Reinforced fascia patch limits cyclic gapping of rotator cuff repairs in a human cadaveric model

Biomechanical comparison of suture bridge rotator cuff repair with and without dermal allograft pledgets

BACKGROUND

One method to augment rotator cuff repair is to pass dermal allograft pledgets along the sutures that bridge from the medial to the lateral row. It remains unclear whether this augmentation method alters repair biomechanics.

METHODS

This was a controlled laboratory study. After an a priori power analysis, 9 pairs of rotator cuffs underwent double-row suture bridge rotator cuff repair, half randomized to augmentation with dermal allograft pledgets passed along the suture bridge sutures. Repairs were then mounted on a material testing system and loaded cyclically 500 cycles to measure applied force and displacement. Repairs then underwent ultimate failure testing, and stiffness, ultimate failure force, and ultimate failure displacement were measured. Paired t tests were performed to compare between groups.

RESULTS

There were no differences between groups in construct gapping with cyclic loading after 500 cycles (P = .885). There were no differences between the augmented and control groups in yield force (103.5 ± 5.0 vs. 101.4 ± 5.9 N, respectively, P = .183), stiffness (94.2 ± 13.9 vs. 90.9 ± 13.8, P = .585), or ultimate failure force (255.3 ± 65.8 vs. 285.3 ± 83.2, P = .315). There were no differences between groups in failure modes, with most specimens failing by cuff tissue tearing within or medial to the construct.

CONCLUSION

The addition of dermal allograft pledgets does not positively or negatively influence the time-zero biomechanical characteristics of double-row suture bridge rotator cuff repair.

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

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

Clinical outcomes of medialized single-row repair with fascia lata graft augmentation for large and massive rotator cuff tears

BACKGROUND

A high postoperative retear rate after arthroscopic rotator cuff repair (ARCR) of large and massive tears remains a problem. This study evaluated rotator cuff integrity after ARCR with fascia lata graft augmentation for large and massive rotator cuff tears and compared clinical outcomes between patients with intact repairs and retears.

METHODS

Forty-five patients with rotator cuff tears who could not undergo primary repair due to tendon retraction underwent arthroscopic medialized single-row repair with fascia lata graft augmentation. The patients' minimum follow-up was 2 (2-9) years. Supraspinatus cuff integrity was evaluated postoperatively by magnetic resonance imaging. We compared the clinical outcomes of patients with intact repairs vs. retears based on the University of California-Los Angeles (UCLA), Constant, and Japanese Orthopaedic Association (JOA) scores. We also evaluated their range of motion (ROM) and muscle strength.

RESULTS

Retears were observed in 11 of 45 patients. UCLA, Constant, and JOA scores significantly improved postoperatively compared to preoperatively in the intact repair (all P < .001) and retear (all P < .036) groups. The intact repair group had significantly higher Constant (75.6 [mean] ± 9.9 [SD] vs. 69.8 ± 7.9; P = .026) and JOA (94.4 ± 6.9 vs. 89.8 ± 5.9; P = .041) scores than the retear group. Forward elevation, abduction, and the strengths of abduction and external rotation significantly improved in the intact repair group (all P < .003) but not in the retear group (all P > .05). The intact repair group had significantly higher postoperative forward flexion (165° ± 15° vs. 154° ± 23°; P = .036), abduction (164° ± 17° vs. 151° ± 26°; P = .029), and abduction strength (3.5 ± 2.2 kg vs. 2.3 ± 1.2 kg; P = .017) than the retear group. In the intact repair group (n = 34), Sugaya type I:II ratio differed significantly between postoperative 3 months (2:32) and 24 months (24:10) (P < .001). Repaired tendon thickness did not decrease significantly between 3 months (7.1 mm) and 2 years (6.9 mm) (P = .543).

CONCLUSIONS

ARCR with fascia lata graft augmentation of large and massive rotator cuff tears showed a 24.4% retear rate but significantly improved the clinical scores, ROMs, and muscle strength with excellent cuff integrity in the intact repair group. However, the differences in the Constant and UCLA scores between the intact repair and retear groups were under the minimal clinically important difference, and their clinical significance is uncertain. Our results confirm that ARCR with fascia lata graft augmentation improves patients' postoperative outcomes if the repair site is maintained postoperatively.

