Thesis (doctoral)--Ludwig Maximilians-Universität zu München, 1979.

Thesis (doctoral)--Uppsala University, 1981. / At head of title: From the Department of Orthopaedic Surgery, University Hospital, Sweden. Includes bibliographical references (p. 19-20).

Thesis (doctoral)--Uppsala University, 1981. / Includes bibliographical references (p. 18-19).

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Yes / Background: Walking down ramps is a demanding task for transfemoral-amputees and terminating gait on ramps is even more challenging because of the requirement to maintain a stable limb so that it can do the necessary negative mechanical work on the centre-of-mass in order to arrest (dissipate) forward/downward velocity. We determined how the use of a microprocessor-controlled limb system (simultaneous control over hydraulic resistances at ankle and knee) affected the negative mechanical work done by each limb when transfemoral-amputees terminated gait during ramp descent. Methods: Eight transfemoral-amputees completed planned gait terminations (stopping on prosthesis) on a 5-degree ramp from slow and customary walking speeds, with the limb's microprocessor active or inactive. When active the limb operated in its ‘ramp-descent’ mode and when inactive the knee and ankle devices functioned at constant default levels. Negative limb work, determined as the integral of the negative mechanical (external) limb power during the braking phase, was compared across speeds and microprocessor conditions. Findings: Negative work done by each limb increased with speed (p < 0.001), and on the prosthetic limb it was greater when the microprocessor was active compared to inactive (p = 0.004). There was no change in work done across microprocessor conditions on the intact limb (p = 0.35). Interpretation: Greater involvement of the prosthetic limb when the limb system was active indicates its ramp-descent mode effectively altered the hydraulic resistances at the ankle and knee. Findings highlight participants became more assured using their prosthetic limb to arrest centre-of-mass velocity. / ZA is funded by the Higher Committee of Education Development in IRAQ (HCED student number D13 626).

Le but de cette thèse était d'étudier, in vivo, la cinématique en 3D du genou lors de la marche sur des patients souffrant d'arthrose du genou et de quantifier l'apport de l'arthroplastie totale du genou (PTG) sur la restauration d'une cinématique normale. Trente patients et un groupe de contrôle composé de 12 participants du même âge ont été inclus dans la première étude. Sur ces 30 patients, nous avons obtenu des évaluations de suivi après l'arthroplastie totale du genou sur 20 patients, avec un délai moyen de 11 mois. L'analyse cinématique tridimensionnelle du genou a été réalisée en utilisant le système KneeKGTM. Cette analyse de la marche a révélé que la cinématique de genou avec arthrose médiale diffère de la cinématique du genou sain. Le groupe avec arthrose du genou montrait une stratégie de raidissement de la marche en présentant une réduction de mouvement non seulement dans le plan sagittal, mais aussi dans le plan axial. Après PTG, les patients avaient de meilleurs paramètres cliniques, spatio-temporels et cinématiques. Malgré les améliorations, la cinématique du genou lors de la marche dans le groupe PTG différaient de celle du groupe contrôle / Patients with knee osteoarthritis tend to modify spatial and temporal parameters during walking to reduce the pain. There are common gait features which are consistently shown to be significantly linked to osteoarthritis severity such as knee adduction moment, knee flexion angle, stiffness and walking speed. Total knee arthroplasty (TKA) is considered the gold standard treatment for end-stage knee osteoarthritis. Nearly a million of total knee prosthesis are implanted worldwide each year. However, reduced physical function of the knee is partly, but apparently not fully, remedied by surgery. The purpose of this thesis was to investigate the in vivo, three dimensional knee kinematics during gait at the