Biomechanical and biologic augmentation for the treatment of massive rotator cuff tears

Comparison of Biological Augmentation in Rotator Cuff Repair Using Inflamed Versus Noninflamed Bursal Tissue in Rats

PURPOSE

To examine how augmentation of a rotator cuff repair with inflamed versus noninflamed bursal tissue affects tendon-to-bone healing in a rat model of rotator cuff repair.

METHODS

A total of 136 Sprague-Dawley rats were randomly assigned to an inflamed or noninflamed bursal tissue application group. After detachment, the supraspinatus tendon was reattached with bursal tissue sewn onto the tendon-to-bone interface. The specimens were analyzed biomechanically 6 and at 7 weeks and immunohistologically at 1 and at 7 weeks after surgery.

RESULTS

Immunohistological results showed no significant difference in the percentage of collagen type II in the tendon-to-bone interface at 1 (P = .87) and 7 weeks (P = .42) when using autologous noninflamed bursal tissue in comparison with inflamed bursal tissue specimens. The inflamed bursa group also showed no significant difference in collagen I to III quotient (P = .14) after surgery in comparison with noninflamed bursa groups after surgery. Biomechanical assessment showed that tendon stiffness (P = .87 inflamed versus noninflammed (resp.) P = .1) and the tendon viscoelasticity (P = .12 resp. P = .07) was the same after 6 and 7 weeks when we compared the inflamed bursa with the noninflamed bursa group. There was no significant difference (P = .8 resp. P = .87) in load to failure between in both inflamed and noninflamed bursa groups after 6 and 7 weeks.

CONCLUSIONS

Autologous inflamed bursal tissue derived from the Achilles bursa and implanted to the tendon-to-bone interface after rotator cuff repair facilitates the same histologic and biomechanical healing response as using a noninflamed bursa interposition in rats.

CLINICAL RELEVANCE

During augmentation of a rotator cuff repair, it is irrelevant whether the bursa tissue is inflamed.

Independent third row augmentation of massive rotator cuff repairs: surgical technique with radiological and patient outcomes

Background

Primary repair of massive posterosuperior rotator cuff is challenging with a high rate of failure. This study details the technique and outcomes of a standard double-row cuff repair augmented with a synthetic ligament inserted in a separate adjacent location from the tendon-bone construct to off-load and de-tension the repair interface.

Methods

Eleven patients with massive rotator cuff tears involving two or more tendons with >2.5 cm of retraction were prospectively enrolled. All patients underwent arthroscopically assisted mini-open double-row repair. This was augmented by a synthetic ligament passed medially through the supraspinatus and infraspinatus musculotendinous junctions before fixation distal to the second-row anchors. This represents a third row of repair that is remote from the double-row construct and aims to minimize repair tension. The primary outcome was repair integrity according to the Sugaya classification on postoperative magnetic resonance imaging. Secondary outcomes included the Constant score, EQ-5D 3L, and Oxford Shoulder Scores.

Results

The mean patient age was 65 with 10 males. At a mean follow-up of 13 months, 8 (73%) of the repaired tendons were intact on magnetic resonance imaging. Of the 3 retears, one occurred at the musculotendinous junction. All outcome scores were significantly improved after surgery beyond the minimal clinically important difference.

Conclusion

The insertion of an independent third row to off-load a standard rotator cuff repair construct resulted in favorable healing rates in patients with massive cuff tears. The technique is a simple, time-efficient method of de-tensioning the repair of massive rotator cuff tears.

Effect of abduction brace wearing angle on clinical outcomes after arthroscopic repair of large repairable rotator cuff: a retrospective study

BACKGROUND

Rotator cuff tears affect approximately 20% of the population and are usually repaired arthroscopically. The clinical outcomes of these repairs are influenced by multiple factors, including patient characteristics, surgical technique, and postoperative management. Postoperative shoulder posture, particularly the degree of abduction, plays an important role in repair site tension and tendon-bone healing. This study aimed to evaluate the clinical outcomes and repair integrity of patients undergoing arthroscopic repair of large rotator cuff tears using a 30° and 45° abduction brace.

METHODS

A total of 82 patients with symptomatic full-thickness rotator cuff tears were included in this study. The control group included 40 patients using a 30° brace, and the study group included 42 patients using a 45° abduction brace. Visual analogue scales (VAS) and humerohumeral range of motion were obtained before surgery and at 1 month (M1), 3 months (M3), and 6 months (M6) after surgery. Shoulder function scores (including Constant-Murley (CMS), University of California, Los Angeles (UCLA), and American Shoulder and Elbow Surgeons (ASES) scores) and retear rates were assessed at final follow-up (24 months).

RESULTS

Early passive ROM (flexion at 1 month, abduction at 1 and 3 months, external rotation at 1 and 3 months) was significantly better in the study group (45° abduction brace, P < 0.05). At 24 months, there were no significant differences in shoulder range of motion, function scores, and retear rates between the two groups (P > 0.05). Of note, in subgroup analysis, the retear rate was lower with a 45° brace than with a 30° brace under moderate to severe repair tension (16.67% vs. 44.44%, P < 0.05).

CONCLUSIONS

These results suggest that immobilization with a 45° brace rather than a 30° abduction brace after arthroscopic repair of large rotator cuff tears results in better passive range of motion during early follow-up, particularly with lower retear rates at moderate to severe repair strains.

Optimal suturing techniques in patch-bridging reconstruction for massive rotator cuff tears: A finite element analysis

Purpose

To use a finite element method to construct a patch-bridge repair model for massive rotator cuff tears (MRCTs) and investigate the effects of different suture methods and knot numbers on postoperative biomechanics.

Methods

A finite element model based on intact glenohumeral joint data was used for a biomechanical study. A full-thickness defect and retraction model of the supraspinatus tendon simulated MRCTs. Patch, suture, and anchor models were constructed, and the Marlow method was used to assign the material properties. Three suturing models were established: 1-knot simple, 1-knot mattress, and 2-knot mattress. The ultimate failure load, failure mode, stress distribution of each structure, and other biomechanical results of the different models were calculated and compared.

Results

The ultimate failure load of the 1-knot mattress suture (71.3 N) was 5.6 % greater than that of the 1-knot simple suture (67.5 N), while that (81.5 N) of the 2-knot mattress was 14.3 % greater than that of the 1-knot mattress. The stress distribution on the patch and supraspinatus tendon was concentrated on suture perforation. Failure of the bridging reconstruction mainly occurred at the suture perforation of the patch, and the damage forms included cutting-through and isthmus pull-out.

Conclusion

A finite element model for the patch-bridging reconstruction of MRCTs was established, and patch-bridging restored the mechanical integrity of the rotator cuff. The 2-knot mattress suture was optimal for patch-bridging reconstruction of MRCTs.

Double Row Rotator Cuff Repair for Massive Reparable Rotator Cuff Tear

Background

Massive rotator cuff tears, defined as those that involved 2 or more tendons or where the length of the greatest diameter is greater than 5 cm, present a unique surgical challenge as there can be significant scarring, retraction, and poor tissue quality. Furthermore, healing of these tears is less reliable. This video presents our technique for anatomic, double row repair of a massive reparable rotator cuff tear.

Indications

Indications for operative intervention include acute traumatic tears, as well as patients with pain and weakness who have failed to respond to conservative management, including physical therapy with confirmed large full thickness rotator cuff tear on advanced imaging. Of note, findings such as glenohumeral osteoarthritis, advanced muscle atrophy (Goutalier III/IV), superior migration of the humeral head >7 mm, and tears larger than 40 mm in length and width are concerning for irreparable tears, and may represent contraindications to surgical repair.

Technique Description

The patient is placed in the lateral decubitus position. After diagnostic arthroscopy is performed, a subacromial bursectomy is performed. A radiofrequency probe and arthroscopic shaver are used to perform releases in the subacromial space as well as superior to the glenoid. Preparation of the footprint of the humeral head is then performed to create a good healing surface. The rotator cuff is grasped to confirm tension free mobilization. The medial row anchors are then placed. Once placed, the sutures are incorporated into 2 lateral row anchors in sequential fashion. Subacromial decompression is then performed.

Results

Reduced pain and improved shoulder function are the goals of treatment, with sling immobilization lasting for roughly 6 weeks postoperatively prior to initiating strengthening and range of motion protocols.

Discussion/Conclusion

Arthroscopic double row repair produces an anatomic and stable reduction of reparable massive rotator cuff tears for patients that have failed conservative management.

Patient Consent Disclosure Statement

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Rotator Cuff Repair: The Compression SpeedBridge Technique

Background

While rotator cuff repair has generally produced good to excellent outcomes, re-tear rates remain variable, with rates ranging from 20% to 50%. The ideal rotator cuff repair includes 3 main components: restoration of the humeral footprint contact area, appropriate compression of the tendon to the humeral footprint, and minimal motion at the bone-tendon interface until bone-tendon healing is completed. This video takes a well-established knotless double-row technique for rotator cuff repair and augments it with a modification to promote additional compression of the medial row tendon to the humeral footprint.

Indications

This compression SpeedBridge technique is indicated for repair of T-type rotator cuff tears involving the supraspinatus and infraspinatus tendons in patients that have failed conservative management, including physical therapy, activity modification, and corticosteroid injections. This technique can also be applied to U-shaped or L-shaped tears by removing the initial step, which involves side-to-side repair of the "T" portion of the T-type tear. Of note, findings such as advanced muscle atrophy (Goutalier III/IV) and advanced glenohumeral arthritis are concerning for irreparable tears and may be contraindications for surgical repair.

Technique Description

With the patient in the lateral decubitus position, a diagnostic arthroscopy is performed, the rotator cuff tear is debrided, and the footprint prepared. Two side-to-side stitches are placed to repair the "T" portion of the tear. The medial row anchors are then sequentially placed, and the pre-loaded sutures are passed through the tendon in 4 sequential locations in specific fashion. After placement of looped sutures in the anterior and posterior rotator cables, the passed sutures are then incorporated into the lateral row anchors. The medial row compression is provided by shuttling previously placed compression stitches through the knotless mechanism in the medial row anchors and terminally tensioned.

