Rotator cuff repair with biological graft augmentation causes adverse tissue outcomes

Assessing Bioprinted Functionalized Grafts for Biological Tendon Augmentation In Vitro

Tendinopathy, characterized by inflammatory and degenerative changes, presents challenges in sports and medicine. In addressing the limitations of conservative management, this study focuses on developing tendon grafts using extrusion bioprinting with platelet-rich plasma (PRP)-infused hydrogels loaded with tendon cells. The objective is to understand paracrine interactions initiated by bioprinted tendon grafts in either inflamed or non-inflamed host tissues. PRP was utilized to functionalize methacrylate gelatin (GelMA), incorporating tendon cells for graft bioprinting. Bioinformatic analyses of overexpressed proteins, predictive of functional enrichment, revealed insights into PRP graft behavior in both non-inflamed and inflamed environments. PRP grafts activated inflammatory pathways, including Interleukin 17 (IL-17), neuroinflammation, Interleukin 33 (IL-33), and chemokine signaling. Interleukin 1 beta (IL-1b) in the graft environment triggered p38 mitogen-activated protein kinase (MAPK) signaling, nuclear factor kappa light chain enhancer of activated B cells (NF-kB) canonical pathway, and Vascular Endothelial Growth Factor (VEGF) signaling. Biological enrichment attributed to PRP grafts included cell chemotaxis, collagen turnover, cell migration, and angiogenesis. Acellular PRP grafts differed from nude grafts in promoting vessel length, vessel area, and junction density. Angiogenesis in cellular grafts was enhanced with newly synthesized Interleukin 8 (IL-8) in cooperation with IL-1b. In conclusion, paracrine signaling from PRP grafts, mediated by chemokine activities, influences cell migration, inflammation, and angiogenic status in host tissues. Under inflammatory conditions, newly synthesized IL-8 regulates vascularization in collaboration with PRP.

Interposition of acellular amniotic membrane at the tendon to bone interface would be better for healing than overlaying above the tendon to bone junction in the repair of rotator cuff injury

PURPOSE

The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair.

METHODS

Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference.

RESULTS

AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively).

CONCLUSION

In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.

Outcomes of arthroscopic single-row repair alone vs. repair with human dermal allograft patch augmentation in patients with large to massive, posterosuperior rotator cuff tears: a retrospective comparative study

BACKGROUND

Large to massive rotator cuff tears (RCTs) affect shoulder functions profoundly with unmanageable disability without intervention. The retear rates with arthroscopic rotator cuff repair (ARCR) in these patients are abysmal. Patch augmentation has been credited for preventing retears, improving functions by increasing the strength, and acting as a bioconductive scaffold. This study aimed to assess the retear rates and compare the clinical and radiological outcomes between the ARCR with and without acellular human dermal allograft (HDA) augmentation.

METHODS

This is a retrospective comparative study among patients diagnosed with large to massive, posterosuperior RCTs, operated between January 2020 and December 2021, including 36 patients (group I) with and 131 patients (group II) without HDA augmentation, with a mean follow-up of 20 (range, 12-35) months. The average age was 64 (range, 49-80) and 66 (range, 41-81) years in groups I and II, respectively. In group I, there were 16 male and 20 female patients, whereas in group II, there were 58 male and 73 female patients.

RESULTS

The visual analog scale score improved to 1.1 ± 1.7 in group I and 2.1 ± 1.7 in group II (P = .005). There was a greater improvement in the University of California, Los Angeles shoulder score to 30.1 ± 4.2 in group I compared with 23.2 ± 3.9 in group II (P = .046). Forward flexion (degrees) improved from a mean of 103.2 ± 18.6 to 138.9 ± 23.5 in group I and from 106.4 ± 21.3 to 127.0 ± 19.5 in group II (P = .004). The acromiohumeral interval (mm) measured in anteroposterior radiographs increased to 8.4 ± 1.8 in group I and 8.2 ± 2.0 in group II (P = .006). The satisfaction after the procedure was 4.4 ± 0.6 in group I and 3.1 ± 1.1 in group II (P = .044). The retear rate in the HDA-augmented group was 5.6% as compared with 29.1% in the nonaugmented group, which was statistically significant (P = .007). There were no complications or adverse tissue reactions against HDA seen in any patients.

CONCLUSION

In patients with large to massive, posterosuperior RCTs, patch augmentation with acellular HDA significantly averted the retears after ARCR without any graft-related complications. The augmentation also resulted in improved shoulder function and greater range of motion compared with the nonaugmented group.