patients with knee osteoarthritis and the influence of total knee arthroplasty on restoration of normal kinematics. Weight bearing kinematics in medial OA knees differ from normal knee kinematics. Knee OA group showed an altered “screw-home” mechanism by decreased excursion in sagittal and axial tibial rotation and a posterior translation of the tibia. Following TKA, patients had better clinical, spatiotemporal and kinametic parameters. They walked longer, faster and with a better range of motion. Despite improvements, the knee kinematics during gait in TKA group differed from healthy control group. They had a lower extension, lower range of axial rotation and an increased tibial posterior translation. Future research should be focused on comparing different designs of prosthesis pre- and post operatively in a longer follow-up delay

The major objective of this thesis was to investigate how the use of a recently developed microprocessor-controlled limb system altered the negative mechanical work done by the intact and prosthetic limb when trans-femoral amputees terminated gait. Participants terminated gait on a level surface from their self-selected walking speed and on declined surface from slow and customary speeds, using limb system prosthesis with microprocessor active or inactive. Limb negative work, determined as the integral of the negative mechanical (external) limb power during the braking phase, was compared across surface, speed and microprocessor conditions. Halting gait was achieved predominantly from negative work done by the trailing/intact. Trailing versus leading limb mechanical work imbalance was similar to how able body individuals halted gait. Importantly, the negative limb work performed on the prosthetic side when terminating gait on declined surface was increased when the microprocessor was active for both slow and customary speeds (no difference on level surface) but no change on intact limb. This indicates the limb system’s ‘ramp-descent mode’ effectively/dynamically altered the hydraulic resistances at the respective joints with evidence indicating changes at the ankle were the key factor for increasing the prosthetic limb negative work contribution. Findings suggest that trans-femoral amputees became more assured using their prosthetic limb to arrest body centre of mass velocity when the limb system’s microprocessor was active. More generally findings suggest, trans-femoral amputees should obtain clinically significant biomechanical benefits from using a limb system prosthesis for locomotion involving adapting to their everyday walking where adaptations to an endlessly changing environment are required. / Higher Committee of Education Development in IRAQ (HCED)

<p>Uvod Napredak hirur&scaron;kih i anesteziolo&scaron;kih tehnika učinio je hirur&scaron;ku intervenciju ugradnje totalne proteze kolena uspe&scaron;nom i bezbednom. Međutim, po&scaron;to spada u opsežne ortopedske intervencije, praćena je značajnim gubicima krvnog volumena, kao i značajnom potro&scaron;njom krvi i krvnih derivata. Trendovi u savremenoj medicini idu u pravcu restrikcije upotrebe krvi i krvnih derivata i čine se veliki napori u istraživanju i razvijanju metoda i tehnika koje mogu biti alternative alogenoj transfuziji krvi. Traneksamična kiselina koja ima antifibrinolitičko dejstvo, može dovesti do značajnog smanjenja perioperativnog krvarenja. Ciljevi istraživanja su bili utvrđivanje uticaja traneksamične kiseline na perioperativno krvarenje kod operacija ugradnje totalne proteze kolena, kao i utvrđivanje postojanja uticaja traneksamične kiseline na perioperativnu upotrebu alogene krvi kod operaacija ugradnje totalne proteze kolena. Matrijal i metode u studiju je bilo uključeno 96 bolesnika oba pola, starijih od 18 godina, kojima je bila ugrađivana primarna elektivna totalna proteza kolena. Oni su bili podeljeni u dve grupe, 48 u ispitivanoj grupi kod kojih je primenjivana traneksamična kiselina i 48 bolesnika koji su bili kontrolna grupa. Svi bolesnici su bili u spinalnoj anesteziji i primenjivana je pneumatska poveska na