Results

This technique provides additional medial row compression to an already-established knotless double-row rotator cuff repair technique to facilitate improved bone-tendon healing and construct strength.

Discussion/Conclusion

The compression SpeedBridge technique is a unique method to apply additional medial row compression to a double-row rotator cuff repair.

Patient Consent Disclosure Statement

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Transosseous-Equivalent/Suture Bridge Technique in Combination With Platelet-Rich Plasma Application Yield Optimal Clinical Outcomes in Arthroscopic Rotator Cuff Repair: A Bayesian Network Analysis of Randomized Controlled Trials

PURPOSE

To assess the clinical evidence defining the optimal combination of arthroscopic suture technique and platelet-rich products (PRP), and application for arthroscopic rotator cuff repair (ARCR).

METHODS

All level of evidence (LOE) I randomized controlled trials (RCT) focusing on arthroscopic suture technique and/or PRP application in ARCR were included. The exclusion criteria were LOE II or worse, studies with other interventions, studies reported none of the predetermined clinical outcomes; studies unable to extract any precise data; studies from the same patient group of included studies. A pair-wise meta-analysis and Bayesian network analysis were performed on each comparison. The intervention options were ranked by Bayesian network analysis.

RESULTS

27 studies comprising 1,947 individuals met the inclusion criteria. The application of transosseous equivalent/suture bridge repair (SB) with PRP (SB+PRP) significantly reduced retear rate (risk ratio [RR], 0.29; 95% confidence interval [CI], [0.15, 0.55].) and increased Constant-Murley score (mean difference, 1.90; 95% CI, [0.14, 3.74]), compared to SB repair. Single-row repair (SR) with PRP usage (SR+PRP) significantly reduced retear rate (RR, 0.27; 95% CI, [0.12, 0.55]) and pain visual analog scale (VAS) (mean difference: -0.84; 95% CI [-1.39, -0.46].), increased University of California, Los Angeles (UCLA) shoulder score (mean difference: 1.48; 95% CI [0.50, 2.58]) and Constant-Murley score (mean difference: 4.53; 95% CI [2.65, 6.38]), compared to SR repair. The ranking for outcomes demonstrated SB+PRP resulted in the best retear rate, UCLA shoulder score, with the second-best postoperative pain, Constant-Murley score, while SR+PRP resulted in the best postoperative pain, Constant-Murley score, with the second-best retear rate and UCLA score.

CONCLUSION

Arthroscopic rotator cuff repair utilizing SB+PRP yields optimal retear rate and UCLA shoulder score, with the second-best postoperative pain and Constant-Murley shoulder outcome score, while SR+PRP yields the best in these two parameters.

LEVEL OF EVIDENCE

Level I, Bayesian network analysis of level I RCT.

Clinical Outcomes After Arthroscopic Rotator Cuff Repair With a Fibrin Scaffold Containing Growth Factors and Autologous Progenitor Cells Derived from cBMA

Purpose

To report the clinical outcomes after biologically augmented rotator cuff repair (RCR) with a fibrin scaffold derived from autologous whole blood and supplemented with concentrated bone marrow aspirate (cBMA) harvested at the proximal humerus.

Methods

Patients who underwent arthroscopic RCR with biologic augmentation using a fibrin clot scaffold (“Mega- Clot”) containing progenitor cells and growth factors from proximal humerus BMA and autologous whole blood between April 2015 and January 2018 were prospectively followed. Only high-risk patients in primary and revision cases that possessed relevant comorbidities or physically demanding occupation were included. Minimum follow-up for inclusion was 1 year. The visual analog score for pain (VAS), American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), Single Assessment Numerical Evaluation (SANE), and Constant-Murley scores were collected preoperatively and at final follow-up. In vitro analyses of the cBMA and fibrin clot using nucleated cell count, colony forming units, and live/dead assays were used to quantify the substrates.

Results

Thirteen patients (56.9 ± 7.7 years) were included. The mean follow-up was 26.9 ± 17.7 months (n = 13). There were significant improvements in all outcome scores from the preoperative to the postoperative state: VAS (5.6 ± 2.5 to 3.1 ± 3.2; P < .001), ASES (42.0 ± 17.1 to 65.5 ± 30.6; P < .001), SST (3.2 ± 2.8 to 6.5 ± 4.7; P = .002), SANE (11.5 ± 15.6 to 50.3 ± 36.5; P < .001), and Constant-Murley (38.9 ± 17.5 to 58.1 ± 26.3; P < .001). Six patients (46%) had retears on postoperative MRI, despite all having improvements in pain and function except one. All failures were chronic rotator cuff tears, and all were revision cases except one (1.6 ± 0.5 previous RCRs). The representative sample of harvested cBMA showed an average of 28.5 ± 9.1 × 10⁶ nucleated cells per mL.

Conclusions

Arthroscopic rotator cuff repairs that are biologically augmented with a fibrin scaffold containing growth factors and autologous progenitor cells derived from autologous whole blood and humeral cBMA can improve clinical outcomes in primary, as well as revision cases in high-risk patients. However, the incidence of retears remains a concern in this population, demanding further improvements in biologic augmentation.

Level of Evidence

IV, therapeutic case series.

Biomechanical and Histological Results of Dual-Suspensory Reconstruction Using Banded Tendon Graft to Bridge Massive Rotator Cuff Tears in a Chronic Rabbit Model

BACKGROUND

Bridging rotator cuff tendon defects with a patch is a reasonable treatment for massive rotator cuff tears (MRCTs). However, the poor outcomes associated with routine patch repair have prompted exploration into superior bridging techniques and graft structures.

PURPOSE

To detect whether dual-suspensory reconstruction using a banded graft would be superior to routine bridging using a patch graft to treat MRCTs and to detect the comparative effectiveness of patellar tendon (PT) and fascia lata (FL) grafts in dual-suspensory reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral chronic MRCTs were created in 72 mature male New Zealand White rabbits, which were randomly divided into 3 groups: (1) patch bridging repair using rectangular FL autograft (PR-FL), (2) dual-suspensory bridging reconstruction using banded FL autograft (DSR-FL), and (3) dual-suspensory bridging reconstruction using banded PT autograft (DSR-PT). In each group, the mean failure load and stiffness of the cuff-graft-humerus (C-G-H) complexes of 6-week and 12-week specimens were recorded, with the failure modes and sites noted. Moreover, cuff-to-graft and graft-to-bone interface healing and graft substance remodeling of the complexes were histologically evaluated (via hematoxylin and eosin, Picrosirius red, Masson trichrome, and Safranin O/fast green staining) at 6 and 12 weeks to assess integrations between the bridging constructs and the native bone or rotator cuff tendons.

RESULTS

The DSR-PT group had the greatest mean failure loads and stiffness of the C-G-H complexes at 6 and 12 weeks (41.81 ± 7.00 N, 10.34 ± 2.68 N/mm; 87.62 ± 9.20 N, 17.98 ± 1.57 N/mm, respectively), followed by the DSR-FL group (32.04 ± 5.49 N, 8.20 ± 2.27 N/mm; 75.30 ± 7.31 N, 14.39 ± 3.29 N/mm, respectively). In the DSR-PT and DSR-FL groups, fewer specimens failed at the graft-to-bone junction and more failed at the cuff-to-graft junction, but both groups had higher median failure loads at 6 and 12 weeks (DSR-PT: cuff-to-graft junction, 37.80 and 83.76 N; graft-to-bone junction, 45.46 and 95.86 N) (DSR-FL: cuff-to-graft junction, 28.52 and 67.68 N; graft-to-bone junction, 37.92 and 82.18 N) compared with PR-FL (cuff-to-graft junction, 27.17 and 60.04 N; graft-to-bone junction, 30.12 and 55.95 N). At 12 weeks, the DSR-FL group had higher median failure loads at graft substance (72.26 N) than the PR-FL group (61.27 N). Moreover, the PR-FL group showed more inflammatory responses at the 2 healing interfaces and the graft substance in the 6-week specimens and subsequently displayed poorer interface healing (assessed via collagen organization, collagen maturity, and fibrocartilage regeneration) and graft substance remodeling (assessed via collagen organization and maturity) in 12-week specimens compared with the DSR-PT and DSR-FL groups. Superior interface healing and substance remodeling processes were observed in the DSR-PT group compared with the DSR-FL group.

CONCLUSION

When compared with routine patch repair, the dual-suspensory reconstructions optimized biomechanical properties and improved interface healing and graft substance remodeling for bridging MRCTs. Furthermore, the dual-suspensory technique using the PT graft presented superior histological and biomechanical characteristics than that using FL.

CLINICAL RELEVANCE

The dual-suspensory reconstruction technique using banded tendon grafts may enhance bridging constructs for MRCTs in humans, warranting further investigations of clinical outcomes.

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

Background

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

Methods

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

Results

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

Conclusion

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

Histologic and biomechanical evaluation of the thoracolumbar fascia graft for massive rotator cuff tears in a rat model

BACKGROUND

Fascial autografts, which are easily available grafts, have provided a promising option in patients with massive rotator cuff tears. However, no fascial autografts other than the fascia lata have been reported, and the exact healing process of the fascia-to-bone interface is not well understood. The objective of this study is to histologically and biomechanically evaluate the effect of the thoracolumbar fascia (TLF) on fascia-to-bone healing.

METHODS

A total of 88 rats were used in this study. Eight rats were killed at the beginning to form an intact control group, and the other rats were divided randomly into 2 groups (40 rats per group): the TLF augmentation group (TLF group) and the repair group (R group). The right supraspinatus was detached, and a 3 × 5 mm defect of the supraspinatus was created. The TLF was used to augment the torn supraspinatus in the TLF group, whereas in the R group, the torn supraspinatus was repaired in only a transosseous manner. Histology and biomechanics were assessed at 1, 2, 4, 8, and 16 weeks postoperatively.

