To determine the effectiveness of Ilizarov external fixator in the treatment of complex fractures of the tibial plateau.

From July 2006 to April 2009, we treated 10 patients with the Ilizarov fixator. Six men and four women ranging in age from 31 to 70 (mean age 56.3 years) were evaluated. All patients were preoperatively evaluated with Computed Tomography scans for better preoperative planning. Eight cases had fractures type VI according to Schatzker Classification and 2 cases type V.

In all patients fixation included pushing olive wires or simple wires and 2 to 4 frames. In 4 patients minimal invasive open reduction was performed with use of bone allograft. In 2 fractures, we combined the treatment with minimal internal fixation

There was no major complication trans- or postoperatively. The mean follow-up was 16 months (4–30). The mean hospitalization was 8 days and there were no cases of blood transfusion. Mobilization with no weight-bearing was immediately allowed, with partial weight bearing after 2 months and full weight bearing after 3 months. Three patients had minor pin tract complications. The average duration of external fixation was 120 days. All the fractures united and patients achieved full extension with more than 110 degrees of flexion.

Ilizarov circular fixation is an alternative method of treatment for these fractures when internal fixation is contraindicated due to trauma to the soft tissue, deficiency of bone stock, and bony comminution

Introduction: Osteoporosis is one of the major diseases worldwide, affecting millions of elderly people, with severe economical and medical consequences. The most commonly used method for the determination of decreased bone quality is the assessment of Bone Mineral Density, measured by dual X-ray absorptiometry (DXA). However DXA is quantitative and not qualitative index of the bone structure.

The purpose of this study was to correlate the bone mineral density measured by DXA with the mechanical properties of the femoral neck.

Materials and Methods: Bone mineral density of the proximal femur of 30 patients (27 women, 3 men) undergoing total hip displacement was estimated by DXA. The average age of these patients was 63.7 years. Patients with sort femoral neck or previous surgeries in proximal femur were excluded from the study. After hip replacement bone samples (femoral head and neck) were frozen and stored at −60 °C.

A plane bone slice with 6mm thickness was sawed of femoral neck using a double cutting saw. The exact specimen dimensions were measured using a sliding calliper with high accuracy.

All bone specimens were destructively tested on a material testing machine, in order to determine the material properties (Young’s modulus and yield stress) of the samples. The maximum available compression load was 100 kN with a load rate of 10 kN/min. The operational parameters and experimental data were fully controlled and handled by a graphical software package. Finally all data were evaluated and statistically analyzed.

Results: A strong linear correlation of bone mineral density (T-score) with maximum failure load of samples was noted (R2=0.852). No significant differences in Young’s modulus values, was found between bone samples.

Conclusions: Bone mineral density measured by DXA, although has limitations, remain a strong predictor of bone strength in the femoral neck region.

The use of polymethylmethacrylate (PMMA) bone cement loaded with antibiotics has become increasingly common in orthopaedic surgery. However, bacterial resistance in antibiotics is an increasing and emerging problem. PMMA bone cements containing different antibiotics, such as gentamicin plus vancomycin may be effective in prevention and treatment of infections (particularly from MRSA and MRSE).

The purpose of this study was to determine the in vitro elution characteristics of gentamicin and vancomycin when combined in acrylic cement.

Three groups of ten cement disks were prepared. Group I (control group) contained 0.5g of gentamicin per 40-g packet of Palacos-R+G powder. Group II contained 0.5g of gentamicin and 1g of powdered vancomycin and group III contained 0.5g of gentamicin and aqueous solution of vancomycin. Each cement disc (25mm x 20mm) was immersed in a 50-mL bath of normal saline at 37oC. Samples were taken at specific sampling intervals (1, 3, 7, 15, 30, 60, 90, 120, 150, 180 days). Antibiotic concentrations were measured using fluorescence polarisation immunoassay.

With regards to gentamicin release, high but rapidly decreasing antibiotic levels were detected within the first week and low concentration after the first month. Samples from Group II eluted significantly more gentamicin (120%–20% during the first month). The influence on the gentamicin release was significant but minor when aqueous solution of vancomycin (Group III) was added. With regards to vancomycin release, high antibiotic levels were detected within the first 3 days and low concentrations after the first week. Cement samples from Group II eluted significantly more antibiotic in comparison with samples from Group III.

Bone cements loaded with combinations of gentamicin and vancomycin are more effective in releasing gentamicin than bone cements with gentamicin as a single drug. Powdered vancomycin in cement samples has better elution characteristics in comparison with aqueous solution of vancomycin.

Introduction: The use of polymethylmethacrylate (PMMA) bone cement loaded with antibiotics has become increasingly common in the treatment of infected knee and hip arthroplasties and also as prophylaxis in primary joint replacement. However bacterial resistance in antibiotics is an increasing and emerging problem. PMMA bone cements containing different antibiotics, such as gentamicin plus vancomycin may be effective in prevention and treatment of infections (particularly from MRSA and MRSE). The purpose of this study was to determine the in vitro elution characteristics of gentamicin and van-comycin when combined in acrylic cement.

Material and methods: Three groups of six cement disks were prepared. Group I (control group) contained 0.5g of gentamicin sulphate per 40-g packet of Palacos-R+G powder. Group II contained 0.5g of gentamicin sulphate and 1g of finely powdered vancomycin and Group III contained 0.5g of gentamicin sulphate and aqueous solution of vancomycin (containing 2mL water for injection and 1g vancomycin). All discs were prepared using vacuum mixing technique. Each cement disc (25mm diameter × 20mm thick) was fully immersed in a 50-mL bath of normal saline at 37o C temperature in a covered beaker. At specific sampling intervals (1, 3, 7, 15, 30, 60, 90, 120, 150, 180 days) the discs were removed and placed in fresh 50 ml bath for 24 hours. Then a 2 mL sample of each solution was taken. Samples were frozen at −60° C until they were analyzed. Gentamicin and vancomycin concentrations were measured using fluorescence polarization immunoassay.

Results: With regards to gentamicin release, high but rapidly decreasing antibiotic levels were detected within the first week, resulting in an almost steadily low concentration by the end of the first month. Cement samples eluted significantly more gentamicin (120%-20% during the first month) when powdered vancomycin (Group II) was added. The influence on the gentamicin release was significant but minor when aqueous solution of vancomycin (Group III) was added (40%-20% during the same period).

With regards to vancomycin release, high antibiotic levels were detected within the first 3 days and low concentrations after the first week. Cement samples from Group II eluted significantly more antibiotic (80%–100%) in comparison with samples from Group III during the first days.

Gentamicin and vancomycin are detectable in measurements at 150 and 180 days samples.

Conclusions: Bone cements loaded with combinations of gentamicin and vancomycin are more effective in releasing gentamicin than bone cements with gentamicin as a single drug. The presence of powdered vancomycin in cement samples has major influence on the total gen-tamicin release in comparison with cements containing aqueous solution of vancomycin.

Introduction: Infections with multiresistant bacteria have become a serious problem in joint arthroplasty. Vancomycin and teicoplanin showed high effectiveness against multiresistant bacteria as methicillin-resistant S.epidermidis (MRSE) and methicillin-resistant S.aureus (MRSA).

Objective: The purpose of the present study was to determine the mechanical properties of Palacos R+G cement (containing gentamicin) mixed with:

i) powdered vancomycin or teicoplanin,

Material and methods: Five groups of ten cements specimens were prepared. Group I (control group) consisting of Palacos-R+G cement samples (contained 0.5g of gentamicin sulphate). Group II consisting of Palacos-R+G cement mixed with 1g of finely powdered vancomycin. Group III contained 400mg powdered teicoplanin. Group IV cement samples contained aqueous solution of vancomycin (2mL water for injection plus 1g vancomycin) and Group V contained aqueous solution of teicoplanin (2mL water for injection plus 400mg teicoplanin). All cement specimens were prepared using vacuum mixing technique. In order to examine the mechanical properties of the specimens (25mm diameter × 20mm height), impact and compression tests were applied. The impact test is a well-established method for the characterization of materials’ fatigue properties, as well as of creep behavior determination in case of porous materials. The size of the produced impression after a certain number of impacts reveals the material strength. Furthermore, the compression resistance, i.e. the Young’s modulus and the yield strength are properties that can be calculated by the compression tests.

Results: The compression tests showed that the specimens from Group III (containing 400mg of teicoplanin) had overall better mechanical properties, having approximately 10% higher Young’s modulus in comparison with specimens from Group II (containing van-comycin) and specimens from Group III (control group). Yield strength had no significant difference between the three groups. The impact test revealed a corresponding tendency, with the specimens containing 400mg of teicoplanin having the smaller impression (increased fatigue strength) when compared with specimens from the other groups.

With regards to samples from Groups IV and V (aqueous solutions of antibiotics) mechanical properties were significant deteriorated in comparison with cement samples from the other groups.

Conclusions: The experimental data showed that the addition of 400mg teicoplanin in Palacos R+G bone cement had better mechanical properties compared with addition of 1g vancomycin or than Palacos R+G cement with gentamicin as a single drug.

Aqueous solutions of antibiotics must not be added to the bone cement because they dramatically impair mechanical properties of the cement.

Percutaneous vertebroplasty is an effective procedure for the treatment of osteoporotic vertebral compression fractures, spinal metastasis and other pathologic spinal diseases. However, there has been no mention in the relevant literature of the use of percutaneous vertebroplasty for the treatment of spinal pseudarthrosis in ankylosing sponyloarthritis. A 58-year-old male with a long standing ankylosing spondylitis presented with increasing, intolerable and non-intractable back pain. There was a 16- month-old history of a non-significant minor fall. Various radiological imaging technicques showed spinal pseudarthrosis with extensive discovertebral destruction and fracture of the posterior elements at the level T11–T12. Under local anaesthesia, and through a transpedicular approach with the guidance of CT, the cannula of a large bore needle was introduced into the level of spinal pseudarthrosis. Bone cement was then instilled into the affected spinal level. Results were documented by spiral CT and with sagittal reconstructions. Extraosseous cement leakage was seen at the puncture site of the vertebra and in the epidural veins and the paravertebral vessels. However, the patient did not present any immediate or late neurological and systemic complications. Percutaneous vertebroplasty of spinal pseudarthrosis in patients with ankylosing spondylitis is an effective procedure for stabilization of the affected spine segments and pain management.