Histological incorporation of acellular dermal matrix in the failed superior capsule reconstruction of the shoulder

Abstract

Background Superior capsule reconstruction addresses massive rotator cuff tears using allografts and aims to restore the natural superior constraint of the shoulder and therefore shoulder biomechanics and function. There is no evidence relating to the histological incorporation of these grafts. Methods 27 superior capsule reconstructions were performed between June 2016 and November 2017. Follow-up was with clinical assessment and Magnetic Resonance Imaging, to identify graft failure. Reverse total shoulder replacement was offered for ruptured grafts and the graft was sent for histological analysis along with the footprint of graft attachment where possible. Results Five patients (18.5%) had evidence of graft failure, three of whom (11.1%) underwent revision procedures. Of the five ruptures, four failed at the glenoid insertion, and one was an intra-substance tear. Histological analysis showed extensive fibroblastic infiltration. The intra-substance tear showed some vascularity at the medial and lateral ends, and one of the glenoid pull-outs demonstrated micro-calcification and osteoid formation. There was no evidence of in-growth into the bone. Discussion An inflammatory response to the grafts was seen, with neo-vascularisation, and micro-calcification observed. These findings are from ruptured grafts, so may not represent the characteristics of those which have not ruptured. Further evidence from explanted intact grafts could be gained to improve our understanding of its incorporation. Level of evidence Level IV evidence

Complications of Superior Capsule Reconstruction for the Treatment of Functionally Irreparable Rotator Cuff Tears: A Systematic Review

“…The overall rate of complications post-SCR ranged from 5.0% to 70.0% (I 2 ¼ 77.3%; Fig 2) (507 shoulders; Table 2). [36][37][38]44,51,52,[58][59][60][61][62][63][64][65] The complication rate in the 8 studies using allografts (289 shoulders) [36][37][38]44,51,59,62,65 ranged from 5% to 70% (I 2 ¼ 84.9%) while the complication rate of the 4 studies using autografts (176 shoulders) 52,58,63,64 ranged from 14% to 32% (I 2 ¼ 42.1%).…”

Donor-Site Morbidity After Autologous Fascia Lata Harvest for Arthroscopic Superior Capsular Reconstruction: A Midterm Follow-up Evaluation

“…Eight of these 9 studies reported a revision rate of 4% or less. ** In contrast, of the 16 clinical studies of ASCR that used allografts or xenografts published to date that reported a minimum follow-up of 6 months to 2 years, †† only 4 studies 13 , 29 , 41 , 50 reported an MRI evaluation of graft integrity for each of the enrolled patients, and the calculated graft tear proportion ranged from 18.5% to 50% in the first 6 to 12 months of follow-up. In the remaining 12 studies of ASCR that used allografts or xenografts, a selected subgroup of patients underwent MRI evaluation, resulting in a proportion that reflects only this selected subgroup’s graft tear rate.…”

Histologic case series of human acellular dermal matrix in superior capsule reconstruction

“…Numerous studies have confirmed that SCR is a successful treatment for irreparable rotator cuff tears in the short term based on patient-reported outcome scores, MRI, and plain radiographs. 3,7,8,10,15 Aside from a few case reports, there has been a paucity of direct confirmation regarding the integration and recellularization of the ADM. 2,7,16,17 This case series examined the histology of whole or large segments of SCR explants from 8 patients of a wide age range, as well as from a multitude of time points after implantation. It represents a significant advancement in our knowledge regarding biologic incorporation of ADMs used in SCR.…”

“…Finally, in a small case series, Ravencroft et al 17 followed 27 total patients who had SCR in 2016-2017. During follow-up MRIs, 5 procedures were labeled as failures.…”

“…It has been suggested that in some cases of clinical failure in which the graft was intact, the failure was a result of improper tensioning, which failed to restore acromial-humeral distance. 9 Ravenscroft et al 17 concluded that these results provided evidence that the ADM used acted as a ''good biologic scaffold.'' Altogether, these findings from the literature support the use of decellularized dermal matrix as a bridging graft in SCR and suggest its utility as a scaffold for tissue regeneration.…”