Anterior Rotator Interval Lesion (ARIL), its association with glenoid labrum pathology in patients with anterior shoulder pain and surgical outcome of Arthroscopic Rotator Interval Closure (ARIC).

Background: Anterior rotator interval lesions (ARIL) have been associated with shoulder instability. However, a paucity of data exists on its association with labrum pathology as a source for persistent anterior shoulder pain. This study primarily aims to describe pathoanatomy of ARIL and the parameters we used that aid in the diagnosis of ARIL. Secondly, the objective is to describe and report the prevalence of ARIL in combination with labrum injuries presenting as anterior shoulder pain with mild or no instability. Lastly, we intend to present a cohort of patients with combined labrum injury and ARIL and report on the clinical results after labrum repair with Arthroscopic Rotator Interval Closure (ARIC).

Methods: Consecutive patients at a single center in United States treated for labrum tears were included by retrospective chart-review. Patients presenting with anterior shoulder pain with mild or no instability were included. Patients with recurrent dislocations, moderate to severe instability and those with bony lesions were excluded. Besides history and physical examination, Magnetic Resonance Arthrography (MRA) was used to aid the diagnosis. Labrum tears with ARIL were treated with an additional ARIC procedure along with arthroscopic labrum repair.

Results: Out of two hundred fourty patients with a labrum tear, 114 had associated ARIL. The prevalence of ARIL ranged from 71 % with reverse Bankart tears to 46 % with anterior Bankart and 36 % in Type II SLAP tears. The success rate after labrum tear repair with ARIC performed in patients with ARIL with labrum pathology was 94.7 % at a 2-year follow-up in terms of relief from anterior shoulder pain.

Conclusion: Almost half (47.5 %) of our patients presented with anterior shoulder pain with labrum tears were associated with ARIL. We recommend keeping a high index of suspicion for ARIL in labrum injuries presenting mainly with anterior shoulder pain for better treatment planning.

Level Of Evidence: Level IV (Retrospective case series without a comparision group).