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André Mermoud - One of the best experts on this subject based on the ideXlab platform.

  • comparing deep sclerectomy with Collagen Implant to the new method of very deep sclerectomy with Collagen Implant a single masked randomized controlled trial
    Journal of Glaucoma, 2010
    Co-Authors: Kaweh Mansouri, Hoai Viet Tran, Emilie Ravinet, André Mermoud
    Abstract:

    AimTo prospectively study the intraocular pressure (IOP) lowering effect and safety of the new method of very deep sclerectomy with Collagen Implant (VDSCI) compared with standard deep sclerectomy with Collagen Implant (DSCI).MethodsThe trial involved 50 eyes of 48 patients with medically uncontroll

  • ten years follow up after deep sclerectomy with Collagen Implant
    Journal of Glaucoma, 2008
    Co-Authors: Alexandre Bissig, André Mermoud, Delphine Rivier, Marc Zaninetti, Tarek Shaarawy, Sylvain Roy
    Abstract:

    PurposeTo evaluate the long-term success rate and complications of nonpenetrating deep sclerectomy with Collagen Implant in open-angle glaucoma.Patients and MethodsClinical, prospective, monocentric, nonrandomized, unmasked study on 105 patients with medically uncontrolled glaucoma. A standard proce

  • quality of diurnal intraocular pressure control in primary open angle patients treated with latanoprost compared with surgically treated glaucoma patients a prospective trial
    British Journal of Ophthalmology, 2008
    Co-Authors: Kaweh Mansouri, André Mermoud, Emilie Ravinet, Selim Orguel, Ivan O Haefliger, Josef Flammer, Tarek Shaarawy
    Abstract:

    Purpose: To compare the IOP diurnal fluctuations of glaucoma patients treated with latanoprost 0.005% once a day to patients with controlled IOP after deep sclerectomy or trabeculectomy. Methods: The trial included 60 prospectively recruited subjects with POAG. The medical group consisted of 20 patients with controlled IOP (<18 mmHg) under latanoprost 0.005% monotherapy and with no history of previous intraocular surgery or argon laser trabeculoplasty; the surgical groups included 20 patients after trabeculectomy (TE), and 20 patients after deep sclerectomy with Collagen Implant (DSCI). The patients in the surgical groups had a controlled IOP without any ocular hypotensive medications. All patients underwent a diurnal tension curve (8.00 – 17.00/3-hour intervals), followed by a water-drinking test (WDT) with the last IOP measurement taken at 21.00. The between-group differences were tested for significance by means of analysis of variance (ANOVA). Results: Baseline IOP was significantly different between the TE group (10.1 ± 3.4 mmHg), the DSCI group (13.9 ± 2.8 mmHg) and the latanoprost group (15.5 ± 2.0 mmHg) (p = 0.005). The average IOP during the diurnal tension curve (10.1 mmHg, 13.7 mmHg , and 15.7 mmHg respectively for the groups TE, DSCI, and latanoprost) differed significantly between the groups (ANOVA: p <0.0001), but the variation was comparable in the three groups (ANOVA: p = 0.13). Following the WDT, elevation of IOP was significantly larger among patients treated with latanoprost (p = 0.003). Conclusion: Trabeculectomy patients had a statistically significant lower average IOP in the diurnal tension curve compared to the other two groups. No wider variation in diurnal IOP with latanoprost compared to the surgical procedures was found. However, IOP increase during WDT was most marked in patients under latanoprost therapy.

  • comparing polymethylmethacrylate Implant with Collagen Implant in deep sclerectomy a randomized controlled trial
    Journal of Glaucoma, 2006
    Co-Authors: Kaweh Mansouri, Tarek Shaarawy, Andreas Wedrich, André Mermoud
    Abstract:

