Precooling of the femoral canal enhances shear strength at the cement-prosthesis interface and reduces the polymerization temperature.
Preheating of the femoral stem in total hip arthroplasty improves the cement-prosthesis bond by decreasing the interfacial porosity. The main concern, however, is the potential thermal osteonecrosis because of an increased polymerization temperature. In this study, the effects of femoral canal precooling on the characteristics of the cement-stem interface were evaluated in an experimental model for three test conditions: precooling of the femoral canal, preheating of the stem (44 degrees C), and a control in which stems were inserted at room temperature without thermal manipulation of the implant, cement, or bone. Compared to the control group, precooling of the femoral canal and preheating of the stem had similar effects on the cement-stem interface, with greater interfacial shear strength and a reduced porosity. Femoral canal precooling also produced a lower temperature at the cement-bone interface. No difference was found in the ultimate compressive strength of bone cement for the three preparation conditions. Based on this laboratory model, precooling of the femoral canal could improve shear strength and porosity at the stem-cement interface, minimize thermal injury, and maintain the mechanical strength of the cement.
Hsieh
Pang-Hsin
PH
Department of Orthopedics, Chang Gung Memorial Hospital, Kweishan, Taoyuan, Taiwan. hsiehph@adm.cgmh.org.tw
Tai
Ching-Lung
CL
Chang
Yu-Han
YH
Lee
Mel S
MS
Shih
Hsin-Nung
HN
Shih
Chun-Hsiung
CH
D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D001696:Biomechanical Phenomena; D001843:Bone Cements; D003080:Cold Temperature; D019245:Compressive Strength; D005270:Femur Head; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D011166:Porphyrins; D019919:Prosthesis Implantation / Q000295:instrumentation; D013314:Stress, Mechanical; D013997:Time Factors
D001843:Bone Cements; D011166:Porphyrins; C513117:precoproporphyrin