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

A composite PET-matrix patch enhances tendon regeneration and tendon-to-bone integration for bridging repair of the chronic massive rotator cuff tears in a rabbit model

In recent years, bridging repair has emerged as an effective approach for the treatment of massive rotator cuff tears (MRCTs). The objective of this study was to develop a composite patch that combines superior mechanical strength and biocompatibility and evaluate its potential for enhancing the outcomes of bridging repair for MRCTs. The composite patch, referred to as the PET-matrix patch (PM), was fabricated by immersing a plain-woven PET patch in decellularized matrix gel and utilizing the freeze-drying technique. The results demonstrated that the PM has reliable mechanical properties, with a maximum failure load of up to 480 N. The decellularized matrix sponge (DMS), present on the surface of the PM, displayed a loose and porous structure, with an average pore size of 62.51 μm and a porosity of 95.43%. In vitro experiments showed significant elongation of tenocytes on the DMS, with cells spanning across multiple pores and extending multiple protrusions as observed on SEM images. In contrast, tenocytes on the PET patch appeared smaller in size and lacked significant elongation. Additionally, the DMS facilitated the proliferation, migration and differentiation of tenocytes. In a rabbit model of chronic MRCTs, the PM group showed superior outcomes compared to the PET group at 4, 8 and 12 weeks after bridging repair. The PM group displayed significantly higher tendon maturing score, larger collagen diameter in the regenerated tendon and improved tendon-to-bone healing scores compared to the PET group (P < 0.05). Moreover, the maximum failure load of the tendon-bone complex in the PM group was significantly higher than that in the PET group (P < 0.05). In summary, the PM possesses reliable mechanical properties and excellent cytocompatibility, which can significantly improve the outcomes of bridging repair for chronic MRCTs in rabbits. Therefore, it holds great potential for clinical applications.

An Unconventional Solution for Persistent Lateral Hip Prosthetic Friction Syndrome (LHPFS) after Revision Total Hip Arthroplasty

We report on a 77-year-old male patient, who presented with excessive bone loss at the area of the greater trochanter after several hip revision surgeries resulting in a persistent friction syndrome caused directly by the rough surface and sharp edges of the prosthetic shoulder of a well-fixed Wagner-type revision stem. Surgery was performed by creating a cemented neotrochanter with an attached polyester patch around the proximal lateral shaft and performing a Z-plasty of the iliotibial tract. Twelve months postoperatively, the patient reported a reduction in subjective pain of 50% and improvement of the Harris Hip Score from 45 to 75 points. Without a definition in the current literature, the authors propose the term "lateral hip prosthetic friction syndrome" (LHPFS) to describe this medical condition.

Histologic and biomechanical comparison of fascia lata autograft, acellular dermal xenograft, and synthetic patch for bridging massive rotator cuff tear in a rabbit model

Background

Bridging repair has emerged as a promising and reliable treatment strategy for the massive rotator cuff tears (MRCTs). However, there remains a lack of evidence on which bridging graft provides the better repair results, and a dearth of animal studies comparing bridging repairs with different grafts. The purpose of this study was to evaluate the histological and biomechanical outcomes of commonly used grafts (autologous fascia lata (FL), acellular dermal matrix graft (ADM), and polyethylene terephthalate (PET) patch).

Methods

A total of 66 male New Zealand White Rabbits were used to mimic a model of unilateral chronic MRCTs. The rabbits were randomly divided into three groups: (1) FL group, which underwent bridging repair with autologous FL; (2) ADM group, which underwent bridging with ADM; and (3) PET group, which underwent bridging with PET patch. Tissue samples were collected and subjected to histological analysis using Hematoxylin and eosin, Picrosirius red, Safranin O/Fast green staining, and Immunostaining. Collagen diameter and fibril density in the regenerated tendon was analyzed with transmission electron microscopy (TEM). Additionally, biomechanical tests were performed at 6 and 12 weeks after repair.