Current Understanding and New Advances in the Surgical Management of Reparable Rotator Cuff Tears: A Scoping Review

Rotator cuff (RC) tears are among the most common musculoskeletal disorders and can be associated with pain, weakness, and shoulder dysfunction. In recent years, there have been significant advances with regard to the understanding of rotator cuff disease and its management. With technological improvements and advanced diagnostic modalities, there has been much progress as to improved understanding of the pathology. Similarly, with advanced implant designs and instrumentation, operative techniques have evolved. Furthermore, refinements in postoperative rehabilitation protocols have improved patient outcomes. In this scoping review, we aim to provide an overview of the current knowledge on the treatment of rotator cuff disorders and to highlight recent advances in its management.

Double-Row Rotator Cuff Repair Technique With Dermal Allograft Augmentation

Rotator cuff tears are common and debilitating injuries in the orthopaedic patient population. Although arthroscopic repair of the rotator cuff generally leads to satisfactory outcomes, some tears would benefit from augmentation with allograft to supplement the native tissue. This biological augmentation has been shown to decrease retear rates and can be beneficial in certain cases based on the size of the tear, amount of retraction, age of the patient, and chronicity. In this technical note, we describe a simple and effective technique for arthroscopic rotator cuff repair with biological augmentation.

Aktuelle Aspekte der Behandlung der Rotatorenmanschette

Rotatorenmanschettenrupturen gehören zu den häufigsten muskuloskeletalen Erkrankungen und können mit ausgeprägten Schmerzen und Funktionseinschränkungen einhergehen. Für ihre Entstehung ist eine Vielzahl von Faktoren relevant, u. a. die individuelle Anatomie des Akromions. Mit Hilfe der heutigen technischen Möglichkeiten wurde nun festgestellt, dass zusätzlich zu seiner lateralen Ausdehnung auch die sagittale Ausdehnung des Akromions eine Rolle zu spielen scheint. Die bildgebende Darstellung der Rotatorenmanschette (RM) hat von den technischen Fortschritten der letzten Jahrzehnte ebenfalls profitiert. Magnetresonanztomographie (MRT) und MR-Arthrographie werden heute flächendeckend eingesetzt. Letztere bietet die höchste Sensitivität für die Entdeckung selbst kleiner Partialläsionen. Neue Sequenzen und Nachbearbeitungsmöglichkeiten können als hilfreiche tools für die operative Planung eingesetzt werden. Grundsätzlich richtet sich die Behandlung der RM neben der Symptomatik nach der Rupturgenese und -morphologie sowie der erwarteten Gewebequalität des Muskel-Sehnen-Kontinuums. Auch das Gesamtprofil, die Erwartungshaltung und die Rehabilitationsmöglichkeiten des Patienten sind wichtig. Die heutigen operativen Techniken werden durch spannende Entwicklungen der Industrie mitbestimmt, die in den letzten Jahren immer bessere Fadenankersysteme, aber auch Augmentationsmaterialien auf den Markt gebracht hat. Letztere zielen nicht nur auf die mechanische Verstärkung der Sehnenrekonstruktion, sondern auch auf die Optimierung der biologischen Eigenschaften des Konstrukts ab. Hinsichtlich Fixation konnte die biomechanische Forschung zeigen, dass zweireihige oder Suture-Bridge-Fixationen einreihigen oder transossären Fixationen überlegen sind. Diese Überlegenheit im Labor spiegelt sich noch nicht klar in den klinischen Ergebnissen wider, dennoch sind die meisten Chirurgen heute auf diese Technik übergegangen. Was die postoperative Nachbehandlung angeht, stellen jüngste randomisiert-kontrollierte Untersuchungen das Konzept der postoperativen Immobilisation in Abduktion in Frage. Hier scheint das letzte Wort noch nicht gesprochen zu sein.

Rotator Cuff Repair With Patch Augmentation: What Do We Know?

BACKGROUND

Repair of massive rotator cuff tears remains a challenging process with mixed success. There is a growing interest in the use of patches to augment the repair construct and the potential to enhance the strength, healing, and associated clinical outcomes. Such patches may be synthetic, xenograft, or autograft/allograft, and a variety of techniques have been tried to biologically enhance their integration and performance. The materials used are rapidly advancing, as is our understanding of their effects on rotator cuff tissue. This article aims to evaluate what we currently know about patch augmentation through a comprehensive review of the available literature.

METHODS

We explore the results of existing clinical trials for each graft type, new manufacturing methods, novel techniques for biological enhancement, and the histological and biomechanical impact of patch augmentation.

RESULTS

There are promising results in short-term studies, which suggest that patch augmentation has great potential to improve the success rate. In particular, this appears to be true for human dermal allograft, while porcine dermal grafts and some synthetic grafts have also had promising results.

CONCLUSION

However, there remains a need for high-quality, prospective clinical trials directly comparing each type of graft and the effect that they have on the clinical and radiological outcomes of rotator cuff repair.

