Background: The standard Weaver-Dunn reconstruction of the acromioclavicular (AC) joint does not provide adequate superoinferior or anteroposterior stability. Augmentation methods such as tape cerclage have been described. A new method of augmentation with the Arthrex TightRope is available.
Hypothesis: A Weaver-Dunn reconstruction augmented with the TightRope will provide superior superoinferior and anteroposterior stability to the AC joint as compared with a Weaver-Dunn reconstruction augmented with Mersilene fiber tape cerclage.
Study design: Controlled laboratory study.
Methods: Six matched pairs of cadaveric shoulders underwent Weaver-Dunn AC joint reconstructions and were randomly assigned to receive either the TightRope device or tape cerclage augmentation. Translation in 2 planes was measured in the intact state under load and after 1 load cycle and 2000 load cycles.
Results: TightRope-augmented repair showed less superoinferior translation (mean +/- standard error) than cerclage-augmented repair in initially repaired (1.6 +/- 0.1 mm vs 5.0 +/- 1.1 mm, P = 0.03) and cyclically loaded (2.1 +/- 0.1 mm vs 5.8 +/- 1.2 mm, P = 0.02) conditions. TightRope repairs were stiffer than the native ligaments in the superoinferior plane. Less anteroposterior translation was observed with TightRope versus cerclage augmentation (initially repaired, 6.8 +/- 0.4 mm vs 18.8 +/- 2.6 mm, P < 0.001; cycled, 15.0 +/- 1.4 mm vs 28.3 +/- 2.7 mm, P = 0.01), but neither method maintained normal anteroposterior laxity after 1500 cycles compared with the intact state.
Conclusion: Superoinferior and anteroposterior translation with TightRope augmentation was lower than with tape cerclage.
Clinical relevance: TightRope augmentation of a Weaver-Dunn procedure could provide increased protection for AC joint reconstruction, allowing for earlier mobilization and more aggressive early rehabilitation. The potential clinical effect of additional tightening in the superoinferior direction beyond that of the native joint remains an issue for further study.