Impregnated Bone Cement Research Articles

Deep Infection after Total Knee Arthroplasty

Purpose : To analyze the infection rate and its influencing factors in total knee arthroplasty (TKA), and to evaluate the results of various treatment methods for infected TKA. Materials and Methods : In 1,284 patients, 1,892 TKAs, we analyzed the infection rate (overall, according to the age, sex, date, initial diagnosis, prosthesis type, with or without bone cement and antibiotic impregnated bone cement) and the results according to treatment method. Results : Deep infection occurred in eighteen knees (0.95%); males two (1.1%) of 180, females in sixteen (0.9%) of 1,712; degenerative osteoarthritis in fifteen (1.03%) of 1,452, rheumatoid arthritis in two (1.1%) of 328; antibiotic-impregnated cemented TKAs in three (0.2%) of 1,243, cemented TKAs without using antibiotics in fifteen (4.5%) of 337, noncemented TKAs in two (0.64%) of 312. One of the seven two-stage reimplantations relapsed at a postoperative two years and nine months and then fused. Conclusion : The overall infection rate was 0.95%. No statistically significant difference was observed between the incidence of infection according to sex, prosthesis type or initial diagnosis (p>0.01). Infection rate was significantly lower in antibiotic-impregnated cemented TKAs (p

THE DEVELOPMENT OF A UNIQUE MANUFACTURING DEVICE TO PRODUCE A "STRING-OF-PEARLS" ANTIBIOTIC DELIVERY DEVICE FOR MASSIVE SOFT TISSUE DEFECTS

Trauma victims suffering massive soft tissue wounds are at increased risk for infection. This is typically addressed by placing antibiotic impregnated bone cement into the tissue defect to provide a massive prophylaxis directly to the affected site. The cement–antibiotic mixture is typically "pasted" onto a length of suture by the surgeon. Unfortunately, this process is sometimes difficult to perform in the operating room environment due to difficulty in localizing the mixture on the suture. In addition, the surgeon must perform the process within a relatively short time constraint as the mixture hardens. In the current study we address this issue by proposing a unique molding design which is lightweight, cost effective, disposable, and suitable for use in the operating room environment.

Cytotoxic effect of methotrexate and its solvent on osteosarcoma cells in vitro

Bone tumours may recur locally even after wide surgical excision and systemic chemotherapy. Local control of growth may be accomplished by the addition of cytostatic drugs such as methotrexate (MTX) to bone cement used to fill the defect after surgery and to stabilise the reconstructive prosthesis. We have studied the elution kinetics of MTX and its solvent N-methyl-pyrrolidone (NMP) from bone cement and their biological activities in five cell lines of osteosarcoma and in osteoblasts, and compared them with the effects of the parent compounds alone and in combination. Our findings show that MTX is released continuously over months at concentrations highly cytotoxic to osteosarcoma cells and suggest that the impregnated bone cement would be effective in the long term. Proliferating osteoblasts, however, were much less sensitive towards MTX. The dose-response relationship for NMP and experiments with MTX/NMP-mixtures show that the eluted concentrations of solvent are not toxic and do not influence the effects of MTX. We suggest that bone cement containing MTX dissolved in NMP releases the drug in a suitable and effective way and may be of value in the treatment of bone tumours.

Hydroxyapatite impregnated bone cement: in vitro and in vivo studies

Hydroxyapatite (HA) particle impregnated polymethylmethacrylate (PMMA) bone cement was fabricated in order to induce bony tissue ingrowth into the pores left behind by resorption of the HA. The amount of HA was 0%, 10%, and 30% by weight. After mixing the HA with bone cement it was cast in a 4 mm inside diameter glass tube (10 mm long). Each specimen was cut into half and used for in vitro and in vivo experiment. Diametral tensile and flexural bend tests were made to evaluate its mechanical properties. SEM (scanning electron microscope) and ESCA (electron spectroscopy for chemical analysis) were used to evaluate the surface characteristics of the specimen. Push-out test and histology studies were made after implanting the specimens for six weeks in the distal portion of rabbit femur. The mechanical test results showed significant decrease of the flexural and diametral tensile strength linear with the increased amount of HA (p < 0.05). The SEM and ESCA analyses showed no definite exposure of HA particles on the surface of the specimens due to the covering by PMMA. The interfacial shear strength of the implanted specimens showed significant increases in the 30% HA specimens compared with the 0% ones but the 10% specimens did not show any difference. Histological observation showed little HA particle apposition to new bone in 10% specimens but more in the 30% ones. In conclusion, this study showed the decreased mechanical properties both by increasing the amount of HA particles and with the bone particles impregnated bone cement. In vivo study showed much lower interfacial shear strength due to implant site compared to other studies but the 30% HA specimens showed statistically significant increase in the push-out strength after implanting into the distal end of rabbit femora.

