Human dermal matrix scaffold augmentation for large and massive rotator cuff repairs: preliminary clinical and MRI results at 1-year follow-up

Clinical and Radiologic Outcomes of Augmented Partial Repair with Acellular Dermal Allograft and Superior Capsular Reconstruction in Massive Rotator Cuff Tears: 2-Year Follow-Up

Background/Objectives: To evaluate the clinical and radiologic outcomes of arthroscopic augmented partial repair (APR) with acellular dermal matrix versus arthroscopic superior capsular reconstruction (SCR) in massive rotator cuff tears. Methods: The study included a total of 49 patients with massive rotator cuff tears who underwent arthroscopic APR (26 patients) and SCR (23 patients) between March 2018 and June 2021. Clinical scores, visual analog scores, and range of motion were collected preoperatively and postoperatively until the last follow-up. Preoperative and postoperative simple radiographs were evaluated for arthropathic changes and acromiohumeral distances (AHDs). Magnetic resonance imaging was performed to assess the integrity of repaired structures at 12 months postoperatively. Results: The average age of patients was 63.9 years (range 53-74 years), and the mean clinical follow-up period was 2.6 years (range 2.1-2.9). The average UCLA scores improved from 18.0 to 33.2 and from 16.3 to 32.1 in APR and SCR groups at the last follow-up, respectively. For the ranges of motion, the APR group consistently showed better external rotation ranges from the postoperative 6th month until the last follow-up (p < 0.05), and the APR group revealed better ranges of motion in forward flexion, abduction, and external rotation compared to the SCR group (p < 0.05). Postoperative AHD showed better improvement in the APR group than the SCR group (p < 0.05). Re-tears were found in two patients in each group (p > 0.05). Conclusions: Both APR and SCR groups showed comparable improvement in clinical outcomes in massive rotator cuff tears, while the APR group showed statistically significant improvement in the range of motion compared to the SCR group, especially for external rotations.

Dermal Graft Thickness Over 2 mm and Grafts Oriented Parallel to Skin Tension Lines Increased Graft Strength and Suture Retention: A Biomechanical Study

PURPOSE

To assess the variability in graft biomechanical properties of an acellular human dermal matrix patch.

METHODS

A total of 22 strips obtained from 6 separate graft specimens (AlloPatch HD) were tested. Load elongation properties after cyclic loading, including ultimate load at break, energy at break, and extension at break, were tested and compared by graft thickness. Suture pull-out testing using a simple vertical stitch suture retention test was performed.

RESULTS

There was a significant, strong positive correlation between graft thickness and ultimate load to failure, energy at break, and extension at break (P < .01). The association between direction of graft in relation to skin tension lines and ultimate load to failure was also significant (P < .034). The difference in ultimate load to failure from the extremes of graft thickness in this study (1.1 mm vs 3.2 mm) was almost 4-fold (104 N/mm2 vs 402 N/mm2). The suture pull-out testing of 10 dermal graft test strips showed that once the graft thickness reached a threshold thickness of 2 mm, the mode of failure changed from cutting through the graft vertically to tearing the graft diagonally.

CONCLUSIONS

The tested dermal allograft patch shows great variability in thickness within and between individual patches. This study has revealed that grafts thicker than 2 mm and those used in parallel to skin tension lines exhibit a higher ultimate load to failure. Furthermore, graft thickness over 2 mm influenced the method of suture failure.

CLINICAL RELEVANCE

Caution should be exercised when using grafts less than 2 mm due to lower ultimate load to failure and suture pull-out. Marking the patches in accordance with skin tension lines would help determine the ideal orientation of insertion.

One Step Double Augmentation with Human Dermis Allograft and Homologous PRP in Misdiagnosed and or Chronic Achilles Tendon Ruptures

OBJECTIVE

Misdiagnosed/chronic Achilles tendon injuries are rare and disabling for patients. The surgical treatment of these rare injuries aims to ensure the tendon heals mechanically and biologically. This is the prerequisite for a good clinical and functional outcome and reduces recurrences. The main aim of the study is to present a surgical technique that has proven to be original, reproducible, and capable of guaranteeing solid tendon repair and optimal tissue regeneration.

METHODS

We treated five patients, four males and one female, with the one-step double augmentation technique. All patients of this study complained of pain, but above all severe functional limitation that Achilles tendon injury had been causing for more than a month. In this study, we widely described the surgical technique, original and not found in the literature, which provides a biological graft (allograft of decellularized dermis) and homologous, thrombin-activated, platelet-rich plasma (H-PRP) in a single step. Surgical approach, always used by the first author, respected predefined steps: careful dissection and preparation of the peritendinous tissues from suture to the end of the procedure, tenorrhaphy, and augmentation with allopatch to obtain a mechanically effective repair to avoid recurrences, and finally "biological" augmentation with a unit of homologous, thrombin activated, PRP. We offered to all patients a regenerative rehabilitation program post-operatively.

RESULTS

All patients were evaluated clinically (functional clinical tests and questionnaires) and instrumentally (elastic-sonography and perfusion MRI). The obtained results have been evaluated at a minimum follow-up of 18 months and a maximum of 24 months. In all patients pain was resolved, and district function and kinetic chains improved with resumption of daily activities, work, and sports.

CONCLUSION

The present study confirmed the regenerative potential of decellularized dermis allograft and PRP (homologous and thrombin-activated). The same approach can also be exploited in cases of severe tendon destructuring and limited "intrinsic" regenerative potential at any age. The proposed one-step surgical technique of a double augmentation therefore appears useful, safe, reproducible, and applicable in all chronic tendon lesions with low regenerative potential.

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.