RESULTS

The modified tendon maturation score of the TLF group was higher than that of the R group at 8 weeks (23.00 ± 0.71 vs. 24.40 ± 0.89, P = .025) and 16 weeks (24.60 ± 0.55 vs. 26.40 ± 0.55, P ≤ .001). The TLF group showed a rapid vascular reaction, and the peak value appeared at 1 week. Later, the capillary density decreased, and almost no angiogenesis was observed at 8 weeks postoperatively. Immunohistochemistry results demonstrated a significantly higher percentage of collagen I in the TLF group at 4, 8, and 16 weeks (24.78% ± 2.76% vs. 20.67% ± 2.11% at 4 weeks, P = .046; 25.46% ± 1.77% vs. 21.49% ± 2.33% at 8 weeks, P = .026; 34.77% ± 2.25% vs. 30.01% ± 3.17% at 16 weeks, P = .040) postoperatively. Biomechanical tests revealed that the ultimate failure force in the TLF group was significantly higher than that in the R group at the final evaluation (29.13 ± 2.49 N vs. 23.10 ± 3.47 N, P = .022).

CONCLUSIONS

The TLF autograft can promote a faster biological healing process and a better fixation strength. It could be used as an alternative reinforcement or bridging patch when the fascia lata is not appropriate or available for superior capsule reconstruction (SCR).

Full-Thickness Massive Rotator Cuff Repair With a Dermal Allograft Using CuffMend Augmentation Technique

Background

Rotator cuff repair using graft augmentation for large-to-massive, full-thickness rotator cuff tears has been reported to have improved clinical outcomes relative to other therapeutic interventions. Although an effective and promising technique, graft augmentation can be technically challenging, particularly with deployment and positioning of the graft. CuffMend is a user-friendly rotator cuff augmentation technique that combines a decellularized dermal allograft with a novel graft deployment device, tendon anchor, and set of lateral knotless, tension-able anchors to allow for a reliable and stable implantation of the graft.

Indications

Graft augmentation using CuffMend is indicated for tears with a high risk of retear or incomplete healing. This includes revision tears, poor-quality degenerative tissue, and massive full-thickness rotator cuff tears. Severe glenohumeral osteoarthritic change is the primary contraindication to this technique.

Technique Description

The rotator cuff is reduced medially and secured using 3 anchors with sutures passed in a mattress configuration. Graft augmentation is then performed using the CuffMend graft spreader that facilitates placement and attachment of the graft onto the repaired tendon.

Results

The patient is recovering as expected and started physical therapy 1 month postoperatively. He is able to perform light activities of daily living and reach the top of his head for daily self-care without pain. He will begin strengthening at 12 weeks postoperatively.

Discussion/Conclusion

CuffMend is a new graft augmentation technique that uses a novel graft deployment device for consistent and precise deployment of a decellularized dermal allograft. This facilitates an expedited repair using the graft augmentation technique for optimal clinical and biomechanical outcomes in patients with rotator cuff tears with high risk of retear.

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.

Biceps Augmentation Outperforms Tear Completion Repair or In Situ Repair for Bursal-Sided Partial-Thickness Rotator Cuff Tears in a Rabbit Model

BACKGROUND

There is an ongoing debate on the treatment of bursal-sided partial-thickness rotator cuff tears (PTRCTs), including ideal repair techniques. Augmentation using a collagen patch has been introduced as a new surgical approach to treat PTRCTs, while the effect of autogenous biceps augmentation (BA) has not been investigated.

PURPOSE

To analyze the effects of BA on bursal-sided PTRCTs and compare its histological and biomechanical results with those of tear completion followed by repair and in situ repair (ISR).

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral chronic PTRCTs were created in 96 mature New Zealand White rabbits, which were randomly divided into 4 groups: no repair, tear completion repair (TCR), ISR, and BA. A new bicipital groove was fabricated in BA for the biceps tendon that was transferred to augment the bursal-sided PTRCT repair. In each group, we sacrificed 6 rabbits for biomechanical testing of the whole tendon-to-bone complex (WTBC) and 6 for histological evaluation of bursal- and articular-sided layers at 6 and 12 weeks postoperatively. Healing responses between the biceps and new bicipital groove in the BA group were determined using histological analysis, and final groove morphologies were evaluated using micro-computed tomography.

RESULTS

The remaining tendon and enthesis in bursal-sided PTRCTs progressively degenerated over time. WTBCs of ISR exhibited a larger failure load than those of TCR, although better healing properties in the bursal-sided repaired site were achieved using TCR based on histological scores and superior articular-sided histological scores were observed using ISR. However, WTBCs of BA displayed the best biomechanical results and superior histological scores for bursal- and articular-sided regions. The new bicipital groove in BA remodeled over time and formed similar morphologies to a native groove, which provided a mature bone bed for transferred biceps tendon healing to augment bursal-sided PTRCTs.

CONCLUSION

BA achieved better biomechanical and histological results for repairing bursal-sided PTRCTs as compared with TCR and ISR. When compared with that of TCR, the WTBC of ISR exhibited a higher failure load, showing histological superiority in the articular-sided repair and inferiority in the bursal-sided repair.

CLINICAL RELEVANCE

BA may be an approach to improve bursal-sided PTRCT repair in humans, which warrants further clinical investigation.

Arthroscopic rotator cuff repair with biologically enhanced patch augmentation

OBJECTIVE

The purpose of this guide is to illustrate an arthroscopic rotator cuff repair (RCR) with two techniques for biologically enhanced patch augmentation.

INDICATIONS

Massive rotator cuff tears (> 5 cm) and revision RCR.

CONTRAINDICATIONS

Active joint or systemic infection; severe fatty muscle atrophy; severe glenohumeral arthropathy; American Society of Anesthesiologists Physical Status (ASA PS) IV.

SURGICAL TECHNIQUE

Dermal allograft patch augmented with concentrated bone marrow aspirate (cBMA), platelet-rich plasma (PRP) and platelet-poor plasma (PPP); or Regeneten patch augmented with bursa, PRP, PPP, and autologous thrombin.

POSTOPERATIVE MANAGEMENT

A 30° abduction sling for 6 weeks; unrestricted active-assisted external rotation and forward elevation after 12 weeks; focus on restoration of scapular stability and strength.

RESULTS

A total of 22 patients received revision massive RCR using a dermal allograft patch enhanced with cBMA and PRP with a mean follow-up of 2.5 years (1.0-5.8 years). There was a significant improvement in the preoperative Simple Shoulder Test (SST). There was also a trend towards improved pain and American Shoulder and Elbow Surgeons (ASES) Shoulder Score. In this cohort, 45% reached the minimal clinically important difference (MCID), 41% achieved substantial clinical benefit (SCB), and 32% had a patient-acceptable symptomatic state (PASS) for the ASES score. Preliminary data using the Regeneten patch technique with bursa, PRP, PPP, and autologous thrombin was prospectively collected in five patients between 05/2020 and 03/2021 at the author's institution. Mean follow-up was 6.5 ± 1.3 (6-8 months). There was an improvement from preop to postop in pain, ASES, SANE, Constant-Murley (CM) score and active range of motion.

Histologic Analysis of Porcine Dermal Graft Augmentation in Treatment of Rotator Cuff Tears

BACKGROUND

Biologic augmentation via extracellular matrix (ECM) scaffolds has been utilized to address rotator cuff tears with poor-quality tissue.

PURPOSE

To evaluate the cellular changes in graft explants taken from patients treated with porcine dermal grafts for rotator cuff tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Four graft biopsy specimens were obtained from patients treated with porcine dermal grafts in an interposition technique for rotator cuff tears and compared with a nonimplanted graft and a normal rotator cuff specimen. Biopsy of the graft site was performed at 18 days, 3 months, 7 months, and 10.5 months after implantation. Hematoxylin and eosin staining was used to evaluate for cellular and vascular changes. Picrosirius red (PSR) stain with 90° polarized light was performed to evaluate collagen fibril size and orientation. All biopsy specimens were analyzed by a pathologist.

RESULTS

There was evidence of progressive remodeling of the porcine dermal grafts. The most mature grafts demonstrated vessel infiltration and extensive remodeling without evidence of inflammation, foreign body reaction, or tissue rejection. PSR demonstrated increased organization of collagen domains, resembling normal tendon by 10.5 months postoperatively.

CONCLUSION

This series suggests that ECM grafts may serve as an effective scaffold for host cell infiltration, collagen reorganization, and vascularization as a result of histologic changes demonstrated with retrieval of specimens from patients with rotator cuff tears that were augmented with porcine dermal grafts.

Efficacy of Intraoperative Platelet-Rich Plasma Augmentation and Postoperative Platelet-Rich Plasma Booster Injection for Rotator Cuff Healing: A Randomized Controlled Clinical Trial

Background:

Platelet-rich plasma (PRP) has been applied as an adjuvant treatment for arthroscopic rotator cuff repair (ARCR) to enhance rotator cuff healing. However, it remains debatable whether PRP enhances tendon-to-bone healing.

Purpose:

To assess the efficacy of intraoperative augmentation and postoperative injection of PRP that was prepared using the double-spin method and calcium activation without thrombin in patients with ARCR.

Study Design:

Randomized controlled trial; Level of evidence, 1; and cohort study; Level of evidence, 3.

Methods:

A total of 58 patients underwent ARCR using intraoperative PRP augmentation. Half of the patients were randomly assigned to receive an additional ultrasound-guided PRP injection at the repair site at 2 weeks postoperatively (PRP-booster group); the other half did not receive the booster injection (PRP-only group). A control group that did not receive any PRP treatment was retrospectively matched using propensity score matching. Structural integrity was assessed using magnetic resonance imaging at 1 year postoperatively, and healing rates were compared between patients with tear sizes ≤2 cm versus >2 cm. Functional outcomes were assessed using the visual analog scale (VAS) for pain; VAS for satisfaction; shoulder range of motion; and Constant, American Shoulder and Elbow Surgeons, and Simple Shoulder Test scores at minimum 2-year follow-up.

