These biomechanical studies have been translated to clinical findings. A level II, prospective, randomized controlled study by Barber and colleagues29 evaluated 42 patients with >3 cm, 2-tendon RCTs repaired arthroscopically.Twenty-two patients were randomized to single-row arthroscopic repair, and 20 patients to single-row arthroscopic repair augmented by ADM by an onlay technique (Figure 1) as described by Labbé.30 At average follow-up of 24 months, 85% of the augmented repairs were intact on magnetic resonance imaging (MRI) at follow-up, compared to 40% in the control group (P < .05). Agrawal31 retrospectively reviewed 14 patients with either RCTs >3 cm or recurrent RCT (may be <3 cm) that were arthroscopically repaired with a double-row technique with ADM augmentation. Postoperative MRI obtained at average of 16.8 months revealed 85.7% of repairs to be intact, with 14.3% having recurrent tears of <1 cm. Rotini and colleagues32 evaluated a smaller subset of 5 patients with large/massive primary cuff tears, arthroscopically repaired with double-row technique and ADM augmentation. Follow-up MRI at an average of 1 year demonstrated 3 intact repairs, 1 partial recurrence, and 1 complete recurrence. These clinical studies demonstrate that RCRs augmented with ADM have a much higher rate of structural integrity on postoperative imaging compared to what has been previously reported in the literature.1-6
Although an “off-label” indication, the use of ADM in massive RC tears has been described with good clinical results.14,17,19,33 The ADM is used to bridge the gap by suturing it to the edge of the retracted tendon and anchoring it to the tuberosity (Figures 2A-2E). Improvement in pain, function, and active range of motion can be achieved. Burkhead and colleagues14 obtained postoperative MRIs at average follow-up of 1.2 years and found only 3 of 11 repairs with evidence of re-tear, all noted to be smaller than preoperative tears. Gupta and colleagues17 obtained postoperative ultrasounds in 24 patients at average 3 years and showed 76% of tears to be fully intact, with the remaining 24% having only a partial tear, and 0% with full re-tears. Venouziou and colleagues19 evaluated 14 patients with minimum 18-month follow-up and Kokkalis and colleagues33 evaluated 21 patients with a 29-month follow-up; both described successful clinical outcomes but did not provide postoperative imaging evaluation. Multiple studies have adapted this technique to a fully arthroscopic method and have had similarly positive results clinically and with MRI.13,16,18,34,35 Bond and colleagues13 reported 16 cases with massive irreparable tears repaired arthroscopically with ADM to span the tendon gap. At an average follow-up of 26.8 months, 75% had good or excellent clinical results, and at an average of 1 year postoperatively 13 of 16 cases had an intact repair on gadolinium enhanced MRI.13 These studies suggest that ADM can be used for bridging massive irreparable RC tears with good clinical and radiographic outcomes.
Superior capsule reconstruction is a biomechanically proven concept that has been described in previous studies.36,37 In the original technique, autologous tensor fascia lata (TFL) is anchored from the glenoid margin to the greater tuberosity footprint to restore the superior stability of the glenohumeral joint, without altering the native glenohumeral contact forces.38 This concept has gained popularity in the United States, but with the use of an ADM instead of harvesting TFL (Figures 3A, 3B). However, there are no published biomechanical or clinical studies with the use of ADM in superior capsular reconstruction.
Conclusion
The use of ADM is an emerging solution for augmenting primary RCRs and the treatment of irreparable RC tears. The biomechanical and clinical studies summarized support the use of ADM in RC surgery. Further randomized studies are needed to add to the growing evidence on the use of ADMs.