    PURPOSE To compare the intraocular pressure (IOP) lowering effect and safety of a new rigid, nonabsorbable polymethylmethacrylate Implant (PMMA) with the commercially available cylindrical Collagen Implant used in deep sclerectomy procedure. INTERVENTION Nonpenetrating deep sclerectomy was performed on all patients. Patients were randomly assigned to receive either a PMMA Implant or a Collagen Implant. METHODS The trial involved 60 patients (60 eyes) with medically uncontrolled primary and secondary open-angle glaucoma who were randomized to receive either a PMMA Implant (30 eyes) or the Collagen Implant (30 eyes). The patients were examined before and after the operation 1 day before surgery and at day 1; weeks 1, 2 and 3; and months 1, 2, 3, 6, 9, 12, 18, 24, and 30. At each visit, the following examinations were performed: slit lamp examination, tonometry, visual acuity, and fundoscopy. RESULTS The mean follow-up period was 20.4 (SD 12.4) months (PMMA) and 15.1 (SD 7.7) months (Collagen) (P=NS). The mean preoperative IOP was 21.4 (SD 7.1) mm Hg (PMMA) and 21.0 mm Hg (SD 5.4) (Collagen). The mean postoperative IOP was 7.4 (SD 4.5) mm Hg (PMMA) and 5.4 (SD 4.4) mm Hg (Collagen) at day 1 (P=NS), 15.7 (SD 5.0) mm Hg (PMMA) and 14.7 (SD 5.0) mm Hg (Collagen) at month 1 (P=NS), and 13.8 (SD 4.8) mm Hg (PMMA) and 13.3 (SD 2.4) mm Hg (Collagen) at month 12 (P=NS). Seven patients had perforations of the trabeculo-Descemet membrane and were excluded from the analysis. At the last follow-up visit, 42% of PMMA patients and 44% of Collagen patients achieved an IOP of 21 mm Hg or less without medication (P=NS). The number of medications was reduced from 2.4 (SD 1.0) to 0.6 (SD 0.6) (P<0.001) in the PMMA group, and from 2.4 (SD 1.1) to 0.7 (SD 0.8) (P<0.001) in the Collagen group. There were no significant differences between the 2 groups in postoperative and transient complications. CONCLUSIONS The new PMMA Implant offered success and complication rates equal to those of the Collagen Implant. The new PMMA Implant could serve as a low-cost alternative to the Collagen Implant and render the use of deep sclerectomy with an Implant affordable for settings with limited financial resources.

  • deep sclerectomy in one eye vs deep sclerectomy with Collagen Implant in the contralateral eye of the same patient long term follow up
    Eye, 2005
    Co-Authors: Tarek Shaarawy, André Mermoud
    Abstract:

    To compare prospectively the results of deep sclerectomy (DS) vs deep sclerectomy with Collagen Implant (DSCI) Randomized prospective trial involving 26 eyes (13 patients) with medically uncontrolled primary and secondary open angle glaucoma. Collagen Implant was randomly assigned to one eye of each patient. The mean follow-up period was 49.5 (SD 20) months for the DS-treated eyes, and 56.5 (SD 14) months for the DSCI-treated eyes (P=0.4). The mean preoperative intraocular pressure (IOP) was 24.1 (SD 7) mmHg for the DS-treated eyes, and 25.3 (SD 6) mmHg for the DSCI-treated eyes (P=0.5). The mean IOP at the first postoperative day was 6.4 (SD 3) mmHg for the DS-treated eyes, and 3.7 (SD 2) mmHg for the DSCI-treated eyes (P=0.05). The mean IOP at 12 months postoperative day was 15.4 (SD 3) mmHg for the DS group, and 10.4 (SD 4) mmHg for the DSCI-treated eyes (P=0.04), while at 48 months it was 16 (SD 3) mmHg for the DS group, and 10 (SD 4) mmHg for the DSCI-treated eyes (P=0.005). Complete success rate, defined as an IOP lower than 21 mmHg without medication, was 38% (5/13 patients) at 48 months for the DS-treated eyes, and 69% (9/13 patients) for the DSCI-treated eyes. Qualified success rate: patients who achieved IOP below 21 mmHg with or without medication, was 69% (9/13 patients) at 48 months and 100% (13/13 patients) for the DSCI group. The mean number of medications was reduced from 2.4 (SD 0.8) to 1.1 (SD 1) after DS, and was reduced from 2.2 (SD 0.7) to 0.4 (SD 0.6) in the DSCI group (P=0.001). For those eyes treated with DSCI, IOP was 3.21 mmHg lower than for those treated with DS (P<0.0001). The use of a Collagen Implant in DS seems to enhance the success rates, provides significantly lower IOP levels, and lowers the need for postoperative medications.

Steven P Arnoczky - One of the best experts on this subject based on the ideXlab platform.

  • histologic evaluation of biopsy specimens obtained after rotator cuff repair augmented with a highly porous Collagen Implant
    Arthroscopy, 2017
    Co-Authors: Steven P Arnoczky, Shariff K Bishai, Brian Schofield, Scott A Sigman, Brad D Bushnell, Jan Pieter Hommen, Craig Van Kampen
    Abstract:

