Purpose: The aim of this work was to evaluate postural stability on the balance platform averagely 2 years following meniscal repair. Methods: This is a retrospective, case-control comparative analysis of patients who underwent surgical repair for the isolated longitudinal traumatic meniscal tear versus matched healthy controls. The study group consisted of 30 patients (mean age 29.93 years; averagely 2.3 years after surgery) and the control group – of 30 people. Following physical examination and completion of the IKDC, and the Lysholm questionnaires, the evaluation of the postural stability using two single-leg stabilometry tests was performed. In the static test, the analyzed variables included deviations from the horizontal, vertical axes and the length of the balance path travelled. In the dynamic test, the length of the path travelled and the time to complete task were recorded. Between-limb and between-groups comparison of collected stabilometry tests were performed. Additionally, the IKDC and the Lysholm questionnaires scores were compared between the study and heathy groups. Results: No abnormalities were found on clinical examination in the study group nor any differences between the operated and contralateral knee (p > 0.05). In stabilometry: (1) in the study group, the operated extremity scored worse than the contralateral limb (length of path traveled in: A) static test x = 56.7 cm SD = 37.91 cm vs. x = 21.6 cm SD = 9.06 cm; p = 0.002 and B) dynamic test x = 82.57 cm, SD = 50.43 cm vs. x = 53.32 cm, SD = 13.82 cm; p = 0.003); (2) In the control group, no leg-related differences were noted (p > 0.05); (3) Between-group comparison revealed that the study group scored worse than the control group (length of path traveled in: A) static test x = 56.7 cm, SD = 37.91 cm vs. x = 17.23 cm, SD = 3.39 cm; p = 0.001 and B) dynamic test x = 82.57 cm, SD = 50.43 cm vs. x = 32.13 cm, SD = 9.41 cm; p < 0.001). Study group scored worse on IKDC scores (p < 0.001) but not on Lysholm score ( p > 0.05). Conclusions: Postural stability deficit persists despite a successful meniscal repair.
Kolano jest układem wylotowym kanału przepływowego sprężarki promieniowej i osiowo-odśrodkowej, w którym następuje zmiana kierunku przepływu z promieniowego na kierunek wyznaczony przez oś dyfuzora komory spalania. W pracy przedstawiono metodę wyznaczania parametrów strumienia w przekroju wyjściowym układu wylotowego sprężarki promieniowej i osiowo-odśrodkowej. Analiza obejmuje układ wylotowy typu kolana. Zaprezentowano także odpowiednią metodę określania parametrów geometrycznych dla kanału wylotowego tego typu. Wymienione metody mogą być stosowane w trakcie realizacji projektu koncepcyjnego sprężarki, a oparto je na równaniu zachowania energii, równaniu ciągłości przepływu, pierwszej i drugiej zasadzie termodynamiki oraz funkcjach gazodynamicznych i definicjach używanych w teorii maszyn wirnikowych. Końcowa część pracy zawiera zasady doboru obliczeniowej wartości sprężu sprężarki z promieniowym dyfuzorem łopatkowym oraz wnioski.
The objective of the study was assessment of the function of the knee joint after ACL reconstruction using the LARS method and autogenous graft. The study was of a retrospective character and included 96 patients who had undergone reconstruction of the torn ACL. The study was conducted within 36–48 months after surgery. Methods: In order to compare the results of the ACL reconstruction performed with 2 types of grafts, the following instruments were used: Lysholm Knee Scoring Scale, SF 36v2 questionnaire for assessment of health-related quality of life, and Biodex System 4 for isokinetic muscle testing. Results: No differences in the evaluation of the quality of life measured using SF 36v2 questionnaire were observed between the LARS and ST GR groups. Using the Lysholm Scale, the distribution of knee function scores was compared according to the type of surgery. There are no grounds to confirm the differences in the distribution of knee function scores considering the type of graft ( p = 0.756). Isokinetic test showed a significant weakening of muscle strength in the operated limb, compared to the strength of the healthy limb. Conclusions: The type of graft used for ACL reconstruction does not exert an effect on the quality of life of patients or the level of their knee joint function. Extensor and flexor muscles strength of the knee joint was lower in the operated limb, irrespective of the type of graft used. Weak relationships were observed between the level of knee joint function and extensor muscle strength of this joint.
The aim of the study was to assess static balance after reconstruction of the anterior cruciate ligament (ACL), using gracialis tendons graft (GR) or semi-tendinosus (ST), compared to patients treated with the Ligament Advanced Reinforcement System (LARS). The study was performed within 36 to 48 months after the surgery. Methods: The study included 96 patients. The LARS group consisted of 44 patients, control group operated with ST/GR tendons included 52 patients. The stabilometric platform Alpha was used to assess the static balance. Two 30-second trials in the double-leg stance position with eyes opened and closed were performed. The distribution of loads in a free standing was also assessed. Results: In the test with open eyes the subjects from the LARS group had a significantly longer center of pressure (COP) path, a higher mean velocity, a greater mean COP sway in foot in the lateral direction and a larger path area occupied by the COP graph. During the tests with eyes closed, a significant difference occurred in the mean displacement of COP in lateral direction – greater in the LARS group. In addition, all parameters deteriorated during the tests with eyes closed in both groups. Conclusions: In static balance assessed with eyes closed, more proprioceptive deficits may appear in the LARS group.
