Fixation of the fully hydroxyapatite-coated Corail stem implanted due to femoral neck fracture: 38 patients followed for 2 years with RSA and DEXA

Background Today, dislocated femoral neck fractures are commonly treated with a cemented hip arthroplasty. However, cementing of the femoral component may lead to adverse effects and even death. Uncemented stems may lower these risks and hydroxyapatite (HA) coating may enhance integration, but prosthetic stability and clinical outcome in patients with osteoporotic bone have not been fully explored. We therefore studied fixation and clinical outcome in patients who had had a femoral neck fracture and who had received a fully HA-coated stem prosthesis. Patients and methods 50 patients with a dislocated femoral neck fracture were operated with the fully HA-coated Corail total or hemiarthroplasty. 38 patients, mean age 81 (70-96) years, were followed for 24 months with conventional radiographs, RSA, DEXA, and for clinical outcome. Results 31 of the 38 implants moved statistically significantly up to 3 months, mainly distally, mean 2.7 mm (max. 20 mm (SD 4.3)), and rotated into retroversion mean 3.3 (-1.8 to 17) (SD 4.3) and then appeared to stabilize. Distal stem migration was more pronounced if the stem was deemed to be too small. There was no correlation between BMD and stem migration. The migration did not result in any clinically adverse effects. Interpretation The fully hydroxyapatite-coated Corail stem migrates during the first 3 months, but clinical outcome appears to be good, without any adverse events

The Elite-Plus stem migrates more than the flanged Charnley stem: A clinical, radiographic, and radiostereometric analysis of 114 patients with an average of 7 years follow-up

Background and purpose The Charnley Elite-Plus stem was introduced in 1993 as a presumed improvement of the flanged Charnley stem. We started this study in 1996 to investigate the migratory pattern of the Elite-Plus stem. Patients and methods We followed 114 patients with osteoarthritis and a primary total hip replacement with the Elite-Plus stem. Mean age at the time of operation was 64 (50-76) years. The mean follow-up time was 6.5 (2-7) years. Radiographs were evaluated with respect to cementing technique, migration, and wear measured by radiostereometry (RSA). Results The stem survival was 98% (CI: 96-100) at 7 years and 92% (CI: 86-97) at 10 years. Mean migration of the femoral head was 0.35 mm (SD 0.3) medially, 0.51 mm (SD 0.6) distally, and 1.1 mm (SD 1.8) in the dorsal direction. Mean total point motion was 1.7 mm (SD 1.7). The migration of the stems stabilized after 5 years in the medial and dorsal directions, but continued to subside slightly. Migration along any of the axes was higher if the cementing technique was inferior. Interpretation Patients with a Charnley Elite-Plus stem and defects in the cement mantle or other signs of inferior implantation technique should be carefully monitored

Simulation of Nodule-Like Pathology in Radiographs of the Lumbar Spine.

For the evaluation of the imaging properties of medical radiographic systems there are well-established standards for measuring techniques available, e.g. ISO 9236 for the measurement of the H/D curve. However, such measuring techniques require sophisticated equipment which is not available in a clinical environment. For a clinical routine of image evaluation, techniques like contrast-detail diagrams or the visual inspection of radiographs of grid pattern with varying contrast and spatial resolution are very common. The disadvantage of these techniques is that the corresponding results are very hard to be transferred to real patient images. Therefore, observer studies on the detection of certain pathology are commonly used to e.g. investigate the influence of different radiographic techniques on diagnostic image quality. As it is very difficult to find a sufficient number of patients with real pathologies for such studies, the pathologies are often simulated by fixing e.g. aluminium disks or other nodule-like objects to healthy volunteers when the radiograph is produced. This approach is relatively simple and rather successful in chest imaging. For lumbar spine images, however, the situation is different because nodule-like tumours cannot only consist of bony material which is increasing the X-ray absorption, but tumours can also destroy the bone material resulting in an increased transparency of the corresponding anatomical region. Such a behaviour is extremely hard to be simulated by fixing an external object to the patient. However, it can be easily simulated in a computer and applied to digital radiographic data. The current paper presents a computer model for the simulation of nodules in lumbar spine images. The model has been applied within a CEC founded research project, which was investigating the influence of MTF and noise power spectra on the diagnostic quality of radiographs of the lumbar spine

