Summary

Clinical and radiological outcomes following muscle advancement for massive posterosuperior rotator cuff tears.

Abstract

Introduction

Massive retracted posterosuperior cuff tears to the glenoid rim (with delamination) pose a challenge, they are associated with a high re-tear rate1. Primary repair of these tears is often complex due to inadequacy of stump length, peritendinous scarring and fibrosis, retraction, muscular fatty infiltration and poor tissue quality resulting in “irreparability”. These difficulties make primary repair a less-favourable option and promote other salvage procedures such as superior capsular reconstruction and tendon transfers. A tension free repair is mandatory for a successful outcome. Rather than pulling the tendon under tension, we have employed an all arthroscopic technique of releasing the cuff muscles off the scapular body allowing advancement the whole muscle-tendon unit laterally to achieve a tension-free footprint repair2. Clinical and radiological outcomes of all arthroscopic muscle slide and advancement is reported in this prospective study.

Methods

61 consecutive patients (66 shoulders) with large to massive delaminated posterosuperior cuff tears were enrolled. 47 (77%) were males. Mean age was 57 years (SD=6, range: 42-70). Nine (15%) were smokers. Mean BMI was 31.7 (SD=6.1, range: 21.6, 50.9). 56% of the cuff tears were in the dominant hand, and 83% of the cuff tears were traumatic.
These patients underwent an all-arthroscopic rotator cuff repair that included supraspinatus and infraspinatus subperiosteal dissection from their scapular bony fossae, lateral advancement of the tendon laminae, and tension-free double-layer Lasso Loop repair to the anatomical footprint.
59 shoulders (89%) were reviewed at a mean follow-up of 52.4 weeks (SD: 27.6 weeks, range: 20.3-175.1 weeks). Patients were radiologically assessed with a magnetic resonance imaging (MRI) at 6 months after the procedure. Pre-operative and Post-operative range of motion, cuff strength, VAS, Constant, ASES, and UCLA scores were assessed.
Pre-operative radiologic assessment with an MRI included Patte (modified by Boileau) classification of tendon retraction, and Goutallier classification of fatty degeneration. Cuff healing and integrity of repair was assessed using the Sugaya classification, wherein, Sugaya 4 and 5 were considered as re-tears.

Results

& Discussion
Advanced fatty degeneration (Goutallier 3 and 4) was present in 44% of supraspinatus and 20% of infraspinatus muscle bellies, respectively; while moderate degeneration (Goutallier 2) was present in 42% of supraspinatus and 22% of the infraspinatus muscle bellies, respectively. Tendon retraction was to the level of the glenoid (Patte-Boileau III-2) or medial to the glenoid (Patte-Boileau IV) in 22%, and just lateral to the glenoid (Patte-Boileau III-1) in 66%. About half of the tears (51%) extended into the teres minor. The subscapularis was partially torn (Lafosse 1-3) in 46% of cases and completely torn (Lafosse 4-5) in 20%.
At follow up, there was a statistically significant increase in the mean range of motion (Table 1). Relative cuff strength improved from 57% to 90%, when compared to contralateral side (Table 2). VAS improved statistically from 4±2.5 to 1±1.7 (p<0.001). There was a statistically significant improvement in all scores from preoperative to postoperative evaluations; Constant from 50 ± 17.8 to 74 ± 13.0 (p<0.001), ASES from 52 ± 17.5 to 87 ± 14.9 (p<0.001), and UCLA from 16 ± 4.9 to 30 ± 4.9 (p<0.001).
There were 6 re-tears (10%) with Sugaya 4 and 5 grades noted, one failure was due to P. acnes infection. 65% of patients were Sugaya 2. Stiffness occurred in 6 cases (10%) with 4 requiring arthrolysis. 93% returned to pre-injury work, and 89% of cases returned to pre-injury sport. The satisfaction rate was 96%.
Primary repair of massive posterosuperior cuff tears using the muscle advancement technique coupled with double-layer lasso loop repair leads to restoration of range of motion, symmetrical strength, and excellent functional outcomes.