Background: Ligaments and cartilage contact contribute to the mechanical constraints in the knee joints. However, the precise influence of these structural components on joint movement, especially when the joint constraints are computed using inverse dynamics solutions, is not clear.
Methods: We present a mechanical characterization of the connections between the infinitesimal twist of the tibia and the femur due to restraining forces in the specific tissue components that are engaged and responsible for such motion. These components include the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments and cartilage contact surfaces in the medial and lateral compartments. Their influence on the bony rotation about the instantaneous screw axis is governed by restraining forces along the constraints explored using the principle of reciprocity.
Results: Published kinetic and kinematic joint data (American Society of Mechanical Engineers Grand Challenge Competition to Predict In Vivo Knee Loads) are applied to define knee joint function for verification using an available instrumented knee data set. We found that the line of the ground reaction force (GRF) vector is very close to the axis of the knee joint. It aligns the knee joint with the GRF such that the reaction torques are eliminated. The reaction to the GRF will then be carried by the structural components of the knee instead.
Conclusions: The use of this reciprocal system introduces a new dimension of foot loading to the knee axis alignment. This insight shows that locating knee functional axes is equivalent to the static alignment measurement. This method can be used for the optimal design of braces and orthoses for conservative treatment of knee osteoarthritis.
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http://dx.doi.org/10.7547/1030126 | DOI Listing |
Klin Mikrobiol Infekc Lek
September 2023
Infectious Disease Department, Ceske Budejovice Hospital, Czech Repubic, e-mail:
Corynebacteria, non-spore-forming, gram-positive, aerobic or facultative anaerobic, pleomorphic bacilli, are part of the normal skin, oropharyngeal, and intestinal flora in humans. However, this microorganism can rarely be associated with invasive infections such as bone and joint infections, bacteremia, endocarditis, meningitis, liver and spleen abscesses. We present a case of bacteremic arthritis of a native knee joint caused by non-toxigenic Corynebacterium diphtheriae in a patient with alcoholic liver cirrhosis.
View Article and Find Full Text PDFClin Exp Rheumatol
January 2025
UMass Chan Medical School and UMass Memorial Medical Center, Boston, MA, USA.
Objectives: To assess the efficacy and safety of an intra-articular (IA) CLK/DYRK inhibitor, lorecivivint (LOR), for the treatment of moderate to severe symptomatic knee osteoarthritis (OA).
Methods: This was a Phase 3, 28-week, multicentre, double-blind, placebo-controlled study evaluating the efficacy and safety of a single IA injection of LOR. Patients with ACR-defined knee OA, Kellgren-Lawrence (KL) grades 2-3, and pain Numeric Rating Scale (NRS) ≥4 and ≤8 in the target knee were randomised (1:1) to receive LOR 0.
Clin Exp Rheumatol
January 2025
UMass Chan Medical School and UMass Memorial Medical Center, Boston, MA, USA.
Objectives: To determine the efficacy, safety, and tolerability of intraarticular (IA) lorecivivint (LOR) in the treatment of knee osteoarthritis (OA).
Methods: Patients with American College of Rheumatology criteria-defined knee OA, Kellgren-Lawrence (KL) grades 2-3, and medial Joint Space Width (JSW) by radiograph between 1.5 and 4 mm in the target knee were enrolled in this phase 3, 56-week, multicentre, double-blind, placebo-controlled study.
Introduction Total knee arthroplasty (TKA) is a widely accepted surgical intervention for patients with advanced knee osteoarthritis, aimed at reducing pain and improving functional mobility. Preoperative radiological evaluations, including assessments of joint space narrowing, osteophytes, varus/valgus deformities, and subchondral sclerosis, are essential for planning the surgery and predicting postoperative outcomes. Although extensive research has been conducted internationally, data focusing on populations in Saudi Arabia remain limited.
View Article and Find Full Text PDFOsteoarthr Cartil Open
March 2025
Graduate School of Health Sciences, Morinomiya University of Medical Sciences, Osaka, Japan.
Objective: To investigate whether there is a difference in hardness and hemoglobin concentration changes in the infrapatellar fat pad (IFP) during isometric quadriceps exercise (IQE) in patients with knee osteoarthritis (KOA) between those with and without knee extension limitation.
Design: In this cross-sectional study, data were collected at an orthopedic clinic from March 2022 to April 2023. Among patients diagnosed with KOA, those with knee joint extension range of motion <0° and >0° were defined as the limited group (n = 16) and non-limited group (n = 13), respectively.
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