Editorial for “Device for Assessing Knee Joint Dynamics During MR Imaging”

2021 ◽  
Author(s):  
Christopher J. Hanrahan
Keyword(s):  
Mr Imaging ◽  
Knee Joint ◽  
Joint Dynamics

Device for Assessing Knee Joint Dynamics During Magnetic Resonance Imaging

2021 ◽  
Author(s):  
Sandeep P. Jogi ◽  
Rafeek Thaha ◽  
Sriram Rajan ◽  
Vidur Mahajan ◽  
Vasantha K. Venugopal ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Knee Joint ◽  
Resonance Imaging ◽  
Joint Dynamics

Cystic lesions around the knee joint: MR imaging findings.

1994 ◽  
Vol 163 (1) ◽  
pp. 155-161 ◽  
Author(s):  
D L Janzen ◽  
C G Peterfy ◽  
J R Forbes ◽  
P F Tirman ◽  
H K Genant
Keyword(s):  
Mr Imaging ◽  
Knee Joint ◽  
Cystic Lesions ◽  
Imaging Findings

Neuromuscular Reflexes Contribute to Knee Stiffness During Valgus Loading

2005 ◽  
Vol 93 (5) ◽  
pp. 2698-2709 ◽  
Author(s):  
Y. Y. Dhaher ◽  
A. D. Tsoumanis ◽  
T. T. Houle ◽  
W. Z. Rymer
Keyword(s):  
Knee Joint ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Muscle Contractions ◽  
Emg Activity ◽  
Lateral Direction ◽  
Reflex Responses ◽  
Torque Response ◽  
Joint Dynamics ◽  
Periarticular Tissue

We have previously shown that abduction angular perturbations applied to the knee consistently elicit reflex responses in knee joint musculature. Although a stabilizing role for such reflexes is widely proposed, there are as of yet no studies quantifying the contribution of these reflex responses to joint stiffness. In this study, we estimate the mechanical contributions of muscle contractions elicited by mechanical excitation of periarticular tissue receptors to medial-lateral knee joint stiffness. We hypothesize that these reflex muscle contractions will significantly increase knee joint stiffness in the adduction/abduction direction and enhance the overall stability of the knee. To assess medial-lateral joint stiffness, we applied an abducting positional deflection to the fully extended knee using a servomotor and recorded the torque response using a six degree-of-freedom load-cell. EMG activity was also recorded in both relaxed and preactivated quadriceps and hamstrings muscles with surface electrodes. A simple, linear, second-order, delayed model was used to describe the knee joint dynamics in the medial/lateral direction. Our data indicate that excitation of reflexes from periarticular tissue afferents results in a significant increase of the joint’s adduction-abduction stiffness. Similar to muscle stretch reflex action, which is modulated with background activation, these reflexes also show dependence on muscle activation. The potential significance of this reflex stiffness during functional tasks was also discussed. We conclude that reflex activation of knee muscles is sufficient to enhance joint stabilization in the adduction/abduction direction, where knee medial-lateral loading arises frequently during many activities.

Knee Joint Dynamics Predict Patellar Tendinitis in Elite Volleyball Players

1996 ◽  
Vol 24 (5) ◽  
pp. 676-683 ◽  
Author(s):  
David P. Richards ◽  
Stanley V. Ajemian ◽  
J. Preston Wiley ◽  
Ronald F. Zernicke
Keyword(s):  
Knee Joint ◽  
Volleyball Players ◽  
Joint Dynamics

Gadolinium-Dtpa-Enhanced MR Imaging in Asymptomatic Knees

1996 ◽  
Vol 37 (3P2) ◽  
pp. 877-882 ◽  
Author(s):  
T. Boegård ◽  
Å. Johansson ◽  
O. Rudling ◽  
I. Petersson ◽  
K. Forslind ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Knee Joint ◽  
Healthy Subjects ◽  
Knee Joints ◽  
Age Group ◽  
Healthy Individuals ◽  
Middle Aged ◽  
Gadolinium Dtpa ◽  
Contrast Enhanced ◽  
Before And After

Purpose: To evaluate the occurrence and extent of Gd-DTPA-enhanced synovial structures in asymptomatic knee joints of middle-aged healthy individuals. Material and Methods: MR imaging of the knee joint was performed in 10 healthy subjects aged 40–61 years. The study included a sagittal T1-weighted SE sequence before and after i.v. injection of 0.1 mmol Gd-DTPA/kg b.w. Results: Contrast-enhanced synovial structures were found in all knees. The extent of the synovial structures was usually not uniform within the examined joint. In the intercondylar fossa, the thickness of synovial structures was more often pronounced. In the suprapatellar recess, synovial thickness was constant and minimal. Conclusion: The presence and the varying extent and thickness of synovial structures in asymptomatic knees in middle-aged individuals must be considered in the evaluation of early and mild synovitis of the knee joint with Gd-enhanced MR imaging in this age group.

MR imaging of meniscal subluxation in the knee

1997 ◽  
Vol 38 (5) ◽  
pp. 876-879 ◽  
Author(s):  
M. J. Breitenseher ◽  
S. Trattni ◽  
I. Dobrocky ◽  
C. Kukla ◽  
S. Nehrer ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Knee Joint ◽  
Tibial Plateau ◽  
Medial Meniscus ◽  
Lateral Meniscus ◽  
Joint Effusion ◽  
Normal Position ◽  
Rare Finding ◽  
Asymptomatic Volunteers ◽  
The Mean

Purpose: The aim of this study was to establish diagnostic criteria for meniscal subluxation, and to determine whether there was any connection between meniscal subluxation and other common meniscal and knee-joint abnormalities. Material and Methods: The normal position of the meniscal body was assessed in 10 asymptomatic volunteers. MR signs of meniscal subluxation were evaluated retrospectively in 60 symptomatic patients with pain in the knee, impaired mobility, and/or joint swelling who had no clear diagnosis after the evaluation of case history, clinical examination, and radiography. The criterion for subluxation of the meniscus was defined as a distance of ≥3 mm between the peripheral border of the meniscus and the edge of the tibial plateau. Results: In the volunteers, the mean distance from the medial meniscus to the edge of the tibial plateau was 0.07 mm, and that from the lateral meniscus was 0 mm. In 55 symptomatic patients without meniscal subluxation, the mean distance from.the meniscus to the edge of the tibial plateau was 0.27 mm. Five patients (8%) had evidence of meniscal subluxation, 4 in the medial meniscus and one in the lateral meniscus. The most commonly associated knee abnormality was joint effusion in 5 knees and osteoarthritis in 2 knees. Conclusion: Meniscal subluxation was not a rare finding with MR imaging in patients with painful knees. Meniscal subluxation was associated with other knee abnormalities such as joint effusion or osteoarthritis.

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