Results:

In patients with tears >2 cm, the rate of healing failure at 1-year follow-up was significantly less in the overall PRP group than in the control group (12.9% vs 35.7%, respectively; P = .040), however, the PRP-booster group did not present a better healing rate than did the PRP-only group. The overall PRP group had lower VAS for pain scores compared with the control group (0.5 ± 1.1 vs 1.3 ± 1.8, respectively; P = .016) and higher VAS for satisfaction scores (9.2 ± 1.2 vs 8.6 ± 1.7; P = .023) at the final follow-up, whereas no statistical difference was found between the PRP-only and PRP-booster groups in functional outcomes.

Conclusion:

Intraoperative PRP augmentation during ARCR demonstrated superior anatomic healing results in patients with rotator cuff tears >2 cm as well as reduced pain and increased subjective satisfaction. PRP booster injection provided no additional benefit to tendon integrity or functional recovery.

The Effect of Insulin and Insulin-like Growth Factor 1 (IGF-1) on Cellular Proliferation and Migration of Human Subacromial Bursa Tissue

Purpose

To evaluate the effect of a one-time dose of insulin or insulin-like growth factor 1 (IGF-1) on cellular proliferation and migration of subacromial bursa tissue (SBT) over time.

Methods

SBT was harvested from over the rotator cuff tendon in 4 consecutive patients undergoing primary arthroscopic rotator cuff repair. SBT was cultured for 3 weeks in complete media until reaching confluence. The culture dishes were stored in a humidified, low oxygen tension (5% CO₂) incubator at 37°C. SBT of each patient underwent treatment with a one-time dose of insulin or IGF-1, whereas nontreated SBT served as a negative control. Cellular proliferation and migration were evaluated after 24, 48, 72, and 96 hours of incubation. SBT-derived cells migrated in the detection field were visualized using fluorescent microscopy.

Results

Cellular proliferation at 24, 48, 72, and 96 hours was 1.40 ± 0.27, 1.00 ± 0.20, 1.47 ± 0.31, and 1.68 ± 0.28 for IGF-1; 1.44 ± 0.24, 1.15 ± 0.27, 1.60 ± 0.36, and 1.61 ± 0.32 for insulin; and 1.51 ± 0.35, 1.29 ± 0.33, 1.53 ± 0.35, and 1.57 ± 0.38 for nontreated SBT. Untreated SBT demonstrated a significantly greater proliferation when compared with IGF-1 and insulin within the first 48 hours, although this effect was found to subside by 96 hours. Cellular migration at 24, 48, 72, and 96 hours was 575.7 ± 45.0, 641.6 ± 77.7, 728.3 ± 122.9, and 752.3 ± 114.5 for IGF-1; 528.4 ± 31.3, 592.5 ± 69.8, 664.2 ± 115.2, and 695.6 ± 148.2 for insulin; and 524.4 ± 41.9, 564.4 ± 49.8, 653.2 ± 81.5, and 685.7 ± 115.5 for nontreated SBT. Insulin showed no difference in migration at each timepoint compared to nontreated SBT (P > .05, respectively).

Conclusions

Insulin and IGF-1 initially inhibit cellular proliferation of human SBT, although this effect was found to subside by 96 hours. Further, neither insulin nor IGF-1 changed the slope of cellular migration over time. However, each treatment group demonstrated a significant increase in cellular proliferation and migration.

Clinical Relevance

In the setting of biologic augmentation of rotator cuff repair, the compatibility and synergistic effect of insulin on human SBT is highly limited.

Subacromial Bursa-Derived Cells Demonstrate High Proliferation Potential Regardless of Patient Demographics and Rotator Cuff Tear Characteristics

PURPOSE

To investigate the influence of patient demographics and rotator cuff tear characteristics on the cellular proliferation potential of subacromial bursa-derived cells (SBDCs).

METHODS

Patients undergoing arthroscopic rotator cuff repair between December 2017 and February 2019 were considered for enrollment in the study. Basic demographic information as well as medical and surgical history were obtained for each patient. Subacromial bursa was harvested from over the rotator cuff tendon. Cellular proliferation was evaluated after 3 weeks of incubation by counting nucleated SBDCs. Fluorescence-activated cell sorting (FACS) analysis was performed to confirm the presence of mesenchymal stem cell (MSC) specific surface markers. Using preoperative radiographs and magnetic resonance imaging (MRI), acromiohumeral distance (AHD), severity of cuff tear arthropathy, and rotator cuff tear characteristics were evaluated.

RESULTS

Seventy-three patients (mean age: 57.2 ± 8.5 years) were included in the study. There was no significant difference in cellular proliferation of SBDCs when evaluating the influence of age, sex, body mass index (BMI), smoking status, and presence of systemic comorbidities (p > .05, respectively). Similarly, there was no significant difference in cellular proliferation of SBDCs when looking at rotator cuff tear characteristics (size, tendon retraction, fatty infiltration, muscle atrophy), AHD, or severity of cuff tear arthropathy (p > .05). FACS analysis confirmed nucleated SBDCs to have a high positive rate of MSC specific surface markers.

CONCLUSION

Subacromial bursa consistently demonstrated a high cellular proliferation potential regardless of patient demographics, rotator cuff tear characteristics, and severity of glenohumeral joint degeneration.

CLINICAL RELEVANCE

These findings may alleviate concerns that subacromial bursa might lose cellular proliferation potential when being used for biologic augmentation in massive and degenerated rotator cuff tears, thus assisting in predicting tendon healing and facilitating surgical decision-making.

Preliminary Clinical Outcomes Following Biologic Augmentation of Arthroscopic Rotator Cuff Repair Using Subacromial Bursa, Concentrated Bone Marrow Aspirate, and Platelet-Rich Plasma

Purpose

To evaluate the clinical outcomes of patients who underwent arthroscopic rotator cuff repair augmented using subacromial bursa, concentrated bone marrow aspirate (cBMA), and platelet-rich plasma.

Methods

Sixteen patients were included in the study who underwent arthroscopic rotator cuff repair augmented using subacromial bursa, cBMA, and platelet-rich plasma from January 2018 to July 2018 and had a minimum 1-year follow-up. American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test, Constant-Murley, and Single Assessment Numerical Evaluation (SANE) scores were collected preoperatively and at terminal follow-up. To determine the clinical relevance of ASES scores, the minimal clinically important difference, substantial clinical benefit, and the patient acceptable symptomatic state thresholds were used. In vitro cellular proliferation of subacromial bursa (nucleated cells/gram) and cBMA (nucleated cells and colony-forming units/cc) samples was evaluated and correlated to clinical outcomes scores.

Results

Mean follow-up was 12.6 ± 1.8 months (range 12-19 months). Patients achieved significant improvement in ASES (45.8±22.5_pre vs 88.5 ± 14.6_post, Δ44.7 ± 20.7; P = .001), Simple Shoulder Test (4.3 ± 3.2_pre vs 10.4 ± 1.6_post, Δ5.7 ± 3.9, P = .002), Constant-Murley (44.3 ± 18.2_pre vs 83.6 ± 17.5_post, Δ37.2 ± 21.8; P = .001), SANE (13.3 ± 10.7_pre vs 86.3 ± 17.5_post, Δ71.9 ± 22.9; P = .001), and pain scores (5.0±2.8_pre vs 1.1 ± 1.6_post, Δ3.5±2.5, P = .001) at final follow-up. With regards to ASES score, 93.8% of patients achieved the minimal clinically important difference, 93.8% the substantial clinical benefit, and 62.5% reached or exceeded the patient acceptable symptomatic state criteria. There was a significant positive correlation of nucleated cell count of cBMA with postoperative SANE score (r = 0.707; P = .015) and delta in ASES score (r = 0.727; P = .011). All other correlations were found to be nonsignificant (P > .05, respectively).

Conclusions

Patients undergoing arthroscopic rotator cuff repair augmented using the Mega-Clot with bursa technique achieved significant improvement in functional outcomes at a minimum 1-year follow-up, with 93.8% of patients reaching substantial clinical benefit.

Level of Evidence

Level IV, therapeutic case series.

The effect of autologous Achilles bursal tissue implants in tendon-to-bone healing of rotator cuff tears in rats

BACKGROUND

The aim of this study was to investigate the influence of autologous bursal tissue derived from the Achilles bursa on tendon-to-bone healing after rotator cuff tear repair in a rat model.

METHODS

A total of 136 Sprague-Dawley rats were randomly assigned to either an untreated or a bursal tissue application group or biomechanical testing and histologic testing after rotator cuff repair. After separating the supraspinatus tendon close to the greater tuberosity, the tendon was reattached either unaltered or with a bursal tissue interposition sewn onto the interface. Immunohistologic analysis was performed 1 and 7 weeks after supraspinatus tendon reinsertion. Biomechanical testing of the tendon occurred 6 and 7 weeks after reinsertion.

RESULTS

Immunohistologic results demonstrated a significantly higher percentage of Type II collagen (P = .04) after 1 and 7 weeks in the tendon-to-bone interface using autologous bursal tissue in comparison to control specimens. The bursa group showed a significantly higher collagen I to III quotient (P = .03) at 1 week after surgery in comparison to the 7-week postsurgery bursa groups and controls. Biomechanical assessment showed that overall tendon stiffness (P = .002) and the tendon viscoelasticity in the bursa group (P = .003) was significantly improved after 6 and 7 weeks. There was no significant difference (P = .55) in force to failure between the bursa group and the control group after 6 and 7 weeks.

CONCLUSION

Autologous bursal tissue derived from the Achilles bursa and implanted to the tendon-to-bone interface after rotator cuff repair facilitates a faster healing response to re-establish the biologic and biomechanical integrity of the rotator cuff in rats.

