Use of biologics in rotator cuff disorders: Current concept review

Multiaxial filament winding of biopolymer microfibers with a collagen resin binder for orthobiologic medical device biomanufacturing

Multiaxial filament winding is an additive manufacturing technique used extensively in large industrial and military manufacturing yet unexplored for biomedical uses. This study adapts filament winding to biomanufacture scalable, strong, three-dimensional microfiber (3DMF) medical device implants for potential orthopedic applications. Polylactide microfiber filaments were wound through a collagen 'resin' bath to create organized, stable orthobiologic implants, which are sized for common ligament (e.g. anterior cruciate ligament) and tendon (e.g. rotator cuff) injuries and can be manufactured at industrial scale using a small footprint, economical, high-output benchtop system. Ethylene oxide or electron beam sterilized 3DMF samples were analyzed by scanning electron microscopy (SEM), underwent ASTM1635-based degradation testing, tensile testing, ISO 10993-based cytocompatibility, and biocompatibility testing, quantified for human platelet-rich plasma (PRP) absorption kinetics, and examined for adhesion of bioceramics and lyophilized collagen after coating. 3DMF implants had consistent fiber size and high alignment by SEM. Negligible mass and strength loss were noted over 4 months in culture. 3DMF implants initially exceeded 1000 N hydrated tensile strength and retained over 70% strength through 4 months in culture, significantly stronger than conventionally produced implants made by fused fiber deposition 3D printing. 3DMF implants absorbed over 3xtheir weight in PRP within 5 min, were cytocompatible and biocompatible in vivo in rabbits, and could readily bind tricalcium phosphate and calcium carbonate coatings discretely on implant ends for further orthobiologic material functionalization. The additive manufacturing process further enabled engineering implants with suture-shuttling passages for facile arthroscopic surgical delivery. This accessible, facile, economical, and rapid microfiber manufacturing platform presents a new method to engineer high-strength, flexible, low-cost, bio-based implants for orthopedic and extended medical device applications.

Comparative effect of skeletal stem cells versus bone marrow mesenchymal stem cells on rotator cuff tendon-bone healing

Background

Bone marrow mesenchymal stem cells (BMSCs) have immense potential in applications for the enhancement of tendon-bone (T-B) healing. Recently, it has been well-reported that skeletal stem cells (SSCs) could induce bone and cartilage regeneration. Therefore, SSCs represent a promising choice for cell-based therapies to improve T-B healing. In this study, we aimed to compare the therapeutic potential of SSCs and BMSCs for tendon-bone healing.

Methods

SSCs and BMSCs were isolated by flow cytometry, and their proliferation ability was measured by CCK-8 assay. The osteogenic, chondrogenic, and adipogenic gene expression in cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). C57BL/6 mice underwent unilateral supraspinatus tendon detachment and repair, and the mice were then randomly allocated to 4 groups: control group (tendon-bone interface without any treatment), hydrogel group (administration of blank hydrogel into the tendon-bone interface), hydrogel + BMSCs group (administration of hydrogel with BMSCs into the tendon-bone interface), and hydrogel + SSCs group (administration of hydrogel with SSCs into the tendon-bone interface). Histological staining, Micro-computed tomography (Micro-CT) scanning, biomechanical testing, and qRT-PCR were performed to assay T-B healing at 4 and 8 weeks after surgery.

Results

SSCs showed more cell proportion, exhibited stronger multiplication capacity, and expressed higher osteogenic and chondrogenic markers and lower adipogenic markers than BMSCs. In vivo assay, the SSCs group showed a better-maturated interface which was characterized by richer chondrocytes and more proteoglycan deposition, as well as more newly formed bone at the healing site and increased mechanical properties when compared to other there groups. qRT-PCR analysis revealed that the healing interface in the SSCs group expressed more transcription factors essential for osteogenesis and chondrogenesis than the interfaces in the other groups.

Conclusions

Overall, the results demonstrated the superior therapeutic potential of SSCs over BMSCs in tendon-bone healing.