Clinical perspectives for repairing rotator cuff injuries with multi-tissue regenerative approaches

Background

In the musculoskeletal system, bone, tendon, and muscle form highly integrated multi-tissue units such as the rotator cuff complex, which facilitates functional and dynamic movement of the shoulder joint. Understanding the intricate interplay among these tissues within clinical, biological, and engineering contexts is vital for addressing challenging issues in treatment of musculoskeletal disorders and injuries.

Methods

A wide-ranging literature search was performed, and findings related to the socioeconomic impact of rotator cuff tears, the structure-function relationship of rotator cuff bone-tendon-muscle units, pathophysiology of injury, current clinical treatments, recent state-of-the-art advances (stem cells, growth factors, and exosomes) as well as their regulatory approval, and future strategies aimed at engineering bone-tendon-muscle musculoskeletal units are outlined.

Results

Rotator cuff injuries are a significant socioeconomic burden on numerous healthcare systems that may be addressed by treating the rotator cuff as a single complex, given its highly integrated structure-function relationship as well as degenerative pathophysiology and limited healing in bone-tendon-muscle musculoskeletal tissues. Current clinical practices for treating rotator cuff injuries, including the use of commercially available devices and evolving trends in surgical management have benefited patients while advances in application of stem/progenitor cells, growth factors, and exosomes hold clinical potential. However, such efforts do not emphasize targeted regeneration of bone-tendon-muscle units. Strategies aimed at regenerating bone-tendon-muscle units are thus expected to address challenging issues in rotator cuff repair.

Conclusions

The rotator cuff is a highly integrated complex of bone-tendon-muscle units that when injured, has severe consequences for patients and healthcare systems. State-of-the-art clinical treatment as well as recent advances have resulted in improved patient outcome and may be further enhanced by engineering bone-tendon-muscle multi-tissue grafts as a potential strategy for rotator cuff injuries.

Translational Potential of this Article

This review aims to bridge clinical, tissue engineering, and biological aspects of rotator cuff repair and propose a novel therapeutic strategy by targeted regeneration of multi-tissue units. The presentation of these wide-ranging and multi-disciplinary concepts are broadly applicable to regenerative medicine applications for musculoskeletal and non-musculoskeletal tissues.

Injection of adipose stem cells in the treatment of rotator cuff disease - a narrative review of current evidence

The purpose of this study is to summarize evidence for the use of adipose stem cell (ASC) injections in the treatment of rotator cuff tears (RCT) and identify future areas of study. A thorough literature search was performed to identify studies investigating the use of ASC injections in the treatment of RCTs. Among animal trials, it is unclear whether ASCs are of benefit for rotator cuff repair. In clinical trials, ASC injection may reduce retear rate with otherwise equivocal clinical outcomes. Although ASC injection may be safe, the literature does not provide a clear consensus as to the efficacy of ASC injections, nor does it delineate which patients would benefit most from this treatment.

Decellularized Human Umbilical Cord Wharton Jelly Scaffold Improves Tendon Regeneration in a Rabbit Rotator Cuff Tendon Defect Model

BACKGROUND

Owing to limited self-healing capacity, failure of rotator cuff tendon healing is a common complication after surgery. Biological scaffolds have garnered attention owing to their potential to enhance healing outcomes.

PURPOSE

To verify the effect of the decellularized umbilical cord Wharton jelly (DUCWJ) scaffold as a bridging scaffold in a rabbit model of acute rotator cuff tendon defect.

STUDY DESIGN

Controlled laboratory study.

METHODS

We fabricated a DUCWJ scaffold using a physicochemical decellularized method, evaluating changes in the umbilical cord Wharton jelly before and after decellularization. Scanning electron microscopy and biomechanical testing were performed to determine the microstructure and mechanical properties. We assessed cytocompatibility and cell regulatory behavior of the scaffold toward tendon stem/progenitor cells (TSPCs). A supraspinatus tendon defect was created in 54 New Zealand White rabbits, allocated to the DUCWJ scaffold repair group and the negative control group (without scaffold). Histology, reverse transcription polymerase chain reaction, and biomechanical tensile strength were assessed at 4, 8, and 12 weeks postoperatively.

RESULTS

Decellularization completely removed cells from the umbilical cord Wharton jelly, retained a considerable amount of glycosaminoglycan and collagen, and preserved the microstructure and tensile strength. The DUCWJ scaffold facilitated migration and proliferation of TSPCs in vitro. Tendon-related gene expression revealed that the DUCWJ scaffold could maintain the tenocyte phenotype of TSPCs. In the in vivo study, the DUCWJ scaffold improved tendon healing and enhanced the biomechanical strength of repaired tendons. Histological evaluation scores of the DUCWJ group were significantly higher than those of the negative control at 4, 8, and 12 weeks after surgery (P < .05). In repaired tendon tissues, reverse transcription polymerase chain reaction findings revealed that the DUCWJ scaffold stimulated tendon development and maturation. Furthermore, an overall increase in ultimate load and tensile modulus was noted over time; the DUCWJ group presented better results than the negative control group (P < .05).

