Porcine small intestine submucosa augmentation of surgical repair of chronic two-tendon rotator cuff tears. A randomized, controlled trial

Nanofiber Scaffolds by Electrospinning for Rotator Cuff Tissue Engineering

Rotator cuff tears continue to be at risk of retear or failure to heal after surgical repair, despite the use of various surgical techniques, which stimulate development of novel scaffolding strategies. They should be able to address the known causes of failure after the conventional rotator cuff repair: (1) failure to reproduce the normal tendon healing process, (2) resultant failure to reproduce four zones of the enthesis, and (3) failure to attain sufficient mechanical strength after repair. Nanofiber scaffolds are suited for this application because they can be engineered to mimic the ultrastructure and properties of the native rotator cuff tendon. Among various methods for tissue-engineered nanofibers, electrospinning has recently been highlighted in the rotator cuff field. Electrospinning can create fibrous and porous structures that resemble natural tendon's extracellular matrix. Other advantages include the ability to create relatively large surface-to-volume ratios, the ability to control fiber size from the micro to the nano scale, and the flexibility of material choices. In this review, we will discuss the anatomical and mechanical features of the rotator cuff tendon, their potential impacts on improper healing after repair, and the current knowledge of the use of electrospinning for rotator cuff tissue engineering.

Use of implantable meshes for augmented rotator cuff repair: a systematic review and meta-analysis

OBJECTIVE

To appraise studies reporting on clinical effectiveness and safety of surgical meshes used to augment rotator cuff repairs (RCRs).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase and Cochrane databases were searched between April 2006 and April 2020.

ELIGIBILITY CRITERIA

All studies evaluating adults (≥18 years) undergoing RCR were considered. There were no language restrictions.

DATA EXTRACTION AND SYNTHESIS

Screening, data extraction and quality appraisal were conducted by two independent reviewers. Meta-analysis was conducted using a random-effects models if ≥2 comparative studies reported the same outcome measure. Risk of bias assessment was undertaken for randomised (RoB2, Cochrane) and comparative studies (ROBINS-I, Cochrane).

RESULTS

We included 60 studies, consisting of 7 randomised controlled trials, 13 observational comparative studies and 40 observational case series. All comparative studies reported on shoulder-specific functional outcome scores, 18 on the radiographic occurrence of re-tear and 14 on pain score metrics. All studies contained some risk of bias.Compared with non-augmented repair, a small improvement in shoulder-specific function or pain scores was observed for synthetic patches with a mean improvement of 6.7 points on the University of California Los Angles (UCLA) shoulder score (95% CI 0.1 to 13.4) and 0.46 point reduction on the Visual Analogue Scale (95% CI -0.74 to -0.17), respectively. A reduced likelihood of radiologically observed re-tear was observed for synthetic (risk ratio (RR) 0.41, 95% CI 0.27 to 0.61) and allograft (RR 0.34, 95% CI 0.18 to 0.65) patches. A total of 49 studies reported on the occurrence of complications. Slightly higher crude complication rates were observed following patch-augmented repair (2.1%) than standard repair (1.6%).

CONCLUSIONS

While several studies suggest a decreased failure rate and small improvements in shoulder function and pain following augmented RCR, a paucity of rigorous clinical evaluation, for both effectiveness and safety, prevents firm recommendations.

PROSPERO REGISTRATION NUMBER

CRD42017057908.

Biologics to Improve Healing in Large and Massive Rotator Cuff Tears: A Critical Review

Large and massive rotator cuff tears have the highest risk of retear. Common biologic modalities that can potentially reduce the retear rate and improve healing include platelet-rich plasma (PRP), scaffolds, and mesenchymal stem cells (MSCs). PRP has been studied for its role in improving rotator cuff healing and results of randomized controlled trials and meta-analyses show mixed results. Most studies in large and massivge tears show that PRP decreases the retear rate, but the connection between structural integrity and clinical outcomes is still unknown. Extracellular matrix (ECM) and synthetic scaffolds can increase healing in augmentation and bridging repair. Acellular dermal allografts have shown better healing rates and outcomes than xenografts in meta-analyses. Synthetic scaffolds augmented with bone marrow-derived stem cells have only been studied in vitro but are promising for the combination of mechanical stability and induction of a biological response. Superior capsule reconstruction is an exciting type of interposition graft reconstruction that has shown favorable early clinical outcomes for large and massive tears. Bone marrow-derived stem cells and adipose-derived stem cells improve the biomechanical characteristics of tendon repair and enhance the histological findings of the healing process in animal studies. However, evidence from human studies is lacking, especially in patients with large and massive tears. In summary, there are many biological options to augment rotator cuff repair in patients with large and massive tears. Due to mixed results and a lack of standardization in high-quality studies, we cannot recommend PRP at this time as an adjunct to rotator cuff repair. Both ECM and synthetic scaffolds, as well as SCR, can be used, especially in situations where native tendon is compromised, and additional mechanical augmentation is needed. Stem cells have been the least studied to date, so it is difficult to give recommendations for or against their use at this time.

Biomechanical Comparison of Augmentation of Engineered Tendon-Fibrocartilage-Bone Composite With Acellular Dermal Graft Using Double Rip-Stop Technique for Canine Rotator Cuff Repair

Background

The retear rate after rotator cuff repair remains unacceptably high. Various biological engineered scaffolds have been proposed to reduce the retear rate. We have developed a double rip-stop repair with medial row knot (DRSK) technique to enhance suture-tendon strength and a novel engineered tendon-fibrocartilage-bone composite (TFBC) for rotator cuff repair.

Hypothesis

DRSK rotator cuff repair augmented with TFBC will have better biomechanical properties than that of DRSK repair with an acellular dermal graft (DG).

Study Design

Controlled laboratory study.

Methods

Fresh-frozen canine shoulders (n = 30) and knees (n = 10) were used. TFBCs were harvested from the patellar tendon-tibia complex and prepared for rotator cuff repair. The infraspinatus tendon was sharply detached from its bony attachment and randomly assigned to the (1) control group: DRSK repair alone, (2) TFBC group: DRSK repair with TFBC, and (3) DG group: DRSK repair with DG. All specimens were tested to failure, and videos were recorded. The footprint area, tendon thickness, load to create 3-mm gap formation, failure load, failure modes, and stiffness were recorded and compared. Data were recorded as mean ± SD.

Results

The mean load to create a 3-mm gap in both the control group (206.8 ± 55.7 N) and TFBC group (208.9 ± 39.1 N) was significantly higher than that in the DG group (157.7 ± 52.3 N) (P < .05 for all). The failure load of the control group (275.7 ± 75.0 N) and TFBC group (275.2 ± 52.5 N) was significantly higher compared with the DG group (201.5 ± 49.7 N) (P < .05 for both comparisons). The stiffness of the control group (26.4 ± 4.7 N/mm) was significantly higher than of the TFBC group (20.4 ± 4.4 N/mm) and the DG group (21.1 ± 4.8 N/mm) (P < .05 for both comparisons).

Conclusion

TFBC augmentation showed superior biomechanical performance to DG augmentation in rotator cuff tears repaired using the DRSK technique, while there was no difference between the TFBC and control groups.

Clinical Relevance

TFBC may help to reduce retear or gap formation after rotator cuff repair using the DRSK technique.

A Historical Analysis of Randomized Controlled Trials in Rotator Cuff Tears

Background and objectives: Our research aimed to evaluate the quality of reporting of randomized controlled trials (RCTs) linked to rotator cuff (RC) tears. The present study analyzed factors connected to the quality of the RCTs and trends in the quality of reporting through time. Materials and Methods: The online databases used to search all RCTs on the topic of RC surgery completed until March 2020 were PubMed and Ovid (MEDLINE). The quality of reporting was evaluated using the modified Coleman methodology score (MCMS) and the consolidated standards of reporting trials (CONSORT). Results: The online search found 957 articles. Finally, 183 studies were included in the quantitative synthesis. A total of 97 (53%) of 183 studies had a level of evidence I and 86 (47%) of 183 studies had a level of evidence II, according to the Oxford Center of Evidence Based Medicine (EBM). A statistically significant difference in MCMS between articles written before 2010 and articles written after 2010 was found. Articles written after 2010 had, on average, the highest Coleman score. The average number of CONSORT checklist items for each article across all analyzed RCTs was 21.67. The 37 studies completed up to 2010 averaged a number of checklist items of 19.97 and the studies completed between 2011 and 2019 averaged a number of checklist items of 22.10. A statistically significant difference in the number of checklist items between articles written before 2010 and articles written after 2010 was found. Articles written after 2010 had on average more checklist items. However, low correlation (0.26) between the number of checklist items for each article and the respective Coleman score was found. On the other hand, articles with the CONSORT diagram had a significantly high Coleman score. Conclusions: An improvement in the quantity and quality of RCTs relating to RC surgery over the analyzed period was found.

