Axial deviation in total knee arthroplasty--is the navigation system necessary?

BACKGROUND: The aims of the total knee arthroplasty are to reduce or completely relieve pain and improve mobility of the affected joint. In the last decade navigation systems based on computer and infrared camera technology are developing quickly as an alternative to conventional surgical navigation techniques. METHODS: We compare post-operative results in 2 groups of patients after total knee arthroplasty. The groups consist of patients operated with the navigation system performing total knee arthroplasty compared with another group patients where we implanted the total knee arthroplasty using mechanical navigation system for bone resection. All patients suffered from gonarthrosis grade III or IV and had pre-operative axial deformity of the mechanical axis in the knee more than 10 degrees. Post-operative follow up X-ray was aimed to establish the mechanical axis of the limb (Mikulicz line). Statistical analysis was directed on testing the difference between two groups using the method of Mann-Whitney non-parametric test. RESULTS: Using the computerised navigation system we achieved excellent or good result in as much as 94% patients; whereas using the conventional navigation such results were in 87%. It was delightful to find that using the computerised navigation system we did not have any dissatisfactory result and the range of axial deformities deviating from the ideal Mikulicz line was significantly reduced. CONCLUSION: Results of our study show advantage in using the optoelectronic navigation system in total knee arthroplasty. Computerised navigation system enables exact insertion of knee components which results in longer life-span of the prosthesis (Tab. 2, Fig. 6, Ref. 19).

[Results of rehabilitation after double-sided prosthetic provision of lower limbs]. / Rehabilitationsergebnisse bei doppelseitiger prothetischer Versorgung der unteren Extremitäten.

UNLABELLED: FORMULATION OF THE QUESTION: As a problem stood the question what effect the progress in orthopedic technology during the last years had on the rehabilitation results of the persons affected and how etiology and distribution of age and sex have changed. METHOD: We post-examined 50 patients during home visits who had had double-sided amputations of lower limbs and were provided from 1985 to 1993 were examined at home. RESULTS: Etiologically it concerns 25 patients with chronic arterial circulatory disturbances, 10 with trauma, 7 with congenital damages and 8 with consequences of other amputation causes. The rehabilitation results are to be evaluated with good. It could be proved that also elder double-sided amputees can be prosthetically rehabilitated if at least one knee joint could be maintained. The physiotherapeutic post-care was recognized as the weak point of rehabilitation, it has to be improved especially for the elder persons affected. CONCLUSION: The elder double-sided amputee can be enabled to a safe walk on prostheses only by optimum rehabilitation management with quick prosthetic provision and early starting intensive physiotherapeutic post-care which should go on for a much longer time than the stay in hospital.

[Age-related changes in systematic inhomogeneities of articular cartilage]. / Alternsveränderungen systematischer Inhomogenitäten des Gelenkknorpels.

We have considered the question of the quantification of differentiation processes. We investigated articular cartilage of the Caput femoris in 22 cases aged from 0 to 77 years. We measured cell size and volume density. During aging a shifting of the layer with the maximum cell size in relation to the joint surface as well as the formation of two layers with different volume densities take place. We believe that the changes in nutritional and load conditions during life play a role in these processes. We describe these with the term "diversification", characterizing the process of the changing of the degree of structural order.

[Quantitative analysis of a differentiation characteristic of hyaline cartilage in the aging process]. / Quantitative Analyse eines Differenzierungsmerkmals des hyalinen Knorpels im Alternsgang.

Changes in the distribution patterns of chondrocytes in the permanent hyaline cartilage were studied in order to analyze a process of differentiation quantitatively. Sections of 29 specimens of arytenoid cartilage and 42 specimens of Carina tracheae from newborn up to the age of 91 years were used. The chondrocytes were transferred via a mirror to paper, and the resulting patterns were analyzed. Various distribution functions were calculated. The most important one is the pair correlation function. The behavior of the differentiation is resembling in both organs. Especially in arytenoid cartilage there were found the following results: The clearest process of differentiation took place up to the 3rd decade of life. Initial hard core distribution is followed by soft core distribution up to the final of puberty. After the 2nd decade of life clustering was found. The grade of differentiation decreases in the 5th decade of life and later.

[Quantitative analysis of cell density and pattern of chondrocytes in transitory hyaline cartilage anlagen of human tarsal bones]. / Quantitative Analyse der Knorpelzelldichte und des Chondrozytenmusters im transitorischen hyalinen Knorpel der embryonalen Anlagen menschlicher Fusswurzelknochen.

Changes in the distribution patterns of chondrocytes in the embryonic transitory hyaline cartilage of the tarsus were studied using 56 sagittal section of tarsi from 28 human embryos, with a vertex-foot length from 7.0 to 44.0 cm. The os naviculare and os cuboideum were not sliced in all sections. A total of 93,931 cells were transferred via a mirror to paper, and the resulting patterns were analyzed. Determinations included the numerical surface and volume density of the chondrocytes and the cell distribution patterns using the dispersion index. In the case of the calcaneus, talus, os naviculare and os cuboideum, the number of sliced cells found over a constant area decreases at a continuous linear rate in the course of the embryonic period. In all tarsal primordia the distribution pattern developed from regular to random. Particular conditions prevail immediately below the perichondrium and near the ossification centers which can be found in the calcaneus from the 6th month onwards.

[Quantitative analysis of chondrocyte distribution patterns in hyaline cartilage tissue--a comparison of different models]. / Quantitative Analyse von Chondrocytenverteilungsmustern im hyalinen Knorpelgewebe--Vergleich verschiedener Modelle.

The purpose of our investigations were aging changes in hyaline cartilage of the trachea and of the larynx. 42 samples of carina tracheae and 29 samples of arytenoid cartilage were used in both organs from the newborn age up to the age of 91 a. We have examined patterns of cell distribution with the help of the computer programme "Dichte" ("density") using the following methods of stochastic geometry: product density, L function, and others. Product density allows for a reliable destination between a regular pattern of cells (hard-core distribution), a random pattern (soft-core distribution), and a typical clustering of chondrocytes. 2 examples of arytenoid cartilage have been selected to demonstrate the possibilities of interpretation of product density supported by the L function. Soft-core and in few cases hard-core distribution have been found both with the carina tracheae and the cartilago arytaenoidea in the 1st decade of life. Beginning with the 2nd decade of life, the typical clustering of chondrocytes have been confirmed with both organs.

[Quantitative detection of the differentiation processes of cartilage tissue]. / Zur quantitativen Erfassung eines Differenzierungsprozesses im Knorpelgewebe.

The onset of ageing during childhood and adolescence is accompanied by a variety of differentiation processes, whereas ageing later in life is characterized by dysdifferentiation. One of the subjects in the present discussion is the "Dysdifferentiation hypothesis of ageing". So far differentiation has been described only in qualitative terms. The paper uses the example of hyaline cartilage development (chondrogenesis) to show that a quantitative approach to differentiation is possible, which at the same time enables random-critical study. The method used for this is stochastic geometry.