Acromioclavicular joint augmentation at the time of coracoclavicular ligament reconstruction fails to improve functional outcomes despite significantly improved horizontal stability.

PURPOSE: Acromioclavicular joint reconstruction is a well-established and frequently performed procedure. Recent scientific and commercial interest has led to a drive to develop and perform surgical techniques that more reliably restore horizontal stability in order to improve patient outcomes. The aim of this systematic review was to evaluate the biomechanical evidence for procedures directed at restoring horizontal stability and determine whether they are associated with superior clinical results when compared to well-established procedures.
METHODS: A review of the online databases Medline and EMBASE was conducted in accordance with the PRISMA guidelines on the 23rd December 2017. Biomechanical and clinical studies reporting either static or dynamic horizontal displacement following acromioclavicular joint reconstruction (Coracoclavicular reconstruction or Weaver-Dunn) were included. In addition, biomechanical and clinical studies reporting outcomes after additional augmentation of the acromioclavicular joint were included. The studies were appraised using the Methodological index for non-randomised studies tool.
RESULTS: The search strategy identified 18 studies eligible for inclusion: six biomechanical and 12 clinical studies. Comparative biomechanical studies demonstrated that acromioclavicular augmentation provided significantly increased horizontal stability compared to the coracoclavicular reconstruction and Weaver-Dunn procedure. Comparative clinical studies demonstrated no significant differences between coracoclavicular reconstruction with and without acromioclavicular augmentation in terms of functional outcomes (American Shoulder and Elbow Surgeon and Constant score), complication or revision rates. However, one comparative study did demonstrate an improvement in Taft (p = 0.018) and Acromioclavicular Joint Instability scores (p = 0.0001) after acromioclavicular augmentation.
CONCLUSION: In conclusion, coracoclavicular reconstruction with augmentation of the acromioclavicular joint has been shown to provide improved horizontal stability in both biomechanical and clinical studies compared to isolated coracoclavicular reconstruction. However, comparative studies have shown no clinical advantage with respect to American Shoulder and Elbow Surgeon or Constant scores and, therefore, the results of this systematic review do not support acromioclavicular augmentation in routine clinical practice. LEVEL OF EVIDENCE: IV.