TY - JOUR
T1 - Comparison of two methods of screw fixation in periacetabular osteotomy
AU - Babis, George C.
AU - Trousdale, Robert T.
AU - Jenkyn, Thomas R.
AU - Kaufman, Kenton
PY - 2002/10/1
Y1 - 2002/10/1
N2 - The optimal method of fixation during periacetabular osteotomy is unknown. Periacetabular osteotomies were created on both sides of six whole pelves from fresh cadavers and were fixed randomly either with three long 4.5-mm cortical screws from the iliac crest to the osteotomized fragment (iliac fixation) or with two such screws supplemented by a transverse screw from the acetabular segment to the ilium (transverse fixation). Pelvis loading in simulated push-off phase of the gait cycle was accomplished using a custom-.made fixture. Linear potentiometers measured displacements at the pubic and ischial osteotomies. Fracture site stiffness was calculated from actuator force and pubic osteotomy displacement data. Displacement of the pubic osteotomy averaged 12.8 mm in the iliac fixation group and average 12.45 mm in the transverse group fixation. The ultimate loads beyond which catastrophic failure occurred were measured from 531.27 N to 1103.3 N (mean, 741.5 N) and 660.9 N to 1273.9 N (mean, 930.8 N), respectively. Effective stiffness ranged from 38.9 N/mm to 117 N/mm in the iliac fixation group (mean, 77.8 N/mm), and from 99 N/mm to 315 N/mm in the transverse construct (mean, 182 N/mm). Although the transverse screw provided statistically significantly greater local stiffness to the periacetabular construct fixation, neither type of fixation provided enough stability to allow immediate weightbearing after periacetabular osteotomy.
AB - The optimal method of fixation during periacetabular osteotomy is unknown. Periacetabular osteotomies were created on both sides of six whole pelves from fresh cadavers and were fixed randomly either with three long 4.5-mm cortical screws from the iliac crest to the osteotomized fragment (iliac fixation) or with two such screws supplemented by a transverse screw from the acetabular segment to the ilium (transverse fixation). Pelvis loading in simulated push-off phase of the gait cycle was accomplished using a custom-.made fixture. Linear potentiometers measured displacements at the pubic and ischial osteotomies. Fracture site stiffness was calculated from actuator force and pubic osteotomy displacement data. Displacement of the pubic osteotomy averaged 12.8 mm in the iliac fixation group and average 12.45 mm in the transverse group fixation. The ultimate loads beyond which catastrophic failure occurred were measured from 531.27 N to 1103.3 N (mean, 741.5 N) and 660.9 N to 1273.9 N (mean, 930.8 N), respectively. Effective stiffness ranged from 38.9 N/mm to 117 N/mm in the iliac fixation group (mean, 77.8 N/mm), and from 99 N/mm to 315 N/mm in the transverse construct (mean, 182 N/mm). Although the transverse screw provided statistically significantly greater local stiffness to the periacetabular construct fixation, neither type of fixation provided enough stability to allow immediate weightbearing after periacetabular osteotomy.
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U2 - 10.1097/00003086-200210000-00032
DO - 10.1097/00003086-200210000-00032
M3 - Article
C2 - 12360030
AN - SCOPUS:0036795676
SN - 0009-921X
VL - 403
SP - 221
EP - 227
JO - Clinical orthopaedics and related research
JF - Clinical orthopaedics and related research
ER -