Technology and Health Care - Volume 22, issue 6

Authors: Bredow, Jan | Wenk, Birte | Westphal, Ralf | Wahl, Friedrich | Budde, Stefan | Eysel, Peer | Oppermann, Johannes

Article Type: Research Article

Abstract: Background: Revision joint replacements are challenging surgical tasks. Knowing the exact type of primary prosthesis is essential to avoid long preoperative organisation, long operation times, and especially loss of bone and soft-tissue during operation. In daily routine there is often no information about the primary prosthesis. Objective: We are developing methods for identifying implanted prostheses from x-ray images by means of matching template images generated from prosthesis CAD data. Methods: The application is separated into three major components: The “Template Image Generation” adds 3d models of endoprostheses to a database. The “X-ray Image Segmentation” extracts endoprostheses …from provided sets of x-ray images. The “Template Matching” finds the best matching prosthesis types in the data base. At the current stage, one prosthesis model (Corin, Knee ProthesisUniglide) was used for evaluating these algorithms. Results: Very accurate identifications with accuracies of about 90% for lateral and over 70% for frontal images could be achieved. Conclusions: The current results of this feasibility study are very promising. A reliable and fast prosthesis identification process seems realistic to support the surgeon when planning and performing revision arthroplasty. Further improvements of segmentation accuracies and extending the prosthesis data base are intended next steps towards this goal. Show more

Keywords: Revision arthroplasty, x-ray, image segmentation, template matching, prosthesis

DOI: 10.3233/THC-140858

Citation: Technology and Health Care, vol. 22, no. 6, pp. 895-900, 2014

Authors: Mommsen, Philipp | Doering, Matthias | Röhrs, Ehrenfried | Egidy, Claus | Gehrke, Thorsten | Krettek, Christian | Kendoff, Daniel

Article Type: Research Article

Abstract: Background: Low-molecular-weight heparins (LMWH), e.g. enoxaparin, represent the standard thromboprophylactic agents in Europe after total hip replacement. The oral direct thrombin inhibitor dabigatran etexilate provides comparable effectiveness and safety. The present study aimed to evaluate the influence of dabigatran etexilate on perioperative blood loss and wound secretion in total hip arthroplasty compared to enoxaparin. Methods: Patients receiving primary total hip replacement between January and June 2009 were included. The association between thromboembolism prophylaxis with dabigatran etexilate or enoxaparin and the perioperative blood loss was investigated. The effective blood loss (EBL) was calculated taking blood transfusions and the difference …between preoperative haemoglobin and haemoglobin on the day of discharge into account. Additional comparison of wound secretion depending on thromboprophylactic agents was performed in a separate, prospectively collected patients' population. Statistical analysis was performed with χ2 -Test, Student's t-test or Mann-Whitney U-test. Statistical significance was considered at p < 0.05. Results: 198 patients (111 women, 87 men) with primary total hip arthroplasty were enrolled. Patients' mean age was 63.0 ± 11.9 years. Thromboembolism prophylaxis was performed in 111 patients (56.1%) with dabigatran etexilate, 87 patients (43.9%) received enoxaparin. No significant differences concerning EBL and wound secretion were found between both study groups. In the dabigatran etexilate group the EBL was 1.66 ± 0.56 l compared to 1.77 ± 0.65 l in patients with enoxaparin. Conclusions: Dabigatran etexilate can safely be used for thromboembolism prophylaxis after primary total hip replacement without an increased risk for perioperative blood loss and prolonged wound secretion. Show more

Keywords: Hip arthroplasty, thromboembolism prophylaxis, blood loss, wound secretion, dabigatran etexilate, enoxaparin

DOI: 10.3233/THC-140859

Citation: Technology and Health Care, vol. 22, no. 6, pp. 901-908, 2014

Authors: Reising, K. | Konstantinidis, L. | Helwig, P. | Wagner, F.C.L. | Südkamp, N.P. | Strohm, P.C.

Article Type: Research Article

Abstract: Background: Fracture of the distal humerus is a fairly rare injury and makes high demands on the treating surgeon. Prerequisites for a good outcome are anatomical reconstruction and osteosynthesis stable enough for exercises. A method permitting early restoration of function is especially important for patients with osteoporosis. The extensive surgical approach necessary for open reduction is associated with a high number of wound healing disorders and infections with a frequency of 11% being reported in the literature. Although open reduction and internal fixation in double-plating technique is unavoidable for complex intraarticular fractures, an alternative, minimally invasive and, consequently, tissue-preserving procedure …is desirable for simpler fractures. Objectve: To investigate this issue further an angular stable nail system developed for the distal radius was implanted as a stabilizer and the construct tested biomechanically as part of a feasibility study. Methods: Distal humerus fractures were stabilized by insertion of a distal radius nail, namely, the Targon DR (Aesculap, Tuttlingen) and a K-wire. To test the hypothesis six cadaveric bones fixed in formalin were tested biomechanically for displacement, implant failure, and stiffness. Displacement was determined by means of an ultrasound-based system. Results: An average displacement of 1.6 mm ± 0.7 was recorded at a maximum compression force of 100 N in extension and an average displacement of 1.4 mm ± 0.9 in flexion. Implant failure was not observed for any of the constructs. Conclusions: The study presented here permits the conclusion that a minimally invasive procedure is possible at the distal humerus and does ensure adequate stability. Although the nail was not specifically designed for the humerus, current findings form the basis for a promising approach that will be pursued further after modification of the nail design. Show more

Keywords: Distal humerus fracture, minimal invasive, nail osteosynthesis, angular stable

DOI: 10.3233/THC-140864

Citation: Technology and Health Care, vol. 22, no. 6, pp. 909-913, 2014

Authors: Yeh, Shih-Ching | Chen, Shuya | Wang, Pa-Chun | Su, Mu-Chun | Chang, Chia-Huang | Tsai, Po-Yi

Article Type: Research Article

Abstract: Background: Chronic imbalance is common in patients with vestibular dysfunction. Vestibular rehabilitation is effective in improving upright balance control. Vestibular rehabilitation exercises, such as Cawthorne-Cooksey exercises, include simple repetitive movements and have limited feedback and adaptive training protocols. Interactive systems based on virtual reality (VR) technology may improve vestibular rehabilitation. Objective: The objective of this study was to examine the effectiveness of an interactive 3-dimensional VR system for vestibular rehabilitation. Methods: In 49 subjects with vestibular dysfunction, VR rehabilitation exercises were performed in 6 sessions. Before and after rehabilitation, subjects were evaluated for performance of the …training exercises; the center of pressure was measured for 20 seconds and balance indices were determined. Results: Five training scores (total 6) showed a significant improvement. For balance indices in condition of non-stimulation, all of them (total 5) showed a trend of improvement, in which there was a significant improvement in mean mediolateral. For balance indices in condition of post-stimulation, there was a significant improvement in statokinesigram and maximum mediolateral. Conclusions: The VR rehabilitation exercises were effective in improving upright balance control in patients with vestibular dysfunction. Show more

Keywords: Balance, rehabilitation, virtual reality, vestibular

DOI: 10.3233/THC-140855

Citation: Technology and Health Care, vol. 22, no. 6, pp. 915-921, 2014

Article Type: Other

DOI: 10.3233/THC-2014-22615

Citation: Technology and Health Care, vol. 22, no. 6, pp. 923-934, 2014

Article Type: Other

DOI: 10.3233/THC-2014-22616

Citation: Technology and Health Care, vol. 22, no. 6, pp. 935-939, 2014