Arthroscopically Assisted Lower Trapezius Transfer Using Peroneus Longus Autograft for Irreparable Posterosuperior Rotator Cuff Tears.

Abstract

Background: Massive retracted rotator cuff tears are disabling in physically active patients. In patients with persistent pain in whom nonoperative treatment has failed, multiple surgical treatment options are available. Lower trapezius tendon transfer is a promising surgical procedure that can decrease pain, improve external rotation strength, and recreate more normal glenohumeral kinematics. In the present video article, we describe the surgical technique for successful arthroscopic ("scopy")-assisted lower trapezius transfer (SALTT) with use of an easily accessible peroneus longus autograft.

Description: The patient is positioned in a beach-chair position with the ipsilateral half of the posterior shoulder girdle included in the draping for surgical access. Joint was viewed through the standard posterior and posterolateral portals, while anterolateral and anterosuperior portals were utilized as the working portals. Subacromial and superior capsular adhesions are released, and a partial cuff repair is performed. A 3 to 4-cm vertical incision is made along the scapular spine. The superior and inferior borders of the lower trapezius are delineated and completely detached from where they insert at the scapular spine. A 3-cm vertical incision is made at the posterior border of the lateral malleolus. The fascia is incised. The peroneus longus is identified and detached with the foot in maximum dorsiflexion and eversion and is harvested with use of a closed tendon stripper. Whip stiches are placed at 1 end of the autograft. With use of a large grasping clamp, starting from the anterolateral portal and aiming toward the medial scapular incision, the autograft is shuttled and the stitched end of the autograft is fixed to the humeral head with a knotless anchor. With the shoulder in maximum external rotation and 0° of abduction, tenodesis of the autograft is performed to the lower trapezius tendon with a Pulvertaft technique. The shoulder is then immobilized in 40° to 60° of external rotation in a custom brace for 6 to 8 weeks. Passive and gradual active-assisted shoulder exercises should begin at 6 to 8 weeks postoperatively.

Alternatives: Surgical alternatives for irreparable tears include partial rotator cuff repair with biceps superior capsular reconstruction, superior capsular reconstruction with fascia lata graft, subacromial balloon spacer, and reverse shoulder arthroplasty. Tendon transfers are preferred in younger patients.

Rationale: The lower trapezius has adequate tension, a similar line of pull as the infraspinatus, and enough tension to replace the function of the infraspinatus¹. Biomechanical studies have shown that the maximum external rotation moment arm generated with use of a lower trapezius transfer with the arm at the side is superior to that with either latissimus dorsi or teres major transfer², and lower trapezius transfer is technically less cumbersome than other tendon transfer techniques.

Expected outcomes: Expected outcomes following the presently described procedure include significant improvements in pain and function. Elhassan et al.³ reported the outcomes of lower trapezius tendon transfer utilizing an allograft in 33 patients with an average age of 53 years (range, 31 to 66 years). At an average follow-up of 47 months, 32 patients had significant improvements in pain, SSV, and DASH score. One patient required debridement for an infection and later underwent shoulder arthrodesis. In a separate study, Elhassan et al.⁴ reported on 41 patients who underwent arthroscopically assisted lower trapezius transfer. Of these, 37 (90%) patients showed significant improvements in the VAS pain scale, SSV, and DASH scores. Two other patients with preoperative cuff arthropathy underwent reverse shoulder arthroplasty for persistent pain. The remaining 2 patients experienced a traumatic rupture, at 5 and 8 months postoperatively. Valenti and Werthel⁵ performed arthroscopically assisted lower trapezius transfer using hamstring graft in 14 patients with a mean age of 62 years (range, 50 to 70 years). Over a mean follow-up of 24 months (range, 12 to 36 months), the gain in external rotation was 24° with the arm at the side and 40° in 90° of abduction. Both the lag sign and hornblower sign were negative after this transfer. Two patients developed a hematoma, and a third patient underwent revision because of infection.

Important tips: Proper case selection is necessary for optimal results.Ensure adequate release from the scapular spine to avoid difficult lower trapezius tendon harvesting and suboptimal lower trapezius tendon excursion.Utilize a combination of suture anchors to overcome insufficient graft fixation to the greater tuberosity as a result of poor bone stock.Make an adequate window beneath the infraspinatus fascia and utilize special long curved forceps to avoid difficult peroneus graft passage.Perform multiple cycles of rotation before fixation to avoid insufficient graft tensioning and graft excursion prior to lower trapezius attachment.

Acronyms and abbreviations: SSV = Shoulder Subjective ValueVAS = visual analog scaleDASH = Disabilities of the Arm, Shoulder and HandSST = Simple Shoulder TestERMA = external rotation moment armADL =activities of daily livingMRI= magnetic resonance imagingPEEK= polyetheretherketonePLT= peroneus longus tendon.