    Purpose To histologically evaluate biopsy specimens from patients who previously underwent rotator cuff repair augmented with a highly porous Collagen Implant. Methods Biopsies of Collagen Implant/host-tissue constructs were obtained from 7 patients undergoing a second arthroscopic procedure at various time periods (5 weeks to 6 months) after arthroscopic rotator cuff repair augmented with a Collagen Implant overlay. The biopsy specimens were examined histologically for host-tissue ingrowth, host-tissue maturation, and host-Implant biocompatibility. Results At the earliest time period (5 weeks), the biopsy revealed the presence of host cells (fibroblasts) within the interstices of the porous Collagen Implant. Cells were aligned along the linear orientation of the Collagen Implant structure, and there was evidence of early Collagen formation. The 3-month biopsies showed increased Collagen formation, maturation, and organization over the surface of the Implant and evidence of the Collagen Implant. At 6 months, the newly generated tissue had the histologic appearance of a tendon, suggesting functional loading of the new generated host tissue. There was no evidence of any remnants of the Collagen Implant in the 6-month biopsy. There was no evidence of any inflammatory or foreign body reaction within any of the tissue samples. Conclusions Biopsies of Collagen Implants retrieved from human rotator cuff repair subjects revealed cellular incorporation, tissue formation and maturation, Implant resorption, and biocompatibility. Clinical Relevance The histologic observations from these clinical biopsies support the biocompatibility of this Implant and its ability to promote new connective tissue with the histological appearance of tendon over the surface of the native cuff tendon.

  • evidence of healing of partial thickness rotator cuff tears following arthroscopic augmentation with a Collagen Implant a 2 year mri follow up
    Muscles ligaments and tendons journal, 2016
    Co-Authors: Desmond J Bokor, Craig Van Kampen, David H Sonnabend, Luke Deady, Allan A Young, Ben Cass, Steven P Arnoczky
    Abstract:

    partial-thickness rotator cuff tears frequently enlarge due to increased local strain and often progress to full-thickness tears. Studies suggest the addition of new tendinous tissue to injured cuff tendons would significantly decrease peak strain, possibly protecting against tear progression. The aim of this study was to assess the ability of a highly-porous Collagen Implant to induce new tissue formation and limit tear progression when placed on the bursal surface of partial-thickness cuff tears.

  • preliminary investigation of a biological augmentation of rotator cuff repairs using a Collagen Implant a 2 year mri follow up
    Muscles ligaments and tendons journal, 2015
    Co-Authors: Desmond J Bokor, David H Sonnabend, Luke Deady, Benjamin Cass, Allan A Young, Van Kampen C, Steven P Arnoczky
    Abstract:

    the inability to restore the normal tendon footprint and limit strains on the repair site are thought to contribute to re-tearing following rotator cuff repair. The purpose of this study was to use a Collagen Implant to augment rotator cuff repairs through the restoration of the native tendon footprint and the induction of new tissue to decrease overall tendon strain.repairs of full-thickness rotator cuff lesions in 9 adult patients were augmented with a novel Collagen Implant placed over the bursal surface of the repair. Tendon thickness and footprint anatomy were evaluated using MRI at 3, 6, 12, and 24 months. Clinical results were assessed using standard outcome metrics. Mean follow-up for all patients was 25.8 months.the Implant induced significant new tissue formation in all patients by 3 months. This tissue matured over time and became indistinguishable from the underlying tendon. At 24 months all repairs remained intact and normal footprint anatomy of the tendon was restored in all patients. All clinical scores improved significantly over time.the ability of a Collagen Implant to induce new host tissue formation and restore the normal footprint anatomy may represent a significant advancement in the biological augmentation and ultimate durability of rotator cuff repairs.

  • preliminary investigation of a biological augmentation of rotator cuff repairs using a Collagen Implant a 2 year mri follow up
    Muscles ligaments and tendons journal, 2015
    Co-Authors: Desmond J Bokor, Craig Van Kampen, David H Sonnabend, Luke Deady, Allan A Young, Ben Cass, Steven P Arnoczky
    Abstract:

    BACKGROUND the inability to restore the normal tendon footprint and limit strains on the repair site are thought to contribute to re-tearing following rotator cuff repair. The purpose of this study was to use a Collagen Implant to augment rotator cuff repairs through the restoration of the native tendon footprint and the induction of new tissue to decrease overall tendon strain. METHODS repairs of full-thickness rotator cuff lesions in 9 adult patients were augmented with a novel Collagen Implant placed over the bursal surface of the repair. Tendon thickness and footprint anatomy were evaluated using MRI at 3, 6, 12, and 24 months. Clinical results were assessed using standard outcome metrics. Mean follow-up for all patients was 25.8 months. RESULTS the Implant induced significant new tissue formation in all patients by 3 months. This tissue matured over time and became indistinguishable from the underlying tendon. At 24 months all repairs remained intact and normal footprint anatomy of the tendon was restored in all patients. All clinical scores improved significantly over time. CONCLUSION the ability of a Collagen Implant to induce new host tissue formation and restore the normal footprint anatomy may represent a significant advancement in the biological augmentation and ultimate durability of rotator cuff repairs.