The translational potential of this article

This current study provides valuable insights that SSCs may be a more effective cell therapy for enhancing T-B healing compared to BMSCs.

A Combined Treatment of BMP2 and Soluble VEGFR1 for the Enhancement of Tendon-Bone Healing by Regulating Injury-Activated Skeletal Stem Cell Lineage

BACKGROUND

Bone morphogenetic protein 2 (BMP2) is an appealing osteogenic and chondrogenic growth factor for promoting tendon-bone healing. Recently, it has been reported that soluble vascular endothelial growth factor (VEGF) receptor 1 (sVEGFR1) (a VEGF receptor antagonist) could enhance BMP2-induced bone repair and cartilage regeneration; thus, their combined application may represent a promising treatment to improve tendon-bone healing. Moreover, BMP2 could stimulate skeletal stem cell (SSC) expansion and formation, which is responsible for wounded tendon-bone interface repair. However, whether the codelivery of BMP2 and sVEGFR1 increases tendon enthesis injury-activated SSCs better than does BMP2 alone needs further research.

PURPOSE

To study the effect of BMP2 combined with sVEGFR1 on tendon-bone healing and injury-activated SSC lineage.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 128 C57BL/6 mice that underwent unilateral supraspinatus tendon detachment and repair were randomly assigned to 4 groups: (1) untreated control group; (2) hydrogel group, which received a local injection of the blank hydrogel at the injured site; (3) BMP2 group, which received an injection of hydrogel with BMP2; and (4) BMP2 with sVEGFR1 group, which received an injection of hydrogel with BMP2 and sVEGFR1. Histology, micro-computed tomography, and biomechanical tests were conducted to evaluate tendon-bone healing at 4 and 8 weeks after surgery. In addition, flow cytometry was performed to detect the proportion of SSCs and their downstream differentiated subtypes, including bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors within supraspinatus tendon enthesis at 1 week postoperatively.

RESULTS

The repaired interface in BMP2 with sVEGFR1 group showed a significantly improved collagen fiber continuity, increased fibrocartilage, greater newly formed bone, and elevated mechanical properties compared with the other 3 groups. There were more SSCs; bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors in the BMP2 with sVEGFR1 group than that in the other groups.

CONCLUSION

Our study suggests that the combined delivery of BMP2 and sVEGFR1 could promote tendon-bone healing and stimulate the expansion of SSCs and their downstream progeny within the injured tendon-bone interface.

CLINICAL RELEVANCE

Combining BMP2 with sVEGFR1 may be a good clinical treatment for wounded tendon enthesis healing.

Bone channeling in arthroscopic rotator cuff repair: a systematic review and meta-analysis of level I studies

BACKGROUND

There is ongoing controversy regarding the effect of bone channeling in arthroscopic rotator cuff repair. Since the most recent systematic reviews in 2019, several large high-level trials have been completed. This study assessed all available level I randomized controlled trials (RCTs) that compared arthroscopic rotator cuff repair with and without bone marrow channeling.

METHODS

A systematic search of the Ovid MEDLINE, Embase, and Cochrane Library databases was conducted through mid January 2023. Two reviewers performed screening of studies meeting the eligibility criteria: English-language RCTs in patients aged ≥18 years comparing arthroscopic rotator cuff repair of full-thickness tears with and without bone marrow channeling (channeling group and control group, respectively). Functional scores, pain, healing rates, and reoperations were reviewed using pooled analysis where appropriate. The methodologic quality of included studies was assessed using the Cochrane risk-of-bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

A total of 6 randomized studies (N = 593) met the inclusion criteria. Pooled analysis of all 6 studies showed no significant mean difference in function (1.32; 95% confidence interval [CI], -0.63 to 3.26), as measured by the Constant-Murley score. Retear rates were also not statistically different between groups (risk ratio, 0.99; 95% CI, 0.57 to 1.71), with pooled retear rates of 19.6% (48 of 245) with channeling and 19.8% (51 of 257) without. The other outcomes of interest were only available for analysis in a subset of studies. There were no standardized mean differences in pain (0.09; 95% CI, -0.18 to 0.36), and there were similar reoperation rates (risk ratio, 1.19; 95% CI, 0.43 to 3.34) in the channeling and control groups. For the included studies, the overall quality of evidence by outcome was judged to be moderate (function, pain, and reoperations) or low (retear rates), mainly owing to risk of bias (all outcomes) and inconsistency (retear rates).

