Reverse total shoulder arthroplasty with the Tornier Perform implant with lower trapezius transfer for symptomatic rotator cuff deficiency with external rotation lag and Hornblower's sign.

BACKGROUND: Reverse total shoulder arthroplasty (rTSA) is a well-established treatment for cuff tear arthropathy and consistently restores active forward elevation. However, when there is a deficiency of the posterior rotator cuff (infraspinatus and teres minor), patients can exhibit lag signs at the side and a "Hornblower's sign." This loss of active external rotation (ER) in abduction can be functionally disabling, and rTSA alone may not reliably restore active ER ability in this clinical scenario. We present a series of rTSA with lower trapezius transfer (LTT) (utilizing tibialis anterior allograft) as the primary surgery for patients with a combined loss of active elevation and severe loss of active ER, both at the side and in elevation.

METHODS: Twelve patients (11 males and 1 female) underwent rTSA with the Tornier Perform implant with LTT (11 with tibialis anterior, 1 Achilles tendon allograft). The average patient age was 68.6 years (52.4-82.8), and the average follow-up was 35.4 months (24-52 months). All had a loss of active ER, with the average active ER at the side being -10.8° (-30 to 20). The average preoperative active elevation was 58.3° (30-90). Preoperative patient-reported outcome scores were American Shoulder and Elbow Surgeons: 46.8 (±19.82), Single Assessment Numeric Evaluation: 32.8 (±17.09), and visual analog scale for pain: 4.9 (±2.88). Preoperatively, all exhibited an external rotation lag sign at the side and the "Hornblower's sign" with the forearm falling into internal rotation with elevation. Magnetic resonance imaging revealed irreparable cuff tears involving the supraspinatus and infraspinatus. In all cases, the infraspinatus and teres minor had significant atrophy and/or fatty infiltration.

RESULTS: All patients could actively elevate and keep the forearm pointed to the ceiling in the scapular plane following surgery, thus eliminating the "Hornblower's sign." The average postoperative active forward elevation and active ER at the side were 141.3° (100-170, P < .0001) and 35.0° (15-45, P < .0001), respectively. Postoperative outcome scores averaged: American Shoulder and Elbow Surgeons: 81.9 (±11.9, P < .0001), Single Assessment Numeric Evaluation: 67.7 (±28.9, P = .0019), visual analog scale for pain: 1.0 (±1.6, P = .0004).

DISCUSSION AND CONCLUSION: rTSA with latissimus dorsi transfer has been utilized to address a combined loss of elevation and ER. LTT has been described for rotator cuff deficient shoulders without arthritis to restore ER ability without a prosthetic implant. This series, with early-term follow-up, reports the results of rTSA with LTT to restore ER ability in severely dysfunctional shoulders. Consistent functional results and high patient satisfaction were obtained with rTSA and LTT with a tibialis anterior tendon allograft in patients with a combined loss of elevation and ER. The lag signs and the Hornblower's sign were eliminated in all patients.