Ali Moshiri - One of the best experts on this subject based on the ideXlab platform.

  • synthesis development characterization and effectiveness of bovine pure platelet gel Collagen polydioxanone bioactive graft on tendon healing
    Journal of Cellular and Molecular Medicine, 2015
    Co-Authors: Ali Moshiri, Ahmad Oryan, Abdolhamid Meimandiparizi
    Abstract:

    Bovine platelet gel (BPG) is an accessible and cost-effective source of growth factors which may have a value in tendon regenerative medicine. We produced a Collagen Implant (CI) as a tendon proper, covered it with polydioxanone (PDS) sheath to simulate paratenon and finally embedded the BPG as an active source of growth factor within the bioImplant to test whether BPG would be able to accelerate and enhance tendon regeneration and repair. After in vitro characterization of the bioactive grafts, the grafts were Implanted in rabbit large tendon defect model. Untreated tendons and tendons treated with either CI or CI-PDS were served as controls for the CI-PDS-BPG. The animals were investigated clinically, ultrasonographically and haematologically for 120 days. After euthanasia, dry matter content, water uptake and delivery characteristics and also gross morphological, histopathological and scanning electron microscopic features of the healing tendons were assessed. In vitro, the activated platelets in the scaffold, released their growth factors significantly more than the controls. BPG also increased cell viability, and enhanced cellular differentiation, maturation and proliferation inside the CI-PDS compared with the controls. In vivo, the BPG modulated inflammation, increased quality and rate of fibroplasia and produced a remodelled tendon that had significantly higher Collagen content and superior Collagen fibril and fibre differentiation than controls. Treatment also significantly improved tendon water uptake and delivery characteristics, animals’ serum PDGF level, CI-PDS biocompatibility and biodegradability and reduced peritendinous adhesions, muscle fibrosis and atrophy. BPG was effective on tendon healing and CI-PDS-BPG may be a valuable bioscaffold in tendon reconstructive surgery.

  • role of xenogenous bovine platelet gel embedded within Collagen Implant on tendon healing an in vitro and in vivo study
    Experimental Biology and Medicine, 2015
    Co-Authors: Ahmad Oryan, Ali Moshiri, Abdolhamid Meimandiparizi, Nicola Maffulli
    Abstract:

    Surgical reconstruction of large Achilles tendon defects is demanding. Platelet concentrates may be useful to favor healing in such conditions. The characteristics of bovine platelet-gel embedded within a Collagen-Implant were determined in vitro, and its healing efficacy was examined in a large Achilles tendon defect in rabbits. Two cm of the left Achilles tendon of 60 rabbits were excised, and the animals were randomly assigned to control (no Implant), Collagen-Implant, or bovine-platelet-gel-Collagen-Implant groups. The tendon edges were maintained aligned using a Kessler suture. No Implant was inserted in the control group. In the two other groups, a Collagen-Implant or bovine-platelet-gel-Collagen-Implant was inserted in the defect. The bioelectricity and serum platelet-derived growth factor levels were measured weekly and at 60 days post injury, respectively. After euthanasia at 60 days post injury, the tendons were tested at macroscopic, microscopic, and ultrastructural levels, and their dry matter and biomechanical performances were also assessed. Another 60 rabbits were assigned to receive no Implant, a Collagen-Implant, or a bovine-platelet-gel-Collagen-Implant, euthanized at 10, 20, 30, and 40 days post injury, and their tendons were evaluated grossly and histologically to determine host-graft interactions. Compared to the control and Collagen-Implant, treatment with bovine-platelet-gel-Collagen-Implant improved tissue bioelectricity and serum platelet-derived growth factor levels, and increased cell proliferation, differentiation, and maturation. It also increased number, diameter, and density of the Collagen fibrils, alignment and maturation of the Collagen fibrils and fibers, biomechanical properties and dry matter content of the injured tendons at 60 days post injury. The bovine-platelet-gel-Collagen-Implant also increased biodegradability, biocompatibility, and tissue incorporation behavior of the Implant compared to the Collagen-Implant alone. This treatment also decreased tendon adhesion, muscle fibrosis, and atrophy, and improved the physical activity of the animals. The bovine-platelet-gel-Collagen-Implant was effective in neotenon formation in vivo, which may be valuable in the clinical setting.

