Biphasic Interpositional Allograft for Rotator Cuff Repair Augmentation Is Safe in an Ovine Model

Inlay Scaffold Augmentation of Rotator Cuff Repairs Enhances Histologic Resemblance to Native Enthesis in Animal Studies: A Systematic Review

PURPOSE

To investigate the outcomes of inlay positioned scaffolds for rotator cuff healing and regeneration of the native enthesis after augmentation of rotator cuff tendon repairs in preclinical studies.

METHODS

A literature search was performed using the PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature databases according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Preclinical studies reporting on outcomes after inlay tendon augmentation in rotator cuff repair were included. Preclinical study quality was assessed using an adapted version of the Gold Standard Publication Checklist for animal studies. The level of evidence was defined based on the inclusion of clinical analyses (grade A), biomechanical analyses (grade B), biochemical analyses (grade C), semiquantitative analyses (grade D), and qualitative histologic analyses (grade E).

RESULTS

Thirteen preclinical studies met the inclusion criteria. Quality assessment scores ranged from 4 to 8 points, and level-of-evidence grades ranged from B to E. Sheep/ewes were the main animal rotator cuff tear model used (n = 7). Demineralized bone matrix or demineralized cortical bone was the most commonly investigated scaffold (n = 6). Most of the preclinical evidence (n = 10) showed qualitative or quantitative differences regarding histologic, biomechanical, and biochemical outcomes in favor of interpositional scaffold augmentation of cuff repairs in comparison to controls.

CONCLUSIONS

Inlay scaffold positioning in preclinical studies has been shown to enhance the healing biology of the enthesis while providing histologic similarities to its native 4-zone configuration.

CLINICAL RELEVANCE

Although onlay positioned grafts and scaffolds have shown mixed results in preclinical and early clinical studies, inlay scaffolds may provide enhanced healing and structural support in comparison owing to the ability to integrate with the bone-tendon interface.

Augmentation Techniques for Rotator Cuff Repairs

» Despite enhanced understanding of risk factors for failure and enhanced surgical repair techniques, the risk for failure of the rotator cuff to heal after surgery is still substantial.» A patient-specific approach to augmentation is essential, with decisions based on tear and patient characteristics.» Augmentation can improve repair strength and promote cellular infiltration, which collectively contribute to better healing outcomes.» Augmentation strategies may improve outcomes in rotator cuff repairs, particularly in high-risk cases; however, there is a lack of consensus among surgeons on the most effective strategies for each scenario.

Reconstruction of the Superior Capsule Using Peroneus Longus Tendon Graft Combined With Transposition of Biceps Tendon for Irreparable Massive Rotator Cuff Tears

BACKGROUND

Traditional superior capsular reconstruction (SCR) with biceps tendon transposition (TB) alone for irreparable massive rotator cuff tears (IMRCTs) has demonstrated a high retear rate, highlighting the need for alternative approaches. Therefore, SCR using a peroneus longus tendon graft (PLG) combined with TB (PLG-TB) should be clinically studied.

PURPOSE

To compare the clinical and radiological outcomes of SCR using the PLG-TB technique versus the TB technique alone for IMRCT.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between February 2017 and March 2022, 94 patients were diagnosed with IMRCT; 45 patients underwent SCR using the TB technique (group 1), and 49 patients underwent SCR using the PLG-TB technique (group 2). The choice of technique was based on tendon damage severity and patient preference. After a minimum follow-up period of 2 years, postoperative clinical outcomes were compared using the American Shoulder and Elbow Surgeons (ASES); University of California, Los Angeles (UCLA); Constant; and visual analog scale (VAS) for pain scores as well as the shoulder range of motion. The integrity of tendons, acromiohumeral distance, and retear was evaluated through magnetic resonance imaging (MRI).

RESULTS

The mean follow-up times were 35.2 ± 4.2 months for group 1 and 34.1 ± 3.2 months for group 2. There was a significant improvement observed in all clinical outcomes in both groups from the baseline preoperative evaluations to the final follow-up assessments (P = .001 for ASES score, UCLA score, Constant score, VAS score, forward flexion, abduction, and external rotation). Shoulder abduction in group 2 showed statistically significant mean improvements at the postoperative 3-month, 6-month, and final follow-ups compared with group 1 (3 months: 105.17°± 7.13° vs 89.34°± 7.34° [P = .001]; 6 months: 138.14°± 9.12° vs 107.35°± 8.54° [P = .001]; final follow-up: 157.35°± 8.11° vs 135.31°± 7.01° [P = .001]). The tendon integrity at the final follow-up (Sugaya MRI grades 1/2/3/4/5) was significantly better in group 2 (30/6/6/4/3) compared with group 1 (11/13/5/6/10) (P = .014). Additionally, the tendon retear rate was lower in group 2 (7/49; 14.29%) than in group 1 (16/45, 35.56%) (P = .015).

CONCLUSION

Both surgical techniques led to acceptable clinical outcomes in patients with IMRCT. However, using the PLG-TB technique for SCR was associated with lower retear rates and enhanced abduction function outcomes compared with the TB technique for SCR.