Arthroscopic superior capsular reconstruction versus latissimus dorsi transfer for irreparable rotator cuff lesions: a systematic review

INTRODUCTION

The present systematic review compared arthroscopic superior capsular reconstruction (ASCR) and latissimus dorsi transfer (ALDT) for the management of massive irreparable rotator cuff lesions.

SOURCES OF DATA

We performed a systematic review searching the literature on Medline, Cochrane and Scopus databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

AREAS OF AGREEMENT

We included a total of 20 articles, 10 on ASCR and 10 on ALDT (12 retrospective and 8 prospective studies), all published between 2013 and 2019.

AREAS OF CONTROVERSY

ASCR and ALDT are technical demanding procedures. When compared to each other, they do not produce significantly different improvements in clinical outcome.

GROWING POINTS

Both ASCR and ALDT are valid options for surgical management of MIRCLs. Although ALDT has shown a greater complication rate and a less improvement in acromion-humeral distance, its clinical outcomes overlap those obtained with ASCR.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further comparative prospective and retrospective studies with longer follow-up could confirm which surgical procedure can lead to better outcomes with a lower complication rate.

Clinical Outcomes Following Biologically Enhanced Patch Augmentation Repair as a Salvage Procedure for Revision Massive Rotator Cuff Tears

PURPOSE

To evaluate the clinical outcomes of patients who underwent biologically enhanced patch augmentation repair for the treatment of revision massive rotator cuff tears.

METHODS

Twenty-two patients who underwent arthroscopic and mini-open rotator cuff repair using a patch augmented with platelet-rich plasma and concentrated bone marrow aspirate (cBMA) for revision massive (≥2 tendons) rotator cuff tears from 2009 to 2014, with a minimum 1-year follow-up, were included in the study. In this procedure the medial side of the graft is secured to the rotator cuff tendon remaining medially. American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test, and postoperative Single Assessment Numerical Evaluation scores were evaluated. To determine the clinical relevance of ASES scores, the minimal clinically important difference, substantial clinical benefit (SCB), and the patient-acceptable symptomatic state (PASS) thresholds were used. Clinical success or failure was defined based on whether the patient reached the SCB threshold. In the laboratory, cellular counting along with the concentration of connective tissue progenitor cells were performed on patch samples from the day of surgery. Scaffolds were processed histologically at days 0, 7,14, and 21 of culture.

RESULTS

Patients had significant improvement in the Simple Shoulder Test (2.6 ± 3.0_pre vs 5.2 ± 4.2_post, P = .01), whereas improvement in pain scores was found to be nonsignificant (5.6 ± 2.5_pre vs 4.2 ± 3.4_post,P = .11) at final follow-up. Mean ASES improved by Δ14.6 ± 33.4 points; however, this did not reach statistical significance (40.2 ± 21.6_pre vs 53.9 ± 31.4_post,P = .10). With regards to ASES score, 45% of patients achieved the minimal clinically important difference, 41% the SCB, and 32% reached or exceeded the PASS criteria. At 21 days, there was a significantly greater cell count in scaffolds from patients who had clinical success than those who were failures (P = .02).

CONCLUSIONS

Only 41% of patients undergoing biologically enhanced patch augmentation repair reached substantial clinical benefit, whereas 32% reached or exceeded the PASS criteria.

LEVEL OF EVIDENCE

Case Series: Level IV.

Macroporous 3D Scaffold with Self-Fitting Capability for Effectively Repairing Massive Rotator Cuff Tear

The postoperative retear rate of direct repair of massive rotator cuff tear has risen up to 40% because of the dissatisfied tendon-to-bone healing and poor regenerative potential of remnant rotator cuff tissue. A biological scaffold that connects the remnant rotator cuff tissue and bone might be a promising substitute. In the present study, we have developed a macroporous three-dimensional scaffold poly(ester-urethane)urea (PEUU), with self-fitting capability employing thermally induced phase separation (TIPS) technique. The scaffold provides oriented connected macropores for cells migration, and promoted tendon-to-bone healing on the basis of surgical repair. The scaffolds were characterized by scanning electron microscopy, stress-strain test and cell biocompatibility study. In vitro studies exhibited that PEUU scaffold with suitable elastic mechanical properties can better support proliferation and migration of rabbit bone mesenchymal stem cells (RBMSCs). After three months postreconstruction of massive rotator cuff tear in a rabbit model using PEUU scaffold, there was complete regeneration of rotator cuff with physical tendon-to-bone interface and continuous tendon tissue, as observed from histological analysis. Further, biomechanical testing demonstrated that rotator cuff induced by PEUU scaffold had no significant difference as compared to normal rotator cuff. This macroporous, mechanically matched scaffold is potentially suitable for the application in massive rotator cuff repair. In conclusion, this study demonstrates the high efficiency of the macroporous 3D scaffold with self-fitting capability in facilitating rotator cuff regeneration.

Arthroscopic partial repair with versus without biodegradable subacromial spacer for patients with massive rotator cuff tears: a case-control study

BACKGROUND

To investigate whether arthroscopic partial repair with the additional use of a biodegradable subacromial spacer would be proven better treatment for irreparable massive rotator cuff tears (MRCT) compared to single arthroscopic partial repair.

METHODS

A matched-pairs case-control study of 32 patients suffering from irreparable MRCT who underwent an arthroscopic partial repair with (Group B: 16 patients) or without (Group A: 16 patients) InSpace Balloon (ISB^®; Orthospace, Caesarea, Israel) implantation was conducted. For the clinical and functional assessment of the patients, the visual analog scale, Constant score, American Shoulder and Elbow Surgeons Shoulder Score (ASES), Range of Motion (RoM), and patients' satisfaction were obtained.

RESULTS

The two groups were matched in all baseline demographic and clinical characteristics (n.s.). All mean final quantitative postoperative clinical and functional scores of group A (partial repair and ISB) and group B (single partial repair), as well as active RoM, were significantly improved (t test) in comparison with the mean preoperative values (p < 0.05). No significant differences were observed between the two groups in relation to the two success rate criteria (ASES minimal clinically important difference or MCID > 17, Constant score MCID > 10.4), as well as pain relief and RoM 12 months after surgery.

CONCLUSION

Arthroscopic partial repair, either with or without ISB implantation, resulted in significantly improved clinical and functional short-term outcomes for the treatment of MRCT. Patients who were treated with combined partial repair and ISB implantation had a potential propensity toward better functional outcomes and higher patient satisfaction compared to the single-partial-repair-treated group. However, given that these differences were not significant, we feel that further studies are required to clarify the potential therapeutic value of ISB implantation in the treatment of irreparable MRCT.

LEVEL OF EVIDENCE

Level III.

CLINICAL TRIALS' REGISTRY

German Clinical Trials Register (WHO International Clinical Trials Registry Platform). ID number: DRKS00014725. Date of registration: 07/05/2018.

Arthroscopic Repair of a "U" Shaped Rotator Cuff Tear: Modified Margin Convergence with a Single Triple-loaded Suture Anchor

Introduction Repair of a "U" shaped rotator cuff tear tends to create extreme tensile forces at the central part of the rotator cuff margin, causing tensile overload and may result in subsequent failure. We describe our technique of repairing the "U" shaped tear in which margin convergence is done using Ethibond (Ethicon Inc., New Jersey) and a single triple-loaded suture anchor. It results in the reduction of the strain and also allows the repair of seemingly irreparable tears. Patients and method We included 10 patients having a "U" shaped degenerative rotator cuff tear. All patients were assessed preoperatively. The University of California at Los Angeles Shoulder score (UCLA shoulder score) recorded preoperatively and at final follow-up was used to assess functional outcome. Result Out of 10 patients, six were males and four were females. The mean age was 60 years (range 50-70 years). The average follow-up was for 31 months (range 24 - 48 months). The UCLA score increased from an average of 9 preoperatively (range 8 - 12) to an average of 29.6 (range 27 - 31) at the terminal follow-up. The UCLA increased in the postoperative period and was statistically significant (unpaired t-test; p < 0.0001). All patients had good/excellent outcomes (UCLA score > 27). Abduction increased from average 27 degree preoperatively (range 20 degree - 35 degree) to an average 131 degree (range 125 degree - 140 degree) at final follow-up (unpaired t-test; p < 0.0001). Conclusion Our technique of modified margin convergence achieves low tension repair and anatomical footprint reconstruction with good clinical outcomes using a single triple-loaded anchor.

Vascularization and biocompatibility of poly(ε-caprolactone) fiber mats for rotator cuff tear repair

Rotator cuff tear is the most frequent tendon injury in the adult population. Despite current improvements in surgical techniques and the development of grafts, failure rates following tendon reconstruction remain high. New therapies, which aim to restore the topology and functionality of the interface between muscle, tendon and bone, are essentially required. One of the key factors for a successful incorporation of tissue engineered constructs is a rapid ingrowth of cells and tissues, which is dependent on a fast vascularization. The dorsal skinfold chamber model in female BALB/cJZtm mice allows the observation of microhemodynamic parameters in repeated measurements in vivo and therefore the description of the vascularization of different implant materials. In order to promote vascularization of implant material, we compared a porous polymer patch (a commercially available porous polyurethane based scaffold from Biomerix™) with electrospun polycaprolactone (PCL) fiber mats and chitosan-graft-PCL coated electrospun PCL (CS-g-PCL) fiber mats in vivo. Using intravital fluorescence microscopy microcirculatory parameters were analyzed repetitively over 14 days. Vascularization was significantly increased in CS-g-PCL fiber mats at day 14 compared to the porous polymer patch and uncoated PCL fiber mats. Furthermore CS-g-PCL fiber mats showed also a reduced activation of immune cells. Clinically, these are important findings as they indicate that the CS-g-PCL improves the formation of vascularized tissue and the ingrowth of cells into electrospun PCL scaffolds. Especially the combination of enhanced vascularization and the reduction in immune cell activation at the later time points of our study points to an improved clinical outcome after rotator cuff tear repair.

