Does Margin Convergence Reverse Pseudoparalysis in Patients with Irreparable Rotator Cuff Tears?
Authors: Inui Hiroaki , Yamada Jumpei , Nobuhara Katsuya 
Published: December 2020

Abstract

Background
Margin convergence has been shown to restore muscle tension in a cadaveric model of a rotator cuff tear. However, the clinical utility of this technique remains uncertain for patients with pseudoparalysis caused by an irreparable rotator cuff tear.

Questions/purposes
(1) For patients with massive irreparable rotator cuff tears, in what proportion of patients does margin convergence reverse pseudoparalysis? (2) In patients with massive irreparable rotator cuff tears, does margin convergence improve American Shoulder and Elbow Surgeons (ASES) scores? (3) What is the survivorship free from MRI evidence of retear after margin convergence?

Methods
Between 2000 and 2015, we treated 203 patients for pseudoparalysis with a rotator cuff tear. Pseudoparalysis was defined as active elevation less than 90° with no stiffness, which a physical therapist evaluated in the sitting position using a goniometer after subacromial injection of 10 cc lidocaine to eliminate pain. Of those, we considered patients who underwent at least 3 weeks of unsuccessful nonoperative treatment in our hospital as potentially eligible. Twenty-one percent (43 of 203) who either improved or were lost to follow-up within 3 weeks of nonoperative treatment were excluded. A further 12% (25 of 203) were excluded because of cervical palsy, axillary nerve palsy after dislocation or subluxation, and development of severe shoulder stiffness (passive shoulder elevation < 90°). Repair was the first-line treatment, but if tears were considered irreparable with the torn tendon unable to reach the original footprint after mobilizing the cuff during surgery, margin convergence was used. When margin convergence failed, the procedure was converted to hemiarthroplasty using a small humeral head to help complete the repair. Therefore, 21% (42 of 203) of patients treated with regular repair (18% [36 of 203]) or hemiarthroplasty (3% [6 of 203]) were excluded. That left 93 patients eligible for consideration. Of those, 13 patients were lost before the minimum study follow-up of 2 years or had incomplete datasets, and 86% (80 of 93) were analyzed (49 men and 31 women; mean age 68 ± 9 years; mean follow-up 26 ± 4 months). Seventy-six percent (61 of 80) were not evaluated in the last 5 years. We considered reversal of pseudoparalysis as our primary study outcome of interest; we defined this as greater than 90° active forward elevation; physical therapists in care measured this in the sitting position by using goniometers. Clinical outcomes were evaluated based on the ASES score from chart review, active ROM in the shoulder measured by the physical therapists, and the 8-month Kaplan-Meier survivorship free from MRI evidence of retear graded by the first author.

Results
Pseudoparalysis was reversed in 93% (74 of 80) patients, and improvement in ASES scores was observed at the final follow-up (preoperative 22 ± 10 to postoperative 62 ± 21, mean difference 40 [95% CI 35 to 45]; p < 0.01). The 8-month Kaplan-Meier survivorship free from MRI evidence of retear after surgery was 72% (95% CI 63% to 81%). There were no differences in clinical scores between patients with and without retears (intact ASES 64 ± 24, re-tear ASES 59 ± 10, mean difference 6 [95% CI -5 to 16]; p = 0.27).

Conclusion
Margin convergence can be a good option for treating patients with pseudoparalysis and irreparable rotator cuff tears despite the relatively high retear rates. The proportion of pseudoparalysis reversal was lower in patients with three-tendon involvement. Further studies will be needed to define the appropriate procedure in this group.

Level of Evidence
Level IV, therapeutic study.