Retears and complication rates after arthroscopic rotator cuff repair with scaffolds: a systematic review

Superior capsular reconstruction with the long head of the biceps tendon achieves excellent clinical results and low rotator cuff rerupture rates one year after cuff repair surgery

PURPOSE

To analyze the clinical one-year evolution of healed and rerupture lesions in patients who received a rotator cuff repair plus Superior Capsular Reconstruction (SCR) with the long head of the biceps (LHB). Moreover, to compare this evolution between men and women.

METHODS

A pilot study was conducted on patients who underwent a rotator cuff repair plus SCR with LHB between February 2021 and June 2022. All patients completed pre-operative and one-year post-operative evaluations for tendon type of tear and tendon integrity using Magnetic Resonance Imaging (MRI)after one year of the surgery. Besides, functionality was evaluated with the American Shoulder and Elbow Surgeons (ASES) score; the visual analog scale for pain (VAS); and the Constant score.

RESULTS

A total of 38 patients completed the one-year final evaluation, they presented an increased functionality score to 83 and 86 in Constant and ASES scales (p < .001), respectively. Besides, 84% of the patients presented a healed cuff, while rerupture occurred in 16% of the patients. There were differences between the healed and rerupture patients in the total Constant score, with a remarkable increase in the strength subscale, almost double for patients with healed cuff (p < .001); in the same way, daily life activity score, and balance subscale increased, while pain score decreased in the healed cuff group (p < .05). There was no difference in functionality between men and women (p > .05). Besides, almost all patients achieved the MCID in both ASES and Constant total scores, irrespectively of the healing group.

CONCLUSION

The cuff repair using SCR with the LHB achieved a low percentage of rerupture and a functional improvement after one year of follow-up. Patients who healed the lesion presented more strength and better performance in daily life activities than those with cuff repurture. Thus, SCR + LHB procedure can be considered an efficient technique for rotator cuff repair surgery for both men and women. Although a comparison with a control group is needed to confirm these findings.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Translational Research on Orthobiologics in the Treatment of Rotator Cuff Disease: From the Laboratory to the Operating Room

Rotator cuff disease is one of the most common human tendinopathies and can lead to significant shoulder dysfunction. Despite efforts to improve symptoms in patients with rotator cuff tears and healing rates after rotator cuff repair, high rates of failed healing and persistent shoulder morbidity exist. Increasing interest has been placed on the utilization of orthobiologics-scaffolds, cell-based augmentation, platelet right plasma (platelet-rich plasma), and small molecule-based strategies-in the management of rotator cuff disease and the augmentation of rotator cuff repairs. This is a complex topic that involves novel treatment strategies, including patches/scaffolds, small molecule-based, cellular-based, and tissue-derived augmentation techniques. Ultimately, translational research, with a particular focus on preclinical models, has allowed us to gain some insights into the utility of orthobiologics in the treatment of rotator cuff disease and will continue to be critical to our further understanding of the underlying cellular mechanisms moving forward.

Potential of Aligned Electrospun PLGA/SIS Blended Nanofibrous Membrane for Tendon Tissue Engineering

Tendons are responsible for transmitting mechanical forces from muscles to bones for body locomotion and joint stability. However, tendons are frequently damaged with high mechanical forces. Various methods have been utilized for repairing damaged tendons, including sutures, soft tissue anchors, and biological grafts. However, tendons experience a higher rate of retear post-surgery due to their low cellularity and vascularity. Surgically sutured tendons are vulnerable to reinjury due to their inferior functionality when compared with native tendons. Surgical treatment using biological grafts also has complications such as joint stiffness, re-rupture, and donor-site morbidity. Therefore, current research is focused on developing novel materials that can facilitate the regeneration of tendons with histological and mechanical characteristics similar to those of intact tendons. With respect to the complications in association with the surgical treatment of tendon injuries, electrospinning may be an alternative for tendon tissue engineering. Electrospinning is an effective method for fabrication of polymeric fibers with diameters ranging from nanometers to micrometers. Thus, this method produces nanofibrous membranes with an extremely high surface area-to-volume ratio, which is similar to the extracellular matrix structure, making them suitable candidates for application in tissue engineering. Moreover, it is possible to fabricate nanofibers with specific orientations that are similar to those of the native tendon tissue using an adequate collector. To increase the hydrophilicity of the electrospun nanofibers, natural polymers in addition to synthetic polymers are used concurrently. Therefore, in this study, aligned nanofibers composed of poly-d,l-lactide-co-glycolide (PLGA) and small intestine submucosa (SIS) were fabricated using electrospinning with rotating mandrel. The diameter of aligned PLGA/SIS nanofibers was 568.44 ± 135.594 nm, which closely resembles that of native collagen fibrils. Compared to the results of the control group, the mechanical strength exhibited by the aligned nanofibers was anisotropic in terms of break strain, ultimate tensile strength, and elastic modulus. Elongated cellular behavior was observed in the aligned PLGA/SIS nanofibers using confocal laser scanning microscopy, indicating that the aligned nanofibers were highly effective with regard to tendon tissue engineering. In conclusion, considering its mechanical properties and cellular behavior, aligned PLGA/SIS is a promising candidate for tendon tissue engineering.