CONCLUSION

The DUCWJ scaffold has an excellent 3-dimensional porous structure, good biocompatibility, and fundamental biomechanical characteristics, and it promotes migration, attachment, and proliferation of TSPCs. The in vivo animal study demonstrated that the DUCWJ scaffold has potential for tendon regeneration in an acute rotator cuff tendon defect model.

CLINICAL RELEVANCE

DUCWJ scaffolds have potential as a regenerative material to augment rotator cuff healing in the clinical setting.

A bio-inductive collagen scaffold that supports human primary tendon-derived cell growth for rotator cuff repair

Background

Rotator Cuff (RC) tendon tearing is a common clinical problem and there is a high incidence of revision surgery due to re-tearing. In an effort to improve patient outcome and reduce surgical revision, scaffolds have been widely used for augmentation of RC repairs. However, little is known about how scaffolds support tendon stem cell growth or facilitate tendon regeneration. The purpose of this study is to evaluate the structural and biological properties of a bioactive collagen scaffold (BCS) with the potential to promote tendon repair. Additionally, we conducted a pilot clinical study to assess the safety and feasibility of using the BCS for repair of RC tears.

Methods

A series of physical, ultrastructural, molecular and in vitro tests determined the biocompatibility and teno-inductive properties of this BCS. In addition, a prospective case study of 18 patients with RC tendon tears (>20 ​mm in diameter) was performed in an open-label, single-arm study, involving either mini-open or arthroscopic surgical RC repair with the BCS. Clinical assessment of RC repair status was undertaken by MRI-imaging at baseline, 6 and 12 months and patient evaluated questionnaires were taken at baseline as well as 3, 6 & 12 months.

Results

The BCS consists of highly purified type-I collagen, in bundles of varying diameter, arranged in a higher order tri-laminar structure. BCS have minimal immunogenicity, being cell and essentially DNA-free as well as uniformly negative for the porcine α-Gal protein. BCS seeded with human primary tendon-derived cells and exposed to 6% uniaxial loading conditions in vitro, supported increased levels of growth and proliferation as well as up-regulating expression of tenocyte differentiation marker genes including TNMD, Ten-C, Mohawk and Collagen-1α1. To test the safety and feasibility of using the BCS for augmentation of RC repairs, we followed the IDEAL framework and conducted a first, open-label single arm prospective case series study of 18 patients. One patient was withdrawn from the study at 3 months due to wound infection unrelated to the BCS. The remaining 17 cases showed that the BCS is safe to be implanted. The patients reported encouraging improvements in functional outcomes (ASES, OSS and Constant-Murley scores), as well as quality of life assessments (AQoL) and a reduction in VAS pain scores. MRI assessment at 12 months revealed complete healing in 64.8% patients (11/17), 3 partial thickness re-tears (17.6%) and 3 full thickness re-tears (17.6%).

Conclusion

The BCS is composed of type-I collagen that is free of immunogenic proteins and supports tendon-derived cell growth under mechanical loading in vitro. This pilot study shows that it is safe and feasible to use BCS for RC argumentation and further controlled prospective studies are required to demonstrate its efficacy.

The Translational potential of this article

The results of this study indicate that this bioactive collagen scaffold has unique properties for supporting tendon growth and that it is non-immunogenic. The clinical study further confirms that the scaffold is a promising biological device for augment of human rotator cuff repairs.

Chitosan-Platelet-Rich Plasma Implants Improve Rotator Cuff Repair in a Large Animal Model: Pivotal Study

The purpose of this study was to assess the safety and efficacy of chitosan-platelet-rich plasma (PRP) hybrid implants used as an adjunct to surgical rotator cuff repair in a pivotal Good Laboratory Practice (GLP)-compliant study. The infraspinatus tendon was transected in 48 skeletally mature ewes and repaired with a transosseous-equivalent (TOE) technique. In the two treatment groups, a chitosan-PRP solution was injected at the footprint between the tendon and the bone and on top of the repaired site (2 mL or 3 mL doses, n = 12 per group). To further assess chitosan safety, a chitosan-water solution was injected at the same sites (3 mL, n = 12). Outcome measures included Magnetic Resonance Imaging (MRI) assessment and clinical pathology at 3 months and 6 months and histopathology at 6 months. The tendon gap was decreased at 3 months on MRI images and certain histopathological features were improved at 6 months by chitosan-PRP treatment compared to controls. The group treated with chitosan-water was not different from controls. Chitosan-PRP treatment induced no negative effects in the sheep, which suggests high safety. This study provides further evidence on the safety and efficacy of chitosan-PRP for rotator cuff repair augmentation, which could eventually be used in a clinical setting.