  • effectiveness of xenogenous based bovine derived platelet gel embedded within a three dimensional Collagen Implant on the healing and regeneration of the achilles tendon defect in rabbits
    Expert Opinion on Biological Therapy, 2014
    Co-Authors: Ali Moshiri, Abdolhamid Meimandiparizi, Ahmad Oryan, Omid Koohihosseinabadi
    Abstract:

    Background and objective: Tissue engineering is an option in reconstructing large tendon defects and managing their healing and regeneration. We designed and produced a novel xenogeneic-based bovine platelet, embedded it within a tissue-engineered Collagen Implant (CI) and applied it in an experimentally induced large tendon defect model in rabbits to test whether bovine platelets could stimulate tendon healing and regeneration in vivo. Methods: One hundred twenty rabbits were randomly divided into two experimental and pilot groups. In all the animals, the left Achilles tendon was surgically excised and the tendon edges were aligned by Kessler suture. Each group was then divided into three groups of control (no Implant), treated with CI and treated with Collagen-platelet Implant. The pilot groups were euthanized at 10, 15, 30 and 40 days post-injury (DPI), and their gross and histologic characteristics were evaluated to study host–graft interaction mechanism. To study the tendon healing and its outcome, the experimental animals were tested during the experiment using hematologic, ultrasonographic and various methods of clinical examinations and then euthanized at 60 DPI and their tendons were evaluated by gross pathologic, histopathologic, scanning electron microscopic, biophysical and biochemical methods. Results: Bovine platelets embedded within a CI increased inflammation at short term while it increased the rate of Implant absorption and matrix replacement compared with the controls and CI alone. Treatment also significantly increased diameter, density, amount, alignment and differentiation of the Collagen fibrils and fibers and approximated the water uptake and delivery behavior of the healing tendons to normal contralaterals (p < 0.05). Treatment also improved echogenicity and homogenicity of the tendons and reduced peritendinous adhesion, muscle fibrosis and atrophy, and therefore, it improved the clinical scores and physical activity related to the injured limb when compared with the controls (p < 0.05). Conclusion: The bovine platelet gel embedded within the tissue-engineered CI was effective in healing, modeling and remodeling of the Achilles tendon in rabbit. This strategy may be a valuable option in the clinical setting.

  • tendon tissue engineering and its role on healing of the experimentally induced large tendon defect model in rabbits a comprehensive in vivo study
    PLOS ONE, 2013
    Co-Authors: Abdolhamid Meimandiparizi, Ahmad Oryan, Ali Moshiri
    Abstract:

    Healing of large tendon defects is challenging. We studied the role of Collagen Implant with or without polydioxanone (PDS) sheath on the healing of a large Achilles tendon defect model, in rabbits. Sixty rabbits were divided into three groups. A 2 cm gap was created in the left Achilles tendon of all rabbits. In the control lesions, no Implant was used. The other two groups were reconstructed by Collagen and Collagen-PDS Implants respectively. The animals were clinically examined at weekly intervals and their lesions were observed by ultrasonography. Blood samples were obtained from the animals and were assessed for hematological analysis and determination of serum PDGF level, at 60 days post injury (DPI). The animals were then euthanized and their lesions were assessed for gross and histopathology, scanning electron microscopy, biomechanical testing, dry matter and hydroxyproline content. Another 65 pilot animals were also studied grossly and histopathologically to define the host Implant interaction and graft incorporation at serial time points. The treated animals gained significantly better clinical scoring compared to the controls. Treatment with Collagen and Collagen-PDS Implants significantly increased the biomechanical properties of the lesions compared to the control tendons at 60 DPI (P<0.05). The tissue engineered Implants also reduced peritendinous adhesion, muscle fibrosis and atrophy, and increased ultrasonographical echogenicity and homogenicity, maturation and differentiation of the Collagen fibrils and fibers, tissue alignment and volume of the regenerated tissue compared to those of the control lesions (P<0.05). The Implants were gradually absorbed and substituted by the new tendon. Implantation of the bioImplants had a significant role in initiating tendon healing and the Implants were biocompatible, biodegradable and safe for application in tendon reconstructive surgery. The results of the present study may be valuable in clinical practice.

  • role of tissue engineered Collagen based tridimensional Implant on the healing response of the experimentally induced large achilles tendon defect model in rabbits a long term study with high clinical relevance
    Journal of Biomedical Science, 2013
    Co-Authors: Abdolhamid Meimandiparizi, Ahmad Oryan, Ali Moshiri
    Abstract:

