Biomedical subjects

Chr van der Werken

Publications and source records attributed to Chr van der Werken.

11 recordsLinked to original sources

PubMed2006

[Background and consequences of injuries missed when diagnosing severely injured accident victims in prehospital care in patients transported by ambulance to the University Medical Centre in Utrecht, 1999-2000].

OBJECTIVE: To determine the background and consequences of failing to diagnose injuries in prehospital care. DESIGN: Prospective cohort study. METHOD: Data were collected from 507 trauma patients with multiple injuries, and a Hospital trauma index-injury severity score of 16 or higher, who were delivered by the emergency ambulance service to the emergency department of the University Medical Centre Utrecht, the Netherlands, in 1999-2000. RESULTS: The percentage of missed injuries varied from 9-55. For every additional year of age the risk of missing thoracic injuries was 2% higher. The risk of missing head injuries was 84% lower in people with a Triage revised trauma score (T-RTS) < 11. Initially missing an injury had no consequences for duration of stay in the ICU except in those patients with injuries to the lower extremities. A difference in quality of life was only reported for patients in whom injuries ofthe ribs, shoulder or clavicle had been missed. For every year of age, there was a 2% greater risk of dying within 1.5 years. A T-RTS < 11 resulted in a 5.6-fold greater risk of death. Failing to diagnose an injury did not in itself increase the risk of death. CONCLUSION: Frequently missing an injury prior to hospitalization did not result in a poorer chance of survival or lesser quality of life. The risk of dying was mainly related to a higher age and a poorer general condition at the scene of the accident. According to these findings there is no reason to adapt the current policy with regard to initial care and transport of trauma patients.

Ambulances↗

PubMed2006

Interface pressure measurement during surgery: a comparison of four operating table surfaces.

OBJECTIVE: To compare the pressure-reducing and pressure-redistributing characteristics of four operating room (OR) table mattresses using interface pressure measurements, in two positions adopted for surgical procedures. METHOD: Support surfaces were randomly assigned to 80 patients. These were: an overlay pad filled with fibres (the standard OR mattress), a custom-made viscoelastic polyurethane foam mattress, an inflatable mattress with air-filled cells and a fluid mattress. An XSENSOR full-body pressure-mapping pad was used to record interface pressures of 40 patients in the supine position and 40 patients in the lithotomy position. Measurements were analysed for peak pressure, peak pressure index, total contact surface area and the occurrence of a significant increase in interface pressure during the surgical procedure. RESULTS: The highest interface pressures were measured on the standard mattress, in both the supine and lithotomy position. Overall, the fluid mattress showed the best pressure-reducing and pressure-redistributing capacities. CONCLUSION: As long as no reference values are available for interface pressures under which no pressure-related damage will occur, clinical testing of OR table surfaces is still necessary.

Beds↗

PubMed2005

Soft tissue injury related to choice of entry point in antegrade femoral nailing: piriform fossa or greater trochanter tip.

Intramedullary nailing through the piriform fossa results in some cases in loss of abduction strength and persistent pain. Nail insertion at the tip of the greater trochanter may be favourable. The aim of this study was to assess (possible) iatrogenic injury to the abductor and external rotator musculature, branches of the superior gluteal nerve and branches of the MFCA in relation to the two different entry points. In 10 fresh human cadaver femurs, five unreamed femoral nails (UFN) were inserted through the piriform fossa and five AO prototype nails (AFN) through the trochanteric tip. The iatrogenic injury at each nailing procedure was assessed. Various muscles and tendons, branches of the MFCA along with the hip joint capsule were injured or largely at risk during nail insertion through the piriform fossa. Most of these structures were not exposed during insertion through the trochanteric tip. The reported clinical morbidity after nailing through the piriform fossa may find its origin in direct soft tissue injury and may be reduced by choosing a lateral nail entry point.

Aged↗

PubMed2005

The floating shoulder.

