In vitro biomechanical properties of linear, circular, and hybrid external skeletal fixation devices for use in large ruminants.
OBJECTIVE
To report the biomechanical properties of 3 external skeletal fixation (ESF) devices for use in large ruminants.


METHODS
In vitro biomechanical testing of ESF constructs.


METHODS
Adult buffalo (weighing, 250-350 kg) tibiae (n=27).


METHODS
ESF constructs (bilateral linear fixator [BLF], 4-ring circular external fixator [CEF], and hybrid fixator [HF]) were made using mild (low carbon) steel implants plated with nickel and cadaveric buffalo tibiae. After ESF application, a 1 cm mid-diaphyseal gap was created. Constructs were loaded to failure, on a materials testing machine, in axial compression (n=5/ESF type) and craniocaudal bending (n=3/ESF type). In addition, 3 CEF constructs were tested in intact tibiae under craniocaudal bending.


RESULTS
In compression, HF was the strongest and most rigid construct; yield load was significantly higher for HF than for BLF or CEF. Under bending, both CEF and HF had similar strength and modulus of elasticity. Strength for BLF was higher than CEF and HF, whereas the reverse was true for modulus of elasticity.


CONCLUSIONS
ESF made from mild steel for use in large ruminants could withstand<or=300 kg load applied under compression and bending moment without any substantial adverse biomechanical effects on the constructs. HF was most rigid and strong under compression, whereas BLF was strongest in craniocaudal bending. Overall, HF seemed biomechanically the most suitable ESF device.


CONCLUSIONS
A hybrid ESF developed using mild steel is sufficiently strong and economical and may prove useful for fixation of long bone fractures in large ruminants (weighing<or=300 kg).
Singh
Gaj Raj
GR
Division of Surgery, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India.
Aithal
Hari Prasad
HP
Saxena
Rajendra Kumar
RK
Kinjavdekar
Prakash
P
Amarpal
Hoque
Mozammel
M
Maiti
Swapan Kumar
SK
Pawde
Abhijit Motiram
AM
Joshi
Hem Chandra
HC
D000818:Animals; D001696:Biomechanical Phenomena; D002020:Buffaloes / Q000293:injuries / Q000601:surgery; D002102:Cadaver; D016267:External Fixators / Q000592:standards / Q000662:veterinary*; D005592:Fracture Fixation / Q000295:instrumentation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005593:Fracture Fixation, Internal / Q000662:veterinary; D008422:Materials Testing / Q000592:standards / Q000662:veterinary*; D009532:Nickel; D013232:Steel; D013978:Tibial Fractures / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome
D013232:Steel; D009532:Nickel