Rapid prototype patient-specific drill template for cervical pedicle screw placement.

OBJECTIVE: To assess the feasibility and accuracy of a drill template for the placement of a cervical pedicle screw in a single vertebral level. MATERIALS AND METHODS: A volumetric CT scan was performed on a cadaver cervical spine. Using computer software, a drill template with a predefined trajectory was constructed that was designed to match the posterior surface of the right side of the fifth cervical vertebra. A physical template was created from the computer model using a rapid prototyping machine. The drill template was used to guide drilling of a pilot hole, and a CT scan was performed to assess the accuracy of this hole. A 3.5-mm diameter pedicle screw was placed in the pilot hole. The spine was then dissected to separate the vertebrae and the trajectory of the screw was visually inspected. RESULTS: The feasibility of this patient-specific rapid prototyping technique was demonstrated. Imaging and visual inspection confirmed accurate placement of the pilot hole and cervical pedicle screw without cortical violation. CONCLUSIONS: The potential use of drill templates to place cervical pedicle screws is promising. Our initial methodology appears to provide an accurate technique and trajectory for pedicle screw placement in the cervical spine.     

Altered central micro-opioid receptor binding after psychological trauma.

BACKGROUND: Functional neuroimaging studies have detected abnormal limbic and paralimbic activation to emotional probes in posttraumatic stress disorder (PTSD), but few studies have examined neurochemical mechanisms that underlie functional alterations in regional cerebral blood flow. The mu-opioid neurotransmitter system, implicated in responses to stress and suppression of pain, is distributed in and is thought to regulate the function of brain regions that are implicated in affective processing. METHODS: Here we examined the micro-opioid system with positron emission tomography and the micro-opioid receptor-selective radiotracer [11C] carfentanil in 16 male patients with PTSD and two non-PTSD male control groups, with (n = 14) and without combat exposure (n = 15). Differences in micro-opioid receptor binding potential (BP2) were detected within discrete limbic and paralimbic regions. RESULTS: Relative to healthy controls, both trauma-exposed groups had lower micro-opioid receptor BP2 in extended amygdala, nucleus accumbens, and dorsal frontal and insular cortex but had higher BP2 in the orbitofrontal cortex. PTSD patients exhibited reduced BP2 in anterior cingulate cortex compared with both control groups. Micro-opioid receptor BP2 in combat-exposed subjects without PTSD was lower in the amygdala but higher in the orbitofrontal cortex compared with both PTSD patients and healthy controls. CONCLUSIONS: These findings differentiate the general response of the micro-opioid system to trauma from more specific changes associated with PTSD.     

Wirbelsäulenverletzungen des thorakolumbalen Übergangs

Trauma und Berufskrankheit - Eine einheitliche Behandlungsstrategie thorakolumbaler Wirbelfrakturen hat sich lange Zeit nicht etablieren können. Heute ist bei stabilen Frakturen mit intakter...     

Cervical soft tissue imaging using a mobile CBCT scanner with a flat panel detector in comparison with corresponding CT and MRI data sets.

OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.     

Distale Humerusfrakturen

Distal humeral fractures are problematic both in children and in adults. While in children these fractures are very common and most of them have an extraarticular location, in adults their incidence is much lower and they more often compromise the joint. Good results cannot be achieved without due consideration for the complex anatomy of the elbow joint, the quality of the bone, the concomitant soft tissue lesions and the biomechanical aspects of the injury, to allow selection of appropriate therapy and a correctly structured aftertreatment. The soft tissue injuries that are frequently involved and the high rate of intra- and postoperative complications need particular attention. This paper reviews the epidemiology, the current standards in diagnosis and therapy, the possible complications and the results that can be expected in patients with fractures of this type.     

Follow up of patients with colorectal polyps: are the BSG guidelines being adhered to?