A comparison between IEEC, a new biodegradable particulate contrast medium, and iohexol in a tumor model of computed tomography imaging of the liver

RATIONALE AND OBJECTIVES. Higher contrast between normal and pathologic tissues in the liver may enable detection of smaller lesions in computed tomography (CT). This can be obtained using a liver-specific contrast medium. The authors evaluate a new agent, IEEC (1'-Ethyloxycarbonyloxy)-ethyl-5-acetylamino-3-(N-methyl-acetylami no)-2,4,6- triiodo-benzenecarboxylate), in an animal model, as a potential contrast agent for CT scanning of the liver. The IEEC particulate contrast medium used is based on a prodrug ester design of metrizoic acid and accumulates rapidly in the liver. The particles are quickly degraded into well-known metabolites and excreted from the body. METHODS. Two groups of rabbits were inoculated with VX2-carcinoma directly into the liver by laparotomy. Computed tomography imaging studies were carried out 9 and 11 days after the inoculation. The investigation was designed as a crossover study. The first group was imaged both as controls (without contrast medium) and with the particulate contrast medium on the 9th day and with iohexol on the 11th day. The second group was imaged with iohexol on the 9th day and as controls, and with the particulate contrast medium on the 11th day. The contrast medium was administered in a dose of 100 mgI/kg. Iohexol was administered in a dose of 570 mgI/kg according to a standard clinical scheme in use at a radiology department for dynamic CT. Changes in normal liver/lesion contrast and the conspicuity of tumors were assessed. On completion of imaging studies on day 11, all animals were killed. The liver was removed and evaluated for the presence of tumors. RESULTS. At macroscopic inspection, all rabbits were found to have tumors ranging from 2 to 14 mm in diameter. The size and location of the tumors corresponded well with the CT images. In the images where the particulate contrast medium was used, the attenuation in the normal liver parenchyma and the contrast between normal liver and lesion was significantly higher compared with the images where iohexol was used or the controls. For all tumor sizes, the lesion detection capability with the particulate contrast medium was significantly higher compared with iohexol (P < .005) and controls (P < .05). CONCLUSIONS. VX2-carcinoma in rabbit liver is a useful model for studying the efficacy of contrast media in CT imaging. The particulate contrast medium IEEC improved visualization of liver tumors

Fracture of the radial head and neck of Mason types II and III during growth: a 14-25 year follow-up

Twenty-four individuals, who were 16 years of age or younger when they sustained a fracture of the radial head or neck, were examined at a mean of 19 years (range 14-25 years) after injury. The 12 girls and 12 boys were a mean age of 11 years (range 5-16 years) when the fracture was sustained. Two were excluded due to late resection of the radial head following persisting pain. The fractures, which were of Mason type II in 19 and type III in three cases, were treated by mobilization in eight cases, plaster in eight, open reduction and internal fixation in three and closed reduction and plaster in three. At the follow-up examination, 19 (86%) had no complaints, while three (14%) had occasional pain. Flexion was decreased in the formerly injured compared with the uninjured elbow (139 + 8degrees versus 142+/-5degrees; P<0.05). None had developed elbow osteoarthritis. Isolated, closed fracture of the radial head and neck during growth has a favourable, long-term outcome

Radiographic findings after cricopharyngeal myotomy

Single film examinations (iodine and/or barium) were reviewed in 28 patients who had undergone surgery on the cricopharyngeal muscle due to Zenker diverticula (24 patients), cricopharyngeal muscle incoordination (3 patients) and pharyngoesophageal web (one patient). All patients had had a myotomy which included the cricopharyngeal muscle and up to 3 cm of the cervical esophagus. Lateral and anterior deviation of the pharynx and cervical esophagus occurred regularly. A pharyngocutaneous fistula developed in 2 patients which healed within 3 weeks. In 5 patients there was a posterior leak of contrast medium during the first postoperative week which healed within 2 weeks. Six of these seven patients with a fistula or a leak had had either a diverticulum removed or sustained an accidental mucosal perforation. No patient had recurrence of diverticula, although, 9 patients developed a cricopharyngeal muscle impression. Iodine and barium examinations are important for monitoring early and late postoperative changes after cricopharyngeus myotomy