ekstremitetu koji se operisao. Ispitivana grupa je dobijala traneksamičnu kiselinu u dva navrata u dozi od 15 mg /kg i 10 mg/kg u vidu kontinuirane i.v. infuzije u trajanju od 15 minuta. Prvo davanje leka je bilo neposredno nakon uvoda u anesteziju. Drugo davanje leka je bilo 15 minuta pre otpu&scaron;tanja pneumatske poveske. Kontrolna grupa je dobijala istu količinu 0.9% fiziolo&scaron;kog rastvora koji je primenjivan na isti način. Intraoperativni gubitak krvi je beležen i meren kao gubitak u aspiratoru i gubitak na gazama. Postoperativn gubitak krvi se merio nakon 6, 12 sati i nakon 24 sata, kao gubitak na drenove Beležio se i broj primenjenih jedinica krvi i broj ukupno dobijenih mililitara krvi i ostalih krvnih produkata, kao i vreme njihove primene. Rezultati Postoji statistički značajna razlika u prosečnom intraoperativnom krvarenju između grupa (Z = -7,281; p = 000). Prosečno intraoperativno krvarenje u ispitivanoj grupi je bilo 100 &plusmn; 92,690 ml, a u kontrolnoj 447 &plusmn; 299,282 ml. U kontrolnoj grupi bolesnici imaju statistički značajno veće ukupno postoperativno krvarenje od bolesnika iz ispitivane grupe (T test, t=4,024, p&lt;0,01) ( ispitivana grupa 309,78&plusmn; 143,612 ml, kontrolna grupa 455,42 &plusmn; 201,177 ml). Razlika je bila statistički značajna nakon 6 sati (p &lt; 001) i nakon 12 sati u korist ispitivane grupe (p&lt;0,05). Postji statistički značajna razlika u ukupnom perioperativnom krvarenju među grupama i traneksamična kiselina je statistički značajno (p&lt;0,000) smanjila ukupno krvarenje од 919,36 ml (95%IP 822,083-1016,640) na 405, 32 ml (95% IP 353, 407-457, 231). Ukupno perioperativno krvarenje je u proseku iznosilo 662, 34 ml i kretalo se u intervalu od 100 do 1700 ml. U ispitivanoj grupi je samo 5 (10,4%) ispitanika primilo transfuziju, dok je u kontrolnoj grupi 39 (81,3%), &scaron;to je statistički značajna razlika (2=45,692; p=0,000). Prosečna količina date alogene krvi u ispitivanoj grupi je 33,33 &plusmn; 99,2 ml, dok je prosečna količina date alogene krvi u kontrolnoj grupi bila skoro deset puta veća i iznosila je 319,2 &plusmn; 230 ml, &scaron;to je statistički značajno veće (Z = -6,625; p = 000). Postoperativne vrednosti hemoglobina, hematokrita i trombocita bile su statistički značajno veće u isptivanoj grupi. Bolesnici iz ispitivane grupe su statistički značajno ranije postoperativno uzimali prvi obrok, sedeli i ustajali od bolesnika u kontrolnoj grupi. Zaključci Iz dobijenih rezultata o intraoperativnom, postoperativnom i ukupnom perioperativnom krvarenju može se zaključiti da je traneksamična kiselina veoma efikasan lek i da statistički značajno smanjuje krvarenje vezano za ugradnju totalne proteze kolena i da smanjuje upotrebu transfuzije alogene krvi za 66,7%. Traneksamična kiselina je uticajem na smanjenje perioperativnog krvarenja dovela do očuvanja vrednosti hemoglobina, hematokrita i trombocita. Bolesnici koji su dobijali traneksamičnu kiselinu su takođe imali brži i kvalitetniji neposredni postoperativni oporavak.</p> / <p>Uvod Napredak hirur&scaron;kih i anesteziolo&scaron;kih tehnika učinio je hirur&scaron;ku intervenciju ugradnje totalne proteze kolena uspe&scaron;nom i bezbednom. Međutim, po&scaron;to spada u opsežne ortopedske intervencije, praćena je značajnim gubicima krvnog volumena, kao i značajnom potro&scaron;njom krvi i krvnih derivata. Trendovi u savremenoj medicini idu u pravcu restrikcije upotrebe krvi i krvnih derivata i čine se veliki napori u istraživanju i razvijanju metoda i tehnika koje mogu biti alternative alogenoj transfuziji krvi. Traneksamična kiselina koja ima antifibrinolitičko dejstvo, može dovesti do značajnog smanjenja perioperativnog krvarenja. Ciljevi istraživanja su bili utvrđivanje uticaja traneksamične kiseline na perioperativno krvarenje kod operacija ugradnje totalne proteze kolena, kao i utvrđivanje postojanja uticaja traneksamične kiseline na perioperativnu upotrebu alogene krvi kod operaacija ugradnje totalne proteze kolena. Matrijal i metode u studiju je bilo uključeno 96 bolesnika oba pola, starijih od 18 godina, kojima je