The First Use of Human-Derived ADM in Prepectoral Direct-to-Implant Breast Reconstruction after Skin-Reducing Mastectomy

INTRODUCTION

Large and ptotic breasts always represented a great reconstructive challenge for plastic surgeons. In order to deal with these patients, we started performing Wise-pattern skin-reducing mastectomies (SRM) followed by direct-to-implant breast reconstructions (DTI-BR) in the prepectoral space where the implants were covered with the autologous adipo-dermal flap and a human acellular dermal matrix called MODA.

MATERIALS AND METHOD

We retrospectively reviewed all patients that underwent Wise-pattern SRM followed by MODA-assisted, prepectoral, DTI-BR between January 2017 and November 2019 at our Institution. Inclusion criteria were large ptotic breast and pinch test >2cm, while exclusion criteria were smoking >10 cigarettes/day, history of prior radiotherapy, patients supposedly requiring breast implants bigger than 550cc or post-mastectomy radiotherapy. Patients' data were collected through their electronic medical records. Both short- and long-term outcomes were reported.

RESULTS

Seventeen patients underwent Wise-pattern SRM followed by MODA-assisted, prepectoral, DTI-BR for a total of twenty-one breast reconstruction and fourteen matching procedures. Mean follow-up was 13.4 months (SD= ±3.67). No major complication was reported. Three (14.3%) reconstructed breasts had minor complications: 2 (9.5%) minimal (<1cm²) wound dehiscence and 1 (4.8%) de-epithelization of the skin at the T junction that were treated conservatively. Drainages gave mean output of 410.59 ml (SD= ±214.83) and were kept in place on average for 8.59 days (SD= ±3.45).

CONCLUSION

Few are the reports in the literature regarding DTI-BR following SRM and even fewer are those where BR was performed in the prepectoral space. Our work demonstrated the safety of prepectoral DTI-BR following SRM in selected patients in accordance with the "conservative reconstruction" principles. Furthermore, we confirmed the reliability of MODA in accordance with previously published works.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A New Treatment for the Reconstruction of the Medial Compartment of the Ankle: The Combined Use of Biological Materials

Fractures, especially if articular and periarticular, are frequently associated to functional and clinical disabling outcomes and chronic pain. In particular, the injuries with loss of bone, ligament, and/or tendon tissue in which the full recovery of the wound area is not obtained are the worst anatomical/pathological conditions to heal. In this study, three different biological materials were used as regenerative approaches to rebuild the medial malleolus fracture of the ankle in which loss of bone, ligament, and tendon tissue occur. In particular, the morselized human bone tissue was combined with the human dermis decellularized, both augmented with homologous platelet-rich plasma. The magnetic resonance imaging study with contrast at the follow-up showed a signal compatible with vascularization of the tissue without sign of degeneration. Our new regenerative approach in which different biological materials were combined together showed a good choice of treatment for the reconstruction of not repairable outcome of a fracture.

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.

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.

The Role of Scaffolds in Tendon Tissue Engineering

Tendons are unique forms of connective tissue aiming to transmit the mechanical force of muscle contraction to the bones. Tendon injury may be due to direct trauma or might be secondary to overuse injury and age-related degeneration, leading to inflammation, weakening and subsequent rupture. Current traditional treatment strategies focus on pain relief, reduction of the inflammation and functional restoration. Tendon repair surgery can be performed in people with tendon injuries to restore the tendon's function, with re-rupture being the main potential complication. Novel therapeutic approaches that address the underlying pathology of the disease is warranted. Scaffolds represent a promising solution to the challenges associated with tendon tissue engineering. The ideal scaffold for tendon tissue engineering needs to exhibit physiologically relevant mechanical properties and to facilitate functional graft integration by promoting the regeneration of the native tissue.

Hip abductor tendon tears: where are we now?

Hip abductor tendon tear is a difficult problem to manage. The hip abductor mechanism is made up of the gluteus medius and minimus muscles, both of which contribute to stabilising the pelvis through the gait cycle. Tears of these tendons are likely due to iatrogenic injury during arthroplasty and chronic degenerative tendinopathy. Ultrasound and magnetic resonance imaging have provided limited clues regarding the pattern of disease and further work is required to clarify both the macro and microscopic pattern of disease. While surgery has been attempted over the last 2 decades, the outcomes are variable and the lack of high-quality studies have limited the uptake of surgical repair. Hip abductor tendon tears share many features with rotator cuff tears, hence, innovations in surgical techniques, materials and biologics may apply to both pathologies.

Application of a new polyester patch in arthroscopic massive rotator cuff repair-a prospective cohort study

BACKGROUND

Massive rotator cuff (RC) tears still present a clinically challenging problem, with reported rerupture rates in up to 94%. The study objective was to determine the impact of synthetic patch augmentation for massive RC tears.

METHODS

Between June 2012 and 2014, we performed 50 arthroscopic RC reconstructions augmented with a synthetic polyester patch. Pre- and postoperative imaging methods included arthrographic magnetic resonance imaging, arthrographic computed tomography, and ultrasound examination to determine tendon integrity or rerupture. Clinical outcome was evaluated using the Constant-Murley score and the subjective shoulder value. Mean clinical midterm and final follow-up was 22 months (9-35 months) and 52 months (25-74 months), respectively.

RESULTS

The mean Constant-Murley score increased significantly from 36.5 (±16.4 standard deviation [SD]) preoperatively to a midterm value of 81.2 (±9.6 SD; P < .0001) and further improved to a mean of 83.4 (±10.8 SD) at final follow-up. The mean subjective shoulder value increased from 40.3 (±24.3 SD) to 89.2 (±12.9 SD; P < .0001) at midterm and to 89.6 (±15.2 SD) at final follow-up. We observed 7 complete reruptures (14%). However, reruptures did not correlate with revision surgery, which was performed in 8 patients. The main reason for revision was frozen shoulder or arthrofibrosis with an intact reconstruction and patch, which was performed in 6 cases.

CONCLUSIONS

The retear rate of 14% compared favorably with nonaugmented RC repairs in the literature. Therefore, we conclude that patch augmentation in massive RC tears is feasible to reduce retears and to improve clinical outcome.