Ipsilateral scapular neck and clavicular shaft fractures comprise the so-called "floating shoulder". This rare injury, which is, in general, caused by a high-energy trauma, is perceived to be an unstable injury with the considerable risk of significant displacement of scapular neck and/or the clavicular fracture. An understanding of the patho-anatomy is important in identifying a floating shoulder and to offer rational treatment for this injury. The current status of the anatomical, biomechanical and clinical aspects of a floating shoulder is reviewed in this article. Recommendations for treatment of particularly displaced ipsilateral fractures of the scapular neck and clavicular shaft cannot be derived from the reported clinical studies. The possible correlation between functional outcome and malunion of the scapular neck is called into doubt.

Clavicle↗

PubMed2004

[Missed acute compartment syndrome of the lower leg].

After some considerable delay, acute compartment syndrome of the lower leg was diagnosed in a 17-year-old man, a 32-year-old man and a 76-year-old woman. The first patient was an accident victim whose leg was continuously bandaged for three days following treatment of a complicated femur fracture and lower leg wounds, so that inspection was not possible. In the second patient who was also an accident victim, the haemodynamics and the neurological condition initially required so much attention that the compartment syndrome was only noticed after 48 hours. The woman presented with a cold, painful left foot. She had atrial fibrillations. A thrombus mass was removed endovascularly from the femoral artery. She controlled her own pain medication by means of an epidural catheter, but as a result of that a reperfusion compartment syndrome was only noticed at a later stage. These cases reveal that it can be very difficult to establish the diagnosis of acute compartment syndrome, especially if this is masked by the already quite subjective symptoms of the clinical picture. The consequences of a missed compartment syndrome are serious, with a considerable impairment of the limb concerned that often necessitates amputation. Awareness and healthy suspicion are the keys to a quick and timely diagnosis. Prophylactic fasciotomies must be carried out on the basis of several clear indications.

Adolescent↗

PubMed2004

The evolution of Pseudomonas aeruginosa during antibiotic rotation in a medical intensive care unit: the RADAR-trial.

Bacterial spread between patients may contribute to the high prevalence of antibiotic-resistant pathogens within ICUs. The aim of this study was to evaluate the fate of Pseudomonas aeruginosa during the different antibiotic regimens. Susceptibility patterns and genotyping were performed to determine whether there was a predominant clone and to track the spread of resistant strains within the unit. Twenty-eight different ribotypes were found among 82 Pseudomonas isolates. Four ribotypes accounted for 42 (51%) isolates and were designated the "major clones" occurring throughout multiple cycles. The ribotypes with multiple occurrences were more resistant to antibiotics than ribotypes that appeared only once. The correlation of antibiotic use with antibiotic resistance and the finding of a large number of ribotypes suggested that de novo development of antibiotic resistance is a likely event in P. aeruginosa. In addition, ribotypes associated with antibiotic resistance appeared to have a survival advantage and can become frequent colonizers in the ICU.

Anti-Bacterial Agents↗

PubMed2004

Unstable trochanteric femoral fractures: extramedullary or intramedullary fixation. Review of literature.

For operative treatment of unstable trochanteric fractures two options exist: extramedullary or intramedullary stabilisation. A review of 18 international papers that compared two different treatment methods for trochanteric fractures, in prospective randomised clinical trials, is presented. In view of the overall results, routine use of intramedullary fixation devices is not to be recommended for stable trochanteric fractures. For these fractures one of the sliding hip screw systems provides a safe and simple alternative. For unstable fractures intramedullary implants are (biomechanically) superior. The review shows that clinical advantages of both treatment methods are suggested and advocated, but still remain to be demonstrated on evidence base.

Analysis of Variance↗

PubMed2003

Anatomical considerations for surgery of the anterolateral abdominal wall.

Closure of large incisional hernias with the Components Separation Method (CSM) could be explained by medial-caudal rotation of the internal and transverse oblique muscles around their centres of origin. In eight human cadavers, the CSM was performed, and translation of the rectus abdominis muscle was measured. Mean unilateral translation of the rectus abdominis in the lateral-medial direction measured 2.2, 3.7, and 3.5 cm. This was 2.7, 4.5, and 4.0 cm after release of the posterior rectus sheath. Mean translation in a caudal direction was 0.5 cm, but seven cadavers showed a mean translation of 1 cm of the uppermost measuring point in a cranial direction. The hypothesis that rotation of separate tissue layers of the abdominal wall largely accounts for the translation effect of the CSM must be rejected. Release of the external oblique muscle produces more benefit to abdominal wall closure than release of the posterior rectus sheath.

