Radiologic and clinical evaluation of a bioabsorbable collagen implant to treat partial-thickness tears: a prospective multicenter study

Augmentation of a Transosseous-Equivalent Repair in Posterosuperior Nonacute Rotator Cuff Tears With a Bioinductive Collagen Implant Decreases the Retear Rate at 1 Year: A Randomized Controlled Trial

PURPOSE

To determine whether the addition of a bioinductive collagen implant (BCI) over a transosseous equivalent (TOE) repair of medium-to-large posterosuperior rotator cuff tears improves the healing rate determined by magnetic resonance imaging (MRI) at 12-month follow-up.

METHODS

A Level I randomized controlled trial was performed in 124 subjects with isolated, symptomatic, reparable, full-thickness, medium-to-large posterosuperior nonacute rotator cuff tears, with fatty infiltration ≤2. These were randomized to 2 groups in which an arthroscopic posterosuperior rotator cuff tear TOE repair was performed alone (Control group) or with BCI applied over the TOE repair (BCI group). The primary outcome was the retear rate (defined as Sugaya 4-5) determined by MRI at 12 months of follow-up. Secondary outcomes were characteristics of the tendon (Sugaya grade and thickness of the healed tendon) and clinical outcomes (pain levels, EQ-5D-5L, American Shoulder and Elbow Surgeons, and Constant-Murley scores) at 12 months of follow-up.

RESULTS

Of the 124 randomized patients, 122 (60 in the BCI group and 62 in the Control group) were available for MRI evaluation 12.2 ± 1.02 months after the intervention. There were no relevant differences in preoperative characteristics. Adding the BCI reduced the retear rate (8.3% [5/60] in the BCI group vs 25.8% [16/62] in the Control group, P = .010; relative risk of retear of 0.32 [95% confidence interval 0.13-0.83]). Sugaya grade was also better in the BCI group (P = .030). There were no differences between groups in the percentage of subjects who reached the MCID for CMS (76.7% vs 81.7%, P = .654) or American Shoulder and Elbow Surgeons (75% vs 80%, P = .829), in other clinical outcomes or in complication rates at 12.4 ± 0.73 (range 11.5-17) months of follow-up.

CONCLUSIONS

Augmentation with a BCI of a TOE repair in a medium-to-large posterosuperior rotator cuff tear reduces the retear rate at 12-month follow-up by two-thirds, yielding similar improvements in clinical outcomes and without increased complication rates.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Effect of Porcine-Derived Absorbable Patch-Type Atelocollagen for Arthroscopic Rotator Cuff Repair: A Prospective Randomized Controlled Trial

BACKGROUND

Even though arthroscopic rotator cuff repair is recognized as a standard treatment option, the risk of postoperative retear is a major concern.

PURPOSE

To evaluate the effect of porcine-derived absorbable patch-type atelocollagen during arthroscopic rotator cuff repair.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 64 patients with rotator cuff tears diagnosed on magnetic resonance imaging (MRI) were enrolled prospectively from November 2020 to December 2021. Both groups had repairs using the suture bridge technique. For the atelocollagen group, before securing the lateral anchors, we inserted porcine-derived absorbable patch-type atelocollagen between the footprint and the tendon. On postoperative day 2, the patients underwent MRI to confirm containment of the patch-type atelocollagen. At 6 months and 1 year postoperatively, the signal intensity of the repaired tendon was assessed using MRI. Patients were evaluated using the Constant score as the primary outcome, along with the visual analog scale for pain; range of motion; American Shoulder and Elbow Surgeons score; University of California, Los Angeles, score; and Korean Shoulder Score preoperatively and at 2, 3, 6, and 12 months postoperatively.

RESULTS

No significant changes in the Constant score as primary outcome, pain or other functional scores, and range of motion were observed between the groups at 1 year postoperatively. The patch-type atelocollagen was confirmed to be contained by the time-zero MRI scan taken 2 days postoperatively. Among the 55 patients included in final analysis, 12 retear cases were recorded (21.8% retear rate). A significantly lower retear rate was found in the atelocollagen group, as 3 cases were observed in this group (10.3%) and 9 cases were observed in the conventional repair group (34.6%) (P = .048).

CONCLUSION

The Constant score was not different between the groups. The retear rate after rotator cuff repair was significantly lower in the group that received porcine-derived absorbable patch-type atelocollagen compared with in the conventional group.

REGISTRATION

KCT0005184 (Clinical Research Information Service [CRIS]; https://cris.nih.go.kr).

Arthroscopic Repair of Retracted Large and Massive Rotator Cuff Tears With and Without Augmentation With a Bio-Inductive Collagen Implant Reveals Substantial and Comparable Clinical Improvement

PURPOSE

To compare clinical and imaging results after repair of retracted large and massive full-thickness rotator cuff tears, including revision repairs, with and without augmentation with a bio-inductive collagen implant.

METHODS

The study group comprised 24 patients (17 male subjects) with retracted 2 or 3 tendon rotator cuff tears undergoing arthroscopic repair followed by onlay augmentation with a bio-inductive collagen implant. The control group comprised 24 patients (19 male subjects) matched by tear size undergoing repair without augmentation. Mean patient age at repair in both groups was 61 years. Active range of motion and patient-reported outcomes were recorded before and after surgery. Noncontrast high-field magnetic resonance imaging was obtained in 20 of 24 collagen implant patients and 17 of 24 control patients at minimum 6 months' follow-up to assess tendon healing.

RESULTS

American Shoulder and Elbow Surgeons and Simple Shoulder Test scores improved from 35 to 86 and 3.6 to 9.3, respectively, in the collagen implant group and from 39 to 87 and 3.9 to 9.7 in the control group. The visual analog score-pain improved from 6.0 to 0.9 and from 5.9 to 0.9 in the collagen implant and control groups, respectively (P < .001 for all). Overall improvements in range of motion and patient-reported outcomes were similar in both groups. Magnetic resonance imaging revealed intact repairs in 11 of 20 (55%) patients in the patch group and 9 of 17 (53%) in the control group. Two patients in each group were revised to reverse shoulder arthroplasty.

CONCLUSIONS

Arthroscopic repair of retracted large and massive rotator cuff tears, including revision repairs, with and without augmentation using a bio-inductive collagen implant results in substantial and comparable early clinical improvement, although predictable healing remains elusive. Further work is needed to optimize patient selection for massive rotator cuff repair and define more precisely the indications for augmentation of these repairs using the collagen implant.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Editorial Commentary: Acellular Collagen Matrix Patch Augmentation of Large Rotator Cuff Tear Repair Results in Improved Healing

Despite a high retear rate, repair of large rotator cuff tendon tear repairs shows good clinical outcomes. Unfortunately, these results often deteriorate with time, and large tears, not to mention progressively symptomatic retears, especially in compromised rotator cuff tissue, remain a problem. The solution could include augmenting repair with a patch such as an acellular collagen matrix. Proper patient selection is needed to achieve a benefit justifying the added expense and operative time associated with adding a patch. Biomechanically, such patches are strong and increase suture retention, as well as repair construct strength and stiffness. Patches provide a significant healing effect. Recent research and meta-analysis support the use of patches on rotator cuff tendon tears 3 cm or larger, whereas smaller tears (1-2 cm in length) appear to heal without the need for a patch.

A scoping review and best evidence synthesis for treatment of partial-thickness rotator cuff tears

BACKGROUND

Rotator cuff disorders include a broad spectrum of pathological conditions including partial-thickness and full-thickness tears. Studies have shown partial-thickness rotator cuff tear (PTRCT) prevalence to be twice that of full-thickness tears. In the working population, PTRCTs are one of the most common causes of shoulder pain and often result in occupational disability due to pain, stiffness, and loss of shoulder function. Treatment of PTRCTs remains controversial. The purpose of this study was to consolidate the existing high-quality evidence on best management approaches in treating PTRCTs using both nonoperative and operative approaches.

METHODS

A scoping review with best evidence synthesis was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. MEDLINE (OVID), EMBASE (OVID), Cochrane Library (Wiley), SCOPUS, Web of Science Core Collection, CINAHL Plus with Full Text (EBSCOhost), PubMed Central, and Science Direct were searched from 2000 to March 3, 2023. Level 1 studies, and systematic reviews and meta-analyses that included level 1 and 2 studies, were included.

