Aims

Failure of healing is a well-known problem after repair of the rotator cuff. This study aimed to investigate if early repair of trauma-related full-thickness rotator cuff tears (FTRCTs) could prevent this failure.

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. Cite this article: Bone Joint J 2024;106-B(9):978–985

Introduction. It is an example of tendon to bone healing of rotator cuff tears. Low Level Laser Therapy (LLLT) is used in pain literature, pain palliation, tendinopathies, osteoarthritis treatment, implant osteointegration in jaw surgery, wound healing, fracture healing, tendon healing, nerve healing. But; there is not a study on tendon-bone healing. It is aimed to investigate the effects of tendon to bone healing with the rotator cuff experimental tear model. Material and Methods. 60 Wistor Albino Rat right shoulders were used in our project in four groups. Effectiveness of the study in each study group to increase and use the minimum number of animals that would be significant it was planned to use 15 (6 histology + 9 biomechanical) subjects. In our study, there are 4 groups in total. 1. Group 4. Week sacrified control group 2. Group 4. Week sacrificed LLLT group 3. Group 8. Week sacrified control group 4. Group is postoperative LLLT group. The 4 round SSP tendons have been cut with a full course. A total of eight sessions of biostimulation were performed with 24 j energy per session. Biomechanical tensile test and histopathological examination were performed on rats sacrificed at 4 and 8 weeks. In histological examination, cellularity at the repair site with hemotoxylin-eosin staining, extracellular matrix localization with Masson trichrome staining and fibrosis, TRAP (Tartrate Resistance Acid Phosphatase) and osteoclast activity, collagen fibril organization with picrochucine were evaluated. In immunohistological examination, proliferation activity was evaluated by CD-31 (Abcam, Cambridge, MA, USA) through vascular endothelial cells, Ki-67 (Tucson, AZ) and tendon proliferation index. Failure load for comparison of biomechanical stability between groups drawing will be done. Biomechanical pulling applications Linear pulling force over tendon It will be realized by applying. Last failure load (Newton), elongation (mm) and hardness values was recorded. Results. Two rats died in the postoperative first group and one rat died in the other groups. Six animals from each group were examined histopathologically. While the mean of stifness was higher in the patient who underwent LLLT at the 4th week biomechanically compared to the control group, there was no difference in the 8th week between the control group LLLT biomechanically. Histologically, the group with LLLT at 4 weeks showed increased fibroblastic activity and osteoclastic activity, but at 8 weeks there was no significant difference. Discussion. There are studies on the benefits of biostimulation with LLLT in fracture healing, implant integration, wound healing, tendon healing. Biostimulation experiments with LLLT for tendon healing were evaluated in rotator cuff healing as they were not available in literature. Especially early contributions were thought to be beneficial for postoperative rupture

Rotator cuff disease encompasses a spectrum from partial to full thickness tears. Despite being 2–3 times more common than full–thickness tears, effective non-operative treatment for partial thickness tears has remained elusive. Platelet enriched plasma (PRP) has been proposed to enhance rotator cuff healing by enhancing the natural healing cascade. However, its utility in rotator cuff disease remains controversial. The purpose of this study was to compare the patient reported outcomes between PRP and corticosteroid injection in patients with symptomatic partial thickness tears. This double blind randomized controlled trial enrolled patients with symptomatic, partial thickness rotator cuff tears or rotator cuff tendinopathy proven on ultrasound or MRI. Patients were randomized to either corticosteroid or PRP ultrasound-guided injection of the affected shoulder. Patients completed patient reported outcomes at 6 weeks and 12 weeks. The primary outcome was Visual Analog Scale (VAS) pain scores. Secondary outcomes included the Western Ontario Rotator Cuff (WORC) index, American Shoulder and Elbow Surgeons (ASES) score, and failure of non-operative management as determined by consent for surgery or progression to operative intervention. Ninety-nine patients were enrolled in the study with equal demographics between the two groups. Taking into account pre-injection scores, patients with PRP injections demonstrated a statistically significant improvement in VAS scores compared to patients receiving corticosteroid injections at 12 weeks (p=0.045) but not at 6 weeks (p=0.704). There was no difference in other outcome measures or progression of the two groups to surgical intervention. The use of PRP in the management of partial thickness rotator cuff tears demonstrates significant improvement of pain scores at 12 week follow up compared to corticosteroid injections. However, this did not affect the rate of progression to surgical intervention. Continued study is required to determine the utility of PRP in this patient population