    Tendon injury is one of the orthopedic conditions poses with a significant clinical challenge to both the surgeons and patients. The major limitations to manage these injuries are poor healing response and development of peritendinous adhesions in the injured area. This study investigated the effectiveness of a novel Collagen Implant on tendon healing in rabbits. Seventy five mature White New-Zealand rabbits were divided into treated (n = 55) and control (n = 20) groups. The left Achilles tendon was completely transected and 2 cm excised. The defects of the treated animals were filled with Collagen Implants and repaired with sutures, but in control rabbits the defects were sutured similarly but the gap was left untreated. Changes in the injured and normal contralateral tendons were assessed weekly by measuring the diameter, temperature and bioelectrical characteristics of the injured area. Clinical examination was done and scored. Among the treated animals, small pilot groups were euthanized at 5, 10, 15, 20, 30, 40 and 60 (n = 5 at each time interval) and the remainder (n = 20) and the control animals at 120 days post injury (DPI). The lesions of all animals were examined at macroscopic and microscopic levels and the dry matter content, water delivery and water uptake characteristics of the lesions and normal contralateral tendons of both groups were analyzed at 120 DPI. No sign of rejection was seen in the treated lesions. The Collagen Implant was invaded by the inflammatory cells at the inflammatory phase, followed by fibroplasia phase in which remnant of the Collagen Implant were still present while no inflammatory reaction could be seen in the lesions. However, the Collagen Implant was completely absorbed in the remodeling phase and the newly regenerated tendinous tissue filled the gap. Compared to the controls, the treated lesions showed improved tissue alignment and less peritendinous adhesion, muscle atrophy and fibrosis. They also showed significantly better clinical scoring, indices for water uptake and water absorption, and bioelectrical characteristics than the controls. This novel Collagen Implant was biodegradable, biocompatible and possibly could be considered as a substitute for auto and allografts in clinical practice in near future.

Brandon D Bushnell - One of the best experts on this subject based on the ideXlab platform.

  • 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
    Journal of Shoulder and Elbow Surgery, 2021
    Co-Authors: Theodore F Schlegel, Jeffrey S Abrams, Richard L Angelo, Mark H Getelman, Brandon D Bushnell
    Abstract:

    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.

  • 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
    JSES international, 2021
    Co-Authors: Brandon D Bushnell, Patrick M Connor, Howard W Harris, Scott W Trenhaile, Jeffrey S Abrams
    Abstract:

    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.

  • patient reported outcomes after use of a bioabsorbable Collagen Implant to treat partial and full thickness rotator cuff tears
    Arthroscopy, 2019
    Co-Authors: Louis F Mcintyre, Shariff K Bishai, Brandon D Bushnell, Paul B Brown, Scott W Trenhaile
    Abstract:

    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 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.

  • radiologic and clinical evaluation of a bioabsorbable Collagen Implant to treat partial thickness tears a prospective multicenter study
    Journal of Shoulder and Elbow Surgery, 2018
    Co-Authors: Theodore F Schlegel, Brandon D Bushnell, Jeffrey S Abrams, Logan J Brock
    Abstract:

    Background Treatment of partial-thickness cuff tears remains controversial. Although conservative therapy may treat symptoms, these defects do not spontaneously heal and conversion to a full-thickness lesion with subsequent repair may alter the tendon footprint. The ability to induce new tissue formation and limit tear progression in intermediate- and high-grade partial-thickness tears without surgical repair may represent a significant advancement in the treatment paradigm for these lesions. 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. Following arthroscopic subacromial decompression without repair, a bioinductive Implant was attached over the bursal surface of the tendon. Clinical outcomes were assessed using American Shoulder and Elbow Surgeons and Constant-Murley scores preoperatively and at 3 and 12 months postoperatively. Magnetic resonance imaging was performed to assess postoperative tendon healing and thickness at the original tear site. Results At 1-year follow-up, clinical scores improved significantly (P  Conclusions Arthroscopic Implantation of a bioinductive Collagen scaffold is a safe and effective treatment for intermediate- to high-grade partial-thickness rotator cuff tears of the supraspinatus tendon.

Abdolhamid Meimandiparizi - One of the best experts on this subject based on the ideXlab platform.

  • synthesis development characterization and effectiveness of bovine pure platelet gel Collagen polydioxanone bioactive graft on tendon healing
    Journal of Cellular and Molecular Medicine, 2015
    Co-Authors: Ali Moshiri, Ahmad Oryan, Abdolhamid Meimandiparizi
    Abstract:

    Bovine platelet gel (BPG) is an accessible and cost-effective source of growth factors which may have a value in tendon regenerative medicine. We produced a Collagen Implant (CI) as a tendon proper, covered it with polydioxanone (PDS) sheath to simulate paratenon and finally embedded the BPG as an active source of growth factor within the bioImplant to test whether BPG would be able to accelerate and enhance tendon regeneration and repair. After in vitro characterization of the bioactive grafts, the grafts were Implanted in rabbit large tendon defect model. Untreated tendons and tendons treated with either CI or CI-PDS were served as controls for the CI-PDS-BPG. The animals were investigated clinically, ultrasonographically and haematologically for 120 days. After euthanasia, dry matter content, water uptake and delivery characteristics and also gross morphological, histopathological and scanning electron microscopic features of the healing tendons were assessed. In vitro, the activated platelets in the scaffold, released their growth factors significantly more than the controls. BPG also increased cell viability, and enhanced cellular differentiation, maturation and proliferation inside the CI-PDS compared with the controls. In vivo, the BPG modulated inflammation, increased quality and rate of fibroplasia and produced a remodelled tendon that had significantly higher Collagen content and superior Collagen fibril and fibre differentiation than controls. Treatment also significantly improved tendon water uptake and delivery characteristics, animals’ serum PDGF level, CI-PDS biocompatibility and biodegradability and reduced peritendinous adhesions, muscle fibrosis and atrophy. BPG was effective on tendon healing and CI-PDS-BPG may be a valuable bioscaffold in tendon reconstructive surgery.