Advanced and controlled drug delivery systems in clinical disease management.

Advanced and controlled drug delivery systems are important for clinical disease management. In this review the most important new systems which have reached clinical application are highlighted. Microbiologically controlled drug delivery is important for gastrointestinal diseases like ulcerative colitis and distally localized Crohn's disease. In cardiology the more classic controlled release systems have improved patient compliance and decreased side effects. In the treatment of intractable pain the spinal and transdermal route is well documented. In neurology the flattened peak-through levels of antiepileptic drugs and anti Parkinson's drugs represents a more predictable kinetic profile. Tracheal delivery of corticosteroids and sympaticomimetics in asthma and Chronic Obstructive Pulmonary Disease is fully accepted in clinical practice: delivery by this route results in better efficacy and a better safety profile. In gynaecology the delivery of pulsatile hormones (LHRH) is used for pregnancy induction, while transdermal oestrogens are promising in the prevention of osteoporosis. In surgical practice the use of antibiotic impregnated bone cement and antibiotic impregnated biodegradable collagens is well established. To prevent infections intravascular catheters coated with heparin or antibiotics are used. In ophthalmology the Ocusert systems provide a controlled release of different drugs in the eye. Most spectacular is the clinical introduction of the first liposomal drugs; amfotericine B and daunorubicine. Liposomal formulations of these drugs have enhanced activity and decreased toxicity compared to conventional formulations.

Experimental implant-related osteomyelitis induced withStaphylococcus aureus

Experimental knee-implant infection was induced in the rabbit knee with a strain (1369,phage type 85,a laboratory strain) of Staphyloccus aureus. The experimental model was adapted from an experimental study in rabbits by Gudmund Blomgren, 1981. In these experiment's osteomyelitis was induced with an noculum of 100,000 bacteria in the tibia and femur. In one series we used gentamicin impregnated bone cement and in the other series dicloxacillin was given intravenously. The controlgroup, four rabbits had no supplemental antibiotics. The animals were monitored by clinical observation, microbiological, histological and antibody methods. Only in the controlgroup without supplemental antibiotics we would see manifest inflammation around the prosthesis with increased antibody titre. With supplemental antibiotics no bacteria was found around the prosthesis.The gentamicin concentration was measured in bone from femur, tibia and from the jointfluid. A high level of gentamicin was found in the bone but not in the joint fluid. The animal model was excellent to create a model for human total joint replacement to study the dissemination of localy and intravenously injected bacteria to the artificial joint. The use of either systemic or locally administered antibiotics as prophylaxis avoided development of infection.

The Histology and Biomechanical Study of the Effect of Hydroxyapatite Impregnated Bone Cement Implanted in Rabbit Femur

The Histology and Biomechanical Study of the Effect of Hydroxyapatite Impregnated Bone Cement Implanted in Rabbit Femur

Antistaphylococcal activity of antibiotic impregnated bone cement

Infections following total knee arthroplasty constitute a devastating problem and represent a difficult obstacle for surgeons in the treatment of these patients. This study was performed in order to evaluate the in vitro antibacterial activity of bone cement impregnated with five different antibiotics effective against staphylococci and to measure the elution of these antibiotics from the cement. The determination of the in vitro activity was performed immediately, 24, 48, 72 h, 4, 5, 6 and 7 days after the preparation of the impregnated cement. All the agents tested in our study maintained bioactivity after incorporation in bone cement and eluted readily into surrounding medium. The results indicate that the glycopeptides diffuse from bone cement in therapeutic concentrations.

Local antibacterial therapy for the management of orthopaedic infections. Pharmacokinetic considerations.