Results

The regenerated tendon successfully reattached to the footprint in all experimental groups. At 6 weeks after repair, the FL group had a significantly higher Modified Tendon Histological Evaluation (MTHE) score at the regenerated tendon than the PET group (13.2 ± 1.64 vs 9.6 ± 1.95, respectively; P = 0.038). The picrosirius red staining results showed that the FL group had a significantly higher type I collagen content than the ADM and PET groups at 6 weeks, and this difference was sustained with the PET group at 12 weeks (P < 0.05). Immunofluorescence analysis against CD68 indicated that the number of macrophage infiltrates was significantly lower in the FL group than in the ADM and PET groups (P < 0.05). At 12 weeks after repair, the area of Safranin O metachromasia was significant greater in ADM group than that in the PET group (P = 0.01). The FL group showed a significantly larger collagen diameter in the regenerated tendon than the PET group (P < 0.05), as indicated by TEM results. Furthermore, the FL group resulted in a greater failure load (at 6 weeks; 118.40 ± 16.70 N vs 93.75 ± 9.06 N, respectively; P = 0.019) and elastic modulus (at 6 weeks; 12.28 ± 1.94 MPa vs 9.58 ± 0.79 MPa, respectively; P = 0.024; at 12 weeks; 15.02 ± 2.36 MPa vs 11.63 ± 1.20 MPa, respectively; P = 0.032) than the ADM group.

Conclusions

This study demonstrated that all three grafts could successfully bridging chronic MRCTs in a rabbit model. However, autologous FL promoted tendon regeneration and maturation, and enhanced the tensile properties of the tendon-to-bone complex when compared with ADM and PET grafts.

Application of Nondegradable Synthetic Materials for Tendon and Ligament Injury

Tendon and ligament injuries, prevalent requiring surgical intervention, significantly impact joint stability and function. Owing to excellent mechanical properties and biochemical stability, Nondegradable synthetic materials, including polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE), have demonstrated significant potential in the treatment of tendon and ligament injuries. These above materials offer substantial mechanical support, joint mobility, and tissue healing promotion of the shoulder, knee, and ankle joint. This review conclude the latest development and application of nondegradable materials such as artificial patches and ligaments in tendon and ligament injuries including rotator cuff tears (RCTs), anterior cruciate ligament (ACL) injuries, and Achilles tendon ruptures.

Rotator Cuff Repair and Overlay Augmentation by Direct Interlocking of a Nonwoven Polyethylene Terephthalate Patch Into the Tendon: Evaluation in an Ovine Model

BACKGROUND

Arthroscopic repair of large rotator cuff tendon tears is associated with high rates of retear. Construct failure often occurs at the suture-tendon interface. Patch augmentation can improve mechanical strength and healing at this interface.

PURPOSE

To introduce a novel technique for suture-free attachment of an overlaid patch and evaluate its biomechanical strength and biological performance.

STUDY DESIGN

Descriptive and controlled laboratory studies.

METHODS

An established ovine model of partial infraspinatus tendon resection and immediate repair was used. After a nonwoven polyethylene terephthalate patch was overlaid to the resected tendon, a barbed microblade was used to draw fibers of the patch directly into the underlying tissue. In vivo histological assessment of healing was performed at 6 and 13 weeks after implantation. Ex vivo models were used to characterize primary repair strength of the suture-free patch fixation to tendon. Additional ex vivo testing assessed the potential of the technique for patch overlay augmentation of suture-based repair.

RESULTS

The in vivo study revealed no macroscopic evidence of adverse tissue reactions to the interlocked patch fibers. Histological testing indicated a normal host healing response with minimal fibrosis. Uniform and aligned tissue ingrowth to the core of the patch was observed from both the tendon and the bone interfaces to the patch. There was no evident retraction of the infraspinatus muscle, lengthening of the tendon, or tendon gap formation over 13 weeks. Ex vivo testing revealed that direct patch interlocking yielded tendon purchase equivalent to a Mason-Allen suture (150 ± 58 vs 154 ± 49 N, respectively; P = .25). In an overlay configuration, fiber interlocked patch augmentation increased Mason-Allen suture retention strength by 88% (from 221 ± 43 N to 417 ± 86 N; P < .01) with no detectable difference in repair stiffness.

CONCLUSION

Testing in an ovine model of rotator cuff tendon repair suggested that surgical interlocking of a nonwoven medical textile can provide effective biomechanical performance, support functional tissue ingrowth, and help avoid musculotendinous retraction after surgical tendon repair.

CLINICAL RELEVANCE

The novel technique may facilitate patch augmentation of rotator cuff repairs.

Massive rotator cuff tears with short tendon length can be successfully repaired using synthetic patch augmentation

BACKGROUND

Choosing the optimal treatment for massive rotator cuff tears (MRCTs) still poses a surgical problem. In MRCTs with good muscle quality, but short tendon length, nonaugmented repairs lead to high failure rates of up to 90%. The aim of the study was to evaluate midterm clinical and radiologic outcomes of massive rotator cuff tears with good muscle quality, but short tendon length, which were repaired with synthetic patch augmentation.

