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159 results on '"Werken, Chr."'

16. Validation of Fluoroscopy-Based Navigation in the Hip Region: What you See is What you Get?

Author

Schep, N. W. L., van Walsum, Th, de Graaf, J. S., Broeders, I. A. M. J., van der Werken, Chr, and Other departments

Subjects
Surgery, Family Practice, Computer Science Applications
Abstract

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

Published
2002

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

Author

Schipper, I. B., Marti, R. K., van der Werken, Chr, and Orthopedic Surgery and Sports Medicine

Subjects
musculoskeletal system
Abstract

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

Published
2004

25. Acute Achilles tendon rupture Treatment strategies and outcomes

Author

JC onderzoeksprogramma Methodologie, Zorgeenheid Traumatologie, van der Werken, Chr., van der Heijden, Geert, Verleisdonk, Egbert Jan M M, Metz, R., JC onderzoeksprogramma Methodologie, Zorgeenheid Traumatologie, van der Werken, Chr., van der Heijden, Geert, Verleisdonk, Egbert Jan M M, and Metz, R.

Published
2009

35. Ascites after pleuroperitoneal shunting

Author

Roukema, J.A., Lobach, H.J.C., and van der Werken, Chr.

Subjects
Peritoneovenous shunts -- Usage, Pleural effusions -- Complications, Ascites -- Causes of, Ascites -- Case studies, Health
Abstract

Some terminal cancer patients develop effusions of fluid in the pleural cavities which enclose the lungs. These effusions have a serious effect upon the well-being of the patient. Consequently, the patient's quality of life may be substantially improved by draining this fluid. Often tube drainage or the aspiration of fluid with a syringe is adequate. However, in some cases a shunt may be inserted to facilitate drainage into the peritoneal cavity, between the linings of the abdominal organs and the abdominal cavity. However, in a recent case, physicians observed a patient in whom the implantation of such a shunt resulted in the accumulation of ascites fluid in the patient's abdominal cavity. Sometimes such fluid accumulation results from the presence of cancer cells in the peritoneal cavity, but malignant cells could not be observed in this case. On the presumption that ascites was a result of shunting the pleural fluid, a new shunt was implanted to return the pleural fluid to the venous circulation. Ascites did not recur after the shunt was changed. The patient died six months later of multiple lung metastases. (Consumer Summary produced by Reliance Medical Information, Inc.)

Published
1990

47. Open Management of the Abdomen and Planned Reoperations in Severe Bacterial Peritonitis.

Author

Bosscha, K., Hulstaert, P. F., Visser, M. R., van Vroonhoven, Th. J. M. V., and van der Werken, Chr.

Subjects
OPERATIVE surgery, PERITONITIS, ABDOMINAL surgery, THERAPEUTICS
Abstract

Objective: To assess the results of open management of the abdomen and planned re-operations in severe bacterial peritonitis after perforation or anastomotic disruption of the digestive tract. Design: Retrospective study. Setting: University Hospital, The Netherlands. Subjects: 67 consecutive patients. Interventions: Open management of the abdomen and planned reoperations. Main outcome measures: Hospital morbidity and mortality, long-term follow-up. Results: 38 patients developed multiple organ failure (MOF), but 29 needed only ventilatory and inotropic support. The mean number of re-operations was nine. 16 patients developed severe bleeding and 16 fistulas. In-hospital mortality was 42% (n = 28). Long-term morbidity, particularly the number of abdominal wall defects (n = 10), was considerable. Conclusion: Despite open management of the abdomen and planned re-operations, mortality of severe bacterial peritonitis still continues to be too high, and both short and long-term morbidity are appreciable. The value of open management of the abdomen and planned re-operations rests only on the clinical observation that other conventional surgical treatments of severe bacterial peritonitis often fail. [ABSTRACT FROM AUTHOR]

Published
2000
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