The clinical strategies for tendon repair with biomaterials: A review on rotator cuff and Achilles tendons

Tendon repair is a complex process due to the low tenocyte density, metabolism, and vascularization. Tears of rotator cuff (RCT) and Achilles tendons ruptures have a major impact on healthcare costs and quality of life of patients. Scaffolds are used to improve the healing rate after surgery and long-term results. A systematic search was carried out to identify the different types of scaffolds used during RCT and Achilles tendon repair surgery in the last 10 years. A higher number of clinical studies were reported on RCT ruptures. Biological scaffolds were used more than synthetic ones, for both rotator cuff and Achilles tendons. Moreover, platelet-rich plasma (PRP)-based scaffolds were the most widely used in RCT. A different type of synthetic scaffold was used in each of the five studies found. Biological scaffolds either provide variable results, in particular PRP-based ones, or poor results, such as bovine equine pericardium. All the synthetic scaffolds demonstrated a significant increase in clinical and functional scores in biomechanics, and a significant decrease in pain and re-tear rate in comparison to conventional surgery. Despite the limited number of studies, further investigation in the clinical use of synthetic scaffolds should be carried out.

A New Human-Derived Acellular Dermal Matrix for 1-Stage Coverage of Exposed Tendons in the Foot

The closure of wounds associated with soft tissue defects is surgically challenging, frequently requiring extensive plastic surgery and free flaps. The combination of ADM and STSG is an innovative method used to cover such wounds. The human-derived ADMs (H-ADMs) are the most described in the literature but according to European legislations, Companies H-ADMs outside the EC are not allowed to commercialize them in Europe, H-ADMs being “human products” and not “medical devices”, so being ruled by European legislations on transplants. The Skin Bank of the Bufalini Hospital (Cesena, Italy) obtained in 2009 the approval for the production and distribution of the first human cadaver-donor derived ADM from the Italian National Transplant Center and National Health Institute, we called with the Italian acronym M.O.D.A. (Matrice Omologa Dermica Acellulata). We present here the first use of a new H-ADM for treatment of distal lower extremity wounds with exposed tendons managed in one-stage pocedure with STSG. The excellent performance suggests that in cases where autologous tissue is unavailable or undesirable, the use of M.O.D.A. in one-stage procedure represents a promising alternative for covering wounds associated with tendons exposition.

Augmentation with a reinforced acellular fascia lata strip graft limits cyclic gapping of supraspinatus repairs in a human cadaveric model

BACKGROUND

A reinforced biologic strip graft was designed to mechanically augment the repair of rotator cuff tears that are fully reparable by arthroscopic techniques yet have a likelihood of failure. This study assessed the extent to which augmentation of human supraspinatus repairs with a reinforced fascia strip can reduce gap formation during in vitro cyclic loading.

METHODS

The supraspinatus tendon was sharply released from the proximal humerus and repaired back to its insertion with anchors in 9 matched pairs of human cadaveric shoulders. One repair from each pair was also augmented with a reinforced fascia strip. All repairs were subjected to cyclic mechanical loading of 5 to 180 N for 1000 cycles.

RESULTS

All augmented and nonaugmented repair constructs completed 1000 cycles of loading. Augmentation with a reinforced fascia strip graft significantly decreased the amount of gap formation compared with nonaugmented repairs. The average gap formation of augmented repairs was 1.5 ± 0.7 mm after the first cycle vs. 3.0 ± 1.2 mm for nonaugmented repairs (P = .003) and 5.0 ± 1.5 mm after 1000 cycles of loading, which averaged 24% ± 21% less than the gap formation of nonaugmented repairs (7.0 ± 2.8 mm, P = .014).

CONCLUSION

Cadaveric human supraspinatus repairs augmented with a reinforced fascia strip have significantly less initial stroke elongation and gap formation than repairs without augmentation. Augmentation limited gap formation to the greatest extent early in the testing protocol. Human studies are necessary to confirm the appropriate indications and effectiveness of augmentation scaffolds for rotator cuff repair healing in the clinical setting.

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.

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.

A New Human-Derived Acellular Dermal Matrix for Breast Reconstruction Available for the European Market: Preliminary Results

INTRODUCTION

The introduction of acellular dermal matrices (ADMs) contributed to the growing diffusion of direct-to-implant breast reconstruction (DTI-BR) following mastectomy for breast cancer. According to specific legislations, European specialists could not benefit from the use of human-derived ADMs, even though most evidence in the literature are available for this kind of device, showed optimal outcomes in breast reconstruction. The Skin Bank of the Bufalini Hospital (Cesena, Italy) obtained in 2009 the approval for the production and distribution of a new human cadaver-donor-derived ADM (named with the Italian acronym, MODA, for matrice omologa dermica acellulata) from the Italian National Transplant Center and National Health Institute. We report preliminary results of MODA application in direct-to-implant breast reconstruction following nipple-areola complex (NAC)-sparing mastectomy for breast cancer treatment.

MATERIALS AND METHODS

We prospectively enrolled all women undergoing NAC-sparing mastectomy for breast cancer and DTI-BR in our breast surgical unit from June 2015 to January 2017. We enrolled a selected population without previous chest wall irradiation, not being heavy tobacco smokers or diabetic, with a BMI < 30 kg/m² and requiring less than 550 cc silicone implants. We assessed short-term outcomes, defined as postoperative complications presenting in the first 30 postoperative days and long-term outcomes at 6 and 12 months.

RESULTS

From June 2015 to January 2017, we treated 56 breasts. At a mean follow-up of 14 months, we observed only two minor complications described as limited wound dehiscences, conservatively managed with complete resolution without implant exposure or re-intervention.

CONCLUSIONS

Our preliminary results show very good performance of MODA in direct-to-implant breast reconstruction following NAC-sparing mastectomy for breast cancer treatment. This is particularly relevant for the European market, where no other human-derived devices are available for breast reconstruction due to regulatory restrictions.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Extracellular matrix scaffolds for treatment of large volume muscle injuries: A review

OBJECTIVE

Large muscular or musculotendinous defects present a dilemma because of the inadequacies of current treatment strategies. Extracellular matrices (ECM) are potential clinically applicable regenerative biomaterials. This review summarizes information from the preclinical literature evaluating the use of ECM for muscle regeneration in animal models of volumetric muscle loss (VML).

STUDY DESIGN

Literature review.

SAMPLE POPULATION

Animal models of VML in which surgical repair was performed with an ECM product, with or without added cell populations.

METHODS

PubMed, Google Scholar, CAB abstracts, and Scopus were searched for preclinical studies using ECM in animal models of VML. The search terms "extracellular matrix," "VML," "muscle regeneration," "cell seeded," and "scaffold" identified 40 articles that met inclusion criteria of an animal model of VML in which surgical repair was performed with an ECM product, with or without added cell populations. Key skeletal muscle repair mechanisms and experimental findings on scaffold type, VML location, and experimental animal species were summarized.

CONCLUSIONS

Satellite cells and basal lamina are key endogenous contributors to skeletal muscle regeneration. ECM as a dynamic tissue component may provide structural integrity, signaling molecules, and a 3-dimensional topography conducive to muscle regeneration. Preclinical models of muscle repair most commonly used mice and rats (88%). Most experimental lesions were created in abdominal wall (33%), anterior tibialis (33%), latissimus dorsi (10%), or quadriceps (10%) muscles. Matrices varied markedly in source and preparation. Experimental outcomes of ECM and cell-seeded ECM implantation for muscle regeneration in VML were highly variable and dependent on matrix tissue source, preparation method, and anatomic site of injury. Scar tissue formation likely contributes to load transfer. Nonappendicular lesions had better regenerative results compared with appendicular VML.

CLINICAL SIGNIFICANCE

The preponderance of current evidence supports the use of ECM for muscle defect repair only in specific instances, such as nonappendicular and/or partial-thickness defects. Consequently, clinical use of ECM in veterinary patients requires careful consideration of the specific ECM product, lesion size and location, and loading circumstances.

The development of a decellularized extracellular matrix-based biomaterial scaffold derived from human foreskin for the purpose of foreskin reconstruction in circumcised males

The circumcision of males is emphatically linked to numerous sexual dysfunctions. Many of the purported benefits do not hold up to the scrutiny of extensive literature surveys. Involuntary circumcision, particularly when not medically warranted, is also associated with many psychological and emotional traumas. Current methods to reconstruct the ablated tissue have significant drawbacks and produce a simple substitute that merely imitates the natural foreskin. Extracellular matrix-based scaffolds have been shown to be highly effective in the repair and regeneration of soft tissues; however, due to the unique nature of the foreskin tissue, commercially available biomaterial scaffolds would yield poor results. Therefore, this study discusses the development and evaluation of a tissue engineering scaffold derived from decellularized human foreskin extracellular matrix for foreskin reconstruction. A chemicophysical decellularization method was applied to human foreskin samples, sourced from consenting adult donors. The resulting foreskin dermal matrices were analyzed for their suitability for tissue engineering purposes, by biological, histological, and mechanical assessment; fresh frozen foreskin was used as a negative control. Sterility of samples at all stages was ensured by microbiological analysis. MTT assay was used to evaluate the absence of viable cells, and histological analysis was used to confirm the maintenance of the extracellular matrix structure and presence/integrity of collagen fibers. Bioactivity was determined by submitting tissue extracts to enzyme-linked immunosorbent assay and quantifying basic fibroblast growth factor content. Mechanical properties of the samples were determined using tensile stress tests. Results found foreskin dermal matrices were devoid of viable cells (p < 0.0001) and the matrix of foreskin dermal matrices was maintained. Basic fibroblast growth factor content doubled within after decellularization (p < 0.0001). Tensile stress tests found no statistically significant differences in the mechanical properties (p < 0.05). These results indicate that the derived foreskin dermal matrix may be suitable in a regenerative approach in the reconstruction of the human foreskin.

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.

Graft Utilization in the Augmentation of Large-to-Massive Rotator Cuff Repairs: A Systematic Review

BACKGROUND

Current treatment options for symptomatic large-to-massive rotator cuff tears can reduce pain, but failure rates remain high. Surgeons have incorporated synthetic and biologic grafts to augment these repairs, with promising results. Multiple reviews exist that summarize these products; however, no systematic review has investigated the grafts' ability to maintain structural integrity after augmentation of large-to-massive rotator cuff repairs.

PURPOSE

To systematically review and evaluate the effectiveness of grafts in the augmentation of large-to-massive rotator cuff repairs.

STUDY DESIGN

Systematic review.

METHODS

A comprehensive search of 4 reputable databases was completed. Inclusion criteria were (1) large-to-massive rotator cuff tear, (2) graft augmentation of primary repairs ± primary repair control group, and (3) minimum clinical and radiologic follow-up of 12 months. Two reviewers screened the titles, abstracts, and full articles and extracted the data from eligible studies. Results were summarized into evidence tables stratified by graft origin and level of evidence.

RESULTS

Ten studies fit the inclusion criteria. Allograft augmentation was functionally and structurally superior to primary repair controls, with intact repairs in 85% versus 40% of patients (P < .01). This was supported by observational study data. Xenograft augmentation failed to demonstrate superiority to primary repair controls, with worse structural healing rates (27% vs 60%; P =.11). Both comparative studies supported this finding. There have also been many reports of inflammatory reactions with xenograft use. Polypropylene patches are associated with improved structural (83% vs 59% and 49%; P < .01) and functional outcomes when compared with controls and xenograft augmentation; however, randomized data are lacking.