  • role of xenogenous bovine platelet gel embedded within Collagen Implant on tendon healing an in vitro and in vivo study
    Experimental Biology and Medicine, 2015
    Co-Authors: Ahmad Oryan, Ali Moshiri, Abdolhamid Meimandiparizi, Nicola Maffulli
    Abstract:

    Surgical reconstruction of large Achilles tendon defects is demanding. Platelet concentrates may be useful to favor healing in such conditions. The characteristics of bovine platelet-gel embedded within a Collagen-Implant were determined in vitro, and its healing efficacy was examined in a large Achilles tendon defect in rabbits. Two cm of the left Achilles tendon of 60 rabbits were excised, and the animals were randomly assigned to control (no Implant), Collagen-Implant, or bovine-platelet-gel-Collagen-Implant groups. The tendon edges were maintained aligned using a Kessler suture. No Implant was inserted in the control group. In the two other groups, a Collagen-Implant or bovine-platelet-gel-Collagen-Implant was inserted in the defect. The bioelectricity and serum platelet-derived growth factor levels were measured weekly and at 60 days post injury, respectively. After euthanasia at 60 days post injury, the tendons were tested at macroscopic, microscopic, and ultrastructural levels, and their dry matter and biomechanical performances were also assessed. Another 60 rabbits were assigned to receive no Implant, a Collagen-Implant, or a bovine-platelet-gel-Collagen-Implant, euthanized at 10, 20, 30, and 40 days post injury, and their tendons were evaluated grossly and histologically to determine host-graft interactions. Compared to the control and Collagen-Implant, treatment with bovine-platelet-gel-Collagen-Implant improved tissue bioelectricity and serum platelet-derived growth factor levels, and increased cell proliferation, differentiation, and maturation. It also increased number, diameter, and density of the Collagen fibrils, alignment and maturation of the Collagen fibrils and fibers, biomechanical properties and dry matter content of the injured tendons at 60 days post injury. The bovine-platelet-gel-Collagen-Implant also increased biodegradability, biocompatibility, and tissue incorporation behavior of the Implant compared to the Collagen-Implant alone. This treatment also decreased tendon adhesion, muscle fibrosis, and atrophy, and improved the physical activity of the animals. The bovine-platelet-gel-Collagen-Implant was effective in neotenon formation in vivo, which may be valuable in the clinical setting.

  • effectiveness of xenogenous based bovine derived platelet gel embedded within a three dimensional Collagen Implant on the healing and regeneration of the achilles tendon defect in rabbits
    Expert Opinion on Biological Therapy, 2014
    Co-Authors: Ali Moshiri, Abdolhamid Meimandiparizi, Ahmad Oryan, Omid Koohihosseinabadi
    Abstract:

    Background and objective: Tissue engineering is an option in reconstructing large tendon defects and managing their healing and regeneration. We designed and produced a novel xenogeneic-based bovine platelet, embedded it within a tissue-engineered Collagen Implant (CI) and applied it in an experimentally induced large tendon defect model in rabbits to test whether bovine platelets could stimulate tendon healing and regeneration in vivo. Methods: One hundred twenty rabbits were randomly divided into two experimental and pilot groups. In all the animals, the left Achilles tendon was surgically excised and the tendon edges were aligned by Kessler suture. Each group was then divided into three groups of control (no Implant), treated with CI and treated with Collagen-platelet Implant. The pilot groups were euthanized at 10, 15, 30 and 40 days post-injury (DPI), and their gross and histologic characteristics were evaluated to study host–graft interaction mechanism. To study the tendon healing and its outcome, the experimental animals were tested during the experiment using hematologic, ultrasonographic and various methods of clinical examinations and then euthanized at 60 DPI and their tendons were evaluated by gross pathologic, histopathologic, scanning electron microscopic, biophysical and biochemical methods. Results: Bovine platelets embedded within a CI increased inflammation at short term while it increased the rate of Implant absorption and matrix replacement compared with the controls and CI alone. Treatment also significantly increased diameter, density, amount, alignment and differentiation of the Collagen fibrils and fibers and approximated the water uptake and delivery behavior of the healing tendons to normal contralaterals (p < 0.05). Treatment also improved echogenicity and homogenicity of the tendons and reduced peritendinous adhesion, muscle fibrosis and atrophy, and therefore, it improved the clinical scores and physical activity related to the injured limb when compared with the controls (p < 0.05). Conclusion: The bovine platelet gel embedded within the tissue-engineered CI was effective in healing, modeling and remodeling of the Achilles tendon in rabbit. This strategy may be a valuable option in the clinical setting.