Variability of glenohumeral positioning and bone-to-tendon marker length measurements in repaired rotator cuffs from longitudinal computed tomographic imaging

Background

To address the need for more objective and quantitative measures of tendon healing in research studies, we intend to use computed tomography (CT) with implanted radiopaque markers on the repaired tendon to measure tendon retraction following rotator cuff repair. In our small prior study, retraction at 1-year follow-up averaged 16.1± 5.3 mm and exceeded 10.0 mm in 12 of 13 patients, and thus tendon retraction appears to be a common clinical phenomenon. This study's objectives were to assess, using 5 longitudinal CT scans obtained over 1 year following rotator cuff repair, the variability in glenohumeral positioning because of pragmatic variations in achieving perfect arm repositioning and to estimate the associated measurement variability in bone-to-tendon marker length measurements.

Methods

Forty-eight patients underwent rotator cuff repair with intraoperative placement of radiopaque tendon markers at the repair site. All patients had a CT scan with their arms at the side on the day of surgery and at 3, 12, 26, and 52 weeks postoperatively. Glenohumeral position (defined by the orientation and distance of the humerus with respect to the scapula) and bone-to-tendon marker lengths were measured from each scan. Within-patient variation in glenohumeral position measurements was described by their pooled within-patient standard deviations (SDs), and variation in bone-to-tendon marker lengths by their standard errors of measurement (SEMs) and 95% confidence level minimally detectable distances (MDD₉₅) and changes (MDC₉₅).

Results

The mean glenohumeral orientation from the 5 longitudinal CT scans averaged across the 48 patients was 12.6° abduction, 0.4° flexion, and –0.1° internal rotation. Within-patient SDs (95% confidence intervals) of glenohumeral orientation were 3.0° (2.7°-3.4°) in extension/flexion, 5.2° (4.6°-5.8°) in abduction/adduction, and 8.2° (7.3°-9.2°) in internal/external rotation. The SDs of glenohumeral distances were less than 1 mm in any direction. The estimated SEMs of bone-to-tendon lengths were consistent with a common value of 2.4 mm for any of the tendon markers placed across the repair, with MDD₉₅ of 4.7 mm and MDC₉₅ of 6.7 mm.

Conclusion

Apparent tendon retraction of 5 mm or more, when measured as the distance from a tendon marker's day of surgery location to its new location on a volumetrically registered longitudinal CT scan, may be considered above the usual range of measurement variation. Tendon retraction measured using implanted radiopaque tendon markers offers an objective and sufficiently reliable means for quantifying the commonly expected changes in structural healing following rotator cuff repair.

Arthroscopic repair of posterosuperior rotator cuff tears with bioabsorbable patch augmentation: a magnetic resonance-controlled case series with 1-year follow-up

Background

Among many advances in the treatment of rotator cuff tears, arthroscopic augmentation techniques with patches of various biological and synthetic graft materials have been introduced to reinforce the repair. However, structural and functional outcomes after patch augmentation vary, and reinforcing the tendon healing remains a challenge. The aim of this study was to evaluate clinical and radiologic outcomes 1 year after arthroscopic posterosuperior (PS) rotator cuff repair with bioabsorbable patch augmentation.

Methods

From October 2014 to December 2017, all patients with PS rotator cuff tears undergoing arthroscopic repair with patch augmentation using a resorbable, biologically derived poly-4-hydroxybutyrate patch (Biofiber; Wright, Memphis, TN, USA) were enrolled in this study. Only full-thickness PS lesions with ≥1 of the following tear patterns were augmented with a patch and were the subject of this study: large U- and L-shaped tear, transtendinous tear, delamination, and fraying of the bursal layer. Patients were examined preoperatively and at 1 year postoperatively with a standardized examination protocol and magnetic resonance imaging (MRI).

Results

Sixteen patients were included in this study; 1 patient was lost to follow-up. One patient only underwent clinical follow-up. We detected 1 repair failure (6.7%) with dislocation of the lateral-row anchors on computed tomography scanning at 3 months postoperatively. MRI was performed in 14 patients after 1 year; in all of them, the cuff repair was intact. The Sugaya tendon integrity score was 1.7 ± 0.9. The Constant-Murley score improved from 44 to 89 points (P < .001). Muscular strength improved in the supraspinatus (from 2.6 to 4.8), infraspinatus (from 3.2 to 4.9), and subscapularis (from 4 to 4.9) (all P < .001). Overall, patient satisfaction was high (3.6 ± 0.6).

Discussion

This small-sized case series is the first to prospectively assess clinical and radiologic outcomes after patch augmentation of PS rotator cuff tears using bioabsorbable poly-4-hydroxybutyrate patches. Good to excellent structural and functional outcomes were observed with a low retear rate (6.7%) and good tendon integrity on 1-year postoperative MRI, and the graft did not cause any complications. The use of bioabsorbable patches could be beneficial when unfavorable PS tear patterns are encountered in which a stable repair of the full tendon thickness at its insertion is otherwise difficult to reach.

Superior capsular reconstruction: 2-year follow-up results

Introduction

A prerequisite for a satisfying functional result in the treatment of an irreparable rotator cuff rupture is a significant reduction of shoulder pain and better range of motion with an increase in anatomic glenohumeral joint stability.

Purpose

Prospective study to examine the outcome after superior capsular reconstruction using a porcine extracellular matrix dermal graft. A special emphasis was primarily on the functional outcome, secondarily on radiographic shoulder changes, that superior capsular reconstruction might yield.

Methods

Clinical results were evaluated using the Constant score and Western Ontario Rotator Cuff (WORC) index over a 2-year period. All patients had magnetic resonance imaging (MRI) of the injured shoulder after 1 year. Graft integration and durability were qualitatively estimated as well as any graft deterioration or resorption.

Results

Thirteen patients with 13 superior capsular reconstructions were included over a 3-year period. Mean age was 61 years (range 50-70) at the time of surgery. At final follow-up (mean 24 months, range 23-32), the mean Constant score had improved from an average of 24.9-55.7 points. The mean WORC index had increased from a percentage average of 32.3%-61.9%. Eleven of 13 grafts were intact on follow-up MRI.

Conclusion

Our hypothesis was that successful implantation of a dermal xenograft would correlate with both better functional outcome and stabilized glenohumeral radiographic features. We saw a group of patients with variable but significant increases in functional results and in general with limited pain and with an intact xenograft on an MRI scan. We did not find a positive correlation between functional outcome scores and graft durability nor with single cuff tendon defects vs. larger rotator cuff defects.This study suggests that a superior capsular reconstruction can yield results that are comparable or superior to other known salvage treatment options in patients with large to massive rotator cuff defects without significant cuff tear arthropathy. The hypothesis that superior capsular reconstruction can be a relevant treatment method for irreparable rotator cuff tears could not be refuted despite a fairly low patient inclusion number. With these results, selected patients can be considered for a different treatment than reverse shoulder arthroplasty, débridement, or tendon transfer.

Comparison Between Autografts and Allografts in Superior Capsular Reconstruction: A Systematic Review of Outcomes

BACKGROUND

The treatment of irreparable rotator cuff tears (IRCTs) is a significant challenge, and various treatment options have emerged. Superior capsular reconstruction (SCR) is a promising procedure for patients with IRCTs.

PURPOSE

To investigate the clinical outcomes of SCR and compare allografts with autografts.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search for relevant articles was carried out using the PubMed, Cochrane Library, Embase, Scopus, and Google Scholar databases. We used medical subject heading (MeSH) terms and natural keywords (superior AND (capsule OR capsular) AND reconstruction). Also, we filtered for high-quality articles using the Methodological Index for Non-Randomized Studies (MINORS). We summarized the characteristic data and commonly used outcome measures of each included study and performed a descriptive analysis using an evidence-based tendency concept as proposed by Huisstede et al (2013).