CONCLUSION

Augmentation of large-to-massive rotator cuff repairs with human dermal allografts is associated with superior functional and structural outcome when compared with conventional primary repair. Xenograft augmentation failed to demonstrate a statistically significant difference and may be associated with worse rerupture rates and occasional severe inflammatory reactions. Polypropylene patches have initial promising results. Research in this field is limited; future researchers should continue to develop prospective, randomized controlled trials to establish clear recommendations.

Extracellular Matrix of Current Biological Scaffolds Promotes the Differentiation Potential of Mesenchymal Stem Cells

PURPOSE

The purpose of this study was to quantitatively assess the ability of bone marrow-derived mesenchymal stem cells (bMSC) to differentiate toward bone, fat, cartilage, and tendon lineages when grown on commercially available scaffolds compared with control and native tendon tissue.

METHODS

BMSCs were cultured and analyzed by fluorescent automated cells sorting for surface markers CD73, -90, and -105. BMSCs were grown on rotator cuff tendon (RCT), decellularized human dermis patch (DDP), bilayer collagen matrix, and fibrin matrix (FM) to test their differentiation potential using quantitative polymerase chain reaction and establish markers for osteogenic, adipogenic, chondrogenic, and tenogenic lineages. Immunocytochemical testing was used to determine the specific proteins present on the scaffolds.

RESULTS

Alkaline phosphatase and osteocalcin gene expression was significantly higher on RCT (P < .001) and collagen scaffold (CS) (P < .001) compared with DDP and FM scaffolds (P < .001, P < .001). When differentiated toward a cartilage lineage, bMSCs grown on CS had significantly more type II collagen and aggrecan compared with DDP (P < .001, P < .001), FM (P < .001, P < .001), and RCT (P < .001, P < .001). Differentiated bMSCs grown on the CS had a significant increase in PPARγ and FABP4 gene expression compared with bMSCs grown on all other scaffolds (all P < .001). The differentiation of bMSCs into tendon on CSs had significantly more tenacin C, decorin, and type III collagen gene expression when compared with RCT, DDP, and FM (all P < .001). Decorin gene expression in the control undifferentiated CS was also significantly increased, suggesting that the matrix alone may promote a tenogenic lineage (P = .637).

CONCLUSIONS

Differences in the extracellular matrix composition of scaffolds significantly impact their potential to promote differentiation of bMSCs. Comparing the native RCT to the tested scaffolds showed that a high content of type I and III collagen significantly increased the potential of bMSCs to differentiate toward bone, tendon, fat, and cartilage lineages.

CLINICAL RELEVANCE

This in vitro study shows the differences between commercially available scaffolds for rotator cuff repairs. Therefore, these results support clinical use depending on the surgical intention and the potential of bMSCs to differentiate into bone, tendon, cartilage, and fat tissue.

Outcomes After Patch Use in Rotator Cuff Repair

PURPOSE

To provide a comprehensive review of clinical outcomes and retear rates after patch use in rotator cuff repair, and to determine the differences between available graft types and techniques.

METHODS

A systematic review was conducted from database (PubMed, Medline, Scopus, Embase) inception to January 2015 for English-language articles reporting outcome data with 9 months' minimum follow-up. Studies were assessed by 2 reviewers who collected pertinent data, with outcomes combined to generate frequency-weighted means.

RESULTS

Twenty-four studies met the inclusion criteria. The frequency-weighted mean age was 61.9 years with 35.4 months' follow-up. The mean improvements in postoperative range of motion in the forward elevation, abduction, external rotation, and internal rotation planes were 58.6°, 66.2°, 16.6°, and 16.1°, respectively, and postoperative abduction strength improved by 3.84 kg. American Shoulder and Elbow Surgeons, University of California-Los Angeles, Constant, Penn, and Oxford scores improved by 39.3, 10.7, 40.8, 34.4, and 17.6, respectively. Augmentation and interposition techniques showed similar improvements in range of motion, strength, and patient-reported outcomes (PROs), whereas xenografts showed less improvement in PROs compared with other graft types. Studies reported improvements in pain and activities of daily living (ADLs), with greater than 90% overall satisfaction, although few patients (13%) were able to return to preinjury activity. Whereas interposition and augmentation techniques showed similar improvements in pain and ADLs, xenografts showed less improvement in ADLs than other graft types. The overall retear rate was 25%, with rates of 34% and 12% for augmentation and interposition, respectively, and rates of 44%, 23%, and 15% for xenografts, allografts, and synthetic grafts, respectively.

CONCLUSIONS

We report improvements in clinical and functional outcomes, with similar results for augmentation and interposition techniques, whereas xenografts showed less improvement than synthetic grafts and allografts in PROs and ADLs. Retear rates may be lower with the interposition technique or in patients with synthetic grafts or allografts.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Mechanical risk of rotator cuff repair failure during passive movements: A simulation-based study

BACKGROUND

Despite improvements in rotator cuff surgery techniques, re-tear rate remains above 20% and increases with tear severity. Mechanical stresses to failure of repaired tendons have been reported. While optimal immobilization postures were proposed to minimize this stress, post-operative rehabilitation protocols have never been assessed with respect to these values. Purpose was to use musculoskeletal simulation to predict when the stress in repaired tendons exceeds safety limits during passive movements. Hence, guidelines could be provided towards safer post-operative exercises.

METHODS

Sixteen healthy participants volunteered in passive three-dimensional shoulder range-of-motion and passive rehabilitation exercises assessment. Stress in all rotator cuff tendons was predicted during each movement by means of a musculoskeletal model using simulations with different type and size of tears. Safety stress thresholds were defined based on repaired tendon loads to failure reported in the literature and used to discriminate safe from unsafe ranges-of-motion.

