Holding power of threaded external skeletal fixation pins in the near and far cortices of cadaveric canine tibiae.
We compared the pin-bone interfaces at the near and far cortical penetration sites of positive-profile end-threaded external fixation pins in cadaveric canine tibiae. The holding power of the pins in each cortical surface was independently measured in 21 pin-bone sections. Scanning electron microscopy (SEM) was used to compare subjectively the microstructural appearance of the pin-bone interfaces at the near and far cortical penetration sites in eight pin-bone sections. The far cortical penetration site provided greater holding power than did the near cortical site. SEM evaluation suggested more bony microfractures and debris with less pin-bone SEM evaluation suggested more bony microfractures and debris with less pin-bone interlock in the near cortical penetration sites than in the corresponding far cortical penetration sites. This study showed that after low-speed power insertion of positive-profile end-threaded pins in canine cadaveric tibiae, the near cortical penetration site contributes approximately 25% less to the overall holding power of the pin than does the far cortical penetration site.
McDonald
D E
DE
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station.
Palmer
R H
RH
Hulse
D A
DA
Neigut
J S
JS
Hyman
W A
WA
Slater
M R
MR
D000818:Animals; D001858:Bone Nails / Q000592:standards / Q000662:veterinary*; D004285:Dogs; D005592:Fracture Fixation / Q000379:methods / Q000662:veterinary*; D008422:Materials Testing / Q000662:veterinary; D008855:Microscopy, Electron, Scanning / Q000662:veterinary; D013718:Tensile Strength; D013978:Tibial Fractures / Q000601:surgery*