RESULTS

The search yielded 8276 articles. A total of 3930 articles were screened after removing 4346 duplicates. Application of inclusion criteria resulted in 662 articles that were selected for full-text review. Twenty-eight level 1 studies, 1 systematic review, 4 meta-analyses, and 1 network meta-analyses were included in the best evidence synthesis. Nonoperative strategies included injections (ie, platelet-rich plasma, corticosteroid, prolotherapy, sodium hyaluronate, anesthetic, and atelocollagen), exercise therapy, and physical agents. Operative interventions consisted of débridement, shaving of the tendon and footprint, transtendon repair, and traditional suture anchor repair techniques with and without tear completion. Both nonoperative and operative strategies demonstrated effectiveness at managing pain and functional outcome for PTRCTs. The evidence supports the effectiveness of surgical intervention in treating PTRCTs regardless of arthroscopic technique.

CONCLUSION

The results of this scoping review do not support superiority of operative over nonoperative management and suggest that both strategies can be effective at managing pain and functional outcome for PTRCTs. Surgery, however, is the most invasive and costly approach, with the highest risk of complications such as infection. Other variables such as patient expectation, treating practitioner bias, or preference may change which modalities are offered and in what sequence.

Rotator Cuff Augmentation: Its Role and Best Practices

Rotator cuff tears are a common source of pain and impairment in the shoulder. Healing of the rotator cuff tendons following repair has been associated with improved patient outcomes. While there have been many technical improvements in surgical techniques for rotator cuff repair, failure rates are still surprisingly high. Augmentation of these repairs has been shown to help with fixation biomechanics as well as healing rates. The described types of augments include autograft, allograft, xenograft, and synthetic options. This report reviews the commonly available types of augments and some of the outcomes associated with their use.

Economic Evaluation of a Bioinductive Implant for the Repair of Rotator Cuff Tears Compared with Standard Surgery in Italy

INTRODUCTION

Rotator cuff tear (RCT) is a painful, progressive condition resulting from damage to the rotator cuff tendons and is the leading cause of shoulder-related disability. Surgical repair of rotator cuff is an established standard of care (SOC); however, failure of the procedure can occur. In this context, the use of collagen-based bioinductive implant REGENETEN showed long-term improvements in clinical scores. The aim of the study was to assess the cost-effectiveness of REGENETEN combined with SOC (SOC + REGENETEN) compared to SOC alone from both National Healthcare Service (NHS) and societal perspectives in Italy.

METHODS

A decision analytic model was developed to estimate the number of tears healed and costs for the two considered treatment strategies over 1 year. Clinical data were retrieved from the literature, and the clinical pathways for the management of patients with RCTs were retrieved from four key opinion leaders in Italy.

RESULTS

Over a 1-year time horizon, healed lesions were 90.70% and 72.90% for surgical repair of RCTs with and without REGENETEN, respectively. Considering the NHS perspective, mean costs per patient were €7828 and €4650 for the two strategies, respectively, leading to an incremental cost-effectiveness ratio (ICER) of €17,857 per healed tear. From the societal perspective, the mean costs per patient were €12,659 for SOC and €11,784 for REGENETEN, thus showing savings of €4918 per healed tear when the bioinductive implant is used. The sensitivity analyses confirmed the robustness of the model results.

CONCLUSION

In the context of paucity of cost-effectiveness studies, our findings provide additional evidence for clinicians and payers regarding the value of a new treatment option that supports a tailored approach for the management of patients with RCTs.

Augmentation of triceps tendon repair with a bio-inductive collagen scaffold

Two active, adult male patients, one with prior triceps rupture and direct repair, presented with traumatic rupture of the distal triceps tendon. MRI confirmed not only complete rupture with retraction in both, but also signal changes within the tendon, raising concern for healing potential and re-rupture. Surgical repair was performed using heavy, non-absorbable suture and suture anchors in the standard fashion, followed by augmentation with a bovine, bio-inductive collagen scaffold in order to increase tendon thickness and aid with healing capability. This technique is well described for rotator cuff repair augmentation but is a novel technique to the literature in the setting of triceps tendons repair. Both patients returned to full, preinjury activity without complication with sustained results at 3 and 3.5 years postoperatively.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Descriptive and controlled laboratory studies.

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE

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

Biphasic Interpositional Allograft for Rotator Cuff Repair Augmentation Is Safe in an Ovine Model

PURPOSE

To perform a preclinical histologic assessment of a biphasic acellular interpositional cancellous allograft in an ovine model of rotator cuff repair (RCR) designed to better understand its safety profile and effects on tendon healing after RCR.

METHODS

Thirty skeletally mature sheep with clinically normal shoulders with an artificially created degenerative infraspinatus tendon tear were randomized to control and treatment groups. Animals were euthanized at 3 weeks, 6 weeks, and 12 weeks. After gross dissection, rotator cuff specimens were fixed with formalin and polymerized for sectioning and staining. Blinded histologic scores evaluated inflammatory cell infiltrates, signs of degradation, particulate debris, collagen arrangement, neovascularization, and enthesis qualitative measures.

RESULTS

There were no treatment specimens that exhibited histologic signs of a significant infection, inflammatory infiltrate, or foreign body reaction such as granuloma or fibrous capsule formation. Histologic scores in all categories were not significantly different at all time points, including the primary end point mean cumulative inflammatory score (control: 3.66 ± 1.21 vs treated: 4.33 ± 1.51, P = .42), when comparing the treatment and control RCR groups. In general, the degree of tendon healing and host tissue response was essentially equivalent between the 2 groups with observation of low overall levels of inflammation and progressive improvements in collagen organization, reduced tenocyte activity, and fibrocartilaginous enthesis reformation.

CONCLUSIONS

This histologic study demonstrated the use of a biphasic interpositional allograft for RCR augmentation in an ovine model does not generate an inflammatory response or foreign body reaction. Use of the biphasic interpositional allograft resulted in a histological profile that was essentially equivalent to that of a standard RCR at 3-, 6-, and 12-week postoperative timepoints. These findings suggest that a biphasic interpositional allograft is safe for further clinical investigation in humans before broader clinical application.

CLINICAL RELEVANCE

Patch augmentation of RCR is a popular technique that has shown clinical success in improving the likelihood of a successful repair in patients at elevated risk for retear. Newer augmentation technologies are being developed to address the biology at the interface between the bone and soft tissue where failure typically occurs.

Arthroscopic Autologous Coracoacromial Ligament Augment Technique for Particle Thickness of Rotator Cuff with at Least Two Years Follow-Up

OBJECTIVE

Patch technology has been the new technique in the treatment of partial thickness of the rotator cuff tear (PTRCTs) to address the limitation of traditional techniques. Compared with allogeneic patches and artificial materials, coracoacromial ligament is obviously closer to their own biology. The purpose of the study was to evaluate the functional and radiographic outcomes following arthroscopic autologous coracoacromial ligament augment technique for treatment of PTRCTs.

METHOD

This study included three female patients with PTRCTs who underwent arthroscopy operation in 2017 with an average age of 51 years (range from 50 to 52 years). The coracoacromial ligament implant was attached to the bursal side surface of the tendon. The clinical results were evaluated by American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), acromiohumeral distance (AHD) and muscle strength before and 12 months after operation. Magnetic resonance imaging (MRI) was performed 24 months after operation to assess the integrity of the anatomical structure of the original tear site.

RESULT

The average ASES score improved significantly from 57.3 preoperatively to 95.0 at 1-year follow-up. The strength improved significantly from grade 3 preoperatively to grade 5 at 1 year. Two of three patients underwent the MRI at 2-year follow-up. Radiographic released the complete healing of rotator cuff tear. No implant-related serious adverse events were reported.

CONCLUSION

The new technique of using autogenous coracoacromial ligament patch augment provides good clinical results on patients with PTRCTs.

Minimum 10-Year Outcomes After Arthroscopic Repair of Partial-Thickness Supraspinatus Rotator Cuff Tears

BACKGROUND

The prevalence of partial-thickness rotator cuff tears (PTRCTs) has been reported to be 13% to 40% within the adult population, accounting for 70% of all rotator cuff tears. Approximately 29% of PTRCTs will progress to full-thickness tears if left untreated. The long-term clinical course after arthroscopic repair of PTRCTs is not well known.

PURPOSE

To investigate minimum 10-year patient-reported outcomes (PROs) after arthroscopic rotator cuff repair (RCR) of the supraspinatus tendon and to report reoperation and complication rates.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients were included who underwent arthroscopic RCR of a PTRCT performed by a single surgeon between October 2005 and October 2011. Arthroscopic RCR was performed with a transtendon repair of partial, articular-sided supraspinatus tendon avulsions, bursal-sided repair, or conversion into a full-thickness tear and repair. PRO data were collected preoperatively and at a minimum 10 years postoperatively. PRO measures included the American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score, the shortened version of Disabilities of the Arm, Shoulder and Hand score (QuickDASH), the 12-Item Short Form Health Survey Physical Component Summary, and patient satisfaction. Subanalyses were performed to determine if tear location or age was associated with outcomes. Retears, revision surgery, and surgical complications were recorded.