Surgical reattachment of torn rotator cuff tendons can lead to satisfactory clinical outcome but failures remain common. Ortho-R product is a freeze-dried formulation of chitosan (CS) that is solubilized in platelet-rich plasma (PRP) to form injectable implants. The purpose of the current pilot study was to determine Ortho-R implant acute residency, test safety of different implant doses, and assess efficacy over standard of care in a sheep model. The infraspinatus tendon (ISP) was detached and immediately repaired in 22 skeletally mature ewes. Repair was done with four suture anchors in a suture bridge configuration (n = 6 controls). Freeze-dried formulations containing 1% w/v chitosan (number average molar mass 35 kDa and degree of deacetylation 83%) with 1% w/v trehalose (as lyoprotectant) and 42.2 mM calcium chloride (as clot activator) were solubilized with autologous leukocyte-rich PRP and injected at the tendon-bone interface and on top of the repaired site (n = 6 with a 1 mL dose and n = 6 with a 2 mL dose). Acute implant residency was assessed histologically at 1 day (n = 2 with a 1 mL dose and n = 2 with a 2 mL dose). Outcome measures included MRI assessment at baseline, 6 weeks and 12 weeks, histopathology at 12 weeks and clinical pathology. MRI images and histological slides were scored by 2 blinded readers (veterinarian and human radiologist, and veterinarian pathologist) and averaged. The Generalized Linear Model task (SAS Enterprise Guide 7.1 and SAS 9.4) was used to compare the different groups with post-hoc analysis to test for pairwise differences. Ortho-R implants were detected near the enthesis, near the top of the anchors holes and at the surface of ISP tendon and muscle at 1 day. Numerous polymorphonuclear cells were recruited to the implant in the case of ISP tendon and muscle. On MRI, all repair sites were hyperintense compared to normal tendon at 6 weeks and only 1 out 18 repair sites was isointense at 12 weeks. The tendon repair site gap seen on MRI, which is the length of the hyperintense region between the greater tuberosity and tendon with normal signal intensity, was decreased by treatment with the 2 mL dose when compared to control at 12 weeks (p = 0.01). Histologically, none of the repair sites were structurally normal. A trend of improved structural organization of the tendon (p = 0.06) and improved structural appearance of the enthesis (p = 0.1) with 2 mL dose treatment compared to control was seen at 12 weeks. There was no treatment-specific effect on all standard safety outcome measures, which suggests high safety. Ortho-R implants (2 mL dose) modulated the rotator cuff healing processes in this large animal model. The promising MRI and histological findings may translate into improved mechanical performance, which will be assessed in a future study with a larger number of animals. This study provides preliminary evidence on the safety and efficacy of Ortho-R implants in a large animal model that could potentially be translated to a clinical setting