Bone infection has long been a formidable foe of orthopaedic surgeons. The standard method of treating osteomyelitis generally consists of irrigation and debridement supplemented by pre- and postoperative antibiotics and intraoperative antimicrobial solutions. In the 1970s, Buchholz introduced the concept of local antibacterial therapy in the form of antibiotic impregnated bone cement to treated infected arthroplasties. From this, antibiotic impregnated beads were developed to treat local infections of bone and soft tissue. The advantage of these beads compared with parenteral therapy is that they deliver a high concentration of antibacterial locally while avoiding high systemic concentrations, thus avoiding adverse effects that are often associated with parenteral antibacterial therapy. Additionally, methylmethacrylate bone cement does not significantly affect the immune response of the body. This makes the use of antibiotic-impregnated polymethylmethacrylate (PMMA) beads highly effective either as an alternative to, or in conjunction with, systemic antibiotic treatment of infected arthroplasties, and localised bone and soft tissue infection. This article explores the indications for the use of local therapy as well as any advantages or disadvantages it may have over systemic antibacterial treatment. Additionally, there are important pharmacokinetic considerations for the optimal use of antibacterial agents in the treatment of osteomyelitis.

Prophylaxis against infection in orthopaedic practice

Prophylaxis against surgical infections is based upon reducing the number of microorganisms which access the wound, and on augmenting normal host defence mechanisms. There is no reason to challenge the importance of the principles of asepsis or of wound excision following injury. The last two decades have seen the growth of prophylaxis using antimicrobial agents and ultra-clean air systems. Although the available data offer less support for their effectiveness than might be supposed from the general acceptance of these measures, it is concluded that use of short-term systemic antibiotic prophylaxis against wound infection is currently justified in open fractures and whenever implants are being inserted. As coagulase negative staphylococci develop increasing resistance to routinely used systemic agents, the use of antibiotic impregnated bone cement appears logical. The case for ultra clean air laminar airflow systems as a cost effective means of reducing infection rates is, despite its plausibility, controversial at the present time.

Antibiotic impregnated orthopaedic bone cement: Kinetics and impact of teicoplanin on staphylococcal colonization

Previous studies in our laboratory have questioned the efficacy of antibiotic impregnated bone cement to prevent staphylococcal colonization of orthopaedic implants following surgery. Teicoplanin a glycopeptide antibiotic with excellent anti-staphylococcal activity was added to polymethylmethacrylate in concentrations ranging from 2-5 wt%. Five staphylococcal strains recovered from orthopaedic implant infections were chosen for study: 2-Staphylococcus aureus and 3-Staphylococcus eoidermidis. Two of the staphylococcal isolates were identified as producing an exopolysaccharide slime following alcian blue staining with lysine. The in vitro release of antibiotic from the resin surface was determined by biological assay at 0, 12, 24, 48, 96 and 10 days post-study. Mean teicoplanin concentrations ranged from 200 to 430 ug/ml at 0 hour and 22 to 50 ug/ml at 10 days post-study. Teicoplanin impregnated and drug free resin controls were exposed to standardized inoculum (5.0 log10 colony forming units/ml) of the staphylococcal clinical isolates and incubated at 35°C in physiologic buffered saline with 0.25% dextrose.

Effect of Bone Mineral Particles on the Porosity of Bone Cement

Bone particle-impregnated bone cement is investigated in vitro, which could be used to improve fixation between bone and cement interface by ingrowth of tissues that may replace bone particles. Inorganic bone particles (150-300 microns diameter) were mixed with regular bone cement powder by 0, 10, 20, and 30% by weight and implanted into the pre-drilled intramedullary canal (11cm long, 10mm diameter) of canine femur. A 4mm diameter, 10mm long stainless steel rod was implanted to simulate the prosthesis. The specimens were cut into 2mm thick discs transversely along the long axis of the bone and ground to examine with a confocal laser microscope. Diametral tensile strength tests were performed for the 0, 10, 20, and 30% bone particle impregnated bone cement discs without the intramedullary implant. Present results show that mixing bone particles with bone cement decreased the number of pores and porosity but increased the size of pores. The analysis of porosity distribution showed no significant difference between bone cement and bone particle-impregnated bone cement. Also, the strength of the bone particle-impregnated bone cement decreased linearly with increased amount of bone particles in spite of the decreased percent porosity. Using a bone particle-impregnated bone cement along with a pre-coated implant could be one of the solutions to the problems in the fixation of total joint arthroplasty.