METHODS

A retrospective study of patients who underwent arthroscopic or open rotator cuff repairs with patch augmentation between 2016 and 2019 was performed. We included patients older than 18 years, who presented with an MRCT confirmed by an magnetic resonance imaging (MRI) arthrogram showing good muscle quality (Goutallier ≤ II) and short tendon length (length <15 mm). Constant-Murley score (CS), Subjective Shoulder Value (SSV), and range of motion (ROM) were compared pre- and postoperatively. We excluded patients older than 75 years or with presence of rotator cuff arthropathy Hamada stage ≥2a. Patients were followed up for 2 years minimum. Clinical failures were defined by reoperation, forward flexion <120° or a relative CS < 70. Structural integrity of the repair was assessed using an MRI scan. Comparison between different variables and outcomes was performed using Wilcoxon-Mann-Whitney and χ2 tests.

RESULTS

Fifteen patients (mean age 57 years, 13 [86.7%] male, 9 [60%] right shoulders) were reevaluated with a mean follow-up of 43.8 months (27-55 months). There was a significant improvement in the absolute CS (from 33 to 81 points, P = .03), the relative CS (from 41% to 88%, P = .04), the SSV (from 31% to 93%, P = .007), and forward flexion (from 111° to 163°, P = .004) but not in external rotation (from 37° to 38°, P = .5). There were 3 clinical failures (1 atraumatic, 2 traumatic) with reoperations (2 reverse total shoulder arthroplasties and 1 refixation). Structurally, there were 3 Sugaya grade 4 and 5 Sugaya grade 5 reruptures resulting in a retear rate of 53%. The presence of a complete or partial rerupture was not associated with inferior outcomes compared with intact cuff repairs. There were no correlations between the grade of retraction, muscle quality, or rotator cuff tear configuration and rerupture or functional outcomes.

CONCLUSION

Patch augmented cuff repair leads to a significant improvement of functional and structural outcomes. Partial reruptures were not associated with inferior functional outcomes. Prospective randomized trials are needed to confirm the results found in our study.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Incidence of Postoperative Shoulder Stiffness After Arthroscopic Rotator Cuff Repair: A Systematic Review

Rotator cuff tear (RCT) is a common shoulder condition frequently treated with arthroscopic rotator cuff repair (ARCR) after conservative interventions have failed. Postoperative shoulder stiffness (POSS) is a common complication after ARCR. The purpose of this study is to determine the incidence of POSS after ARCR in total and based on tear extent prior to ARCR. A systematic review was performed using PubMed, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Medical Literature Analysis and Retrieval System Online (MEDLINE), and ScienceDirect databases. The search terms were "rotator cuff repair" AND "arthrofibrosis" OR "postoperative shoulder stiffness." Articles were selected based on ARCR and the presence of POSS documentation. Twenty-five articles out of 284 articles met the final selection criteria after reviewing for patients who received ARCR. Out of all patients (n=9,373), 597 had POSS (6.4%). Out of the 2,424 patients with a specified tear pattern, 96 out of 1,862 (5.2%) patients with full-thickness tears and 58 out of 562 (10.3%) patients with partial-thickness tears had POSS after ARCR. Partial-thickness tears are associated with higher rates of POSS after ARCR as compared to full-thickness tears (p<0.001). Overall, POSS is a common complication after ARCR with an incidence of 6.4%, regardless of tear type. POSS is more common in patients who receive ARCR for partial-thickness RCT (10.3%) as compared to patients who receive ARCR for full-thickness RCT (5.2%). More research is needed to determine other factors impacting the incidence of POSS after ARCR.

A Knitted PET Patch Enhances the Maturation of Regenerated Tendons in Bridging Reconstruction of Massive Rotator Cuff Tears in a Rabbit Model

BACKGROUND

Although nondegradable synthetic grafts for bridging reconstruction of massive rotator cuff tears (MRCTs) have shown satisfactory clinical outcomes, their function and details on graft-tendon healing and enthesis regeneration have not been fully studied.

HYPOTHESIS

The knitted polyethylene terephthalate (PET) patch as a nondegradable synthetic graft could provide sustained mechanical support, facilitating enthesis and tendon regeneration in the treatment of MRCTs.

STUDY DESIGN

Controlled laboratory study.

METHODS

A knitted PET patch was fabricated for bridging reconstruction (PET group) in a New Zealand White rabbit model of MRCTs (negative control group), and an autologous Achilles tendon was used as a control (autograft group). The animals were sacrificed, and tissue samples were harvested for gross observation as well as histological and biomechanical analyses at 4, 8, and 12 weeks postoperatively.