OBJECTIVE: The publication of the BSG guidelines in 2002 provided a framework for the follow up of patients with colorectal polyps. The aim of the present study was to determine whether they had, or were being correctly adhered to in a moderately sized District General Hospital. METHOD: A total of 598 patients were on the waiting list for colonoscopy at Airedale General Hospital (AGH) in February 2005. Of these, 203 were being followed up as a result of the previous finding of a polyp. RESULTS: Only 14.8% of patients had been or were being followed up according to the BSG guidelines. The majority of the 85.2% of patients who did not comply with follow up did so as a result of over investigation. Seventy-eight per cent of the low-risk group and 55% of the intermediate-risk group had been colonoscoped, or were waiting to have colonoscopy, too soon or too frequently according to the BSG guidelines. Twenty-four patients with hyperplastic polyps were being followed up incorrectly, as were 17 patients discovered to have a polyp pathology on flexible sigmoidoscopy. It was established that 131 extra colonoscopies had been, or were planned to be performed unnecessarily. CONCLUSION: These data have major implications with regard to patient safety, service provision and cost to the NHS.     

Individualized Mycophenolate Mofetil Dosing Based on Drug Exposure Significantly Improves Patient Outcomes After Renal Transplantation

Efficacy and safety of mycophenolate mofetil (MMF) may be optimized with individualized doses based on therapeutic monitoring of its active metabolite, mycophenolic acid (MPA). In this 12-month study, 137 renal allograft recipients from 11 French centers receiving basiliximab, cyclosporine A, MMF and corticosteroids were randomized to receive either concentration-controlled doses or fixed-dose MMF. A novel Bayesian estimator of MPA AUC based on three-point sampling was used to individualize doses on posttransplant days 7 and 14 and months 1, 3 and 6. The primary endpoint was treatment failure (death, graft loss, acute rejection and MMF discontinuation). Data from 65 patients/group were analyzed. At month 12, the concentration-controlled group had fewer treatment failures (p = 0.03) and acute rejection episodes (p = 0.01) with no differences in adverse event frequency. The MMF dose was higher in the concentration-controlled group at day 14 (p < 0.0001), month 1 (p < 0.0001) and month 3 (p < 0.01), as were median AUCs on day 14 (33.7 vs. 27.1 mg*h/L; p = 0.0001) and at month 1 (45.0 vs. 30.9 mg*h/L; p < 0.0001). Therapeutic MPA monitoring using a limited sampling strategy can reduce the risk of treatment failure and acute rejection in renal allograft recipients 12 months posttransplant with no increase in adverse events.     

Abdominal aortic aneurysm repair and colonic infarction: a risk factor appraisal

OBJECTIVE: Colonic infarction is a recognized complication of abdominal aortic aneurysm (AAA) surgery. The clinical difficulty in establishing the diagnosis combined with the patient's poor physiological status is usually associated with a fatal outcome. We assessed our experience with this problem to identify a possible risk factor profile for these patients. METHOD: Patients records were identified from the operative logs, intensive care unit, Hospital Inpatient Enquiry system and vascular unit databases over a 6-year period. RESULTS: A total of 405 patients underwent AAA repair during this period; 140 as emergency ruptures. Nine patients were identified from the databases with known colonic infarction (2.2%). One was a woman. The mean age was 70 years. Seven patients had emergency ruptures (5%). Twenty independent risk factors were analysed using univariate and multivariate logistic regression models. Significant risk factors identified by using a multivariate analysis included the nature of the presenting patient, preoperative hypotension, prolonged cross-clamp time, intra-operative ischaemia and postoperative acidosis. Confirmatory diagnosis was made by colonoscopy in eight patients. One patient survived following the salvage surgery. The mean duration of survival was 10.5 days. The overall mortality was 89% of patients. CONCLUSION: In our unit infrarenal AAA repair has a 2.2% rate of colonic infarction. A definitive diagnosis is best made by colonoscopy. A risk factor profile for the development of colonic infarction may be constructed on the basis of specific clinical parameters. Earlier intervention on the basis of this profile may ultimately reduce the current excessive mortality.