High Variability of the Definition of Recurrent Glenohumeral Instability: An Analysis of the Current Literature by a Systematic Review

Abstract

Purpose: To determine the definitions for recurrence used in the literature, assess the consensus in using these definitions, and determine the impact of these definitions on recurrence rates. Methods: A literature search was performed in PubMed and EMBASE including studies from 2000 to 2020 reporting on recurrence rates after anterior arthroscopic shoulder instability surgery. Dislocation, apprehension, subluxation and recurrence rates were compared. Results: Ninety-one studies were included. In 68% of the eligible studies, recurrence rates are not well defined. Thirty (33%) studies did not report on dislocations, 45 (49%) did not report on subluxations, and 58 (64%) did not report on apprehension. Seventeen different definitions for recurrence of instability, 4 definitions of dislocations, and 8 definitions of subluxation were used. Conclusion: Recurrence rates are poorly specified and likely underreported in the literature, hampering comparison with results of other studies. This highlights the need for a consensus on definition of recurrence across shoulder instability studies. We recommend not using the definition recurrence of instability anymore. We endorse defining dislocations as a radiographically confirmed dislocation or a dislocation that is manually reduced, subluxations as the feeling of a dislocation that can be (spontaneously) reduced without the need for a radiographically confirmed dislocation, and a positive apprehension sign as fear of imminent dislocation when placing the arm in abduction and external rotation during physical examination. Reporting on the events resulting in a dislocation or subluxation aids in making an estimation of the severity of instability. Level of Evidence: Level IV, systematic review.

Clinical Outcomes of Arthroscopic Bony Bankart Repair for Anterior Instability of the Shoulder: A Systematic Review

“…In terms of functional outcomes, we suggest the use of the Rowe score because it is currently the most commonly used clinical outcome measure in both arthroscopic bony Bankart repair and shoulder instability research as a whole. 33 Further, we agree with the recommendation by Alkaduhimi et al 3 that recurrence should be categorized into dislocation, subluxation, and apprehension. In addition to investigating the clinical outcomes of bony Bankart repair, future studies should explore other key questions including differences in clinical outcomes between specific arthroscopic techniques and glenoid bone loss thresholds for arthroscopic surgery.…”

“…Specifically, they recommended that the term recurrence should no longer be used and that this condition should be instead separated into the distinct categories of dislocation, subluxation, and apprehension. 3 Last, the current study highlights that the definition of return to sports in shoulder instability is too broad. Return to sports depends on several factors, including the type of sport (recreational, overhead, collision, contact), the level of competition, and compliance with rehabilitation protocols.…”

“…This critical difference in definition undoubtedly contributes to the wide discrepancy in the rates of recurrence after arthroscopic bony Bankart repair. Alkaduhimi et al 3 recently highlighted the need for a consensus definition of recurrence with regard to glenohumeral instability. Specifically, they recommended that the term recurrence should no longer be used and that this condition should be instead separated into the distinct categories of dislocation, subluxation, and apprehension.…”

Development and training of a machine learning algorithm to identify patients at risk for recurrence following an arthroscopic Bankart repair (CLEARER): protocol for a retrospective, multicentre, cohort study

“…Shoulder instability is defined as either a complete dislocation or subluxation. 20 Exclusion criteria include patients who underwent previous stabilisation procedures or other surgical procedures to the ipsilateral shoulder than arthroscopic Bankart repair and patients with posterior, multidirectional or voluntary habitual instability.…”

“…The inclusion criteria are patients treated with arthroscopic Bankart repair without remplissage for traumatic anterior shoulder instability with a minimum of 2-year follow-up. Shoulder instability is defined as either a complete dislocation or subluxation 20. Exclusion criteria include patients who underwent previous stabilisation procedures or other surgical procedures to the ipsilateral shoulder than arthroscopic Bankart repair and patients with posterior, multidirectional or voluntary habitual instability.…”