Scaffold- and graft-based biological augmentation of rotator cuff repair: an updated systematic review and meta-analysis of preclinical and clinical studies for 2010-2022

The bioinductive collagen implant yields positive histological, clinical and MRI outcomes in the management of rotator cuff tears: A systematic review

PURPOSE

The aim of this study is to report and discuss the outcomes of clinical, histological and animal studies exploring the application of bio-inductive collagen implants (BCIs) to partial and full-thickness rotator cuff tears (PT- and FT-RCTs) in addition to reporting on cost-related factors.

METHODS

Review of literature was performed using the PRISMA guidelines. A systematic electronic literature search was conducted using the CENTRAL, CINAHL, Cochrane Library, EBSCOhost, EMBASE and Google Scholar bibliographic databases. Microsoft Excel was used to create tables onto which extracted data were recorded. Tables were organized based on the research statement formulated using the PICO approach. No statistical analysis was performed.

RESULTS

Nine studies evaluated clinical and MRI outcomes of BCI augmentation for FT-RCTs, seven evaluated similar outcomes when applied to PT-RCTs, two additional studies were case reports and three studies assessed application to FT- and PT-RCTs without stratification of results, one of which also reported on histological data. Two studies reported on histological data alone, and finally, two reported on healthcare costs. BCI augmentation, alone and combined with rotator cuff repair (RCR), displays generally good histological, postoperative clinical and MRI outcomes for PT- and FT-RCT treatment. Recent economic analyses seem to be in favour of the use of this procedure, when selected and applied for appropriate patient populations.

CONCLUSION

Several studies have shown promising results of BCI application to PT- and FT-RCTs, both concomitantly and independently from RCR. Investigations report promising histological characteristics, improved clinical outcomes, increased tendon thickness, reduced defect size and lower re-tear rates.

LEVEL OF EVIDENCE

Level IV.

Bioaugmentation demonstrates similar outcomes and failure rates for arthroscopic revision rotator cuff repair compared to revision without bioaugmentation

Background

Arthroscopic revision rotator cuff repairs (RCRs) exhibit lower healing rates and inferior outcomes compared to primary repairs. There is limited evidence regarding the use of bioaugmentation in the setting of revision RCRs. Autologous conditioned plasma (ACP) is a promising adjunct that has been shown to improve healing rates and patient-reported outcomes (PROs) in the primary setting. In addition, bioinductive patches such as collagen bovine patches have become a popular adjunct for stimulating healing in the primary setting. The aim of this study is to assess the outcomes after use of ACP and collagen bovine patch augmentation for revision arthroscopic RCR. We hypothesized improved PROs and higher healing rates would be observed with bioaugmentation for revision repair compared to without.

Methods

This was an institutional review board-approved, retrospective case-control study from 2 fellowship-trained surgeons that included all consecutive patients undergoing arthroscopic revision RCR from 2010 to 2021. Reconstruction such as superior capsular reconstruction, partial revision repair, and less than 1-year follow-up were excluded. The bioaugmentation cohort received ACP and/or collagen bovine patch at the time of revision repair. PROs were collected from all patients including American Shoulder and Elbow Surgeons Standardized Assessment Form (ASES), visual analog scale for pain (VAS), Brophy score, and Patient-Reported Outcomes Measurement Information System (PROMIS) mental and physical scores. Failure of revision RCR was defined as an ASES postoperative total score less than 60 or a symptomatic retear confirmed on magnetic resonance imaging. Student's t-test was used for all comparisons of continuous variables. Chi-squared test used for comparison of all categorical variables. Statistical significance was set at <0.05.

Results

Thirty-eight patients met inclusion criteria with average follow-up of 3.5 ± 1.7 years. There was no significant difference in follow-up between patients with and without bioaugmentation. Of the 38 patients, 14 patients met failure criteria. There was no significant difference in the rate of failure between the bioaugmentation cohort (6/19, 31.6%) vs. patients who did not receive bioaugmentation (8/19, 42.1%) (P = .74). In addition, no significant differences were identified for ASES (64.6 ± 20.1 vs. 57.5 ± 17.2, P = .32), Brophy (6.4 ± 5.2 vs. 6.0 ± 4.1, P = .84), PROMIS Mental (13.4 ± 3.9 vs. 11.7 ± 3.2), or PROMIS Physical (12.8 ± 3.1 vs. 11.9 ± 3.2) scores between the bioaugmentation vs. no bioaugmentation groups.