Introduction: New biotechnologies create opportunities for gene therapy to promote rotator cuff healing. We have previously demonstrated that genetically engineered mesenchymal stem cells (MSCs) over expressing BMP-2 and SMAD8 signaling molecule differentiate to tenocytes in vitro and in vivo. Therefore, we hypothesized that rotator cuff defect could be regenerated using genetically engineered MSCs. Method: Nonviral methods were utilized to establish genetically engineered MSCs that co-express BMP-2 and the Smad8 signaling molecule. A previously validated animal model was utilized to examine rotator cuff healing. A 2mm x2mm full thickness defect was created in the infraspinatus tendon of 8 nude rats. A collagen-I biomembrane (TissueMend) containing 3 x 10. 6. engineered cells was sewn into the defect. An identical control procedure was repeated on the contralateral side with biomembrane containing non-engineered MSCs. Results: 4 weeks post implantation the area of implantation was isolated and analyzed by light microscopy and histochemical staining. Analysis of the engineered implants revealed the formation of dense connective tissue with parallel-organized fibers and spindle shaped cells, unlike the control samples. Proton Double Quantum Filtered Magnetic Resonance Imaging technique of the rotator cuff tendons demonstrated an increased presence of organized collagen fibers within the engineered rotator cuff tissue when compared with either native rotator cuff or those treated with non-engineered MSCs. Conclusion: This is the first report showing rotator cuff tendon repair using genetically engineered MSCs. Moreover these findings may have considerable importance for tendon healing and may indicate a clinical gene therapy platform to augment surgical repair

Bone marrow concentrates are being used to augment soft tissue healing. However, only 0.01% of these cells meet the criteria of a mesenchymal stem cell (MSC), which likely accounts for the variability in reported results. Previous studies using an established rat rotator cuff repair model have demonstrated that bone marrow-derived MSCs had no effect on healing. In this study we evaluated the effect of purified human MSCs on rotator cuff healing in an athymic rat model. Hypothesis: Purified human MSCs added to the repair site will improve biomechanical strength and fibrocartilage formation of the healing tendon. Fifty-two athymic rats underwent unilateral detachment and repair of the supraspinatus tendon with either fibrin glue (control) or fibrin glue with 106 hMSCs (experimental) applied at the repair site. Flow cytometry verified the stem cell phenotype of the cells as CD73+, CD90+, CD105+, CD14-, CD34- and CD45-. Rats were sacrificed at 2 and 4 weeks, with 10 used for biomechanical testing and 3 for histologic analysis from each group. Biomechanical testing revealed a significant increase in failure load (11.5±2.4N vs. 8.5±2.4N, p=0.002) and stiffness (7.1±1.2 N/mm vs. 5.7±2.1 N/mm, p0.17). These data demonstrate the potential for stem cells to augment tendon healing. This is the first study to use purified stem cells, rather than simple bone marrow concentrate. In the future, cell sorting techniques and culture expansion could be used to select and expand the small population of true stem cells in bone marrow. Furthermore, healing could potentially be improved with repeat cell injection at an additional post-operative time point

We assessed the clinical results, radiographic outcomes and complications of patients undergoing total shoulder replacement (TSR) for osteoarthritis with concurrent repair of a full-thickness rotator cuff tear. Between 1996 and 2010, 45 of 932 patients (4.8%) undergoing TSR for osteoarthritis underwent rotator cuff repair. The final study group comprised 33 patients with a mean follow-up of 4.7 years (3 months to 13 years). Tears were classified into small (10), medium (14), large (9) or massive (0). On a scale of 1 to 5, pain decreased from a mean of 4.7 to 1.7 (p = < 0.0001), the mean forward elevation improved from 99° to 139° (p = < 0.0001), and the mean external rotation improved from 20° (0° to 75°) to 49° (20° to 80°) (p = < 0.0001). The improvement in elevation was greater in those with a small tear (p = 0.03). Radiographic evidence of instability developed in six patients with medium or large tears, indicating lack of rotator cuff healing. In all, six glenoid components, including one with instability, were radiologically at risk of loosening. Complications were noted in five patients, all with medium or large tears; four of these had symptomatic instability and one sustained a late peri-prosthetic fracture. Four patients (12%) required further surgery, three with instability and one with a peri-prosthetic humeral fracture. . Consideration should be given to performing rotator cuff repair for stable shoulders during anatomical TSR, but reverse replacement should be considered for older, less active patients with larger tears. Cite this article: Bone Joint J 2014;96-B:224–8