Graft Augmentation of Rotator Cuff Repair Improves Load to Failure But Does Not Affect Stiffness or Gap Formation: A Meta-analysis of Biomechanical Studies

PURPOSE

To examine the biomechanical properties of rotator cuff repair with graft augmentation (RCR-G) with regard to ultimate load to failure, gap displacement, and stiffness.

METHODS

A systematic review was performed by searching PubMed, the Cochrane library, and Embase using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that analyzed the biomechanical properties of RCR-G. The search string implemented used the concepts "rotator cuff" and "graft," and "biomechanical" OR "cadaver." Meta-analysis was performed to provide a quantitative comparison of the 2 techniques. Primary outcome measures were ultimate load to failure (N), gap displacement (mm), and stiffness (N/mm).

RESULTS

Our initial search yielded 1,493 articles for review. Following screening for inclusion criteria, 8 studies were included in the meta-analysis, including a total of 191 cadaveric specimens (106 RCR-G, 85 RCR). The pooled analysis from 6 studies reporting on ultimate load to failure revealed a statistically significant difference in favor of RCR-G compared with RCR (P < .001). Pooled analysis from 6 studies reporting on gap displacement failed to reveal a difference between RCR-G and RCR (P = .719). Pooled analysis from 4 studies reporting on stiffness failed to reveal a difference between RCR-G and RCR (P = .842).

CONCLUSIONS

Graft augmentation of RCR in vitro resulted in significantly increased ultimate load to failure, with no influence on gap formation or stiffness.

CLINICAL RELEVANCE

The biomechanical advantage of RCR with graft augmentation demonstrated via increased ultimate load to failure in cadaveric studies may provide an explanation for the decreased RCR retear rates and improved patient reported outcomes reported in the clinical literature regarding graft augmentation.

Rotator cuff repair with an interposition polypropylene mesh: A biomechanical ovine study

BACKGROUND

Chronic large to massive rotator cuff tears are difficult to treat and re-tears are common even after surgical repair. We propose using a synthetic polypropylene mesh to increase the tensile strength of rotator cuff repairs. We hypothesize that using a polypropylene mesh to bridge the repair of large rotator cuff tears will increase the ultimate failure load of the repair.

AIM

To investigate the mechanical properties of rotator cuff tears repaired with a polypropylene interposition graft in an ovine ex-vivo model.

METHODS

A 20 mm length of infraspinatus tendon was resected from fifteen fresh sheep shoulders to simulate a large tear. We used a polypropylene mesh as an interposition graft between the ends of the tendon for repair. In seven specimens, the mesh was secured to remnant tendon by continuous stitching while mattress stitches were used for eight specimens. Five specimens with an intact tendon were tested. The specimens underwent cyclic loading to determine the ultimate failure load and gap formation.

RESULTS

The mean gap formation after 3000 cycles was 1.67 mm in the continuous group, and 4.16 mm in the mattress group (P = 0.001). The mean ultimate failure load was significantly higher at 549.2 N in the continuous group, 426.4 N in the mattress group and 370 N in the intact group (P = 0.003).

CONCLUSION

The use of a polypropylene mesh is biomechanically suitable as an interposition graft for large irreparable rotator cuff tears.

Current Understanding and New Advances in the Surgical Management of Reparable Rotator Cuff Tears: A Scoping Review

Rotator cuff (RC) tears are among the most common musculoskeletal disorders and can be associated with pain, weakness, and shoulder dysfunction. In recent years, there have been significant advances with regard to the understanding of rotator cuff disease and its management. With technological improvements and advanced diagnostic modalities, there has been much progress as to improved understanding of the pathology. Similarly, with advanced implant designs and instrumentation, operative techniques have evolved. Furthermore, refinements in postoperative rehabilitation protocols have improved patient outcomes. In this scoping review, we aim to provide an overview of the current knowledge on the treatment of rotator cuff disorders and to highlight recent advances in its management.

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.].

