TY - JOUR
T1 - Mechanical evaluation of external skeletal fixatorIntramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis)
AU - Van Wettere, Arnaud J.
AU - Redig, Patrick T.
AU - Wallace, Larry J.
AU - Bourgeault, Craig A.
AU - Bechtold, Joan E.
PY - 2009/12
Y1 - 2009/12
N2 - Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: 1) varying the fixation pin position in the proximal bone segment and 2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n 24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.
AB - Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: 1) varying the fixation pin position in the proximal bone segment and 2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n 24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.
KW - Avian
KW - Biomechanics
KW - Buteo jamaicensis
KW - External skeletal fixatorintramedullary pin tie-in
KW - Orthopedic surgery
KW - Red-tailed hawk
UR - http://www.scopus.com/inward/record.url?scp=76749146911&partnerID=8YFLogxK
U2 - 10.1647/1082-6742-23.4.277
DO - 10.1647/1082-6742-23.4.277
M3 - Article
C2 - 20235458
AN - SCOPUS:76749146911
SN - 1082-6742
VL - 23
SP - 277
EP - 285
JO - Journal of Avian Medicine and Surgery
JF - Journal of Avian Medicine and Surgery
IS - 4
ER -