Revision Rotator Cuff Reconstruction for Large Tears With Retraction: A Novel Technique Using Autogenous Tendon and Autologous Marrow

Discussion

Primary rotator cuff surgery is beneficial.⁵ Irrespective of technique, open versus arthroscopic,⁶ single- versus double-row repair,⁷ the clinical results have been satisfactory.⁸ Nevertheless, the “tissue failure” rate of rotator cuff surgery (full-thickness discontinuity of rotator cuff) has been as high as 31% in primary repairs.⁹ In revision rotator cuff repair and reconstruction, the radiographic tissue failure rate has been even higher, particularly in the setting of chronic large tears with retraction, with tissue failure rates up to 91%.¹⁰ Although small to medium full-thickness tears and retears are well tolerated by patients with reduced activity levels,¹¹ and pain symptoms do not necessarily correlate with rotator cuff tear size,¹² large retracted full-thickness tears in active patients seldom result in optimal clinical outcomes or patient satisfaction.^13,14 In addition, although recurrent tearing does not preclude a satisfactory clinical result, maintenance of cuff tissue integrity tends to produce a better objective clinical score and a more desirable clinical outcome.²

Few evidence-based restorative solutions exist for large recurrent rotator cuff tears with retraction in active non­geriatric patients.¹⁵ The no-treatment option in this context may result in gradual enlargement of the tear, chronic pain, weakness, and progressive degeneration of the glenohumeral joint and acromiohumeral confluence—so-called rotator cuff arthropathy, for which reverse total shoulder arthroplasty is required.^16,17 Partial repair of a large rotator cuff tear by margin convergence, interval slide, split deltoid flap, or nonanatomical reinsertion may improve clinical outcome scores but may not alter or prevent the progressive degenerative changes associated with rotator cuff arthropathy.^18,19 Synthetic scaffolds with and without biological enhancement have been used with varying degrees of success, particularly pain improvement and tissue integration.²⁰ Nevertheless, the failure rate has been reported to be 17% to 51%,²¹ and no evidence exists that allograft augmentation improves functional outcomes.²² Tendon transfer using the latissimus dorsi has also proved to be a surgical alternative in younger, active patients.²³ However, dissection in this procedure is a major undertaking for both surgeon and patient—compared with the minimally invasive technique used in the present study.²⁴

I selected a cohort of active, symptomatic patients for application of a synthesis of accepted surgical techniques through a mini-open incision in order to improve the reliability of the surgical construct while minimizing surgical morbidity. Débridement of marginal tissue, safe mobilization of remaining cuff, and tension-free suture line using locking sutures maximized the mechanical strength of the construct.^25,26 Biological enhancement with autogenous tissue (the patient’s own biceps tendon) as graft material (scaffolding), as well as autologous concentrated marrow delivering viable responding cells and chemokine/cytokine biofactors, increased the probability of reparative activity at the graft site.²⁷ The net effect was consistent tissue healing at a biologically challenging locus. Nonenhanced biceps tendon grafting in the setting of “irreparable” primary rotator cuff repair has had a 40-year history of orthopedic utility and an excellent record of clinical success.²⁸ Nevertheless, the retear rate has been 7% to 30%.²⁹ There are no previous reports of biologically enhanced autogenous biceps tendon grafting for reconstruction of a torn rotator cuff, either primary or in the setting of chronic revision surgery.

Previous well-designed PRP enhancement studies in the context of primary rotator cuff repair failed to demonstrate a consistent benefit with concentrated platelet-only augmentation.^30,31 The shared experimental design of these published studies used intra-articular injection as the sole delivery method without guarantee that the injected platelets would migrate, adhere to, and persist at the intended destination, the healing edge of the rotator cuff. In the present study, extended exposure of the splayed tendon graft by incubation in concentrated marrow was specifically designed to increase the probability that biologically active components would settle at the desired location by cellular seeding and plasmatic imbibition.³² Furthermore, use of PRP for growth factor (platelet-derived, PDGF; basic fibroblast, bFGF; transforming, TGF-β; epidermal, EGF; vascular endothelial, VEGF; connective tissue, CTGF) therapy, in addition to pluripotential mesenchymal cells for marrow-derived stem cell therapy, is in theory biologically superior to use of PRP alone.^33,34

The recent expansion of information about biologics has generated much interest in augmentation of soft-tissue healing. Unfortunately, the optimal technique of using cellular processing to upregulate stem-cell capacity at the graft interface is yet to be defined.³⁵ Clinical studies using PRP and related products to promote tendon healing have been both inconsistent and contradictory with respect to benefit of outcome. As we have been unable to harness the biological potential of this medium, application of biologics in contemporary clinical orthopedics remains narrow, random, and infrequent. The technique presented in this clinical series appears to be a small advancement in a positive direction. The described construct provides a starting point for study, combining mechanical as well as biological steps to promote rotator cuff healing. The consistency of the outcome in a clinical model in which retearing is an expectation rather than an exception is noteworthy. The zero tissue failure rate at 1 to 4 years, compared with the literature values in similar patient cohorts, is very promising.³⁶ The clinical outcome as measured by validated shoulder scores is also comparable to literature outcome values.¹⁹ Also noteworthy is the dynamic stability the construct gives to the glenohumeral joint. Ideally, the reconstructed rotator cuff provides active force coupling with the deltoid, simulating normal shoulder biomechanics. At a minimum, the reconstructed cuff provides a viable passive barrier to superior migration of the humeral head—thus supporting the mechanical efficiency of the deltoid and preventing rotator cuff arthropathy.