Conclusion

Bioaugmentation with a bioinductive collagen patch or ACP demonstrated similar failure and PROs compared to without bioaugmentation in the setting of revision RCR.

An isolated bioinductive repair vs sutured repair for full-thickness rotator cuff tears: 2-year results of a double blinded, randomized controlled trial

BACKGROUND

Partial-thickness rotator cuff tears treated with an isolated bioinductive repair (IBR) in lieu of a completion-and-repair have shown complete healing. This treatment option is afforded by the remaining tendon's structural integrity, which is similar to that present in small/medium full-thickness tears (FTTs) when the rotator cable remains intact. This randomized controlled trial (RCT) investigated whether an IBR for small/medium full-thickness tears resulted in superior healing and patient-reported outcomes (PROs) compared with a sutured repair.

METHODS

This prospective, double blinded (patients and outcome assessors), single-center randomized controlled trial enrolled patients ≥18 years with a small/medium (≤2.5 cm) full thickness supraspinatus tear and intact rotator cable. Patients were randomized and blinded to arthroscopic transosseous-equivalent repair (control, n = 30) or IBR (n = 30). The primary outcome was tendon quality on biopsy at 6 months. Secondary outcomes were PROs (American Shoulder and Elbow Surgeons [ASES], Constant-Murley Shoulder [CMS], and pain visual analogue scale scores) and tendon thickness and healing measured via MRI at 6, 12, and 24 months; satisfaction at 12 and 24 months; and time to return to work.

RESULTS

Baseline demographic, tear, and surgical characteristics were comparable between the groups (IBR: mean age, 54.2 years, 14 male; control: mean age, 56.4 years, 16 male). Measured via a 6-month biopsy, highly organized, parallel bundles of collagen, without inflammation, were present in all IBR patients, whereas poorly organized, nonparallel collagen fibers were present in 24/30 (80%) of control patients (P < .0001), with 28/30 having minimal to mild inflammation. The increase in tendon thickness measured via MRI at 6 months from baseline was greater in the IBR group (2.0 mm) than in the control group (0.8 mm) (P < .0001). All IBR patients had 100% healing on MRI at 12 and 24 months. Compared with the control group, the IBR group had higher American Shoulder and Elbow Surgeons and Constant-Murley Shoulder scores at each evaluation, less pain at 6 and 12 months, and greater satisfaction at 12 and 24 months (P < .0003). The IBR group returned to work significantly faster (median 90 days [IQR, 25] vs. median 163.5 days [IQR, 24]; P < .0001) than the control group.

CONCLUSION

Compared with a sutured repair, the IBR treatment resulted in superior tendon quality, patient outcomes, satisfaction, and return to work. The IBR enabled a robust healing response evident through MRI and biopsy evaluation, demonstrating superior tendon quality and healing.

The addition of mesenchymal stem cells in a bioabsorbable scaffold does not enhance tendon healing after a repair of rotator cuff tear

PURPOSE

The purpose of the study is to evaluate the healing potential of a full-thickness tendon defect in the rotator cuff of rabbits using a bioabsorbable scaffold impregnated with bone marrow-mesenchymal stem cells (BM-MSCs) or rotator cuff-derived mesenchymal stem cells (RC-MSCs).

METHODS

Sixteen adult rabbits were subjected to a full-thickness rotator cuff deficit. Rabbits were randomly assigned to four groups of four animals. In Group 0 (control), the deficit was left untreated. In Group 1, the deficit was treated with a single synthetic scaffold alone. In Group 2, the deficit was treated with the previous scaffold loaded with allogeneic BM-MSCs. In Group 3, the deficit was treated with the previous scaffold loaded with allogenic RC-MSCs. After animal sacrifice, tissue samples were subjected to histological and immunohistochemical analysis.

RESULTS

Group 1 showed the highest mean tendon maturing score (15.3 ± 0.9) postoperatively, being significantly higher, in comparison to groups 0, 2 and 3 (p = 0.01, 0.02 and 0.01, respectively). Group 1 showed the highest mean collagen I/collagen III ratio (1.4 ± 0.8) postoperatively but without any statistical significance.

CONCLUSIONS

The utilization of MSCs in rotator cuff repair in a rabbit model has not been associated with an enhancement in tendon healing in 16 weeks postoperatively, in comparison to controls and bioabsorbable scaffolds. The addition of MSCs does not result in better rotator cuff healing.

LEVEL OF EVIDENCE

Not applicable. This is an animal study.

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.

