Shoulder biomechanics in normal and selected pathological conditions

The stability of the glenohumeral joint depends on soft tissue stabilizers, bone morphology and dynamic stabilizers such as the rotator cuff and long head of the biceps tendon. Shoulder stabilization techniques include anatomic procedures such as repair of the labrum or restoration of bone loss, but also non-anatomic options such as remplissage or tendon transfers.Rotator cuff repair should restore the cuff anatomy, reattach the rotator cable and respect the coracoacromial arch whenever possible. Tendon transfer, superior capsular reconstruction or balloon implantation have been proposed for irreparable lesions.Shoulder rehabilitation should focus on restoring balanced glenohumeral and scapular force couples in order to avoid an upward migration of the humeral head and secondary cuff impingement. The primary goal of cuff repair is to be as anatomic as possible and to create a biomechanically favourable environment for tendon healing

Evaluation of the subscapularis split created with passive rotation during arthroscopic dynamic anterior stabilization (DAS): A cadaveric study.

Abstract Introduction The purpose of the present study was to analyze the ability to create a subscapularis split by passive rotation of the arm during dynamic anterior stabilization (DAS) and to analyze the new geometry of the long head of the biceps LHB. Hypothesis The hypothesis was that this passive simple technique can create subscapularis split without additional dissection giving rise to new position of LHB with a new stabilization function. Material and methods A technique of subscapularis split using the LHB was used in 12 fresh-frozen human cadaveric shoulders. A subscapularis split was created by passive rotation of the arm after the LHB is shuttled into the joint during DAS. The length of the subscapularis split, post-DAS position and length of the LHB, and the angulation of the LHB relative to bicipital groove were measured after DAS and if this new geometry can give a new dynamic effect on subscapularis muscle. Results The mean length of the subscapular split after maximal rotation was 20.4 ± 6.0 mm (range: 10–32 mm). The mean elongation of the LHB was 0.6 ± 1.4 mm (range: −1 to +3 mm). The final angle of the LHB relative to the bicipital groove was 45 ± 5 degrees (range: 41 to 55 degrees). Discussion There is no need to create a distinct split prior to DAS. Additionally, DAS maintains the length-tension relationship of the LHB. The post-procedure medial angulation of the LHB relative to the bicipital groove may provide a lowering of the subscapularis, helping explain the anterior reinforcement of this technique. Level of evidence Basic science study, cadaver study

Relationship between subscapularis tears and injuries to the biceps pulley

The purpose of this study was to analyse the relationship between long head of the biceps brachii (LHBT) lesions and subscapularis tears. The hypothesis was that a bicipital pulley might remain intact, even in the case of a subscapularis tear

Arthroscopic glenohumeral arthrodesis with o-arm navigation

Glenohumeral arthrodesis is an end-stage salvage operation that has traditionally been performed in an open fashion. In recent years an arthroscopic approach has been described. The purpose of this report was to present an arthroscopic glenohumeral arthrodesis technique with the assistance of O-arm-based navigation. An illustrative case example is presented. This technique allows not only a minimally invasive glenohumeral arthrodesis but also precise screw fixation by navigation, which may be particularly useful in cases of limited bone stock and/or bony deformity

Massive rotator cuff tears: definition and treatment

The aim of this review is to summarise tear pattern classification and management options for massive rotator cuff tears (MRCT), as well as to propose a treatment paradigm for patients with a MRCT

Midterm outcome of arthroscopic revision repair of massive and nonmassive rotator cuff tears

The purpose of this study was to evaluate the midterm functional outcome of arthroscopic revision rotator cuff repair and compare the outcomes of nonmassive and massive rotator cuff tears

Arthroscopic management of subscapularis tears

Tears of the subscapularis were previously believed to be rare, but are now recognized to be very common. As maintenance of the subscapularis footprint is integral to normal biomechanical function of the shoulder it is important for the shoulder surgeon to be adept at recognizing and treating these tears. A combination of physical examination tests can be used to determine both the presence and size of a subscapularis tear. Compared with posterosuperior rotator cuff tears, magnetic resonance imaging detection of subscapularis is less reliable and therefore requires a high index of suspicion. Arthroscopic repair of the subscapularis presents unique challenges but can be safely and successfully performed with careful attention to detail. The results of arthroscopic subscapularis repair are encouraging at intermediate follow-up and comparable with or better than that reported with open repair

Arthroscopic Recognition and Repair of the Torn Subscapularis Tendon

Although the subscapularis has historically received less attention than posterosuperior rotator cuff tears, repair of a torn subscapularis tendon is critically important to restoring anatomy and achieving the best functional outcome possible. Arthroscopic repair begins with proper recognition of the tear. A systematic approach can then be used to arthroscopically repair all types of subscapularis tendon tears, from partial tears to full-thickness tears, as well as those which are retracted and have adhesions medially. Subscapularis footprint restoration can be accomplished with a variety of repair techniques that must be matched to the extent of the tear and mobility of the tendon