Clinical Impact of Malunion After All-Arthroscopic Coracoclavicular Stabilization for Displaced and Unstable Lateral Clavicle Fractures.

Abstract

To evaluate the clinical outcome of lateral clavicle malunion treated with all-arthroscopic coracoclavicular (CC) stabilization. Retrospective, case series. Department of hand and upper extremity surgery, university hospital center. Forty-five patients with unstable and displaced lateral clavicle fracture treated between January 2015 and August 2019 were included in the study. Closed reduction and arthroscopic CC stabilization using cortical buttons. Shoulder pain and active motion. Patient-reported outcome measures included the Constant score, the Subjective Shoulder Value, the AcromioClavicular Joint Instability score, and the Specific AcromioClavicular Score. Radiographic evaluation assessed bony union and malunion. Mean duration of follow-up was 25 months (12-60 months). Five patients (11%) had lateral clavicle nonunion and 7 (16%) had lateral clavicle malunion (5 in the coronal plane and 2 in the axial plane). Lateral clavicle malunion did not significantly affect clinical or functional outcomes (P > 0.05). Mean active shoulder motion was forward flexion 163 degrees (SD 28), abduction 162 degrees (SD 26), and external rotation 63 degrees (SD 21). On average, the patients scored 88.3 (SD 17.7) in the Constant score, 90% (SD 12) in the Subjective Shoulder Value, 88.8 (SD 9.4) in the AcromioClavicular Joint Instability score, and 11.4 (SD 8.5) for SACS. The overall complication rate was 38% (including 7 malunions, 5 nonunions, 2 adhesive capsulitis, and 3 button malpositions). Closed reduction and internal fixation of lateral clavicle fracture with all-arthroscopic CC stabilization using cortical button potentiates bony union but may generate lateral clavicle malunion, which does not affect the clinical or functional outcome. This result can be attributed to CC ligament healing and acromioclavicular joint congruence. All-arthroscopic CC stabilization is a minimally invasive but demanding surgical alternative for managing unstable and displaced lateral clavicle fracture. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.