A collagen/PLA hybrid scaffold supports tendon-derived cell growth for tendon repair and regeneration

A rotator cuff tendon tear is a common shoulder injury with a relatively high rate of recurrence after surgical repair. In order to reinforce the repair and reduce the risk of clinical complications, a patch scaffold is typically sutured over the tendon tear to provide post-surgical mechanical support. However, despite considerable research effort in this area, a patch scaffold that provides both superior initial mechanical properties and supports cell proliferation at the same time has not yet been achieved. In this study, we engineered a collagen/poly(lactic acid) (COL/PLA) hybrid yarn to leverage mechanical strength of PLA yarn and the bioactivity of collagen. The COL/PLA yarns were used to fabricate a tissue engineering scaffold using textile weaving technology. This hybrid scaffold had a tensile strength of 354.0 ± 36.0 N under dry conditions and 267.2 ± 15.9 N under wet conditions, which was satisfactory to maintain normal tendon function. By introducing COL yarns into the hybrid scaffold, the proliferation of tendon-derived cells was significantly improved on the scaffold. Cell coverage after 28-days of in vitro cell culture was noticeably higher on the COL yarns compared to the PLA yarns as a result of a larger number of cells and more spread cell morphology on collagen. Cells spread in multiple directions on COL yarns, which resembled a more natural cell attachment on extracellular matrix. On the contrary, the cells attached to the PLA filaments presented an elongated morphology along the fiber's axial direction. Combining the mechanical robustness of PLA and the biological activity of collagen, the woven COL/PLA hybrid scaffold has shown its potential to be a promising candidate for tendon repair applications.

Aktuelle Aspekte der Behandlung der Rotatorenmanschette

Rotatorenmanschettenrupturen gehören zu den häufigsten muskuloskeletalen Erkrankungen und können mit ausgeprägten Schmerzen und Funktionseinschränkungen einhergehen. Für ihre Entstehung ist eine Vielzahl von Faktoren relevant, u. a. die individuelle Anatomie des Akromions. Mit Hilfe der heutigen technischen Möglichkeiten wurde nun festgestellt, dass zusätzlich zu seiner lateralen Ausdehnung auch die sagittale Ausdehnung des Akromions eine Rolle zu spielen scheint. Die bildgebende Darstellung der Rotatorenmanschette (RM) hat von den technischen Fortschritten der letzten Jahrzehnte ebenfalls profitiert. Magnetresonanztomographie (MRT) und MR-Arthrographie werden heute flächendeckend eingesetzt. Letztere bietet die höchste Sensitivität für die Entdeckung selbst kleiner Partialläsionen. Neue Sequenzen und Nachbearbeitungsmöglichkeiten können als hilfreiche tools für die operative Planung eingesetzt werden. Grundsätzlich richtet sich die Behandlung der RM neben der Symptomatik nach der Rupturgenese und -morphologie sowie der erwarteten Gewebequalität des Muskel-Sehnen-Kontinuums. Auch das Gesamtprofil, die Erwartungshaltung und die Rehabilitationsmöglichkeiten des Patienten sind wichtig. Die heutigen operativen Techniken werden durch spannende Entwicklungen der Industrie mitbestimmt, die in den letzten Jahren immer bessere Fadenankersysteme, aber auch Augmentationsmaterialien auf den Markt gebracht hat. Letztere zielen nicht nur auf die mechanische Verstärkung der Sehnenrekonstruktion, sondern auch auf die Optimierung der biologischen Eigenschaften des Konstrukts ab. Hinsichtlich Fixation konnte die biomechanische Forschung zeigen, dass zweireihige oder Suture-Bridge-Fixationen einreihigen oder transossären Fixationen überlegen sind. Diese Überlegenheit im Labor spiegelt sich noch nicht klar in den klinischen Ergebnissen wider, dennoch sind die meisten Chirurgen heute auf diese Technik übergegangen. Was die postoperative Nachbehandlung angeht, stellen jüngste randomisiert-kontrollierte Untersuchungen das Konzept der postoperativen Immobilisation in Abduktion in Frage. Hier scheint das letzte Wort noch nicht gesprochen zu sein.

[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.

Tendon-Inspired Nanotopographic Scaffold for Tissue Regeneration in Rotator Cuff Injuries

Acute and chronic rotator cuff (RC) tears are common etiologies of shoulder disabilities. Despite the advanced surgical techniques and graft materials available for tendon repair, the high re-tear rate remains a critical challenge in RC healing. Inspired by the highly organized nanotopography of the extracellular matrix (ECM) in tendon tissue of the shoulder, nanotopographic scaffolds are developed using polycaprolactone for the repair and regeneration of RC tendons. The scaffolds show appropriate flexibility and mechanical properties for application in tendon tissue regeneration. It is found that the highly aligned nanotopographic cues of scaffolds could sensitively control and improve the morphology, attachment, proliferation, and differentiation of tendon-derived cells as well as promote their wound healing capacity in vitro. In particular, this study showed that the scaffolds could promote tendon regeneration along the direction of the nanotopography in the rabbit models of acute and chronic RC tears. Nanotopographic scaffold-augmented rotator cuff repair showed a more appropriate healing pattern compared to the control groups in a rabbit RC tear model. We demonstrated that the tendon ECM-like nanoscale structural cues of the tendon-inspired patch may induce the more aligned tissue regeneration of the underlying tissues including tendon-to-bone interface.