RESULTS

A total of 10 articles (374 shoulders) with a mean follow-up of 27.2 months were selected and analyzed. There were 4 articles on SCR with an autograft, 4 on SCR with an allograft, and 2 on SCR with both an autograft and allograft. For autografts and allografts, respectively, the mean gain in forward elevation (FE) was 48.7° and 33.3°, the visual analog scale for pain score improved by 3.5 and 3.3, the American Shoulder and Elbow Surgeons (ASES) score increased by 47.3 and 31.9, and the acromiohumeral distance increased by 1.2 and 1.8 mm. In addition, the number of graft tears was 16 (10.0%) and 17 (12.9%), the number of other complications was 12 (7.5%) and 6 (3.9%), and the number of reoperations was 5 (3.1%) and 14 (8.2%) for autografts and allografts, respectively.

CONCLUSION

Both autografts and allografts improved clinical outcomes. Although the graft tear rate appeared similar between the autograft and allograft groups, the autograft group had no cases of conversion to reverse total shoulder arthroplasty. In addition, we found 3 evidence-based tendencies: (1) a tendency for both autografts and allografts to have significantly improved FE and clinical scores, (2) a tendency that autografts improved internal rotation and allografts improved abduction, and (3) a weak tendency that autografts improved abduction and allografts improved internal and external rotation. Although it was not possible to compare the groups statistically, the differences in ASES scores might be clinically important and will need to be explored in future comparative studies.

Augmenting endogenous repair of soft tissues with nanofibre scaffolds

As our ability to engineer nanoscale materials has developed we can now influence endogenous cellular processes with increasing precision. Consequently, the use of biomaterials to induce and guide the repair and regeneration of tissues is a rapidly developing area. This review focuses on soft tissue engineering, it will discuss the types of biomaterial scaffolds available before exploring physical, chemical and biological modifications to synthetic scaffolds. We will consider how these properties, in combination, can provide a precise design process, with the potential to meet the requirements of the injured and diseased soft tissue niche. Finally, we frame our discussions within clinical trial design and the regulatory framework, the consideration of which is fundamental to the successful translation of new biomaterials.

Scaffolds in the management of massive rotator cuff tears: current concepts and literature review

Injuries to the rotator cuff (RC) are common and could alter shoulder kinematics leading to arthritis. Synthetic and biological scaffolds are increasingly being used to bridge gaps, augment RC repair and enhance healing potential. Our review evaluates the clinical applications, safety and outcome following the use of scaffolds in massive RC repair.

A search was performed using EBSCO-Hosted Medline, CINAHL, Cochrane and PubMed using various combinations of the keywords ‘rotator cuff’, ‘scaffold’, ‘biological scaffold’, ‘massive rotator cuff tear’ ‘superior capsular reconstruction’ and ‘synthetic scaffold’ between 1966 and April 2018. The studies that were most relevant to the research question were selected. All articles relevant to the subject were retrieved, and their bibliographies hand searched.

Synthetic, biosynthetic and biological scaffolds are increasingly being used for the repair/reconstruction of the rotator cuff. Allografts and synthetic grafts have revealed more promising biomechanical and early clinical results than xenografts. The retear rates and local inflammatory reactions were alarmingly high in earlier xenografts. However, this trend has reduced considerably with newer versions. Synthetic patches have shown lower retear rates and better functional outcome than xenografts and control groups.

The use of scaffolds in the treatment of rotator cuff tear continues to progress. Analysis of the current literature supports the use of allografts and synthetic grafts in the repair of massive cuff tears in reducing the retear rate and to provide good functional outcome. Though earlier xenografts have been fraught with complications, results from newer ones are promising. Prospective randomized controlled trials from independent centres are needed before widespread use can be recommended.

Cite this article: EFORT Open Rev 2019;4:557-566. DOI: 10.1302/2058-5241.4.180040

Adverse effects of xenogenic scaffolding in the context of a randomized double-blind placebo-controlled study for repairing full-thickness rotator cuff tears

PURPOSE

The purpose of the study was to compare the safety and efficacy of autologous mesenchymal stem cells (MSCs) embedded in a xenogenic scaffold for repairing the supraspinatus tendon.

METHODS

This was a randomized, double-blind and placebo-controlled trial evaluating patients with full-thickness rotator cuff tears (Eudra-CT, 2007-007630-19). Effectiveness was evaluated using the Constant score and a visual analogue pain scale (VAS). Constant score has four domains including pain (15 possible points), activities of daily living (20 possible points), mobility (40 possible points), and strength (25 possible points). Scores range from 0 points (most disability) to 100 points (least disability). The structural integrity of the repaired tendon was assessed by magnetic resonance imaging (MRI) according to Patte and Thomazeau classification criteria. The primary study end point was an improvement in the Constant score by 20 points at one year compared to initial assessment.

RESULTS

The trial was stopped due to adverse effects observed in both groups. Only thirteen patients were included and analyzed. The Constant questionnaire showed a significant improvement in the MSC treatment group compared with the preoperative data (p = 0.0073). Secondary outcome measures were similar in both groups.

CONCLUSIONS

Our study showed preliminary inconclusive clinical outcomes in the patients treated with MSCs. Adverse events revealed the need for further approaches using scaffolds of a different nature or perhaps no scaffolds, in the context of small joints.

TRIAL REGISTRATION

Eudra-CT, 2007-007630-19 . Registered on 30 January 2008.

LEVEL OF EVIDENCE

A Level 1 of evidence treatment study.

Rationale for Biologic Augmentation of Rotator Cuff Repairs

The structural integrity of rotator cuff repair (RCR) has been a primary focus for shoulder surgeons seeking long-term clinical and functional success. Improvements in surgical techniques have allowed for superior initial biomechanical fixation. However, tendon healing remains a significant clinical problem even after rigid time-zero repair. The lack of long-term healing has led to increased interest in biologic augmentation to improve tendon-to-bone healing. This interest has led to a rise in the investigation of small molecular therapies, cell-based strategies, and tissue-derived treatments offering surgeons a new therapeutic toolbox for potentially improving RCR long-term outcomes. However, the delivery, efficacy, and safety of these treatments remain under investigation. Additional well-designed, high-level studies are of paramount importance in creating evidence-based guidelines for the implementation of new biologic solutions. This review article discusses the current preclinical, translational, and clinical experience with and rationale for biologic augmentation in RCR.

Use of a Novel, Reinforced, Low Immunogenic, Porcine Small Intestine Submucosa Patch to Repair a Supraspinatus Tendon Defect in a Rabbit Model

Background

Repairs of large to massive rotator cuff tears have a high failure rate. We investigated the efficacy of a novel, reinforced, low immunogenic, porcine small intestine submucosa (SIS) patch to repair a supraspinatus tendon defect in a rabbit model. We hypothesized that the histological and biomechanical results of SIS patch repair would be comparable with those of autologous fascia lata (FL) repair.

Methods

The study mainly comprised two parts. First, the characteristics of the SIS patch were evaluated, including its micromorphology, mechanical properties, and immunogenic properties. Second, a supraspinatus tendon defect model was created in 36 rabbits (72 shoulders). The bilateral shoulders were randomly chosen to undergo repair using either a SIS patch (SIS group) or autologous FL (FL group). At 4, 8, and 12 weeks, histological analysis was performed using four shoulders from each group, and biomechanical tests were performed using eight shoulders from each group.

Results

The SIS patch was a three-dimensional construct mainly composed of collagen fibers. The mean single and double suture retention loads of the SIS patch were 48.6 ± 5.8 N and 117.9 ± 2.7 N, respectively. The DNA content in the SIS patch was 53.9 ± 10.9 ng/mg dry weight. Both the histological score and ultimate load to failure increased in a time-dependent manner in both groups, with no significant differences between the SIS and FL groups at 12 weeks.

Conclusion

Repair of a large supraspinatus tendon defect using a reinforced, low immunogenic, SIS patch achieves similar effects as autologous FL in a rabbit model. This novel patch might be useful to be employed as a structural tissue replacement in medical activities.

Overlay repair with a synthetic collagen scaffold improves the quality of healing in a rat rotator cuff repair model

BACKGROUND

Augmenting repairs with extracellular matrix-based scaffolds is a common option for rotator cuff tears. In this study, a new collagen scaffold was assessed for its efficacy in augmenting rotator cuff repair.

