Bone cutting produces heat which macroscopically leads to charring and the formation of bone dust. As part of a project to design a novel bone cutting device, we studied the extent of histological thermal damage from bone cutting with different cutting blades. Three blades were used: a bone hacksaw made in the nineteenth century which was used for amputation, a sagittal saw blade made by Ortho Solutions, and a sagittal saw blade made by Stryker. Sheep femurs were harvested from recently euthanised animals and cuts were made with these three devices, producing ring-shaped bone specimens. Specimens were immediately stored in formaldehyde, decalcified, and stained with hematoxylin and eosin. The edge of the specimens was then photographed microscopically, and the images examined with the computer programme Axiovision (Carl Zeiss AG, Oberkochen, Germany). Visual examination allowed identification of live and dead osteocytes, and also to measure their depth from the surface. A minimal of 7 images was obtained per blade. The hacksaw specimens had the highest percentage of live osteocytes (n=214, 59.8%), and with the shortest average depth where live osteocytes were located (169μm, SD 78.15). In comparison, the percentage of live osteocytes for the Ortho Solutions (n=156, 17.4%) and Stryker (n=168, 29.5%) blades were much lower. The difference in average depths where live osteocytes were located was statistically significant between the three groups (p < 0.001). The average depths of dead osteocytes were shallowest for the Stryker (115μm, SD 67.56) and hacksaw (118.28 μm, SD 75.16) groups with no statistical difference between them. In conclusion the hacksaw appeared to produce the least thermal damage histologically during cutting. The results reflect a relationship between certain features in cutting blade designs and the extent of thermal damage. Future experiments to directly measure heat produced during cutting are planned.
Bone cutting produces heat which macroscopically leads to charring and the formation of bone dust. As part of a project to design a novel bone-cutting device, we studied the extent of histological thermal damage from different cutting blades. Three blades were used: a nineteenth century bone hacksaw, and modern sagittal saw blades manufactured by Ortho Solutions and Stryker. Sheep femurs were harvested from recently euthanised animals and cuts were made with these blades. Specimens were immediately stored in formaldehyde, decalcified, and stained with hematoxylin and eosin. The edge of the specimens was then photographed microscopically, and the images examined with Axiovision software (Carl Zeiss AG, Oberkochen, Germany). Visual examination allowed identification of live and dead osteocytes, and also to measure their depth from the surface. A minimal of 7 images was obtained per blade. The hacksaw specimens had the highest percentage of live osteocytes (n=214, 59.8%), and the shortest average depth where live osteocytes were located (169 μm, SD 78.15). In comparison, the percentage of live osteocytes for the Ortho Solutions (n=156, 17.4%) and Stryker (n=168, 29.5%) blades were much lower. The difference in average depths where live osteocytes were located was statistically significant between the three groups (p<0.001). In conclusion the hacksaw appeared to produce the least thermal damage histologically during cutting. The results reflect a relationship between certain features in cutting blade designs and the extent of thermal damage. Future experiments to monitor heat produced during cutting are planned.
Hyperlaxity is associated with a high incidence of shoulder dislocations. Collagen V regulates the diameter of fibrils of the abundant collagen type I. Decorin and biglycan are members of the small leucine rich proteoglycans(SLRP's)family and play important roles in the regulation of collagen fibrillogenesis. The aim of this study was to identify if there was a link in hyperlaxity, capsule strength, collagen V and SLRP's expression. Data was collected for 10 patients undergoing open shoulder stabilization for recurrent instability. Beighton score was used to assess hyperlaxity. Localization of Collagen V and SLRP's was studied by immunohistochemical staining of paraffin embedded sections of shoulder capsule. Grading of the stain was done on a 0-4 scale(0=no staining and 4=strong staining>50% of the slide)by three observers. Shoulder capsules were mounted on a material testing system and vertical load was applied to reach yield.Background
Methods
Hyperlaxity is associated with a high incidence of sporting injuries. Collagen V regulates the diameter of fibrils of the abundant collagen type I. Decorin and biglycan are members of the small leucine rich proteoglycans(SLRP's)family and play important roles in the regulation of collagen fibrillogenesis. The aim of this study was to identify if there was a link in hyperlaxity, tissue strength, collagen V and SLRP's expression. Data was collected for 25 patients. 12 had open shoulder stabilization and 13 had primary ACL reconstruction. Beighton score was used to assess hyperlaxity. Localization of Collagen V and SLRP's was studied by immunohistochemical staining of the paraffin embedded sections of the skin. Grading of the stain was done on a 0-4 scale(0=no staining and 4=strong staining>50% of the slide)by three observers. Tissue specimens were mounted on a material testing system and vertical load was applied to reach yield.Background
Patients and methods
