Utility of the Instability Severity Index Score in Predicting Failure After Arthroscopic Anterior Stabilization of the Shoulder

Abstract

This is the first completely independent study to confirm that the ISIS is a useful preoperative tool. It is recommended that surgeons consider alternative forms of stabilization if the ISIS is ≥4.

Arthroscopic Bankart Repair for the Management of Anterior Shoulder Instability: Indications and Outcomes

“…Rouleau et al assessed the multicenter reliability of the ISS and found that it was very reliable, with an interclass coefficient of 0.933. Despite this, it is important to note that it did not correlate with quality of life questionnaires in patients [12].…”

“…Phadnis et al reported on the utility of the ISIS in predicting failure of arthroscopic Bankart repair. Out of 141 patients, 19 (13.5%) experienced recurrence, with their mean ISI score being significantly higher than those who did not recur (5.1 versus 1.7) [12]. GBL carried the highest risk of failure (70%).…”

“…GBL carried the highest risk of failure (70%). Also, patients with an ISIS ≥ 4 had a 70% change of failures as opposed to a 4% risk of recurrence with a score < 4 [12]. Rouleau et al assessed the multicenter reliability of the ISS and found that it was very reliable, with an interclass coefficient of 0.933.…”

The Epidemiology and Natural History of Anterior Shoulder Instability

“…The authors found that if a patient had a score > 6, they had a 70% chance of recurrent dislocation after a soft tissue repair and advocated a bony stability surgery. This was later studied by Phadnis et al who found in their series that a score of ≥ 4 was associated with a 70% risk of failure [88]. These studies demonstrate the high rate of recurrent instability even following surgery in young, competitive athletes who have glenoid or humeral bone loss, and thus, these patients should not be routinely treated with nonoperative management.…”

Review of Arciero's article (1994) on arthroscopic Bankart repair versus non-operative treatment for acute, initial anterior shoulder dislocations: does the same hold true in 2016?

“…In their previous study,60 the majority of the patients who failed initial surgical stabilisation underwent revision with a Latarjet procedure, which the authors now recommend for high-risk patients who present with ISIS >6 instead of arthroscopic Bankart repair for index surgery. In a case–control study, ISIS was retrospectively assessed on a series of patients who either had success or failure of arthroscopic stabilisation to calculate its sensitivity, specificity and positive and negative predictive values 62. The results demonstrated a 70% rate of failure when the ISIS was ≥4.…”