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.

Key Words:  Bankart lesion , External rotation , ALPSA lesion