- Discussion:
- semilunar cartilages are extensions of tibial articulation of knee;
- w/o menisci, tibial articulation is incongruous with the femur;
-
load bearing function:
- menisci distribute forces throughout underlying articular cartilage, thus minimizing point contact;
- menisci bear 40 to 50% of the total load transmitted across joint in extension and 85% of the
compressive load is transmitted through the menisci at 90 deg of flexion;
-
motion characteristics:
- meniscal motion allows maximal congruency during knee flexion and helps to protect the mensici from injury;
- in the study by V. Vedi et al (JBJS Vol 81-B Jan 1999), meniscal movement was studied using a dynamic MRI:
- w/ wt bearing, anterior horn of medial meniscus moved through a mean of 7.1 mm and posterior horn through 3.9 mm, and there was
3.6 mm of mediolateral radial displacement;
- w/ wt bearing, the anterior horn of the lateral meniscus moves 9.5 mm and the posterior horn moves 5.6 mm, and there was 3.7 mm of radial displacement;
- the authors felt that the relative immobility of the posterior horn of the medial mensicus may account for its propensity for injury;
- while secondary stabilizer, menisci do impart some stability to normal knee and more important to the ligament deficient knee;
- each is attached at its periphery to capsular ligament on medial or lateral side of joint & at its horns to interarticular area of tibia;
- connecting menisci anteriorly is the transverse ligament.
- menisci help compensate for incongruence of the bones, and they appear to be involved in rotation by moving on the tibia;
- as result of sufficient stress (usually rotary in wt-bearing, flexed knee), either meniscus may be torn w/in itself or from its peripheral attachment;
-
microscopic features:
-
vascular anatomy:
-
anatomy:
-
medial meniscus
-
bucket handle meniscus tear:
-
posterior horn tears of medial meniscus:
-
lateral meniscus
-
discoid meniscus
- MRI Features:
- Management of Meniscal Tears
Newest Knowledge of the Knee Joint Meniscus--Symposium: Pathology of the Meniscus.
The knee joint meniscus. A fibrocartilage of some distinction.
A long-term follow-up study of total meniscectomy in children.
Precision in the diagnosis of meniscal lesions: a comparison of clinical evaluation, arthrography, and arthroscopy.
Lesions of the menisci. Autopsy incidence in adults less than fifty-five years old.
Partial versus total meniscectomy. A prospective, randomised study with long-term follow-up.
The innervation of the human meniscus.
Arthroscopic treatment of meniscal cysts.
Meniscal injury associated with femoral shaft fractures. An arthroscopic evaluation of incidence.
Magnetic resonance imaging of a symptomatic meniscal ossicle.
Meniscal Transplantation in Symptomatic Patients Less Than Fifty Years Old.
Transplantation of Viable Meniscal Allograft Survivorship Analysis and Clinical Outcome of One Hundred Cases.
