- Email: [email protected]
Suture Fixation of Biodegradable Nanofibrous Poly-Caprolactone Scaffolds to Bovine Meniscus: A Novel Approach to Repairing Meniscal Tears (SS-48)
e24
ABSTRACTS
number of viable cells in a construct, so that they will not detach by the high fluid flow during arthroscopic implantation. Results: Cells were alive throughout the cell culture procedure. Consistency of the polymer was ideal for implantation between 7 and 9 days. The cell-encapsulated polymer was recovered after implantation and viability of cells and attachment to the co-polymer was demonstrated. Good attachment was observed by ESEM before and after implantation. Discussion: Fluid flow during arthroscopic implantation affects the attachment of chondrocytes to the copolymer. Previous attempts to deliver chondrocyte-constructs were performed and no cells attached to the polymer were observed. The encapsulation technique appears to help maintain cells within the construct, an important consideration for arthroscopic implantation.
Tissue Engineered Arthroscopic Repair of Experimental Cartilage Lesions in Horses (SS-47). Clemente Ibarra, MD, German Lombardero, Valentin Martinez, Maria Masri, MVZ, MSC, DACVIM, Blanca Garcia, MD, Baltazar Reyes, MD, and Cristina Velasquillo Objective: To valuate by means of magnetic resonance imaging (MRI), arthroscopy and histology the repair tissue obtained after the arthroscopic implantation of an autologous chondrocyte-construct derived from cartilage and seeded onto a polyglycolic acid-polylactic acid (PGA-PLA) co-polymer attached to an experimental chondral lesion in the patello-femoral joint of the horse. Materials and methods: Five young horses were used. An osteochondral biopsy was obtained from the left femoral trochlea. Chondrocytes were isolated by collagenase digestion and expanded in culture. Cells were seeded (2x107) onto PGA/PLA discs and were implanted arthroscopically to repair 8mm diameter cartilage defects created in the right medial trochlea using an absorbable fixation device. At 8 weeks stifle joints were evaluated by MRI, arthroscopy and light microscopy (H&E, Safranin-O, Trichrome). Results: New tissue was integrated to normal surrounding tissue. Arthroscopic evaluation showed cartilage-like tissue in all defects. MRI showed a distinct difference among the tissue engineered repair and controls. Histology demonstrated very cellular fibrocartilage-like repair tissue, attached to subchondral bone. Discussion: Arthroscopic implantation of cell-polymer constructs was possible. Defects were filled by cartilage-like tissue by 8 weeks. MRI was useful to evaluate
repair. The equine model is extremely useful to test new techniques for potential human use. Suture Fixation of Biodegradable Nanofibrous PolyCaprolactone Scaffolds to Bovine Meniscus: A Novel Approach to Repairing Meniscal Tears (SS-48). Neil P. Sheth, MD, Robert L. Mauck, PhD., Wan-Ju Li, PhD, Rocky Tuan, PhD, Dawn Elliott, PhD, and G. Huffman, MD, MPH Purpose: We have designed a novel biodegradable, aligned nanofibrous scaffold for augmenting the repair of meniscal tears historically considered irreparable. As a first step in this endeavor, scaffold fixation to meniscal tissue was quantified by comparing suture pull-out from scaffolds and fixation strength to the native tissue. Methods: Two suture types: monofilament (Prolene) and braided (Ticron) of equal diameter; and, two knots: horizontal mattress (HM) and -caprolacone fiber aligned and vertical mattress (VM) were investigated. Polynon-aligned meshes were produced via electrospinning. Tensile testing to failure of the suture was carried out at 0.1% elongation/second. An “apparent” Young’s modulus was calculated from the stress-strain profile and scaffold geometry. Subsequently, circumferentially aligned bovine meniscal strips were sutured parallel to aligned scaffolds using single or double VM or HM with Ticron suture. Results: The apparent Young’s modulus was 15 MPa for the aligned group sutured with a Ticron HM compared to 5 MPa for the same scaffold sutured with a Prolene HM (Figure 1, left, p⬍0.01). There was no significant difference in the tensile strength between HM and VM knots. When sutured to native meniscus, double knots provided slightly stronger fixation (Figure 1, right). Conclusion: This study confirms that aligned scaffolds have superior tensile properties compared to nonaligned scaffolds and that a braided Ticron suture material provides a more stable fixation. Moreover, increasing number of VM Ticron knots were shown to improve the fixation strength of fiber-aligned scaffolds to the native tissue. Arthroscopic Glenoid Resurfacing with a Meniscal Allograft (SS-49). William T. Pennington, MD, and Brian Bartz, PA-C Purpose: The chronically painful arthritic glenohumeral joint recalcitrant to non-surgical treatment modalities generally has been treated with an open arthroplasty type of procedure. Certain patients may benefit from a less invasive surgical technique in which a meniscal
ABSTRACTS
number of viable cells in a construct, so that they will not detach by the high fluid flow during arthroscopic implantation. Results: Cells were alive throughout the cell culture procedure. Consistency of the polymer was ideal for implantation between 7 and 9 days. The cell-encapsulated polymer was recovered after implantation and viability of cells and attachment to the co-polymer was demonstrated. Good attachment was observed by ESEM before and after implantation. Discussion: Fluid flow during arthroscopic implantation affects the attachment of chondrocytes to the copolymer. Previous attempts to deliver chondrocyte-constructs were performed and no cells attached to the polymer were observed. The encapsulation technique appears to help maintain cells within the construct, an important consideration for arthroscopic implantation.
