Clinical results of coracoacromial ligament transfer in acromioclavicular dislocations: A review of published literature.

Acromioclavicular joint dislocations are common injuries, which typically occur with trauma in young men. Treatment recommendations for these injuries are highly variable and controversial. There are greater than 100 surgical techniques described for operative treatment of this injury. One of the most widely recommended methods of surgical reconstruction for acromioclavicular joint dislocations is to utilize the coracoacromial ligament for stabilization of the distal clavicle. Several modifications of this procedure have been described which have involved adjunct coracoclavicular fixation or fixation across acromioclavicular joint. Although the literature is replete with descriptive papers, there is paucity of studies evaluating the surgical outcome of this procedure. We systematically reviewed the English language published literature in peer reviewed journals (Medline, EMBASE, SCOPUS) and assigned a level of evidence for available studies. We critically reviewed each paper for the flaws and biases and then evaluated the comparable clinical outcomes for various procedures and their modifications. The published literature consists entirely of case series (Level IV evidence) with variability in surgical technique and outcome measures. On review there is low level evidence to support the use of coracoacromial ligament for acromioclavicular dislocation but it has been associated with high rate of deformity recurrence. Adjunct fixation does not improve clinical results when compared to isolated coracoacromial ligament transfer. This is in part because of the high incidence of fixation related complications. Similar results are reported with coracoacromial ligament reconstruction for acute and chronic cases. The development of secondary acromioclavicular joint symptoms with distal clavicle retention is poorly reported with the incidence rate varying from 12% to 32%. Despite this, the retention or excision of distal clavicle did not affect overall clinical results except in the patients with pre existing acromioclavicular joint osteoarthritis who have inferior results with retention of distal end of clavicle. Further well designed clinical trials with validated outcome measures are required to fully evaluate the clinical results of this procedure.