Loss of Passive External Rotation at 90° Abduction Is Predictive of a Medially Healed Bankart Lesion

Purpose: This prospective study correlates passive range of external rotation with arthroscopic findings in patients with anterior instability for the purpose of defining criteria that can be used to detect a medially healed Bankart lesion. Methods: External rotation at 90° abduction (ER90) was assessed on examination with the patient under anesthesia in bilateral shoulders of 46 consecutive patients with unidirectional, anterior glenohumeral instability. Arthroscopy was used to identify 22 patients with a detached Bankart lesion (group I) and 24 patients with a medially healed Bankart lesion (group II). Differences in ER90 between symptomatic and asymptomatic shoulders for both groups were compared. The t test and the Wilcoxon rank-sum test measured significance. Results: In group I, mean ER90 in the symptomatic shoulder was 5° greater than in the asymptomatic shoulder; in group II, mean ER90 in the symptomatic shoulder was 7.4° less than in the asymptomatic shoulder (P < .001). Loss of ER90 was highly sensitive (92%) and specific (95%), with a positive predictive value of 96% for detection of a medially healed Bankart lesion. Conclusions: If a loss of 5° or more of ER90 in the affected shoulder is found on examination under anesthesia, one should have a high degree of suspicion for the presence of a medially healed Bankart lesion. Level of Evidence: Level II, development of diagnostic criteria on basis of consecutive patients.