Biomedical subjects

Arne Wagner

Publications and source records attributed to Arne Wagner.

20 records · Page 2Linked to original sources

PubMedDate not supplied

Interactive stereotaxic teleassistance of remote experts during arthroscopic procedures.

This article describes the technical setup for stereotaxic telesurgical assistance for arthroscopic procedures. It also outlines the current state, limitations, and feasibility of this technical development. Teleassistance or teleconsultation implemented in endoscopic or arthroscopic procedures have not yet been reported. In this study, 7 computer-assisted arthroscopies of the temporomandibular joint were supported by extramural experts via interactive stereotaxic teleconsultation from distant locations. The external experts were supplied with close to real-time video, audio, and stereotaxic navigation data directly from the operation site. This setup allows the surgeons and external experts to interactively determine portals, target structures, and instrument positions relative to the patient's anatomy and to discuss any step of the procedures. Optoelectronic tracking interfaced to computer- based navigation technology allowed precise positioning of instruments for single or multiple temporomandibular joint punctures. The average error of digitizing probe measurements was 1.3 mm (range, 0.0 to 2.5 mm) and the average standard deviation was 0.7 mm (range, 0.4 to 0.9 mm). Evaluation of the reliability and accuracy of this technique suggests that it is sufficient for controlled navigation, even inside the small temporomandibular joint, a fact that encourages further applications for arthroscopy in general. The minimum requirement for high-quality video transmission for teleassisted procedures are integrated services digital network (ISDN) connections. Conventional ISDN-based videoconferencing can be combined with computer-aided intraoperative navigation. Transmission control protocol/internet protocol (TCP/IP)-based stereotaxic teleassistance data transmission via ATM or satellite seem to be promising techniques to considerably improve the field of arthroscopy.

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PubMedDate not supplied

Measurement of volume changes after sinus floor augmentation with a phycogenic hydroxyapatite.

PURPOSE: The purpose of this study was the determination of time-dependent volumetric changes of particulate sinus inlay grafts. A mixture of phycogenic hydroxyapatite (Algipore/C-Graft) and autologous bone collected from the surgical access area was used as the grafting material. MATERIALS AND METHODS: Thirty-three sinus floor augmentations using phycogenic hydroxyapatite combined with autologous bone collected at the augmentation site and venous blood were performed on 18 patients aged 57.4 +/- 12.5 years (mean +/- SD) with severe atrophy of the posterior maxilla. Graft volume was measured 1 to 14 days postoperatively and before the placement of dental implants 6.1 +/- 2.1 months later (mean +/- SD; range, 4 to 11 months) to evaluate the amount of time-dependent resorption of the implanted material on computerized tomographic (CT) images of the augmented region. The images were put into Digital Imaging and Communications in Medicine (DICOM) format and evaluated using the software library Analyze. The implanted bone replacement material was plotted manually on each CT slice, and the volume of the implanted material was calculated. RESULTS: The average volume loss of the bone replacement material during the observation period was 13.9% +/- 1.9% (mean +/- SEM). All sinus floor augmentations healed without complications except for delayed membrane exposure in 2 cases. DISCUSSION: The results indicate that the graft material, a mixture of Algipore, bone chips from the access area, and venous blood, exhibited a small volume loss over a period of approximately 6 months, thus providing predictable height for second-stage implant surgery. CONCLUSION: Further investigations are needed to evaluate long-term stability and implant success.

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