Hungarian Society of Biomechanics: E-Journals / Magyar Biomechanikai Társaság
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Novel minimal invasive surgical techniques for the treatment of segmental-lateral pathologic lesions of the spine, preserving the dorsal stabilizing structures
Get PDFObjective: Laminectomy, the commonly used dorsal approach for the surgical removal of most of the pathologic lesions, situated in the spinal canal and the neuroforamen destroying the dorsal stabilizing structures of the spinal column. Retraction and detachment of the longitudinal muscles, removal of the vertebral arches (laminectomy), and injury of the joint capsules and ligaments are responsible most of short and late-time complications. Among of these complications spinal deformities, segmental instability and permanent spinal pain are most often mentioned in the literature. The main objective of the authors was to develop and evaluate the novel minimally invasive techniques suitable for exploring and treating different segmental-lateral pathologies, expanding to the neuroforamen or even paravertebraly, with preservation of the stability of the spine. One of the key issues of this article was to summarize these procedures, with evaluating the safety and efficacy in the routine spine surgery. Methods: 153 patients were operated and followed up during 2000 to 2010 in our Institute with segmental lateral spinal pathologies. For the surgical treatment we used “Over-the-top” decompression, hemi-semi laminectomy, supraforaminal burr-hole, open-tunnel and paravertebral approaches alone or combined with each-other. The above mentioned surgical techniques are mostly our developments, or modifications of previously used surgical techniques.Results: The new surgical procedures developed or modified by our team, are effective techniques for treating the spinal pathologies located in the spinal canal, neuroforamen or even the paravertebral space. The posterior stabilizing structures of the spine, as the vertebral laminae and the longitudinal musculature are mostly preserved. Leaving the longitudinal paraspinal musculature innervations intact, and with the preservation of the bone-muscle attachments and ligaments, the dynamic stability of the spine remains unchanged. Retaining the bony structures (vertebral arches) and the vertebral joints the static stability of the spinal column remain intact, the chance of developing the long-term spinal deformation is minimal.During the follow up we performed static and dynamic X-ray, MR and CT scans, completed with neurological examinations to evaluate the progression of the illness, the neurological deficit and the actual state of the spinal column. With clinical use and evaluation of the various surgical approaches we determined the main indications and contraindications of the surgical procedures, highlighting the pit-falls and limitations.Conclusion: The above mentioned minimally invasive surgical approaches are suitable for treating segmental – lateral spinal pathologies. . For the routine clinical use we organized the surgical techniques into a complete framework based on the location of the pathologic lesions. DOI: 10.17489/biohun/2013/1/2
Effect of kayaking on balancing ability after sudden changes in direction
Get PDFIntroductionDifferent sports influence the balancing ability variously. The aim of this study to examine the effect of kayaking on dynamical balancing ability after sudden changes in direction.MethodsThe investigation included 5 race-kayakists and 5 leisure-time sportsmen. Dynamical balancing ability have analyzed by the ultrasound-based sudden perturbation test (provocation test). A rigid platform have moved from its central position and fixed by a fastening unit. The rigid platform connected to a rigid frame by 4 or 8 steel springs of identical strength. The platform swings back into its original, resting position, stimulating sudden disturbances after releasing the fastening unit. The participant must balance and re-equilibrate as the plate moves. The motions of the rigid plate were recorded by an ultrasound-based system. From this motion the Lehr’s damping ratio can be calculated and it characterizes the balancing ability of the investigated person.ResultsFor the kayakist group, the average values of the Lehr’s damping ratio determined were significantly bigger while standing on one limb and on both limbs compared to the parameters for the control group.DiscussionA high level of complex coordination is required to regain equilibrium after a sudden change in direction. Sports activities can develop this ability. This investigation demonstrate that not only the traditional methods (a sudden stoppage from running, sudden setting in motion, jumping or changing in direction) but motion in a continuously moving media (in aqueous media) can also develop the balancing ability. During kayaking the media always changes; moreover, it often surges so persistent balancing is essential. The results draw attention to the fact that dynamic balancing ability can be developed by other than traditional methods. DOI: 10.17489/biohun/2013/1/3
Garments under brace life quality improve affect experiment of technology and physiology
Get PDFScoliosis is a spinal deformity that most commonly appears in girls and makes itself apparent at puberty during the early teenage years. Living with scoliosis can be especially difficult for children, particularly when a brace is required to stop its progression. The context of clothing physiology help a clothing system of air, vapor permeable insulation and opportunities. These same characteristics are changed when brace wearing, but also help the right materials and design concepts for the development. In view of the currently available properties of fabrics during the test and we see clothing physiology using different raw materials and functional textiles, as well as the solution for improving the body's microclimate.In our research achieve an optimal physiological state of body with a corver on the brace,that improves the body's microclimate, reduce the unpleasant effects of thebrace at high temperatures, but the basic function of the medical device support. DOI: 10.17489/biohun/2013/1/0