Vascular endothelial growth factor enhances tendon-bone healing by activating Yes-associated protein for angiogenesis induction and rotator cuff reconstruction in rats

Local angiogenesis following rotator cuff reconstruction is crucial for tendon-bone healing. The current research on the mechanism underlying angiogenesis that promotes tendon-bone healing is scarce. This study investigates the mechanism underlying vascular endothelial growth factor (VEGF)-Hippo signaling pathway's involvement in tendon-bone healing following rotator cuff reconstruction. Verteporfin, the inhibitor of the Yes-associated protein (YAP), was used to mechanically test and analyze two groups of tensile-failure loads following rotator cuff reconstruction and to detect collagen and angiogenesis-related marker expressions in the tendon. The interaction mechanism of the VEGF-Hippo signaling pathway was assessed using human umbilical vein endothelial cells (HUVECs). The diameter of the supraspinatus tendon reduced following verteporfin treatment. Mechanical tests revealed that verteporfin significantly reduces the tensile-failure load of the supraspinatus tendon. Verteporfin significantly reduces collagen 1 (Col 1), Col 3, Angiopoietin 2, CD31, Von Willebrand factor, CTGF, and CYR61 expressions. In HUVECs, VEGF activates VEGF receptors and inhibits LATS and YAP phosphorylation. YAP is then transferred to the nucleus to further activate downstream pathways. Therefore, verteporfin can inhibit VEGF-induced YAP pathway activation by inhibiting YAP activity. Angiogenesis in tendon-bone healing following rotator cuff reconstruction requires VEGF-Hippo signaling pathway synergy.

Promoting tendon to bone integration using graphene oxide-doped electrospun poly(lactic-co-glycolic acid) nanofibrous membrane

Background

These normal entheses are not reestablished after repair despite significant advances in surgical techniques. There is a significant need to develop integrative biomaterials, facilitating functional tendon-to-bone integration.

Materials and methods

We fabricated a highly interconnective graphene oxide-doped electrospun poly(lactide-co-glycolide acid) (GO-PLGA) nanofibrous membrane by electrospinning technique and evaluated them using in vitro cell assays. Then, we established rabbit models, the PLGA and GO-PLGA nanofibrous membranes were used to augment the rotator cuff repairs. The animals were killed postoperatively, which was followed by micro-computed tomography, histological and biomechanical evaluation.

Results

GO was easily mixed into PLGA filament without changing the three dimensional microstructure. An in vitro evaluation demonstrated that the PLGA membranes incorporated with GO accelerated the proliferation of BMSCs and furthered the Osteogenic differentiation of BMSCs. In addition, an in vivo assessment further revealed that the local application of GO-PLGA membrane to the gap between the tendon and the bone in a rabbit model promoted the healing enthesis, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with repair with PLGA only.

Conclusion

The electrospun GO-PLGA fibrous membrane provides an effective approach for the regeneration of tendon to bone enthesis.

Perioperative Serum 25-Hydroxyvitamin D Levels Affect Revision Surgery Rates After Arthroscopic Rotator Cuff Repair

PURPOSE

To examine any association between perioperative serum 25-hydroxyvitamin D levels and failure of arthroscopic rotator cuff repair (RCR) requiring revision surgery.

METHODS

Using a private-payer national insurance database, patients who underwent arthroscopic RCR with perioperative serum 25-hydroxyvitamin D levels recorded were included. Patients were stratified into groups of (1) serum 25-hydroxyvitamin D deficiency (<20 ng/mL), (2) insufficiency (20-30 ng/mL), or (3) sufficient (>30-<150 ng/mL). The primary outcome measure was ipsilateral revision rotator cuff surgery, including revision repair, debridement, or reverse shoulder arthroplasty. A multivariable logistic regression analysis was used to control for patient demographics and comorbidities during comparisons.

RESULTS

A total of 982 patients were included in the study. The rate of revision rotator cuff surgery was significantly higher in patients in the serum 25-hydroxyvitamin D-deficient group (5.88%) compared with the serum 25-hydroxyvitamin D-sufficient control group (3.7%) (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.6-5.8; P = .007). Patients with serum 25-hydroxyvitamin D deficiency (5.88%) also had a significantly higher incidence of revision surgery compared with patients with serum 25-hydroxyvitamin D insufficiency (OR, 2.4; 95% CI, 1.5-3.9; P = .011). There was no significant difference in the incidence of revision surgery in the serum 25-hydroxyvitamin D-insufficient group (4.97%) compared with the serum 25-hydroxyvitamin D-sufficient control group (3.7%) (OR, 1.4; 95% CI, 0.8-2.3; P = .250). The absolute risk reduction of revision surgery for 25-hydroxyvitamin D-deficient patients compared with controls was 2.2%, corresponding to a number needed to treat to avoid 1 revision surgery of 46 patients, relative risk reduction = 0.59.

CONCLUSIONS

Although the present study found a significant statistical association between serum 25-hydroxyvitamin D deficiency and insufficiency and the rate of revision rotator cuff surgery after primary arthroscopic RCR, the absolute differences of these revision rates are minimal and are accompanied with overlapping confidence intervals limiting the clinical significance of these findings.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Porcine Dermal Xenograft as Augmentation in the Treatment of Large Rotator Cuff Tears: Clinical and Magnetic Resonance Results at 2-Year Follow-Up

Purpose  The aim of the present retrospective study is to describe the results obtained at 2-year follow-up by using a porcine dermis-derived collagen membrane implanted as augmentation to treat large rotator cuff tears.

Methods  Thirty-five patients in total were included according to the following criteria: large or massive rotator cuff tear, confirmed during surgery, measuring between 3 and 5 cm in width and stage 1 to 2 fatty infiltration documented at magnetic resonance imaging (MRI). Patients underwent arthroscopic repair of the cuff augmented by the implantation of a porcine dermal collagen membrane. Patients were evaluated up to 24 months after surgery by the Constant score and MRI imaging to assess functional outcomes and re-tear rate. The results obtained were compared to those of a matched cohort of 35 patients operated by arthroscopic repair alone by the same surgical team.

Results  The application of the porcine membrane proved to be safe without scaffold-related adverse events documented. A statistically significant difference in the Constant score in favor of the treatment group was documented at the final evaluation ( p  = 0.036 ). Furthermore, a subgroup analysis revealed that patients treated by augmentation and presenting re-tear at MRI showed a significantly higher functional outcome compared with control patients with MRI evidence of re-tear ( p  = 0.0136).

Conclusion  Arthroscopic repair augmented by porcine dermal xenograft for the treatment of chronic and retracted rotator cuff tears with low-grade fatty degeneration proved to be safe and also effective, with higher functional score compared with the arthroscopic repair alone.

Level of Evidence  This is a Level III, retrospective cohort study.

Short-term results of rotator cuff repair using GraftJacket as an interpositional tissue-matched thickness graft

We report outcomes of using GraftJacket to repair massive rotator-cuff-tears. Twenty patients with a mean age of 64.6y over 12-month duration were reviewed. Two patients had a single GraftJacket repair (group1), whilst 18 had the GraftJacket sheet doubled (group2). Pre and post oxford shoulder scores (OSS) and patient related outcome measures were evaluated. A statistically significant improvement of OSS was demonstrated in-group 2 from a mean of 22 to 45.5 (p < 0.00148) over a follow up of 18 months. GraftJacket is a safe and effective procedure to use as an interpositional graft and doubling the graft may improve outcomes.

Rotator cuff tendon-to-bone healing at 12 months after patch grafting of acellular dermal matrix in an animal model

There is no report to investigate the histology and biomechanical strength of remodeled tendon-to-bone junction more than 6 months after patch grafting with acellular dermal matrix (ADM) on rotator cuff defect. We investigated those 12 months after surgery and hypothesized that a new native enthesis is not regenerated and the biomechanical strength is inferior to normal control. Adult male Sprague-Dawley rats underwent ADM patch grafting for the rotator cuff defect. Quantitative histological analysis, immunohistochemical analysis for collagen type I and III, and biomechanical testing were performed 12 months after surgery. The controls were unoperated age-matched rats. In the grafted rats, the collagen arrangement was more irregular and the fibrocartilage layer was smaller at the tendon-bone interface than in the controls although dense collagen fibers in the remodeled tendon were observed; the number of chondrocytes, the percentage of chondrocytes aligned in rows, and the area of the fibrocartilage layer were significantly smaller than in the control group (p = 0.0252, 0.0039, and 0.0252, respectively). Grafted specimens showed significantly lower collagen organization in the midsubstance and tendon-bone interface than the controls (p = 0.0252 and 0.0374, respectively). Immunohistochemical analysis demonstrated that the remodeled tendon fibers were stained more strongly for type III than type I. At 12 months postoperatively, the ultimate load to failure was significantly lower in the graft group than normal control (p = 0.0026); that was 47.8% of normal controls. 12 months after rotator cuff patch grafting with ADM, the formation of a new enthesis grossly resembled the native structure but there was poor cellular organization and the biomechanical strength of remodeled tendon-to-bone was only 48% of normal controls. Advances in tissue engineering and postoperative rehabilitation are needed to promote the healing process after rotator cuff patch grafting.

Interposition Dermal Matrix Xenografts: A Successful Alternative to Traditional Treatment of Massive Rotator Cuff Tears

BACKGROUND

Management of massive rotator cuff tears in shoulders without glenohumeral arthritis remains problematic for surgeons. Repairs of massive rotator cuff tears have failure rates of 20% to 94% at 1 to 2 years postoperatively as demonstrated with arthrography, ultrasound, and magnetic resonance imaging. Additionally, inconsistent outcomes have been reported with debridement alone of massive rotator cuff tears, and limitations have been seen with other current methods of operative intervention, including arthroplasty and tendon transfers.