Purpose of the study: Irrespective of the technique used, the average rate of bone-tendon healing after rotator cuff repair is about 50% One of the reasons is the poor vitality of the tissues implicated in repair, particularly progressive destruction of the enthesis. Using the rat Achilles tendon, we destroyed the enthesis mechanically then repaired it with and without local injection of chondrocytes in order to study the effect of cell therapy on healing phenomena. Material and method: Sixty 3-month-old Wistar rats were operated on under general anaesthesia to detach the Achilles tendon and destroy the enthesis. In the first group (RI), the tendon was reinserted via a transosseous tunnel using a 4/0 non absorbable knitted thread. In the second group (RIC), joint chondrocytes, harvested from 4-day-old rats were injected locally during the same repair procedure. Animals were sacrificed every 15 days (n=15 per group) for a biomechanical and histology study. Results: In group RI, the non-healing rate was 50% versus 33% in group RIC; the difference was not significant (n=0.3). Tear resistance was increased significantly at 45 days in the RC group (p=0.04). The histology study showed a statistically significant development of a neoenthesis in the RIC group (p< 0.05), which was not observed in the RI group. Discussion: This animal model is valid for exploring rotator cuff healing with a spontaneous rate of healing to the order of 50%. Addition of chondrocytes during the surgical repair induces the production of an enthesis and increases the healing rate 50% and the value of the different biomechanical parameters at 30 days, with a statistically significant difference at 45 days

Purpose of the study: The objective of this study was to identify clinical and anatomic factors which could affect the outcome of tendon healing after arthroscopic repair of rotator cuff tears. Material and methods: This prospective cohort study included 122 patients who underwent arthroscopic treatment between May 1999 and September 2002. One hundred twelve patients (114 shoulders) were reviewed (93.4%). Mean age at surgery was 61 years. An arthroscan (78% of patients) or magnetic resonance imaging (MRI) were performed six months postoperatively. Mean follow-up was 24 months (range 13–46 months). Results: Rotator cuff tears healed completely in 64% of the shoulders (n=73) and partially in 7% (n=8). No healing was observed in 29% (n=33). The Constant score was 49.8 preoperatively and 82.4 at last follow-up (p< 0.0001). Cuff healing improved clinical outcome with a Constant score of 85 points versus 77, particularly for force, 14.5 points versus 10 without healing. Four factors were statistically predictive of tendon healing: duration from symptom onset to operation (24 months for healed tears versus 37 months, p< 0.05); age at cuff repair (81% healed tears in patients aged less than 50 years versus 50% for patients aged over 65 years, p< 0.002); sagittal extension of the rotator interval or extension to the upper third of the infrascapularis (45% healed tears versus 79% without anterior extension, p< 0.0001); fatty degeneration (69% of healed tears for Goutallier grade 0 versus 38% for grade 1 and 2, p< 0.01). Conclusion: This study demonstrated that four factors can predict tendon healing: time to treatment, age at surgery, anterior extension of the tear, fatty degeneration

Purpose of the study: A statistical analysis of correlations between clinical outcome and anatomic results after arthroscopic repair of rotator cuff tears. Material and methods: This multicentric series of rotator cuff tears was limited to the supraspinatus and infraspinatus. The statistical analysis searched for correlations between the clinical outcome (Constant score) and anatomic results (arthroscan and arthroMRI). The series included 576 patients, mean age 57.7 years, 52%μ males and 60% manual laborers. The tear was limited to the suprapsinatus in 69% of patients, with extension to the upper third of the infraspinatus in 23.5% and all tendons in 7.5%. The supraspinatus tear was distal in 41.7% of patients, intermediary in 44% and retracted in 14.3%. Fatty degeneration of the supraspinatus was noted grade 0 in 59.7%, 1 in 27.1%, 2 in 10.8% and 3 in 2.4%. Results: The Constant score (46.3 preoperatively and 82.7 postoperatively) was strongly correlated with successful repair. The correlation was found for force, motion, and activity, but not for pain. The clinical outcome was correlated with extension, retraction, cleavage, and degeneration of the preoperative injury. The anatomic result was statistically less favorable for older, more extended, retracted, and cleaved tears or tears associated with fatty degeneration. Age was correlated with the extent of the initial tear and also with less favorable clinical and anatomic results. Work accidents were correlated with less favorable clinical outcome. Discussion: The large number of anatomic controls with contrast injection facilitated demonstration of several statistically significant correlations. This enabled disclosure in a single series of evidence confirming earlier reports in the literature: repair of cuff tears improves the overall functional outcome for massive tears; the anatomic result depends on the size of the initial tear; pre-operative fatty degeneration is an important prognostic criteria; cuff healing is age-dependent. Conclusion: Study of anatamoclinical correlations helps guide therapeutic decision making and enables the establishment of reliable prognostic criteria after arthroscopic repair of rotator cuff tears

