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Grenier S, Donnelly PE, Gittens J, Torzilli PA. Resurfacing damaged articular cartilage to restore compressive properties. J Biomech 2015; 48:122-9. [PMID: 25468298 PMCID: PMC4420241 DOI: 10.1016/j.jbiomech.2014.10.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 08/28/2014] [Accepted: 10/19/2014] [Indexed: 01/02/2023]
Abstract
Surface damage to articular cartilage is recognized as the initial underlying process causing the loss of mechanical function in early-stage osteoarthritis. In this study, we developed structure-modifying treatments to potentially prevent, stabilize or reverse the loss in mechanical function. Various polymers (chondroitin sulfate, carboxymethylcellulose, sodium hyaluronate) and photoinitiators (riboflavin, irgacure 2959) were applied to the surface of collagenase-degraded cartilage and crosslinked in situ using UV light irradiation. While matrix permeability and deformation significantly increased following collagenase-induced degradation of the superficial zone, resurfacing using tyramine-substituted sodium hyaluronate and riboflavin decreased both values to a level comparable to that of intact cartilage. Repetitive loading of resurfaced cartilage showed minimal variation in the mechanical response over a 7 day period. Cartilage resurfaced using a low concentration of riboflavin had viable cells in all zones while a higher concentration resulted in a thin layer of cell death in the uppermost superficial zone. Our approach to repair surface damage initiates a new therapeutic advance in the treatment of injured articular cartilage with potential benefits that include enhanced mechanical properties, reduced susceptibility to enzymatic degradation and reduced adhesion of macrophages.
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Affiliation(s)
- Stephanie Grenier
- Laboratory for Soft Tissue Research, Tissue Engineering, Regeneration and Repair Program, The Hospital for Special Surgery, New York, NY 10021, USA.
| | - Patrick E Donnelly
- Laboratory for Soft Tissue Research, Tissue Engineering, Regeneration and Repair Program, The Hospital for Special Surgery, New York, NY 10021, USA
| | - Jamila Gittens
- Laboratory for Soft Tissue Research, Tissue Engineering, Regeneration and Repair Program, The Hospital for Special Surgery, New York, NY 10021, USA
| | - Peter A Torzilli
- Laboratory for Soft Tissue Research, Tissue Engineering, Regeneration and Repair Program, The Hospital for Special Surgery, New York, NY 10021, USA
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Oungoulian SR, Hehir KE, Zhu K, Willis CE, Marinescu AG, Merali N, Ahmad CS, Hung CT, Ateshian GA. Effect of glutaraldehyde fixation on the frictional response of immature bovine articular cartilage explants. J Biomech 2013; 47:694-701. [PMID: 24332617 DOI: 10.1016/j.jbiomech.2013.11.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 11/19/2013] [Accepted: 11/24/2013] [Indexed: 10/25/2022]
Abstract
This study examined functional properties and biocompatibility of glutaraldehyde-fixed bovine articular cartilage over several weeks of incubation at body temperature to investigate its potential use as a resurfacing material in joint arthroplasty. In the first experiment, treated cartilage disks were fixed using 0.02, 0.20 and 0.60% glutaraldehyde for 24h then incubated, along with an untreated control group, in saline for up to 28d at 37°C. Both the equilibrium compressive and tensile moduli increased nearly twofold in treated samples compared to day 0 control, and remained at that level from day 1 to 28; the equilibrium friction coefficient against glass rose nearly twofold immediately after fixation (day 1) but returned to control values after day 7. Live explants co-cultured with fixed explants showed no quantitative difference in cell viability over 28d. In general, no significant differences were observed between 0.20 and 0.60% groups, so 0.20% was deemed sufficient for complete fixation. In the second experiment, cartilage-on-cartilage frictional measurements were performed under a migrating contact configuration. In the treated group, one explant was fixed using 0.20% glutaraldehyde while the apposing explant was left untreated; in the control group both explants were left untreated. From day 1 to 28, the treated group exhibited either no significant difference or slightly lower friction coefficient than the untreated group. These results suggest that a properly titrated glutaraldehyde treatment can reproduce the desired functional properties of native articular cartilage and maintain these properties for at least 28d at body temperature.
