ABSTRACT
Cardiovascular reactions to acrylic bone cement in patients with total hip replacement are a common complication. Hypotension and arrhythmias are the most frequently observed symptoms. Elderly patients with fractures of the femoral neck constitute a special risk group. In some patients these reactions will be fatal. The mechanisms suggested to explain these reactions are embolism of air, polymer or fat, reaction to the heat, and toxic or vasodilating effects of the acrylic monomer. It may be that potentially lethal complications only occur if two or more of the predisposing factors (hypovolemia, myocardial insufficiency, arrhythmia, embolism, histamine release) are present simultaneously. We have experienced a case of complication following bone cement insertion under spinal anesthesia. This female patient was 91 years old with old myocardial infarction on EKG.
Subject(s)
Aged , Female , Humans , Anesthesia, Spinal , Arrhythmias, Cardiac , Arthroplasty, Replacement, Hip , Causality , Electrocardiography , Embolism , Femur Neck , Heart Arrest , Histamine , Hot Temperature , Hypotension , Methylmethacrylate , Myocardial Infarction , Polymers , Polymethyl MethacrylateABSTRACT
Contemporary cementing techniques improved the longevity of the cemented total hip replacement. The mechanical strength of acrylic bone cement can be changed by different handling techniques with reduction of the porosity of acrylic bone cement. The greatest improvement of the mechanical properties with reducing the porosity is that of the fatigue strength. We investigated the mechanical properties of the specimens of high viscosity, Palacos R(Merk, Darmstadt, FRG) bone cement with two mixing methods, hand and vacuum mixing. Vacuum mixing improved the ultimate tensile strength by 22.4% compared to hand mixing in previous study. For the uniaxial tension fatigue test, the specimens were cyclically loaded at a maximum stress of 25 MPa at a frequency of 2.5 Hz and to investigate the porosity, scanning electromicroscopic examination was taken in each hand mixed and vacuum mixed specimens. Scanning electromicrogram showed the vacuum mixed specimens to be the more uniform and free of small voids compared with the hand mixed specimens. The results of the fatigue test were analized using Weibull distribution of survival probability, the average number of cycles to failure was 1459±924 cycles in hand mixed specimens, in vacuum mixed specimens, 21491±14956 cycles. The average fatigue life of the vacuum mixed specimens was 15 times loanger than that of the hand mixed specimens by Weibull mean, this differene exists stastically within 95% confidence interval. We could suggest vacuum mixing technique as a method eliminating porosity in a chilled acrylic bone cement and thereby markedly improving the mechanical properties. In cemented joint replacement surgery, a vacuum mixing technique are recommended as a method of preparation of acrylic bone cement
Subject(s)
Arthroplasty, Replacement, Hip , Clothing , Fatigue , Hand , Joints , Longevity , Methods , Polymethyl Methacrylate , Porosity , Tensile Strength , Vacuum , ViscosityABSTRACT
Antibiotic-acrylic bone cement composites demonstrated antibacterial activity as a result of diffusion of antibiotic from bone cement into surrounding enviroment, accordingly, the use of antibiotic incorporation to bone cement for the prevention and treatment of infection after joint surgery replacement has been adovocated. Early report of clinical success by using antibiotic-acrylic bone cement composites are encouraging. Our authors applied this concept to the treatment of chronic osteomyelitis. Antibiotic contained with bone cement was chosen by sensitivity test on pus culture finding. Seven cases of chronic osteomyelitia treated by using antibiotic-acrylic bone eement composites were .studied in the Department of Orthopaedic Surgery, Kyung Hee University Hospital from July 1979 to March 1981. The follow-up period was from 3 months tc 22 months. The results were as follow: 1. Six cases showed no evidence of recurrence except one by using antibiotic acrylic bone cement composites. 2. The impregantion of antibiotic in acrylic bone cement shall be regarded to be effective in increasing the local antibacterial activity by leaching the antibiotic into surrounding tissue over a period continiously in treatment of chronic osteomyelitis. 3. The use of antibiotic-acrylic bone cement compositea into dead space by saucerization are consid- ered an one such approach to the decrease of dead space. 4. The impregnation of antibiotic in acrylic bone cement is regarded a new concept in treatment of chronic osteomyelitis.