RESULTS

In total, 33 patients (21 men, 12 women) at a mean age of 50 years (range, 23-68) met criteria for inclusion. Follow-up was obtained in 28 (87.5%) of the 32 eligible patients ≥10 years out from surgery (mean, 12 years; range, 10-15 years). Of the 33 PTCRTs, 21 were articular sided and 12 were bursal sided. Of the 33 patients, 26 underwent concomitant biceps tenodesis. At follow-up, the mean PROs were significantly improved when compared with preoperative levels: American Shoulder and Elbow Surgeons score from 67.3 to 93.7 (P < .001), Single Assessment Numeric Evaluation from 70.9 to 91.2 (P = .004), QuickDASH from 22.3 to 6.6 (P < .004), and 12-Item Short Form Health Survey Physical Component Summary from 44.8 to 54.2 (P < .001). Median postoperative satisfaction was 10 (range, 5-10). No patient underwent revision surgery.

CONCLUSION

Arthroscopic repair of PTRCTs results in excellent clinical outcomes and high patient satisfaction at minimum 10-year follow-up. Furthermore, the procedure is highly durable, with a clinical survivorship rate of 100% at 10 years.

Revision Rotator Cuff Repair With Versus Without an Arthroscopically Inserted Onlay Bioinductive Implant in Workers' Compensation Patients

Background

The addition of onlay biological grafts to augment difficult rotator cuff repairs has shown encouraging results in a case series.

Purpose/Hypothesis

The purpose of this study was to determine whether the addition of an onlay bioinductive implant would improve repair integrity, shear wave elastographic appearance of the repaired tendon and patch, and patient-rated and/or surgeon-measured shoulder function when used in workers' compensation patients undergoing revision arthroscopic rotator cuff repair. We hypothesized that the addition of the bioinductive implant would enhance repair integrity and clinical outcomes compared with standard repair.

Study Design

Cohort study; Level of evidence, 3.

Methods

A post hoc matched-cohort study was conducted on prospectively recruited workers' compensation patients who received a bioinductive implant for revision rotator cuff repair (n = 19). The control group was selected from consecutive workers' compensation revision rotator cuff repair patients before the introduction of bioinductive implants. Then, they were matched for age and tear size (n = 32). Kaplan-Meier curves were generated to compare the primary outcome of repair integrity between groups. The secondary outcomes were to evaluate the elastographic appearance of the tendon and patch in the bioinductive implant group and to compare patient-rated and surgeon-measured shoulder function between groups preoperatively and at 1 week, 6 weeks, 3 months, and 6 months postoperatively.

Results

No major complications associated with the bioinductive implants were identified. Six months after the revision rotator cuff repair, the retear rate in the bioinductive implant group was 16% (3/19), compared with 19% (6/32) in the age- and tear size-matched control group (P = .458). At the final follow-up, the retear rate in the bioinductive implant group was 47% (9/19) at a mean of 14 months compared with 38% (12/32) at a mean of 29 months in the control group (P = .489). The shear wave elastographic stiffness of repaired tendons augmented with the bioinductive implant remained unchanged at 6 m/s from 1 week to 6 months postoperatively, which is lower than the stiffness of 10 m/s in healthy tendons. There were no significant differences in patient-rated or surgeon-measured outcomes between groups 6 months postoperatively.

Conclusion

There were no differences in repair integrity or clinical outcomes between workers' compensation patients who underwent revision arthroscopic rotator cuff repair with an onlay bioinductive implant compared to those who underwent standard revision rotator cuff repair.

A pilot randomised controlled trial assessing standard versus dermal patch-augmented rotator cuff repair found no adverse effects and suggest future trials need a minimum of 150 patients

PURPOSE

The aims of this pilot randomised controlled trial (RCT) were to assess the safety and efficacy of a human dermal allograft patch and assess the feasibility of a future RCT comparing retear rate and functional outcome 12 months following standard and augmented double-row rotator cuff repair.

METHODS

 A pilot RCT was conducted among patients undergoing arthroscopic repair of rotator cuff tear measuring between 1 and 5 cm. They were randomised to either augmented (double-row repair with human acellular dermal patch) or standard (double-row repair only). The primary outcome was rotator cuff retear determined on MRI scan at 12 months using the Sugaya's classification (grade 4 or 5). All adverse events were recorded. Functional assessment was performed at baseline and 3, 6, 9, and 12 months post-surgery using clinical outcome scores. Safety was assessed by complications and adverse effects, and feasibility by recruitment, follow-up rate and proof of concept statistical analyses of a future trial.

RESULTS

Between 2017 and 2019, 63 patients were considered for inclusion. Twenty-three patients were excluded, leaving 40 patients (20 per group) in the final study population. The mean tear sizes were 3.0 cm in the augmented and 2.4 cm in the standard group. There was one adhesive capsulitis in the augmented group, with no other adverse events. Retear was observed in 4/18 (22%) of patients in the augmented and 5/18 (28%) in the standard group. In both groups, functional outcome improved significantly which was clinically meaningful for all scores, with no difference between groups. Retear rate increased with tear size. Future trials are feasible but need a minimum total sample size of 150 patients.

CONCLUSION

 Clinically meaningful improved function without adverse effects was found with human acellular dermal patch-augmented cuff repairs.

LEVEL OF EVIDENCE

Level II.

Resorbable Bioinductive Collagen Implant Is Cost Effective in the Treatment of Rotator Cuff Tears

Purpose

This study was conducted to investigate whether the use of resorbable bioinductive collagen implant (RBI) in addition to conventional rotator cuff repair (conventional RCR) is cost-effective when compared to conventional RCR alone, in the treatment of full-thickness rotator cuff tears (FT RCT).

Methods

We developed a decision analytic model to compare the expected incremental cost and clinical consequences for a cohort of patients with FT RCT. The probabilities for healing or failure to heal (retear) were estimated from the published literature. Implant and healthcare costs were estimated from a payor's perspective in 2021 U.S. prices. An additional analysis included indirect cost estimations (e.g., productivity losses). Sensitivity analyses explored the effect of tear size, as well as the impact of risk factors.

Results

The base case analysis demonstrated that resorbable bioinductive collagen implant + conventional rotator cuff repair results in incremental costs of $232,468 and an additional 18 healed RCTs per 100 treated patients over 1 year. The estimated incremental cost-effectiveness ratio (ICER) is $13,061/healed RCT compared to conventional RCR alone. When return to work was included in the model, RBI + conventional RCR was found to be cost saving. Cost-effectiveness improved with tear size with the largest benefit seen in massive tears compared to large tears, as well as patients at higher risk of retearing.

Conclusions

This economic analysis demonstrated that RBI + conventional RCR delivered improved healing rates at a marginal increase in costs when compared to conventional RCR alone and is, therefore, cost-effective in this patient population. Considering indirect costs, RBI + conventional RCR resulted in lower costs compared to conventional RCR alone and is, therefore, deemed to be cost saving.

Level of Evidence

Level IV, economic analysis.

Two-year outcomes with a bioinductive collagen implant used in augmentation of arthroscopic repair of full-thickness rotator cuff tears: final results of a prospective multicenter study

BACKGROUND

Full-thickness rotator cuff tears (FTRCTs) represent a common shoulder injury that, if untreated, can progress in size, become increasingly painful, and inhibit function. These lesions are often surgically repaired, with double-row arthroscopic repair often preferred for larger tears. Biological augmentation technologies have been developed to improve rates of postoperative radiographic retear and enhance patient-reported outcomes after surgical FTRCT repair. This study sought to confirm that augmented repair with a bioinductive bovine collagen implant results in favorable retear rates and patient outcomes with follow-up to 2 years.

METHODS

A prospective multicenter cohort study was undertaken to determine the efficacy and safety of augmenting single- or double-row arthroscopic repair of FTRCTs with a bioinductive bovine collagen implant. Of 115 adult patients participating, 66 (57.4%) had medium (1-3-cm) tears and 49 (42.6%) had large (3-5-cm) tears. Magnetic resonance imaging and patient-reported outcomes (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] and Constant-Murley Score [CMS]) were performed and recorded at baseline, 3 months, 1 year, and 2 years.

RESULTS

Mean duration of follow-up was 2.1 years (range, 1.5-2.9 years). Between baseline and 2-year follow-up, mean total thickness of the supraspinatus tendon increased by 12.5% for medium tears and by 17.1% for large tears. Radiographic retear was noted in 7 of 61 available patients (11.5%) with medium tears, and in 14 of 40 patients (35.0%) with large tears. In both groups, these tears primarily occurred before the 3-month follow-up visit (13 of 21 [61.9%]). Radiographic retear with the supplemented double-row (DR) repair technique was 13.2% overall (12 of 91 DR patients; 11.3% for medium tears and 15.8% for large tears). The minimal clinically important difference was achieved by >90% of patients with both medium and large tears for both ASES and CMS. There were 2 serious adverse events classified by the treating surgeon as being possibly related to the device and/or procedure (1 case of swelling/drainage and 1 case of intermittent pain). Nine patients (7.8%; 4 medium tears and 5 large tears) required reoperation of the index rotator cuff surgery.