Dermal Allograft Augmentation for Rotator Cuff Tears

Large and massive rotator cuff tears continue to be challenging for shoulder surgeons. Given the high percentage of retears after repair of these tears, several surgical technical advancements have been proposed. The use of grafts (xenograft, synthetic, and allograft) as an augmentation of the repair has been growing over the last several years in an attempt to improve structural integrity and postoperative outcomes. Patch augmentation with dermal allografts is the most commonly used, showing promising biomechanical, structural, and functional outcomes. Several factors have been associated with healing outcomes, including age, tear size, and fatty degeneration. The rotator cuff healing index can be used to assess for patients with Hamada grades 1 and 2 with elevated retear risk and potential indications for repair with graft augmentation. A score of 7 points represents a reasonable threshold for the addition of a dermal allograft due to a significant reduction in healing rates when comparing patients with a score of 6 points (66%) to 7 points (only 38%) without augmentation of the repair. Biomechanical studies have demonstrated a greater maximum failure load compared with standard repair. The healing rates of rotator cuff repairs using scaffolds range between 60% and 85%, compared with 40% with nonaugmented repairs. Moreover, the use of repair augmentation has been associated with improved range of motion and functional scores compared with nonaugmented repairs, with allografts showing the best visual analog scale pain score and postoperative external rotation results. Given these favorable healing rates, functional outcomes, and low complication rates, augmenting rotator cuff repairs with a dermal allograft may be a suitable option in active patients with a diminished chance of postoperative healing.

Poor Results After Arthroscopic Treatment of Irreparable Rotator Cuff Tears Using a Subacromial Balloon Spacer

INTRODUCTION

Arthroscopic balloon spacer arthroplasty (BSA) is a relatively recent procedure for patients with irreparable rotator cuff tears, conceived to prevent degenerative joint changes and relieve subacromial pain.

METHODS

This is a retrospective case series of 16 consecutive patients treated with BSA and followed up for a minimum 12 months. Besides BSA, partial tendon repair was done whenever possible. Radiographical parameters such as acromiohumeral distance and Hamada stage were measured preoperatively and postoperatively. Range of motion, functional results (Constant score; Simple Shoulder Test; American Shoulder and Elbow Surgeons score; and Disabilities of the Arm, Shoulder, and Hand score), health-related quality of life results with the EuroQol Five Dimensions tool, complications, and patient satisfaction were also analyzed.

RESULTS

The mean age was 64 ± 10.3 years, and the male/female ratio was 6/10. Partial repair was achieved in five patients (31.2%) and did not influence functional or health-related quality of life results ( P = 0.11). The mean acromiohumeral distance and Hamada stage worsened from preoperative measures (3.7 ± 2.0 mm and 2.3 ± 1.1) to final follow-up measures (3.1 ± 2.4 mm and 3.1 ± 1.3). Shoulder abduction increased by 7.8° ± 26.8° and forward flexion decreased by 25.5° ± 32.4° after surgery. The functional results at the final follow-up were Constant 49.5 ± 18.0; American Shoulder and Elbow Surgeons 60.2 ± 27.2; Simple Shoulder Test 8.5 ± 4.6; and Disabilities of the Arm, Shoulder, and Hand 32.7 ± 12.1. The mean index value for the EuroQol Five Dimensions was 0.79, and perceived quality of life was 85.6 ± 15.4 of 100 points. 62.5% of the patients (10) were satisfied with surgery. The complication rate was 13% (2), accounting for one deep infection and one balloon migration.

