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At least 19 recordsLinked to original sources
PubMed1975

Variations in collagen, non-collagenous proteins, and hexosamine in menisci derived from osteoarthritic and rheumatoid arthritic knee joints.

Knee joint menisci from osteoarthritic and rheumatoid knees were analyzed for nitrogen, collagen, non-collagenous proteins (NCP) and hexamine content. Degenerate areas were analyzed separately. The degenerative areas were significantly lower (P less than 0.005) in collagen but NCP and hexosamines were elevated relative to control tissue. The rheumatoid menisci revealed a reduced level of collagen and hexosamine in areas of localized degeneration. However, the collagen and hexosamine content of the remaining tissue was also diminished (P less than 0.025) relative to normal tissue of the same. age.

Adult↗
PubMed2005

Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque.

In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help determine the effect of muscle strength training, and so on.

Adult↗
PubMed2003

[Reduced pain from osteoarthritis in hip joint or knee joint during treatment with calcium ascorbate. A randomized, placebo-controlled cross-over trial in general practice].

INTRODUCTION: Although vitamin C is essential for the formation of collagen and proteoglycan and has been shown to minimise surgically induced arthritis in guinea pigs, no controlled trial has examined its effect on human osteoarthritis. MATERIAL AND METHODS: The trial was a multicenter, double-blind, randomised, placebo-controlled, crossover-trial performed by ten general practitioners. The Declaration of Helsinki and the European guidelines for good clinical practice were strictly followed. One hundred and thirty-three patients with radiographically verified symptomatic osteoarthritis of the hip joints and/or the knee joints were treated with one gram of calcium ascorbate or identically looking placebo tablets. The calcium ascorbate tablets and the placebo tablets should be swallowed daily for 14 +/- 3 days respectively, separated by 7 +/- 3 days wash out. The main outcome measure was difference on the 100 mm visual analog scale (VAS) score for pain in a preselected joint. The secondary outcomes were Lequesne score for function and patient preference. RESULTS: Calculated on an intention-to-treat principle, calcium ascorbate reduced pain significantly compared to placebo (p = 0.0078 by analysis of variance between groups (ANOVA) for difference in VAS, mean difference 4.6 mm (95% CI 1.2-8.0). Similar superiority was found for Lequesne index (p = 0.036, difference 0.56 (95% CI 0.04-1.08) and for patient preference (p = 0.012). DISCUSSION: The demonstrated effect is less than half as pronounced as commonly reported for NSAID etc. If the finding can be reproduced with a smaller, acceptable intake of vitamin C this would be of importance considering the large prevalence of osteoarthrosis.

Adult↗
PubMed1988

[Sprains and dislocations of large joints--the knee joint].

Recent "distorsion" injuries of the knee joint should be diagnosed with great precision. While injuries that do not produce instability should be treated conservatively, early surgical repair is the treatment of choice for the unstable knee. If a reliable evaluation is not possible, a general anesthetic is required; arthroscopy is reserved for special questions. Dislocation of the knee is a true surgical emergency. The vascular insult caused by the severe injury requires immediate attention.

Arthroscopy↗
PubMed1976

Stabilizing mechanisms of the loaded and unloaded knee joint.

Knee specimens were placed in an apparatus which imposed cyclic anterior-posterior or rotatory forces, with various compressive loads applied to the joint. Force-displacement graphs or torque-rotation graphs were automatically plotted, giving the laxity under various conditions. The ligaments, capsule, and menisci provided joint stability under no-load conditions. However, under compressive loads, the conformity of the condylar surfaces was an important factor in stabilizing the knee. The mechanism proposed was the uphill movement of the femur as the femur and the tibia were displaced or twisted relative to one another.

Adult↗
PubMed1983

[New method of describing the motion of the knee joint].

Knee motion in the full flexion range was measured for fourteen specimens under moderate load, and for eight normal volunteers while descending a step. Measurements showed that the posterior femoral condyles could be accurately modelled as parts of spheres. The line joining the centers of the spheres was defined as the femoral axis and joint motion was described by motion of this axis relative to axes defined on the tibial surface. From 0 to 120 degrees of flexion, the lateral center moved posteriorly by seventeen millimeters, the medical center moved forward by two millimeters, external rotation was 20 degrees, and varus-valgus rotation was 4 degrees. Specimens and volunteers gave similar results. The method was simple and accurate and has several potential applications.

Humans↗
PubMed1980

[Problems of therapy control in arthroses and suggestion of a method for the non-invasive identification of changes in joint morphology (knee joint) (author's transl)].

The article explains the fundamental problems in therapeutic studies of the primary and secondary processes in arthrosis. Many drugs are on the market for treating the secondary phenomena; however, such phenomena can often be assessed only on the basis of "soft" action criteria (verbal information given by the patients). Biochemical examinations of the synovial fluid and methods to assess joint morphology, are particularly suitable for evaluating the primary changes taking place in the joint cartilage. An assessment of the "joint noises" is known in literature as a non-invasive method. An improved method of recording and evaluating these joint noises is suggested. It is characterized by the following features: - registration of signals with defined joint load - classification of the noise phenomena with reference to the joint position, i.e. to joint areas - by separation of the signal into movement cycles elimination of artificial noise producers - evaluation of those signal periods only which are disease-specific. The article shows examples by quoting signals with the respective frequencies for healthy and diseased persons, and explains the suitability of the method in therapy control by describing two examples of surgical treatment.

Humans↗
PubMed1980

Load-bearing mode of the knee joint: physical behavior of the knee joint with or without menisci.

The load-bearing mode of the knee joint and the load-carrying capacity of the menisci were investigated by a load-deflection and load-contact study using stresses of as much as 3 times body weight on 14 freshly amputated knee specimens. A flection angle of 0 degrees was used. The average deflection and the average size of the contact area of the intact knees were 1.04 x 10(-1) cm and 14.1 cm2 respectively when the knees were loaded to 1,500 N. The elastic modulus of the entire joint was 2.7 x 10(2) MPa over the load of 1,500 N. At first, the knee joint was not congruous at a low load under about 500 N; the joint contacts both menisci in conjunction with some part of the exposed cartilage. However, the joint became markedly congruous at higher loads, around 1,000 N. The joint was in contact with the menisci and the exposed cartilage, and as more load was applied, the areas of contact widened to the peripheral areas of both the compartments. After menisci were removed, the deflection increased. The size of the contact areas decreased significantly by a third to a half. Consequently, the average stress increased 2 to 3 times that of the intact knee. The elastic modulus was increased over 2 fold after menisci were removed. The results of the energy study indicate that the menisci gave more elastic stability to the joint. After the menisci were removed, more energy was dissipated during cyclic loading. Thus, the menisci provide surface compliance and serve to transmit stresses across the wider areas to the periphery, and, therefore, help to avoid stress concentration both in the articular cartilage and in the subchondral bone, especially under high loads over 1,000 N.

Adult↗
PubMed1976

[Knee joint prosthesis with the geomedic knee joint (author's transl)].

Thirty-one cases of plastic knee joint operations were reported. Twenty-one patients were treated with the geomedic knee. The advantage of this joint is that only a small amount of bone must be sacraficed. The range of movement is better than that with a complete knee prosthesis with axis.

Aged↗