Biomechanical Effects of Fiber Patch Augmentation on Rotator Cuff Repairs

Rotator cuff repairs are a common orthopedic procedure that have a relatively high failure rate when tendon quality is poor. New biotechnology exists that can make tendons with poor quality more amenable to repair. This study examined the biomechanical effects of augmenting a rotator cuff repair with an absorbable fiber patch. Six human cadaveric supraspinatus tendons were prepared into 1-cm wide strips and then repaired to the rotator cuff footprint using a titanium anchor and a single mattress suture. Each shoulder underwent repair with and without a fiber patch. The specimens were subjected to cyclic loading (100 cycles) and load-to-failure (LTF) testing. Gap formation after 100 cycles was measured along with LTF in surviving specimens. Gap formation after 100 cycles was 1.07 mm in the suture-only group and 0.50 mm in the fiber patch-augmented group (P=.002). Load-to-failure was 54.26 N in the suture-only group and 109.53 N in the patch-augmented group (P<.001). The use of a fiber patch to augment rotator cuff repair reduced gap formation and increased LTF. [Orthopedics. 2020; 43(1):42-45.].

Bone healing potential of fascia lata autografts to the humeral head footprint in rotator cuff reconstruction based on magnetic resonance imaging and histologic evaluations

BACKGROUND

The purpose of the study was to evaluate the bone healing potential of fascia lata autograft (FLA) by magnetic resonance imaging (MRI) and histologic analysis.

METHODS

The study included 69 patients assessed by MRI after an FLA patch procedure. Three of the 69 patients underwent a revision procedure after the primary FLA procedure; 1 underwent a second-look arthroscopy and 2 underwent reverse shoulder arthroplasties (RSAs). In the 2 RSA patients, we histologically evaluated greater tuberosities with the repaired graft. Moreover, as a control, we harvested the greater tuberosity with the cuff tendon at the time of RSA for failed open reduction-internal fixation of 4-part proximal humeral fracture. Based on MRI, retear cases were divided into type 1 (the graft did not remain on the greater tuberosity) and type 2 (the graft remained on the greater tuberosity). Histologic sections were evaluated to examine fascia-bone or rotator cuff-bone interfaces.

RESULTS

There were 35 intact repairs: 7 type 1 and 27 type 2 shoulders (type 1 vs. type 2, P < .001). Second-look arthroscopic findings confirmed that the graft was securely attached to the greater tuberosity. Histologic analysis of greater tuberosities in RSA patients showed solid continuity of the graft to the bone, with cells with nuclei in the collagen matrix oriented in parallel. The FLA to bone junction consisted of the FLA, fibrocartilage, and bone, which is similar to the normal cuff tendon to bone junction.

CONCLUSIONS

These results indicate that a fresh cellular FLA has good to excellent bone healing potential.

Rotator cuff tear healing process with graft augmentation of fascia lata in a rabbit model

Background

Fascia lata augmentation of massive rotator cuff tears has shown good clinical results. However, its biological effect during the early healing process is not clearly understood. The purpose of the study was to evaluate the biological efficacy of fascia lata augmentation during the early healing process of rotator cuff tears using a rabbit rotator cuff defect model.

Methods

The infraspinatus tendon was resected from the greater tuberosity of a rabbit to create a rotator cuff tear. The tendon edge was directly sutured to the humeral head. The rotator cuff repaired site was augmented with a fascia lata autograft (augmentation group, group A). The rotator cuff defect in the contralateral shoulder was repaired without augmentation (reattachment group, group R). A group with intact rotator cuff was set as the control group. Histological examinations and mechanical analysis were conducted 4 and 8 weeks postoperatively.