CONCLUSION

Final 2-year data from this study confirm that using this implant in augmentation of arthroscopic double-row repair of FTRCTs provides favorable rates of radiographic retear and substantial functional recovery. The relative safety of the device is also further supported.

Functional biomaterials for tendon/ligament repair and regeneration

With an increase in life expectancy and the popularity of high-intensity exercise, the frequency of tendon and ligament injuries has also increased. Owing to the specificity of its tissue, the rapid restoration of injured tendons and ligaments is challenging for treatment. This review summarizes the latest progress in cells, biomaterials, active molecules and construction technology in treating tendon/ligament injuries. The characteristics of supports made of different materials and the development and application of different manufacturing methods are discussed. The development of natural polymers, synthetic polymers and composite materials has boosted the use of scaffolds. In addition, the development of electrospinning and hydrogel technology has diversified the production and treatment of materials. First, this article briefly introduces the structure, function and biological characteristics of tendons/ligaments. Then, it summarizes the advantages and disadvantages of different materials, such as natural polymer scaffolds, synthetic polymer scaffolds, composite scaffolds and extracellular matrix (ECM)-derived biological scaffolds, in the application of tendon/ligament regeneration. We then discuss the latest applications of electrospun fiber scaffolds and hydrogels in regeneration engineering. Finally, we discuss the current problems and future directions in the development of biomaterials for restoring damaged tendons and ligaments.

Extracellular Vesicles Delivered by Injectable Collagen Promote Bone-Tendon Interface Healing and Prevent Fatty Degeneration of Rotator Cuff Muscle

PURPOSE

This study aimed (1) to confirm the maintenance of the extracellular vesicles (EVs) delivered via injectable collagen at the application site, and (2) to evaluate the effect of EVs derived from the human umbilical cord-derived mesenchymal stem cells and loaded in an injectable collagen gel after rotator cuff repair (RCR).

METHODS

Rabbits (n = 20) were assigned to normal (N), repair-only (R), and those administered with injectable collagen after repair (RC), and EV-laden injectable collagen after repair (RCE) groups. The EVs isolated by ultra-centrifugation from the human umbilical cord-derived mesenchymal stem cells spent medium were mixed with collagen and administered accordingly. After 12 weeks, the rabbits were sacrificed to evaluate the healing of the bone-to-tendon junction and the fatty degeneration of muscle. Histomorphometric scoring for bone-tendon interface, fatty infiltration (%), and biomechanical tests were performed. Separately, groups of 3 rabbits were assigned to 3 different time points to evaluate maintenance of green fluorescence-labeled EVs with injectable collagen via tracking on the bursal side of the rotator cuff (3 groups: 3 days, 2, and 4 weeks).

RESULTS

The EVs delivered by injectable collagen remained until 4 weeks at the bursal side of the cuff tissue. The RCE group showed a significantly greater histomorphometric total score (P < .001, and P = .013, respectively) and significantly lower fatty degeneration than the RC and R groups (P = .001, and P = .013, respectively). The biomechanical tests revealed significant growing trends in load-to-failure and stiffness (P = .002, and P = .013, respectively), in the R, RC, RCE, and N groups.

CONCLUSIONS

EVs mounted in injectable collagen remained at the repair site for at least 4 weeks after application. Furthermore, they effectively promote bone-to-tendon healing via collagen maturation in bone-tendon interface and preventing fatty degeneration of rotator muscle after RCR as compared with collagen-only or repair-only groups.

CLINICAL RELEVANCE

The combination of collagen with EVs significantly promotes rotator cuff healing demonstrating potential clinical application during partial rotator cuff tear or after RCR.

Bioinductive collagen implants facilitate tendon regeneration in rotator cuff tears

Purpose

To evaluate the clinical outcomes, MRI imaging and histological characteristics of biopsy samples of the tendon from patients in whom rotator cuff repair was previously performed with a bioinductive type I bovine collagen implants.

Methods

Prospective study of 30 patients with partial or complete rotator cuff tears who underwent arthroscopic repair and augmentation with a resorbable type I bovine collagen implant. Preoperatively and at 6 and 12 months after surgery, the VAS, ASES and Constant-Murley scores were evaluated and an MRI study was performed. At 6 months, biopsies of the resulting tissue were obtained and examined histologically.

Results

Patients experienced statistically significant and sustained improvement from baseline for all scores and the mean tendon thickness increased by 1.84 mm. Magnetic resonance imaging evidence of complete healing was found in 27 patients and a considerable reduction in defect size, greater than 50%, was shown in 3. In all samples obtained, the new tissue generated had the histological appearance of a tendon, and was indistinguishable from the native tendon. There was no evidence of any remaining collagen implant.

Conclusions

Biopsies of tissue formed from bioinductive type I bovine collagen implants showed, six months after surgery, the generation of a neotendon indistinguishable from the native one. Histology and MRI imaging, revealed complete integration of the implant and absence of inflammatory or foreign body reactions. The clinical parameters, thickness and MRI signal of the tendon improved significantly at 6 months, regardless of the type and size of the tear, and remained unchanged until 12 months.

Level of evidence

Level IV, case series.

Increased stiffness and reoperation rate in partial rotator cuff repairs treated with a bovine patch: a propensity-matched trial

BACKGROUND

Treating high-grade (grade 2 and 3) partial-thickness rotator cuff tears after failed conservative care remains challenging. Arthroscopic repair techniques are often considered with or without subacromial decompression and biological injections. More recently, a bioinductive bovine collagen patch (Regeneten; Smith & Nephew, Memphis, TN, USA) has been proposed to create a healing response and thicken the injured tendon. Although promising early results have been shown, previous studies lacked control subjects or comparison to other surgical treatments. The purpose of this study was to compare the reoperation rates of arthroscopic débridement and repair without a bioinductive collagen patch vs. arthroscopic débridement and repair with a bioinductive collagen patch in patients with high-grade partial-thickness rotator cuff tears in whom a minimum of 6 months of nonoperative treatment failed.

METHODS

Thirty-two patients with high-grade partial-thickness supraspinatus tears were treated with surgical repair with a bioinductive patch. A control group of 32 patients with high-grade partial-thickness supraspinatus tears treated with débridement or tear completion and repair without a bioinductive patch was selected and matched for age, sex, and tear size. Patients were followed up at regular intervals of 6 weeks, 12 weeks, and 6 months postoperatively, and range of motion was assessed at respective clinic visits. Stiffness and reoperations were compared between groups.

RESULTS

Postoperative stiffness was observed in the first 12 weeks in 8 of 32 patients in the patch group compared with 1 of 32 patients in the control group. Six patients in the patch group underwent reoperations compared with no patients in the control group (P < .001). All 6 reoperations in the patch group were performed to address stiffness. There were no differences in race, smoking status, or diabetes between groups (P > .05).

CONCLUSION

Patients in the patch group had a significantly higher rate of postoperative stiffness. In the majority of patients in whom shoulder stiffness developed, reoperation was required.

Optimal Management of Partial Thickness Rotator Cuff Tears: Clinical Considerations and Practical Management

Partial thickness rotator cuff tears have been diagnosed with increased frequency due to heightened awareness and an improvement in diagnostic modalities. When >50% of the tendon thickness has ruptured, intra-tendinous strain of the residual tendon increases. Surgery is generally confined to patients who have failed non-operative measures and have persistent symptoms. The rationale for repairing partial thickness tears lies in their limited self-healing capacity, and propensity to enlarge over time and progress to a full thickness defect. Although tear debridement and acromioplasty can improve pain and function, tear progression can occur, in addition to worse results being noted in bursal-sided defects. Several surgical strategies have been recommended but there is a lack of evidence to advocate one form of treatment over another. The aim of this narrative review is to discuss the treatment options for partial thickness tears of the rotator cuff.

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.