CONCLUSION

Theoretical benefits of BSA for delaying superior humeral head translation and arthropathic changes could not be demonstrated in our series. Its functional results and satisfaction rates are low, but self-reported quality of life after surgery does not seem impaired. Complications do not occur frequently but require reintervention and endanger joint viability.

LEVEL OF EVIDENCE

Level IV (case series).

Racial disparities in outcomes of arthroscopic rotator cuff repair: A propensity score matched analysis using multiple national data sets

BACKGROUND

Disparities in access, utilization and outcomes exist throughout the healthcare system for minority groups, including racial and ethnic minorities; these disparities have wide-reaching implications for individuals as well as the healthcare system as a whole. This study will examine the impact of race on short and medium term outcomes for patients undergoing rotator cuff repair (RCR) using matched cohorts.

METHODS

Patients undergoing arthroscopic rotator cuff repair from 2016 to 2018 were extracted from two national databases: the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) and TriNetX Research Network. Using the ACS-NSQIP database, univariate analysis was performed to identify differences in comorbidities between white and minority patients. Patients were propensity score matched based on significant differences between groups and 30-day postoperative outcomes were assessed. These comorbidities were then used to propensity score match white and minority patients in the TriNetX database and two-year postoperative outcomes were evaluated.

RESULTS

Following propensity score matching, 3716 patients remained in each group from the ACS-NSQIP database and 4185 patients remained in each group from the TriNetX database. The OR time for minority patients was longer than white patient in the ACS-NSQIP database (92.2 vs. 87.6 min, p < .001). There was no difference in medium-term outcomes for repeat RCR, infection or frozen shoulder between white and minority patients in the TriNetX database.

CONCLUSION

After propensity score matching the only significant short-term outcome between white and minority patients undergoing RCR was a difference in OR time; there were no differences in medium-term outcomes. This may indicate that the source of racial disparities is one of access to healthcare rather than an innate difference in the patients' outcomes. Further study is needed to elucidate this issue.

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.

Mesenchymal stem cell-derived exosomes: therapeutic implications for rotator cuff injury

Rotator cuff injuries are a common clinical condition of the shoulder joint. Surgery that involves reattaching the torn tendon to its humeral head bony attachment has a somewhat lower success rate. The scar tissue formed during healing of the rotator cuff leads to poor tendon-related mechanical properties. To promote healing, a range of genetic interventions, as well as cell transplantation, and many other techniques have been explored. In recent years, the therapeutic promise of mesenchymal stem cells (MSCs) has been well documented in animal and clinical studies. Some data have suggested that MSCs can promote angiogenesis, reduce inflammation and cell proliferation and increase collagen deposition. These functions are likely paracrine effects of MSCs, particularly mediated through exosomes. Here, we review the use of MSCs-related exosomes in tissues and organs. We also discuss their potential utility for treating rotator cuff injuries, and explore the underlying mechanisms of their effects.

The efficacy of platelet-rich plasma in arthroscopic rotator cuff repair: A protocol of randomized controlled trial

BACKGROUND

Platelet-rich plasma (PRP), an autologous platelet concentrate (contain a large number of growth factors), has been widely investigated in healing and rebuilding the bone and tendon tissue. The objective of this prospective randomized research is to study and then compare the long-term effectiveness of the repair of arthroscopic rotator cuff without and with the platelet-rich plasma. It is assumed that there is no difference in the clinical results between patients receiving the repair of arthroscopic rotator cuff and the patients who do not receive PRP enhancement.

METHODS

This current study is a prospective, single-center, controlled, and randomized experiment. This study was reviewed and permitted via the institutional review committee of our hospital. All the patients will receive the written informed consent in order to involve in our clinical experiment. Patients were selected from the patients who received the repair of arthroscopic rotator cuff. Patients who meet the following conditions will be included in this study: ages ranges from 18 to 55; patients with complete tear of rotator cuff confirmed during operation; the patients agreed to wear the abduction stent for 4 weeks after operation; the preoperative count of platelet count is >150,000. All patients were evaluated at follow-up and baseline for the scores of Constant-Murley (CM) and American Shoulder and Elbow Surgeons (ASES), the numerical rating scale (NRS), and retear rate. The analysis is implemented with the SPSS 16.0 (SPSS Inc., Chicago, IL), the significance level remain at P < .05.

