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

3-Dimensional Bioprinting of a Tendon Stem Cell-Derived Exosomes Loaded Scaffold to Bridge the Unrepairable Massive Rotator Cuff Tear

BACKGROUND

Unrepairable massive rotator cuff tears (UMRCTs) are challenging to surgeons owing to the severely retracted rotator cuff musculotendinous tissues and extreme defects in the rotator cuff tendinous tissues.

PURPOSE

To fabricate a tendon stem cell-derived exosomes loaded scaffold (TSC-Exos-S) and investigate its effects on cellular bioactivity in vitro and repair in a rabbit UMRCT model in vivo.

STUDY DESIGN

Controlled laboratory study.

METHODS

TSC-Exos-S was fabricated by loading TSC-Exos and type 1 collagen (COL-I) into a 3-dimensional bioprinted and polycaprolactone (PCL)-based scaffold. The proliferation, migration, and tenogenic differentiation activities of rabbit bone marrow stem cells (BMSCs) were evaluated in vitro by culturing them in saline, PCL-based scaffold (S), COL-I loaded scaffold (COL-I-S), and TSC-Exos-S. In vivo studies were conducted on a rabbit UMRCT model, where bridging was repaired with S, COL-I-S, TSC-Exos-S, and autologous fascia lata (FL). Histological and biomechanical analyses were performed at 8 and 16 weeks postoperatively.

RESULTS

TSC-Exos-S exhibited reliable mechanical strength and subcutaneous degradation, which did not occur before tissue regeneration. TSC-Exos-S significantly promoted the proliferation, migration, and tenogenic differentiation of rabbit BMSCs in vitro. In vivo studies showed that UMRCT repaired with TSC-Exos-S exhibited significant signs of tendinous tissue regeneration at the bridging site with regard to specific collagen staining. Moreover, no significant differences were observed in the histological and biomechanical properties compared with those repaired with autologous FL.

CONCLUSION

TSC-Exos-S achieved tendinous tissue regeneration in UMRCT by providing mechanical support and promoting the trend toward tenogenic differentiation.

CLINICAL RELEVANCE

The present study proposes a potential strategy for repairing UMRCT with severely retracted musculotendinous tissues and large tendinous tissue defects.

Bridging repair reinforced with artificial ligament as an internal brace for irreparable massive rotator cuff tears

BACKGROUND

The irreparable massive rotator cuff tear (IMRCT) is challenging to manage. Although various surgical options have been proposed to treat IMRCTs, the optimal surgical technique remains controversial. Arthroscopic bridging patch repair is clinically used for treating IMRCTs, but the healing rate of the patch graft is negatively affected by superior shift of the humeral head. This study aimed to evaluate the clinical efficacy of artificial ligament as an internal brace (IB) reinforcing fascia lata autograft bridging repair (ABR) in the treatment of IMRCTs.

METHODS

The data of 50 patients with IMRCTs who underwent ABR reinforced with artificial ligament as an IB (ABR + IB) (internal brace group) or ABR alone (control group) were retrospectively evaluated preoperatively and at 2-year follow-up. Clinical outcomes were assessed based on the shoulder activity, of which the strength was measured using a 0-10 points manual muscle test scale, American Shoulder and Elbow Surgeons score, and visual analog scale for pain. Imaging outcomes were evaluated based on acromiohumeral distance (AHD), Hamada grade, Goutallier grade, and the status of fascia lata grafts as per radiographs or magnetic resonance imaging findings.

RESULTS

Both groups showed significantly better results in shoulder activity, American Shoulder and Elbow Surgeons score, visual analog scale score, and AHD at 2-year follow-up compared with preoperative levels (P < .001). Compared with the control group (n = 24), the internal brace group (n = 26) had better mean AHD (7.0 ± 1.4 mm vs. 5.9 ± 1.0 mm, P = .002), mean improvement in AHD (3.3 ± 1.5 mm vs. 2.0 ± 0.6 mm, P < .001), healing rate of autografts (92.3% vs. 54.2%, P = .002), and improvement rate of Hamada grade (73.1% vs. 41.7%, P = .025) at 2-year follow-up. No significant differences were found in active elevation, active external rotation, active internal rotation, abduction strength, external rotation strength, internal rotation strength, American Shoulder and Elbow Surgeons score, or visual analog scale between the 2 groups at 2-year follow-up.

CONCLUSION

Both the ABR + IB and ABR improved the postoperative short-term clinical and imaging outcomes in managing IMRCTs, the ABR + IB is statistically superior to ABR alone in terms of healing rate of the bridging graft, AHD, and Hamada grade at 2-year follow-up, while further clinical investigations with larger sample size and longer follow-ups are required to validate the clinical significance of this novel technique for IMRCTs.

Reinforcement Techniques in Arthroscopic Repair of Large-to-Massive Rotator Cuff Tears: A Comparative Study of Superior Capsule Reconstruction and Patch Graft Augmentation

Background: Large-to-massive rotator cuff tears (LMRCTs) present challenges in achieving successful repair due to factors such as muscle atrophy and tendon retraction. Arthroscopic rotator cuff repair (ARCR) with reinforcement techniques like superior capsule reconstruction (SCR) or patch graft augmentation (PGA) has emerged as a less invasive option to improve shoulder joint stability and prevent retear. This study aimed to compare the clinical and radiological outcomes of SCR and PGA as reinforcement techniques for the arthroscopic repair of LMRCTs. Methods: A single-center retrospective study was conducted on patients undergoing LMRCT repair between January 2019 and December 2021. Patients were divided into two groups: those receiving SCR (Group 1) and those receiving PGA (Group 2). Various clinical parameters including range of motion, functional scores, and radiological assessments were evaluated preoperatively and six months postoperatively. Results: Both SCR and PGA techniques demonstrated significant improvements in the range of motion and clinical scores postoperatively. However, Group 2 showed higher postoperative SST and UCLA scores compared to Group 1. Radiologically, there was a slightly higher retear rate in Group 2, although this was not statistically significant. Group 2 also had a shorter mean duration of surgery compared to Group 1. Conclusions: In the arthroscopic repair of LMRCTs, both SCR and PGA techniques exhibit favorable clinical and radiological outcomes. Despite the simplicity of PGA compared to SCR, it offers comparable results with a shorter surgical duration, making it a feasible reinforcement option for surgeons.

Rotator Cuff Repair With Patch Augmentation Is Associated With Lower Retear Rates for Large Tears: A Systematic Review of Randomized Controlled Trials

PURPOSE

To perform a systematic review of randomized controlled trials comparing clinical outcomes of rotator cuff repair with and without patch augmentation.

METHODS

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify randomized controlled trials that directly compared outcomes between rotator cuff repair (RCR) with versus without patch augmentation. Patients were evaluated based on retear rate, histological outcomes, radiological outcomes, and patient-reported outcomes (Constant score; American Shoulder and Elbow Surgeons [ASES] score; University of California-Los Angeles shoulder scale; Simple Shoulder Test; EuroQol-visual analog scale; Disabilities of the Arm, Shoulder and Hand score; and PENN shoulder score questionnaire).

RESULTS

Six studies (1 level I, 5 level II) met inclusion criteria, including 188 patients undergoing RCR alone (Control) and 193 patients undergoing RCR with patch augmentation (Patch). Patient age ranged from 56.0 to 68.0 years. The mean follow-up time ranged from 14.0 to 68.4 months. The average body mass index ranged from 24.4 to 29.4, and the overall percentage of males ranged from 32.5% to 82.3%. Three studies found significantly decreased retear rates with patch augmentation. The retear rate ranged from 34.0% to 65.4% in the Control group and 9.1% to 52.9% in the Patch group. One study found a significant difference for the Constant score favoring the Patch group. Two studies found a significant difference for the ASES score favoring the Patch group. One study found significantly better results with patch augmentation in terms of repaired tendon thickness and footprint coverage, based on magnetic resonance imaging.

CONCLUSIONS

Patch augmentation of rotator cuff repairs may be associated with lower retear rates for large tears. There is limited evidence to suggest that patch augmentation is associated with improved patient-reported outcomes.

LEVEL OF EVIDENCE

Level II, systematic review of level I and II studies.