METHODS

The collagen scaffold was assessed in vitro for cytocompatibility and retention of tenocyte phenotype using alamarBlue assays, fluorescent imaging, and real-time polymerase chain reaction. Immunogenicity was assessed in vitro by the activation of human monocytes. In vivo, by use of a modified rat rotator cuff defect model, supraspinatus tendon repairs were carried out in 40 animals. Overlay augmentation with the collagen scaffold was compared with unaugmented repairs. At 6 and 12 weeks postoperatively, the repairs were tested biomechanically to evaluate repair strength, as well as histologically to assess quality of healing.

RESULTS

The collagen scaffold supported human tendon-derived cell growth in vitro, with cells demonstrating proliferation and appearing morphologically tenocytic over the experimental period. No immunogenic responses were provoked compared with suture material control. In vivo, augmentation with the scaffold improved the histologic scores at 12 weeks (8.4 of 15 vs 6.4 of 15, P = .032). However, no significant difference was detected with mechanical testing.

CONCLUSION

The new collagen scaffold was supportive of cell growth in vitro and generated a minimal acute inflammatory response. In vivo, we observed an improvement in the histologic appearance of the repair at 12 weeks. However, a meaningful increase in biomechanical strength was not achieved. Further modification and improvement of the scaffold are required prior to consideration for clinical use.

Evaluating strategies and outcomes following rotator cuff tears

INTRODUCTION

Rotator cuff tear surgical repair techniques have significantly progressed. However, tendon retear following primary repair persistently occurs at high rates. Rehabilitation protocols, surgical fixation techniques, biologic therapy with scaffolds, platelet-rich plasma, and even stem cell applications are under study to promote adequate tendon healing.

METHODS

A nonsystematic query of the PubMed database was conducted in July 2016 utilizing the search terms "rotator cuff repair," "tear," "rehabilitation," "scaffold," "platelet-rich plasma," and "stem cell" to identify, analyze, and summarize relevant studies.

CONCLUSION

Individualized rehabilitation protocols may be the best approach for small to medium sized tears. Surgical fixation will continue to be debated as modifications to single-row technique and increases in suture number have improved tensile strength. Double-row repairs have been associated with higher costs. Transosseous equivalent technique exhibits comparable subjective and objective outcomes to single- and double-row repair at two-year follow-up. Biocompatible scaffold augmentation has showed inconsistent short-term results. Platelet-rich plasma has lacked uniformity in treatment preparation, administration, and outcome measurement with mixed results. Few human studies have suggested decreased retear rates and improved repair maintenance following bone marrow-derived mesenchymal stem cell augmentation. This review reiterated the necessity of additional high-quality, large-sample studies to develop any final verdict regarding efficacy.

Bridge-Enhanced Anterior Cruciate Ligament Repair: Two-Year Results of a First-in-Human Study

Background

Bridge-enhanced anterior cruciate ligament repair (BEAR) combines suture repair of the anterior cruciate ligament (ACL) with a specific extracellular matrix scaffold (the BEAR scaffold) that is placed in the gap between the torn ends of the ACL to facilitate ligament healing.

Purpose/Hypothesis

The purpose of this study was to report the 12- and 24-month outcomes of patients who underwent the BEAR procedure compared with a nonrandomized concurrent control group who underwent ACL reconstruction (ACLR) with an autograft. We hypothesized that the BEAR group would have physical examination findings, patient-reported outcomes, and adverse events that were similar to those of the ACLR group.

Study Design

Cohort study; Level of evidence, 2.

Methods

Ten patients underwent BEAR, and 10 underwent ACLR with a 4-stranded hamstring autograft. At 24 months, 9 of the 10 BEAR patients and 7 of the 10 ACLR patients completed a study visit. Outcomes reported included International Knee Documentation Committee (IKDC) subjective and objective results, knee anteroposterior (AP) laxity findings via an arthrometer, and functional outcomes.

Results

There were no graft or repair failures in the first 24 months after surgery. The IKDC subjective scores in both groups improved significantly from baseline (P < .0001) at 12 and 24 months, to 84.6 ± 17.2 in the ACLR group and to 91.7 ± 11.7 in the BEAR group. An IKDC objective grade of A (normal) was found in 44% of patients in the BEAR group and in 29% of patients in the ACLR group at 24 months; no patients in either group had C (abnormal) or D (severely abnormal) grades. Arthrometer testing demonstrated mean side-to-side differences in AP laxity that were similar in the 2 groups at 24 months (BEAR, 1.94 ± 2.08 mm; ACLR, 3.14 ± 2.66 mm). Functional hop testing results were similar in the 2 groups at 12 and 24 months after surgery. Hamstring strength indices were significantly higher in the BEAR group compared with the ACLR group (P = .0001).

Conclusion

In this small, first-in-human study, BEAR produced similar outcomes to ACLR with a hamstring autograft. BEAR may result in knee stability and patient-reported outcomes at 2 years sufficient to warrant longer term studies of efficacy in larger groups of patients.

Achilles Tendon Augmented Repair Using Human Acellular Dermal Matrix: A Case Series

Achilles tendon ruptures are common in the general population, especially among members of the older demographic occasionally active in sports. Operative treatments provide a lower incidence of rerupture than do nonoperative treatments, although surgical complications remain a concern. The use of a human acellular dermal matrix to augment Achilles tendon repair might reduce the incidence of complications. In the present case series, we describe the outcomes of 9 patients who underwent Achilles tendon repair with acellular dermal matrix augmentation. Functional outcomes were evaluated using the Foot Function Index-Revised long form, and the clinical results were recorded. After a mean average follow-up period of 14.4 (range 12.0 to 20.0) months, the mean Foot Function Index-Revised long form score was 33.0% ± 4.2%. No cases of rerupture or complications that required additional treatment occurred during the observation period. The outcomes we have presented support further evaluation beyond this case series for using a human acellular dermal matrix to augment Achilles tendon repairs.

Graft tears after arthroscopic superior capsule reconstruction (ASCR): pattern of failure and its correlation with clinical outcome

INTRODUCTION

Arthroscopic superior capsule reconstruction (ASCR) using fascia lata autograft is a new surgical technique developed to overcome irreparable rotator cuff tears. There is little information about graft tear after ASCR and its impact on clinical outcome. This study is to investigate the graft tear rate, pattern of failure, and its correlation with clinical outcomes after arthroscopic superior capsule reconstruction (ASCR).

MATERIALS AND METHODS

From June 2013 to June 2016, 31 shoulders in 31 consecutive patients (mean 65.3 years) underwent ASCR using fascia lata autograft for irreparable large-to-massive tears. Magnetic resonance imaging (MRI) was performed before surgery and at mean 12.8 months (12-24 months) after surgery to assess fatty infiltration progression and graft integrity. Graft tear was defined as the loss of graft continuity and was categorized as medial and lateral rows according to the failure location. Acromiohumeral distance (AHD) was pre- and postoperatively measured with the standard radiograph. Pain visual analog scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, constant score, and physical examination were used to assess clinical outcomes. Average follow-up was 15 months (range 12-24 months) after surgery.

RESULTS

Mean active forward elevation increased from 133° to 146° (P = 0.011). Mean VAS score, ASES score, and constant score significantly improved: from 6 to 2.5, 54.4 to 73.7, and 51.7 to 63.7, respectively (P < 0.001). There was no remarkable progression of fatty infiltration after surgery. AHD increased from 5.3 mm preoperatively to 6.4 mm postoperatively (P < 0.016). Nine patients (29%) showed graft tear on follow-up MRI: 7 and 2 at the medial and lateral rows, respectively. Although the intact graft group showed better outcomes than the graft tear group (pain VAS score 2.3 vs. 3.0; ASES score 74.1 vs. 69.8; constant score 63.4 vs. 57.9), the results were not statistically significant.

CONCLUSIONS

Graft tear rate after ASCR assessed by MRI was 29%, and failures mostly occurred at the medial row. The graft tear group showed clinical improvement despite the recurred superior capsule defect.

LEVEL OF EVIDENCE

IV, case series, treatment study.

Minimally invasive fascia lata harvesting in ASCR does not produce significant donor site morbidity

PURPOSE

The aim of this study was to prospectively evaluate donor site morbidity in arthroscopic superior capsular reconstruction using a minimally invasive harvested fascia lata autograft.