CONCLUSIONS

The results of this study will provide useful new information on whether PRP is effective in the arthroscopic rotator cuff repair patients.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry6108).

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.

Electrospun PCL/Gel-aligned scaffolds enhance the biomechanical strength in tendon repair

Tendons can transmit mechanical force from muscles to bones for movement. However, the mechanical strength of tendons is compromised after surgery, thus causing a high rate of tendon retear. Hence, the design and preparation of biodegradable materials with excellent mechanical properties have become an urgent demand for sports medicine. In this study, biomimetic polycaprolactone (PCL)/gelatin (Gel)-aligned scaffolds were fabricated for the mechanical restoration of the injured tendon in a rabbit model. The diameter of nanofibers was about 427.82 ± 56.99 nm, which was approximate to that of the native collagen fibrils; the directional consistency of the nanofibers in PCL/Gel-aligned scaffolds reached 77.33 ± 3.22%, which were ultrastructurally biomimetic. Compared to the observations for the control group, the in vitro mechanical results showed that the PCL/Gel-aligned scaffolds (P/G-A) were anisotropic in terms of failure load, tensile strength, and Young's modulus. After verifying their good cytocompatibility, the scaffolds were implanted into the rabbit patellar tendon in situ. The biomechanical properties of the repaired tendon in P/G-A reached 343.97 ± 65.30 N in failure load, 85.99 ± 16.33 MPa in tensile strength, 590.84 ± 201.87 MPa in Young's modulus, and 171.29 ± 61.50 N mm-1 in stiffness in vivo at 8 weeks post operation. In a word, our results demonstrated that P/G-A could support the regenerated tissue of injured patellar tendons to restore the biomechanical strength in a rabbit model. This suggested that the PCL/Gel-aligned scaffolds can pave a promising way to improve the healing of injured tendons in the clinic in the future.

A Synthetic Graft With Multilayered Co-Electrospinning Nanoscaffolds for Bridging Massive Rotator Cuff Tear in a Rat Model

BACKGROUND

Graft bridging is used in massive rotator cuff tear (MRCT); however, the integration of graft-tendon and graft-bone is still a challenge.

HYPOTHESIS

A co-electrospinning nanoscaffold of polycaprolactone (PCL) with an "enthesis-mimicking" (EM) structure could bridge MRCT, facilitate tendon regeneration, and improve graft-bone healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

First, we analyzed the cytocompatibility of the electrospinning nanoscaffolds, including aligned PCL (aPCL), nonaligned PCL (nPCL), aPCL-collagen I, nPCL-collagen II, and nPCL-nanohydroxyapatite (nHA). Second, for the EM condition, nPCL-collagen II and nPCL-nHA were electrospun layer by layer at one end of the aPCL-collagen I; for the control condition, the nPCL was electrospun on the aPCL. In 40 mature male rats, resection of both the supraspinatus and infraspinatus tendons was performed to create MRCT, and the animals were divided randomly into EM and control groups. In both groups, one end of the layered structure was fixed on the footprint of the rotator cuff, whereas the other end of the layered structure was sutured with the tendon stump. The animals were euthanized for harvesting of tissues for histologic and biomechanical analysis at 4 weeks or 8 weeks postoperatively.

RESULTS

All scaffolds showed good cytocompatibility in vitro. The graft-tendon tissue in the EM group had more regularly arranged cells, denser tissue, a significantly higher tendon maturing score, and more birefringence compared with the control group at 8 weeks after operation. Newly formed fibrocartilage could be observed at the graft-bone interface in both groups by 8 weeks, but the EM group had a higher graft-bone healing score and significantly more newly formed fibrocartilage than the control group. An enthesis-like structure with transitional layers was observed in the EM group at 8 weeks. Biomechanically, the values for maximum failure load and stiffness of the tendon-graft-bone complex were significantly higher in the EM group than in the control group at 8 weeks.

CONCLUSION

The co-electrospinning nanoscaffold of aPCL-collagen I could be used as a bridging graft to improve early graft-tendon healing for MRCT in a rat model and enhance early enthesis reconstruction in combination with a multilayered structure of nPCL-collagen II and nPCL-nHA.

CLINICAL RELEVANCE

We constructed a graft to bridge MRCT, enhance graft-tendon healing and graft-bone healing, and reconstruct the enthesis structure.