FINDINGS

Increased tear size and multiple tendons tear decreased safe range-of-motion. Mostly, glenohumeral elevations below 38°, above 65°, or performed with the arm held in internal rotation cause excessive stresses in most types and sizes of injury during abduction, scaption or flexion. Larger safe amplitudes of elevation are found in scapular plane for supraspinatus alone, supraspinatus plus infraspinatus, and supraspinatus plus subscapularis tears.

INTERPRETATION

This study reinforces that passive early rehabilitation exercises could contribute to re-tear due to excessive stresses. Recommendations arising from this study, for instance to keep the arm externally rotated during elevation in case of supraspinatus or supraspinatus plus infraspinatus tear, could help prevent re-tear.

Recent Scientific Advances Towards the Development of Tendon Healing Strategies

There exists a range of surgical and non-surgical approaches to the treatment of both acute and chronic tendon injuries. Despite surgical advances in the management of acute tears and increasing treatment options for tendinopathies, strategies frequently are unsuccessful, due to impaired mechanical properties of the treated tendon and/or a deficiency in progenitor cell activities. Hence, there is an urgent need for effective therapeutic strategies to augment intrinsic and/or surgical repair. Such approaches can benefit both tendinopathies and tendon tears which, due to their severity, appear to be irreversible or irreparable. Biologic therapies include the utilization of scaffolds as well as gene, growth factor, and cell delivery. These treatment modalities aim to provide mechanical durability or augment the biologic healing potential of the repaired tissue. Here, we review the emerging concepts and scientific evidence which provide a rationale for tissue engineering and regeneration strategies as well as discuss the clinical translation of recent innovations.

Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Preoperative Factors Associated With Outcome Deterioration Over 2 Years

BACKGROUND

Arthroscopic partial repair is a treatment option in irreparable large-to-massive rotator cuff tears without arthritic changes. However, there are indications that arthroscopic partial repair does not yield satisfactory outcomes.

PURPOSE

To report the clinical and radiographic results of arthroscopic partial repairs in patients with irreparable large-to-massive cuff tears. In addition, an analysis was performed regarding preoperative factors that may influence patient outcomes and patient-rated satisfaction over time.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From 2005 to 2011, a total of 31 patients who underwent arthroscopic partial repair for irreparable large-to-massive cuff tears were retrospectively evaluated. Partial repair was defined as posterior cuff tissue repair with or without subscapularis tendon repair to restore the transverse force couple of the cuff. Pain visual analog scale (PVAS), questionnaire results (American Shoulder and Elbow Surgeons [ASES] and Simple Shoulder Test [SST]), and radiographic changes (acromiohumeral distance and degenerative change) were assessed preoperatively, at first follow-up (roughly 1 year postoperatively), and at final follow-up (>2 years postoperatively). Patients rated their satisfaction level at each postoperative follow-up as well. Preoperative factors that might influence outcomes, such as patient demographics, tear size, and fatty infiltration, were investigated.

RESULTS

The preoperative, first follow-up, and final follow-up results for mean PVAS (5.13, 2.13, and 3.16, respectively) and questionnaires (ASES: 41.97, 76.37, and 73.78; SST: 3.61, 6.33, and 6.07, respectively) improved significantly (all P < .05). Radiographic evaluation showed no difference compared with preoperative status. Nevertheless, patient-rated satisfaction at final evaluation was inferior: 16 good responses ("very satisfied" and "satisfied") and 15 poor responses ("rather the same" and "dissatisfied"). Despite initial improvements in both groups (P < .05), patients with poor satisfaction demonstrated statistically significant deterioration in mean PVAS (from 2.07 to 4.67), questionnaire scores (ASES: from 74.56 to 59.80; SST: from 5.11 to 3.81), and acromiohumeral distance (from 7.19 to 5.06 mm) between the first and final follow-up (all P < .05). Patients with good satisfaction showed no significant difference or they improved (P > .05) from the first to the final follow-up. Among preoperative factors, fatty infiltration of the teres minor was identified as the only statistically significant factor affecting patient-rated satisfaction (P = .007).

CONCLUSION

This study showed that arthroscopic partial repair may produce initial improvement in selected outcomes at 2-year follow-up. However, about half of the patients in the study were not satisfied with their outcomes, which had deteriorated over time. Preoperative fatty infiltration of the teres minor was the only factor that correlated with worse final outcomes and poor satisfaction after arthroscopic partial repair.

Clinical outcomes in patients undergoing revision rotator cuff repair with extracellular matrix augmentation

Outcomes following revision surgery for failed rotator cuff repairs are far less predictable than and are associated with decreased patient satisfaction compared with primary repairs. Extracellular matrix augmentation (ECM) may improve the biologic potential for healing during revision repair. The authors examined clinical outcomes and healing rates based on postoperative imaging of patients who underwent revision open rotator cuff repair with an ECM patch for symptomatic recurrent rotator cuff tear. Twenty-four (77%) of 31 patients with a mean follow-up of 50 months (range, 30-112 months) completed post-revision surgery outcome questionnaires at a mean of 5.3 years after revision surgery, and 16 patients (67%) underwent a physical examination and repeat imaging (ultrasound or magnetic resonance imaging) at a mean of 4.2 years after revision surgery. Ten (63%) of those 16 patients were found to have failed revision rotator cuff repair on imaging, with American Shoulder and Elbow Surgeons (ASES) outcome measures that were significantly (P=.04) better in patients with confirmed intact repairs than those with confirmed failed revision repair. Outcome measures for all patients (n=24) included a mean ASES score of 67.2 (SD, 27.9) and a mean Single Assessment Numeric Evaluation (SANE) score of 66.9 (SD, 26.0). Based on these scores, excellent results were achieved in 24% of patients, good in 13%, fair in 21%, and poor in 42%. Results of this investigation demonstrated that augmentation of revision rotator cuff repair with an ECM patch through an open approach showed no significant improvement in outcomes when compared to historical reports without augmentation.

Biologics for tendon repair

Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management.