Purpose: In comparative examinations of kinematics of the knees of humans and pigs in flexional/extensional motion under compressive loads, the significant differential geometric essentials of articular guidance are elaborated to criticise the shaping of the articular surfaces of conventional knee-endoprostheses and to suggest constructional outlines that allow the endoprosthesis to adopt natural knee kinematics. Implantation is discussed with regard to the remaining ligamentous apparatus. Methods: Twelve fresh pig knee joints and 19 preserved human knee joints were moved into several flexional/extensional positions. In each joint, the tibia and femur were repeatably caught by metal plates. After removing all ligaments, the tibia and femur were again caught in these positions, and their points of contact were marked on both articular surfaces. Along the marker points, a thin lead wire was glued onto each surface. The positions and shapes of the four contact lines were mapped by teleradiography. Results: All contact lines were found to be plane curves. The medial and lateral planes were parallel, thus defining the joint’s sagittal plane. In the human knee, as compared to the lateral, the medial femoral contact line was always shifted anteriorly by several millimetres. The tibial contact curve was laterally convex and medially concave. In the pig knees, the lateral and medial contact lines were asymmetrically placed. Both tibial curves were convex. Conclusions: Both knees represent cam mechanisms (with one degree of freedom) that produce rolling of the articular surfaces during the stance phase. Implantation requires preservation of the anterior cruciate ligament, and ligamentous balancing is disadvantageous.
Endoprotezoplastyka jest obecnie podstawową metodą leczenia osób z zaawansowanymi zmianami zwyrodnieniowymi stawu kolanowego. Głównym celem zabiegu jest redukcja dolegliwości bólowych, poprawa zakresu ruchomości oraz przywrócenie stabilności stawu, co ma doprowadzić do polepszenia jakości życia chorych. Celem pracy była ocena efektów usprawniania pacjentów po wszczepieniu jedno- lub wieloosiowej endoprotezy stawu kolanowego. Badaniem objęto grupę 60 osób (45 kobiet i 15 mężczyzn) z zaawansowaną gonartrozą. Średnia wieku wynosiła 66,4 lata. 30 pacjentom wszczepiono jednoosiową endoprotezę SCORPIO CR a pozostałym 30 pacjentom endoprotezę wieloosiową PFC SIGMA. We wszystkich przypadkach zachowano więzadło krzyżowe tylne PCL (ang. Posterior Cruciate Ligament). Program leczenia usprawniającego we wczesnym okresie pooperacyjnym był taki sam u wszystkich chorych. Po około 3 miesiącach od zabiegu pacjenci byli usprawniani na Oddziale Rehabilitacji Narządu Ruchu przez okres 3 tygodni, korzystając z odpowiednio dobranego programu kinezy- i hydroterapii. Oceny zakresu ruchomości stawu kolanowego dokonano przed zabiegiem operacyjnym oraz po zakończeniu rehabilitacji. Wyniki wskazują na poprawę zakresu zgięcia oraz wyprostu operowanego stawu, zarówno u pacjentów z jedno-, jak i wieloosiowym implantem.
EN
Total arthroplasty is currently the main treatment of patients with advanced knee degeneration. The basic goal of the surgery is to reduce pain, improve range of motion (ROM), restore join stability, what can lead to the improved quality of life.The aim of this study was to examine the effects of rehabilitation of patients after single- or multi-axis total knee arthroplasty (TKA). The research was performed on a group of 60 people (45 women and 15 men) with advanced gonarthrosis (mean age 66,4 years). In 30 patients single-axis SCORPIO CR prostheses and in 30 multi-axis PFC Sigma prostheses, were implanted. In all cases the posterior cruciate ligament (PCL) has been retained. Physical therapy in the immediate postoperative period was the same in all groups. The patients were exposed to kinesi- and hydrotherapy 3 months after surgery. The functional status of the knee before surgery and after rehabilitation, were evalutaed. It was stated that the knee flexion and extension were improved. There was no significant difference between these 2 groups.
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The aim of the study was to evaluate the torque of the shank rotating muscles in patients with reconstructed anterior cruciate ligament (ACL) and rehabilitation accomplished in comparison with a control group. The study was carried out on the group of 187 males. For the purpose of the study a prototype testing device for the shank rotating muscles' torque under static conditions was used. The study was based on the measurement of maximal torque at selected angles (-30 degree, 0 degree, 45 degree) of the shank rotation as well as on the angle (30 degree, 60 degree, 90 degree) of flexion of the knee joint. The results obtained in the group with reconstructed anterior cruciate ligament (ACL) and rehabilitation accomplished were comparable to those the control group and mostly of no statistical significance. Lack of significant differences between the values of shank rotating muscles' torque achieved in an injured limb compared to an uninjured one may testify to an effective rehabilitation process. The results of the research can serve as a diagnostic tool for the rehabilitation process development.