Aims: Healing of the rotator cuff after surgical repair continues to be one of the most challenging areas of shoulder surgery. Autologous Platelet Derived Grow Factors (PDGF) have been shown to positively affect the tissue healing, but their effect have not been studied in relation to tendon healing. The purpose of this study is to evaluate if the use of PDGF in rotator cuff surgery could lead to a better and faster healing of the repair. Materials e Methods: We treated two groups (A,B) of 14 shoulders in 14 patients (mean age 66 and 63.4) with a full thickness rotator cuff tear. The group A and B were treated with a full arthroscopic repair of the cuff. In the group A, at the end of the procedure, the PDGF have been injected at the level of the lesion, between the tendon and the bone and over the tendon repair without irrigation and after the removal of all the cannulas. The group B, repaired in the same fashion, without PDGF, has been used as control. In the group A the patients had an accelerated postop. rehabilitation. The group B received a standard rehabilitation protocol. Each group has been evaluated prospectively with VAS, UCLA and Constant scores pre-op and during follow-up. Results: Both group showed an increase of the scores, compared to the pre-op. value (tab.1). The VAS score of group A (PDGF) was pre-op. 5.6 and at 1 year 1.4. The VAS score of group B (no PDGF) was pre-op. 5.2 and at 1 year 1.4. The UCLA score of group A was pre-op. 16 and at 1 year 33.8. The UCLA score of group B was pre-op. 16.7 and at 1 year 32.9. The Constant score of group A was pre-op. 53 and at 1 year 90.7. The Constant score of group B was pre-op. 54.2 and at 1 year 90.1. The complete statistical analysis of the data showed no significant differences in the results of the two groups (p< 0,01), with every kind of scores, VAS, UCLA and Constant, at the final follow-up of 1 year. Conclusions: Our data suggest that the use of PDGF, compared to a standard repair, does not affect the quality of the rotator cuff repair at 1 year. Moreover the study suggest that the use of PDGF allows an accelerated rehabilitation program with ten days of immobilization compared to four weeks as usually prescribed. Further studies should clarify the real effect of PDGF about the acceleration of the first phase of the cuff healing

