Treatment of aneurysmal bone cyst]

The authors present the results of surgical treatment of 16 cases of aneurysmal bone cyst between 1998 and 2000. Age of patients at the onset of symptoms ranged from 5 to 15 years (average 11.3 years). In 12 cases the cysts were aggressive, and in 5 cases they were active (according to the capanne classification). In 12 cases the characteristic lining of the cyst was removed, curettage was performed and bone grafts were inserted into the bone cavity. In 3 cases autografts were used, in 2 cases both allografts and autografts were used, and in 7 cases only allografts were applied. Two cysts of the fibula were removed en-bloc, a cyst located in the scapule was treated with radiotherapy. In 15 cases the cyst was successfully managed surgically. While in 1 case a revision procedure was performed.     

Interlocking intramedullary nail with reaming of bone marrow cavity in treatment of tibia and femur pseudarthrosis]

The aim of this paper was to assess the results of treatment of pesudoarthrosis of the tibia and femur with reamed interlocked intramedullary nailing. A group of 17 patients with pseudoarthrosis of long bones were treated. Pseudoarthrosis were located in 10 cases in the tibia and in 7 cases in the femur. In the analysed group there were 14 male and 3 female patients (average age: 48 years). All patients were treated by locked intramedullary nailing. Complete bone union was observed in 15 cases, 1 case is still under observation (radiological signs of bone union are already evident) and in 1 case treatment failed to resolve the pseudoarthrosis. Intramedullary interlocking nailing in the treatment of long bone pseudoarthrosis give very good stability and creates very good conditions for blood vessel penetration between the bone fragments. The reaming procedure yields biologically active material that accelerates the bone union process.     

The occurrence of <Emphasis Type="Italic">Pneumocystis jirovecii</Emphasis> in people from three different age groups of Warsaw (Poland) community

The three age groups of people from Warsaw: children, young adults and elderly people were examined for the prevalence of infection with Pneumocystis jirovecii. Nested PCR was used to amplify fragment of mitochondrial large subunit rRNA of the fungus in samples of oropharyngeal swabs. Nineteen (12.8%) of the 148 examined samples were positive for DNA of P. jirovecii. The samples collected from children were more often positive than the samples from young adults (p = 0.003) or from both groups of adults (p = 0.0029). Moreover, among adults (n = 99) proportion of infected women (n = 6; 12.5%) was significantly higher than men (n = 1; 2%). Results of the research confirm the high prevalence of Pneumocystis infection in children and indirectly point out to children as a possible source of infection for older people.     

Terpolymerization of sulfur dioxide and methyl acrylate with electron donor monomers

The radical terpolymerization of sulfur dioxide and methyl acrylate with 1,3-butadiene, 2-methylpropene, propene, 1-hexene, 1-octene and vinyl chloride was studied by comparing the composition of terpolymers obtained under different reaction conditions and by analysis of ¹³C NMR spectra of selected terpolymers and copolymers. In the majority of systems studied, products are formed in which the ratio of SO₂ monomeric units to vinyl monomeric units is near to unity. The content of methyl acrylate monomeric units can change over a very wide range and depends mainly on the electron-donor properties of the vinyl monomer used, feed composition and conversion. An increase of the methyl acrylate content is also observed in many systems with a rise of the reaction temperature. The results obtained are interpreted in terms of a mechanisms involving the addition of individual monomers and reversibility of steps in which carbon-sulfur bonds are formed.     

PSO modular hip endoprosthesis--personal experiences]

Hip prosthesis reimplantation, particularly with concomitant bone destruction around the stem, leading to a total loss of mechanical properties of the joint, is a major concern of modern orthopedics. Between may 1998 and August 2000 nine reimplantation procedures were performed in our Department. All were performed with the use of the Biomet PSO system. In four cases reimplantation was performed because of aseptic loosening of the prosthesis, with massive bone destruction around the stem. In three cases surgery was necessary because of loosening of reimplanted prosthesis. In two cases PSO prosthesis was used because of intertrochanteric fracture instability concomitant with massive femoral head and intertrochanteric bone destruction. Functional assessment was based on the Merle d'Aubigne classification. On 6 points were attained before surgery and 10 points--6 months post-up, the difference resulting from a decrease of pain. Luxation of the prosthesis was noted in two cases one 15 days after surgery and the other one 6 months post-up. In our opinion use of PSO endoprosthesis is a very valuable method of treating cases with bone destruction of the femur following loosening of hip prosthesis.     

