Biomechanical comparison of three types of internal fixation in a type C zone II pelvic fracture model.
OBJECTIVE
This study aimed to compare the stability of Tile C pelvic fractures fixed with two iliosacral (IS) screws, tension band plate (TBP), and minimally invasive adjustable plate (MIAP).


METHODS
Six embalmed specimens of adult pelvis were used. The soft tissue was removed from the specimens, but spines from the fourth lumbar vertebra to the proximal one-third of both femurs were retained. The pubic symphysis, bilateral sacroiliac joints and ligaments, bilateral hip joints, bilateral sacrotuberous ligaments, and bilateral sacrospinous ligaments were intact. Tile C pelvic fractures were created on the specimens. The symphysis pubis was fixed with a plate, and the fracture on the posterior pelvic ring was fixed with three types of internal fixation in a randomized block design. The specimens were placed in a biomechanical machine at a standing neutral posture. A cyclic vertical load of up to 500N was applied, and displacement was recorded. Shifts in the fracture gap were measured by a grating displacement sensor.


RESULTS
Under different vertical loads, the shift in the fracture gap and displacement of the pelvic fractures fixed with two IS screws were similar to those in fractures fixed with MIAP. However, the shift in the fracture gap and displacement of fractures fixed with MIAP was significantly smaller than those of fractures fixed with TBP.


CONCLUSIONS
The stability of the Tile C pelvic fractures fixed with MIAP was similar to that of fractures fixed with IS screws. MIAP performed better than TBP under vertical load.
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Tao
T
Wu
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Wei
W
Chen
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Xu
X
Li
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Qi
Q
Zhang
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Hong-Zhi
HZ
Lv
Emergency Center of Trauma, Key Laboratory of Orthopaedic Biomechanics of Hebei Province, The Third Hospital of Hebei Medical University, Orthopaedic Research Institution of Hebei Province Shijiazhuang 050051, China.
Ying-Ze
YZ
Zhang
Pelvis; biomechanics; internal fixation; unstable