Tailor-made cranioplasty using CAD-CAM technologies
Get PDFTreatment of traumatic head injuries and various neurosurgical conditions sometimes includes a removal of a large part of the cranial bone. Later on, the formed crane window must be closed with an implant. In this paper we present a method that allows producing implants of any size and complexity, with accurate fit and relatively low manufacturing cost. The implants are finalized upon virtual verification and need short operations to built in the cranial bone. The method can be used also for changing existing implants. DOI: 10.17489/biohun/2013/1/1
Finite element analysis of long-time aging and sudden accidental degeneration of lumbar spine segments in compression
Get PDF3D finite element analysis of long term aging and sudden accidental degeneration processes is presented for physiologic compression load. A systematic modeling and simulation is applied for analyzing the separated and mutual effect of certain material moduli of the components of lumbar motion segments on the mechanical behaviour and stability of the segment during the long time and sudden degeneration processes. It was concluded that due to their smallest stiffness the younger segments with light degeneration are the most vulnerable during both the long-time age-related and the sudden overload-related degeneration. DOI: 10.17489/biohun/2013/1/2
Instrument development for acetabular roof plasty in case of dysplastic acetabular replacement
Get PDFThe authors report on the development of special surgical instruments required for the new Intraosseal Structural Graft (ISG) technique in case of dysplastic acetabular replacement presently under introduction at our Institute. One of novelties of procedure is the development of a proximally hinged cortico-spongious plate in the cranial quadrant of the acetabulum that is opened laterally. The instruments were developed, tested, and modified based on experiments on 14 3D models and 19 cadaver hips. For the cortico-spongious plate a 1 and 3 step method was developed and the prototypes of the chisels required were made. The open the bone block laterally a threaded device was planned and developed.Based on the experiments the 1 step method was discarded, because the device used for opening the bone block laterally proved difficult, and so it was not further developed. The instruments required for the 3 step method was finalized and since than 2 successful opera-tions were performed with them. With the aid of these special surgical instruments the ISG technique is easier, quicker and safer to perform. DOI: 10.17489/biohun/2012/1/04The authors report on the development of special surgical instruments required for the new Intraosseal Structural Graft (ISG) technique in case of dysplastic acetabular replacement presently under introduction at our Institute. One of novelties of procedure is the development of a proximally hinged cortico-spongious plate in the cranial quadrant of the acetabulum that is opened laterally. The instruments were developed, tested, and modified based on experiments on 14 3D models and 19 cadaver hips. For the cortico-spongious plate a 1 and 3 step method was developed and the prototypes of the chisels required were made. The open the bone block laterally a threaded device was planned and developed.Based on the experiments the 1 step method was discarded, because the device used for opening the bone block laterally proved difficult, and so it was not further developed. The instruments required for the 3 step method was finalized and since than 2 successful opera-tions were performed with them. With the aid of these special surgical instruments the ISG technique is easier, quicker and safer to perform.
Changes in dynamic balancing during the first six postoperative months using different surgical approaches in total hip arthroplasthy
Get PDFA jelen kutatás célja annak megállapítása, hogy ultrahang-alapú, hirtelen irányváltoztatási teszttel modellezett dinamikus egyensúlyozó képesség hogyan változik a posztoperatív időszak első hat hónapjában a különböző (antero-lateral - AL, direkt-lateral - DL és hátsó, tokmegtartó - P) feltárás esetén. 25 DL-feltárású, 22 AL-feltárású és 25 P-feltárású csípőízületi protézis beültetésen átesett beteg dinamikus egyensúlyozó képességét vizsgáltuk hirtelen, ultrahang-alapú irányváltoztatási teszttel a műtétet megelőzően, majd a posztoperatív időszak 6., 12. hetében és a 6. hónapban. A kontrollcsoportot 45 azonos korú, egészséges személy adta. A dinamikus egyensúlyozó képességet két lábon, érintett és nem-érintett oldalon történő mérés eredményeiből számított Lehr-féle csillapítási számmal jellemeztük. DL- és AL feltárás esetén a Lehr-féle csillapítási szám a posztoperatív 6. héten szignifikánsan csökken a beültetés előtt meghatározott értékekhez képest, de utána folyamatosan nő. Az érintett oldalon történő állás közben mért értékekből számított Lehr-féle csillapítási szám a posztoperatív időszak 6. hónapjában is szignifikánsan kisebb, mint a kontrollcsoport értékei. P-feltárás esetén a posztoperatív időszakban a Lehr-féle csillapítási szám folyamatosan növekszik, és a posztoperatív időszak 6. hónapjában megegyezik a kontrollcsoport értékeivel. A DL- és AL-feltárással műtött betegek esetén a posztoperatív időszak első hat hónapjában a dinamikus egyensúlyozó képesség folyamatosan javul, de az érintett oldal dinamikus egyensúlyozó képessége eltér a kontrollcsoportétól. A hátsó, tokmegtartásos feltárás esetén a dinamikus egyensúlyozó képesség javulása gyorsabb az előző két feltárási módhoz képest, és a posztoperatív időszak 6. hónapjára a kontrollcsoport egyensúlyozó képességétől szignifikánsan nem tér el. A rehabilitációs protokollok összeállításánál az ízületi mozgástartományok növelése, az izmok fejlesztése mellett hangsúlyt kell fektetni a dinamikus egyensúlyozó képesség fejlesztésére is. A dinamikus egyensúlyozó képesség fejlesztésekor, illetve a segédeszközök elhagyásakor a feltárási mód okozta különbségeket figyelembe kell venni. DOI: 10.17489/biohun/2012/1/02 The aim of our study was to detect the changes in dynamic balancing –modeled with ultrasound-based sudden perturbation test — during the first six months of the postoperative period in case of different (antero-lateral - AL, direct-lateral - DL and posterior, capsule preserving – P) surgical approaches. The dynamic balancing ability was detected with ultrasound-based sudden perturbation test before total hip arthroplasthy, and 6, 12 weeks and 6 months postoperatively in 25 patients with DL-approach, 22 patients with AL-approach and 25 patients with P-approach. The control group was formed by 45 age-matched healthy individuals. The dynamic balancing ability was characterized by the Lehr’s damping ratio that was calculated from the results of the measurements data of standing on both-, affected-, and contra-lateral lower extremity. In the sixth postoperative week, in the case of DL-, and AL approach the Lehr’s damping ratio decreased significantly comparing with the preoperative period, but after that it increased continuously. The Lehr’s damping ratio calculating from data measured during standing on affected lower extremity was significantly less as well in the sixth postoperative month, comparing to data of healthy individuals. During the postoperative period, the Lehr’s damping ratio increased continuously in case of P-approach, and in the sixth postoperative month it was equal to the control group. During the first six postoperative months, the dynamic balancing ability improved at groups operated by DL-, and AL approach, but the dynamic balancing ability of affected side differed from the control group. The improvement of dynamic balancing ability was faster at group with capsule-preserving P-approach than at the other two groups, and in the sixth postoperative month, it didn’t differ significantly from the dynamic balancing ability of the control group. To sum it up, we can see that beside improving of muscle forces and the range of motion of hip joint, the improvement of dynamic balancing ability must be taken into consideration too when planning rehabilitation protocols and also in the case of abandonment of crutches
Human-centered robotics - Biomechanics & Safety Laboratory of the Robotics and Mechatronics Center
Get PDFDOI: 10.17489/biohun/2012/1/0
The influence of knee prosthesis for the balancing ability after sudden perturbance in the early postoperative period
Get PDFA hirtelen irányváltoztatás utáni egyensúlyozó képesség a térdízületi kopás következtében romlik. Felmerült az a kérdés, hogy a térdízületi protézis beültetés utáni korai posztoperatív időszakban a hirtelen irányváltoztatás utáni egyensúlyozó képesség javul-e és a javulás ütemét a feltárás módja befolyásolja-e. Az egyik csoport esetén hagyományos feltárással, a másiknál navigált minimál invazív feltárással végezték a térdízületi endoprotézis beültetést. A dinamikus egyensúlyozó képesség modellezése a hirtelen irányváltoztatási teszttel történt, melyet rugókkal a kerethez rögzített merev lappal végeztünk. A vizsgált személy két lábon vagy egy lábon a merev lapon állt, majd a merev lap rögzítését feloldottuk. A merev lap mozgása csillapított lengőmozgás, mely a Lehr-féle csillapítási számmal jellemezhető. A csillapítást a vizsgált személy egyensúlyozó képessége adja, az egyensúlyozó képességet numerikusan a Lehr-féle csillapítási szám jellemzi. A vizsgálatot a műtét előtt, majd a műtét után 6, 12 héttel végeztük. A két betegcsoport értékeit összehasonlítva megállapítható, az egyensúlyozó képesség fejlődésének ütemét lényegesen befolyásolja a feltárás módja: a navigált, minimál invazív feltárással műtött betegek egyensúlyoóz képessége jobb . De az eredmények arra is felhívják a figyelmet, hogy a korai posztoperatív szakaszban az elesés kockázata növekedett. DOI: 10.17489/biohun/2012/1/06The balancing ability after sudden perturbance deteriorates in case of osteoarthritis. The question is if in the early postoperative period after total knee arthroplasty the balancing ability after sudden perturbance develops and how this development is influenced by the operating technique. One group of patients was operated by traditional, the other group by minimal invasive navigated method. Modeling the dynamic balancing by the sudden perturbance test was performed by a rigid plate which was fixed by springs to a frame. The subject stood on one or both legs when the plate was unexpectedly released. The movement of the rigid plate is a damped swinging movement, which can be defined by the damping ratio. The damping is achieved by the investigated subject’s balancing ability and the balancing ability is defined by the damping ratio. The measurement was performed before and 6 and 12 weeks after the operation. Comparing the values of the two patient groups it seems that the speed of balancing ability improvement is influenced by the method of exposure. The navigated minimally invasive exposure turns out to be more favourable. The results indicate that the risk of falls is increased in the early postoperative period