Abdominal Muscles↗

PubMed2003

Computer assisted orthopaedic and trauma surgery. State of the art and future perspectives.

In recent years computer technologies have become more and more integrated in surgical procedures. The potential advantages of computer assisted surgery (CAS) are: increase of accuracy of surgical interventions, less invasive operations, better planning and simulation and reduction of radiation exposure for both patient and surgeon. After introduction of CAS in neurosurgery, the clinical applications of this technique expanded also into trauma and orthopaedic surgery. The first application of this new technique in orthopaedic and trauma surgery was for placement of lumbar pedicle screws. After its introduction into spine surgery, CAS was applied in other fields of orthopaedic surgery like hip, knee and skeletal trauma surgery. In this article the technical background and the various clinical applications and future perspectives of computer assisted orthopaedic and trauma surgery are outlined.

Forecasting↗

PubMed2002

[The adverse effects of smoking on healing of open tibial fractures].

OBJECTIVE: Survey of the influence of smoking on the healing of open tibial fractures. DESIGN: Retrospective. METHOD: During the period 1 January 1994 to 31 December 2000, 168 patients were treated at the Department of Surgery (University Medical Center Utrecht, the Netherlands) due to an open tibial fracture; 118 patients with 125 fractures were included in the study. On the basis of their smoking behaviour, patients were classified as 'non-smokers' or 'smokers'. For all of the patients it was ascertained whether or not complications had occurred during treatment. Whether the fracture had consolidated was determined on the basis of clinical and radiological criteria. RESULTS: Seventy-two (61%) patients were non-smokers and 46 were smokers. The non-smokers had 77 open tibial fractures and the smokers 48. Initial therapy was identical and wound infections occurred with similar incidences in both groups. However, there was a statistically significant difference in the incidence of osteitis between both groups: 7 (9%) times in the non-smokers and 13 (27%) times in smokers (p = 0.04). The mean time to consolidation was 26 weeks for non-smokers and 33 weeks for smokers (p = 0.04). Smokers remained longer in hospital and underwent more re-operations. CONCLUSIONS: Smoking was negatively associated with the healing of open tibial fractures. In smoking patients, the time to consolidation was on average statistically significantly longer and they suffered more from osteitis.

Adult↗

PubMed2002

Validation of fluoroscopy-based navigation in the hip region: what you see is what you get?

Fluoroscopy-based navigation systems can be used for internal fixation of intracapsular femoral neck fractures, with the object of optimizing positioning of the implant and reducing radiation exposure. With this technique, the virtual position and direction of a reamer can be simultaneously superimposed on anteroposterior (AP) and axial (AX) fluoroscopic images. However, surgeons have to rely on the accuracy of these systems, because the only intraoperative feedback on the true position of the reamer is the projection of a virtual reamer superimposed on two fluoroscopic images. The objective of this study was to evaluate the accuracy of the displayed position of the virtual reamer in relation to the true position of the instrument when using a fluoroscopy-based navigation system (medivision, Oberdorf, Switzerland). Secondary to this, the accuracy of the drill-channel measuring tool of the system was analyzed. The study was performed on 20 sawbones. To evaluate the position of the virtual reamer, an 8-mm Perspex bar was inserted in predefined drill channels in each sawbone. AP and AX fluoroscopic images of the sawbones with the Perspex bar were loaded into the workstation. The Perspex bar was then removed and exchanged for a navigated dynamic hip screw (DHS) reamer. The position of the Perspex bar in the images represented the true position of the reamer. Subsequently, the difference between the position of the virtual reamer and the Perspex bar was measured with a dedicated computer program. Drill-channel lengths measured with the system were compared with measurements obtained with a digital ruler. The mean difference in position of the Perspex bar and reamer at a predefined point was 0.90 mm (range: 0.00-3.21 mm) in 360 images. The mean difference in length measurements between the medivision system and the digital ruler was 1.00 mm (p = 0.01, SD =1.33). Reaming and measuring the screw channel of a DHS with a medivision fluoroscopy-based navigation system can be performed with an acceptable error margin.

Femoral Neck Fractures↗