 2017 to January 2022 were respectively screened and 45 cases (mean age 20-78; male 31, female 14) met the including criteria and were enrolled. Based on their Zanca view X-ray radiograph and three-dimensional CT construction images, we analyzed the osteoligamentous injury pattern of each case, particularly the acromioclavicular (AC) and coracoclavicular ligaments and their bone attachment. Then we developed a novel classification method, five types in total, sorting all DCFs according to their lesion manifestations of osteoligamentous complex. Also, we investigated the inter- and intra-observer reliability using kappa value.
Results: A novel classification method for DCF was developed, manifesting the avulsion or rupture of conoid and trapezoid ligaments, and involvement of AC joint. Forty-five cases of DCFs were included in this study. Among them, 11 (24.4%) were Type 1 fracture, three (6.7%) cases were Type 2, six cases (13.3%) were Type 3, 21 (46.7%) were Type 4, four (8.9%) were Type 5. Kappa values for inter-observer agreement were 0.57 after first evaluation and 0.61 after second evaluation. Intra-observer agreement was 0.72 for experienced shoulder specialist and 0.63 for radiologist.
Conclusion: This new classification method is reliable to use, supplementary to current classification systems, and emphasizes on the osteoligamentous complex injury when opting for the treatment.
Keywords: Classification; Distal Clavicle Fractures; Osteoligamentous Complex.
© 2022 The Authors. Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.