Presentation
Status post-arthroscopically-assisted lower trapezius tendon transfer with Achilles tendon allograft, performed 10 months ago. The patient now presents with increased pain and difficulty with an active forward elevation of the arm above 90 degrees.
Patient Data
CT of the right shoulder shows severe atrophy of the infraspinatus muscle. There is a thick, linear, hyperdense structure overlying the atrophied infraspinatus muscle, which represents the Achilles tendon allograft. This is at the level of the inferior border of the scapular spine. Medially, this graft is contiguous with the native trapezius tendon. Laterally, this extends towards the posterior aspect of the humeral head. There are three suture anchors in the region of greater tuberosity. A cortical endobutton in the proximal humeral diaphysis is related to biceps tenodesis. There is superior migration of the humeral head, best seen in the coronal images. Postsurgical changes from subacromial decompression and acromioplasty are also noted.
MR arthrogram of the right shoulder shows a thick linear hypointense structure at the posterior aspect of the shoulder, consistent with an Achilles tendon allograft. The calcaneal side of the Achilles tendon is lateral in this case and does not seem attached to the suture anchors or have greater tuberosity, consistent with graft tear/non-healing with retraction. There are full-thickness tears in the native supraspinatus and infraspinatus tendons. Severe atrophy of the infraspinatus muscle is seen. The teres minor and subscapularis tendons are intact. Biceps tenodesis is noted. Contrast is present in the glenohumeral joint, subacromial subdeltoid bursa, and acromioclavicular joint.
Case Discussion
Lower trapezius transfer with Achilles tendon augmentation is used to treat patients with irreparable posterosuperior rotator cuff tears or for those with shoulder paralysis that impedes external rotation 1. This surgery uses the Achilles tendon to attach the lower trapezius tendon to the greater tuberosity of the humerus.
Promising clinical and radiographic outcomes have been seen for this surgery in functionally irreparable rotator cuff tears 2. Candidacy for this technique requires an intact or reparable subscapularis tendon, no advanced glenohumeral arthritis, and no humeral head femoralization.
This is the first reported case of Achilles tendon graft retraction from a lower trapezius transfer, proven on imaging. In this patient, the cause of lower trapezius transfer graft failure is unknown; there was no history of trauma. The patient is scheduled for right-reverse total shoulder arthroplasty.
Case co-contributor: Jason Lee (Loyola University).
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