Evaluation of the Instability Severity Index Score and the Western Ontario Shoulder Instability Index as predictors of failure following arthroscopic Bankart repair

Abstract

In this study we evaluated whether the Instability Severity Index Score (ISIS) and the Western Ontario Shoulder Instability Index (WOSI) could detect those patients at risk of failure following arthroscopic Bankart repair. Between April 2008 and June 2010, the ISIS and WOSI were recorded pre-operatively in 110 patients (87 male, 79%) with a mean age of 25.1 years (16 to 61) who underwent this procedure for recurrent anterior glenohumeral instability. A telephone interview was performed two-years post-operatively to determine whether patients had experienced a recurrent dislocation and whether they had returned to pre-injury activity levels. In all, six (5%) patients had an ISIS > 6 points (0 to 9). Of 100 (91%) patients available two years post-operatively, six (6%) had a recurrent dislocation, and 28 (28%) did not return to pre-injury activity. No patient who dislocated had an ISIS > 6 (p = 1.0). There was no difference in the mean pre-operative WOSI in those who had a re-dislocation and those who did not (p = 0.99). The pre-operative WOSI was significantly lower (p = 0.02) in those who did not return to pre-injury activity, whereas the ISIS was not associated with return to pre-injury activity (p = 0.13). In conclusion, neither the pre-operative ISIS nor WOSI predicted recurrent dislocation within two years of arthroscopic Bankart repair. Patients with a lower pre-operative WOSI were less likely to return to pre-injury activity.

Editorial Commentary: Which Patients Are Likely to Undergo Redislocation After an Arthroscopic Bankart Repair? Preoperative Instability Severity Index Scoring Over 3 Points—The Game Is Over!

“…Another potential study weakness is the lack of inter-rater and intrarater reliability of the score, specifically for the radiographic portion. We agree with Bouliane et al 8 that improving the radiographic component of the ISI Score would serve to strengthen the score and further enhance its clinical utility. The use of 2-or 3-dimensional imaging provides a more accurate representation of bony lesions and is part of our routine imaging studies in patients with unstable shoulders.…”

“…5 The Instability Severity Index (ISI) Score is a useful tool that has already changed the approach to the treatment of post-traumatic glenohumeral instability in Europe and Canada. [6][7][8][9] At the moment, this scoring system remains poorly known and used in the United States, but it is our opinion that such a tool deserves to be spread among shoulder surgeons. 10 important question for both surgeons and patients.…”

“…6,7,11,12 If the contribution of French authors is momentarily ignored, there remains a paucity of published work from other countries assessing the validity of the ISI Score. [8][9][10] In this issue, the study titled "Is the Instability Severity Index Score a Valid Tool for Predicting Failure After Primary Arthroscopic Stabilization for Anterior Glenohumeral Instability?" by Loppini, Delle Rose, Borroni, Morenghi, Pitino, and Castagna 13 provides the external validity for which the ISI Score has so patiently been waiting.…”

Glenoid Track Instability Management Score: Radiographic Modification of the Instability Severity Index Score

“…Thomazeau et al 4 similarly suggested that an ISIS 4 is ideal for arthroscopic Bankart repair. In contrast, Bouliane et al 5 concluded that ISIS was incapable of predicting recurrent instability in their cohort of 110 patients at 2 years after arthroscopic Bankart repair.…”

“…However, it is not only just the presence of glenohumeral bone loss, but also the interplay between the glenoid and humeral lesions, as suggested by the glenoid track concept, that contribute to recurrent instability. 5,21 According to the glenoid track concept, which has been verified biomechanically and clinically, 19,28 a Hill-Sachs lesion may be characterized as "on-track" or "off-track." 29 An off-track lesion is one with bipolar bone loss that engages between the Hill-Sachs lesion and glenoid rim and increases the risk of recurrent stability if bone loss is not addressed.…”