bila ugrađivana primarna elektivna totalna proteza kolena. Oni su bili podeljeni u dve grupe, 48 u ispitivanoj grupi kod kojih je primenjivana traneksamična kiselina i 48 bolesnika koji su bili kontrolna grupa. Svi bolesnici su bili u spinalnoj anesteziji i primenjivana je pneumatska poveska na ekstremitetu koji se operisao. Ispitivana grupa je dobijala traneksamičnu kiselinu u dva navrata u dozi od 15 mg /kg i 10 mg/kg u vidu kontinuirane i.v. infuzije u trajanju od 15 minuta. Prvo davanje leka je bilo neposredno nakon uvoda u anesteziju. Drugo davanje leka je bilo 15 minuta pre otpu&scaron;tanja pneumatske poveske. Kontrolna grupa je dobijala istu količinu 0.9% fiziolo&scaron;kog rastvora koji je primenjivan na isti način. Intraoperativni gubitak krvi je beležen i meren kao gubitak u aspiratoru i gubitak na gazama. Postoperativn gubitak krvi se merio nakon 6, 12 sati i nakon 24 sata, kao gubitak na drenove Beležio se i broj primenjenih jedinica krvi i broj ukupno dobijenih mililitara krvi i ostalih krvnih produkata, kao i vreme njihove primene. Rezultati Postoji statistički značajna razlika u prosečnom intraoperativnom krvarenju između grupa (Z = -7,281; p = 000). Prosečno intraoperativno krvarenje u ispitivanoj grupi je bilo 100 &plusmn; 92,690 ml, a u kontrolnoj 447 &plusmn; 299,282 ml. U kontrolnoj grupi bolesnici imaju statistički značajno veće ukupno postoperativno krvarenje od bolesnika iz ispitivane grupe (T test, t=4,024, p&lt;0,01) ( ispitivana grupa 309,78&plusmn; 143,612 ml, kontrolna grupa 455,42 &plusmn; 201,177 ml). Razlika je bila statistički značajna nakon 6 sati (p &lt; 001) i nakon 12 sati u korist ispitivane grupe (p&lt;0,05). Postji statistički značajna razlika u ukupnom perioperativnom krvarenju među grupama i traneksamična kiselina je statistički značajno (p&lt;0,000) smanjila ukupno krvarenje od 919,36 ml (95%IP 822,083-1016,640) na 405, 32 ml (95% IP 353, 407-457, 231). Ukupno perioperativno krvarenje je u proseku iznosilo 662, 34 ml i kretalo se u intervalu od 100 do 1700 ml. U ispitivanoj grupi je samo 5 (10,4%) ispitanika primilo transfuziju, dok je u kontrolnoj grupi 39 (81,3%), &scaron;to je statistički značajna razlika (2=45,692; p=0,000). Prosečna količina date alogene krvi u ispitivanoj grupi je 33,33 &plusmn; 99,2 ml, dok je prosečna količina date alogene krvi u kontrolnoj grupi bila skoro deset puta veća i iznosila je 319,2 &plusmn; 230 ml, &scaron;to je statistički značajno veće (Z = -6,625; p = 000). Postoperativne vrednosti hemoglobina, hematokrita i trombocita bile su statistički značajno veće u isptivanoj grupi. Bolesnici iz ispitivane grupe su statistički značajno ranije postoperativno uzimali prvi obrok, sedeli i ustajali od bolesnika u kontrolnoj grupi. Zaključci Iz dobijenih rezultata o intraoperativnom, postoperativnom i ukupnom perioperativnom krvarenju može se zaključiti da je traneksamična kiselina veoma efikasan lek i da statistički značajno smanjuje krvarenje vezano za ugradnju totalne proteze kolena i da smanjuje upotrebu transfuzije alogene krvi za 66,7%. Traneksamična kiselina je uticajem na smanjenje perioperativnog krvarenja dovela do očuvanja vrednosti hemoglobina, hematokrita i trombocita. Bolesnici koji su dobijali traneksamičnu kiselinu su takođe imali brži i kvalitetniji neposredni postoperativni oporavak.</p> / <p>Introduction: Total knee arthroplasty today is efficient and safe surgical procedure. Being extensive orthopaedic surgical procedure poses a risk from substantial perioperative bleeding and consecutive usage of blood products.