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

Bioinductive patch as an augmentation for rotator cuff repair, a systematic review and meta-analysis

BACKGROUND

Rotator cuff tears are a prevalent cause of shoulder pain and dysfunction. For those who fail initial conservative treatment, operative intervention can be pursued. A significant and common complication after rotator cuff repair (RCR) is retearing or nonhealing. Numerous augmentations to traditional suture RCR have been studied. Of these, the Smith + Nephew Regeneten bioinductive collagen patch has had promising initial results; however, analytic data for its use are lacking, and there is no meta-analysis comparing the available data to historical RCR outcomes.

METHODS

A PRISMA-guided literature search was conducted using Ovid MEDLINE, PubMED, Cochrane, and ClinicalTrials.gov. Thirteen studies met inclusion and exclusion criteria. Only clinical trials on full and partial-thickness tears were included. American Shoulder and Elbow Surgeon score, Constant-Murley Score, the visual analog scale for pain, the minimal clinically important difference (MCID), tendon thickness, and complication rates were primary outcomes of interest. A meta-analysis was performed to determine the overall complication and retear rate from the included studies.

RESULTS

American Shoulder and Elbow Surgeon score, Constant-Murley Score, and visual analog scale for pain improved significantly in all studies that reported them, and most patients achieved MCID. Patient-reported outcome measure improvements were similar to historical improvements in standard RCR, and a similar proportion of patients achieved MCID after standard repair. Tendon thickness improved significantly and to a similar degree as standard RCR. Overall retear rate after full thickness RCR augmented with the bioinductive patch was 8.3%. For partial thickness RCR, total retear rate was of 1.1% across all patients. The overall complication rate with the bioinductive patch was 15.5% across all full-thickness RCR studies and 16.2% in partial thickness RCR. We found overall retear rate to be lower after augmentation with the bioinductive patch compared to traditional repair; however, the overall complication rate was similar for full-thickness tears and higher for partial-thickness tears. Lastly, adverse reactions to the bioinductive patch were noted at 0.2%.

CONCLUSIONS

The bioinductive collagen patch appears to be a safe augmentation for rotator cuff repair. Patients are likely to experience significant subjective improvement in patient-reported outcome measures and significant increases in tendon thickness. Retear rate has been a concern after RCR for decades, and the bioinductive patch may help mitigate this risk. There is lack of case-control studies comparing the bioinductive patch to traditional suture RCR. Such data are needed to better determine the role of the bioinductive patch in the treatment of full and partial-thickness rotator cuff repairs.

Bioinductive Collagen Implant Has Potential to Improve Rotator Cuff Healing: A Systematic Review

PURPOSE

To systematically review the literature to evaluate the clinical studies on bioinductive collagen implant (BCI) for the treatment of rotator cuff tears.

METHODS

A literature search of MEDLINE, Embase, and the Cochrane Library was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Clinical studies reporting BCI for rotator cuff tears were included. Quantitive and qualitative data were evaluated.

RESULTS

A total of 21 studies were included. In patients with full-thickness tears, 7 of the 8 studies with pre- to postoperative American Shoulder and Elbow Surgeons (ASES) scores demonstrated statistically significant improvements in mean pre- to postoperative ASES scores, with 75% to 100% of patients meeting the minimal clinically important difference. In those with partial-thickness tears, 7 of the 8 studies with pre- to postoperative ASES scores demonstrated statistically significant improvements in mean pre- to postoperative ASES scores, with 54.4% to 100% of patients meeting the minimal clinically important difference. For studies that quantified percent increases in tendon thickness, the reported increases ranged from 13% to 44% in full-thickness tears and 14% to 60% in partial-thickness tears. Six studies evaluated rotator cuff retears after BCI treatment in the full-thickness cohort, with rates reported ranging from 0% to 9%. Five studies evaluated rotator cuff retears after BCI treatment in the partial-thickness cohort, with rates reported ranging from 0% to 18%. Two of the included studies found that BCI was cost-effective due to the increased tendon healing, with cost savings of $5,338 to $13,061 per healed rotator cuff tendon.

CONCLUSIONS

The literature on rotator cuff tear augmentation with BCI has shown consistently reported good results. Additionally, there was evidence of low retear rates and consistently improved tendon thickness with BCI, with 2 randomized controlled trials showing improved tendon healing with BCI. However, there appears to be a higher rate of adhesive capsulitis reported.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I, III, and IV studies.

