Biomechanical comparison of two stabilization techniques for unstable sacral fractures.
OBJECTIVE
The purpose of the study was to assess the stability provided by an ilio-iliac dorsal plate fixation technique using an AO narrow DCP on the pelvic brim in vertically and rotationally unstable type-C pelvic ring injuries.


METHODS
We examined 12 fresh cadaver pelvises in a single limb stance load. A type-C pelvic ring injury (a type I lateral sacral fracture in the classification of Denis with symphysis pubis rupture) was performed on the cadaver specimen and fixed with a four-hole narrow dynamic compression plate to stabilize the symphysis pubis rupture; the sacrum fracture was stabilized either anteriorly with two 3-hole reconstruction plates ("anterior plate osteosynthesis") or with a posterior fixation using a 12-hole narrow DCP. A cyclic load of between 100 and 250 N was applied to the fifth lumbar vertebra of the specimen. An extensometer was attached to both sides of the sacrum fracture to detect movements at the fracture site.


RESULTS
We were able to achieve usable measurements in nine specimens. Three measurements were performed on each specimen, and the movements recorded at the fracture gap in trans-sacral plate fixation were higher than or similar to those observed for anterior plate synthesis in 23 out of 27 cases.


CONCLUSIONS
Dorsal ilio-iliac bridge plate fixation provides somewhat reduced stability compared to anterior plate fixation, but the difference is not significant.
Trauma Center Péterfy Hospital, Budapest, Hungary. bodzaytamas@freemail.hu
Tamás
T
Bodzay
János
J
Szita
Sándor
S
Manó
László
L
Kiss
Zoltán
Z
Jónás
Sándor
S
Frenyó
Zoltán
Z
Csernátony
D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D005260:Female; D005592:Fracture Fixation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012447:Sacrum / Q000293:injuries* / Q000601:surgery*; D016103:Spinal Fractures / Q000601:surgery*