Percutaneous vertebroplasty in the treatment of diseases causing vertebral bone loss

Background. Percutaneous vertebroplasty involves the injection of acrylic surgical cement into the vertebral body. The basic principles of vertebroplasty and the authors' own clinical experiences are described. Material and methods. Between November 1999 and January 2005 the authors performed percutaneous vertebroplasty on 75 patients: 45 with osteoporotic compression fractures, 15 with angiomas of the vertebral bodies, and 12 patients with spinal neoplasms. There were also 3 patients with coexisting spinal angiomas and osteoporotic compression fractures. All these patients were treated under local anesthesia. Cement injections were realized by the transpedicular approach under fluoroscopic guidance; in certain cases a CT-guided approach was used. The clinical outcome was assessed based on follow-up examinations, the Oswestry questionnaire, and the Visual Analog Pain Scale. Plain x-rays or CT scans were made for purposes of radiological evaluation. Results. Follow-up examinations revealed pain relief or significant reduction of pain in 89% of the patients. In 2 cases (3%) vertebroplasty was complicated by intracanal leakage of cement. Conclusions. Percutaneous vertebroplasty is well tolerated by patients. Filling with cement is effective in the treatment of osteoporotic compression fractures and of vertebral angiomas.     

Evaluation of axial and flexural stresses in the vertebral body cortex and trabecular bone in lordosis and two sagittal cervical translation configurations with an elliptical shell model

BACKGROUND: Osteoarthritis and spinal degeneration are factors in neck and back pain. Calculations of stress in clinically occurring configurations of the sagittal cervical spine are rare. OBJECTIVE: To calculate and compare combined axial and flexural stresses in lordosis versus cervical configurations in anterior and vertical sagittal head translated positions. DESIGN: Digitized measurements from lateral cervical radiographs of 3 different shapes were used to calculate axial loads and bending moments on the vertebral bodies of C2-C7. METHODS: An elliptical shell model was used to model horizontal cross-sections of the vertebral bodies of C2 through T1. Axial and flexural stresses were calculated with short compression block equations. Elliptical shell modeling permitted separation of stresses into cortical and inner medullary regions. Digitized radiographic points were used to create polynomials representing the shape of the sagittal cervical curvatures from C1 to T1. To calculate bending moments at each vertebral segment, moment arms from a vertical line through C1 were determined from digitizing. RESULTS: Compared with the normal lordosis, stresses on the anterior vertebral body cortical margins of C5-T1 in the sagittal translated postures are compression rather than tension. At the posterior vertebral bodies in the anteriorly translated position and vertically translated postures, the stresses change from compression to tension at C5 through T1. In absolute value (ABS) compared with values at the same segments in a normal lordosis, the magnitude of the combined anterior stresses in the sagittal postures are higher at C5-C7 (eg, ABS[sigma(straight)/sigma(normal)] approximately 1.25 to 4.25). CONCLUSIONS: Vertebral body stresses are reversed in direction at C5-T1 in sagittal translated postures compared to a normal lordosis. Stress analysis, with implications for bone remodeling, indicates that both sagittal head translation postures, anterior head carriage, and vertical head translation, are undesirable configurations in the cervical spine.     

Hospital infections in the Orthopedics and Traumatology Department of a large multi-department specialized hospital

Background. Hospital infections continue to be one of the most important medical problems, especially in departments where surgical operations are performed. Materials and methods. In the year 1996, 173 microbiological tests were performed in the Orthopedic Clinic, while 1,114 tests were performed in the year 2000. Results. The most commonly isolated microorganism from hospital infections in our Orthopedic Clinic is Staphylococcus aureus, which in the year 2000 accounted for 23.13% of all positive results. Infections were most commonly incurred at or around the point of operation or in the urinary tract. During the period in question the co-efficient of hospital infections was 6.32% in 1996, 8.27% in 1997, 5.48% in 1998, 8.28% in 1999, and 7.23% in 2000. Conclusions. Reducing this coefficient, despite the increased number of hospitalizations and operations, was made possible by a number of factors, including constant monitoring and registration of hospital infections.