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Affiliation(s)
- Sevan R Oungoulian
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Kristin E Hehir
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Kaicen Zhu
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Callen E Willis
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Anca G Marinescu
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Natasha Merali
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | | | - Clark T Hung
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Gerard A Ateshian
- Department of Mechanical Engineering, Columbia University, New York, NY, USA; Department of Biomedical Engineering, Columbia University, New York, NY, USA.
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Cissell DD, Hu JC, Griffiths LG, Athanasiou KA. Antigen removal for the production of biomechanically functional, xenogeneic tissue grafts. J Biomech 2013; 47:1987-96. [PMID: 24268315 DOI: 10.1016/j.jbiomech.2013.10.041] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/16/2013] [Accepted: 10/19/2013] [Indexed: 10/26/2022]
Abstract
Xenogeneic tissues are derived from other animal species and provide a source of material for engineering mechanically functional tissue grafts, such as heart valves, tendons, ligaments, and cartilage. Xenogeneic tissues, however, contain molecules, known as antigens, which invoke an immune reaction following implantation into a patient. Therefore, it is necessary to remove the antigens from a xenogeneic tissue to prevent immune rejection of the graft. Antigen removal can be accomplished by treating a tissue with solutions and/or physical processes that disrupt cells and solubilize, degrade, or mask antigens. However, processes used for cell and antigen removal from tissues often have deleterious effects on the extracellular matrix (ECM) of the tissue, rendering the tissue unsuitable for implantation due to poor mechanical properties. Thus, the goal of an antigen removal process should be to reduce the antigen content of a xenogeneic tissue while preserving its mechanical functionality. To expand the clinical use of antigen-removed xenogeneic tissues as biomechanically functional grafts, it is essential that researchers examine tissue antigen content, ECM composition and architecture, and mechanical properties as new antigen removal processes are developed.
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Affiliation(s)
- Derek D Cissell
- Department of Orthopaedic Surgery, University of California, Davis, CA, USA; Department of Surgical and Radiological Sciences, University of California, Davis, CA, USA
| | - Jerry C Hu
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Leigh G Griffiths
- Department of Veterinary Medicine: Medicine and Epidemiology, University of California, Davis, CA, USA
| | - Kyriacos A Athanasiou
- Department of Biomedical Engineering, University of California, Davis, CA, USA; Department of Orthopaedic Surgery, University of California, Davis, CA, USA.
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Zumstein MA, Frey E, von Rechenberg B, Frigg R, Gerber C, Meyer DC. Device for lengthening of a musculotendinous unit by direct continuous traction in the sheep. BMC Vet Res 2012; 8:50. [PMID: 22551079 PMCID: PMC3462135 DOI: 10.1186/1746-6148-8-50] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 04/18/2012] [Indexed: 11/10/2022] Open
Abstract
Background Retraction, atrophy and fatty infiltration are signs subsequent to chronic rotator cuff tendon tears. They are associated with an increased pennation angle and a shortening of the muscle fibers in series. These deleterious changes of the muscular architecture are not reversible with current repair techniques and are the main factors for failed rotator cuff tendon repair. Whereas fast stretching of the retracted musculotendinous unit results in proliferation of non-contractile fibrous tissue, slow stretching may lead to muscle regeneration in terms of sarcomerogenesis. To slowly stretch the retracted musculotendinous unit in a sheep model, two here described tensioning devices have been developed and mounted on the scapular spine of the sheep using an expandable threaded rod, which has been interposed between the retracted tendon end and the original insertion site at the humeral head. Traction is transmitted in line with the musculotendinous unit by sutures knotted on the expandable threaded rod. The threaded rod of the tensioner is driven within the body through a rotating axis, which enters the body on the opposite side. The tendon end, which was previously released (16 weeks prior) from its insertion site with a bone chip, was elongated with a velocity of 1 mm/day. Results After several steps of technical improvements, the tensioner proved to be capable of actively stretching the retracted and degenerated muscle back to the original length and to withstand the external forces acting on it. Conclusion This technical report describes the experimental technique for continuous elongation of the musculotendinous unit and reversion of the length of chronically shortened muscle.