HYPOTHESIS

The use of interposition porcine acellular dermal matrix xenograft in patients with massive rotator cuff tears will result in improved subjective outcomes, postoperative pain, function, range of motion, and strength.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Sixty patients (61 shoulders) were prospectively observed for a mean of 50.3 months (range, 24-63 months) after repair of massive rotator cuff tears with porcine acellular dermal matrix xenograft as an interposition graft. Subjective outcome data were obtained with visual analog scale for pain score (0-10, 0 = no pain) and Modified American Shoulder and Elbow Surgeons (MASES) score. Active range of motion in flexion, external rotation, and internal rotation were recorded. Strength in the supraspinatus and infraspinatus muscles was assessed manually on a 10-point scale and by handheld dynamometer. Ultrasound was used to assess the integrity of the repair during latest follow-up.

RESULTS

Mean visual analog scale pain score decreased from 4.0 preoperatively to 1.0 postoperatively ( P < .001). Mean active forward flexion improved from 140.7° to 160.4° ( P < .001), external rotation at 0° of abduction from 55.6° to 70.1° ( P = .001), and internal rotation at 90° of abduction from 52.0° to 76.2° ( P < .001). Supraspinatus manual strength increased from 7.7 to 8.8 ( P < .001) and infraspinatus manual strength from 7.7 to 9.3 ( P < .001). Mean dynamometric strength in forward flexion was 77.7 N in nonoperative shoulders (shoulder that did not undergo surgery) and 67.8 N ( P < .001) in operative shoulders (shoulder that underwent rotator cuff repair with interposition porcine dermal matrix xenograft). Mean dynamometric strength in external rotation was 54.5 N in nonoperative shoulders and 50.1 N in operative shoulders ( P = .04). Average postoperative MASES score was 87.8. Musculoskeletal ultrasound showed that 91.8% (56 of 61) of repairs were fully intact; 3.3% (2 of 61), partially intact; and 4.9% (3 of 61), not intact.

CONCLUSION

Patients who underwent repair of massive rotator cuff tears with interposition porcine acellular dermal matrix graft have good subjective function as assessed by the MASES score. Patients have significant improvement in pain, range of motion, and manual muscle strength. Postoperative ultrasound demonstrated that the repair was completely intact in 91.8% of patients, a vast improvement compared with results previously reported for primary repairs of massive rotator cuff tears.

Icariin Promotes Tendon-Bone Healing during Repair of Rotator Cuff Tears: A Biomechanical and Histological Study

To investigate whether the systematic administration of icariin (ICA) promotes tendon-bone healing after rotator cuff reconstruction in vivo, a total of 64 male Sprague Dawley rats were used in a rotator cuff injury model and underwent rotator cuff reconstruction (bone tunnel suture fixation). Rats from the ICA group (n = 32) were gavage-fed daily with ICA at 0.125 mg/g, while rats in the control group (n = 32) received saline only. Micro-computed tomography, biomechanical tests, serum ELISA (calcium; Ca, alkaline phosphatase; AP, osteocalcin; OCN) and histological examinations (Safranin O and Fast Green staining, type I, II and III collagen (Col1, Col2, and Col3), CD31, and vascular endothelial growth factor (VEGF)) were analyzed two and four weeks after surgery. In the ICA group, the serum levels of AP and OCN were higher than in the control group. More Col1-, Col2-, CD31-, and VEGF-positive cells, together with a greater degree of osteogenesis, were detected in the ICA group compared with the control group. During mechanical testing, the ICA group showed a significantly higher ultimate failure load than the control group at both two and four weeks. Our results indicate that the systematic administration of ICA could promote angiogenesis and tendon-bone healing after rotator cuff reconstruction, with superior mechanical strength compared with the controls. Treatment for rotator cuff injury using systematically-administered ICA could be a promising strategy.

Patch-augmented rotator cuff repair: influence of the patch fixation technique on primary biomechanical stability

INTRODUCTION

There is an ongoing debate about the potential of patch augmentation to improve biomechanical stability and healing associated with rotator cuff repair. The biomechanical properties of three different patch-augmented rotator cuff repair techniques were assessed in vitro and compared with a standard repair. Dermal collagen patch augmentation may increase the primary stability and strength of the repaired tendon in vitro, depending on the technique used for patch application.

METHODS AND MATERIALS

Forty cadaveric sheep shoulders with dissected infraspinatus tendons were randomized into four groups (n = 10/group) for tendon repair using a knotless double-row suture anchor technique. A xenologous dermal extracellular matrix patch was used for augmentation in the three test groups using an "integrated", "cover", or "hybrid" technique. Tendons were preconditioned, cyclically loaded from 10 to 30 N at 1 Hz, and then loaded monotonically to failure. Biomechanical properties and the mode of failure were evaluated.

RESULTS

Patch augmentation significantly increased the maximum load at failure by 61 % in the "cover" technique test group (225.8 N) and 51 % in the "hybrid" technique test group (211.4 N) compared with the non-augmented control group (140.2 N) (P ≤ 0.015). For the test group with "integrated" patch augmentation, the load at failure was 28 % lower (101.6 N) compared with the control group (P = 0.043). There was no significant difference in initial and linear stiffness among the four experimental groups. The most common mode of failure was tendon pullout. No anchor dislocation, patch disruption or knot breakage was observed.

CONCLUSION

Additional patch augmentation with a collagen patch influences the biomechanical properties of a rotator cuff repair in a cadaveric sheep model. Primary repair stability can be significantly improved depending on the augmentation technique.

Biologic Treatments for Sports Injuries II Think Tank-Current Concepts, Future Research, and Barriers to Advancement, Part 2: Rotator Cuff

Rotator cuff tears are common and result in considerable morbidity. Tears within the tendon substance or at its insertion into the humeral head represent a considerable clinical challenge because of the hostile local environment that precludes healing. Tears often progress without intervention, and current surgical treatments are inadequate. Although surgical implants, instrumentation, and techniques have improved, healing rates have not improved, and a high failure rate remains for large and massive rotator cuff tears. The use of biologic adjuvants that contribute to a regenerative microenvironment have great potential for improving healing rates and function after surgery. This article presents a review of current and emerging biologic approaches to augment rotator cuff tendon and muscle regeneration focusing on the scientific rationale, preclinical, and clinical evidence for efficacy, areas for future research, and current barriers to advancement and implementation.

Ultrasound determination of rotator cuff tear repairability

BACKGROUND

Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability.

METHODS

The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability.

RESULTS

Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p < 0.0001) and a specificity of 67% (p < 0.0001). The strongest predictors of rotator cuff repairability were tear size (p < 0.001) and age (p = 0.004). Sonographic assessments of tear size ≥4 cm(2) or anteroposterior tear length ≥25 mm indicated an irreparable rotator cuff tear.

CONCLUSIONS

Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability.

[Clinical management of rotator cuff tears. Current concepts in cell-based therapy strategies]

Due to the increasing demand for functionality in an aging yet physically active society, the treatment of rotator cuff tears is of ever-growing importance. Despite intensive research efforts, the treatment of degenerative rotator cuff tears, in particular their long-term outcome, is still a challenge. While in recent years the focus was on biomechanics and the technical aspects of rotator cuff reconstruction, attention has now turned to the biological considerations of tendon regeneration. This article highlights the current state of biological rotator cuff augmentation in a clinical setting and provides an insight into and an outlook on the experimental procedures.

Single-versus double-row arthroscopic rotator cuff repair in massive tears

Background

It is a challenge for orthopaedic surgeons to treat massive rotator cuff tears. The optimal management of massive rotator cuff tears remains controversial. Therefore, the goal of this study was to compare arthroscopic single- versus double-row rotator cuff repair with a larger sample size.

Material/Methods

Of the subjects with massive rotator cuff tears, 146 were treated using single-row repair, and 102 were treated using double-row repair. Pre- and postoperative functional outcomes and radiographic images were collected. The clinical outcomes were evaluated for a minimum of 2 years.

Results

No significant differences were shown between the groups in terms of functional outcomes. Regarding the integrity of the tendon, a lower rate of post-treatment retear was observed in patients who underwent double-row repair compared with single-row repair.

Conclusions

The results suggest that double-row repair is relatively superior in shoulder ROM and the strength of tendon compared with single-row repair. Future studies involving more patients in better-designed randomized controlled trials will be required.

Results of reconstruction of massive irreparable rotator cuff tears using a fascia lata allograft

BACKGROUND

Despite the advances in surgical treatment options, massive rotator cuff (r-c) tears still represent a challenge for orthopedic surgeons. This study assesses the effectiveness of fascia lata allograft in reconstruction of massive and irreparable r-c tear and to evaluate the healing and functional outcomes.

MATERIALS AND METHODS

68 patients (38 men, 30 women, mean age 64.9 years) with massive or irreparable r-c tears were treated with placement of fascia lata allograft to fill the defect between February 2006 and February 2010. At 43 months followup they were evaluated clinically using the constant score, preoperatively and postoperatively. Magnetic resonance imaging (MRI) and ultrasound were used postoperatively, to assess the integrity of the allograft at the repair site. Postoperatively, standard rehabilitation protocol was followed with gradual restoration.

RESULTS

Postoperative constant score increased from 32.5 preoperatively to 88.7 postoperatively. The most important was the pain relief from 2.4 preoperatively to 14.1 postoperatively and range of motion. The results of the MRI were not reliable, but the ultrasound was satisfactory. Finally, there was no infection or rejection of the graft in any of the patients.

CONCLUSIONS

Despite advances in surgical methods, there is still not a universally accepted treatment for massive and irreparable rotator cuff tears, because the standard methods have dubious results, with excessive retear rates and poor outcomes, necessitating the need for new repair strategies. We documented significant clinical improvement using fascia lata allograft in the repair of massive irreparable r-c tear, acting as scaffold to bridge the defect, enhancing the healing at the repair site.