The bioinductive collagen implant yields positive histological, clinical and MRI outcomes in the management of rotator cuff tears: A systematic review

PURPOSE

The aim of this study is to report and discuss the outcomes of clinical, histological and animal studies exploring the application of bio-inductive collagen implants (BCIs) to partial and full-thickness rotator cuff tears (PT- and FT-RCTs) in addition to reporting on cost-related factors.

METHODS

Review of literature was performed using the PRISMA guidelines. A systematic electronic literature search was conducted using the CENTRAL, CINAHL, Cochrane Library, EBSCOhost, EMBASE and Google Scholar bibliographic databases. Microsoft Excel was used to create tables onto which extracted data were recorded. Tables were organized based on the research statement formulated using the PICO approach. No statistical analysis was performed.

RESULTS

Nine studies evaluated clinical and MRI outcomes of BCI augmentation for FT-RCTs, seven evaluated similar outcomes when applied to PT-RCTs, two additional studies were case reports and three studies assessed application to FT- and PT-RCTs without stratification of results, one of which also reported on histological data. Two studies reported on histological data alone, and finally, two reported on healthcare costs. BCI augmentation, alone and combined with rotator cuff repair (RCR), displays generally good histological, postoperative clinical and MRI outcomes for PT- and FT-RCT treatment. Recent economic analyses seem to be in favour of the use of this procedure, when selected and applied for appropriate patient populations.

CONCLUSION

Several studies have shown promising results of BCI application to PT- and FT-RCTs, both concomitantly and independently from RCR. Investigations report promising histological characteristics, improved clinical outcomes, increased tendon thickness, reduced defect size and lower re-tear rates.

LEVEL OF EVIDENCE

Level IV.

No Short-term Clinical Benefit to Bovine Collagen Implant Augmentation in Primary Rotator Cuff Repair: A Matched Retrospective Study

BACKGROUND

Bovine bioinductive collagen implants (herein, "bovine collagen implant") can be used to augment rotator cuff repair. Concern exists that these bovine collagen implants may not yield clinical benefits and may actually increase postoperative stiffness and the need for reoperation.

QUESTIONS/PURPOSES

Among patients who underwent primary rotator cuff repair with or without a bovine collagen implant, we asked: (1) Did the proportion of patients undergoing reoperation for postoperative stiffness and inflammation differ between the bovine collagen implant and control groups? (2) Did short-term patient-reported outcomes differ between the two groups? (3) Did the proportion of patients receiving postoperative methylprednisolone prescriptions and corticosteroid injections differ between the two groups?

METHODS

We performed a retrospective, matched, comparative study of patients 18 years and older with minimum 2-year follow-up who underwent primary arthroscopic repair of partial or full-thickness rotator cuff tears diagnosed by MRI. All procedures were performed by one surgeonbetween February 2016 and December 2021. During the period in question, this surgeon broadly offered the bovine collagen implant to all patients who underwent rotator cuff repair and who (1) consented to xenograft use and (2) had surgery at a facility where the bovine collagen implant was available. The bovine collagen implant was used in rotator cuff tears of all sizes per the manufacturer's instructions. A total of 312 patients were considered for this study (243 control, 69 implant). Minimum 2-year clinical follow-up data were available for 83% (201 of 243) of patients in the control group and 90% (62 of 69) of patients in the bovine collagen implant group. After we applied the exclusion criteria, 163 control and 47 implant group patients remained and were eligible for matching. Propensity score matching was conducted to balance cohorts by age, gender, race (Black, White, other), ethnicity (Hispanic, non-Hispanic), health insurance status, Area Deprivation Index, BMI, American Society of Anesthesiologists physical status classification, diabetes, smoking, rotator cuff tear size, concomitant surgical procedures, preoperative American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), VAS score for pain, and shoulder ROM. We included 141 patients (47 in the implant group and 94 in the control group) after matching. Patients were categorized according to whether they received the bovine collagen implant. Before matching, the control cohort was older (mean ± SD 57 ± 10 years versus 52 ± 11 years; p = 0.004), more likely to be White (58% versus 23%; p < 0.001), with a smaller proportion of concomitant distal clavicle excisions (43% versus 21%; p = 0.003), and a smaller proportion of "other" concomitant procedures (17% versus 6%; p = 0.011) compared with the implant cohort. After matching, the cohorts were well matched in all demographic variables. The primary study outcome was reoperation for inflammation and stiffness, defined as a failure of nonoperative treatment for a minimum of 9 months, including physical therapy, NSAIDs, at least one course of oral methylprednisolone, and at least one cortisone injection (reoperations for traumatic retears were excluded). Secondary outcomes were patient-reported outcomes (SSV, ASES score, and VAS score for pain), receipt of methylprednisolone prescriptions, and receipt of corticosteroid injections. Chi-square, Fisher exact tests, and independent-samples t-tests were used to assess relationships between treatment group and study outcomes.