CONCLUSION

The results of this study refute the findings of prior systematic reviews that showed that channeling reduces the retear rate when combined with arthroscopic rotator cuff repair. This meta-analysis of level I evidence, including recent larger RCTs, demonstrates that bone marrow stimulation in the setting of primary arthroscopic rotator cuff repair has no significant effect on functional outcomes, healing, pain, or reoperation rates.

Biomodulating healing after arthroscopic rotator cuff repair: the protocol of a randomised proof of concept trial (BIOHACK)

PURPOSE/INTRODUCTION

Over the last decades, there has been increasing interest in biological stimulation or bioaugmentation after rotator cuff repair. So far, there is no consensus on the appropriate composition of biologicals or which patients would benefit most, and moreover, these biologicals are often expensive. However, there are other, non-pharmacological strategies that are also believed to achieve biological stimulation. This randomised controlled trial evaluates the possible cumulative effect of pragmatic application of cryobiomodulation, photobiomodulation and electrobiomodulation-collectively called biomodulation-on the bone-to-tendon healing process after rotator cuff repair.

METHODS

In this randomised, controlled proof of concept study, 146 patients undergoing arthroscopic repair of a full thickness posterosuperior or anterosuperior rotator cuff tear will be 1:1 randomly assigned to either a control group or to the additional biomodulation protocol group. The adjuvant biomodulation protocol consists of seven self-applicable therapies and will be administered during the first 6 weeks after surgery. Primary outcome will be healing of the rotator cuff as evaluated by the Sugaya classification on MRI at 1-year postoperatively.

ETHICS AND DISSEMINATION

This study has been accepted by the National Ethical Review Board CPP Sud-Est IV in France and has been registered at Clinicaltrials.gov. The results of this study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04618484.

Collagen and platelet-rich plasma in partial-thickness rotator cuff injuries. Friends or only indifferent neighbours? Randomised controlled trial

BACKGROUND

Partial-thickness rotator cuff injuries (PTRCI) are the sum of degenerative, overload, and microtrauma processes. An external supply of collagen and platelet-rich plasma (PRP) could potentially counteract the deterioration of degenerative tendinopathy. This study aimed to compare the effectiveness of collagen with PRP, PRP alone, and collagen alone in the treatment of PTRCI.

METHODS

Ninety patients with PTRCI were randomised and treated with ultrasound-guided injections into the shoulder bursa every consecutive week: Group A - collagen with PRP (n = 30), Group B - collagen alone (n = 30), and Group C - PRP alone (n = 30). Primary outcomes were pain intensity measured in control points on a numeric rating scale (NRS), QuickDash, and EQ-5D-5L questionnaires at the initial assessment (IA) and control assessments after 6 (T1), 12 (T2), and 24 (T3) weeks, respectively.

RESULTS

No statistical differences were found between groups in primary outcomes, although there was a trend towards improvement in Groups A and C (opposite to Group B) between T2 and T3. The following parameters were also observed: rotator cuff discontinuity (n = 3, one case in each group) and rotator cuff regeneration (n = 22 in Group A, n = 20 in Group B, and n = 23 in Group C).

CONCLUSIONS

Combined therapy of collagen and PRP in PTRCI presents similar effectiveness to monotherapies with collagen or PRP.

TRIAL REGISTRATION

The study was prospectively registered on the NCT Trial Center (identification number: NCT04492748 ) on 30.07.2020.