The benefit of synthetic versus biological patch augmentation in the repair of posterosuperior massive rotator cuff tears: a 3-year follow-up study

BACKGROUND

Rotator cuff repair typically results in a satisfactory, although variable, clinical outcome. However, anatomic failure of the repaired tendon often occurs.

HYPOTHESIS

Patch augmentation can improve the results of open rotator cuff repair by supporting the healing process, protecting the suture, and reducing friction in the subacromial space.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 152 patients with a posterosuperior massive rotator cuff tear were treated by open repair only (control group; n = 51; mean age, 67.06 ± 4.42 years), open repair together with collagen patch augmentation (collagen group; n = 49; mean age, 66.53 ± 5.17 years), or open repair together with polypropylene patch augmentation (polypropylene group; n = 52; mean age, 66.17 ± 5.44 years) and were retrospectively studied. Patients were evaluated preoperatively and after 36 months with a visual analog scale (VAS) and the University of California, Los Angeles (UCLA) shoulder rating scale and by measuring elevation of the scapular plane and strength with a dynamometer. The VAS and UCLA scores were also obtained 2 months postoperatively. Tendon integrity was assessed after 1 year by ultrasound. Patients were homogeneous as per the preoperative assessment.

RESULTS

After 2 months, results (mean ± standard deviation) for the control, collagen, and polypropylene groups, respectively, were as follows: VAS scores were 6.96 ± 1.11, 6.46 ± 1.02, and 4.92 ± 0.90, while UCLA scores were 11.29 ± 1.46, 11.40 ± 1.51, and 19.15 ± 1.99. After 36 months, the mean scores for the respective groups were 3.66 ± 1.05, 4.06 ± 1.02, and 3.28 ± 1.10 for the VAS and 14.88 ± 1.98, 14.69 ± 1.99, and 24.61 ± 3.22 for the UCLA scale. In addition, after 36 months, elevation on the scapular plane was 140.68° ± 9.84°, 140.61° ± 12.48°, and 174.71° ± 8.18°, and abduction strength was 8.73 ± 0.54 kg, 9.03 ± 0.60 kg, and 13.79 ± 0.64 kg for the control, collagen, and polypropylene groups, respectively. The retear rate after 12 months was 41% (21/51) for the control group, 51% (25/49) for the collagen group, and 17% (9/52) for the polypropylene group. In particular, the reduced 12-month retear rate and the increased UCLA scores, abduction strength, and elevation at 3-year follow-up were statistically significant for patients treated with a polypropylene patch compared with those treated with repair only or with a collagen patch.

CONCLUSION

Polypropylene patch augmentation of rotator cuff repair was demonstrated to significantly improve the 36-month outcome in terms of function, strength, and retear rate.

Properties of biologic scaffolds and their response to mesenchymal stem cells

PURPOSE

The purpose of this study was to examine, in vitro, the cellular response of human mesenchymal stem cells (MSCs) to sample types of commercially available scaffolds in comparison with control, native tendon tissue (fresh-frozen rotator cuff tendon allograft).

METHODS

MSCs were defined by (1) colony-forming potential; (2) ability to differentiate into tendon, cartilage, bone, and fat tissue; and (3) fluorescence-activated cell sorting analysis (CD73, CD90, CD45). Samples were taken from fresh-frozen human rotator cuff tendon (allograft), human highly cross-linked collagen membrane (Arthroflex; LifeNet Health, Virginia Beach, VA), porcine non-cross-linked collagen membrane (Mucograft; Geistlich Pharma, Lucerne, Switzerland), a human platelet-rich fibrin matrix (PRF-M), and a fibrin matrix based on platelet-rich plasma (ViscoGel; Arthrex, Naples, FL). Cells were counted for adhesion (24 hours), thymidine assay for cell proliferation (96 hours), and live/dead stain for viability (168 hours). Histologic analysis was performed after 21 days, and the unloaded scaffolds were scanned with electron microscopy.

RESULTS

MSCs were successfully differentiated into all cell lines. A significantly greater number of cells adhered to both the non-cross-linked porcine collagen scaffold and PRF-M. Cell activity (proliferation) was significantly higher in the non-cross-linked porcine collagen scaffold compared with PRF-M and fibrin matrix based on platelet-rich plasma. There were no significant differences found in the results of the live/dead assay.

CONCLUSIONS

Significant differences in the response of human MSCs to biologic scaffolds existed. MSC adhesion, proliferation, and scaffold morphology evaluated by histologic analysis and electron microscopy varied throughout the evaluated types of scaffolds. Non-cross-linked porcine collagen scaffolds showed superior results for cell adhesion and proliferation, as well as on histologic evaluation.

CLINICAL RELEVANCE

This study enables the clinician and scientist to choose scaffold materials according to their specific interaction with MSCs.

Open repair of isolated traumatic subscapularis tendon tears with a synthetic soft tissue reinforcement

BACKGROUND

Missed or chronic subscapularis tendon ruptures may have muscle atrophy and tendon retraction resulting in a large defect with high risk of re-tear after a surgical repair. To improve the clinical results of this challenging surgery, the repaired tendon could be augmented with endogenous or exogenous materials. The purpose of this study was to evaluate the structural tendon integrity and clinical outcomes after an open subscapularis tendon repair with a synthetic soft tissue reinforcement.

MATERIALS AND METHODS

Ten patients were managed with an open repair of the subscapularis tendon with augmentation by means of SportMesh, a readily available synthetic degradable poly(urethaneurea) scaffold. Clinical findings were assessed for all patients preoperatively and postoperatively with use of the visual analog scale for pain and the DASH scoring system. All patients had an ultrasonographic study at the latest follow-up.

RESULTS

The visual analog scale for pain (mean ± standard deviation) improved significantly (P < 0.01) from 7.9 ± 1.1 preoperatively to 1.95 ± 1.85 at the latest clinical follow-up evaluation. The mean DASH score at the latest clinical follow-up was 12.63 %. Ultrasound imaging revealed a structural intact repair at follow-up in 9 shoulders (90 %) with average 5.4 mm in thickness (4.3 mm in the contralateral healthy side).