Diagnosis and Management of Partial Thickness Rotator Cuff Tears: A Comprehensive Review

Partial thickness rotator cuff tears (PRCTs) are a challenging disease entity. Optimal management of PRCTs continues to be controversial. Although advances in magnetic resonance imaging and ultrasonography have aided in early diagnosis, arthroscopic evaluation remains the benchmark for diagnosis. Conservative treatment is often the first line of management for most patients; however, evidence suggests that surgical intervention may limit tear progression and the long-term sequelae. Surgical decision making is driven by factors such as age, arm dominance, etiology, activity level, tear thickness, and tear location. Many surgical options have been described in the literature to treat PRCTs including arthroscopic débridement, transosseous, in situ repair techniques, and tear completion and repair. Biologic supplements have also become an attractive alternative to aid in healing; however, the long-term efficacy of these modalities is largely unknown. This article will provide a detailed review of the etiology and natural history of PRCTs, as well as diagnosis, and current management to guide clinical decision-making and formulate an algorithm for management of PRCTs for the orthopaedic surgeon.

The Evolution of Arthroscopic Rotator Cuff Repair

Over the past 30 years, arthroscopic rotator cuff repair (ARCR) has evolved to become the gold standard in treating rotator cuff pathology. As procedural concepts of ARCR continue to improve, it is also continually compared with the open rotator cuff repair as the historical standard of care. This review highlights the evolution of ARCR, including a historical perspective; the anatomic, clinical, and surgical implications of the development of an arthroscopic approach; how arthroscopy improved some of the problems of the open approach; adaptations in techniques and technologies associated with ARCR; future perspectives in orthobiologics as they pertain to ARCR; and lastly, the clinical improvements, or lack of improvements, with all of these adaptations.

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.

Tips and Tricks for Augmenting Rotator Cuff Repair With a Bio-inductive Collagen Implant

The contemporary literature suggests that a primary feature of recurrence of rotator cuff tear after arthroscopic repair is failure of tendon healing, which can occur for multiple reasons, including compromised tissue quality. Recently, the use of augmentation implants, grafts, or scaffolds has emerged as a strategy to address the issue of deficient rotator cuff tissue. A resorbable bio-inductive collagen implant (REGENETEN; Smith & Nephew, Andover, MA) has been shown to increase tendon thickness when applied in rotator cuff repair. This article presents an experienced surgeon's tips for implanting this device. In addition, we review the current literature about this bio-inductive implant.

Full-Thickness Rotator Cuff Tears Can Be Safely Treated With a Resorbable Bioinductive Bovine Collagen Implant: One-Year Results of a Prospective, Multicenter Registry

Purpose

The purpose of this study was to prospectively collect safety and efficacy data in a large group of patients undergoing arthroscopic repair of full-thickness rotator cuff tears augmented with a resorbable bioinductive bovine collagen implant designed to promote healing.

Methods

Seventeen centers across the United States enrolled patients in an institutional review board-approved registry to collect outcomes data on the implant. Patients undergoing surgical management of full-thickness rotator cuff tears augmented with the implant were enrolled. Inclusion criteria were age of ≥21 years, willingness to participate and the ability to read and speak English. Exclusion criteria included hypersensitivity to bovine-derived products. Patients were assessed before and after surgery at up to 1 year with outcomes including the single-assessment numeric evaluation (SANE), Veterans RAND 12-Item (VR-12) mental components and physical components (VR-12 PCS), American Shoulder and Elbow Surgeons (ASES), and Western Ontario Rotator Cuff (WORC) outcome measures. Ad hoc analyses were performed to compare these outcomes at all time points depending on tear size (small/medium vs large/massive). Serious complications were collected.

Results

Of 210 patients enrolled, 192 had 1-year follow-up data available. The patients experienced statistically significant improvement between baseline and 1 year for mean SANE, VR-12 PCS, ASES, and WORC scores (40.0-82.0, 33.5-47.3, 46.2-87.8, and 36.2-81.0, respectively; P < .001 for all results). Ad-hoc analysis demonstrated that similar results were obtained at 1 year regardless of tear size. Twenty patients (10.4%) experienced serious complications (10.4%), including revision surgery (n = 18), proximal humerus fracture/partial subscapularis tear resulting from multiple falls (n = 1), and adhesive capsulitis (n = 1).

Conclusions

The safety and efficacy of a bioinductive implant in the surgical management of full-thickness rotator cuff tears at 1 year was shown in this study. Implant efficacy appears to be comparable regardless of the underlying tear size.

Level of Evidence

Level IV, therapeutic case series.

Arthroscopic Biological Augmentation for Massive Rotator Cuff Tears: The Biceps-Cuff-Bursa Composite Repair

Surgical repair of massive and chronic rotator cuff tears is difficult due to tendon retraction and severe atrophy, and the resultant retear rate in the structurally weak tendons is high. Commercially available patches and bioinductive scaffolds have been used to provide strength and superior healing environment in partial and complete rotator cuff tears. Biological biceps autograft has been used for superior capsular reconstruction, and the subacromial bursa has been shown to have significant pluripotent stem cell potency for tendon healing. We describe our technique for combined use of the long biceps tendon (LBT) and vasculature-preserved subacromial bursa as autografts in rotator cuff repair augmentation. The technique involves obtaining a LBT graft of sufficient length using a "traction and tenodesis" technique. The subacromial bursa is mobilized as a continuous layer (vascular bursal duvet) by maintaining its medial and lateral vascularity. All-suture anchors are used to minimize the insertion apertures (3 mm) in tuberosity. The bursa is advanced laterally, and the mobilized cuff is repaired together as a biceps-cuff-bursa composite unit. Combined use of the biceps and bursa as biological autografts has the advantage of structural and regenerative augmentation, and the autografts are easily accessible without added cost.

Effect of co-administration of atelocollagen and hyaluronic acid on rotator cuff healing

Background

This study aimed to evaluate the co-administration effect of atelocollagen combined with hyaluronic acid (HA) injections for treatment of full-thickness rotator cuff tear (RCT).

Methods

Eighty patients who underwent arthroscopic rotator cuff repair for full-thickness RCT from March 2018 to November 2019 were enrolled. The patients were randomly allocated to the following groups: combined atelocollagen and HA injection (group I, n=28), only HA injection (group II, n=26), and no injection (group III, n=26). Clinical outcomes were assessed at 3, 6, and 12 months after surgery using the American Shoulder and Elbow Surgeons score, visual analog scale pain score , functional scores (pain visual analog scale, function visual analog score), and range of motion. Magnetic resonance imaging was performed 12 months after surgery to evaluate rotator cuff integrity.

Results

Preoperative demographic data and postoperative clinical outcomes did not differ significantly among the three groups (p>0.05). However, in group I, the number of steroid injections after surgery was significantly lower than that in the other groups (p=0.011). The retear rate on follow-up magnetic resonance imaging was significantly higher in group II (9.5%, n=2) and group III (13.6%, n=3) than in group I (0%) (p=0.021).

Conclusions

Co-administration of atelocollagen and HA improves healing of the rotator cuff and increases the integrity of the rotator cuff repair site. This study provides encouraging evidence for use of combined atelocollagen-HA injections to treat patients with full-thickness RCT.

Treatment of Partial-Thickness Rotator Cuff Tears With a Resorbable Bioinductive Bovine Collagen Implant: 1-Year Results From a Prospective Multicenter Registry

Background:

Surgical treatment of partial-thickness rotator cuff tears remains challenging and controversial, with several traditional options including debridement with acromioplasty, transtendon or in situ repair, and take-down and repair. A resorbable bioinductive bovine collagen implant has shown promise as an alternative treatment option for partial-thickness tears.

Purpose:

Data from a registry were analyzed to further establish that the implant contributes to improved patient-reported outcome (PRO) scores across a large number of patients treated for partial-thickness rotator cuff tears.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 19 centers in the United States enrolled patients >21 years old with partial-thickness tears of the rotator cuff in a comprehensive prospective multicenter registry. PRO scores were recorded preoperatively and postoperatively at 2 and 6 weeks, 3 and 6 months, and 1 year: American Shoulder and Elbow Surgeons, Single Assessment Numeric Evaluation, Veterans RAND 12-Item Health Survey (physical and mental component scores), and Western Ontario Rotator Cuff scores. Revisions were reported throughout the study.

Results:

The registry included 272 patients with partial-thickness tears (49 grade 1 tears, 101 grade 2 tears, and 122 grade 3 tears), 241 who underwent isolated bioinductive repair (IBR; collagen implant placed after bursectomy without a traditional rotator cuff repair), and 31 who had take-down and repair with bioinductive augmentation. Patients experienced statistically significant and sustained improvement from baseline for all PRO scores beginning at 3 months. Among patients with grade ≥2 tears, those with take-down and repair had significantly inferior scores at 2 and 6 weeks for most PRO scores as compared with those who underwent IBR, but the difference was no longer significant at 1 year for all but the physical component score of the Veterans RAND 12-Item Health Survey. There were 11 revisions, which occurred at a mean ± SD of 188.7 ± 88.0 days after the index surgery. There were no infections.

