structural failure after acromioclavicular joint reconstruction: factors affecting clinical outcomes

Objectives: management of acromioclavicular (ac) joint injuries remains controversial regarding ideal surgical indications and technique. while loss of reduction following ac reconstruction is common, its relationship to clinical outcomes is uncertain. the purpose of this study was to evaluate outcomes and potential predictors of suboptimal results in patients with structural failure following ac reconstruction. methods: patients with structural failure following ac reconstruction from 2013-2019 were identified, defined as 50% loss of coronal ac joint reduction between immediate and final postoperative radiographs. failures were categorized by degree of displacement and mechanism, which included traumatic reinjury versus spontaneous subsidence of ac reduction. suboptimal clinical outcomes were defined as undergoing reoperation or postoperative american shoulder and elbow surgeons (ases) score less than 80. bivariate analyses were performed to identify risk factors for suboptimal clinical results and compare outcomes between operative versus nonoperative management of structural failure.results: twenty-nine patients were evaluated with mean follow-up of 7.4 years (range 4.0-10.5 years). 21% underwent revision surgery (n = 6) and 79% were treated nonoperatively (n = 23). mean postoperative ases, numerical rating scale (nrs), and single assessment numeric evaluation (sane) scores at final follow-up were 82 +/- 20 (range 33-100), 1.6 +/- 2.2 (range 0-7), and 82 +/- 20 (range 22-100) respectively. 41% of the total cohort (n = 12) had a suboptimal clinical result. on bivariate analysis, structural failure following acute reinjury was associated with suboptimal clinical outcomes (50% vs 6%, p = 0.011) and a higher likelihood of reoperation (67% vs 13%, p = 0.018).conclusion: structural failures of ac reconstruction following an acute injury are more likely to experience suboptimal clinical outcomes and undergo reoperation compared to spontaneous loss of reduction. larger analyses are warranted to determine if there are additional factors which may affect outcomes and guide management in these clinical scenarios.        level of evidence: iv