Infraspinatus function impairment after arthroscopic Bankart repair with Hill Sachs remplissage. Isokinetic, functional, and radiographic analysis

Abstract

Purpose: Arthroscopic Bankart repair with Hill Sachs remplissage (BHSR) is an option for anterior shoulder instability with humeral defect. Our hypothesis was that infraspinatus capsulo-tenodesis is an effective solution, with good clinical results and no consequences on shoulder strength and ranges of motion.

Methods: We performed a retrospective case-control study involving 22 patients operated with arthroscopic BHSR. We compared isokinetic evaluation of both shoulders using a dynanometer in concentric, eccentric force and endurance. Ranges of motion were measured using a goniometer and compared to the contralateral unaffected side. Functional assessment included Constant, Rowe, Walch and Duplay and WOSI scores. Healing and fatty degeneration were analyzed with magnetic resonance imaging.

Results: At mean 37.2 months follow-up, 21 patients (95.4%) were satisfied or very satisfied with the intervention. Range of motion in external rotation of the affected side decreased by 10.8° in adduction and 6° at 90° of abduction (p<0.05). Deficit in external rotation strength of the affected side greater than 15% was found in all isokinetic tests (p<0.05). Walch and Duplay, Rowe, WOSI and adjusted Constant average scores were respectively 71.05±14.1 (40-90), 67.63±19.7 (15-100), 34.6%±19.9 (8.43-76.23) and 69.8±13.57 (36.7-101). Postoperative MRI showed good capsulo-tenodesis healing without infraspinatus muscle fatty degeneration.

Conclusion: Arthroscopic BHSR provides satisfactory functional outcomes but significant infraspinatus functional impairments in both strength and ranges of motion in external rotation.

Level of evidence: III; case-control study.

Keywords: Capsulo-tenodesis; Hill Sachs lesion; Infraspinatus; Instability; Isokinetic; MRI; Remplissage; Strength.