METHODS

Fifteen consecutive patients underwent arthroscopic superior capsular reconstruction by the senior author using a fascia lata autograft harvested in a minimally invasive fashion. All patients were prospectively evaluated at 1 week, 6 and 18 months postoperatively. The subjects' body mass index, age, actual or previous corticosteroid therapy history and active smoking habits were evaluated. Functional outcomes were assessed by the non-arthritic hip score applied to the harvested and contralateral thighs. Every patient completed standardized subjective satisfaction questionnaires at all evaluations. The median patient age was 65.5 years (range 47-77). Nine patients (60%) were females, and six (40%) were males. One patient (6.7%) was within the normal range of weight, nine (60%) were overweight, four (27%) were obese, and one (6.7%) was extremely obese. Two patients (13%) were active smokers. No patients had an active or previous record of corticosteroid therapy. No patients required postoperative lower limb physical therapy.

RESULTS

In terms of overall and cosmetic satisfaction, most patients reported that they were satisfied or very satisfied at all evaluations, and the proportion of very satisfied patients increased over time (p < 0.001). The harvested thigh's functional scores were 91% (p = 0.003) and 94% (p = 0.008) of the healthy thigh's score at 6 and 18 months, respectively. The complications reported were mild, and their proportions decreased in the first 18 months after surgery (p = 0.04).

CONCLUSIONS

The minimally invasive fascia lata harvesting technique for arthroscopic superior capsular reconstruction leads to donor site satisfactory subjective results and good functional outcomes at 18 months after surgery. According to these findings, donor site morbidity is not a valid argument against the use of this autograft for arthroscopic superior capsular reconstruction.

LEVEL OF EVIDENCE

Case series, level IV.

Allograft Tissue Safety and Technology

Allograft tissues are commonly used by orthopedic surgeons and are processed using a variety of technologies to increase safety and clinical use. For safety, although disease transmission is a tangible risk, this possibility has been dramatically minimized through modern tissue-processing methods. These include steps to prevent processing tissues with unacceptable bioburden through rigorous screening using donor medical and social histories along with microbial testing of recovered tissue and viral testing of donor serum. Potential bioburden is also controlled through aseptic recovery and processing methods and then reduced through disinfection steps that can include antibiotics, detergents, mechanical process, chemical solutions, and terminal sterilization. Processing steps may also include decellularization methods to lower immunogenic potential of some tissues. To enhance fusion potential of bone void fillers, demineralization steps may be used, and the resultant demineralized bone matrices may be combined with a carrier to improve handling. Bone void fillers and osteochondral allografts may also be specially processed to retain a living cellular component. To preserve relevant biological, biochemical, and physical properties of allografts for clinical use and ease of handling, a number of methods may be used which include: (1) refrigeration in media, (2) freeze-drying, (3) cryopreservation, (4) freezing, and (5) media storage at room temperature. As academic and industry research continue to drive advances, the future direction of allograft tissue likely includes injectables, coatings, cellular therapies, and combinations with other materials. The technology approaches outlined here will be further described along with future directions.

Patch-augmented rotator cuff surgery (PARCS) study-protocol for a feasibility study

BACKGROUND

A rotator cuff tear is a common disabling shoulder problem. Symptoms include pain, weakness, lack of shoulder mobility and sleep disturbance. Many patients require surgery to repair the tear; however, there is a high failure rate. There is a pressing need to improve the outcome of rotator cuff surgery and the use of patch augmentation to provide support to the healing process and improve patient outcomes holds new promise. Patches have been made using different materials (e.g. human/animal skin or intestine tissue, and completely synthetic materials) and processes (e.g. woven or a mesh). However, clinical evidence on their use is limited. The aim of the patch-augmented rotator cuff surgery (PARCS) feasibility study is to determine, using a mixed method approach, the design of a definitive randomised trial assessing the effectiveness and cost-effectiveness of a patch to augment surgical repair of the rotator cuff that is both acceptable to stakeholders and feasible.

METHODS

The objectives of this six-stage mixed methods feasibility study are to determine current practice, evidence and views about patch use; achieve consensus on the design of a randomised trial to evaluate patch-augmented rotator cuff surgery; and assess the acceptability and feasibility of the proposed design. The six stages will involve a systematic review of clinical evidence, two surveys of surgeons, focus groups and interviews with stakeholders, a Delphi study and a consensus meeting. The various stakeholders (including patients, surgeons, and representatives from industry, the NHS and regulatory bodies) will be involved across the six stages.

DISCUSSION

The PARCS feasibility study will inform the feasibility and acceptability of a randomised trial of the effectiveness and cost-effectiveness of a patch-augmented rotator cuff surgery. Consensus opinion on the basic design of a randomised trial will be sought.

TRIAL REGISTRATION

Not applicable.

Porcine Dermal Xenograft as Augmentation in the Treatment of Large Rotator Cuff Tears: Clinical and Magnetic Resonance Results at 2-Year Follow-Up

Purpose  The aim of the present retrospective study is to describe the results obtained at 2-year follow-up by using a porcine dermis-derived collagen membrane implanted as augmentation to treat large rotator cuff tears.

Methods  Thirty-five patients in total were included according to the following criteria: large or massive rotator cuff tear, confirmed during surgery, measuring between 3 and 5 cm in width and stage 1 to 2 fatty infiltration documented at magnetic resonance imaging (MRI). Patients underwent arthroscopic repair of the cuff augmented by the implantation of a porcine dermal collagen membrane. Patients were evaluated up to 24 months after surgery by the Constant score and MRI imaging to assess functional outcomes and re-tear rate. The results obtained were compared to those of a matched cohort of 35 patients operated by arthroscopic repair alone by the same surgical team.

Results  The application of the porcine membrane proved to be safe without scaffold-related adverse events documented. A statistically significant difference in the Constant score in favor of the treatment group was documented at the final evaluation ( p  = 0.036 ). Furthermore, a subgroup analysis revealed that patients treated by augmentation and presenting re-tear at MRI showed a significantly higher functional outcome compared with control patients with MRI evidence of re-tear ( p  = 0.0136).

Conclusion  Arthroscopic repair augmented by porcine dermal xenograft for the treatment of chronic and retracted rotator cuff tears with low-grade fatty degeneration proved to be safe and also effective, with higher functional score compared with the arthroscopic repair alone.

Level of Evidence  This is a Level III, retrospective cohort study.

Systematic review of the surgical management of rotator cuff repair with an augmentative patch: a feasibility study protocol

BACKGROUND

Shoulder pain is a common problem in the general population and is responsible for prolonged periods of disability, loss of productivity, absence from work and inability to carry out household activities. Rotator cuff problems account for up to 70% of shoulder pain problems and are the third most prevalent musculoskeletal disorder after those occurring in the lower back and neck. Rotator cuff surgery has high failure rates (25-50% within 12 months), and as a result, there is a pressing need to improve the outcome of rotator cuff surgery. Patch augmented surgery for rotator cuff repairs has recently been developed and is increasingly being used within the UK National Health Service. Patch augmented surgery could lead to a dramatic improvement in patient and surgical outcomes, but its clinical and cost effectiveness needs rigorous evaluation. The existing evidence on the use of patches may be at risk of bias as currently only a small number of single-centre comparative studies appear to have been carried out. Additionally, it is unclear for which patches a clinical study (comparative and non-comparative) has been conducted. This paper outlines the protocol for a systematic review intended to summarise the best available clinical evidence and will indicate what further research is required.

METHODS

Electronic databases (Medline, Embase and Cochrane) will be systematically searched between April 2006 and the present day for relevant publications using a specified search strategy, which can be adapted for the use in multiple electronic databases, and inclusion criteria. Screening of both titles and abstracts will be done by two independent reviewers with any discrepancies resolved by a third independent reviewer. Data extraction will include information regarding the type of participants, type of intervention and outcomes including but not limited to shoulder-specific function and pain scores, patch-related adverse events and type of study. The results will be summarised in a narrative review where qualitative analysis is not possible.

DISCUSSION

This review aims to collate the current evidence base regarding the use of patches to augment rotator cuff repair. The results of this review will help to develop, using consensus methods, the design of a definitive randomised trial assessing the clinical and cost-effectiveness of a patch to augment surgical repair of the rotator cuff that is both acceptable to stakeholders and is feasible.

SYSTEMATIC REVIEW REGISTRATION

CRD42017057908.

Surgical repair of large-to-massive rotator cuff tears seems to be a better option than patch augmentation or débridement and biceps tenotomy: a prospective comparative study

BACKGROUND

This prospective study compared the outcomes after 3 different treatments for large and massive rotator cuff tears.