Results

In the HE staining, the tendon maturing score of group A was higher than that of group R at 4 weeks postoperatively. In the safranin O staining, proteoglycan staining at the repaired enthesis in group A at 4 weeks postoperatively was stronger than that in group R. Picrosirius red staining showed that type III and type I collagen in group A was more strongly expressed than that in group R at 4 weeks postoperatively. The ultimate failure load of the infraspinatus tendon–humeral head complex in group A was statistically higher than that in group R at 4 weeks postoperatively. The ultimate failure load of group A was similar to that of the control group.

Conclusion

The biological and mechanical contribution of fascia lata augmentation for massive rotator cuff tears was analyzed in this study. Type III collagen was reported to be expressed during the tendon healing process. Although the biological action similar to natural ligament healing occurred around the fascia lata grafts, type III collagen was gradually replaced by type I collagen as the tissue matured. Our results suggest that fascia lata augmentation could stimulate biological healing and provide initial fixation strength of the repaired rotator cuff.

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.

Regenerative Engineering of the Rotator Cuff of the Shoulder

Rotator cuff tears often heal poorly, leading to re-tears after repair. This is in part attributed to the low proliferative ability of the resident cells (tendon fibroblasts and tendon-stem cells) upon injury to the rotator cuff tissue and the low vascularity of the tendon insertion. In addition, surgical outcomes of current techniques used in clinical settings are often suboptimal, leading to the formation of neo-tissue with poor biomechanics and structural characteristics, which results in re-tears. This has prompted interest in a new approach, which we term as "Regenerative Engineering", for regenerating rotator cuff tendons. In the Regenerative Engineering paradigm, roles played by stem cells, scaffolds, growth factors/small molecules, the use of local physical forces, and morphogenesis interplayed with clinical surgery techniques may synchronously act, leading to synergistic effects and resulting in successful tissue regeneration. In this regard, various cell sources such as tendon fibroblasts and adult tissue-derived stem cells have been isolated, characterized, and investigated for regenerating rotator cuff tendons. Likewise, numerous scaffolds with varying architecture, geometry, and mechanical characteristics of biologic and synthetic origin have been developed. Furthermore, these scaffolds have been also fabricated with biochemical cues (growth factors and small molecules), facilitating tissue regeneration. In this Review, various strategies to regenerate rotator cuff tendons using stem cells, advanced materials, and factors in the setting of physical forces under the Regenerative Engineering paradigm are described.

Editorial Commentary: Don't Pig Out When Selecting a Shoulder, Rotator Cuff Augmentation Graft! Xenografts Are Not the Way to Go

Porcine xenograft dermal onlay augmentation of rotator cuff repair does not provide improved cuff integrity or provide better clinical outcomes. The retear rate was actually higher in repairs augmented with a porcine xenograft than the control group. Adverse events occurred in 60% of the xenograft patients compared with 40% of the controls. The use of liquid platelet-rich plasma had no discernible impact. A total of 85% of the observed failures with the suture-bridging double-row repair were at the medial cuff (Cho type 2).

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.

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

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

Suture spanning augmentation of single-row rotator cuff repair: a biomechanical analysis

BACKGROUND

This in vitro study evaluated the biomechanical benefit of adding spanning sutures to single-row rotator cuff repair.

METHODS

Mechanical testing was performed to evaluate 9 pairs of cadaveric shoulders with complete rotator cuff repairs, with a single-row technique used on one side and the suture spanning technique on the other. The spanning technique included sutures from 2 lateral anchors securing tendon near the musculotendinous junction, spanning the same anchor placement from single-row repair. The supraspinatus muscle was loaded to 100 N at 0.25 Hz for 100 cycles, followed by a ramp to failure. Markers and a video tracking system measured anterior and posterior gap formation across the repair at 25-cycle intervals. The force at which the stiffness decreased by 50% and 75% was determined. Data were compared using paired t-tests.

RESULTS

One single-row repair failed at <25 cycles. Both anterior and posterior gap distances tended to be 1 to 2 mm larger for the single-row repairs than for the suture spanning technique. The difference was statistically significant at all cycles for the posterior gap formation (P ≤ .02). The trends were not significant for the anterior gap (P ≥ .13). The loads at which the stiffness decreased by 50% and 75% did not differ significantly between the 2 types of repair (P ≥ .10).

CONCLUSIONS

The suture spanning technique primarily improved posterior gap formation. Decreased posterior gap formation could reduce failure rates for rotator cuff repair.