Superior Capsular Reconstruction With the Long Head of the Biceps Autograft Prevents Infraspinatus Retear in Massive Posterosuperior Retracted Rotator Cuff Tears

BACKGROUND

Materials and patches with increased biomechanical and biological properties and superior capsular reconstruction may change the natural history of massive rotator cuff tears (RCTs).

PURPOSE

To compare structural and clinical outcomes among 3 surgical techniques for the treatment of massive posterosuperior RCTs: double-row (DR) technique, transosseous-equivalent (TOE) technique with absorbable patch reinforcement, and superior capsular reconstruction (SCR) with the long head of the biceps tendon (LHBT) autograft.

STUDY DESIGN

Cohort study; Level of evidence 3.

METHODS

We retrospectively analyzed the 3 techniques in patients who underwent repair of massive posterosuperior RCTs between January 2007 and March 2017. All patients completed preoperative and 24-month postoperative evaluations: range of motion, subjective shoulder value, Simple Shoulder Test, American Shoulder and Elbow Surgeons (ASES) score, visual analog scale for pain, and Constant score. Tendon integrity was assessed with ultrasound 1 year postoperatively.

RESULTS

A total of 82 patients completed the final evaluation (28 patients, DR; 30 patients, TOE + patch; 24 patients, SCR with LHBT). Groups were statistically comparable preoperatively, except for active forward elevation and tendon retraction, which were significantly worse in the SCR group (P = .008 and P = .001, respectively). After 24 months, the mean ± SD scores for the respective groups were as follows: 76 ± 10, 72 ± 15, and 77 ± 10 for the Constant score (P = .35); 84 ± 10, 84 ± 15, and 80 ± 15 for the ASES (P = .61); 9 ± 2, 9 ± 3, and 8 ± 3 for the Simple Shoulder Test (P = .23); 82 ± 15, 80 ± 18, and 75 ± 18 for the subjective shoulder value (P = .29); and 1.4 ± 1.7, 1.8 ± 2, and 1.4 ± 1.4 for the visual analog scale (P = .65). The strength of the operated shoulder was 4 ± 3 kg, 4.7 ± 3 kg, and 6.4 ± 1.6 kg for the DR, TOE + patch, and SCR groups, respectively (P = .006). At 12 months postoperatively, 60.7% (17 of 28) of the DR group, 56.7% (17 of 30) of the TOE + patch group, and 91.7% (22 of 24) of the SCR group remained healed on ultrasound. The infraspinatus tendon remained healed in 75% of the DR group, 76.5% of the TOE + patch group, and 100% of the SCR with the LHBT group (P = .006).

CONCLUSION

In cases of massive posterosuperior RCTs, SCR with the LHBT should be considered a reliable, cost-effective treatment option that protects infraspinatus integrity.

Stem Cells in Rotator Cuff Injuries and Reconstructions: A Systematic Review and Meta-Analysis

BACKGROUND

Multiple studies have focused on stem cell-based treatments for rotator cuff disorders; however, the outcomes are not consistent.

OBJECTIVES

This systematic review and meta-analysis were performed to evaluate the effects of stem cells on rotator cuff healing.

METHODS

A detailed search of relevant studies was conducted in three databases including Pubmed/ Medline, Cochrane library, and Embase databases, using the following keywords: "rotator cuff" or "Tissue Engineering" AND "stem cell" from inception to January 01, 2019. The standard mean difference (SMD) and 95% confidence interval (CI) for each individual study were extracted from the original studies or calculated based on relevant data and pooled to obtain integrated estimates using random effects modeling.

RESULTS

A total of 22 studies were identified. The results demonstrated that the ultimate strain in the stem cell group was significantly higher than that in the control group at 4 and 8 weeks. Muscle weight in the stem cell group was higher than the control group at 8 weeks, while no significant differences were detected at 16 weeks. The stem cell group had lower visual analog scale scores (VAS) at 1, 3, and 6 months, and higher American shoulder and elbow surgeons score (ASES) at 3 months. In addition, the walking distance, time, and speed in the stem cell group were significantly superior to those in the control group.

CONCLUSIONS

This meta-analysis confirms that stem cells improved the rehabilitation of rotator cuff disorders. However, larger-scale studies are needed to further support these findings.