RESULTS

A greater proportion of patients in the bovine collagen implant group (9% [4 of 47]) underwent reoperation for inflammation and stiffness than in the control group (0% [0 of 94; p = 0.01]). At minimum 2-year follow-up, the cohorts did not differ by ASES score (mean ± SD 81 ± 24 implant versus 85 ±19 control; p = 0.24), SSV (79 ± 24 implant versus 85 ± 18 control; p = 0.30), or VAS score for pain (2.0 ± 2.9 implant versus 1.5 ± 2.3 control; p = 0.11). The cohorts did not differ in the proportion who received postoperative corticosteroid injections (15% implant versus 11% control; p = 0.46) or methylprednisolone prescriptions (49% implant versus 37% control; p = 0.18).

CONCLUSION

At minimum 2-year follow-up, patients undergoing primary arthroscopic rotator cuff repair with bovine collagen implant augmentation had a greater proportion of reoperation due to inflammation and stiffness compared with patients who did not receive the implant. Furthermore, the implant offered no benefit in patient-reported outcomes or need for postoperative corticosteroid injections or methylprednisolone prescriptions. Because of the lack of clinical benefit and potential increase in postoperative complications, we recommend against the use of these bovine collagen implants unless high-quality randomized controlled trials are able to demonstrate their clinical effectiveness, cost-effectiveness, and overall safety.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Arthroscopic management of isolated partial-thickness rotator cuff tears

PURPOSE

The aim of the present study is to provide a comprehensive review on the surgical outcomes following arthroscopic treatments of partial-thickness rotator cuff tears (PT-RCTs) and to compare the postoperative American Shoulder and Elbow Surgeons (ASES) score following in situ transtendon repair and tear completion, followed by repair.

METHODS

Medline, EMBASE, Scopus, CINAHL and CENTRAL bibliographic databases were searched. Papers including patients with PT-RCTs of any grade who underwent treatment using debridement, in situ transtendon repair, tear completion and repair or bioinductive collagen implants were reviewed. Primary PT-RCTs were the sole indication for surgery. Primary postoperative outcomes assessed included the ASES score, the Absolute Constant-Murley score, the Simple Shoulder Test, the Visual Analogue Scale, the University of California-Los Angeles Shoulder Scale, the Western Ontario Rotator Cuff Score, range of motion, complications and revisions. A meta-analysis of comparative studies compared the postoperative ASES score between patients treated with in situ transtendon repair versus tear completion repair.

RESULTS

Twenty-eight studies were included. The ASES score was reported by four comparative studies with contrasting results. The heterogeneity was high (I2 = 86%), and effect sizes ranged from -0.49 in favour of the tear completion and repair technique to an effect size of +1.07 favouring in situ transtendon repair. The overall effect size of 0.02 suggests an equivalence between the two techniques in terms of the ASES score. Two studies with a total sample size of 111 patients reported on debridement, and four studies with a total sample size of 155 patients reported on bioinductive collagen implants.

CONCLUSION

Debridement alone is suitable for Ellman grades I-II PT-RCTs. In situ transtendon and tear completion repair techniques yield similar postoperative outcomes. Bioinductive collagen implants hold promise but lack long-term efficacy data. High-quality comparative studies are needed to determine the best treatment for PT-RCTs.

LEVEL OF EVIDENCE

Level IV.

Biologics in rotator cuff repair

Rotator cuff tears are common in middle-aged and elderly patients. Despite advances in the surgical repair of rotator cuff tears, the rates of recurrent tear remain high. This may be due to the complexity of the tendons of the rotator cuff, which contributes to an inherently hostile healing environment. During the past 20 years, there has been an increased interest in the use of biologics to complement the healing environment in the shoulder, in order to improve rotator cuff healing and reduce the rate of recurrent tears. The aim of this review is to provide a summary of the current evidence for the use of forms of biological augmentation when repairing rotator cuff tears.

An isolated bioinductive repair vs sutured repair for full-thickness rotator cuff tears: 2-year results of a double blinded, randomized controlled trial

BACKGROUND

Partial-thickness rotator cuff tears treated with an isolated bioinductive repair (IBR) in lieu of a completion-and-repair have shown complete healing. This treatment option is afforded by the remaining tendon's structural integrity, which is similar to that present in small/medium full-thickness tears (FTTs) when the rotator cable remains intact. This randomized controlled trial (RCT) investigated whether an IBR for small/medium full-thickness tears resulted in superior healing and patient-reported outcomes (PROs) compared with a sutured repair.