RESULTS

Histological analysis showed no significant difference in the graft-bone interface score between the PET and autograft groups at 4, 8, and 12 weeks postoperatively. Interestingly, in the PET group, Sharpey-like fibers were observed at 8 weeks, while fibrocartilage formation and the ingrowth of chondrocytes were recognized at 12 weeks. Meanwhile, the tendon maturing score was significantly higher in the PET group than in the autograft group (19.7 ± 1.5 vs 15.3 ± 1.2, respectively; P = .008) at 12 weeks, with parallel-oriented collagen fibers around the knitted PET patch. Moreover, the ultimate failure load of the PET group was similar to that of a healthy rabbit tendon at 8 weeks (125.6 ± 13.6 vs 130.8 ± 28.6 N, respectively; P > .05) and no different from that of the autograft group at 4, 8, and 12 weeks.

CONCLUSION

The knitted PET patch could not only immediately reconstruct the mechanical support for the torn tendon postoperatively in the rabbit model of MRCTs but also enhanced maturation of the regenerated tendon by fibrocartilage formation and improved the organization of collagen fibers. Herein, the knitted PET patch could be a promising candidate graft adopted in bridging reconstruction of MRCTs.

CLINICAL RELEVANCE

A nondegradable knitted PET patch can safely bridge MRCTs with satisfactory mechanical strength and the promotion of tissue regeneration.

Management of Massive Rotator Cuff Tears Without Arthropathy

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

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

Background:

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

Purpose:

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

Study Design:

Systematic review; Level of evidence, 1.

Methods:

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

Results:

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

Conclusion:

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

Comparison of Superior Capsular Reconstruction and Partial Infraspinatus Repair: A Matched-Pair Analysis of Irreparable Rotator Cuff Tears

Background

Superior capsular reconstruction (SCR) represents a new option for the treatment of irreparable rotator cuff tears.

Purpose/Hypothesis

This study aimed to evaluate the clinical and radiologic outcomes of SCR and compare them with the outcomes of partial repair (PR) of the infraspinatus tendon. The hypothesis was that there would be no significant differences between the clinical and radiologic outcome parameters of SCR and PR after a minimum follow-up of 2 years.

Study Design

Cohort study; Level of evidence, 3.

Methods

Of 21 patients who underwent SCR, 20 patients were matched in a 1:1 ratio according to sex, age, and tear configuration with 20 of 60 patients who had undergone PR; all patients were prospectively evaluated for a minimum follow-up of 2 years. The investigated outcome measures included the Constant score; Western Ontario Rotator Cuff (WORC) index; Disabilities of the Arm, Shoulder and Hand (DASH) score; and radiologic analysis of acromiohumeral distance (AHD) and humeral head centralization (HHC).

Results

There were no differences in the demographic data between the SCR and PR groups. The mean age of both groups was 62.3 years (range, 47-79 years), the mean tear configuration was Bateman 3.0 and Patte 2.8, and the mean follow-up period was 29.4 months (range, 24-53 months). At final follow-up, no significant differences were seen between the SCR and PR groups with regard to Constant score (77.1 vs 82.7), age- and sex-adapted Constant score (85.5% vs 91.4%), DASH score (15.6 vs 7.8), or WORC index (81.1 vs 90.4). No significant differences in the AHD or HHC were seen between the groups. The reoperation rate was 4.8% (1/21) in the SCR cohort and 15% (9/60) in the PR cohort.

Conclusion

Both SCR and PR resulted in significant improvements in patient-reported outcomes at 2-year follow-up, with no significant differences in clinical outcomes between the 2 techniques. Further follow-up is needed to determine whether there are long-term differences in HHC and development of cuff tear arthropathy. Further investigations should also focus on the cost-effectiveness of the respective procedures.

[Research progress of treatment for massive rotator cuff tears]

Objective

To review the research progress of treatment for massive rotator cuff tears.

Methods

The domestic and foreign literature about the treatment of massive rotator cuff tears was reviewed. The methods and effectiveness were extensively summarized.

Results

The treatment of massive rotator cuff tears still needs long-term research to promote its continuous improvement. The main goal of treatment is to relieve the symptoms and improve the shoulder joint function. With the development of arthroscopic technique, arthroscopic repair of rotator cuff tears has become a mature surgical protocol. Among these techniques, superior capsule reconstruction and patch augmentation for massive rotator cuff tears acquire more attention in recent years. As for rotator cuff arthropathy, reverse shoulder arthroplasty is considered to be a final choice.

Conclusion

Surgical treatment is the main choice for massive rotator cuff tears. Patients' age and muscle condition should be taken into consideration to decide the surgical technique.

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.