A retrospective comparative study of surgical outcomes following femoral fascia patching and iliotibial ligament bony patching for primary irreparable rotator cuff tears in a geriatric population

INTRODUCTION

We performed two surgical techniques for primary irreparable rotator cuff tears: a patch technique using the femoral fascia as a graft (F technique) and a patch technique using the bony iliotibial ligament (I technique). We then evaluated the outcomes of both surgical methods.

MATERIALS AND METHODS

This study included 28 patients who were diagnosed with primary irreparable rotator cuff tears from April 2008 to April 2014. Among them, 13 underwent the F technique, whereas 15 underwent the I technique. Each clinical shoulder score was evaluated preoperatively and 2 years after surgery. The cuff integrity was evaluated via magnetic resonance imaging 2 years after surgery, with cases suffering a retear after surgery undergoing retear site examination. In group I, computed tomography (CT) was performed 3-4 months after surgery to investigate the bony part of the patch and bony fusion of the footprint.

RESULTS

Both groups showed significant improvements in the pre- and postoperative mean clinical score values. Group I had significantly better postoperative scores than group F. Postoperative retear rates were 33.3% and 76.9% for groups I and F, respectively, with group I having a significantly lower retear rate (P = 0.03). All 5 retears in group I were located at the suture between the residual rotator cuff and the graft, whereas 7 of the 10 retears in group F were located at the fixation of the graft and footprint and the remaining 3 were central. CT results in group I showed that all 15 patients had bony fusion between the bony part of the patch and the footprint.

CONCLUSION

The I technique was significantly superior to the F technique in terms of postoperative clinical scores and retear rates, suggesting its advantage for rotator cuff tissue reconstruction.

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.

Midterm outcomes of autologous bridging of rotator cuff tears with an autologous tendon patch (TEAR patch)

BACKGROUND

Large and massive rotator cuff tears and tears after failed surgical repair are a challenging clinical problem with different treatment options. The purpose of the study was to evaluate the midterm outcomes after rotator cuff repair (RCR) with autologous hamstring tendon graft bridging (tissue-enhanced autologous rotator cuff repair [TEAR] patch) with the hypothesis that outcomes would be reasonable and complication rates would be low.

METHODS

This is a retrospective case series study of patients who underwent open RCR using a TEAR patch from June 2015 to March 2019. The exclusion criteria included evidence of cuff tear arthropathy, advanced fatty infiltration, moderate-to-severe arthropathy, and workers compensation board or litigation involved. Clinical outcome measures were Constant score; Disabilities of the Arm, Shoulder and Hand score; Simple Shoulder Test; Subjective Shoulder Value; range of motion (ROM); and manual muscle test for forward elevation, abduction, external and internal rotation, patient satisfaction, and willingness to perform the operation again. Radiographic outcome measures were magnetic resonance imaging, ultrasound, and radiographs: graft integrity and acromiohumeral distance (AHD).

RESULTS

A total of 44 patients were followed (89%) for ≥2 years (45 shoulders, mean age 60.3 years [48-76 years], mean follow-up 4.3 years [2-6 years]). All clinical outcome measures (Constant score, Disabilities of the Arm, Shoulder and Hand score, Simple Shoulder Test, Subjective Shoulder Value, ROM, and manual muscle test) demonstrated significant improvement except active external and internal rotation. At 2 years of follow-up, the mean patient satisfaction was high (12.2 of 15 points), and 33 of 38 patients (73.3%) would perform the operation again. A perfect graft integration was observed in 30 (66.7%), a small gap in 7 (15.6%), a retear in 3 (7%), and a complete failure of the tendon patch in 5 (11%) patients. Graft integrity was strongly correlated with the postoperative AHD (r = 0.599, P = .001) and the gain in AHD (r = 0.599, P = .001) but not with ROM or patient-reported outcome measures or patient satisfaction. Four patients required revision surgeries (3 due to deep infection and 1 for poor function and pain).

CONCLUSIONS

Midterm clinical and radiographic outcomes after RCR with graft bridging using a TEAR patch were reasonable. The procedure resulted in improved shoulder function and a high level of patient satisfaction. The revision rate is acceptable in view of the specific patient group and treatment alternatives. The described technique of the TEAR patch can be a valuable alternative to existing methods and a new autograft source for rotator cuff surgeries that need bridging of a tendon defect.

Repair of chronic and large rotator cuff tears using extra-synovial autografts: An experimental study in rabbits

Purpose

To investigate whether and how extra-synovial autografts can enhance the reconstruction of chronic and large rotator cuff tears in a rabbit subscapularis model.

Methods

Twenty rabbits were used to create a large subscapularis tear bilaterally. Six weeks later, the right shoulder of each rabbit was operated to repair the tear with an extra-synovial autograft, whereas the left shoulder did not undergo any surgery. At 6 and 12 weeks after the second procedure, the specimens underwent biomechanical and histological evaluation. Six more rabbits were used only as a normal reference.

Results

Biomechanical evaluation demonstrated that the ultimate load to failure of the Graft group (184.1 ± 35.7 N) was significantly higher (p = 0.04) than that of the Defect group (144.5 ± 32.2 N) at 12 weeks after repair, rising to 76% of the normal subscapularis tendon tensile strength. Histological analysis revealed an enhanced healing environment with neoangiogenesis and decreased inflammatory response at the repair site. Moreover, the tendon maturing score of the Graft group increased substantially from 6 (15.8 ± 0.9) to 12 (23.1 ± 0.6) weeks after repair (p = 0.01).

Conclusion

In vivo data support the efficacy of extra-synovial autograft interposition in repairing chronic and large rotator cuff tears in a rabbit subscapularis model. The autografts were capable of enhancing the biomechanical properties of the repaired tendons, as evidenced by increased tensile strength, and forming new connective tissue simulating a fibrocartilage zone, as revealed by histological evaluation.

Level of Evidence

N/A.

Augmentation of Rotator Cuff Repair Using Umbilical Cord Graft: A Preliminary Observational Study

Due to the high rate of rotator cuff re-tear there is an extensive research on augmentation of rotator cuff repairs. The purpose of this single center, prospective study was to evaluate the results of augmentation of the rotator cuff repair with an umbilical cord allograft. The graft group in which the rotator cuff repair was augmented with the graft as an on-lay patch was consisted of 14 patients, while the control group was consisted of 10 patients. The primary outcome of the study was incidence of rotator cuff retears, while secondary outcomes included functional and pain scores. At 6 mo there was a significantly higher incidence of retears in the control group (30%) compared to the graft group (0%; P = 0.028), while at 12 mo the retear rates were statistically similar for the two groups (P = 0.46). The Constant-Murley scores, the ASES scores and the VAS score were similar (P > 0.05) for the two groups at all study times. The results of the study indicated that augmentation of the cuff repair with human umbilical cord graft can result in similar patient reported outcomes compared to a cuff repair without augmentation, but with a lower re-tear rate at 6 mo.

Rotator Cuff Augmentation: Its Role and Best Practices

Rotator cuff tears are a common source of pain and impairment in the shoulder. Healing of the rotator cuff tendons following repair has been associated with improved patient outcomes. While there have been many technical improvements in surgical techniques for rotator cuff repair, failure rates are still surprisingly high. Augmentation of these repairs has been shown to help with fixation biomechanics as well as healing rates. The described types of augments include autograft, allograft, xenograft, and synthetic options. This report reviews the commonly available types of augments and some of the outcomes associated with their use.

The composition and mechanical properties of porcine placental ECM from three different breeds

Biologic scaffolds are extensively used in various clinical applications such as musculotendinous reconstruction, hernia repair or wound healing. Biologic scaffolds used in these applications vary in species, breed and tissue of origin, and other variables that affect their properties. Decellularization and sterilization processes also determine the characteristics of these scaffolds. The goal of the present study is to compare the composition and mechanical properties of decellularized porcine placental scaffolds from three different porcine breeds: Landrace, York and Duroc. Placental extracellular matrix (ECM) scaffolds from the three porcine breeds preserved the amnion/chorion ECM structure and the basement membrane markers laminin and collagen type IV. ECM placental scaffolds showed similar contents of collagen, elastin and lipids, and minimal differences in glycosaminoglycans content. Mechanical properties from the three breeds ECM placental scaffolds were also similar and stable for 24 months. While this study serves as preliminary characterization of porcine ECM scaffolds, future studies will determine their compatibility and suitability for tissue engineering applications.