Antibiotic Impregnated Bone Cement in Total Hip Arthroplasty

A prospective in vivo quantification was performed to measure the elution of tobramycin and vancomycin antibiotics from two commonly used bone cements. Forty patients were divided into four groups: Group I, tobramycin-Simplex; Group II, tobramycin-Palacos-R; Group III, vancomycin-Simplex; and Group IV, vancomycin-Palacos-R. Antibiotic levels were measured from hemovac wound drainage, urine, and serum and compared with control groups who received either intravenous tobramycin or vancomycin. There were no significant differences in daily mean tobramycin levels in hemovac samples between Groups I and II. Tobramycin hemovac levels from Groups I and II were significantly higher than the tobramycin control group. Similarly, no differences were seen in daily mean vancomycin levels of the hemovac samples between Group III and IV; however, the intravenous vancomycin control group had significantly higher levels in the hemovac fluid than Groups III or IV. Tobramycin in the hemovac fluid from Groups I and II was highly bioactive against the control organism. Vancomycin in the hemovac fluid from Groups III and IV had variable bioactivity against the control organism. In 30% of the cases, no vancomycin was detected in the hemovac fluid, and in these cases, the hemovac fluid had no effect on the control organism. Tobramycin elutes to give adequate local tissue levels and releases antibiotic effects when used in an antibiotic bone cement combination. Vancomycin has variable elution properties and is not a predictable additive for the bone cements tested.

Inorganic bone and demineralized bone matrix impregnated bone cement: A preliminary in vivo study

Inorganic bone and demineralized bone matrix impregnated bone cement: A preliminary <i>in vivo</i> study

In Vitro Study of Release of Antibiotics in the Antibiotic Impregnated Bone Cement

In Vitro Study of Release of Antibiotics in the Antibiotic Impregnated Bone Cement

Orthopedic prosthesis fixation.

The fixation of orthopedic implants has been one of the most difficult and challenging problems. The fixation can be achieved via: (a) direct mechanical fixation using screws, pins, wires, etc.; (b) passive or interference mechanical fixation where the implants are allowed to move or merely positioned onto the tissue surfaces; (c) bone cement fixation which is actually a grouting material; (d) biological fixation by allowing tissues to grow into the interstices of pores or textured surfaces of implants; (e) direct chemical bonding between implant and tissues; or (f) any combination of the above techniques. This article is concerned with various fixation techniques including the potential use of electrical, pulsed electromagnetic field, chemical stimulation using calcium phosphates for the enhancement of tissue ingrowth, direct bonding with bone by glass-ceramics and resorbable particle impregnated bone cement to take advantages of both the immediate fixation offered by the bone cement and long term fixation due to tissue ingrowth.

Diagnosis and Management of the Infected Total Joint Arthroplasty

The preoperative diagnosis of the infected orthopedic implant is complicated by lack of a single precise test to forewarn patient and surgeon of the presence of microorganisms. Given the overall limitation of accuracy of preoperative diagnosis to approximately 80% when 111In scanning, preoperative aspiration, and ESR are considered, it would seem prudent to approach each revision surgery with the possibility in mind of subclinical sepsis as the cause for failure of the implant. The essentials of surgical technique including thorough debridement of the wound and removal of all existing foreign bodies, especially including PMMA bone cement, are critical to minimizing the risk for occurrence or persistence of sepsis. Although the use of antibiotic impregnated bone cement may enhance the treatment of orthopedic sepsis, the data available to date lead to the conclusion that two-stage revision surgery in the face of known sepsis remains the cornerstone of surgical therapy for the infected implant, along with aggressive and rational antibiotic treatment. The surgeon is offered the following guidelines in the management of the septic total hip arthroplasty. 1. Preoperative evaluation including ESR, 111In WBC scan, and aspiration for culture and sensitivity (fluoroscopically guided for the hip) will produce on average approximately 80% accuracy. 2. Intraoperative cultures at the time of revision surgery should be obtained prior to administration of systemic antibiotics; three tissue specimens (hip capsule, femoral membrane, acetabular membrane) should be submitted for culture and sensitivity determination. 3. Careful debridement of the surgical site of granulation tissue and all foreign bodies (e.g., PMMA) should be performed within the limits of patient safety to maximize the likelihood of success.(ABSTRACT TRUNCATED AT 250 WORDS)

Flexural properties of vacuum mixed antibiotic impregnated bone cement

Flexural properties of vacuum mixed antibiotic impregnated bone cement

A Study on The Antibacterial Effect of antibiotic Impregnated Bone Cement

A Study on The Antibacterial Effect of antibiotic Impregnated Bone Cement