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Affiliation(s)
- Matthias A Zumstein
- Dept. of Orthopedics, University of Zurich, Balgrist, Zürich, 8008, Switzerland
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Revell CM, Athanasiou KA. Success rates and immunologic responses of autogenic, allogenic, and xenogenic treatments to repair articular cartilage defects. TISSUE ENGINEERING PART B-REVIEWS 2009; 15:1-15. [PMID: 19063664 DOI: 10.1089/ten.teb.2008.0189] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This review examines current approaches available for articular cartilage repair, not only in terms of their regeneration potential, but also as a function of immunologic response. Autogenic repair techniques, including osteochondral plug transplantation, chondrocyte implantation, and microfracture, are the most widely accepted clinical treatment options due to the lack of immunogenic reactions, but only moderate graft success rates have been reported. Although suspended allogenic chondrocytes are shown to evoke an immune response upon implantation, allogenic osteochondral plugs and tissue-engineered grafts using allogenic chondrocytes exhibit a tolerable immunogenic response. Additionally, these repair techniques produce neotissue with success rates approaching those of currently available autogenic repair techniques, while simultaneously obviating their major hindrance of donor tissue scarcity. To date, limited research has been performed with xenogenic tissue, although several studies demonstrate the potential for its long-term success. This article focuses on the various treatment options for cartilage repair and their associated success rates and immunologic responses.
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Neer Award 2007: Reversion of structural muscle changes caused by chronic rotator cuff tears using continuous musculotendinous traction. An experimental study in sheep. J Shoulder Elbow Surg 2008; 18:163-71. [PMID: 19095462 DOI: 10.1016/j.jse.2008.09.003] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 08/04/2008] [Accepted: 09/03/2008] [Indexed: 02/06/2023]
Abstract
HYPOTHESIS Chronic rotator cuff tears are associated with irreversible architectural muscle changes and a high rate of repair failure. The changes observed in man and their irreversibility with a single stage repair can be reproduced in sheep. It was the purpose of this experiment to test the hypothesis that slow, continuous elongation of a retracted musculotendinous unit allows reversal of the currently irreversible structural muscle changes. MATERIALS AND METHODS The infraspinatus tendon of 12 sheep was released using a greater tuberosity osteotomy and allowed to retract for 4 months. Then, a new device was mounted on the scapular spine and used to extend the infraspinatus muscuculotendinous unit transcutaneously by 1 mm per day. Thereafter, the tendon was repaired back to the greater tuberosity. We assessed the muscular architecture using magnetic resonance imaging, macroscopic dissection, histology, and electron microscopy. Fatty infiltration (in Hounsfield units 1/4 HU) and muscular cross-sectional area (in % of the control side) were monitored with computed tomography at tendon release, initiation of elongation, repair, and at sacrifice. RESULTS Sixteen weeks after tendon release, the mean tendon retraction was 29 +/- 6 mm (14% of original length, P = .008). In 8 sheep, elongation was achieved as planned (group I), but in 4, the elongation failed technically (group II). The mean traction time was 24 +/- 6 days with a mean traction distance of 19 +/- 4 mm. At sacrifice, the mean pennation angle in the infraspinatus of group I was not different from the control side (29.8 degrees +/-7.5 degrees vs. 30 degrees +/-6 degrees , P = .575). In group II, the pennation angle had increased from 30 degrees +/-6 degrees to 55 degrees +/-14 degrees (P = .035). There was no fatty infiltration at the time of tendon release. After retraction, there was a significant increase in fatty infiltration of the infraspinatus muscle and a decrease of its cross-sectional area to 57% of the contralateral side (P = .0001). During traction, the degree of fatty infiltration remained unchanged (36 HU to 38 HU, P = .381), and atrophy improved to a muscle square area of 78% of the contralateral side (P = .0001) in group I. In group II, an increase of fatty infiltration was measured from 36 HU to 28 HU; however, this increase was not significant (P = .144). Atrophy did not change in group II (57-55%, P = .946). At sacrifice, the remaining muscle mass was 64% in group I and 46% in group II (P = .019). DISCUSSION Our preliminary results document, that continuous elongation of a retracted, fatty infiltrated and atrophied musculotendinous unit is technically feasible. CONCLUSION In the sheep, continuous elongation can lead to restoration of normal muscle architecture, to partial reversal of muscle atrophy, and to arrest of the progression of fatty infiltration. LEVEL OF EVIDENCE Basic science level 2; Prospective comparative therapeutic study.
