Long-term subscapularis strength assessment after Bristow-Latarjet procedure: isometric study

• Published in: Journal of shoulder and elbow surgery 2012, Vol.21 (1), p.42-47
• Main Authors: Paladini, Paolo, MD, Merolla, Giovanni, MD, De Santis, Elisa, MS, Campi, Fabrizio, MD, Porcellini, Giuseppe, MD
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Diseases of the osteoarticular system; Female; Follow-Up Studies; Humans; Isometric Contraction - physiology; isometric test; Joint Instability - physiopathology; Joint Instability - surgery; Male; Medical sciences; Middle Aged; Muscle Strength - physiology; Open shoulder stabilization; Orthopedics; Postoperative Period; Retrospective Studies; Rotator Cuff - physiopathology; Rotator Cuff - surgery; shoulder instability; Shoulder Joint - physiopathology; Shoulder Joint - surgery; tendon repair; Tenotomy - methods; Time Factors; Treatment Outcome
• ISSN: 1058-2746; 1532-6500
• DOI: 10.1016/j.jse.2011.03.027

Background The subscapularis is the strongest rotator cuff muscle. Bristow-Latarjet procedure may impair subscapularis function. The aim of the study is to describe the difference in isometric subscapularis (SSC) strength after L-shape tenotomy versus muscle split in patients who underwent to Bristow-Latarjet procedure. Materials and methods From 2000 to 2006, we enrolled 376 patients for Bristow-Latarjet procedures. We identified 2 groups according to the subscapularis approach. Group A included 264 subjects with subscapularis L shape tenotomy; group B included 112 subjects with subscapularis muscle split. The subscapularis function was assessed with lift-off and belly-press tests. Isometric strength of rotator cuff muscle was assessed at an average follow-up of 45 months in group A and 42 months in group B, recording the maximum isometric peak torque (PT) (N), maximum isometric couple (Nm), relative strength index (N/Kg), strength, couple and external/internal rotator ratio. Constant and Rowe were used as scores. Results Subscapularis assessment in the overall population showed 33 cases (8.8%) with a positive Lift-off test and 30 cases (8%) with a positive belly-press test. Rowe and Constant scores increased in both groups ( P < .01). The mean PT in group A was lower of 24,8 Nw than group B ( P < .01); similarly, the max PT values of group A were lower of 26.1 Nw than group B ( P < .01). Conclusion L-shaped tenotomy in Bristow-Latarjet procedure has a weakening effect on the subscapularis and for these reasons we strongly recommend the muscle split approach for an optimal subscapularis function recovery.