[Biomechanical study on a novel injectable calcium phosphate cement containing poly (latic-co-glycolic acid) in repairing tibial plateau fractures].
OBJECTIVE
To investigate the biomechanics of a novel injectable calcium phosphate cement (CPC) composited by poly (lactic-co-glycolic acid) (PLGA) combined with double-screw fixation in repairing Schatzker II type tibial plateau fracture, so as to provide the mechanical basis for the clinical minimally invasive treatment.


METHODS
Ten matched pairs of proximal tibia specimens were harvested from 10 elderly cadavers to prepare Schatzker II type tibial plateau fracture model. Fracture was fixed by forcing injection of CPC (experimental group) or autologous cancellous bone (control group) combined with double-screw fixation. The samples underwent axial compression on MTS 858 material testing machine to measure the load-displacement, the maximum load, and compressive stiffness.


RESULTS
The novel CPC had good injectable property at room temperature, which could fill in bone defect fully and permeated into the surrounding cancellous bone. The average bone mineral density of tibial metaphysis was (0.639 +/- 0.081) g/cm2 in the experimental group and (0.668 +/- 0.083) g/cm2 in the control group, showing no significant difference (t=1.012, P=0.331). The maximum load in the experimental group [(4 101 +/- 813) N] was significantly higher than that in the control group [(692 +/- 138) N] (t=3.932, P=0.001). The compressive stiffness was (1 363 +/- 362) N/mm in the experimental group and was (223 +/- 54) N/mm in the control group, showing significant difference (t=3.023, P=0.013).


CONCLUSIONS
The novel CPC can effectively restore the biomechanical properties of tibilal plateau in repairing Schatzker II type tibial plateau fracture by means of forcing injection combining with double-screw fixation. It could be used as an effective bone substitute in the clinical application.
Department of Orthopaedics, the Fourth Affiliated Hospital of Guangzhou Medical University, Guangzhou Guangdong, 511447, P.R. China. zhz202@hotmail.com
Huazhang
H
Zou
Xiaochun
X
Ma
Cheng
C
Tang
Chuang
C
Li
Jianwei
J
Chen
Jiandong
J
Ye
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use*; D001863:Bone Screws; D016025:Bone Transplantation / Q000379:methods; D002102:Cadaver; D002130:Calcium Phosphates / Q000008:administration & dosage*; D019245:Compressive Strength; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007267:Injections; D019344:Lactic Acid / Q000008:administration & dosage; D008297:Male; D008422:Materials Testing; D011100:Polyglycolic Acid / Q000008:administration & dosage; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013978:Tibial Fractures / Q000628:therapy*; D014182:Transplantation, Autologous; D016474:Weight-Bearing
D001843:Bone Cements; D002130:Calcium Phosphates; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid