Summary
Both anatomical and nonanatomical techniques show satisfactory pre to post-operative results in chronic acromioclavicular joint dislocation patients, with a low rate of failures and re-operations.
Abstract
Introduction
The Weaver-Dunn (WD) technique has been historically considered the standard for the treatment of chronic instability following acromioclavicular (AC) dislocation. Despite the disseminated practice of several alternative surgical techniques, there is still no consensus or even robust evidence demonstrating the superiority of them. Hence, this systematic review aims to collect and compare the outcomes of the various reconstructive surgical techniques published in literature.
Methods
A systematic review of databases Pubmed, SPORTDiscus and Cochrane Library was performed in order to include relevant studies reporting clinical, functional and radiological outcomes of AC joint reconstruction. The search collected all available studies up to the April 30 2018, and was designed by combining the following keywords: “acromio-clavicular”, “acromioclavicular”, “chronic”, “dislocation”, “sprain”, “separation” and “instability”; with resource to the Boolean operators (AND) and (OR) and the command [Ti/Ab]. Methodological quality was assessed through MINORs index. R Studio software (metafor package) was used for conducting meta-analysis with pre-to-post differences to compute Cohen’s d and metaregression to identify potential individual factors that could lead to heterogeneity.
Results
Twenty-eight studies including 779 patients (mean 36.6 yo) with symptoms of chronic instability of the AC joint for 16.3 months (3 to 39 months) were included. Through 39 different subgroups included, surgical treatment was performed either openly (n=34) or arthroscopically (n=5) and recurring to anatomical (n=21) or nonanatomical techniques (n=16; WD or modifications of WD), with the remaining 2 relating to other nonanatomic techniques. Among the anatomical techniques, the most common type of graft was synthetic (n=9) followed by autologous tendon (n=9) and allografic tendon (n=3). Within autologous grafts, the semitendinosus tendon (n=5) was the most used. Most prevalent complications were heterotopic ossification (n=63), AC arthrosis (n=42) and superficial infection (n=35), after a mean follow up of 38 months. Both anatomical and nonanatomical techniques showed significant pre-to-post improvements on the Constant score (p<.01) with an average improvement ranging from 11.1 to 50.7, but with significant publication bias. Type of grafts (autograft, allograft or synthetic), surgical approach (open vs arthroscopic), fixation technique and MINORs score were used as moderator variables in the metaregression model and did not yielded a substantial reduction on the amount of between-studies’ heterogeneity. Regardless the surgical technique, Constant score always surpassed the minimal clinically important difference and most patients reported high satisfaction, with few failures (7.6%) or re-operation rates (4.7%). More specifically, anatomical techniques seem to yield better functional outcomes, despite similar radiological outcomes between anatomical and nonanatomical techniques (no loss of reduction 70% vs 73%, subluxation 24% vs 21% and dislocation 6% vs 6%, respectively). The mean methodological quality was 9 out of 16 for noncomparative studies and 17 out of 24 for comparative studies.
Conclusion
It is still not possible to conclude on which technique provides better outcomes for reconstruction of the AC joint in chronic instability patients. Nevertheless, both anatomical and nonanatomical techniques show satisfactory results, with a low rate of failures and re-operations.