Human dermal allograft for massive rotator cuff tears

Previously published studies reported variable results using various suture techniques and reconstruction options for massive rotator cuff tears. Therefore, the current authors retrospectively studied 21 consecutive patients/shoulders with massive rotator cuff tears treated from January 2005 to October 2011 with a human dermal allograft through a mini-open approach. Mean patient age was 58 years (range, 33-72 years). Mean follow-up was 29 months (range, 18-52 months). Ten patients underwent revision repair for a failed rotator cuff repair. The authors measured the tendon gap (mean, 1.7 cm) and acromiohumeral interval (mean, 6.5 mm). They evaluated pain, shoulder range of motion (ROM) and function, patient satisfaction with the operation and outcome, and complications. At last follow-up, all patients experienced significant pain relief (P=.001) and improved ROM (P=.001) and American Shoulder and Elbow Surgeons (ASES) score (P=.001). Eighteen patients reported that they were satisfied or very satisfied and 3 reported that they were not satisfied with the operation and outcome. Comparison of outcomes between patients who underwent primary repair and those who underwent revision repair and between patients who had muscle atrophy and fatty infiltration grades 0 to II and those who had grades III to IV showed no statistically significant differences. A statistically significant correlation was observed between the size of the tendon gap and postoperative pain, ROM (except external rotation), and ASES score (P<.050). No significant correlation was observed between postoperative pain, ROM, and ASES score and the acromiohumeral interval (P>.050). Complications related to the dermal human allograft were not observed.

The biomechanical effects of polytetrafluoroethylene suture augmentations in lateral-row rotator cuff repairs in an ovine model

BACKGROUND

This study investigated the biomechanical effects of expanded polytetrafluoroethylene (ePTFE) suture augmentation patches in rotator cuff repair constructs.

METHODS

The infraspinatus tendon in 24 cadaveric ovine shoulders was repaired using an inverted horizontal mattress suture with 2 knotless bone anchors (ArthroCare, Austin, TX, USA) in a lateral-row configuration. Four different repair groups (6 per group) were created: (1) standard repair using inverted horizontal mattress sutures, (2) repair with ePTFE suture augmentations on the bursal side of the tendon, (3) repair with ePTFE suture augmentations on the articular side, and, (4) repair with ePTFE suture augmentations on both sides of the tendon. Footprint contact pressure, stiffness, and the load to failure of the repair constructs were measured.

RESULTS

Repairs with ePTFE suture augmentations on the bursal side exerted significantly more footprint contact pressure (0.40 ± 0.01 MPa) than those on the articular side (0.34 ± 0.02 MPa, P = .04) and those on both sides (0.33 ± 0.02 MPa, P = .01). At 15 degrees of abduction, ePTFE-augmented repairs on the bursal side had higher footprint contact pressure (0.26 ± 0.03 MPa) compared with standard repairs (0.15 ± 0.02 MPa, P = .01) and with ePTFE-augmented repairs on the articular side (0.18 ± 0.02 MPa, P = .03). The ePTFE-augmented repairs on the bursal side demonstrated significantly higher failure loads (178 ± 18 N) than standard repairs (120 ± 17 N, P = .04).

CONCLUSIONS

Inverted horizontal mattress sutures augmented with ePTFE patches on the bursal side of the tendon enhanced footprint contact pressures and the ultimate load to failure of lateral-row rotator cuff repairs in an ovine model.

Latissimus dorsi tendon transfer for massive, irreparable posterosuperior rotator cuff tears: surgical technique

Massive rotator cuff tears remain a complex and challenging problem for both the patient and the surgeon. Although significant advancements in surgical techniques as well as technology for arthroscopic and mini-open rotator cuff repairs have been made, many massive tears result in failed repair with continued progressive tendon retraction and degeneration. In cases when primary tendon to bone healing is impractical, latissimus dorsi tendon transfer provides promising and reproducible clinical results. Herein, we present a latissimus tendon transfer surgical technique, a procedure we have used as a salvage operation for failed arthroscopic/mini-open primary rotator cuff repair.

Effect of Postoperative Passive Motion on Rotator Cuff Reconstruction With Acellular Dermal Matrix Grafts in a Rat Model

BACKGROUND

Although postoperative rehabilitation is critical for rotator cuff tendon-to-bone healing and shoulder function recovery, no standardized protocol has been established.

HYPOTHESIS

Postoperative immediate passive motion is detrimental to tendon-to-bone remodeling and tendon maturation after rotator cuff acellular dermal matrix (ADM) grafting, although postoperative delayed passive motion does no harm.

STUDY DESIGN

Controlled laboratory study.

METHODS

Male Sprague-Dawley rats underwent rotator cuff reconstruction with ADM grafts. Their shoulders were immobilized for 2 weeks thereafter. The rats were assigned to 3 different rehabilitation protocols: (1) immobilization without passive motion (nonpassive motion [N-PM], controls), (2) immobilization with immediate passive motion (I-PM), and (3) immobilization with delayed passive motion (D-PM). Specimens obtained 2, 6, and 12 weeks postoperatively were analyzed histologically, and semiquantitative histomorphological measurements of collagen organization, vascularity, and cellularity were obtained; the area of interest was divided into 2 zones, the midsubstance of the graft and the graft-bone interface. Another set of samples taken at 12 weeks was subjected to biomechanical analysis.

RESULTS

At 2 weeks, there was no significant difference among the groups in terms of semiquantitative histomorphological measurements of collagen organization, vascularity, and cellularity. At 6 weeks, collagen organization at the insertion site was significantly poorer in I-PM than in N-PM and D-PM rats (P = .0095). At 12 weeks, collagen organization at the insertion site and midsubstance of ADM grafts was also significantly poorer in I-PM rats (P = .0125 and P = .0018, respectively), and ultimate load-to-failure was lower in this group (P = .0043).

CONCLUSION

While postoperative immediate passive motion was detrimental to remodeled tendon-to-bone healing and to the tendon maturation of ADM grafts placed in the rotator cuff tendon defects, delayed passive motion did no harm.

CLINICAL RELEVANCE

For patients with 6-week immobilization after rotator cuff reconstruction, we recommend that early passive motion be started no sooner than 3 weeks after surgery. Immediate early passive motion should be avoided.

Irreparable rotator cuff tears: a novel classification system

BACKGROUND

Irreparable rotator cuff tears can be managed by several approaches. However, current tear classifications fail to reflect the wide variety of their presentation, which has important clinical and prognostic implications.

METHODS

We describe a novel classification system based on preoperative imaging findings and intraoperative observation where each cuff tendon (numbered sequentially: 1-supraspinatus, 2-infraspinatus, 3-teres minor, and 4-subscapularis) is assessed intraoperatively for reducibility to the footprint; tendons with reparable lesions are assessed for fatty degeneration (which predicts healing potential) and given a plus if degeneration is <50 % (Fuchs stage I-II/Goutallier stage 0-II) or a minus if it is ≥50 % (Fuchs stage III/Goutallier stage III-IV).

RESULTS

The proposed system (1) allows more consistent and reproducible classification of cuff tears where at least one tendon is irreparable; (2) results in more accurate diagnosis; (3) guides in treatment selection; and (4) ensures better outcomes and realistic patient expectations.

CONCLUSIONS

The novel classification system can contribute to develop increasingly exhaustive and reproducible classification models.

Effect of diet-induced vitamin D deficiency on rotator cuff healing in a rat model

BACKGROUND

Few studies have considered hormonal influences, particularly vitamin D, on healing.

HYPOTHESIS

Vitamin D deficiency would have a negative effect on the structure of the healing tendon-bone interface in a rat model and would result in decreased tendon attachment strength.

STUDY DESIGN

Controlled laboratory study.

METHODS

Vitamin D deficiency was induced in 28 male Sprague-Dawley rats using a specialized vitamin D-deficient diet and ultraviolet light restriction. Serum levels of vitamin D were measured after 6 weeks. These vitamin D-deficient animals (experimental group) plus 32 rats with normal vitamin D levels (controls) underwent unilateral detachment of the right supraspinatus tendon from the greater tuberosity of the humerus, followed by immediate repair using bone tunnel suture fixation. The animals were sacrificed at 2- and 4-week intervals after surgery for biomechanical analysis. A paired t test was used to compare serum vitamin D levels at day 0 and at 6 weeks. A nonparametric Mann-Whitney U test was used to compare load-to-failure and stiffness values between the experimental group and controls. Bone density and new bone formation at the tendon insertion site on the greater tuberosity were assessed with micro-computed tomography (CT). The organization of collagen tissue, new bone formation, vascularity at the tendon-bone interface, fibrocartilage at the tendon-bone interface, and collagen fiber continuity between the tendon and bone tissue were evaluated with safranin O and picrosirius red staining.

RESULTS

Blood draws confirmed vitamin D deficiency at 6 weeks compared with time zero/baseline for rats in the experimental group (10.9 ng/mL vs 6.5 ng/mL, respectively; P < .001). Biomechanical testing demonstrated a significant decrease in load to failure in the experimental group compared with controls at 2 weeks (5.8 ± 2.0 N vs 10.5 ± 4.4 N, respectively; P < .006). There was no difference in stiffness at 2 weeks between the control and experimental groups. At 4 weeks, there was no significant difference in load to failure or stiffness between the control and experimental groups. Histological analysis showed less bone formation and less collagen fiber organization in the vitamin D-deficient specimens at 4 weeks as compared with controls. Micro-CT analysis showed no significant difference between groups for total mineral density and bone volume fraction of cortical, whole, or trabecular bone at 4 weeks.

CONCLUSION

The biomechanical and histological data from this study suggest that low vitamin D levels may negatively affect early healing at the rotator cuff repair site.

CLINICAL RELEVANCE

It is estimated that 1 billion people worldwide are vitamin D deficient. In the deficient state, acutely injured rotator cuffs may have a reduced ability for tendon healing. Further studies are needed to determine the exact mechanism by which vitamin D affects tendon healing and whether vitamin D supplementation can improve rotator cuff tendon healing and reduce the incidence of retears.