&nbsp; Trends in modern medicine and surgery are in favor of restrictive usage of blood products and there are paramount efforts in researching and developing new techniques and methods of allogenic blood transfusion alternatives. Tranexamic acid as fibrinolytic agent is good example of substance that can be used to reduce preoperative bleeding in orthopaedic surgery. Aims of the study: We wanted to explore effects of tranexamic acid on perioperative bleeding reduction in total knee arthroplasty, and it&rsquo;s effect on reduction of blood product usage in this surgical population. Маterial and methods: We conducted double blind, randomized controlled trial with 96 adult patient (older than 18 years) in the study, 48 in two groups. All patients had elective, unilateral total knee arthroplasty. First group got tranexamic acid(TA), and second (control) group got normal saline. Surgery was performed in spinal anaesthesia with usage of pneumatic tourniquet in all patients. First group got tranexamic acid 15mg /kg/ bw и 10 mg/kg/bw as continuous intravenous infusion in duration of 15 min. Control group got same amount of normal saline. First dose of TA was given at the beginning of the operation and second dose 15 min before release of the tourniquet. Control group got normal saline at the same way. Intraoperative blood loss was measured as blood loss in suction bottle and blood loss on the surgical sponges. Postoperative blood loss was measured as blood loss in surgical wound drains after 6, 12, and 24 hours. Number of blood units and total amount of blood and blood products in milliliters were also recorded. Results There are statistically significant difference in average intraoperative bleeding between groups in favor tranexamic acid group (Z = -7,281; p = 000).Average intraoperative bleeding in TA group is 100 &plusmn; 92,690 mil, vs 447 &plusmn; 299,282 mil in control group. Patient in TA group has statistically significant less total postoperative bleeding (T test, t=4,024, p&lt;0,01)( TA group 309,78&plusmn; 143,612 mil vs,420 &plusmn; 201,177 mil). Blood loss was statistically significant less after 6 (p &lt; 001) and 12 hrs (p &lt;0,05). in TA group. Total perioperative bleeding was statistically significant less (p&lt; 0,000) in TA group and TA decreased total blood loss from 919,36 ml (95%IP 822,083-1016,640) to 405,32 ml (95%IP 353,407-457,231).Average total blood loss was 662,34 ml with interval from 100 to 1700 ml. In TA group only 5 (10,4%) patients received vs control group where 39 (81,3%) patients received allogenic blood transfusion and that is statistically significant (2=45,692; p=0,000).Average blood usage in TA group was 33,33 &plusmn; 99,2 ml vs 319,2 &plusmn; 230 ml in the control group (Z = -6,625; p = 000). Postoperative hemoglobin, haematocrit and platelets count values were statistically significant less in control group. Patient in TA group had earlier first postoperative meal, sitting and standing earlier than patient in the control group. Concliusions Data from this study clearly shows that intraoperative, postoperative and total perioperative blood loss in total knee arthroplasty are reduced with usage of tranexamic acid. Tranexamic acid is effective in reducing perioperative blood loss and usage of allogenic blood transfusion, which dropped for 66,7%.This reduced blood loss led to higher postoperative hemoglobin levels. Patients from TA group showed faster postoperative functional recover.</p>

Une prothèse de genou est généralement, composée de deux parties fixées respectivement sur le fémur et sur le tibia et d’une troisième, dite intercalaire. Durant le processus de fabrication de ces composants des déformations apparaissent au niveau des bruts de fonderie. Les fabricants de prothèses choisissent d’assurer l’épaisseur nominale de la prothèse en enlevant une épaisseur constante sur le brut de fonderie. Cette opération est généralement réalisée manuellement. L’objectif de ces travaux de thèse est de contribuer à l’automatisation de ces opérations en proposant une méthode d’adaptation des trajectoires d’usinage aux variations géométriques de la surface cible. L’objectif de ce travail de recherche est d’adapter une trajectoire d’usinage sur un modèle nominal pour enlever une épaisseur constante sur une surface brute de fonderie mesurée. La méthode proposée commence par une étape d’alignement de la surface mesurée sur la trajectoire nominale en utilisant un algorithme d’ICP. Par la suite, la trajectoire nominale est déformée pour venir enlever l'épaisseur désirée sur la surface brute mesurée. Cette dernière est définie, dans ces