Conclusion:

This registry analysis further establishes across a large data set that this resorbable bioinductive bovine collagen implant improves PROs in all grades of partial-thickness tears, whether used as IBR or in conjunction with take-down and repair. IBR may offer improved early clinical outcomes (≤6 weeks) and comparable outcomes at 1 year when compared with a more invasive “take-down and repair” approach.

Isolated bioinductive repair of partial-thickness rotator cuff tears using a resorbable bovine collagen implant: two-year radiologic and clinical outcomes from a prospective multicenter study

BACKGROUND

Current surgical treatment options for partial-thickness tears (eg, takedown and repair, in situ repair) are limited by the degenerative nature of the underlying tendon and may require extensive intervention that can alter the anatomic footprint. The complexity of available techniques to address these issues led to the development of a resorbable collagen implant, which can be used to create a bioinductive repair of partial-thickness tears.

METHODS

We prospectively enrolled 33 patients with chronic, degenerative, intermediate-grade (n = 12), or high-grade (n = 21) partial-thickness tears (11 articular, 10 bursal, 4 intrasubstance, and 8 hybrid) of the supraspinatus tendon in a multicenter study. After arthroscopic subacromial decompression without a traditional rotator cuff repair, a bioinductive implant was secured over the bursal surface of the tendon. Clinical outcomes were assessed using American Shoulder and Elbow Surgeons (ASES) and Constant-Murley scores (CMS) preoperatively and at 3 months, 1 year, and 2 years postoperatively. Magnetic resonance imaging was performed to assess postoperative tendon healing and thickness at the original tear site.

RESULTS

At 2-year follow-up, mean ASES and CMS scores improved both clinically and statistically at 1 and 2 years, compared with baseline, for intermediate- and high-grade tears. There was magnetic resonance imaging evidence of new tissue fill-in within the original baseline tear in 100% of the intermediate-grade tears and 95% of the high-grade tears. In 90.9% of the intermediate-grade tears and 84.2% of the high-grade tears, this new tissue fill-in represented at least an additional 50% of the volume of the initial lesion. From baseline to 2-year follow-up, the mean tendon thickness increased by 1.2 mm (standard deviation, 1.3; P = .012) and 1.8 mm (standard deviation, 2.2; P = .003) in the intermediate- and high-grade tears, respectively. The analysis of tear grade and location revealed no statistically significant difference in the change in mean tendon thickness at any time point. One patient with a high-grade articular lesion demonstrated progression to a full-thickness tear; however, the patient was noncompliant and the injury occurred while shoveling snow 1 month after surgery. Neither tear location nor treatment of bicep pathology affected the ASES or CMS scores at any follow-up point. No serious adverse events related to the implant were reported.

CONCLUSION

Final results from this 2-year prospective study indicate that the use of this resorbable bovine collagen implant for isolated bioinductive repair of intermediate- and high-grade partial-thickness rotator cuff tears of the supraspinatus is safe and effective, regardless of tear grade and location.

Use of biologics in rotator cuff disorders: Current concept review

Poor tendon to bone healing following rotator cuff repair has led to the continued interest and investigation into biological augmentation. The biology of tendinopathy is not fully understood and consequently the availability of disease modifying therapeutic targets is limited. A ceiling of benefit has been reached by mechanical optimisation of rotator cuff repair and thus, in order to improve healing rates, a biological solution is required. This review focuses on the strategies to biologically augment rotator cuff disorders with an emphasis on rotator cuff repair. Leucocyte rich platelet rich plasma has been shown to improve healing rates without clinically relevant improvements in outcome scores. Similarly, improved healing rates have also been reported with bone marrow stimulation and in long-term follow-up with bone marrow concentrate. Extracellular matrix (ECM) and synthetic scaffolds can increase healing through mechanical and or biological augmentation. A potential third category of scaffold is bio-inductive and has no mechanical support. Studies involving various scaffolds have shown promising results for augmentation of large to massive tears and is likely to be most beneficial when tendon quality is poor, however level I evidence is limited.

Comprehensive collagen crosslinking comparison of microfluidic wet-extruded microfibers for bioactive surgical suture development

Collagen microfiber-based constructs have garnered considerable attention for ligament, tendon, and other soft tissue repairs, yet with limited clinical translation due to strength, biocompatibility, scalable manufacturing, and other challenges. Crosslinking collagen fibers improves mechanical properties; however, questions remain regarding optimal crosslinking chemistries, biocompatibility, biodegradation, long-term stability, and potential for biotextile assemble at scale, limiting their clinical usefulness. Here, we assessed over 50 different crosslinking chemistries on microfluidic wet-extruded collagen microfibers made with clinically relevant collagen to optimize collagen fibers as a biotextile yarn for suture or other medical device manufacture. The endogenous collagen crosslinker, glyoxal, provides extraordinary fiber ultimate tensile strength near 300MPa, and Young's modulus of over 3GPa while retaining 50% of the initial load-bearing capacity through 6 months as hydrated. Glyoxal crosslinked collagen fibers further proved cytocompatible and biocompatible per ISO 10993-based testing, and further elicits a predominantly M2 macrophage response. Remarkably these strong collagen fibers are amenable to industrial braiding to form strong collagen fiber sutures. Collagen microfluidic wet extrusion with glyoxal crosslinking thus progress bioengineered, strong, and stable collagen microfibers significantly towards clinical use for potentially promoting efficient healing compared to existing suture materials. STATEMENT OF SIGNIFICANCE: Towards improving clinical outcomes for over 1 million ligament and tendon surgeries performed annually, we report an advanced microfluidic extrusion process for type I collagen microfiber manufacturing for biological suture and other biotextile manufacturing. This manuscript reports the most extensive wet-extruded collagen fiber crosslinking compendium published to date, providing a tremendous recourse to the field. Collagen fibers made with clinical-grade collagen and crosslinked with glyoxal, exhibit tensile strength and stability that surpasses all prior reports. This is the first report demonstrating that glyoxal, a native tissue crosslinker, has the extraordinary ability to produce strong, cytocompatible, and biocompatible collagen microfibers. These collagen microfibers are ideal for advanced research and clinical use as surgical suture or other tissue-engineered medical products for sports medicine, orthopedics, and other surgical indications.

Current concepts in the evolution of arthroscopic rotator cuff repair

Arthroscopic rotator cuff repair has become one of the most common and successful surgeries performed in orthopedics. It represents the culmination of advances in many diverse fields such as optics, fluid dynamics, mechanical engineering, and most recently, orthobiologics. This article reviews the current state of the art of arthroscopic rotator cuff repair, through the lens of its historical context and evolution to our present understanding. We review the limitations in the current approach, and glance toward the future of rotator cuff regeneration with emerging technologies.

Anterior Cable Tears in Arthroscopic Rotator Cuff Repairs

Purpose

To determine whether anterior cable tears could be identified at the time of arthroscopic rotator cuff repair and determine the characteristics of the anterior cable tears identified.

Methods

From 2016 to 2017 all shoulder arthroscopies had data collected prospectively at the time of surgery, specifically including injury to the capsular and tendon zones of insertion on the greater tuberosity. Anterior cable position and degree of injury and medialization were recorded, as well as complete findings of the diagnostic arthroscopy. The inclusion criterion was primary shoulder arthroscopy. The exclusion criterion was any revision shoulder arthroscopy. All arthroscopic rotator cuff repairs (ARCR) were grouped together and all other nonarthroscopic rotator cuff repair surgeries (non-ARCR) were grouped together.

Results

In total, 118 shoulder arthroscopies had data collected prospectively at the time of surgery: 90 primary shoulder arthroscopies met the inclusion criteria; 28 were excluded because they were revision surgeries. There were 42 patients in the ARCR group (Group 1). Six of these were partial tears, and 36 were full-thickness tears. There were 48 patients in the non-ARCR group (Group 2). The non-ARCR Group 2 served as an anatomic baseline for ARCR Group 1. In all 90 shoulders, the rotator cable and anterior cable were identified. Group 1 (ARCR) incidence of anterior cable tears with abnormal position was 71.4% compared to 2.1% in group 2 (non-ARCR) (P < .001) Group 1 (ARCR) incidence of anterior cable tears with normal anterior cable position (n = 12) was compared to abnormal anterior cable position (n = 30). Injury to the anterior footprint capsular and tendon zones were compared. Normal anterior cable position correlated with no or low-grade injury to anterior footprint capsular zone. (Nimura zone C1). Abnormal anterior cable displacement graded as moderate (n = 20) and severe (n = 10) were compared for injury to the anterior footprint. Moderate displacement correlated with complete or high grade injury to C1 in 85% and complete injury to R1 in 45% (P < .001 and .049). In severe displacement complete C1 injury was 100%, and complete R1 injury was 100% (P < .001 and .001).

