Coracoclavicular Ligament Reconstruction

Operative intervention is recommended for complete acromioclavicular (AC) joint dislocation to restore AC stability, but the best operative technique is still controversial. Twelve fresh-frozen male cadaveric shoulders (average age, 62.8 7.8 years) were equally divided into endobutton versus the modified Weaver-Dunn groups. Each potted scapula and clavicle was fixed in a custom made jig to allow translation and load to failure testing using a Zwick BZ2.5/TS1S material testing machine (Zwick/Roell Co, Germany). A systematic review of 21 studies evaluating reconstructive methods for coracoclavicular or AC joints using a cadaveric model was also performed. From our biomechanical study, after ligament reconstruction, the triple endobutton technique demonstrated superior, anterior, and posterior displacements similar to that of the intact state (P> 0.05). In the modified Weaver-Dunn reconstruction group, however, there was significantly greater anterior (P< 0.001) and posterior (P1⁄4 0.003) translation after ligament reconstruction. In addition, there was no significant difference after reconstruction between failure load of the triple endobutton group and that of the intact state (686.88 vs 684.9 N, P> 0.05), whereas the failure load after the modified Weaver-Dunn reconstruction was decreased compared with the intact state (171.64 vs 640.86 N, P< 0.001). From our systematic review of 21 studies, which involved comparison of the modified Weaver-Dunn technique with other methods, the majority showed that the modified Weaver-Dunn procedure had significantly (P< .05) greater laxity than other methods including the endobutton technique. The triple endobutton reconstruction proved superior to the modified Weaver-Dunn technique in restoration of AC joint stability and strength. Triple endobutton reconstruction of the coracoclavicular ligament is superior to the modified Weaver-Dunn reconstruction in controlling both superior and anteroposterior displacements with a failure load that D, and Yun-feng Chen, MD, PhD Abbreviations: AC = acromioclavicular, CA = coracoacromial, CC = coracoclavicular, PDS = polydioxansulfate. INTRODUCTION A cromioclavicular (AC) joint dislocation accounts for approximately 9% of shoulder girdle injuries. These injuries are classified into type I–VI injuries on the basis of the radiographic findings using the Rockwood criteria. The Rockwood classification takes into account not only the AC joint, but also the coracoclavicular (CC) ligament (which consists of 2 fasciculi, the trapezoid and conoid ligaments), the deltoid and trapezius muscles, and the direction of dislocation of the clavicle with respect to the acromion. Most type I and type II injuries can be successfully treated nonoperatively in the majority of patients. Although Type IV through type VI injuries are treated operatively because of their severe instability, treatment for type III injury is still controversial. Most surgical procedures involving the AC joint primarily involve fixation of the joint and reconstruction of the CC ligament. AC joint fixation methods involve the use of wires, screws, and hook plates, although these techniques have significant limitations including unsatisfactory maintenance of AC joint reduction, osteolysis, and fracture as well as hardwarerelated complications. In addition, many of these procedures necessitate a second procedure for hardware removal. Several procedures for reconstruction of CC ligament have been described. The Modified Weaver-Dunn procedure is the most widely used CC reconstruction method. After resecting the distal clavicle, it involves transfer of the coracoacromial (CA) ligament (which was detached from the under surface of the acromion) together with a small piece of boneto, the distal clavicle using cerclage wires. However, postsurgical complications include persistent pain, weakness, and clavicular osteolysis. Anatomic and biomechanical studies have addressed the contributions of both CC and AC ligaments to AC joint stability. Consequently, different stabilizing procedures have been developed, which focus on reconstruction of the CC ligament, including single-bundle, double-bundle, as well as a sling-fashion reconstructions using autograft, allograft, or synthetic materials. Reconstruction of the trapezoid and conoid ligaments in independent procedures was found to be biomechanically superior. Clinical articles also report promising outcomes from such reconstruction techniques. Recently, the triple endobutton technique has been used in reconstruction of complete AC joint dislocations. This technique allows restoration of the CC ligament to be in a position as anatomical as possible with the strength of the original strength. We present our experiion of CC ligaments using the triple (Acufex; Smith & Nephew, Andover, www.md-journal.com | 1