[Patch augmentation of the rotator cuff. A reasonable choice or a waste of money?]

BACKGROUND

Although reconstruction methods have improved, tendon retears remain a major complication associated with rotator cuff repair. With the application of patches, either by interposition or by augmentation, surgeons can attempt to close an irreparable cuff defect or improve the mechanical and biological properties of tendons respectively.

OBJECTIVES

Which factors need to be considered when using a patch and what outcome can be expected?

MATERIALS AND METHODS

Based on the current literature, an overview of the techniques and materials in use and biomechanical and clinical experience is provided.

RESULTS

The literature shows clear improvements in the biomechanical properties of a repair with patch augmentation; in particular, weakened tendons of the anterior supraspinatus and superior infraspinatus benefit most. It is important to keep in mind that each patch material has its own individual properties, which makes comparison of the various patch types difficult. The current scientific evidence is promising, although larger level 1 studies are still required.

CONCLUSIONS

The general use of patches cannot be recommended at this time. Nevertheless, the use of a patch should be considered in patients who are at a high risk of recurrent retears. In future, patches will probably be applied mainly as part of a combined effort, together with biological measures to further reduce retear rates.

A prospective, multicenter study to evaluate clinical and radiographic outcomes in primary rotator cuff repair reinforced with a xenograft dermal matrix

BACKGROUND

Minimal information is currently available on the outcome of rotator cuff repair reinforced with an extracellular matrix (ECM) graft. Therefore, the purpose of this study was to determine the clinical and radiographic outcome of repair of large rotator cuff tears with ECM graft reinforcement.

METHODS

This was a prospective study of 61 shoulders with large repairable rotator cuff tears (3 to 5 cm). The rotator cuff tears were surgically repaired and reinforced with a xenograft ECM graft. The average patient age was 56 years (range, 40-69 years). The average tear size was 3.8 cm.

RESULTS

Follow-up was obtained at 6, 12, and 24 months in 58, 54, and 50 of the 61 patients, respectively. Functional outcome scores, isometric muscle strength, and active range of motion were significantly improved compared with baseline. Magnetic resonance imaging at 12 months showed retorn rotator cuff repairs in 33.9% of shoulders, using the criteria of a tear of at least 1 cm, and tears in 14.5% of the shoulders using the criteria of retear >80% of the original tear size. Three patients underwent surgical revision. Complications included 1 deep infection.

CONCLUSIONS

Repair of large rotator cuff tears structurally reinforced with xenograft ECM resulted in improved functional outcomes scores and strength. Adverse events were uncommon, and the rate of revision surgery was low.

Arthroscopic Rotator Cuff Repair With Graft Augmentation of Fascia Lata for Large and Massive Tears

Excellent clinical results of arthroscopic repair of rotator cuff tears have been reported. However, retears after surgical repair of large and massive rotator cuff tears are one of the most common complications. We present single-row repair with graft augmentation of the fascia lata for large and massive rotator cuff tears to reduce tension at the tendon-bone repair site, and this technique may prevent retears of the repaired rotator cuff. A candidate for this technique is a patient who has a large or massive rotator cuff tear in which the torn edge cannot reach the footprint after mobilization of the torn rotator cuff. This technique could provide an excellent option for irreparable large and massive rotator cuff tears.

Patch-Augmented Rotator Cuff Repair and Superior Capsule Reconstruction

Background:

Massive rotator cuff tears in active patients with minimal glenohumeral arthritis remain a particular challenge for the treating surgeon.

Methods:

A selective literature search was performed and personal surgical experiences are reported.

Results:

For patients with irreparable rotator cuff tears, a reverse shoulder arthroplasty or a tendon transfer are often performed. However, both procedures have rather high complication rates and debatable long-term results, particularly in younger patients. Therefore, patch-augmented rotator cuff repair or superior capsule reconstruction (SCR) have been recently developed as arthroscopically applicable treatment options, with promising biomechanical and early clinical results.

Conclusion:

For younger patients with irreparable rotator cuff tears wishing to avoid tendon transfers or reverse total shoulder arthroplasty, both patch-augmentation and SCR represent treatment options that may delay the need for more invasive surgery.