Conclusions

Anterior cable tears are universally identified in ARCR. Three patterns of medial displacement severity correlated with injury to a crucial insertion zone (C1) at the anterior footprint. The degree of anterior cable disruption at the anterior footprint and displacement was commonly disproportionately greater than the injury to the supraspinatus.

Level of Evidence

Level III, diagnostic study.

Arthroscopic Bursa-Augmented Rotator Cuff Repair: A Vasculature-preserving Technique for Subacromial Bursal Harvest and Tendon Augmentation

Rotator cuff repairs are associated with suboptimal outcomes and possibly greater incidence of retears if the biological healing environment is compromised. Strategies to optimize tendon-bone healing include the use of bioinductive scaffolds and regenerative stem cell therapy. The subacromial bursa has been shown to have significant pluripotent stem cell potency for tendon healing and has the advantage of easy accessibility and no added cost. However, a reproducible surgical technique for bursal mobilization, harvest, and vascularity preservation has not been described. We describe our technique for vasculature-preserving bursal mobilization and harvest of the entire posterosuperior and lateral subacromial bursa, and its use in rotator cuff repair augmentation is presented. The technique involves mobilization of the bursa as a continuous layer by maintain its medial and lateral vascularity. The bursa is advanced laterally, and the "vascular bursal duvet" and cuff tendons are repaired together as a tendon-bursa unit.

Endoscopic Implantation of Bioinductive Patch for Chronic Partial Retearing After Hamstring Repair

Proximal hamstring tendon avulsions are a relatively rare type of hamstring injury associated with persistent morbidity, including pain, weakness, and functional limitations. Open or endoscopic surgical repair is the standard treatment for complete tendon avulsions or partial tears that remain symptomatic despite conservative management in relatively young, healthy, and active patients. However, complications known to occur include retearing of the hamstring, infection, nerve injury, inability to return to work or sport, subjective persistent weakness, and subjective persistent pain. In the case of persistent pain where the repair is partially retorn, a careful history, physical examination, and scrutiny of radiologic studies can help guide management. We describe a technique for using revision endoscopy and augmentation with a bovine bioinductive patch in a case of chronic persistently painful partial retear after a proximal hamstring repair.

Patch augmentation surgery for rotator cuff repair: the PARCS mixed-methods feasibility study

BACKGROUND

A rotator cuff tear is a common, disabling shoulder problem. Symptoms may include pain, weakness, lack of shoulder mobility and sleep disturbance. Many patients require surgery to repair the tear; however, there is a high failure rate. There is a need to improve the outcome of rotator cuff surgery, and the use of patch augmentation (on-lay or bridging) to provide support to the healing process and improve patient outcomes holds promise. Patches have been made using different materials (e.g. human/animal skin or tissue and synthetic materials) and processes (e.g. woven or mesh).

OBJECTIVES

The aim of the Patch Augmented Rotator Cuff Surgery (PARCS) feasibility study was to determine the design of a definitive randomised controlled trial assessing the clinical effectiveness and cost-effectiveness of a patch to augment surgical repair of the rotator cuff that is both acceptable to stakeholders and feasible.

DESIGN

A mixed-methods feasibility study of a randomised controlled trial.

DATA SOURCES

MEDLINE, EMBASE and the Cochrane Library databases were searched between April 2006 and August 2018.

METHODS

The project involved six stages: a systematic review of clinical evidence, a survey of the British Elbow and Shoulder Society's surgical membership, a survey of surgeon triallists, focus groups and interviews with stakeholders, a two-round Delphi study administered via online questionnaires and a 2-day consensus meeting. The various stakeholders (including patients, surgeons and industry representatives) were involved in stages 2-6.

RESULTS

The systematic review comprised 52 studies; only 15 were comparative and, of these, 11 were observational (search conducted in August 2018). These studies were typically small (median number of participants 26, range 5-152 participants). There was some evidence to support the use of patches, although most comparative studies were at a serious risk of bias. Little to no published clinical evidence was available for a number of patches in clinical use. The membership survey of British Elbow and Shoulder surgeons [105 (21%) responses received] identified a variety of patches in use. Twenty-four surgeons (77%) completed the triallist survey relating to trial design. Four focus groups were conducted, involving 24 stakeholders. Differing views were held on a number of aspects of trial design, including the appropriate patient population (e.g. patient age) to participate. Agreement on the key research questions and the outline of two potential randomised controlled trials were achieved through the Delphi study [29 (67%)] and the consensus meeting that 22 participants attended.

LIMITATIONS

The main limitation was that the findings were influenced by the participants, who are not necessarily representative of the views of the relevant stakeholder groups.

CONCLUSION

The need for further clinical studies was clear, particularly given the range and number of different patches available.

FUTURE WORK

Randomised comparisons of on-lay patch use for completed rotator cuff repairs and bridging patch use for partial rotator cuff repairs were identified as areas for further research. The value of an observational study to assess safety concerns of patch use was also highlighted. These elements are included in the trial designs proposed in this study.

STUDY REGISTRATION

The systematic review is registered as PROSPERO CRD42017057908.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 13. See the NIHR Journals Library website for further project information.

Retear rates and clinical outcomes at 1 year after repair of full-thickness rotator cuff tears augmented with a bioinductive collagen implant: a prospective multicenter study

Background

Biologic technologies can potentially augment existing arthroscopic rotator cuff repair to improve retear rates and postoperative outcomes. The purpose of this study was to evaluate healing rates and clinical outcomes of full-thickness rotator cuff repairs augmented with a bioinductive bovine collagen implant.

Methods

In this prospective multicenter study, investigators enrolled 115 patients (mean age, 60.4 years) with full-thickness rotator cuff tears. There were 66 (57.4%) medium (1-3 cm) tears and 49 (42.6%) large (3-5 cm) tears. Eligible patients consisted of those ≥21 years of age with chronic shoulder pain lasting longer than 3 months and unresponsive to conservative therapy. Patients underwent single- or double-row repair augmented with a bioinductive bovine collagen implant. At the baseline, 3 months, and 1 year, magnetic resonance imaging was performed and patients were assessed for American Shoulder and Elbow Surgeons (ASES) Shoulder Score and Constant-Murley Score (CMS). The primary failure end point was retear, classified as any new full-thickness defect observed on magnetic resonance imaging.

Results

There were 13 retears (11.3%) at 3 months, with an additional 6 (19 total [16.5%]) found at 1 year. In large tears, double-row repair had a significantly lower rate of retear at 3 months (P = .0004) and 1 year (P = .0001) compared with single-row repair. ASES and CMS scores significantly improved between the baseline and 1 year for medium and large tears. At 1 year, the minimally clinically important difference for ASES and CMS was met by 91.7% (95% CI: 84.9-96.1) and 86.4% (95% CI: 78.2-92.4) of patients, respectively. Patients without retear and those <65 years of age had significantly better CMS scores at 1 year when compared with those with retear and those ≥65 years (P < .05). There was no statistically significant difference in outcomes based on treatment of the biceps tendon. Of 9 reported reoperations in the operative shoulder, only 2 were considered potentially related to the collagen implant.

Conclusion

Interim results from this prospective study indicate a favorable rate of retear relative to the literature and improvement in clinical function at 1 year after adjunctive treatment with the study implant augmenting standard arthroscopic repair techniques.

Use of implantable meshes for augmented rotator cuff repair: a systematic review and meta-analysis

OBJECTIVE

To appraise studies reporting on clinical effectiveness and safety of surgical meshes used to augment rotator cuff repairs (RCRs).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase and Cochrane databases were searched between April 2006 and April 2020.

ELIGIBILITY CRITERIA

All studies evaluating adults (≥18 years) undergoing RCR were considered. There were no language restrictions.

DATA EXTRACTION AND SYNTHESIS

Screening, data extraction and quality appraisal were conducted by two independent reviewers. Meta-analysis was conducted using a random-effects models if ≥2 comparative studies reported the same outcome measure. Risk of bias assessment was undertaken for randomised (RoB2, Cochrane) and comparative studies (ROBINS-I, Cochrane).

RESULTS

We included 60 studies, consisting of 7 randomised controlled trials, 13 observational comparative studies and 40 observational case series. All comparative studies reported on shoulder-specific functional outcome scores, 18 on the radiographic occurrence of re-tear and 14 on pain score metrics. All studies contained some risk of bias.Compared with non-augmented repair, a small improvement in shoulder-specific function or pain scores was observed for synthetic patches with a mean improvement of 6.7 points on the University of California Los Angles (UCLA) shoulder score (95% CI 0.1 to 13.4) and 0.46 point reduction on the Visual Analogue Scale (95% CI -0.74 to -0.17), respectively. A reduced likelihood of radiologically observed re-tear was observed for synthetic (risk ratio (RR) 0.41, 95% CI 0.27 to 0.61) and allograft (RR 0.34, 95% CI 0.18 to 0.65) patches. A total of 49 studies reported on the occurrence of complications. Slightly higher crude complication rates were observed following patch-augmented repair (2.1%) than standard repair (1.6%).