travaux, suivant un modèle STL. Naturellement, les discontinuités de ce type de modèle induit une impression des motifs du STL sur la trajectoire adaptée et, donc, sur la pièce usinée. Par la suite, afin de d’atténuer ce problème et d’améliorer la qualité de fabrication, il est proposé de procéder à un lissage de la trajectoire.Afin de valider les développements théoriques de ces travaux, des essais ont été réalisés sur une machine cinq axes pour l’ébauche de composants fémoraux d’une prothèse uni-compartimentale de genou. / Commonly, knee prostheses are composed of two parts fixed respectively on femur and tibia, and a third one called intercalary. During the manufacturing process, of these components distortions appear on roughcast workpiece geometry. Thus, prosthesis manufacturers choose to ensure the nominal thickness of the prosthesis by removing a constant thickness on the roughcast workpiece. This operation is generally carried out realized manually.The aim of this thesis is to contribute to the automation of these manual operations by providing a method to adapt the machining toolpaths at geometrical variations of the target surface. The aim of this research work is to adapt a machining toolpath computed on a nominal model to remove a constant thickness on a roughcast measured surface. The proposed method starts with an alignment step of the measured surface on the nominal toolpath using an ICP algorithm. Subsequently, the nominal toolpath is deformed to remove the desired thickness of the measured rough surface defined in presented case by a STL model. Naturally, discontinuities of this type of model induce the apparition of pattern for the STL on the adapted toolpath and thus on the machined workpiece. Subsequently, to limit this problem and to improve the quality of realized surface, it is proposed a toolpath smoothing method. To validate theoretical developments of this work, tests were carried out on a five-axis machine for roughing of femoral components of a unicompartmental knee prosthesis.

Abstract A variety of radiopharmaceuticals and imaging techniques are currently available for scintigraphic imaging of infections. However, comparisons on the clinical value of such techniques have been limited, especially in prosthesis infections. This series included 138 cases with suspected prosthesis infections – 94 in hip and 44 in knee prostheses of patients whose final diagnoses were based on clinical, operative and microbiological findings, and who underwent three-phase bone, 99mTc -leukocyte and 99mTc-ciprofloxacin imaging in the Department of Clinical Chemistry, Oulu University Hospital and in the Laboratory, L?nsi-Pohja Central Hospital, during the years from 1993 to 2001. The normal arterial and soft-tissue phase images of three-phase bone imaging practically excluded infection in hip prostheses, whereas these techniques frequently yielded false positive findings in patients with knee prostheses, resulting in specificity of 23% or less. In combined 99mTc-leukocyte/bone imaging, diagnostic accuracy was 80–86% at two- to four-hour images and 87–98% at 24-hour images. The 99mTc-ciprofloxacin images showed unspecific accumulation of tracer in the one-hour and four-hour images, which disappeared in the 24-hour images in most hip and knee prostheses. 99mTc-ciprofloxacin imaging yielded almost as good diagnostic accuracy as combined 99mTc-leukocyte/bone imaging. In conclusion, in suspected hip prosthesis infections, normal findings in three-phase bone imaging exclude infection, whereas abnormal results in the arterial and soft-tissue phases should be confirmed with 99mTc-leukocyte imaging using 24-hour images. Contrary-wise, in suspected knee prosthesis infections, 99mTc-leukocyte imaging with 24-hour images is the first-line examination, and abnormal results in 24-hour images should be confirmed by using 99mTc-bone-metabolic imaging. 99mTc-ciprofloxacin yielded almost equally good results as 99mTc-leukocyte/bone-metabolic imaging, but unfortunately, the tracer is not commercially available, although it has been patented.