Background: The volume of anatomic total shoulder arthroplasty has been increasing in recent years. The deltopectoral approach necessitates detaching and subsequent repairing of the subscapularis tendon. Failure of the tendon to heal can lead to pain, compromised function, and patient dissatisfaction. Our aim is to present a review article regarding current thinking on the problem of a diagnostic algorithm and therapeutic guidelines for subscapularis failure following anatomic TSA.
Materials and Methods: Searches were completed in July 2018 using a series of NOT phrases to match certain exclusion criteria in PubMed.
Results: A total of 23 relevant studies were included in the analysis. Only three of the seven studies linked physical examination results to evidence of post-operative subscapularis rupture. Eleven of the eighteen patients with subscapularis tears obtained ultrasonography confirmation, whereas the remaining patients had revision surgery confirmation. The decrease in internal rotation strength and the lift-off test were the most regularly performed tests. The former was shown to be positive in all fourteen patients from two trials, whereas the latter was found to be positive in eight of fourteen. Five studies on therapy in different situations were proposed, but there was no head-to-head comparison of treatment outcomes.
Conclusion: The most common cause of anterior instability in prosthetic shoulder is subscapularis insufficiency. Physical
examination and radiological studies may not provide a conclusive diagnosis. Patients who present with pain, weakness, or instability require surgical treatment, which varies based on their age, tendon reparability, and component position.

Keywords: Subscapularis tear; Subscapularis dysfunction; Subscapularis tenotomy; Lesser tuberosity osteotomy; Total shoulder replacement