Arthroscopic biceps superior capsular reconstruction for irreparable massive rotator cuff tear with posterior dislocation of the long head of the biceps tendon and irreducible anterior glenohumeral subluxation: A case report and literature review.

INTRODUCTION: Irreducible anterior glenohumeral subluxation secondary to posterior dislocation of the long head of the biceps tendon (LHBT) and massive rotator cuff tears (MRCTs) is a rare, complex clinical condition that poses significant diagnostic and therapeutic challenges. This case report emphasizes the successful application of arthroscopic treatment, specifically the superior capsular reconstruction (BSCR), as well as the indispensable role of MRI in early and accurate diagnosis. PRESENTATION OF CASE: A 61-year-old female presented to the clinic following a motor vehicle accident with complaints of persistent left shoulder pain, restricted range of motion (ROM), and functional impairment. Initial radiographs revealed anterior glenohumeral subluxation, which was further confirmed by MRI, demonstrating posterior dislocation of the LHBT and MRCTs. Despite unsuccessful attempts at closed reduction, the patient underwent arthroscopic repositioning of the LHBT, arthroscopic repair of the rotator cuff and BSCR. Postoperatively, the patient underwent mobilization and rehabilitation, achieving stable joint reduction, tendon healing, and excellent functional outcomes within six months. DISCUSSION: Posterior dislocation of the LHBT constitutes an uncommon yet clinically significant cause of irreducible glenohumeral subluxation. Clinicians should consider the potential for posterior LHBT dislocation even when post-injury imaging does not reveal complete shoulder dislocation. MRI plays a critical role in ensuring accurate and timely diagnosis through early evaluation. Current guidelines for managing the combined injuries of anterior glenohumeral subluxation, posterior LHBT dislocation, and MRCTs remain poorly defined. Early diagnosis and timely surgical intervention are generally recommended for glenohumeral joint reduction and rotator cuff repair. We have successfully implemented an arthroscopic approach for glenohumeral reduction, incorporating the BSCR for irreparable MRCTs, with promising efficacy. Early surgical intervention and personalized treatment strategies are recommended for managing such complex injuries. CONCLUSION: This case exemplifies the diagnostic value of MRI and the successful implementation of arthroscopy in detecting and managing posterior LHBT dislocation. It also endorses BSCR as an effective alternative for irreparable MRCTs, attributing to its biomechanical benefits and the prevention of donor-site morbidity.