Achilles Tendon–Bone Block Allograft for Massive Rotator Cuff Tears With Bony Deficiency of the Greater Tuberosity: A Minimum 2-Year Follow-up Study

Calcaneum-Achilles Tendon Allograft for Massive Posterosuperior Rotator Cuff Lesion With Bony Deficiency

Dealing with massive and irreparable rotator cuff tears presents intricate challenges. Concerning elder patients, either conservative management or reverse shoulder arthroplasty could be the most appropriate treatment. On the other hand, in younger patients, there is a wide spectrum of solutions, most of them being under evaluation and not completely validated. The complexity increases when a greater tuberosity avulsion occurs at the same time. Regardless of whether surgical fixation is performed, there is a risk for bone resorption, which would result in the posterosuperior cuff's insertion spot loss. In this case, the surgeon is expected to simultaneously manage the bone loss and the tendon tear. The Calcaneum-Achilles Tendon Allograft (CalATA) therefore appears to play an interesting role due to its solid bone-tendon structure. This Technical Note aims to present the CalATA technique, which consists in both tendon and bone deficiency restoration in massive rotator cuff tears with greater tuberosity resorption.

Enhancement of Tendon-to-Bone Healing: Choose a Monophasic or Hierarchical Scaffold?

BACKGROUND

To enhance the healing of tendon to bone, various biomimetically hierarchical scaffolds have been proposed. However, the fabrication of such scaffolds is complicated. Furthermore, the most significant result after a routine repair is loss of the transition zone between the tendon and bone, whose main components are similar to fibrocartilage.

PURPOSE

To compare tendon-to-bone healing results in a rabbit model using a monophasic graft (decellularized fibrocartilage graft; DFCG) and hierarchical graft (decellularized tendon-to-bone complex; DTBC) that contain the native hierarchical enthesis.

STUDY DESIGN

Controlled laboratory study.

METHODS

DFCG and DTBC were harvested from allogenic rabbits. A rabbit model of a chronic rotator cuff tear was established, and 3 groups were assessed: direct repair or repair with DFCG or DTBC fixed between the tendon and bone. Hierarchical evaluations of the repaired tendon-to-bone interface were performed with regard to the tendon zone, transition zone, and bone zone using histological staining and micro-computed tomography scanning. Biomechanical analysis was performed to evaluate the general healing strength.

RESULTS

The healing results in the tendon zone exhibited no significant difference among the 3 groups at any time point. In the transition zone, the grade in the direct repair group was significantly lower than that in the DFCG and DTBC groups at 4 weeks, and the grade in the DFCG group was significantly lower than that in the DTBC group at this time point. However, any significant difference between the DFCG group and DTBC group could no longer be detected at 8 and 16 weeks, which was inconsistent with the results of the biomechanical analysis. Micro-computed tomography analysis showed no significant difference among the 3 groups with regard to bone mineral density at 16 weeks.

CONCLUSION

A monophasic DFCG was able to achieve enhanced tendon-to-bone healing similar to that with hierarchical DTBC over the long term, with regard to both histological and biomechanical properties.

CLINICAL RELEVANCE

Fabrication of a monophasic scaffold instead of a hierarchical scaffold to promote regeneration and remodeling of a transition zone, which was mainly composed of fibrocartilaginous matrix between the tendon and bone, may be sufficient to enhance tendon-to-bone healing.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.