METHODS

Patients with a diagnosis of large-to-massive rotator cuff tears were prospectively included. Patients were allocated in 3 groups: (1) arthroscopic complete repair (repair group), (2) open repair and xenograft patch augmentation (patch group), and (3) arthroscopic débridement and tenotomy of the long head of the biceps (débridement group). Patients were evaluated preoperatively and postoperatively at 3, 6, 12 and 24 months. The primary outcome measure was the Constant-Murley score.

RESULTS

The study included 32 consecutive patients. The mean improvement in the Constant-Murley score was +29.1 for the repair group (P < .01), +32.2 for the patch group (P < .01), and +20.1 for the débridement group (P < .01) at the final follow-up examination. No differences were found between the repair and patch groups, but the difference became significant between the débridement group and the patch group (P < .001) and also between the débridement group and the repair group (P < .002) at 12 months and the final follow-up. Moreover, 5 complications occurred in 11 patients in the patch group, whereas there was only 1 complication in the repair group and no complications in the débridement group.

CONCLUSION

The use of porcine dermis patches to augment repairs of massive and irreparable rotator cuff tears is not recommended because there is no benefit compared with repair without augmentation and patches result in more complications.

Enthesis Repair: Challenges and Opportunities for Effective Tendon-to-Bone Healing

On May 22, 2017, the National Institutes of Health (NIH)/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) hosted a roundtable on "Innovative Treatments for Enthesis Repair." A summary of the roundtable discussion, as well as a list of the extramural participants, can be found at https://www.niams.nih.gov/about/meetings-events/roundtables/roundtable-innovative-treatments-enthesis-repair. This paper reviews the challenges and opportunities for developing effective treatment strategies for enthesis repair that were identified at the roundtable discussion.

Repair of Massive and Irreparable Rotator Cuff Tear Using Arthroscopic Method

Rotator cuff tear stands as one of the major origins of shoulder discomfort and disability, especially in elderly patients over 60 years. Improvement of performance and reduction of pain hardly occur in patients with contracted rotator cuff tear. Despite therapeutic advances, yet there are many discussions over choosing the best type of treatment for major rotator cuff tear. Complete care of massive rotator cuff tear continues to be a challenge in shoulder surgery. Treatment options have changed in comparison with traditional treatment methods in open or arthroscopic debridement surgery with or without decompression. Recently, many treatments have been introduced, including a range of non-surgical treatments, acromioplasty by debridement, minor repair biceps tenotomy, tuberoplasty by biceps tenotomy, minor repair, mini-open rotator cuff repair, arthroscopic rotator cuff, muscle movement, reverse shoulder arthroscopy, soft tissue reinforcement and hemiarthroplasty. Non-surgical massive rotator cuff control is typically assigned for patients with insignificant pain. This therapy functions by changing activities, proper use of steroid injections and physical therapy with an emphasis on the anterior deltoid exercises. But the main problem is the selection of the best treatment and making the final decision. In general, in the arthroscopic, morbidity, postoperative pain along with hospital stay are less and the operation has better cosmetic results. So this information and our results have prompted us to study a variety of rotator cuff treatment methods with a focus on the arthroscopic treatment.

Recurrent tears of the rotator cuff: Effect of repair technique and management options

Retears of the rotator cuff, following operative repair, is not an uncommon event. Various factors have been shown to influence recurrence including the technique of repair. Multiple techniques have been performed with varying results and complications. The repair technique significantly affects the rate and pattern of retears. Although risk of retears with double row and suture bridge techniques is relatively low, medial cuff failure is a potential complication which poses significant challenges when revision repair is undertaken. Modifications in surgical techniques in, both, double row and suture bridge repairs can help decrease the risk of medial cuff failure. Thorough analysis of retear rates and patterns reported, and their relation with the repair technique, provides new insights about the pathogenesis of rotator cuff retears, their future prevention and appropriate management.

Biomechanical, Biochemical, and Cell Biological Evaluation of Different Collagen Scaffolds for Tendon Augmentation

Tendon augmentation is increasingly clinically relevant due to rising amount of tendon ruptures because of the aging and more demanding population. Therefore, newly developed scaffolds based on bovine epoxide stabilized collagen maintaining the native fibril-like collagen structure were characterized and compared to two commercially available porcine collagen scaffolds. For biomechanical testing (ultimate load, ultimate stress, stiffness, and elastic modulus), bovine collagen scaffolds were hydrated and compared to reference products. Cell viability and proliferation were assessed by seeding human primary fibroblasts on each collagen-based scaffold and cultured over various time periods (3 d, 7 d, and 14 d). Live/dead staining was performed and metabolic cell activity (WST-1 assay) was measured. Biochemical degradability was investigated by enzymatic digestion. The bovine collagen scaffold showed significantly enhanced biomechanical properties. These persisted over different rehydration times. Cell biological tests revealed that the bovine collagen scaffolds support reproducible cell colonization and a significant increase in the number of viable cells during cultivation. The results are comparable with the viability and proliferation rate of cells grown on porcine reference materials. With regard to biochemical degradability, all tested materials showed comparable resistance to enzymatic degradation in vitro. Due to imitating the natural tendon structure the new scaffold material is supposed to provide beneficial effects in future clinical application.

Orthopaedic regenerative tissue engineering en route to the holy grail: disequilibrium between the demand and the supply in the operating room

Orthopaedic disorders are very frequent, globally found and often partially unresolved despite the substantial advances in science and medicine. Their surgical intervention is multifarious and the most favourable treatment is chosen by the orthopaedic surgeon on a case-by-case basis depending on a number of factors related with the patient and the lesion. Numerous regenerative tissue engineering strategies have been developed and studied extensively in laboratory through in vitro experiments and preclinical in vivo trials with various established animal models, while a small proportion of them reached the operating room. However, based on the available literature, the current strategies have not yet achieved to fully solve the clinical problems. Thus, the gold standards, if existing, remain unchanged in the clinics, notwithstanding the known limitations and drawbacks. Herein, the involvement of regenerative tissue engineering in the clinical orthopaedics is reviewed. The current challenges are indicated and discussed in order to describe the current disequilibrium between the needs and solutions made available in the operating room. Regenerative tissue engineering is a very dynamic field that has a high growth rate and a great openness and ability to incorporate new technologies with passion to edge towards the Holy Grail that is functional tissue regeneration. Thus, the future of clinical solutions making use of regenerative tissue engineering principles for the management of orthopaedic disorders is firmly supported by the clinical need.

Treatment Strategy for Irreparable Rotator Cuff Tears

Recently, patients with shoulder pain have increased rapidly. Of all shoulder disorders, rotator cuff tears (RCTs) are most prevalent in the middle-aged and older adults, which is the primary reason for shoulder surgery in the population. Some authors have reported that up to 30% of total RCTs can be classified as irreparable due to the massive tear size and severe muscle atrophy. In this review article, we provide an overview of treatment methods for irreparable massive RCTs and discuss proper surgical strategies for RCTs that require operative management.

Outcomes of rotator cuff augmentation surgery with autologous fascia lata

OBJECTIVE

To evaluate whether augmentation grafts using autologous fascia lata improve functional results for rotator cuff repairs and reduce the retear rate compared to those without augmentation.

MATERIAL AND METHODS

This is a prospective evaluation comprising 20 patients with a complete symptomatic rotator cuff tear. The operations were carried out from a superior approach performing a total cuff repair, for 10 patients we used a suture augmented with an autologous graft taken from their own fascia lata while unaugmented sutures were used for the other 10 patients. The follow-up period lasted for one year post-intervention. We measured variables for tear type, functionality and pain, both baseline and at 6 and 12-month follow ups. We evaluated retear incidence in each group as well as each group's pain and functionality response.

RESULTS

The improved pain levels in the non-graft group evolved gradually over time. Conversely, in the group with the augmentation grafts, average Constant-Murley shoulder outcome scores at six months were already above 10 and were maintained at 12 months. One retear occurred in the graft group and 2 in the group without grafts, thus presenting no significant differences. There were no significant changes in pain and function values at the one year follow up in either group.

CONCLUSION

Our preliminary results regarding rotator cuff augmentation surgery with autologous fascia lata showed a significant improvement in pain levels after 6 months compared to the patients with no augmentation, who required 12 months to reach the same values. After a year of follow up, there were no differences between the mean Constant and pain scores in either intervention group The number of retears in the non-graft group was greater than that in the group with grafts although the difference was not significant.