Augmented repair of radial meniscus tear with biomimetic electrospun scaffold: an in vitro mechanical analysis

Background

Large radial tears that disrupt the circumferential fibers of the meniscus are associated with reduced meniscal function and increased risk of joint degeneration. Electrospun fibrous scaffolds can mimic the topography and mechanics of fibrocartilaginous tissues and simultaneously serve as carriers of cells and growth factors, yet their incorporation into clinically relevant suture repair techniques for radial meniscus tears is unexplored. The purposes of this study were to (1) evaluate the effect of fiber orientation on the tensile properties and suture-retention strength of multilayered electrospun scaffolds and (2) determine the mechanical effects of scaffold inclusion within a surgical repair of a simulated radial meniscal tear. The experimental hypothesis was that augmentation with a multilayered scaffold would not compromise the strength of the repair.

Methods

Three multilayered electrospun scaffolds with different fiber orientations were fabricated–aligned, random, and biomimetic. The biomimetic scaffold was comprised of four layers in the following order (deep to superficial)–aligned longitudinal, aligned transverse, aligned longitudinal, and random–respectively corresponding to circumferential, radial, circumferential, and superficial collagen fibers of the native meniscus. Material properties (i.e., ultimate stress, modulus, etc.) of the scaffolds were determined in the parallel and perpendicular directions, as was suture retention strength. Complete radial tears of lateral bovine meniscus explants were repaired with a double horizontal mattress suture technique, with or without inclusion of the biomimetic scaffold sheath. Both repair groups, as well as native controls, were cyclically loaded between 5 and 20 N for 500 cycles and then loaded to failure. Clamp-to-clamp distance (i.e., residual elongation) was measured following various cycles. Ultimate load, ultimate elongation, and stiffness, were also determined. Group differences were evaluated by one-way ANOVA or Student’s t-test where appropriate.

Results

Aligned scaffolds possessed the most anisotropic mechanical properties, whereas random scaffolds showed uniform properties in the parallel and perpendicular directions. In comparison, the biomimetic scaffold possessed moduli in the parallel (68.7 ± 14.7 MPa) and perpendicular (39.4 ± 11.6 MPa) directions that respectively approximate the reported circumferential and radial tensile properties of native menisci. The ultimate suture retention load of the biomimetic scaffold in the parallel direction (7.2 ± 1.6 N) was significantly higher than all other conditions (p < 0.001). Biomimetic scaffold augmentation did not compromise mechanical properties when compared against suture repair in terms of residual elongation after 500 cycles (scaffold: 5.05 ± 0.89 mm vs. repair: 4.78 ± 1.24 mm), ultimate failure load (137.1 ± 31.0 N vs. 124.4 ± 21.4 N), ultimate elongation (12.09 ± 5.89 mm vs. 10.14 ± 4.61 mm), and stiffness (20.8 ± 3.6 vs. 18.4 ± 4.7 N/mm).

Conclusions

While multilayered scaffold sheets were successfully fabricated to mimic the ultrastructure and anisotropic tensile properties of native menisci, improvements in suture retention strength or adoption of superior surgical techniques will be needed to further enhance the mechanical strength of repairs of radial meniscal tears.

Massive rotator cuff tears: pathomechanics, current treatment options, and clinical outcomes

Rotator cuff tear size has an important effect on clinical outcomes after repair. Management options for massive rotator cuff tears are numerous, and selection of the most appropriate treatment method for individual patients can be a challenge. An understanding of the pathomechanics, treatment, and clinical outcomes in patients with massive rotator cuff tears can serve as a guide for clinical decision-making. The purpose of this article was to review treatment options and clinical outcomes for the management of massive rotator cuff tears.