METHODS

This prospective, double blinded (patients and outcome assessors), single-center randomized controlled trial enrolled patients ≥18 years with a small/medium (≤2.5 cm) full thickness supraspinatus tear and intact rotator cable. Patients were randomized and blinded to arthroscopic transosseous-equivalent repair (control, n = 30) or IBR (n = 30). The primary outcome was tendon quality on biopsy at 6 months. Secondary outcomes were PROs (American Shoulder and Elbow Surgeons [ASES], Constant-Murley Shoulder [CMS], and pain visual analogue scale scores) and tendon thickness and healing measured via MRI at 6, 12, and 24 months; satisfaction at 12 and 24 months; and time to return to work.

RESULTS

Baseline demographic, tear, and surgical characteristics were comparable between the groups (IBR: mean age, 54.2 years, 14 male; control: mean age, 56.4 years, 16 male). Measured via a 6-month biopsy, highly organized, parallel bundles of collagen, without inflammation, were present in all IBR patients, whereas poorly organized, nonparallel collagen fibers were present in 24/30 (80%) of control patients (P < .0001), with 28/30 having minimal to mild inflammation. The increase in tendon thickness measured via MRI at 6 months from baseline was greater in the IBR group (2.0 mm) than in the control group (0.8 mm) (P < .0001). All IBR patients had 100% healing on MRI at 12 and 24 months. Compared with the control group, the IBR group had higher American Shoulder and Elbow Surgeons and Constant-Murley Shoulder scores at each evaluation, less pain at 6 and 12 months, and greater satisfaction at 12 and 24 months (P < .0003). The IBR group returned to work significantly faster (median 90 days [IQR, 25] vs. median 163.5 days [IQR, 24]; P < .0001) than the control group.

CONCLUSION

Compared with a sutured repair, the IBR treatment resulted in superior tendon quality, patient outcomes, satisfaction, and return to work. The IBR enabled a robust healing response evident through MRI and biopsy evaluation, demonstrating superior tendon quality and healing.

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.

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.

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.

Can the Single Assessment Numeric Evaluation be used as a stand-alone subjective outcome instrument in patients undergoing rotator cuff repair?

BACKGROUND/HYPOTHESIS

There is no consensus to which patient-determined shoulder outcome scores should be considered when analyzing patient outcomes. Use of multiple patient-determined outcomes may be redundant and cause increased responder burden. The Single Assessment Numeric (SANE) has not been widely accepted as a stand-alone shoulder-specific outcome measure. The hypothesis was that SANE will correlate with and be comparable in responsiveness to other subjective outcome measures that have been used in a stand-alone fashion in patients undergoing rotator cuff repair (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], Western Ontario Rotator Cuff Index [WORC], and the Simple Shoulder Test [SST]). In addition, the SANE will be more relevant to each patient compared to the ASES, further supporting its use as a stand-alone shoulder-specific outcomes measure.

METHODS

A retrospective review of a database of patients undergoing rotator cuff repair was reviewed where the SANE was recorded with the ASES, WORC, and/or SST. Correlations were determined using the Pearson coefficient. Subgroup analysis was performed to determine if correlations differed in (1) preoperative and (2) postoperative outcome determinations. Responsiveness was determined by calculating the standardized response mean (SRM) and the effect size (ES) of all scores. Relevance and precision of the SANE and ASES were examined using 150 consecutive patients to determine the number of questions in each score that were not answered.

RESULTS

Correlation was excellent for the SANE and the ASES (n = 1838, r = 0.81, P < .0001), the WORC (n = 1793, r = 0.82, P < .0001), and the SST (n = 1836, r = 0.76, P < .0001). Correlation of preoperative scores was moderate and postoperative scores were excellent when comparing the SANE with all 3 scores. All scores were highly responsive, with the SRM of the SANE = 2.1, ASES = 2.2, WORC = 2.4, and the SST = 1.8. The ES of the SANE = 2.4, ASES = 2.7, WORC = 3.0, and the SST = 2.1. One hundred percent of the SANE scores were answered completely compared with 57% (P < .0001) of the ASES, with significant variability found in the answers to the "work" and "score" questions.

CONCLUSION

In patients undergoing rotator cuff repair, the SANE highly correlated and has equivalent responsiveness with the WORC, ASES, and SST, which have been used as stand-alone shoulder-specific outcomes measures. The SANE may provide the same information as the WORC, ASES, and SST regarding outcome with significant reduction in responder burden. This study supports that the SANE can be used as a subjective, stand-alone instrument for patients undergoing rotator cuff repair.

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.