CONCLUSIONS

At a median follow-up of 23 months, 80 % (8 of 10) of patients had a good or excellent result after an open subscapularis tendon repair with a soft tissue reinforcement. As a synthetic material, SportMesh Soft Tissue Reinforcement eliminates the risk of collagen reactions, which may result from collagen or dermis patches. Although the follow-up is relatively short, our series shows a promising durable repair with a 10 % re-tear rate at an average of 23 postoperative months. Level of evidence Case Series, Treatment Study, Level IV.

Response of human chondrocytes and mesenchymal stromal cells to a decellularized human dermis

Background

Although progress has been made in the treatment of articular cartilage lesions, they are still a major challenge because current techniques do not provide satisfactory long-term outcomes. Tissue engineering and the use of functional biomaterials might be an alternative regenerative strategy and fulfill clinical needs. Decellularized extracellular matrices have generated interest as functional biologic scaffolds, but there are few studies on cartilage regeneration. The aim of this study was to evaluate in vitro the biological influence of a newly developed decellularized human dermal extracellular matrix on two human primary cultures.

Methods

Normal human articular chondrocytes (NHAC-kn) and human mesenchymal stromal cells (hMSC) from healthy donors were seeded in polystyrene wells as controls (CTR), and on decellularized human dermis batches (HDM_derm) for 7 and 14 days. Cellular proliferation and differentiation, and anabolic and catabolic synthetic activity were quantified at each experimental time. Histology and scanning electron microscopy were used to evaluate morphology and ultrastructure.

Results

Both cell cultures had a similar proliferation rate that increased significantly (p < 0.0005) at 14 days. In comparison with CTR, at 14 days NHAC-kn enhanced procollagen type II (CPII, p < 0.05) and aggrecan synthesis (p < 0.0005), whereas hMSC significantly enhanced aggrecan synthesis (p < 0.0005) and transforming growth factor-beta1 release (TGF-β1, p < 0.0005) at both experimental times. Neither inflammatory stimulus nor catabolic activity induction was observed. By comparing data of the two primary cells, NHAC-kn synthesized significantly more CPII than did hMSC at both experimental times (p < 0.005), whereas hMSC synthesized more aggrecan at 7 days (p < 0.005) and TGF-β1 at both experimental times than did NHAC-kn (p < 0.005).

Conclusions

The results obtained showed that in in vitro conditions HDM_derm behaves as a suitable scaffold for the growth of both well-differentiated chondrocytes and undifferentiated mesenchymal cells, thus ensuring a biocompatible and bioactive substrate. Further studies are mandatory to test the use of HDM_derm with tissue engineering to assess its therapeutic and functional effectiveness in cartilage regeneration.

Does augmentation with a reinforced fascia patch improve rotator cuff repair outcomes?

BACKGROUND

Scaffold devices are used to augment rotator cuff repairs in humans. While the strength of a novel poly-L-lactic acid-reinforced (human) fascia patch has been documented, it is unclear whether such patches will enhance the strength or likelihood of healing of rotator cuff repairs.

QUESTIONS/PURPOSES

In a canine shoulder model, we asked: Do tendon repairs augmented with a reinforced fascia patch have (1) increased biomechanical properties at Time 0 and (2) less tendon retraction and increased cross-sectional area and biomechanical properties after 12 weeks of healing compared to repairs without augmentation? (3) Do the biomechanical properties of tendon repairs reach normal values by 12 weeks of healing? And (4) is the host response associated with use of the reinforced fascia patch biocompatible?

METHODS

Eleven dogs underwent bilateral shoulder surgery with partial release and acute repair of the infraspinatus tendon, one shoulder with augmentation and one without augmentation. Repair retraction, cross-sectional area, biomechanical properties, and biocompatibility were assessed at 12 weeks.

RESULTS

At Time 0, the mean ± SD ultimate load of augmented repairs was 296 ± 130 N (46% ± 25%) more than nonaugmented repairs, with no difference in stiffness between groups. At 12 weeks, the ultimate load of augmented repairs averaged 192 ± 213 N (15% ± 16%) less than nonaugmented repairs, with no difference in stiffness between groups. At the tendon repair site at 12 weeks, the fascia patch showed a biocompatible host tissue response.

CONCLUSIONS

The biomechanical properties of repairs augmented with a reinforced fascia patch demonstrated greater ultimate load at Time 0 than nonaugmented repairs but remained essentially unchanged after 12 weeks of healing, despite improvements in the ultimate load of nonaugmented controls in the same time frame.

Scaffold devices for rotator cuff repair

Rotator cuff tears affect 40% or more of those aged older than 60 years, and repair failure rates of 20% to 70% remain a significant clinical challenge. Hence, there is a need for repair strategies that can augment the repair by mechanically reinforcing it, while at the same time biologically enhancing the intrinsic healing potential of the tendon. Tissue engineering strategies to improve rotator cuff repair healing include the use of scaffolds, growth factors, and cell seeding, or a combination of these approaches. Currently, scaffolds derived from mammalian extracellular matrix, synthetic polymers, and a combination thereof, have been cleared by the U.S. Food and Drug Administration and are marketed as medical devices for rotator cuff repair in humans. Despite the growing clinical use of scaffold devices for rotator cuff repair, there are numerous questions related to their indication, surgical application, safety, mechanism of action, and efficacy that remain to be clarified or addressed. This article reviews the current basic science and clinical understanding of commercially available synthetic and extracellular matrix scaffolds for rotator cuff repair. Our review will emphasize the host response and scaffold remodeling, mechanical and suture-retention properties, and preclinical and clinical studies on the use of these scaffolds for rotator cuff repair. We will discuss the implications of these data on the future directions for use of these scaffolds in tendon repair procedures.