Agreement among ASES members on the AAOS Clinical Practice Guidelines

The American Academy of Orthopaedic Surgeons (AAOS) has recently developed several clinical practice guidelines (CPG) involving upper extremity conditions. The purpose of the current study was to evaluate the practice patterns of members of the American Shoulder and Elbow Society (ASES) with regard to the CPGs. An e-mail survey was sent to the 340 members of the ASES. The survey contained 40 questions involving the subject matter of the 2 existing AAOS CPGs pertaining specifically to the shoulder: Optimizing the Management of Rotator Cuff Problems and the Treatment of Glenohumeral Joint Arthritis. Overall, 98 responses were obtained, for a response rate of 29%. Only 19 of 47 CPGs were not "inconclusive" and a recommendation was actually made. A majority (more than 50%) of surgeons agreed with 17 (90%) of 19 of these AAOS recommendations. A strong majority (more than 80%) adhered to 13 (68%) of 19 recommendations. There were 4 consensus recommendations, and more than 50% agreed with all of them. Of the 5 moderate recommendations, more than 50% agreed with 4 of them. There were 10 weak recommendations, and more than 50% of surgeons agreed with 9 of them. There was more than 80% agreement on 18 of 28 inconclusive recommendations. Although the AAOS CPGs are not meant to be fixed protocols, they are intended to unify treatment and/or diagnosis of common problems based on the best evidence available. Despite the majority of the AAOS CPG recommendations for rotator cuff problems and glenohumeral arthritis being inconclusive, most surgeons agree with most of the CPG recommendations.

Scaffolds for tendon and ligament repair and regeneration

Enhanced tendon and ligament repair would have a major impact on orthopedic surgery outcomes, resulting in reduced repair failures and repeat surgeries, more rapid return to function, and reduced health care costs. Scaffolds have been used for mechanical and biologic reinforcement of repair and regeneration with mixed results. This review summarizes efforts made using biologic and synthetic scaffolds using rotator cuff and ACL as examples of clinical applications, discusses recent advances that have shown promising clinical outcomes, and provides insight into future therapy.

Long-term successful arthroscopic repair of large and massive rotator cuff tears with a functional and degradable reinforcement device

BACKGROUND

Rotator cuff repair is a procedure with varying outcomes, and there has been subsequent interest in devices that reinforce the repair and enhance structural and functional outcomes. The objective of this study was to determine these outcomes for arthroscopic repair of large and massive rotator cuff tears augmented with a synthetic absorbable mesh designed specifically for reinforcement of tendon repair by imaging and clinical assessments.

MATERIALS AND METHODS

Consecutive arthroscopic repairs were performed on 18 patients with large to massive rotator cuff tears by use of a poly-l-lactic acid synthetic patch as a reinforcement device and fixation with 4 sutures. Patients were assessed preoperatively and at 6 months, 12 months, and a mean of 42 months after surgery by the American Shoulder and Elbow Surgeons (ASES) shoulder score to evaluate clinical performance and at 12 months by ultrasound to assess structural repair.

RESULTS

Ultrasound showed that 15 of 18 patients had intact rotator cuff repair at 12 months; at 42 months, an additional patient had a failed repair. Patients showed improvement in the ASES shoulder score from 25 preoperatively to 71 at 12 months and 70 at 42 months after surgery. Patients with intact rotator cuff (n = 14) at 42 months had an ASES shoulder score of 82.

DISCUSSION

The poly-l-lactic acid bioabsorbable patch designed specifically to reinforce the surgical repair of tendons supported successful repair of large to massive rotator cuff tears in 83% of patients at 12 months after surgery and 78% of patients at 42 months after surgery, with substantial functional improvement.

Time to failure after rotator cuff repair: a prospective imaging study

BACKGROUND

Failure of tendon healing after a rotator cuff repair is demonstrated by magnetic resonance imaging (MRI) as a fluid-filled defect within the tendon. The frequency of, and factors associated with, failure of the tendon repair to heal have been the focus of many clinical studies. The timing of when these defects occur has not been previously studied in a large prospectively defined patient population, to our knowledge. It was our hypothesis that the majority of failures occur within twelve weeks after surgery.

METHODS

One hundred and thirteen patients were enrolled in a multi-institutional prospective study. All patients had a standardized arthroscopic repair of a full-thickness tear of 1 to 4 cm as well as sequential MRI studies at six intervals from two weeks to fifty-two weeks. MRIs were reviewed at the time of imaging by the treating surgeon. Standardized patient-oriented clinical data were collected, physical examination was performed, and strength measurements were made preoperatively and postoperatively.

RESULTS

The treating surgeons diagnosed a recurrent tear with MRI in nineteen (17%) of the 113 patients within one year after surgery. The mean time to the retear was 19.2 weeks. There was a linear increase in retears over the first twenty-six weeks after surgery, and one additional tear was diagnosed between twenty-six and fifty-two weeks after repair.

CONCLUSIONS

Retears primarily occur between six and twenty-six weeks after arthroscopic rotator cuff repair, and few additional tears occur thereafter. A substantial number of retears occur between twelve and twenty-six weeks after repair.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.