Editorial Commentary: Health Care Policies Must Ensure Equitable Access for All Patients

It is critical to identify disparities in health care, including orthopaedic pathology, to ensure equitable care across all populations. Recent research shows that White, socially nondeprived, male patients with private insurance are more likely to undergo surgical procedures for rotator cuff disease after a minimum of 6 months of nonoperative management, and race and low income are associated with delays in access to health care and worse outcomes. Moreover, many practitioners and researchers do not record or report important socioeconomic factors. Health care policies must ensure equitable access for all patients, and physicians and other providers must proactively identify patients at risk in order to optimize care.

Editorial Commentary: Bioinductive Collagen Implants Reduce Rotator Cuff Retear, yet Cost-Effectiveness and Improvement in Clinical Outcomes Are Unclear

The estimated health care costs of failed arthroscopic rotator cuff retears (RCRs) performed in the United States represent a huge economic burden of greater than $400 million per 2-year period. Unfortunately, retear rates do not appear to have improved significantly since the 1980s, despite advances in surgical technology and the biomechanics of repair. The failure of these advances to translate into improved clinical results suggests that the limiting step in reducing retear rates is biology rather than the biomechanics of repair. Bioinductive collagen implants (BCIs) are an emerging and potentially useful option for biological augmentation. Recent meta-analysis of preclinical and clinical studies demonstrates that biological augmentation significantly lowers the risk of retear. Retrieval studies from human RCR subjects who underwent treatment with BCI demonstrate cellular incorporation, tissue formation, and maturation, providing a logical basis for a reduction in retear rates as well as small increases in tendon thickness at the footprint. Although BCIs show potential as a possible game-changing solution for reducing failure rates of RCR, concerns remain regarding cost-effectiveness analyses and demonstration of functional outcome improvement.

Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BACKGROUND

Rotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.

METHODS

Twenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.

RESULTS

At 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.

CONCLUSION

Our study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Acellular Collagen Matrix Patch Augmentation of Arthroscopic Rotator Cuff Repair Reduces Re-Tear Rates: A Meta-analysis of Randomized Control Trials

PURPOSE

To perform a meta-analysis of randomized controlled trials (RCTs) to compare the outcomes of arthroscopic rotator cuff repair (ARCR) with and without acellular collagen matrix patch (ACMP) augmentation.

METHODS

A literature search of 3 databases was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RCTs comparing ACMP augmentation and a control for ARCR were included. Clinical outcomes were compared using Revman, and a P value < .05 was considered to be statistically significant.

RESULTS

Five RCTs with 307 patients were included. Overall, 11% of patients treated with ACMP augmentation and 34% of patients in the control group had a re-tear (P = .0006). The mean Constant score was 90.1 with ACMP augmentation, and 87.3 in controls (P = .02). Additionally, there was a significant higher American Shoulder and Elbow Surgeons score with ACMP augmentation (87.7 vs 82.1, P = .01).

CONCLUSIONS

The RCTs in the literature support the use of ACMP augment as a modality to reduce re-tear rates and improve outcomes after ARCR.

LEVEL OF EVIDENCE

Level II, Meta-Analysis of Level II Studies meta-analysis of Level II studies.

From Conservative Measures to Surgical Interventions, Treatment Approaches for Cubital Tunnel Syndrome: A Comprehensive Review

Cubital tunnel syndrome (CuTS) is a neuropathic condition characterized by the compression or irritation of the ulnar nerve at the elbow, resulting in a wide spectrum of symptoms ranging from pain and numbness to muscle weakness and impaired hand function. This comprehensive review delves into the diverse landscape of CuTS treatment approaches, emphasizing the importance of early intervention. The review explores how these strategies aim to alleviate symptoms and enhance patient well-being by beginning with conservative measures encompassing rest, splinting, medications, physical therapy, and lifestyle adjustments. Non-surgical medical interventions, including nerve gliding exercises, ultrasound-guided nerve injections, and orthotic devices, are considered alternative therapies for symptom relief. Surgical interventions, such as decompression procedures and emerging techniques, are discussed in detail, highlighting their indications and expected outcomes. Throughout this review, the critical role of patient-centered care is underscored, emphasizing the need for tailored treatment plans that respect individual preferences and goals. Recognizing the unique nature of each CuTS case, shared decision-making between patients and healthcare providers is advocated, ensuring that interventions align with specific patient needs. As research advances, promising developments in diagnosis, surgical techniques, and drug therapies offer hope for more effective management of CuTS, paving the way for improved symptom relief and enhanced nerve function.