Reverse Total Shoulder Arthroplasty for Treatment of Massive, Irreparable Rotator Cuff Tear

Abstract

Massive tears of the rotator cuff can result in severe functional deficits due to loss of the axial force couple and effective fulcrum that the intact cuff normally provides. For massive, irreparable rotator cuff tears, especially in the setting of early to moderate degenerative changes, reverse total shoulder arthroplasty functions to modify the center of joint rotation, allowing the deltoid and intact components of the cuff to carry out shoulder function more effectively. Our preferred technique uses a standard open deltopectoral shoulder approach with a 3-dimensional glenoid baseplate model and a 135° prosthesis in an onlay configuration to reduce the risk of scapular notching and increase lateralization of the humerus.

Fig 1

Incision. A standard deltopectoral approach is performed in the right shoulder with the patient in the beach-chair position. (A) The incision point is made between the coracoid process and the proximal humeral shaft toward the deltoid insertion. (B) The exposed deltoid is retracted laterally and the conjoint tendon is retracted medially, with care taken to avoid the musculotendinous nerve and underlying brachial plexus.

Fig 2

Subscapularis peel. (A) A lateral subscapularis peel is performed on the right shoulder using needle-tip Bovie electrocautery. (B) A No. 2 Ethibond whipstitch is placed in the top rolled edge of the subscapularis.

Fig 3

Exposure of humeral head. The humeral head is brought out of the right shoulder anteriorly using a 2-point Hohmann retractor (A), and with external rotation, it is brought anteriorly out of the shoulder joint (B).

Fig 4

Humeral head removal. Removal of the humeral head in the right shoulder is performed at 20° to 25° of retroversion using a 135° external cutting guide. (A) After humeral canal reaming, the humeral canal broach is performed using 5-mm then 6-mm broaches with a 20° version guide. (B) The proximal humeral canal will be used later to place the final 6-mm press-fit humeral stem.

Fig 5

Glenoid preparation. A guide pin is placed (A), and the glenoid canal in the right shoulder is reamed with a 7-mm glenoid reamer (B). (C) A sterile 3-dimensionally printed model is used to ensure correct positioning of the glenoid guide pin.

Fig 6

Glenoid baseplate fixation. (A) The baseplate is positioned in the glenoid of the right shoulder with a central 20-mm compression screw for fixation. By use of a drill guide, a 30-mm compression screw is placed superiorly and a 24-mm compression screw is placed inferiorly. (B) A 36-mm glenosphere with +4 offset is placed on the baseplate.

Fig 7

Humeral component fixation. (A) Three suture tape sutures are placed through proximal humeral drill holes in the right shoulder. These will be used to repair the subscapularis after final implant placement and shoulder reduction. A 6-mm press-fit stem and a 36-mm cup with a +6 constrained liner are tested in the humeral shaft. (B) Excellent fixation is noted, with good suction and no inferior translation, and the press-fit stem and the 36-mm cup with the +6 constrained liner are tamped into position.

Fig 8

Subscapularis repair. The 3 suture tape sutures previously placed through the proximal humeral drill holes in the right shoulder are identified (A) and are used to repair the subscapularis (B).