PurposeArthroscopic 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. MethodsWe 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. ResultsAt 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. ConclusionArthroscopic BHSR provides satisfactory functional outcomes but significant infraspinatus functional impairments in both strength and ranges of motion in external rotation. Level of evidenceIII; case-control study.