Lower Trapezius Transfer vs Bridging Reconstruction

Research Plan: A total of 60 patients will be enrolled in the study. In the pre-operative period, there will be no additional time requirements for the patient, except for the informed consent process for the study. Routine radiographs including an AP and Y view of the shoulder as well as a pre-operative MRI are obtained for all patients undergoing rotator cuff surgery.

The patients will complete a structured clinical examination conducted by a sports medicine fellowship trained orthopaedic consultant. The examination will consist of range of motion testing by goniometer, range of motion testing evaluated by one's reach envelope, as well as strength testing by hand dynamometer. The patient will also complete the Western Ontario Rotator Cuff Index (WORC) questionnaire.

Randomization: Randomization will be done with a computer random number generator. Treatment conditions will be inserted in ordered opaque envelopes. Two groups (bridging reconstruction, and lower trapezius transfer) will be selected with 30 subjects each group.

Surgical Procedures: Wong et al. (2021) described the surgical procedure for patients in the "Bridging" group. The bursa will be debrided thoroughly, and rotator cuff edges will be shaved down to stable tissue. Following this, an acellular human dermal patch will be rehydrated in saline solution for 15 minutes. The patch is stretched to remove the manufacturing surface irregularities. The patch is then sewn in place with braided polyester suture material. Multiple sutures, approximately 5 to 10 mm apart from one another will be used. The medial sutures are placed into the remnants of supraspinatus and infraspinatus tendons. The patch is then attached to the greater tuberosity in a double row configuration.

The lower trapezius transfer will be performed as described by Wagner et. al. (2018). Patients will be placed in beach chair position, with the ipsilateral half of the back uncovered for surgical access. A 5-cm vertical skin incision will be made 1 cm from the medial border of scapula by the upper and lower edge of the lower trapezius tendon. The fat area at the inferior edge of the lower trapezius tendon will be identified, and the lower trapezius tendon will be completely released from spine of scapula and medially through opening of the superficial fascia. Two sutures in a Krakow configuration will be placed in the lower trapezius tendon. 2 sutures of different colors will be placed in the thick part of the allograft in a Krakow configuration. Designated ventral and dorsal aspects of the allograft will be marked. The infraspinatus fascia will be opened at the level of the medial incision. The sutures in the thick part of the allograft are then clamped to bring the graft intra-articular. Each of the Krakow sutures placed in the thick end of the allograft are passed to each of the 2 loadable suture anchors to attach the most distal part of the allograft, fixating the graft.

Postoperative protocol: The shoulder will be immobilized in a sling for one week postoperatively, and only passive forward flexion and external rotation will be allowed for eight weeks. The patient then progresses to active shoulder motion. Strengthening will begin at twelve weeks postoperatively. The patient will follow-up with the attending surgeon (IW) at 2 weeks post-operatively for a wound check. Then further clinical follow-up appointments will be at 6 weeks, 3 months, 6 months, 12 and 24 months, as per current clinical practice.

At the 6, 12, and 24 month visits the patient will again undergo the structured clinical examination conducted by a sports medicine fellowship trained orthopaedic consultant who is blinded to the patients' treatment group. The patient will also complete the WORC questionnaire at these follow-up appointments. Radiographs will be taken also to obtain the postoperative measurements. MRI will be done to assess healing at 12 months.

Analysis of Data: The data collected will be analyzed through SPSS version 24. Two-tailed independent t-tests will be performed for the WORC, acromiohumeral distance, range of motion, and strength measures comparing the two groups at most recent postoperative measurement. Repeated-measures ANOVA will be used to assess differences in WORC scores, range of motion and strength within each group between time points.

Inclusion criteria

• magnetic resonance imaging (MRI) proven diagnosis of a massive rotator cuff tear
• tear size >5cm
• two-tendon, irreparable tear
• competent adult (>18 years of age)
• <50% muscle atrophy.

Exclusion criteria

• irreparable subscapular tear
• glenohumeral osteoarthritis
• WORC score > 70
• uncontrolled diabetes (Hgb A1C >7%)
• pregnancy
• presence of local or systemic infection
• inability to cooperate with and/or comprehend post-operative instructions
• cancer
• paralysis of the shoulder
• contracture of the shoulder
• inability to provide informed consent