Tissue Engineered Arthroscopic Repair of Experimental Cartilage Lesions in Horses (SS-47). Clemente Ibarra, MD, German Lombardero, Valentin Martinez, Maria Masri, MVZ, MSC, DACVIM, Blanca Garcia, MD, Baltazar Reyes, MD, and Cristina Velasquillo Objective: To valuate by means of magnetic resonance imaging (MRI), arthroscopy and histology the repair tissue obtained after the arthroscopic implantation of an autologous chondrocyte-construct derived from cartilage and seeded onto a polyglycolic acid-polylactic acid (PGA-PLA) co-polymer attached to an experimental chondral lesion in the patello-femoral joint of the horse. Materials and methods: Five young horses were used. An osteochondral biopsy was obtained from the left femoral trochlea. Chondrocytes were isolated by collagenase digestion and expanded in culture. Cells were seeded (2x107) onto PGA/PLA discs and were implanted arthroscopically to repair 8mm diameter cartilage defects created in the right medial trochlea using an absorbable fixation device. At 8 weeks stifle joints were evaluated by MRI, arthroscopy and light microscopy (H&E, Safranin-O, Trichrome). Results: New tissue was integrated to normal surrounding tissue. Arthroscopic evaluation showed cartilage-like tissue in all defects. MRI showed a distinct difference among the tissue engineered repair and controls. Histology demonstrated very cellular fibrocartilage-like repair tissue, attached to subchondral bone. Discussion: Arthroscopic implantation of cell-polymer constructs was possible. Defects were filled by cartilage-like tissue by 8 weeks. MRI was useful to evaluate
repair. The equine model is extremely useful to test new techniques for potential human use. Suture Fixation of Biodegradable Nanofibrous PolyCaprolactone Scaffolds to Bovine Meniscus: A Novel Approach to Repairing Meniscal Tears (SS-48). Neil P. Sheth, MD, Robert L. Mauck, PhD., Wan-Ju Li, PhD, Rocky Tuan, PhD, Dawn Elliott, PhD, and G. Huffman, MD, MPH Purpose: We have designed a novel biodegradable, aligned nanofibrous scaffold for augmenting the repair of meniscal tears historically considered irreparable. As a first step in this endeavor, scaffold fixation to meniscal tissue was quantified by comparing suture pull-out from scaffolds and fixation strength to the native tissue. Methods: Two suture types: monofilament (Prolene) and braided (Ticron) of equal diameter; and, two knots: horizontal mattress (HM) and -caprolacone fiber aligned and vertical mattress (VM) were investigated. Polynon-aligned meshes were produced via electrospinning. Tensile testing to failure of the suture was carried out at 0.1% elongation/second. An “apparent” Young’s modulus was calculated from the stress-strain profile and scaffold geometry. Subsequently, circumferentially aligned bovine meniscal strips were sutured parallel to aligned scaffolds using single or double VM or HM with Ticron suture. Results: The apparent Young’s modulus was 15 MPa for the aligned group sutured with a Ticron HM compared to 5 MPa for the same scaffold sutured with a Prolene HM (Figure 1, left, p⬍0.01). There was no significant difference in the tensile strength between HM and VM knots. When sutured to native meniscus, double knots provided slightly stronger fixation (Figure 1, right). Conclusion: This study confirms that aligned scaffolds have superior tensile properties compared to nonaligned scaffolds and that a braided Ticron suture material provides a more stable fixation. Moreover, increasing number of VM Ticron knots were shown to improve the fixation strength of fiber-aligned scaffolds to the native tissue. Arthroscopic Glenoid Resurfacing with a Meniscal Allograft (SS-49). William T. Pennington, MD, and Brian Bartz, PA-C Purpose: The chronically painful arthritic glenohumeral joint recalcitrant to non-surgical treatment modalities generally has been treated with an open arthroplasty type of procedure. Certain patients may benefit from a less invasive surgical technique in which a meniscal