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Hetherington VJ, Kawalec-Carroll JS, Nadler D. Qualitative histological evaluation of photooxidized bovine osteochondral grafts in rabbits: a pilot study. J Foot Ankle Surg 2007; 46:223-9. [PMID: 17586433 DOI: 10.1053/j.jfas.2007.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Indexed: 02/03/2023]
Abstract
Photooxidation is a treatment that can render tissue less immunogenic and resistant to enzymatic degradation, while maintaining the mechanical properties of the material. The purpose of this study was to histologically examine the biocompatibility of photooxidized bovine osteochondral grafts when implanted into the rabbit. Two holes were drilled into the patellar groove of the rabbit knee. Photooxidized bovine osteochondral grafts were implanted into the holes. As a control, 1 surgically created hole in each rabbit was left to heal naturally. The animals were killed after 12 weeks. Histological analysis of the control sites indicated that fibrocartilage had begun to regenerate in the defect. Analysis of the grafts revealed a chronic, nonspecific inflammatory reaction. Active remodeling was observed in the graft bone, with "bridging" between host and graft bone evident. The articulating surface and majority of the graft cartilage remained undamaged. In a few instances, however, there was an inflammatory response to the base of the graft cartilage, near the subchondral plate. The surface of the graft cartilage was covered by a thin layer of fibrous tissue, and no viable chondrocytes were present. In most cases, there was no fusion between host and graft cartilage. The results from this study suggest that, while a biological reaction to the grafts occurred, the bone portion of the graft appeared to be in the process of remodeling, and the majority of the graft cartilage, most significantly the articulating surface, remained intact. Photooxidized osteochondral grafts show promise for use in the repair of osteochondral defects.
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Kawalec-Carroll JS, Hetherington VJ, Dockery DS, Shive C, Targoni OS, Lehmann PV, Nadler D, Prins D. Immunogenicity of unprocessed and photooxidized bovine and human osteochondral grafts in collagen-sensitive mice. BMC Musculoskelet Disord 2006; 7:32. [PMID: 16545115 PMCID: PMC1459156 DOI: 10.1186/1471-2474-7-32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 03/17/2006] [Indexed: 11/18/2022] Open
Abstract
Background Autologous and allogeneic osteochondral grafts have been used to repair damaged or diseased cartilage. There are drawbacks to both of these methods, however. Another possible source for osteochondral grafting is photooxidized xenograft scaffolds. The purpose of this study was to evaluate the adaptive immune response to unprocessed and photooxidized xenogeneic osteochondral grafts in a collagen-sensitive mouse model. Methods Unprocessed and photooxidized bovine and human osteochondral grafts were used. The grafts were implanted subcutaneously in collagen-sensitive DBA/1LacJ mice for four or twelve weeks. ELISPOT assays were conducted with spleen cells to evaluate the number of collagen-specific T cells that produce IL-2, IL-4, IL-5 or IFN-γ. Serum was collected and ELISA assays were performed to determine the titers of collagen-specific and total IgG, IgG1, IgG2a, or IgM antibodies. Histology was conducted on the retrieved osteochondral grafts. Results Results indicated that, with respect to adaptive T cell immunity, the photooxidized bovine grafts, unprocessed human grafts and photooxidized human grafts did not induce a significant response to collagen. The unprocessed bovine grafts, however, were slightly more immunogenic, inducing a weak immune response. With respect to antibody production, the bovine grafts were less immunogenic than the human grafts. Bovine collagen-specific IgG antibodies were not induced by these grafts, but production of IgM after twelve weeks was observed with both the unprocessed and photooxidized bovine grafts. In contrast, photooxidized human osteochondral grafts induced IgG1 and IgG2a antibodies, while the unprocessed human grafts did not. Pre-existing human collagen-specific IgM antibodies were present in all mice, including sham-operated negative controls that did not receive an implant. Histological analysis revealed some degree of fibrous encapsulation and inflammatory infiltrations in both bovine and human implants, whether unprocessed or photooxidized. Conclusion Both bovine and human cartilage grafts showed weak, but clear immunogenicity in the DBA/1LacJ mice, indicating that immunogenic collagen was still contained in the grafts, even after cleaning and photooxidation. The process of photooxidation is still important in osteochondral grafting, since it stabilizes the surface of the cartilage by cross-linking the collagen fibers, and allows for immediate load bearing and joint resurfacing.
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Affiliation(s)
| | | | - Douglas S Dockery
- Ohio College of Podiatric Medicine, 10515 Carnegie Avenue, Cleveland, Ohio, 44106, USA
| | - Carey Shive
- Cellular Technology Ltd., 10515 Carnegie Avenue, Cleveland, Ohio, 44106, USA
| | - Oleg S Targoni
- Cellular Technology Ltd., 10515 Carnegie Avenue, Cleveland, Ohio, 44106, USA
| | - Paul V Lehmann
- Cellular Technology Ltd., 10515 Carnegie Avenue, Cleveland, Ohio, 44106, USA
| | - Daniel Nadler
- Centerpulse Orthopedics, Ltd., Postfach 65, CH-8404 Winterthur, Switzerland
| | - Dustin Prins
- Ohio College of Podiatric Medicine, 10515 Carnegie Avenue, Cleveland, Ohio, 44106, USA
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Hetherington VJ, Kawalec JS, Dockery DS, Targoni OS, Lehmann PV, Nadler D. Immunologic testing of xeno-derived osteochondral grafts using peripheral blood mononuclear cells from healthy human donors. BMC Musculoskelet Disord 2005; 6:36. [PMID: 15987525 PMCID: PMC1184085 DOI: 10.1186/1471-2474-6-36] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Accepted: 06/29/2005] [Indexed: 11/10/2022] Open
Abstract
Background One means of treating osteoarthritis is with autologous or allogeneic osteochondral grafts. The purpose of this study was to evaluate the innate immunological response in humans toward xeno-derived osteochondral grafts that have been partially or entirely treated by the photooxidation process. Methods The antigens tested included bovine, porcine, ovine and equine osteochondral samples that have been treated in successive steps of photooxidation. ELISPOT assays were used to evaluate the production of IL-1, IL-4, IL-6, IL-10, IL-12 and TNF-α by human monocytes in response to the antigens. Results Results indicated vigorous production of IL-1, IL-6, IL-10 and TNF-α in response to untreated bovine, porcine and equine specimens. This indicates that these samples are perceived as foreign, or stimulatory, by the human monocytes. There was no induction of IL-4 or IL-12, which is required for Th2 and Th1 immunity, respectively. In contrast, the processed bovine, porcine and equine samples did not induce significant activation of cells of the innate immune system. This occurred after the first step in processing (after cleaning in increasing strengths of ethanol). This suggests that the processing steps dramatically, if not completely, negated the immunostimulatory properties of the test sample. The results for the ovine samples indicate a reverse response. Conclusion The findings of the study suggest that photooxidized bovine, porcine or equine samples have the potential to be used as an osteochondral graft. Although the first step in processing reduced the immunological response, photooxidation is still necessary to retain the structure and mechanical integrity of the cartilage, which would allow for immediate joint resurfacing.
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Affiliation(s)
| | - Jill S Kawalec
- Ohio College of Podiatric Medicine, 10515 Carnegie Avenue, Cleveland, Ohio, 44106 USA
| | - Douglas S Dockery
- Ohio College of Podiatric Medicine, 10515 Carnegie Avenue, Cleveland, Ohio, 44106 USA
| | - Oleg S Targoni
- Cellular Technology Limited, 10515 Carnegie Avenue, Cleveland, Ohio, 44106 USA
| | - Paul V Lehmann
- Cellular Technology Limited, 10515 Carnegie Avenue, Cleveland, Ohio, 44106 USA
| | - Daniel Nadler
- Centerpulse Orthopedics, Ltd., Postfach 65, CH-8404 Winterthur, Switzerland
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El-Warrak AO, Olmstead M, Schneider R, Meinel L, Bettschart-Wolfisberger R, Akens MK, Auer J, von Rechenberg B. An experimental animal model of aseptic loosening of hip prostheses in sheep to study early biochemical changes at the interface membrane. BMC Musculoskelet Disord 2004; 5:7. [PMID: 15113432 PMCID: PMC404466 DOI: 10.1186/1471-2474-5-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Accepted: 03/03/2004] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Aseptic loosening of hip prosthesis as it occurs in clinical cases in human patients was attributed to wear particles of the implants, the response of the tissue dominated by macrophages and the production of inflammatory mediators and matrix degrading enzymes; however, the cascade of events initiating the process and their interaction regarding the time course is still open and discussed controversially. Therefore, the goal of this study was to establish an experimental animal model in sheep allowing to follow the cascade of early mechanical and biochemical events within the interface membrane and study the sequence of how they contribute to the pathological bone resorption necessary for aseptic loosening of the implant. METHODS A cemented modular system (Biomedtrix) was used as a hip replacement in 24 adult Swiss Alpine sheep, with one group receiving a complete cement mantle as controls (n = 12), and the other group a cement mantle with a standardized, lateral, primary defect in the cement mantle (n = 12). Animals were followed over time for 2 and 8.5 months (n = 6 each). After sacrifice, samples from the interface membranes were harvested from five different regions of the femur and joint capsule. Explant cell cultures were performed and supernatant of cultures were tested and assayed for nitric oxide, prostaglandin E2, caseinolytic and collagenolytic activity. RNA extraction and quantification were performed for inducible nitric oxide synthase, cyclooxygenase-2, interleukin 1, and interleukin 6. Overall differences between groups and time periods and interactions thereof were calculated using a factorial analysis of variance (ANOVA). RESULTS The development of an interface membrane was noticed in both groups at both time points. However, in the controls the interface membrane regressed in thickness and biological activity, while both variables increased in the experimental group with the primary cement mantle defect over time. Nitric oxide (NO) and PGE2 concentrations were higher in the 8.5 months group (P < 0.0001) compared to the 2 months group with a tendency for the unstable group to have higher concentrations. The same was true for collagenolytic activity (P = 0.05), but not for caseinolytic activity that decreased over time (P < 0.0001). CONCLUSION In this study, a primary cement mantle defect of the femoral shaft elicited biomechanical instability and biochemical changes over time in an experimental animal study in sheep, that resembled the changes described at the bone cement-interface in aseptic loosening of total hip prosthesis in humans. The early biochemical changes may well explain the pathologic bone resorption and formation of an interface membrane as is observed in clinical cases. This animal model may aid in future studies aiming at prevention of aseptic loosening of hip prosthesis and reflect some aspects of the pathogenesis involved.
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Affiliation(s)
- Alexander O El-Warrak
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
- CNPq, Brasilia, Brazil
| | - Marvin Olmstead
- Department of Veterinary Clinical Sciences, The Ohio State University, College of Veterinary Medicine, Columbus, OH 43210, USA
| | - Rebecca Schneider
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Lorenz Meinel
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Regula Bettschart-Wolfisberger
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Margarete K Akens
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Joerg Auer
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | - Brigitte von Rechenberg
- Musculoskeletal Research Unit, Dept. of Veterinary Surgery, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland
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von Rechenberg B, Akens MK, Nadler D, Bittmann P, Zlinszky K, Neges K, Auer JA. The use of photooxidized, mushroom-structured osteochondral grafts for cartilage resurfacing--a comparison to photooxidized cylindrical grafts in an experimental study in sheep. Osteoarthritis Cartilage 2004; 12:201-16. [PMID: 14972337 DOI: 10.1016/j.joca.2003.11.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2003] [Accepted: 11/02/2003] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This article addresses the problem of structural design with osteochondral grafts used for cartilage resurfacing. METHODS Photooxidized cylindrical or mushroom-shaped grafts were surgically implanted in the weight bearing area of the medial and lateral femoral condyles of eight sheep (condyles: N=8/group). Both types of photooxidized grafts contained no viable chondrocytes at the time of implantation. Results were evaluated at 2 and 6 months after surgical implantation of the grafts. Qualitative and quantitative evaluation of the subchondral bone area was performed using plastic embedded sections of non-decalcified bone and cartilage specimens and placing emphasis on graft anchorage, cyst-like lesions at the base of the cartilage junction and at the base of the graft in the subchondral bone region. Cartilage morphology was studied qualitatively focusing on viability of the graft and adjacent host cartilage, while a score system was developed for semi-quantitative evaluation of the overall articular cartilage performance. The semiquantitative scores and histomorphometrical measurements were subjected to statistical analysis using a factorial analysis of variance (ANOVA-test). RESULTS The photooxidized mushroom-shaped grafts developed less fibrous tissue and cyst-like lesions in the subchondral bone area at 2 and 6 months compared to the cylindrical grafts. Areas of endochondral ossification and bone remodeling were noticeable in the mushroom structured grafts at 2 months, and also bone remodeling was more complete at 6 months than with the cylindrical grafts. Increased numbers of cells were seen in the basal remodeling zones of both graft types increased from the 2 months to the 6 months specimens, but mushroom structured grafts showed better results. In both graft types, however, the midzone of the cartilage matrix was still acellular at 6 months. Cells from the subchondral bone area started to penetrate the calcified cartilage zone and tide mark at 2 months and repopulated the old photooxidized cartilage matrix already at 6 months after implantation. Cartilage repopulation was dependent on a stable subchondral bone area in both types of grafts. Matrix degradation of the adjacent host cartilage was minimal at 2 and 6 months. At 6 months a junction between host and graft cartilage was already noticed in some of the mushroom-shaped grafts. CONCLUSION This study confirmed the importance of the subchondral bone area for osteochondral graft survival. In addition it demonstrated that the structure of the graft influences considerably the architecture of the subchondral bone, and with this the possibility for the repopulation of the old cartilage matrix including the junction between the host and graft cartilage matrix.
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Affiliation(s)
- B von Rechenberg
- Musculoskeletal Research Unit, Equine Hospital, Faculty of Veterinary Medicine, University of Zurich, Zurich, Switzerland.
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Akens MK, von Rechenberg B, Bittmann P, Nadler D, Zlinszky K, Auer JA. Long term in-vivo studies of a photo-oxidized bovine osteochondral transplant in sheep. BMC Musculoskelet Disord 2001; 2:9. [PMID: 11747477 PMCID: PMC61033 DOI: 10.1186/1471-2474-2-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2001] [Accepted: 11/30/2001] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Articular cartilage has limited capacity to repair. Defects greater than 3 mm heal with formation of inferior fibrous cartilage. Therefore, many attempts have been made to find the ideal graft for larger cartilage lesions. Different grafts, such as untreated or cryopreserved osteochondral transplants, have been used with variable success. METHODS Photo-oxidized osteochondral grafts were implanted in both femoral condyles of one ovine knee. Untreated xenogeneic and autogeneic grafts served as controls. Three groups of 8 sheep each were formed and they were sacrificed 6, 12 or 18 months after surgery. RESULTS The macroscopic evaluation of the condyle and graft showed a well-maintained cartilage surface in most grafts at all time points. However, the host cartilage matrix deteriorated considerably in all xenogeneic, most autogeneic and fewer of the photo-oxidized grafts at 12 and 18 months, respectively. The blue colour of the photo-oxidized grafts resulting from the process of photo-oxidation was visible in all grafts at 6 months, had diminished at 12 months and had completely disappeared at 18 months after surgery. Histologically a loss of matrix staining was almost never noticed in untreated xenografts, transiently at 6 months in photo-oxidized grafts and increased at 12 and 18 months. Fusion between graft and host cartilage could be seen in photo-oxidized grafts at 12 and 18 months, but was never seen in autografts and xenografts. CONCLUSIONS The photo-oxidation of osteochondral grafts and its use as transplant appears to have a beneficial effect on cartilage and bone remodelling. Osteochondral grafts pre-treated with photo-oxidation may be considered for articular cartilage replacement and therefore may delay artificial joint replacements in human patients.
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Affiliation(s)
- Margarete K Akens
- Musculoskeletal Research Unit, Department of Veterinary Surgery, University of Zurich, 8057 Zurich, Switzerland
| | - Brigitte von Rechenberg
- Musculoskeletal Research Unit, Department of Veterinary Surgery, University of Zurich, 8057 Zurich, Switzerland
| | | | - Daniel Nadler
- Sulzer Orthopedics Ltd, 8401 Winterthur, Switzerland
| | - Kati Zlinszky
- Musculoskeletal Research Unit, Department of Veterinary Surgery, University of Zurich, 8057 Zurich, Switzerland
| | - Jörg A Auer
- Musculoskeletal Research Unit, Department of Veterinary Surgery, University of Zurich, 8057 Zurich, Switzerland
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