Biceps Autograft Augmentation for Rotator Cuff Repair: A Systematic Review

PURPOSE

To improve surgical outcomes in patients with massive cuff defects, different techniques and augmentations are proposed. The biceps tendon is easily available as an autograft. Our aim was to conduct a qualitative systematic review of various methods and surgical techniques that use a biceps autograft (BAG) for rotator cuff repair. Functional outcomes are also reported. We hypothesized that by using a BAG to treat massive rotator cuff tears, a more anatomic and biomechanical reconstruction could be achieved compared with other techniques.

METHODS

A qualitative systematic review was conducted (MEDLINE and Embase databases) to inventory surgical techniques for use of a BAG for rotator cuff repair. The following search terms were used for MEDLINE: biceps AND (augment* OR autograft* OR transplantation* OR (cuff AND graft*) OR biceps-incorporat*). Studies were included if the following criteria were fulfilled: description of surgical technique, only human subjects, functional outcomes noted, all study designs except technical notes, and no restrictions on study date. The quality of the studies was assessed in a standardized manner using a tool based on the Cochrane handbook.

RESULTS

We identified 981 studies; among these, 8 case series met the inclusion criteria. We identified 6 studies as high quality and 2 as medium quality. Different techniques for harvest and augmentation were used. Some studies left the proximal or distal portion intact, whereas others used it as a free graft. The clinical results of these studies showed significantly improved function, pain relief, and range of motion at follow-up, although this was not compared with a control group. The constructs were intact on magnetic resonance imaging in most patients (82%) within 2 years.

CONCLUSIONS

It can be concluded that use of a BAG is an option for augmentation in massive rotator cuff tears, although no definitive recommendations can be given. This is based on Level IV medium- and high-quality studies. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Cell-material interactions in tendon tissue engineering

The interplay between cells and materials is a fundamental topic in biomaterial-based tissue regeneration. One of the principles for biomaterial development in tendon regeneration is to stimulate tenogenic differentiation of stem cells. To this end, efforts have been made to optimize the physicochemical and bio-mechanical properties of biomaterials for tendon tissue engineering. However, recent progress indicated that innate immune cells, especially macrophages, can also respond to the material cues and undergo phenotypical changes, which will either facilitate or hinder tissue regeneration. This process has been, to some extent, neglected by traditional strategies and may partially explain the unsatisfactory outcomes of previous studies; thus, more researchers have turned their focus on developing and designing immunoregenerative biomaterials to enhance tendon regeneration. In this review, we will first summarize the effects of material cues on tenogenic differentiation and paracrine secretion of stem cells. A brief introduction will also be made on how material cues can be manipulated for the regeneration of tendon-to-bone interface. Then, we will discuss the characteristics and influences of macrophages on the repair process of tendon healing and how they respond to different materials cues. These principles may benefit the development of novel biomaterials provided with combinative bioactive cues to activate tenogenic differentiation of stem cells and pro-resolving macrophage phenotype.

STATEMENT OF SIGNIFICANCE

The progress achieved with the rapid development of biomaterial-based strategies for tendon regeneration has not yielded broad benefits to clinical patients. In addition to the interplay between stem cells and biomaterials, the innate immune response to biomaterials also plays a determinant role in tissue regeneration. Here, we propose that fine-tuning of stem cell behaviors and alternative activation of macrophages through material cues may lead to effective tendon/ligament regeneration. We first review the characteristics of key material cues that have been manipulated to promote tenogenic differentiation and paracrine secretion of stem cells in tendon regeneration. Then, we discuss the potentiality of corresponding material cues in activating macrophages toward a pro-resolving phenotype to promote tissue repair.

The Role of Biologic Therapy in Rotator Cuff Tears and Repairs

PURPOSE OF REVIEW

The purpose of this review was to establish the foundation of the major biologic adjuvants to rotator cuff repairs and review recent scientific findings.

RECENT FINDINGS

Platelet-rich plasma (PRP) overall has no significant impact on functional outcomes and repair integrity, but may be more advantageous in small to medium tears. Further studies should focus on leukocyte-rich versus poor preparations and the use of PRP in patients that are high risk for repair failure. Biologic and synthetic patches or augments provide mechanical stability for large and massive rotator cuff tears and decrease re-tear rates. Mesenchymal stem cells have demonstrated improved healing rates without an impact on outcomes. Cytokines and growth factors show promise in animal models, but require human trials to further evaluate. In massive or revision repairs, allograft or synthetic patch augmentation should be considered. Platelet-rich plasma may have benefit in smaller tears. Further studies are needed to evaluate the value of mesenchymal stem cells and various cytologic chemical signals.

[Arthroscopic rotator cuff surgery : New and established methods]

This present article summarizes established and current developments and aspects of rotator cuff surgery. Achieved milestones as well as current approaches are presented and assessed with respect to their clinical and radiographic impact. Despite biomechanical and technical improvements in modern rotator cuff repair techniques, re-defect and re-tearing rates could not be fully eliminated. Meanwhile, the importance of biological processes around successful tendon-bone reintegration has been increasingly recognized. Hence, this article presents the current scientific standing regarding biological growth factors, platelet-rich plasma and rotator cuff augmentation techniques (with allogenic/autologous grafts). In summary, there are clear biomechanical advantages as well as many promising approaches to biological augmentation; however, the latter have not yet been transferred into regular clinical application.

Porcine Dermis Patch Augmentation of Supraspinatus Tendon Repairs: A Pilot Study Assessing Tendon Integrity and Shoulder Function 2 Years After Arthroscopic Repair in Patients Aged 60 Years or Older

PURPOSE

To investigate the 2-year postoperative clinical and subjective outcomes after arthroscopic rotator cuff repair (ARCR) with xenologous porcine dermal patch augmentation compared with ARCR alone.

METHODS

Patients aged 60 years or older with a complete supraspinatus (SSP) tendon tear underwent primary ARCR with a transosseous-equivalent technique. By use of a matched-pair comparative trial design, a consecutive series of 20 patients receiving additional xenologous porcine dermal patch augmentation (patch group) was matched by tear location with 20 patients who received ARCR only (control group). Prior conservative treatment failed in all patients. Patients with concomitant pathologies precluding accurate repair assessment, partial or open reconstruction, or a latissimus dorsi and/or pectoralis major muscle transfer were excluded. Patients reported daily pain levels for 10 days after surgery. Clinical parameters and various patient-reported outcome scores were documented preoperatively and at 3, 6, and 24 months after surgery. Repair integrity was determined by magnetic resonance imaging or ultrasound at 24 months. Adverse events were recorded. Group outcome differences were analyzed with t tests, Fisher exact tests, and mixed models.

RESULTS

Patients in both groups were aged 67 years on average (range, 60-74 years), and 70% of patients were men. Patients in the patch group had slightly more SSP fatty infiltration preoperatively. Patch surgical procedures were on average 22 minutes longer than control interventions (P = .003). At 24 months, 4 patients and 9 patients were diagnosed with a recurrent SSP tendon defect in the control group (n = 20) and patch group (n = 19), respectively (relative risk, 2.4; P = .096). Of 11 defects (85%) identified as medial cuff failure, 8 occurred in the patch group. Pain rated by all patients decreased from postoperative day 1 to day 10 without any significant group difference (P = .348). No significant group differences were noted for other outcome parameters, and recurrent defects had no relevant effect on functional outcomes. Local complications (including recurrent defects) occurred in 8 patients in the control group and 12 in the patch group (P = .343).

CONCLUSIONS

Our pilot study supports the view that an SSP tear repair with porcine dermal xenograft augmentation does not benefit patients in terms of reducing the risk of a recurrent tendon defect or improving shoulder function up to 24 months after surgical repair.

LEVEL OF EVIDENCE

Level III, therapeutic study, retrospective comparative trial.

Histological and ultrastructural evaluation of human decellularized matrix as a hernia repair device

Recently, interest has been increasing for human decellularized matrices, due to their ability to reduce numerous side effects related to hernia repair. To date, only animal studies investigated the biological interaction post-implant of human decellularized matrices for soft tissue repair. Therefore, the aim of this study was to evaluate the morphological response one year post implant of human decellularized matrix, through morphological analysis of human biopsies. The histological and ultrastructural results revealed a perfect cellular repopulation and neoangiogenesis, with minimal inflammatory response and a well-organized collagen matrix. The results have indicated that this scaffold can be an effective treatment for hernia.

Increasing age and tear size reduce rotator cuff repair healing rate at 1 year

Background and purpose - There is a need to understand the reasons why a high proportion of rotator cuff repairs fail to heal. Using data from a large randomized clinical trial, we evaluated age and tear size as risk factors for failure of rotator cuff repair. Patients and methods - Between 2007 and 2014, 65 surgeons from 47 hospitals in the National Health Service (NHS) recruited 447 patients with atraumatic rotator cuff tendon tears to the United Kingdom Rotator Cuff Trial (UKUFF) and 256 underwent rotator cuff repair. Cuff integrity was assessed by imaging in 217 patients, at 12 months post-operation. Logistic regression analysis was used to determine the influence of age and intra-operative tear size on healing. Hand dominance, sex, and previous steroid injections were controlled for. Results - The overall healing rate was 122/217 (56%) at 12 months. Healing rate decreased with increasing tear size (small tears 66%, medium tears 68%, large tears 47%, and massive tears 27% healed). The mean age of patients with a healed repair was 61 years compared with 64 years for those with a non-healed repair. Mean age increased with larger tear sizes (small tears 59 years, medium tears 62 years, large tears 64 years, and massive tears 66 years). Increasing age was an independent factor that negatively influenced healing, even after controlling for tear size. Only massive tears were an independent predictor of non-healing, after controlling for age. Interpretation - Although increasing age and larger tear size are both risks for failure of rotator cuff repair healing, age is the dominant risk factor.

Biologic Scaffolds

Biologic scaffold materials composed of allogeneic or xenogeneic extracellular matrix are commonly used for the repair and functional reconstruction of injured and missing tissues. These naturally occurring bioscaffolds are manufactured by the removal of the cellular content from source tissues while preserving the structural and functional molecular units of the remaining extracellular matrix (ECM). The mechanisms by which these bioscaffolds facilitate constructive remodeling and favorable clinical outcomes include release or creation of effector molecules that recruit endogenous stem/progenitor cells to the site of scaffold placement and modulation of the innate immune response, specifically the activation of an anti-inflammatory macrophage phenotype. The methods by which ECM biologic scaffolds are prepared, the current understanding of in vivo scaffold remodeling, and the associated clinical outcomes are discussed in this article.

Quantitative analysis of immune cell subset infiltration of supraspinatus muscle after severe rotator cuff injury

Rotator cuff tears cause muscle degeneration that is characterized by myofiber atrophy, fatty infiltration, and fibrosis and is minimally responsive to current treatment options. The underlying pathogenesis of rotator cuff muscle degeneration remains to be elucidated, and increasing evidence implicates immune cell infiltration as a significant factor. Because immune cells are comprised of highly heterogeneous subpopulations that exert divergent effects on injured tissue, understanding trafficking and accumulation of immune subpopulations may hold the key to more effective therapies. The present study quantifies subpopulations of immune cells infiltrating the murine supraspinatus muscle after severe rotator cuff injury that includes tenotomy and denervation. Rotator cuff injury stimulates dramatic infiltration of mononuclear phagocytes, enriches mononuclear phagocytes in non-classical subpopulations, and enriches T lymphocytes in T_H and T_reg subpopulations. The combination of tenotomy plus denervation significantly increases mononuclear phagocyte infiltration, enriches macrophages in the non-classical subpopulation, and decreases T lymphocyte enrichment in T_H cells compared to tenotomy alone. Depletion of circulating monocytes via liposomal clodronate accelerates supraspinatus atrophy after tenotomy and denervation. The study may aid rational design of immunologically smart therapies that harness immune cells to enhance outcomes after rotator cuff tears.

Biological incorporation of human acellular dermal matrix used in Achilles tendon repair

Human acellular dermal matrices (ADMs) are used successfully in a variety of procedures, including sports medicine related, wound repair, and breast reconstructions, but the mechanism of repair is still not fully understood. An opportunity to explore this mechanism presented itself when a patient experienced a rerupture of the native tendon due to a fall that occurred 2 months after undergoing an Achilles tendon repair using Matracell treated ADM. The ADM was removed and an extensive histology analysis was performed on the tissue. Additionally, a literature review was conducted to determine the mechanism of ADM integration into the tendon structure and explore if differences in this mechanism exist for different types of human ADMS. The histology analysis demonstrated that the healing process during a tendon reconstruction procedure is similar to that of wound healing. Furthermore, the literature review showed that differences exist in the mechanism for integration among various human ADMs and that these differences may be due to variances in the methods and technologies that manufactures use to process human ADMs.

Latissimus Dorsi Transfer in Posterior Irreparable Rotator Cuff Tears

BACKGROUND

Massive rotator cuff tears pose a difficult and complex challenge even for the experienced surgeon; inability to repair these tears by conventional means designates them as irreparable, while management becomes quite taxing. Several operative options have been suggested for the management of such lesions with varying degrees of success, while it is imperative to match patient demands and expectations to the predicted outcome.

METHODS

Research articles are examined and key concepts are discussed, in order to provide an evidence based review of the available literature. The anatomy and pathomechanics along with the indications, contraindications and surgical techniques are reported.

RESULTS

Transfer of the Latissimus dorsi has been used with success to restore shoulder function in deficits of the posterior rotator cuff. Although it can be used in a variety of settings, the ideal patient for a Latissimus dorsi tendon transfer is a young and active individual, with no glenohumeral osteoarthritis that has a severe disability and weakness related to an irreparable posterior cuff tear.

CONCLUSION

Tendon transfers have proved to be a successful treatment option in salvaging this difficult problem, providing pain relief and restoring shoulder function. Despite the excellent functional outcomes and pain suppression following operation, a variety of factors may affect the outcome; thus making indications and preoperative assessment a valuable component.

The Rotator Cuff Organ: Integrating Developmental Biology, Tissue Engineering, and Surgical Considerations to Treat Chronic Massive Rotator Cuff Tears

The torn rotator cuff remains a persistent orthopedic challenge, with poor outcomes disproportionately associated with chronic, massive tears. Degenerative changes in the tissues that comprise the rotator cuff organ, including muscle, tendon, and bone, contribute to the poor healing capacity of chronic tears, resulting in poor function and an increased risk for repair failure. Tissue engineering strategies to augment rotator cuff repair have been developed in an effort to improve rotator cuff healing and have focused on three principal aims: (1) immediate mechanical augmentation of the surgical repair, (2) restoration of muscle quality and contractility, and (3) regeneration of native enthesis structure. Work in these areas will be reviewed in sequence, highlighting the relevant pathophysiology, developmental biology, and biomechanics, which must be considered when designing therapeutic applications. While the independent use of these strategies has shown promise, synergistic benefits may emerge from their combined application given the interdependence of the tissues that constitute the rotator cuff organ. Furthermore, controlled mobilization of augmented rotator cuff repairs during postoperative rehabilitation may provide mechanotransductive cues capable of guiding tissue regeneration and restoration of rotator cuff function. Present challenges and future possibilities will be identified, which if realized, may provide solutions to the vexing condition of chronic massive rotator cuff tears.

The biology of rotator cuff healing

Despite advances in surgical reconstruction of chronic rotator cuff (RC) tears leading to improved clinical outcomes, failure rates of 13-94% have been reported. Reasons for this rather high failure rate include compromised healing at the bone-tendon interface, as well as the musculo-tendinous changes that occur after RC tears, namely retraction and muscle atrophy, as well as fatty infiltration. Significant research efforts have focused on gaining a better understanding of these pathological changes in order to design effective therapeutic solutions. Biological augmentation, including the application of different growth factors, platelet concentrates, cells, scaffolds and various drugs, or a combination of the above have been studied. It is important to note that instead of a physiological enthesis, an abundance of scar tissue is formed. Even though cytokines have demonstrated the potential to improve rotator cuff healing in animal models, there is little information about the correct concentration and timing of the more than 1500 cytokines that interact during the healing process. There is only minimal evidence that platelet concentrates may lead to improvement in radiographic, but not clinical outcome. Using stem cells to biologically augment the reconstruction of the tears might have a great potential since these cells can differentiate into various cell types that are integral for healing. However, further studies are necessary to understand how to enhance the potential of these stem cells in a safe and efficient way. This article intends to give an overview of the biological augmentation options found in the literature.