Introduction and Aims: Large or recurrent rotator cuff tendon tears are difficult to treat effectively. Collagen bio-scaffolds have become available to reinforce a tendon repair or as an interpositional graft. This study compares the suitability of two collagen bio-scaffolds for autologous tenocyte implantation, and assesses the in vivo rotator cuff healing response with these grafts in a rabbit model. Method: Tenocytes were isolated from rabbit tendon, cultured and seeded onto the Restore patch (DePuy), or the Matricel (Verigen) collagen membrane. Serial scanning electron microscopy examined tenocyte integration with the bio-scaffold, and extra-cellular matrix synthesis over time. A rotator cuff tendon defect was created in 50 rabbits and repaired by either: a) direct suture to tuberosity; b) Matricel interposition graft; c) Matricel interposition with autologous tenocytes; d) Restore patch interposition graft; e) Restore patch interposition with autologous tenocytes. Gross and histological evaluation were performed at four weeks and eight weeks post-surgery. Results: Scanning electron microscopy of the Matricel membrane showed a rough surface characterised by a loose arrangement of collagen fibres capable of cell adhesion. SEM at one, three and five days after cell seeding, showed progressive integration of tenocytes into the three-dimensional membrane structure with extra-cellular matrix neosynthesis in the spaces between the native collagen fibres. SEM of the Restore patch showed a relatively smooth surface of highly compacted collagen fibres. Serial SEM after cell seeding showed relatively less tenocyte integration onto the membrane surface though tenocyte replication and matrix neo-synthesis was observed. All 50 rabbits regained normal gait at two weeks post-surgery. At sacrifice, no tendon ruptures had occurred at either time point in any of the five groups. At four weeks, the Matricel and Restore bio-scaffold membranes were partially absorbed, and a florid lymphocytic inflammatory response was evident surrounding the remaining membrane. By eight weeks, graft tissue had been resorbed further, the inflammatory response had decreased, and the regenerating tendon showed progressive remodelling. Autologous tenocyte implantation on both membranes improved the reparative tendon histological grade at eight weeks compared to membranes without cell implantation, and was equivalent to the direct repair group. Conclusion: Autologous tenocytes can be implanted onto both Matricel and Restore collagen bio-scaffolds. Though both Xeno grafts induce an anti-inflammatory response in vivo, membrane resorption subsequently occurs. The healing response of large rotator cuff defects treated with interpositional collagen grafts is improved with autologous tenocyte implantation in a rabbit model

Aims

Despite recent advances in arthroscopic rotator cuff repair, re-tear rates remain high. New methods to improve healing rates following rotator cuff repair must be sought. Our primary objective was to determine if adjunctive bone marrow stimulation with channelling five to seven days prior to arthroscopic cuff repair would lead to higher Western Ontario Rotator Cuff (WORC) scores at 24 months postoperatively compared with no channelling.

Aims

Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots.

Aims

Rotator cuff (RC) tears are common musculoskeletal injuries which often require surgical intervention. Noninvasive pulsed electromagnetic field (PEMF) devices have been approved for treatment of long-bone fracture nonunions and as an adjunct to lumbar and cervical spine fusion surgery. This study aimed to assess the effect of continuous PEMF on postoperative RC healing in a rat RC repair model.

Aims

The purpose of this study was to compare the effectiveness of surgical repair to conservative treatment and subacromial decompression for the treatment of chronic/degenerative tears of the rotator cuff.

Aims

In the context of tendon degenerative disorders, the need for innovative conservative treatments that can improve the intrinsic healing potential of tendon tissue is progressively increasing. In this study, the role of pulsed electromagnetic fields (PEMFs) in improving the tendon healing process was evaluated in a rat model of collagenase-induced Achilles tendinopathy.

Large and retracted rotator cuff tendon tears fail to repair, or re-tear following surgical intervention. This study attempted to develop novel tissue engineering approaches using tenocytes-seeded bioscaffolds for tendon reconstruction of massive rotator cuff tendon defect in rabbits. Porcine small intestine submucosa (Restore™) and type I/III collagen bioscaffold (ACI-MaixTM) were chosen as bioscaffold carriers for autologous tenocytes. Biological characterization of autologous tenocytes was conducted prior to the implantation. The tenocyte-seeded bioscaffolds were implanted as interposition grafts to reconstruct massive rotator cuff tendon defects in rabbits. In situ re-implantation of the autologous rotator cuff tendon, excised during defect creation served as a positive control. Histological outcomes were analysed and semi-quantitatively graded at four and eight weeks after surgery. The results demonstrate that at four weeks both tenocyte-seeded bioscaffolds display inflammatory reaction similar to bioscaffold-only cuff reconstruction and the histological grading were inferior to control repair. However, at eight weeks inflammatory reaction of both tenocyte-seeded bioscaffolds were dramatically reduced as compared to bioscaffold alone. In addition, bioscaf-folds seeded with tenocytes generated similar histological appearance to that of the positive control. The implantation of autologous tenocytes on collagen-based bioscaffold offers improved rotator cuff tendon healing and remodelling compared to the implantation of bioscaffold alone

Aims

The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair.