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Item type:Publication, Access status: without files , Intelligente Implantate für das Monitoring der Knochenheilung(Springer, 2013-11-30); ; ; ; Background: Monitoring of fracture healing is a complex problem. Radiographs solely enable the estimation of calcification. Telemetric determination of bone healing: A telemetric system to mechanically assess bone healing was developed. The system consists of an electronic unit applied to a locked plate, an external reader and a ground sensor to measure externally applied loads. By correlating the externally applied load and deformation in the implant, the elasticity of the osteosynthesis is calculated. Elasticity decreases with ongoing consolidation of a fracture or nonunion and is appropriate to monitor the course of bone healing. Clinical application: Clinical application was performed in 56 patients suffering nonunions or a fracture of the femur; in 47 cases treatment was completed. In 46 of 47 patients, consolidation was achieved. Different types of healing curves could be differentiated (fast healing, slow healing, plateau with following fast healing, nonhealing). Conclusion: The system proved to be valuable for the judgement of bone healing in difficult healing situations. Routine cost-effective manufacturing is possible, because the used electronic components are derived from mass products.Publicationtype: Journal Article94 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Rückenmarkadaptation : bioresorbierbares Mikrosystem, Medikamentenapplikation, Stammzellen(Springer, 2013-09-05); ; ; ; Background. The idea behind the research project on neuroregeneration after spinal cord injury currently funded by the Deutsche Gesetzliche Unfallversicherung (DGUV) is to combine known drug and cell therapeutic approaches with a surgical procedure. Technique. Damaged spinal cord tissue is resected followed by a tension-free adaptation of the uninjured tissue. For this purpose, a connector element (mMS, mechanical micro-connector system) was developed based on microsystem technologies. The mMS additionally allows the administration of drugs via microchannels Animal trials. In a key experiment in rats, the fixation of the spinal cord tissue, regenerative axon growth through the mMS, and improvement of locomotor function was shown. Currently, further therapeutic combination strategies include the use of substances to reduce fibrotic scar formation, to digest proteoglycans that inhibit axonal growth, stem cells to stimulate axonal growth as well as the chemokine SDF1. Discussion. In order to enable a tension-free adaptation of healthy tissue, depending on the extent of the damage, a shortening of the corresponding spine segment may be necessary. This can be achieved by total vertebral resection. It is known from the literature that total removal of spine segments is technically possible. However, shortening the spine in the course of the treatment of spinal cord damage is new. By combining cellular pharmaceutical treatments with surgical mechanical procedures the neuroregenerative therapy of spinal cord injury seems possible.Publicationtype: Journal Article86 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Telemetric assessment of bone healing with an instrumented internal fixator : a preliminary study(American Orthopaedic Association, 2011-11-01); ; ; ; In an interdisciplinary project involving electronic engineers and clinicians, a telemetric system was developed to measure the bending load in a titanium internal femoral fixator. As this was a new device, the main question posed was: what clinically relevant information could be drawn from its application? As a first clinical investigation, 27 patients (24 men, three women) with a mean age of 38.4 years (19 to 66) with femoral nonunions were treated using the system. The mean duration of the nonunion was 15.4 months (5 to 69). The elasticity of the plate-callus system was measured telemetrically until union. Conventional radiographs and a CT scan at 12 weeks were performed routinely, and healing was staged according to the CT scans. All nonunions healed at a mean of 21.5 weeks (13 to 37). Well before any radiological signs of healing could be detected, a substantial decrease in elasticity was recorded. The relative elasticity decreased to 50% at a mean of 7.8 weeks (3.5 to 13) and to 10% at a mean of 19.3 weeks (4.5 to 37). At 12 weeks the mean relative elasticity was 28.1% (0% to 56%). The relative elasticity was significantly different between the different healing stages as determined by the CT scans. Incorporating load measuring electronics into implants is a promising option for the assessment of bone healing. Future application might lead to a reduction in the need for exposure to ionising radiation to monitor fracture healing. ©2012 British Editorial Society of Bone and Joint Surgery.Publicationtype: Journal Article107 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , "Basketball foot" : long-time prognosis after peritalar dislocation(Thieme, 2008-03); ; ; Subtalar dislocation is considered a severe injury but occurs rarely and studies generally refer to relatively small patient collectives. We investigated the functional outcome in 22 cases to determine the long-term prognosis. Since associated foot injury is common, we compared the outcome for 12 cases of isolated subtalar luxation with 10 cases of collateral fractures of the adjacent bones of the hind foot and Talus. 19 cases of complex, partially open injuries after high energy trauma have got excluded because of the apparently poor long-term results [2, 7, 8]. The Kitaoka-hind-foot-Score (AOFAS) after mean follow up of 8.3 years indicated a significantly better outcome for isolated luxation. Nearly 50% of isolated luxations had a excellent outcome (73%, mean score 89), luxations with associated fractures had mainly good and fair results (73%, mean score 74). Analysis of the gait pattern by dynamic plantar pressure measurement demonstrated lower pressures in the isolated luxation group and higher pressures in the group with associated fractures in the lateral region of the forefoot with shorter phases of weight bearing. © Georg Thieme Verlag KG Stuttgart.Publicationtype: Journal Article10