CONCLUSIONS

While several studies suggest a decreased failure rate and small improvements in shoulder function and pain following augmented RCR, a paucity of rigorous clinical evaluation, for both effectiveness and safety, prevents firm recommendations.

PROSPERO REGISTRATION NUMBER

CRD42017057908.

Comparison of biologic scaffolds for augmentation of partial rotator cuff tears in a canine model

BACKGROUND

This study was designed to test the hypothesis that biologic scaffold augmentation of articular-sided partial-thickness supraspinatus tendon tears would be associated with superior functional, imaging, biomechanical, and histologic properties compared with untreated tears in a preclinical canine model.

METHODS

With Institutional Animal Care and Use Committee approval, dogs (n = 16) underwent half-thickness resection of the articular portion of the supraspinatus tendon (SST). Defects were treated by débridement (DB) (n = 8) or scaffold augmentation on the bursal side using amnion matrix cord scaffold (AM) (n = 8), decellularized human dermal allograft (AF) (n = 8), or bovine collagen patch (RMP) (n = 8). Control dogs (n = 4; 8 normal shoulders) were included. Assessments included lameness, function, comfortable shoulder range of motion (CROM), pain, ultrasonography, magnetic resonance imaging (MRI), arthroscopy, gross examination, biomechanical testing, and histopathology.

RESULTS

At 3 months, CROM was significantly lower and pain significantly higher in DB compared with all other groups. At 6 months, CROM was significantly lower and pain significantly higher in RMP compared with AM and AF, and AM and AF showed significantly less thickening than DB and RMP. AF had the least severe MRI pathology and AM had significantly less MRI pathology than DB. AF SSTs and biceps tendons showed the least severe histopathology, and AM SSTs showed significantly less histopathology than DB and RMP SSTs.

CONCLUSION

Biologic scaffolds can be effective in augmenting healing of articular-sided partial-thickness SST tears when compared with débridement in a preclinical canine model. Decellularized human dermal allograft and amnion matrix cord may have advantages over the bovine collagen patch for use in this indication.

Arthroscopic Hip Capsular Plication With Augmentation Using a Bioinductive Collagen Implant

With advancements in arthroscopic techniques and instrumentation, hip arthroscopy has become an increasingly used technique to treat soft-tissue and osseous pathologies about the hip. Patient predisposition to labral and capsular injuries can present as femoroacetabular impingement or hip dysplasia, sometimes in combination. Capsular management continues to be a topic of debate, with capsular repair becoming the standard of care in most cases. Furthermore, in cases of borderline dysplasia and microinstability, considerations for not only capsular repair but with plication has shown significant clinical success. Although plication in this setting has shown promise, given a 20% failure rate, we suggest capsular augmentation to bolster the repair. We present a technique of capsular augmentation using a bioinductive collagen implant (Smith & Nephew) to improve the capsular integrity following repair and plication. The benefits of this implant are easy delivery through standard arthroscopic portals and secure fixation to the capsular tissue. These implants have a proven track record in the shoulder and serve as a scaffold for improved tissue quality, and their application in hip arthroscopy has potential by increasing the integrity of the capsular repair. Future studies are needed to address the clinical outcomes of this technique.

Bioaugmentation in the surgical treatment of anterior cruciate ligament injuries: A review of current concepts and emerging techniques

Injuries involving the anterior cruciate ligament are among the most common athletic injuries, and are the most common involving the knee. The anterior cruciate ligament is a key translational and rotational stabilizer of the knee joint during pivoting and cutting activities. Traditionally, surgical intervention in the form of anterior cruciate ligament reconstruction has been recommended for those who sustain an anterior cruciate ligament rupture and wish to remain active and return to sport. The intra-articular environment of the anterior cruciate ligament makes achieving successful healing following repair challenging. Historically, results following repair were poor, and anterior cruciate ligament reconstruction emerged as the gold-standard for treatment. While earlier literature reported high rates of return to play, the results of more recent studies with longer follow-up have suggested that anterior cruciate ligament reconstruction may not be as successful as once thought: fewer athletes are able to return to sport at their preinjury level, and many still go on to develop osteoarthritis of the knee at a relatively younger age. The four principles of tissue engineering (cells, growth factors, scaffolds, and mechanical stimuli) combined in various methods of bioaugmentation have been increasingly explored in an effort to improve outcomes following surgical treatment of anterior cruciate ligament injuries. Newer technologies have also led to the re-emergence of anterior cruciate ligament repair as an option for select patients. The different biological challenges associated with anterior cruciate ligament repair and reconstruction each present unique opportunities for targeted bioaugmentation strategies that may eventually lead to better outcomes with better return-to-play rates and fewer revisions.

Revision Hip Capsular Repair and Augmentation With a Bioinductive Implant After a Post-arthroscopy Hip Subluxation Event

In the past decade, the number of hip arthroscopy procedures has exponentially increased, primarily for the treatment of femoroacetabular impingement syndrome and labral lesions. As the techniques have evolved, so has the acknowledgment of the potential complications, including iatrogenic instability that may result from soft-tissue laxity, subtle dysplastic morphologies, or residual defects from capsulotomies in which the capsular closure is insufficient. In most cases, direct capsular repair or plication can be performed at the conclusion of the procedure; however, larger defects, poor-quality tissue, or cases of gross ligamentous laxity may require reconstruction or augmentation. In such instances, several options exist. The purpose of this technical note is to describe a capsular repair augmentation with a bioinductive implant during revision hip arthroscopy.

Editorial Commentary: New Kid on the Block: Rotator Cuff Patch Augmentation Requires Rigorous Scrutiny

There is still plenty of room for improvement in surgical rotator cuff repair healing as well as in nonsurgical cases. Adding an implant or patch to improve results has been a subject of much discussion for a couple of decades. The main problem has been that the surgical procedures are so difficult, with added time and its effect, and therefore are controversial. Many surgeons are reluctant to go the surgical route. As we have advanced technically, we are at a turning point, with newer implants that can be easily augmented. Therefore, recently many surgeons have been using implants, and preliminary reports seem promising. New implants must withstand vigorous challenges, and future extensive and long-term studies can enable improved implants using human tissue.

Patient-Reported Outcomes After Use of a Bioabsorbable Collagen Implant to Treat Partial and Full-Thickness Rotator Cuff Tears

PURPOSE

To collect outcomes data on patients treated with a bioinductive collagen implant designed to induce rotator cuff healing in partial- and full-thickness cuff tears and to assess the safety and efficacy of the device.

METHODS

Fifteen surgeons in 15 centers in the United States enrolled patients between April 2016 and August 2017 and collected standardized outcomes data. Patients 21 years of age and older, able to read and speak English, and with partial- or full-thickness tears of the rotator cuff documented by magnetic resonance imaging were included in the study. Patients were assessed preoperatively with visual analogue scale (VAS), single-assessment numeric evaluation (SANE), Veterans RAND 12-Item (VR-12), American Shoulder and Elbow Surgeons (ASES), and Western Ontario Rotator Cuff (WORC) outcomes measures. Postoperative assessment was made at 2, 6, and 12 weeks, 6 months, and 1 year. Patients underwent a standardized operative procedure with the implant. Patient demographics, comorbidities, tear types, and concomitant operative procedures were recorded.

RESULTS

Patients in both groups experienced statistically significant improvement in VAS, SANE, VR-12 PCS, ASES, and WORC scores (mean values 1.1, P < .001; 86.0, P < .001; 49.7, P < .001; 85.6, P < .001; and 84.4, P < .001 for partial tears and 1.2, P < .001; 80.7, P < .001; 45.7, P < .001; 83.8, P < .0001; and 80.1, P < .001 for full-thickness tears, respectively). For the partial tear group, average times for return to driving, work, and nonoverhead athletic activity were 14.6, 37.3, and 65.6 days, and for the full-thickness group, 24.5, 50.7, and 119.2 days, respectively. In the partial-thickness group, 84% and 83% of patients reported improvement in their VAS pain and ASES scores, respectively, that met or exceeded each measure's minimal clinically important difference. In the full-thickness group, 72% and 77% of the patients met or exceeded the minimal clinically important differences for VAS pain and ASES, respectively.

CONCLUSION

Outcomes after repair of partial- and full-thickness rotator cuff tears using a bioinductive implant show safety and efficacy at 1-year follow-up.

LEVEL OF EVIDENCE

Retrospective case series, level IV evidence.