  • tendon tissue engineering and its role on healing of the experimentally induced large tendon defect model in rabbits a comprehensive in vivo study
    PLOS ONE, 2013
    Co-Authors: Abdolhamid Meimandiparizi, Ahmad Oryan, Ali Moshiri
    Abstract:

    Healing of large tendon defects is challenging. We studied the role of Collagen Implant with or without polydioxanone (PDS) sheath on the healing of a large Achilles tendon defect model, in rabbits. Sixty rabbits were divided into three groups. A 2 cm gap was created in the left Achilles tendon of all rabbits. In the control lesions, no Implant was used. The other two groups were reconstructed by Collagen and Collagen-PDS Implants respectively. The animals were clinically examined at weekly intervals and their lesions were observed by ultrasonography. Blood samples were obtained from the animals and were assessed for hematological analysis and determination of serum PDGF level, at 60 days post injury (DPI). The animals were then euthanized and their lesions were assessed for gross and histopathology, scanning electron microscopy, biomechanical testing, dry matter and hydroxyproline content. Another 65 pilot animals were also studied grossly and histopathologically to define the host Implant interaction and graft incorporation at serial time points. The treated animals gained significantly better clinical scoring compared to the controls. Treatment with Collagen and Collagen-PDS Implants significantly increased the biomechanical properties of the lesions compared to the control tendons at 60 DPI (P<0.05). The tissue engineered Implants also reduced peritendinous adhesion, muscle fibrosis and atrophy, and increased ultrasonographical echogenicity and homogenicity, maturation and differentiation of the Collagen fibrils and fibers, tissue alignment and volume of the regenerated tissue compared to those of the control lesions (P<0.05). The Implants were gradually absorbed and substituted by the new tendon. Implantation of the bioImplants had a significant role in initiating tendon healing and the Implants were biocompatible, biodegradable and safe for application in tendon reconstructive surgery. The results of the present study may be valuable in clinical practice.

  • role of tissue engineered Collagen based tridimensional Implant on the healing response of the experimentally induced large achilles tendon defect model in rabbits a long term study with high clinical relevance
    Journal of Biomedical Science, 2013
    Co-Authors: Abdolhamid Meimandiparizi, Ahmad Oryan, Ali Moshiri
    Abstract:

    Tendon injury is one of the orthopedic conditions poses with a significant clinical challenge to both the surgeons and patients. The major limitations to manage these injuries are poor healing response and development of peritendinous adhesions in the injured area. This study investigated the effectiveness of a novel Collagen Implant on tendon healing in rabbits. Seventy five mature White New-Zealand rabbits were divided into treated (n = 55) and control (n = 20) groups. The left Achilles tendon was completely transected and 2 cm excised. The defects of the treated animals were filled with Collagen Implants and repaired with sutures, but in control rabbits the defects were sutured similarly but the gap was left untreated. Changes in the injured and normal contralateral tendons were assessed weekly by measuring the diameter, temperature and bioelectrical characteristics of the injured area. Clinical examination was done and scored. Among the treated animals, small pilot groups were euthanized at 5, 10, 15, 20, 30, 40 and 60 (n = 5 at each time interval) and the remainder (n = 20) and the control animals at 120 days post injury (DPI). The lesions of all animals were examined at macroscopic and microscopic levels and the dry matter content, water delivery and water uptake characteristics of the lesions and normal contralateral tendons of both groups were analyzed at 120 DPI. No sign of rejection was seen in the treated lesions. The Collagen Implant was invaded by the inflammatory cells at the inflammatory phase, followed by fibroplasia phase in which remnant of the Collagen Implant were still present while no inflammatory reaction could be seen in the lesions. However, the Collagen Implant was completely absorbed in the remodeling phase and the newly regenerated tendinous tissue filled the gap. Compared to the controls, the treated lesions showed improved tissue alignment and less peritendinous adhesion, muscle atrophy and fibrosis. They also showed significantly better clinical scoring, indices for water uptake and water absorption, and bioelectrical characteristics than the controls. This novel Collagen Implant was biodegradable, biocompatible and possibly could be considered as a substitute for auto and allografts in clinical practice in near future.