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

BACKGROUND

Despite advancements in the surgical techniques of rotator cuff repair (RCR), there remains a high retear rate. Biological augmentation of repairs with overlaying grafts and scaffolds may enhance healing and strengthen the repair construct. This study aimed to investigate the efficacy and safety of scaffold-based (nonstructural) and overlay graft-based (structural) biological augmentation in RCR (excluding superior capsule reconstruction and bridging techniques) in both preclinical and clinical studies.

METHODS

This systematic review was performed in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, as well as guidelines outlined by The Cochrane Collaboration. A search of the PubMed, Embase, and Cochrane Library databases from 2010 until 2022 was conducted to identify studies reporting the clinical, functional, and/or patient-reported outcomes of ≥1 biological augmentation method in either animal models or humans. The methodologic quality of included primary studies was appraised using the Checklist to Evaluate a Report of a Non-pharmacological Trial (CLEAR-NPT) for randomized controlled trials and using the Methodological Index for Non-randomized Studies (MINORS) for nonrandomized studies.

RESULTS

A total of 62 studies (Level I-IV evidence) were included, comprising 47 studies reporting outcomes in animal models and 15 clinical studies. Of the 47 animal-model studies, 41 (87.2%) demonstrated biomechanical and histologic enhancement with improved RCR load to failure, stiffness, and strength. Of the 15 clinical studies, 10 (66.7%) illustrated improvement in postoperative clinical, functional, and patient-reported outcomes (eg, retear rate, radiographic thickness and footprint, and patient functional scores). No study reported a significant detriment to repair with augmentation, and all studies endorsed low complication rates. A meta-analysis of pooled retear rates demonstrated significantly lower odds of retear after treatment with biological augmentation of RCR compared with treatment with non-augmented RCR (odds ratio, 0.28; P < .00001), with low heterogeneity (I2 = 0.11).

CONCLUSIONS

Graft and scaffold augmentations have shown favorable results in both preclinical and clinical studies. Of the investigated clinical grafts and scaffolds, acellular human dermal allograft and bovine collagen demonstrate the most promising preliminary evidence in the graft and scaffold categories, respectively. With a low risk of bias, meta-analysis revealed that biological augmentation significantly lowered the odds of retear. Although further investigation is warranted, these findings suggest graft and scaffold biological augmentation of RCR to be safe.

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

PURPOSE

To perform a preclinical histologic assessment of a biphasic acellular interpositional cancellous allograft in an ovine model of rotator cuff repair (RCR) designed to better understand its safety profile and effects on tendon healing after RCR.

METHODS

Thirty skeletally mature sheep with clinically normal shoulders with an artificially created degenerative infraspinatus tendon tear were randomized to control and treatment groups. Animals were euthanized at 3 weeks, 6 weeks, and 12 weeks. After gross dissection, rotator cuff specimens were fixed with formalin and polymerized for sectioning and staining. Blinded histologic scores evaluated inflammatory cell infiltrates, signs of degradation, particulate debris, collagen arrangement, neovascularization, and enthesis qualitative measures.

RESULTS

There were no treatment specimens that exhibited histologic signs of a significant infection, inflammatory infiltrate, or foreign body reaction such as granuloma or fibrous capsule formation. Histologic scores in all categories were not significantly different at all time points, including the primary end point mean cumulative inflammatory score (control: 3.66 ± 1.21 vs treated: 4.33 ± 1.51, P = .42), when comparing the treatment and control RCR groups. In general, the degree of tendon healing and host tissue response was essentially equivalent between the 2 groups with observation of low overall levels of inflammation and progressive improvements in collagen organization, reduced tenocyte activity, and fibrocartilaginous enthesis reformation.

CONCLUSIONS

This histologic study demonstrated the use of a biphasic interpositional allograft for RCR augmentation in an ovine model does not generate an inflammatory response or foreign body reaction. Use of the biphasic interpositional allograft resulted in a histological profile that was essentially equivalent to that of a standard RCR at 3-, 6-, and 12-week postoperative timepoints. These findings suggest that a biphasic interpositional allograft is safe for further clinical investigation in humans before broader clinical application.

CLINICAL RELEVANCE

Patch augmentation of RCR is a popular technique that has shown clinical success in improving the likelihood of a successful repair in patients at elevated risk for retear. Newer augmentation technologies are being developed to address the biology at the interface between the bone and soft tissue where failure typically occurs.

The long head of the biceps tendon: a valuable tool in shoulder surgery

ANATOMY AND FUNCTION

The long head of the biceps tendon (LHBT) has different properties and characteristics that render it a valuable tool in the hands of shoulder surgeons. Its accessibility, biomechanical strength, regenerative capabilities, and biocompatibility allow it to be a valuable autologous graft for repairing and augmenting ligamentous and muscular structures in the glenohumeral joint.

SHOULDER SURGERY APPLICATIONS

Numerous applications of the LHBT have been described in the shoulder surgery literature, including augmentation of posterior-superior rotator cuff repair, augmentation of subscapularis peel repair, dynamic anterior stabilization, anterior capsule reconstruction, post-stroke stabilization, and superior capsular reconstruction. Some of these applications have been described meticulously in technical notes and case reports, whereas others may require additional research to confirm clinical benefit and efficacy.

CONCLUSION

This review examines the role of the LHBT as a source of local autograft, with biological and biomechanical properties, in aiding outcomes of complex primary and revision shoulder surgery procedures.

Revision Rotator Cuff Repair With Versus Without an Arthroscopically Inserted Onlay Bioinductive Implant in Workers' Compensation Patients

Background

The addition of onlay biological grafts to augment difficult rotator cuff repairs has shown encouraging results in a case series.

Purpose/Hypothesis

The purpose of this study was to determine whether the addition of an onlay bioinductive implant would improve repair integrity, shear wave elastographic appearance of the repaired tendon and patch, and patient-rated and/or surgeon-measured shoulder function when used in workers' compensation patients undergoing revision arthroscopic rotator cuff repair. We hypothesized that the addition of the bioinductive implant would enhance repair integrity and clinical outcomes compared with standard repair.

Study Design

Cohort study; Level of evidence, 3.

Methods

A post hoc matched-cohort study was conducted on prospectively recruited workers' compensation patients who received a bioinductive implant for revision rotator cuff repair (n = 19). The control group was selected from consecutive workers' compensation revision rotator cuff repair patients before the introduction of bioinductive implants. Then, they were matched for age and tear size (n = 32). Kaplan-Meier curves were generated to compare the primary outcome of repair integrity between groups. The secondary outcomes were to evaluate the elastographic appearance of the tendon and patch in the bioinductive implant group and to compare patient-rated and surgeon-measured shoulder function between groups preoperatively and at 1 week, 6 weeks, 3 months, and 6 months postoperatively.

Results

No major complications associated with the bioinductive implants were identified. Six months after the revision rotator cuff repair, the retear rate in the bioinductive implant group was 16% (3/19), compared with 19% (6/32) in the age- and tear size-matched control group (P = .458). At the final follow-up, the retear rate in the bioinductive implant group was 47% (9/19) at a mean of 14 months compared with 38% (12/32) at a mean of 29 months in the control group (P = .489). The shear wave elastographic stiffness of repaired tendons augmented with the bioinductive implant remained unchanged at 6 m/s from 1 week to 6 months postoperatively, which is lower than the stiffness of 10 m/s in healthy tendons. There were no significant differences in patient-rated or surgeon-measured outcomes between groups 6 months postoperatively.

Conclusion

There were no differences in repair integrity or clinical outcomes between workers' compensation patients who underwent revision arthroscopic rotator cuff repair with an onlay bioinductive implant compared to those who underwent standard revision rotator cuff repair.

A survey on the usage of decellularized tissues in orthopaedic clinical trials

Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery. Using the ClinicalTrials.gov (CTG) and the International Clinical Trials Registry Platform (ICTRP) databases, we comprehensively surveyed clinical trials of decellularized tissue use in orthopaedic surgeries registered before 1 September 2022. We evaluated the clinical results, tissue processing methods, and commercial availability of the identified products using academic literature databases and manufacturers' websites. We initially identified 4,402 clinical trials, 27 of which were eligible for inclusion and analysis, including nine shoulder surgery trials, eight knee surgery trials, two ankle surgery trials, two hand surgery trials, and six peripheral nerve graft trials. Nine of the trials were completed. We identified only one product that will be commercially available for use in knee surgery with significant mechanical load resistance. Peracetic acid and gamma irradiation were frequently used for sterilization. Despite the demand for decellularized tissue, few decellularized tissue products are currently commercially available, particularly for the knee joint. To be viable in orthopaedic surgery, decellularized tissue must exhibit biocompatibility and mechanical strength, and these requirements are challenging for the clinical application of decellularized tissue. However, the variety of available decellularized products has recently increased. Therefore, decellularized grafts may become a promising option in orthopaedic surgery.

Biceps Smash Technique: Biceps Tendon Autograft Augmentation for Arthroscopic Rotator Cuff Reconstruction

The proportion of postoperative retears after arthroscopic rotator cuff reconstruction remains constant despite advancement of suture techniques and improved anchor implants. The commonly degenerative nature of rotator cuff tears can carry the risk of compromised tissue. Several techniques have been developed to biologically enhance rotator cuff repair, and a considerable number of autologous, allogeneic, and xenogenous augmentation methods have been described. This article introduces the biceps smash technique, an arthroscopic augmentation procedure for posterosuperior rotator cuff reconstruction using an autograft patch of the long head of the biceps tendon.

Management of Massive Rotator Cuff Tears Without Arthropathy

Arthroplasty is not an optimal treatment for massive rotator cuff tears in patients who are active and without glenohumeral arthritis. Several surgical techniques have been developed for these patients, including arthroscopic rotator cuff repair with single-/double-row repair (with or without interval slides, margin convergence, graft augmentation), graft bridging, superior capsular reconstruction, tuberoplasty, and tendon transfers. Complete, tension-free, anatomic repair is ideal; however, tendon atrophy and retraction associated with massive tears often complicate repairs. All surgical treatments significantly increase patient-reported functional outcomes 1 year after intervention, with many treatments demonstrating improved mid-term and long-term outcomes. [Orthopedics. 2023;46(1):e1-e12.].

Clinical outcomes of a novel porcine small intestinal submucosa patch for full-thickness hand skin defects: a retrospective investigation

OBJECTIVE

To investigate the clinical outcomes of a novel soft tissue repair patch (porcine small intestinal submucosa patch, SIS patch) in the treatment of full-thickness hand skin defects.

METHODS

From January 2017 to July 2019, 80 patients with hand soft tissue defects, who met the inclusion criteria, were retrospectively reviewed and divided into two groups. After debridement, patients in group A were treated with the novel SIS patch to cover the wound, and patients in group B were treated with autologous skin graft. The dimensions of skin defect area and healing outcome were evaluated and recorded. Scar assessment was carried out using Scar Cosmesis Assessment and Rating Scale (SCAR scale) at the last follow-up postoperation, and the recovery of wound sensation was assessed at the same time using British Medical Research Council (BMRC) grading of sensorimotor recovery. All the data were collected and statistically analyzed.

RESULTS

A total of 80 patients were enrolled in the study with 40 patients in each group. Four patients in group A and 5 patients in group B were excluded due to wound infection and lost to follow-up. There were 36 patients in group A and 35 patients in group B finally got follow-up postoperation with mean interval of 12.75 ± 5.61 months in group A and 14.11 ± 5.42 months in group B. The dimensions of skin defect area in group A ranged from 7.5 to 87.5 cm² (mean 25.97 ± 18.66 cm²) and in group B ranged from 7.5 to 86.25 cm² (mean 33.61 ± 19.27 cm²) which have no significant difference (P > 0.05). SCAR scale results of group A and group B were 10.98 ± 0.33 and 9.49 ± 0.35, respectively, and the difference was statistically significant (P < 0.05). BMRC grading results showed 6 cases of S4, 11 cases of S3+, 5 cases of S3, 6 cases of S2, 6 cases of S1 and 2 cases of S0 in group A, and 8 cases of S4, 10 cases of S3+, 7 cases of S3, 4 cases of S2, 5 cases of S1, and 1 case of S0 in group B, which had no significant difference between them (P > 0.05).

CONCLUSIONS

The novel SIS patch is an applicable biological material in the treatment of hand skin defect, which could achieve a better cosmetic appearance of the newborn skin tissue.

A Method for Entubulating Exposed Nerve Ends Following Neurectomy Using a Porcine Extracellular Matrix Nerve Cap

Compression and irritation at the plantar aspect of the transverse intermetatarsal ligament may lead to a compressive neuropathy called Morton's neuroma. There are many treatment options for Morton's neuroma, with the most common surgical option being traction neurectomy. While there has been success in many surgical procedures, up to 35% of patients treated with traction neurectomy have recurrent pain and up to one-third of these patients have a recurrent stump neuroma. These neuromas are caused by abnormal axonal growth during regeneration, leading to an unorganized mass of fibrotic collagenous tissues, Schwann cells, and axons. More recent surgical treatments of neuromas have included nerve capping, which has been proposed to prevent painful neuroma formation by isolating the nerve end from external chemosignaling and reducing disorganized axonal outgrowth. An off-the-shelf, biocompatible porcine small intestine submucosa (pSIS) derived nerve cap with internal chambering has been investigated in a rodent study, which showed less pain sensitivity and less axonal swirling indicative of reduced likelihood of neuroma formation. Furthermore, a recent clinical study indicated that patients experienced a significant reduction in pain 3 months after Morton's neuroma excision followed by repair using a nerve cap. This article describes the surgical technique of the aforementioned clinical study to mitigate neuroma formation, where a Morton's neuroma is excised, and the remaining proximal nerve stump is inserted within a nerve cap and buried in the surrounding muscle.Level of Evidence: Level V: Expert opinion.

Novel therapy using a fish scale collagen scaffold for rotator cuff healing in rat models

BACKGROUND

Large and massive rotator cuff tears are challenging for surgeons because of postoperative complications such as repaired site retears. Recently, collagen extracted from fish scales has gained more attention because fish byproducts are considered a safer collagen source than other animal-derived scaffolds. This study aimed to evaluate the biological efficacy of tilapia scale-derived collagen scaffolds for rotator cuff repair in rat models.

METHODS

The infraspinatus tendon was resected from the greater tuberosity of Sprague-Dawley rats. In the control group, the tendon edge was sutured directly to the humeral head. In the augmentation group, the repaired site was augmented with a tilapia scale-derived collagen scaffold. Histologic examinations were performed at 2 and 4 weeks postoperatively via safranin O and immunofluorescence staining (isolectin B4 and type II collagen) in the bone-tendon junction. For mechanical analysis, the ultimate failure load of the tendon-humeral head complex was evaluated at 6 weeks postoperatively.

RESULTS

During safranin O staining, the repaired enthesis demonstrated greater proteoglycan staining in the augmentation group than in the control group at 4 weeks postoperatively. Compared to controls, the augmentation group had significantly higher vascular staining with isolectin B4 at 2 and 4 weeks postoperatively, type II collagen expression at 4 weeks postoperatively, and ultimate failure load at 6 weeks postoperatively.

CONCLUSION

Augmentation therapy using tilapia scale-derived type I collagen scaffolds promoted angiogenesis and fibrocartilage regeneration at the enthesis and provided higher mechanical strength than controls.

Decellularized Bovine Pericardial Patch Loaded With Mesenchymal Stromal Cells Enhance the Mechanical Strength and Biological Healing of Large-to-Massive Rotator Cuff Tear in a Rat Model

PURPOSE

The purpose of this study was to determine whether the addition of decellularized bovine pericardial patch loaded with mesenchymal stromal cells enhanced bone-to-tendon healing and improved the biomechanical strength of large-to-massive rotator cuff tears in a small animal model.

METHODS

Adipose-derived mesenchymal stromal cells (MSCs) from rat inguinal fat were isolated, cultured, and loaded onto decellularized bovine pericardium patches. To simulate large-to-massive tears, rats were managed with free cage activity for 6 weeks after tear creation. A total of 18 rats were randomly allocated to repair-only (control), repair with pericardial patch augmentation (patch), or repair with MSC loaded pericardial patch augmentation (patch-MSC). Each group had 6 rats (one shoulder of each rat was used for histological evaluation and another for biomechanical evaluation). MSCs seeded on the pericardial patches were traced on four shoulders from 2 other rats at 4 weeks after surgery. Histological evaluation for bone-to-tendon healing and biomechanical testing was carried out at 8 weeks after repair.

RESULTS

MSCs tagged with a green fluorescent protein were observed in the repair site 4 weeks after the repair. One shoulder each in the control and patch groups showed complete discontinuity between the bone and tendon. One shoulder in the control group showed attenuation with only a tenuous connection. Fibrocartilage and tidemark formation at the bone-to-tendon interface (P = .002) and collagen fiber density (P = .040) and orientation (P = .003) were better in the patch-MSC group than in the control or patch group. Load-to-failure in the patch-MSC and patch groups was higher than that in the control group (P = .001 and .009, respectively).

CONCLUSION

Decellularized bovine pericardial patches loaded with adipose-derived and cultured mesenchymal stromal cells enhanced healing in terms of both histology and mechanical strength at 8 weeks following rotator cuff repair in a rat model.

CLINICAL RELEVANCE

Large-to-massive rotator tears need a strategy to prevent retear and enhance healing. The addition of decellularized bovine pericardial patch loaded with MSCs can enhance bone-to-tendon healing and improve biomechanical healing of large-to-massive rotator cuff tears following repair.

Nonarthroplasty options for massive, irreparable rotator cuff tears have improvement in range of motion and patient-reported outcomes at short-term follow-up: a systematic review

PURPOSE

To compare various nonarthroplasty treatment options for massive, irreparable rotator cuff tears, including allograft bridging/augmentation, debridement, partial repair, superior capsule reconstruction (SCR), subacromial balloon spacer, and tendon transfer.

METHODS

A comprehensive search was conducted through the PubMed, MEDLINE, and EMBASE databases for all articles pertaining to nonarthroplasty treatment options for irreparable rotator cuff tears. Inclusion criteria included manuscripts published between 2009 and 2020 with at least 1 year follow-up and Level I-IV evidence. Articles were separated into six groups: debridement, arthroscopic and open repair, allograft bridging/augmentation, SCR, subacromial balloon spacer, and tendon transfer. Data points included range of motion (external rotation, abduction, forward flexion, and internal rotation), visual analog scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, Constant score, rate of revision surgery, and rate of conversion to arthroplasty.

RESULTS

A total of 83 studies and 3363 patients were included. All treatment options had statistically significant improvements in postoperative range of motion and patient-reported outcomes. Debridement had statistically significantly greater postoperative abduction and forward flexion range of motion, as well as better VAS pain scores, compared to the other treatment options. The SCR subgroup had the greatest improvement in ASES scores postoperatively. The overall revision rate was 7.2% among all surgical options, with the allograft bridging/augmentation group having the lowest rate of revision at 0-8.3%. The overall rate of conversion to arthroplasty was 7.2%, with debridement having the greatest rate of conversion at 15.4%.

CONCLUSION

All six nonarthroplasty treatment options for irreparable rotator cuff tears resulted in statistically significant improvements in range of motion and patient-reported outcomes at 1 year follow-up or more, with low rates of revision and conversion to arthroplasty. Debridement had statistically significantly greater postoperative abduction and forward flexion range of motion, as well as better VAS pain scores, compared to the other treatment options. However, these conclusions should be interpreted with caution due to the heterogeneous nature of the data, lack of prospective randomized control trials, and short-term follow-up. The findings of this study highlight the complexity of irreparable, massive rotator cuff tears, and the need for an individualized approach when treating these patients.

LEVEL OF EVIDENCE

Level IV.

Loading Mesenchymal Stem Cell-Derived Exosomes Into a Traditionally Designed Rotator Cuff Patch: A Potential Strategy to Enhance the Repair of Chronic Rotator Cuff Tear Associated With Degenerative Changes

BACKGROUND

Retraction and degenerative changes of chronic rotator cuff tears limit the healing capacity after routine surgical repair.

PURPOSE

To fabricate a mesenchymal stem cell-derived exosome (MSC-Exos) loaded patch and evaluate the effect of this patch on the activity of rabbit tenocytes in vitro and on the repair of chronic rotator cuff tears associated with degenerative changes in vivo.

STUDY DESIGN

Controlled laboratory study.

METHODS

The MSC-Exos loaded patch was fabricated using a dynamic wet-spinning system. In the in vitro studies, the proliferation and migration activities of tenocytes were evaluated by culturing tenocytes with saline, a fiber-aligned patch, or an MSC-Exos loaded patch. In the in vivo studies, a rabbit model of chronic rotator cuff tear was established and directly repaired, repaired with fiber-aligned patch augmentation (RFPA group), and repaired with MSC-Exos loaded patch augmentation (REPA group). Histological and biomechanical analyses were performed at 4, 8, and 12 weeks after surgery.

RESULTS

An MSC-Exos loaded patch with inner aligned fibers, a loose microstructure, and reliable initial strength was fabricated using a dynamic wet-spinning system. The MSC-Exos loaded patch significantly promoted tenocyte proliferation and migration activities in vitro. In vivo, the REPA group exhibited significantly higher tendon maturing scores at 8 and 12 weeks after surgery compared with both the control and the RFPA groups. Fatty infiltration was significantly reduced in the REPA group at 4, 8, and 12 weeks compared with both the control and the RFPA groups. Biomechanical properties, including load to failure and stress, were also significantly improved at 12 weeks in the REPA group compared with both the control and the RFPA groups.

CONCLUSION

Results in the present study suggested that an MSC-Exos loaded patch was able to enhance the repair of a chronic rotator cuff tear by providing mechanical support and minimizing degeneration.

CLINICAL RELEVANCE

This work supported the idea that loading bioactive MSC-Exos into a traditionally designed rotator cuff patch might exert a better effect on the repair of chronic rotator cuff tears than augmented patch repair alone.

Clinical outcomes and structural integrity rate of arthroscopic augmented rotator cuff repairs using extracellular porcine matrix patch

BACKGROUND

Structural failure rate in rotator cuff repairs is still high. The purpose of the study is to assess the structural integrity of a series of augmented rotator cuff repairs with porcine matrix patch and report the functional outcomes.

METHODS

Between 2014 and 2017, 44 consecutive patients underwent arthroscopic double-row repair of medium to massive rotator cuff tears with extracellular porcine dermal matrix augmentation. At one-year follow-up, magnetic resonance imaging scan was performed to assess the integrity of the repair. Oxford Shoulder Score (OSS), Constant Score (CS) and Visual Analogue Scale pain score, together with range of motion were used to assess patients.

RESULTS

Patients mean age was 68 (53-82); mean follow-up was 17.2 (12-24) months. On magnetic resonance imaging scans, seven rotator cuff repair failures (15.9%) were observed: tear size was an independent predictor of re-rupture at one-year follow-up. Clinical scores showed a statistically significant improvement at three months and until final follow-up (p< 0.001). No complications occurred.

CONCLUSION

Observed structural failure rate of 15.9% is lower than those reported in the literature for standard rotator cuff repair of medium to massive tears in similar cohorts to ours. Extracellular matrix augmentation for rotator cuff repair was shown to be a safe and reliable support to the repairs and patients recovered good shoulder function.Level of Evidence: Level IV.

Graft Augmentation of Repairable Rotator Cuff Tears: An Algorithmic Approach Based on Healing Rates

We provide our algorithm for tissue augmentation of rotator cuff repairs based on the current available evidence regarding rotator cuff healing. A variety of factors are associated with healing following rotator cuff repair. Increasing tear size and retraction as well as severe fatty degeneration have been associated with worsening rates of tendon healing. Given the correlation between tendon healing and postoperative outcomes, it is important to identify patients at high risk for failure and to modify their treatment accordingly to minimize the risk of early biomechanical failure and maximize the potential for structural healing. One approach that may be used to improve healing is tissue augmentation. Tissue augmentation is the use of tissue patches and scaffolds to provide rotator cuff reinforcement. Surgical management for rotator cuff tears (RCTs) continues to be a challenging task in orthopaedic surgery today. Appropriate treatment measures require an in depth understanding and consideration of the patient's prognostic factors such as age, fatty infiltration of the rotator cuff muscles, bone mineral density, rotator cuff retraction, anteroposterior tear size, work activity, and degenerative changes of the joint. Using these factors within the Rotator Cuff Healing Index, we can determine a patient's surgical treatment that will yield the maximum healing rate. For nonarthritic RCTs, joint-preserving strategies should be first-line treatment options. For young, active patients with a reparable RCT and minimal fatty infiltration, a complete repair can be effective. For young patients with irreparable RCTs, superior capsular reconstructions, and tendon transfers are viable options. For elderly patients with low work activity, an irreparable RCT and significant fatty infiltration, a partial repair with or without graft augmentation can be attempted if minimal to no arthritic changes are seen. LEVEL OF EVIDENCE: Level V, expert opinion.

Bioinductive collagen implants facilitate tendon regeneration in rotator cuff tears

Purpose

To evaluate the clinical outcomes, MRI imaging and histological characteristics of biopsy samples of the tendon from patients in whom rotator cuff repair was previously performed with a bioinductive type I bovine collagen implants.

Methods

Prospective study of 30 patients with partial or complete rotator cuff tears who underwent arthroscopic repair and augmentation with a resorbable type I bovine collagen implant. Preoperatively and at 6 and 12 months after surgery, the VAS, ASES and Constant-Murley scores were evaluated and an MRI study was performed. At 6 months, biopsies of the resulting tissue were obtained and examined histologically.

Results

Patients experienced statistically significant and sustained improvement from baseline for all scores and the mean tendon thickness increased by 1.84 mm. Magnetic resonance imaging evidence of complete healing was found in 27 patients and a considerable reduction in defect size, greater than 50%, was shown in 3. In all samples obtained, the new tissue generated had the histological appearance of a tendon, and was indistinguishable from the native tendon. There was no evidence of any remaining collagen implant.

Conclusions

Biopsies of tissue formed from bioinductive type I bovine collagen implants showed, six months after surgery, the generation of a neotendon indistinguishable from the native one. Histology and MRI imaging, revealed complete integration of the implant and absence of inflammatory or foreign body reactions. The clinical parameters, thickness and MRI signal of the tendon improved significantly at 6 months, regardless of the type and size of the tear, and remained unchanged until 12 months.

Level of evidence

Level IV, case series.

Rotator cuff repair protected with subacromial balloon spacer shows a low rate of non-healing

PURPOSE

The purpose of this study was to evaluate clinical outcomes and tendon integrity on magnetic resonance imaging (MRI) of chronic posterosuperior rotator cuff tears treated with single-row tensionless repair and subacromial balloon spacer as protection with a minimum follow-up of 2 years. The hypothesis of this study was that this procedure would have acceptable clinical outcomes and tendon-healing rate without increased complications.

METHODS

This is a retrospective study of patients with chronic posterosuperior rotator cuff tears repaired with a single-row technique protected with a subacromial balloon device. Patients were followed up for a minimum of 2 years. Clinical outcomes were evaluated with American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and Numerical Rating Scale (NRS) for pain. MRI study was obtained likewise after at least 2 years to assess tendon-healing rate. Statistical comparison was performed between pre-operative and at least 2-year clinical and imaging follow-up.

RESULTS

Thirty-two patients were included in the study with a mean follow-up of 27 ± 7 (range 24-48). The mean age of this cohort was 58 ± 6 (range 41-66) including 15 males and 17 females. The tear size was on average 2.3 cm (range 2-4) and a mean of 2.1 triple-loaded anchors were used (range 2-3). The ASES score significantly increased from a mean of 39 ± 12 points to a mean of 89 ± 12 at the final follow-up (P < 0.001). Similarly, pain significantly reduced from a mean pre-operative NRS of 6.8 ± 1.4 to 0.8 ± 1.5 at the final follow-up (P < 0.001). MRI scans showed that repair occurred in 26 patients (81.3%). Significant higher ASES score was reached at final follow-up in patients with a "healed" (Sugaya I-III) tendon when compared to patients with an evidence of tendon discontinuity on MRI study (Sugaya IV-V), 93 ± 9 and 74 ± 13, respectively (P < 0.001).

CONCLUSIONS

Arthroscopic repair of chronic posterosuperior rotator cuff tears using a single-row tensionless repair and subacromial spacer as protection resulted in an 81.3% of tendon integrity at a mean follow-up of 27 months. Clinical outcomes and pain scores significantly improved without severe complications reported after a minimum follow-up of 2 years.

LEVEL OF EVIDENCE

III.

Advances in Regenerative Sports Medicine Research

Regenerative sports medicine aims to address sports and aging-related conditions in the locomotor system using techniques that induce tissue regeneration. It also involves the treatment of meniscus and ligament injuries in the knee, Achilles’ tendon ruptures, rotator cuff tears, and cartilage and bone defects in various joints, as well as the regeneration of tendon–bone and cartilage–bone interfaces. There has been considerable progress in this field in recent years, resulting in promising steps toward the development of improved treatments as well as the identification of conundrums that require further targeted research. In this review the regeneration techniques currently considered optimal for each area of regenerative sports medicine have been reviewed and the time required for feasible clinical translation has been assessed. This review also provides insights into the direction of future efforts to minimize the gap between basic research and clinical applications.

Co-administration of platelet-rich plasma and small intestinal submucosa is more beneficial than their individual use in promoting acute skin wound healing

Background

Acute skin wounds may compromise the skin barrier, posing a risk of infection. Small intestinal submucosa (SIS) is widely used to treat acute and chronic wounds. However, the efficacy of SIS to accelerate wound healing still needs to be improved to meet clinical demands. To tackle this problem, platelet-rich plasma (PRP) is used due to its potency to promote proliferation, migration and adhesion of target cells. In this study, we applied PRP and SIS to skin wounds to explore their effects on wound healing by evaluating re-epithelialization, collagen production, angiogenesis and the inflammatory response.

Methods

A 1 × 1-cm full-thickness skin defect was established in mice. Sixty mice were divided into four treatment groups: PRP + SIS, PRP, SIS and control. On days 3, 5, 7, 10 and 14 post-surgery, tissue specimens were harvested. Haematoxylin and eosin, Masson's trichrome, immunohistochemical and immunofluorescence double staining were used to visualize epidermal thickness, collagen and vascular regeneration and inflammation.

Results

Wound contraction in the PRP and PRP + SIS groups was significantly greater, compared with the other groups, on days 3 and 5 post-surgery. A histological analysis showed higher collagen expression in the PRP and PRP + SIS groups on day 7, which was associated with a thicker epidermal layer on day 14. In addition, immunohistochemical staining showed that CD31-positive blood vessels and vascular endothelial growth factor expression in the PRP + SIS and PRP groups were significantly higher, compared with the control group. Furthermore, immunofluorescence double staining showed that the number of M1 and M2 macrophages in the PRP + SIS and PRP groups was higher, compared with the control and SIS groups alone, on day 3. However, on day 7, the number of M1 macrophages dramatically decreased in the PRP + SIS and PRP groups. The ratio of M2 to M1 macrophages in the PRP + SIS and PRP groups was 3.97 and 2.93 times that of the control group and 4.56 and 3.37 times that of the SIS group, respectively.

Conclusion

Co-administration of SIS and PRP has a better effect on promoting angiogenesis, re-epithelialization and collagen regeneration in managing acute wound healing than either agent alone.

Clinical effect of arthroscopic long head of biceps transfer and tenodesis on irreparable rotator cuff tear

Objective

To explore the clinical effect of arthroscopic long head of biceps transfer and tenodesis for on irreparable rotator cuff tear.

Methods

A total of 18 patients with irreparable rotator cuff tear who were treated in the Dongfang Hospital Affiliated to Tongji University School of Medicine from April 2018 to March 2020 were included in this study. They all underwent arthroscopic long head of biceps transfer and tenodesis. Shoulder joint motions (forward flexion, abduction, and external rotation angle) and magnetic resonance imaging (MRI) were performed. Moreover, visual analogue scale (VAS) and university of California Los Angeles (UCLA) score were conducted during follow-up.

Results

Preoperative symptoms lasted from 3 to 16 months, with an average duration of 10 months. All patients healed in the first stage without obvious complications were included. All patients were followed up for 4 to 14 months after the surgery, with an average duration of 11.1 months. The range of shoulder joint motions, including forward flexion (80.52° ± 31.19° vs. 149.47° ± 28.36°), abduction (65.13° ± 37.59° vs. 152.46° ± 28.64°) and lateral rotation (30.17° ± 15.15° vs. 71.49° ± 11.42°) was significantly improved after operation (P < 0.05). The VAS score was notably decreased after operation (8.46 ± 0.80 vs. 1.55 ± 0.70), but the UCLA score was markedly increased (15.27 ± 2.89 vs. 31.17 ± 2.36). MRI imaging showed that 15 patients had good tissue healing, with a healing rate of 83.3% (15/18).

Conclusion

Arthroscopy of the biceps long head tendon transposition can significantly relieve pain in patients with large rotator cuff tears, improve joint mobility, and restore joint function.

Benefits of Patch Augmentation on Rotator Cuff Repair: A Systematic Review and Meta-analysis

Background:

Despite technological advances, the overall retear rate on rotator cuff repair is still high. Patches have shown significant reduction in retear rate and pain scores; however, this is not a universal finding and conflicting results have been shown among functional shoulder scales.

Purpose:

To analyze previous controlled trials of the literature to bring a consensus about the effectiveness of patch use on rotator cuff repair.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

The search was conducted in PubMed, Web of Science, EMBASE, Scopus, and Cochrane in April 2020. The results of rotator cuff repair with patch augmentation versus without augmentation (control) were compared through odds ratio (OR), raw mean difference (RMD), and standardized mean difference (SMD) of retear rate; functional shoulder scales; strength; and range of motion (ROM).

Results:

Of 733 initial studies, 7 of them met the criteria to be included in the analysis. Compared with the control group, the patch augmentation group had a significantly lower retear rate (OR, 0.32 [95% CI, 0.18 to 0.55]; P < .001), lower pain (SMD, –0.42 [–0.71 to –0.12]; P < .01), a higher University of California Los Angeles Shoulder Rating Scale (RMD, 0.87 [0.15 to 1.60], P = .017), and a trend toward higher strength (SMD, 0.95 [–0.03 to 1.94], P = .05) and lower forward elevation ROM (RMD, –10.50 [–21.86 to 0.67]; P = .06), while no changes were noted for other functional scales or for internal and external rotation ROM.

Conclusion:

The results point to benefits of patch augmentation in rotator cuff repair, particularly a reduction in retear rate. More interventional studies with better methodological quality should be conducted to confirm the results of this initial review.

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

Background

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

Methods

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

Results

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

Conclusion

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

The Translational potential of this article

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

Artificial intelligence for MRI diagnosis of joints: a scoping review of the current state-of-the-art of deep learning-based approaches

Deep learning-based MRI diagnosis of internal joint derangement is an emerging field of artificial intelligence, which offers many exciting possibilities for musculoskeletal radiology. A variety of investigational deep learning algorithms have been developed to detect anterior cruciate ligament tears, meniscus tears, and rotator cuff disorders. Additional deep learning-based MRI algorithms have been investigated to detect Achilles tendon tears, recurrence prediction of musculoskeletal neoplasms, and complex segmentation of nerves, bones, and muscles. Proof-of-concept studies suggest that deep learning algorithms may achieve similar diagnostic performances when compared to human readers in meta-analyses; however, musculoskeletal radiologists outperformed most deep learning algorithms in studies including a direct comparison. Earlier investigations and developments of deep learning algorithms focused on the binary classification of the presence or absence of an abnormality, whereas more advanced deep learning algorithms start to include features for characterization and severity grading. While many studies have focused on comparing deep learning algorithms against human readers, there is a paucity of data on the performance differences of radiologists interpreting musculoskeletal MRI studies without and with artificial intelligence support. Similarly, studies demonstrating the generalizability and clinical applicability of deep learning algorithms using realistic clinical settings with workflow-integrated deep learning algorithms are sparse. Contingent upon future studies showing the clinical utility of deep learning algorithms, artificial intelligence may eventually translate into clinical practice to assist detection and characterization of various conditions on musculoskeletal MRI exams.

Evaluation of patches for rotator cuff repair: A systematic review and meta-analysis based on animal studies

Based on the published animal studies, we systematically evaluated the outcomes of various materials for rotator cuff repair in animal models and the potentials of their clinical translation. 74 animal studies were finally included, of which naturally derived biomaterials were applied the most widely (50.0%), rats were the most commonly used animal model (47.0%), and autologous tissue demonstrated the best outcomes in all animal models. The biomechanical properties of naturally derived biomaterials (maximum failure load: WMD 18.68 [95%CI 7.71–29.66]; P = 0.001, and stiffness: WMD 1.30 [95%CI 0.01–2.60]; P = 0.048) was statistically significant in the rabbit model. The rabbit model showed better outcomes even though the injury was severer compared with the rat model.

•

The first systematic review & meta-analysis on rotator cuff patch materials.

•

The quality of evidence for repair of rotator cuff injury with patch materials is very low.

•

Evidence-based research is an effective way to study patch materials.

Decellularization of Small Intestinal Submucosa

Small intestinal submucosa (SIS) is the most studied extracellular matrix (ECM) for repair and regeneration of different organs and tissues. Promising results of SIS-ECM as a vascular graft, led scientists to examine its applicability for repairing other tissues. Overall results indicated that SIS grafts induce tissue regeneration and remodeling to almost native condition. Investigating immunomodulatory effects of SIS is another interesting field of research. SIS can be utilized in different forms for multiple clinical and experimental studies. The aim of this chapter is to investigate the decellularization process of SIS and its common clinical application.

Retear rates after rotator cuff surgery: a systematic review and meta-analysis

Background

Rotator cuff retear (RCR) is one of the main postoperative drawbacks. RCR can be considered a multifactorial issue, which causes are related either to biological than biomechanical factors. The aim of this study was to define the incidence of RCR after surgical treatment at different time points and to identify the main factors influencing the postoperative rotator cuff (RC) healing.

Methods

A systematic review and meta-analysis were performed following the PRISMA guidelines. A comprehensive search of the literature was carried out in July 2020, using PubMed and Cochrane Library databases. Only level 1 and 2 clinical evidence studies were included. Studies were included if patients with preoperative repairable full-thickness RC tears were treated surgically, and if studies reported postoperative RCR confirmed by imaging diagnostic. The association between timing of retear and follow-up time points were investigated using an inverse-variance method of pooling data. A subgroup meta-analysis was performed using the DerSimonian and Laird method for the estimation of the between-study variance, i.e., τ². The association between retear rate after surgery and patients’ age, preoperative tear size, fatty infiltration, postoperative rehabilitation protocol, surgical techniques, and RC repairs was determined by expressing the effect measure in terms of odds ratio (OR) with 95% confidence interval (CI). The Mantel-Haenszel method with 95% CIs was used.

Results

Thirty-one articles were included in this study. The percentage of RCR after surgery was 15% at 3 months follow-up, 21% at 3–6 months follow-up, 16% at 6–12 months follow-up, 21% at 12–24 months follow-up, 16% at follow-up longer than 24 months. The main factors influencing RC healing are both patient-related (i.e., age, larger tear size, fatty infiltration) and not patient-related (i.e., postoperative rehabilitation protocol, surgical techniques, and procedures).

Conclusions

Postoperative RC healing is influenced by patient-related and non-patient-related factors. Further high-level clinical studies are needed to provide highly relevant clinical results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04634-6.

Findings from the patch augmented rotator cuff surgery (PARCS) feasibility study

Background

A rotator cuff tear is a common disabling shoulder problem. Symptoms include pain, weakness, lack of 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. The use of patch augmentation to provide support to the healing process and improve patient outcomes holds new promise. Different materials (e.g. human/animal skin or intestine tissue, and completely synthetic materials) and processes (e.g. woven or a mesh) have been used to produce patches. However, clinical evidence on their use is limited. The patch augmented rotator cuff surgery (PARCS) feasibility study aimed to determine the design of a definitive randomised controlled trial (RCT) 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

A mixed methods feasibility study of conducing a subsequent RCT. The project involved six stages: a systematic review of clinical evidence; a survey of the British Elbow and Shoulder Society’s (BESS) surgical membership; a survey of surgeon trialists; focus groups and interviews with stakeholders; a two-round Delphi study administered via online questionnaires and a 2-day consensus meeting.

Results

The BESS surgeons’ survey identified a variety of patches in use (105 (21%) responses received). Twenty-four surgeons (77%) completed the trialist survey relating to trial design. Four focus groups were conducted involving 24 stakeholders. Twenty-nine (67% of invited) individuals took part in the Delphi. Differing views were held on a number of aspects including the appropriate patient population for trial participation. Agreement on the key research questions and the outline of two potential RCTs were achieved through the Delphi study and the consensus meeting.

Conclusions

Randomised comparisons of on-lay patch use for completed rotator cuff repairs, and bridging patch use for partial rotator cuff repairs were identified as areas for further research. The value of an observational study to assess safety concerns of patch use was also highlighted. The main limitation was that the findings were influenced by the participants, who might not necessarily reflect all stakeholders.

Interposition grafting for irreparable rotator cuff tears: Systematic review and specialist practice report

The treatment of symptomatic irreparable rotator cuff tears poses significant challenges to both patients and shoulder surgeons. Although reverse shoulder arthroplasty provides reliably good outcomes in the elderly, it is not a good option in younger patients. Various surgical techniques have been proposed for the treatment of irreparable rotator cuff tears; however, no gold standard currently exists. Interposition grafting is used when the rotator cuff cannot be fully repaired onto its footprint, and the remaining defect is bridged with either an allograft, autograft, xenograft or a synthetic graft. This review aims to present the literature on the use of various interposition grafts and techniques to treat large or massive irreparable rotator cuff tears and provide a specialist practice report.

"Current concepts and expert practice report: Augmentation of rotator cuff repairs"

Rotator cuff tears are common shoulder injuries expected to increase with the growth of the aging population. Although a small subset of patients with low functional demands can be treated nonoperatively, surgical intervention is a cost-effective solution, which can restore shoulder function and help patients return to activity sooner. While multiple surgical options are available, rotator cuff repair is a highly utilized procedure with varying success. Due to a large proportion of rotator cuff repairs still failing to completely heal, this procedure requires careful planning to achieve anatomical and biomechanically stability. New technology and techniques are being explored to help increase the success of rotator cuff repairs with an increasing focus on augmentation. The current article gives a brief overview of pertinent anatomy, treatment options, and challenges in healing of rotator cuff repairs. Thereafter, the merits of different types of rotator cuff repair augmentation available will be discussed as well as the authors' experience in utilizing biologic augmentation and surgical technique.

Trends in rotator cuff surgery: Research through the decades

INTRODUCTION

The aim of this study is to analyse the most cited articles in rotator cuff surgery and identify trends in topics by decade to see which areas may still need further investigation.

METHODS

Journal Citation Index was searched to find articles using the search terms pertaining to "rotator cuff repair". All articles were ranked according to most cited, and then further analysed to find most cited articles in each decade. Articles were grouped into topics to find themes for each decade.

RESULTS

All the most cited articles were published in 6 orthopaedic journals. Only 4 of the top 30 citations provided level I evidence. Each decade's most cited articles seemed to fit into a broad topic, with platelet-rich plasma and biologic augmentation being prominent in the last decade.

CONCLUSION

There are still many unanswered questions in rotator cuff surgery, but this may be because success of certain treatment options are highly dependent on patient selection. Despite growing numbers of articles being published on rotator cuff repairs, the level of evidence remains low. Larger, collaborative projects may help in answering the common dilemmas that still face shoulder surgeons.

Acellular Cartilage Repair Technique Based on Ultrapurified Alginate Gel Implantation for Advanced Capitellar Osteochondritis Dissecans

Background:

One of the most important limitations of osteochondral autograft transplant is the adverse effect on donor sites in the knee. Ultrapurified alginate (UPAL) gel is a novel biomaterial that enhances hyaline-like cartilage repair for articular defects. To avoid the need for knee cartilage autografting when treating osteochondritis dissecans (OCD) of the capitellum, we developed a surgical procedure involving a bone marrow stimulation technique (BMST) augmented by implantation of UPAL gel.

Hypothesis:

BMST augmented by UPAL gel implantation improves the cartilage repair capacity and provides satisfactory clinical outcomes in OCD of the capitellum.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 5 athletes with advanced capitellar OCD in the dominant elbow underwent BMST augmented by implantation of UPAL gel. The osteochondral defects were filled with UPAL gel after BMST. At a mean follow-up of 97 weeks, all patients were evaluated clinically and radiographically.

Results:

At final follow-up, all 5 patients had returned to competitive-level sports, and 4 patients were free from elbow pain. The mean Timmerman-Andrews score significantly improved from 100 to 194 points. Radiographically, all patients exhibited graft incorporation and a normal contour of the subchondral cortex. Magnetic resonance imaging showed that the preoperative heterogeneity of the lesion had disappeared, and the signal intensity had returned to normal. Arthroscopic examinations consistently exhibited improvement in the International Cartilage Regeneration and Joint Preservation Society (ICRS) grade of lesions from 3 or 4 to 1 or 2 in 4 patients at 85 weeks postoperatively. Histologic analysis of biopsy specimens revealed an average total ICRS Visual Assessment Scale II histologic score of 1060.

Conclusion:

The acellular cartilage repair technique using UPAL gel for advanced capitellar OCD provided satisfactory clinical and radiographic results. The present results suggest that this novel technique is a useful, minimally invasive approach for treating cartilaginous lesions in athletes.

Patch augmentation surgery for rotator cuff repair: the PARCS mixed-methods feasibility study

BACKGROUND

A rotator cuff tear is a common, disabling shoulder problem. Symptoms may 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 need to improve the outcome of rotator cuff surgery, and the use of patch augmentation (on-lay or bridging) to provide support to the healing process and improve patient outcomes holds promise. Patches have been made using different materials (e.g. human/animal skin or tissue and synthetic materials) and processes (e.g. woven or mesh).

OBJECTIVES

The aim of the Patch Augmented Rotator Cuff Surgery (PARCS) feasibility study was to determine the design of a definitive randomised controlled trial assessing the clinical effectiveness and cost-effectiveness of a patch to augment surgical repair of the rotator cuff that is both acceptable to stakeholders and feasible.

DESIGN

A mixed-methods feasibility study of a randomised controlled trial.

DATA SOURCES

MEDLINE, EMBASE and the Cochrane Library databases were searched between April 2006 and August 2018.

METHODS

The project involved six stages: a systematic review of clinical evidence, a survey of the British Elbow and Shoulder Society's surgical membership, a survey of surgeon triallists, focus groups and interviews with stakeholders, a two-round Delphi study administered via online questionnaires and a 2-day consensus meeting. The various stakeholders (including patients, surgeons and industry representatives) were involved in stages 2-6.

RESULTS

The systematic review comprised 52 studies; only 15 were comparative and, of these, 11 were observational (search conducted in August 2018). These studies were typically small (median number of participants 26, range 5-152 participants). There was some evidence to support the use of patches, although most comparative studies were at a serious risk of bias. Little to no published clinical evidence was available for a number of patches in clinical use. The membership survey of British Elbow and Shoulder surgeons [105 (21%) responses received] identified a variety of patches in use. Twenty-four surgeons (77%) completed the triallist survey relating to trial design. Four focus groups were conducted, involving 24 stakeholders. Differing views were held on a number of aspects of trial design, including the appropriate patient population (e.g. patient age) to participate. Agreement on the key research questions and the outline of two potential randomised controlled trials were achieved through the Delphi study [29 (67%)] and the consensus meeting that 22 participants attended.

LIMITATIONS

The main limitation was that the findings were influenced by the participants, who are not necessarily representative of the views of the relevant stakeholder groups.

CONCLUSION

The need for further clinical studies was clear, particularly given the range and number of different patches available.

FUTURE WORK

Randomised comparisons of on-lay patch use for completed rotator cuff repairs and bridging patch use for partial rotator cuff repairs were identified as areas for further research. The value of an observational study to assess safety concerns of patch use was also highlighted. These elements are included in the trial designs proposed in this study.

STUDY REGISTRATION

The systematic review is registered as PROSPERO CRD42017057908.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 13. See the NIHR Journals Library website for further project information.

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.