Technical Guide and Tips to Arthroscopic Trans-scapular Transfer of Lower Trapezius for Irreparable Subscapularis Tears

Abstract

The efficacy of tendon transfers in the treatment of irreparable subscapularis tears has been inconsistent, with frequently unsatisfactory outcomes. We describe a technique for transfer of the lower trapezius tendon to the lesser tuberosity using an Achilles tendon allograft through a trans-scapular route after a scapular osteotomy. The surgical procedure begins with the preparation of the lower trapezius tendon via an open posterior incision. After splitting the infraspinatus muscle, the osteotomy of the scapular body is performed inferior to the scapular spine and medial to the glenoid vault. Then, the arthroscopic dissection of the anterior space of the glenohumeral joint and subscapular fossa is performed. The axillary and radial nerves are visualized and protected. The anterior dissection is completed by debridement of the subscapularis remnant as well as the subscapular fossa. A shuttle relay is placed, and the allograft is shuttled from the posterior scapula to the anterior compartment of the glenohumeral joint following the subscapular fossa. After debridement of the lesser tuberosity, the graft is fixed with 2 lateral anchors and 1 medial anchor. The shoulder is immobilized in internal rotation for a period of 6 weeks, after which physiotherapy can be started.

Fig 1

Portals for trans-scapular transfer of the lower trapezius for subscapularis insufficiency shown on a right shoulder in the beach-chair position. (A, posterior soft spot; D, anterolateral portal; E, anterolateral portal; J, lateral to the coracoid.) (Image source: Lafosse et al.¹⁷).

Fig 2

Technical steps of a trans-scapular transfer of the lower trapezius to the lesser tuberosity. The surgery is performed on a left shoulder in the beach-chair position. (A) Horizontal incision 1 cm inferior to the medial part of the scapular spine. (B) Preparation of the lower trapezius tendon. (C) Scapular osteotomy inferior to the scapular spine and medial to the glenoid vault. (D) Insertion of a shuttle relay with a link suture. (ISP, infraspinatus; LT, lower trapezius; Sc, scapular body.)

Fig 3

Technical steps of a trans-scapular transfer of the lower trapezius for irreparable subscapularis tear. The surgery is performed on a left shoulder in the beach-chair position. (A) Dissection of the anterior space (posterior soft spot viewing portal). (B) Further dissection of the anterior space with the arthroscope switched to the anterolateral portal with visualization of the axillary nerve (ax). (C) Debridement of the subscapularis remnant and the anterior glenoid vault (anterolateral viewing portal). (D) Passage of the link suture through the glenoid osteotomy (anterolateral viewing portal). (ax, axillary nerve; Co, coracoid; H, humeral head, L, labrum; Sc, scapula; SSC-R, remnant of subscapularis tendon.)

Fig 4

Technical steps of a trans-scapular transfer of the lower trapezius to the lesser tuberosity. The surgery is performed on a left shoulder in the beach-chair position. (A) Passage of the Achilles tendon allograft from posterior to anterior. (B) Arthroscopic debridement of the lesser tuberosity (anterolateral viewing portal). (C) Fixation of the graft superior to the lesser tuberosity with medial and lateral knotless suture anchors (anterolateral viewing portal). (D) Posterior fixation of the graft with the lower trapezius tendon. (F, footprint of subscapularis tendon; Gr, graft.)