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Firstly, the way of implementing approximatively the initial rollback of the natural tibiofemoral joint (TFJ) in a total knee replacement (AEQUOS G1 TKR) is discussed. By configuration of the curvatures of the medial and lateral articulating surfaces a cam gear mechanism with positive drive can be installed, which works under force closure of the femoral and tibial surfaces. Briefly the geometric design features in flexion/extension are described and construction-conditioned kinematical and functional properties that arise are discussed. Due to a positive drive of the cam gear under the force closure during the stance phase of gait the articulating surfaces predominantly roll. As a result of rolling, a sliding friction is avoided, thus the resistance to motion is reduced during the stance phase. Secondly, in vivo fluoroscopic measurements of the patella tendon angle during flexion/extension are presented. The patella tendon angle/ knee flexion angle characteristic and the kinematic profile in trend were similar to those observed in the native knee during gait (0°–60°).
W pracy przedstawiono założenia oraz wstępną konstrukcję manipulatora rehabilitacyjnego dla stawu kolanowego. Zaproponowany system będzie wykorzystywany przez chorych w wieku od 6 do 18 lat, u których prowadzone jest wydłużanie kości udowej z zastosowaniem aparatu Ilizarowa. W pracy zamieszczono również wstępne badania, które przeprowadzono przy pomocy systemu Biodex. Polegały one na przeprowadzeniu testów izometrycznych i izotonicznych na pacjentce w wieku 16 lat.
EN
The paper presents the assumptions and design of the knee rehabilitation manipulator. This system will be used by young patient who experenced a lengthening of the femur using the Ilizarov apparatus. Paper presents a preliminary research using the Biodex system. Results consist of isometric and isotonic tests, which was conducted.
The study aims to identify the key points that affect the patello-femoral joint stability and stress distribution. The finite element model of the knee joint is used. The femoral component is rotated along the mechanical axis for 5 degrees both medially and laterally. The stress pressure distribution is analyzed within patello-femoral joint during gait cycle.
CS
Tato práce si klade za cíl urćeni klíćových faktorů ovlivňujících stabilitu patelo-femorálního kloubniho spojení a rozloženi napěti v tomto spojení. Je použit konečně-prvkový model kolenního kloubu. Femorální část náhrady je otáčena kołem mechanické osy o 5 stupňů jak mediálně tak laterálně. Nakonec je provedena analýza rozložení napětí na patelo-femorálním kloubu během chůze.
In the paper the leading wear processes of hip and knee endoprostheses are discussed. Selected results of the tribological tests are given. The influence of the surface treatment on wear of T?6A14V titanium alloy was determined. Additionally, the test results of wear products are given.
The paper points out the growing need for knee joint endoprosthesis. Based on Finite Elements Method, there was designated the reduced stress distribution for two kinds of endoprostheses: sled and total one of Motta-Calle. Because endoprosthesis durability depends on polyethylene insert, the wear research were conducted for the same types of endoprostheses. The researches were carried out on a genuine post (simulator). There was also established how the amount of load cycles influences the changes of polyethylene cristallity. The paper ends up with conclusions on polyethylene wear mechanism.
Presently, CT is one of the most common and accessible methods of human internal structure research. Current programmes for tomographic data processing of data logged from tomography projection allow generation of three-dimensional images of organs. These reconstructions show that they are usually suitable for a precise preparation of surgical procedure operation planning, particularly in the case of joints. In the paper, basic methodology of that kind is shown on the example of a knee joint. The methodology leads to obtaining individual three dimensional models of large human joints. Analysis of tomographic data and creation of the three-dimensional model of the joint was conducted with use of MIMICS.
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The aim of this study was to compare the changes in the power of knee flexors and extensors being the effect of two trainings with different structure of load. The effort depended on performing 40 repetitions in 4 series (group A) as well as 40 repetition in 1 run (group B). The power was estimated based on the value obtained under isokinetic conditions.
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An orthopaedic stabiliser to be used for the treatment of periarticular fractures of the knee joint is presented. The design of the device is documented by experimental research of the knee joint kinematics. Experimental and simulation research suggests the use of a four-bar linkage mechanism. This research has also made it possible to define the range of adjustment to adapt the kinematics of the stabiliser to the individual characteristics of patients. This paper presents the results of the first trials for clinical stabiliser.
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The plane model of human knee, which enables simulation of gait is presented in this paper. As a result of simulation muscle forces, forces in ligaments and reactions between femur and tibia as well as patella and femur were obtained.
The 2D model of human knee is presented in this paper. The anterior and posterior cruciate ligaments, medial and lateral collateral ligaments, patellar ligament and the most important muscles causing movement of lower leg relatively to femur are taken into account. Model enables determination of muscular forces, forces in ligaments, forces between tibia and femur and between patella and femur.
PL
W pracy przedstawiony został dwuwymiarowy model kolana. Uwzględnione zostały więzadła krzyżowe, poboczne, więzadło rzepki i najważniejsze dla ruchu podudzia względem uda mięśnie. Model umożliwia wyznaczenie sił mięśniowych, sił w więzadłach oraz sił reakcji pomiędzy podudziem i udem oraz pomiędzy rzepką i udem.
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