Comparison of Different Coracoclavicular Stabilization Techniques in Acute Acromioclavicular Injury With Augmented Acromioclavicular Ligament Repair: A Whole-Body Cadaveric Study

Abstract

Background: Acute acromioclavicular (AC) joint injuries account for approximately half of all shoulder injuries in sports trauma, and the optimal surgical strategy remains controversial. Contemporary surgical management increasingly combines coracoclavicular (CC) stabilization with augmented AC ligament repair. However, the relative kinematic performance of different CC stabilization techniques in the presence of AC repair has not been previously investigated. Purpose: To compare 3 CC stabilization techniques—coracoclavicular loop, single clavicular tunnel, and double clavicular tunnel—each combined with double-row AC ligament repair, to determine which technique most closely restores physiologic scapular and clavicular motion. Study Design: Controlled laboratory study. Methods: Eight shoulders from 4 fresh-frozen whole-body cadavers were assessed. Each shoulder was passively taken through forward flexion, abduction, and horizontal adduction by a single operator at a standardized cadence, while 3-dimensional scapular and clavicular motions were recorded using an inertial measurement unit–based system. Kinematics were evaluated under intact conditions, after sequential ligament transections, and following each reconstruction technique, analyzed using mixed-effects models and polynomial regression. Results: Significant kinematic deviations were observed following AC and CC ligament transection, particularly beyond 120° of elevation. None of the techniques fully restored native motion. The double-tunnel construct showed the smallest deviation from intact scapular external rotation, while all 3 repair techniques produced similar reductions in clavicular motion. The single-tunnel construct showed the greatest deviation, while the loop technique produced intermediate results. All reconstructions showed persistent scapular rotation increases and reduced clavicular dynamics at higher elevation angles. Conclusion: When combined with AC ligament repair, the double-tunnel CC stabilization most closely approximated physiologic scapular and clavicular motion. However, kinematic deviations beyond 120° of arm elevation suggest a zone of mechanical vulnerability across all techniques. Clinical Relevance: Among the 3 CC stabilization techniques tested with concurrent AC ligament repair, the double-tunnel construct most closely restored physiologic scapular and clavicular motion and may be considered the preferred technique. Surgeons may consider restricting arm elevation to <120° during early rehabilitation, as kinematic deviations beyond this range may reflect patterns consistent with scapular dyskinesis.