Arthroscopic Transosseous-Equivalent Double-Row Rotator Cuff Repair Augmentation With Interpositional Demineralized Bone Fiber Implant

Failure of rotator cuff repairs contributes to decreased patient satisfaction and quality of life. Biologic enhancement of repairs represents a novel augmentation strategy attempting to reproduce native healing while concomitantly potentially decreasing the existing high failure rates associated with rotator cuff repairs. Scaffolds placed on top of the rotator cuff have been widely studied, yet no recreation of the native enthesis is achieved via this augmentation strategy. Several strategies involving placement of demineralized bone matrix scaffolds on an inlay configuration (between bone and tendon) have been reported demonstrating enhanced recreation of the native bone-tendon unit. This Technical Note describes the surgical technique of inlay demineralized bone fiber scaffold augmentation of rotator cuff repairs to enhance biological healing in aims of recreating the native enthesis.

Tissue-engineered collagen matrix loaded with rat adipose-derived stem cells/human amniotic mesenchymal stem cells for rotator cuff tendon-bone repair

The rotator cuff tendon-bone interface tissue exhibits high heterogeneity in its composition and structure, with collagen being its primary component. Here, we prepared tissue-engineered decellularized live hyaline cartilage grafts (dLHCG), this dLHCG scaffold's bioactive ECM mainly consists of collagen II, proteoglycans, and fibronectin, presenting a cartilage-like lacuna microstructure. The dLHCG scaffold loaded human amniotic mesenchymal stem cells (hAMSCs) and adipose stem cells (ADSCs) were implanted into the interface. The dLHCG scaffold could maintain the pluripotency of stem cells, supporting the proliferation, osteogenic differentiation, and tenogenic differentiation of the MSCs. The collagen II, through the integrin α2β1-FAK-JNK signaling axis, promotes Runx-2 activation, playing a better regulatory role in the early osteogenic differentiation of MSCs, enhancing bone defect repair through an endochondral ossification process. The in vivo rat model demonstrated that 12 weeks post-operation, the MSC-loaded dLHCG scaffold group exhibited continuous aligned collagen fibers at the tendon-bone interface, with significantly enhanced biomechanical function compared to the control group. The dLHCG scaffold create an efficient interface, which promoting the restoration of the soft-hard gradient structure tissue at the junction between the scaffold and the host tissue, thereby providing a rational and promising strategy for the rapid healing of the rotator cuff injury.

Decellularized biological matrices for the repair of rotator cuff lesions: a systematic review of preclinical in vivo studies

Background: Rotator cuff tears (RCTs), resulting from degeneration or trauma of the shoulder tendons, are one of the main causes of shoulder pain. In particular, massive RCTs represent 40% of all injuries, require surgical treatment, and are characterized by poor clinical outcomes and a high rate of failure. In recent years, the use of biological decellularized patches for augmentation procedures has received great interest owing to their excellent self-integration properties, improving healing and, thus, presenting an innovative therapeutic option. However, the findings from clinical studies have emerged with conflicting viewpoints regarding the benefits of this procedure, as an excessive tension load might compromise the integrity of the tendon-to-bone connection when the patch exhibits low elasticity or insufficient strength. This could prevent the healing process, leading to unpredictable results in clinical practice. Methods: This systematic review was conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines across three databases (PubMed, Scopus, and Web of Knowledge) to underline the results obtained in preclinical studies involving animal models of RCT surgeries that utilized the biological decellularized matrix augmentation technique in the last 5 years. Results: Thirteen articles were included after the screening, and the SYRCLE tools were applied to assess the risk of bias in in vivo studies. Open-surgery techniques were conducted to create tendon defects or detachment in different animal models: rat (31%), rabbit (46%), dog (15%), and sheep (8%). Patches decellularized with non-standardized protocols were used in 77% of studies, while commercially available matrices were used in 15%. Of the studies, 31% used allogenic patches, 61% used xenogenic patches, and 8% utilized both xenogenic and autologous patches. Conclusion: Overall, this review provides a comprehensive overview of the use of acellular patches and their effective therapeutic potential in rotator cuff (RC) repair at the preclinical level with the aim of expanding the strategies and matrices available for surgeons. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023468716.

Editorial Commentary: A Biphasic (Calcified and Demineralized), Cancellous, Interpositional Allograft Augmenting Rotator Cuff Repair in an Ovine Model Does Not Show Harmful Inflammation or Foreign Body Reaction

To improve the outcomes of arthroscopic rotator cuff (RC) repair, it is important to achieve tendon-to-bone healing at the repair site. Healed repairs are more likely to restore shoulder strength and lead to higher magnitudes of satisfaction. Patches or grafts that can be either secured to the bursal surface of the RC or interposed between the RC tendon and greater tuberosity at the time of repair have been described as adjuncts to RC repair. A cancellous, biphasic allograft tissue composed of 2 layers (calcified to promote osseointegration and demineralized to support soft-tissue ingrowth) has been shown to be safe in an ovine model, without a harmful inflammatory or foreign body response. Human trials may be a reasonable next step.