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Characterization of a Pre-Clinical Mini-Pig Model of Scaphoid Non-Union.

Behrends DA, Khendek L, Gao C, Zayed N, Henderson JE, Martineau PA - J Funct Biomater (2015)

Bottom Line: A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation.With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging.The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality.

View Article: PubMed Central - PubMed

Affiliation: Bone Engineering Labs, Research Institute-McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec H3G 1A4, Canada. domi.behrends@gmail.com.

ABSTRACT
A fractured scaphoid is a common disabling injury that is frequently complicated by non-union. The treatment of non-union remains challenging because of the scaphoid's small size and delicate blood supply. Large animal models are the most reliable method to evaluate the efficacy of new treatment modalities before their translation into clinical practice. The goal of this study was to model a human scaphoid fracture complicated by non-union in Yucatan mini-pigs. Imaging and perfusion studies were used to confirm that the anatomy and blood supply of the radiocarpal bone in mini-pigs were similar to the human scaphoid. A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation. Bone healing was assessed using quantitative micro computed tomography and histology. With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging. The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality. This model is an appropriate, easily reproducible model for the evaluation of novel approaches for the repair of human scaphoid fractures.

No MeSH data available.


Related in: MedlinePlus

Histological analysis of volar and dorsal aspects of radiocarpal bone: 60 µm sections were cut with a saw microtome from the volar and dorsal aspects of the LEFT (upper) and RIGHT (lower) radiocarpal bones, adjacent to those stained with Alizarin red in Figure 4. The sections were first visualized under fluorescence microscopy to capture images of calcein labeling before staining with TolBlue to distinguish mineralized (grey) from soft (blue) tissue. The images were then super-imposed (Calcein + TolBlue) to identify active bone-forming surfaces. Adjacent sections were stained with TRAP and Fast Green to identify osteoclasts on surfaces undergoing resorption. No differences were seen in any staining between the Volar and Dorsal aspects or between LEFT and RIGHT radiocarpal bones. Scale bars represent 100 µm for Calcein and TolBlue images and 50 µm for TRAP images.
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jfb-06-00407-f005: Histological analysis of volar and dorsal aspects of radiocarpal bone: 60 µm sections were cut with a saw microtome from the volar and dorsal aspects of the LEFT (upper) and RIGHT (lower) radiocarpal bones, adjacent to those stained with Alizarin red in Figure 4. The sections were first visualized under fluorescence microscopy to capture images of calcein labeling before staining with TolBlue to distinguish mineralized (grey) from soft (blue) tissue. The images were then super-imposed (Calcein + TolBlue) to identify active bone-forming surfaces. Adjacent sections were stained with TRAP and Fast Green to identify osteoclasts on surfaces undergoing resorption. No differences were seen in any staining between the Volar and Dorsal aspects or between LEFT and RIGHT radiocarpal bones. Scale bars represent 100 µm for Calcein and TolBlue images and 50 µm for TRAP images.

Mentions: This trend was reflected by a significant reduction in the number (Tb.N) and connectivity (Conn.Dn) of trabeculae at the osteotomy site with DF. Histological analyses of bone formation and resorption are shown in 60 µm thick bone sections from the dorsal and volar aspects of left (IF) and right (DF) radiocarpal bones (Figure 5). Dynamic labeling of bone formation with calcein, and staining of bone resorbing osteoclasts with TRAP, showed no difference between dorsal and volar aspects or RIGHT (IF) and LEFT (DF) specimens.


Characterization of a Pre-Clinical Mini-Pig Model of Scaphoid Non-Union.

Behrends DA, Khendek L, Gao C, Zayed N, Henderson JE, Martineau PA - J Funct Biomater (2015)

Histological analysis of volar and dorsal aspects of radiocarpal bone: 60 µm sections were cut with a saw microtome from the volar and dorsal aspects of the LEFT (upper) and RIGHT (lower) radiocarpal bones, adjacent to those stained with Alizarin red in Figure 4. The sections were first visualized under fluorescence microscopy to capture images of calcein labeling before staining with TolBlue to distinguish mineralized (grey) from soft (blue) tissue. The images were then super-imposed (Calcein + TolBlue) to identify active bone-forming surfaces. Adjacent sections were stained with TRAP and Fast Green to identify osteoclasts on surfaces undergoing resorption. No differences were seen in any staining between the Volar and Dorsal aspects or between LEFT and RIGHT radiocarpal bones. Scale bars represent 100 µm for Calcein and TolBlue images and 50 µm for TRAP images.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493521&req=5

jfb-06-00407-f005: Histological analysis of volar and dorsal aspects of radiocarpal bone: 60 µm sections were cut with a saw microtome from the volar and dorsal aspects of the LEFT (upper) and RIGHT (lower) radiocarpal bones, adjacent to those stained with Alizarin red in Figure 4. The sections were first visualized under fluorescence microscopy to capture images of calcein labeling before staining with TolBlue to distinguish mineralized (grey) from soft (blue) tissue. The images were then super-imposed (Calcein + TolBlue) to identify active bone-forming surfaces. Adjacent sections were stained with TRAP and Fast Green to identify osteoclasts on surfaces undergoing resorption. No differences were seen in any staining between the Volar and Dorsal aspects or between LEFT and RIGHT radiocarpal bones. Scale bars represent 100 µm for Calcein and TolBlue images and 50 µm for TRAP images.
Mentions: This trend was reflected by a significant reduction in the number (Tb.N) and connectivity (Conn.Dn) of trabeculae at the osteotomy site with DF. Histological analyses of bone formation and resorption are shown in 60 µm thick bone sections from the dorsal and volar aspects of left (IF) and right (DF) radiocarpal bones (Figure 5). Dynamic labeling of bone formation with calcein, and staining of bone resorbing osteoclasts with TRAP, showed no difference between dorsal and volar aspects or RIGHT (IF) and LEFT (DF) specimens.

Bottom Line: A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation.With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging.The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality.

View Article: PubMed Central - PubMed

Affiliation: Bone Engineering Labs, Research Institute-McGill University Health Centre, Montreal General Hospital, 1650 Cedar Ave, Montreal, Quebec H3G 1A4, Canada. domi.behrends@gmail.com.

ABSTRACT
A fractured scaphoid is a common disabling injury that is frequently complicated by non-union. The treatment of non-union remains challenging because of the scaphoid's small size and delicate blood supply. Large animal models are the most reliable method to evaluate the efficacy of new treatment modalities before their translation into clinical practice. The goal of this study was to model a human scaphoid fracture complicated by non-union in Yucatan mini-pigs. Imaging and perfusion studies were used to confirm that the anatomy and blood supply of the radiocarpal bone in mini-pigs were similar to the human scaphoid. A 3 mm osteotomy of the radiocarpal bone was generated and treated with immediate fixation or filled with a dense collagen gel followed by delayed fixation. Bone healing was assessed using quantitative micro computed tomography and histology. With immediate fixation, the osteotomy site was filled with new bone across its whole length resulting in complete bridging. The dense collagen gel, previously shown to impede neo-vascularization, followed by delayed fixation resulted in impaired bridging with less bone of lower quality. This model is an appropriate, easily reproducible model for the evaluation of novel approaches for the repair of human scaphoid fractures.

No MeSH data available.


Related in: MedlinePlus