Variability in Outcome Reporting for Operatively Managed Anterior Glenohumeral Instability: A Systematic Review

Purpose: The purpose of this study was to quantify the degree of variability in outcomes assessed after surgery for anterior shoulder instability in recent high-impact literature.

Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, an extensive review of the literature during a 5-year period from January 2011 through December 2015 was performed across 6 orthopaedic journals with high impact factors to identify all studies investigating outcomes after anterior shoulder instability. Studies reporting clinical outcomes for patients with anterior glenohumeral instability after surgical treatment with at least 1-year follow-up were included. Several metrics were collected from each manuscript: (1) range of motion (ROM), (2) quantitative strength, (3) physical examination testing, (4) imaging, (5) patient-reported outcomes (PROs), (6) complications (including recurrent instability), (7) patient satisfaction, and (8) return to preinjury level of activity or sport. Variability in outcome measures was then qualitatively assessed.

Results: Sixty-eight studies were included for final analysis ranging from Level I to IV evidence. Fifty-nine percent reported ROM, and 18% measured strength. Other clinical exam maneuvers were assessed in 44%, with 40% assessing apprehension. Imaging was used in 62%, including X-rays, magnetic resonance imaging, and computed tomography scans. On average, 2.25 PROs were assessed. In total, 28 different PROs were used to assess outcomes. The 3 most commonly reported PROs were the Rowe scale at 46%, the Western Ontario Shoulder Instability Index at 31%, and the Constant Shoulder Score at 26%. Twenty-five percent included patient satisfaction in their assessment of outcomes. Recurrence was assessed by 59%, and return to preinjury level of activity was reported by 37% of the studies.

Conclusions: There is substantial variability in outcome reporting for high-impact anterior shoulder instability literature with 28 different outcome tools used, making it difficult to compare outcomes between studies. Agreeing upon a uniform measure to assess outcomes would allow for clearer interpretation of the literature as well as the potential to draw conclusions from pooled data.

Level of evidence: Level IV, systematic review of Level I to IV studies.