Do patients with minor shoulder instability have a different outcome from those with recurrent anteroinferior instability?

Purpose: Minor or anterosuperior shoulder instability (MSI) is a relatively new concept with other characteristics than recurrent anteroinferior instability (TUBS). MSI includes patients without history of dislocation, with non-specific clinical symptoms and signs but with indications of laxity of (SGHL)/MGHL with isolated injury of (SGHL)/MGHL seen during arthroscopy. TUBS patients typically present with recurrent anteroinferior instability with at least labral injury of the anterior band of the IGHL. In this study, we focus on the postoperative (rehabilitation) course. Our hypothesis is that its duration is prolonged in patients with MSI when compared to those with TUBS. Methods: Thirty-five patients with isolated anterosuperior capsuloligamentous lesions identified during arthroscopic surgery (group I-MSI) and 65 with at least an anteroinferior capsuloligamentous lesion (group II-TUBS) completed a survey that included a questionnaire enquiring into relief of pain and return to activity, the Oxford Shoulder Instability Score (OSIS) and the Western Ontario Shoulder Instability index (WOSI). Final follow-up occurred at a mean of 76 months postoperatively. Results: Pain at night, at rest and during overhead activities disappeared later in group I than in group II (respectively, p = 0.03; 0.01; 0.01). Patients with MSI returned later to professional activities (p = 0.02) and to the same sport (p = 0.01). In addition, they had worse outcome as measured by OSIS (p = 0.01) and WOSI (p = 0.07). Conclusion: Patients with MSI have poorer prospects regarding time to relief of pain, return to work and sports and outcome scores compared to patients with TUBS.