Medial Meniscus: Difference between revisions
Aarti Sareen (talk | contribs) No edit summary |
Aarti Sareen (talk | contribs) No edit summary |
||
| Line 5: | Line 5: | ||
== Anatomy and attachment == | == Anatomy and attachment == | ||
The medial meniscus is approximately 1.4 in (3.5cm) in length. The anterior horn of the medial meniscus is attached to the anterior surface of the tibia well off the tibial plateau. The anterior fibers of the anterior cruciate attachment merge with the transverse ligament, which connects the anterior horns of the medial. The posterior horn of the medial meniscus is firmly attached to the posterior aspect of the periphery to the joint capsule. At its midpoint, the meniscus is firmly attached to the femur and tibia through a condensation in the joint capsule known as the deep medial ligament. The medial meniscus has no direct attachment to any muscle, but indirect capsule connections to the semimembranosus may provide some retraction of the posterior horn. <br>Medial menisci are C shaped wedge fibrocartilagenous structure located between condyle of femur and tibia. It is somewhat more in C shape as compared to lateral menisci as it is medial meniscus are clear of the plateau anteriorly and posteriorly. Anteriorly, it is also attached to lateral menisci by transverse ligament and patella either directly or by patellomeniscal ligaments which are anterior capsular thickenings<ref>Tuxoe JI, Teir M, Winge S, et al.: The medial patellofemoral ligament: A dissection study. Knee Surg Sports Traumatol Arthrosc 10:138–140, 2002.</ref>. Its anterior portion is much narrower than the posterior portion and the narrower portion is less prone to injury also.<br>'''VASCULAR SUPPLY:''' | |||
The vascular supply of the menisci originates predominately from the inferior and superior lateral and medial genicular arteries. During the first year of life the meniscus contains blood vessels throughout its body but when the weight bearing starts the vascularity and the circulatory network diminish and only 25-33% area remain vascular by the capillaries of the capsule and synovial membrane<ref name="gray">Gray JC: Neural and vascular anatomy of the menisci of the human knee. J Orthop Sports Phys Ther 29:23–30, 1999.</ref>. The vascularity diminishes so much that in 4th decade of life only the periphery is vascular whereas the center of the menisci is avascular. The center portion is completely dependent upon the synovial fluid diffusion for nutrition<ref>McCarty EC, Marx RG, DeHaven KE: Meniscus repair: Considerations in treatment and update of clinical results. Clin Orthop 402:122–134, 2002.</ref>. The central avascular portion of menisci either does not heal completely or heal at all after injury<ref name="gray" />. | |||
'''NERVE SUPPLY:'''<br>The horns of the menisci and the peripheral vascularized portion of the meniscal bodies are well innervated with free nerve endings (nociceptors) and three different mechanoreceptors (Ruffini corpuscles, pacinian corpuscles, and Golgi tendon organs)<ref name="gray" /><ref>Zimny ML, Albright DJ, Dabezies E: Mechanoreceptors in the human medial meniscus. Acta Anat (Basel) 133:35–40, 1988.</ref><ref>Mine T, Kimura M, Sakka A, et al.: Innervation of nociceptors in the menisci of the knee joint: An immunohistochemical study. Arch Orthop Trauma Surg 120:201–204, 2000.</ref>.<br><br> | |||
== Nutrition and innervation == | == Nutrition and innervation == | ||
Revision as of 19:57, 30 September 2013
Introduction[edit | edit source]
The word menisci are derived from the Greek work meniskos, which means "crescent"[1].At knee joint the menisci plays a major role in congurency of the joint. Menisci forms the concavity in which the femoral condyles sits. Menisci rests between the thigh bone femur and the tibia and there are two knee joint ligaments. They are a type of cartilage in the joint. The rubbery texture of the menisci is due to their fibrocartilagenous structure. Their shape is maintained by the collagens within them. One meniscus is on the inner side of your knee--the medial meniscus. The other meniscus is on the outer side of your knee--the lateral meniscus.
Anatomy and attachment[edit | edit source]
The medial meniscus is approximately 1.4 in (3.5cm) in length. The anterior horn of the medial meniscus is attached to the anterior surface of the tibia well off the tibial plateau. The anterior fibers of the anterior cruciate attachment merge with the transverse ligament, which connects the anterior horns of the medial. The posterior horn of the medial meniscus is firmly attached to the posterior aspect of the periphery to the joint capsule. At its midpoint, the meniscus is firmly attached to the femur and tibia through a condensation in the joint capsule known as the deep medial ligament. The medial meniscus has no direct attachment to any muscle, but indirect capsule connections to the semimembranosus may provide some retraction of the posterior horn.
Medial menisci are C shaped wedge fibrocartilagenous structure located between condyle of femur and tibia. It is somewhat more in C shape as compared to lateral menisci as it is medial meniscus are clear of the plateau anteriorly and posteriorly. Anteriorly, it is also attached to lateral menisci by transverse ligament and patella either directly or by patellomeniscal ligaments which are anterior capsular thickenings[2]. Its anterior portion is much narrower than the posterior portion and the narrower portion is less prone to injury also.
VASCULAR SUPPLY:
The vascular supply of the menisci originates predominately from the inferior and superior lateral and medial genicular arteries. During the first year of life the meniscus contains blood vessels throughout its body but when the weight bearing starts the vascularity and the circulatory network diminish and only 25-33% area remain vascular by the capillaries of the capsule and synovial membrane[3]. The vascularity diminishes so much that in 4th decade of life only the periphery is vascular whereas the center of the menisci is avascular. The center portion is completely dependent upon the synovial fluid diffusion for nutrition[4]. The central avascular portion of menisci either does not heal completely or heal at all after injury[3].
NERVE SUPPLY:
The horns of the menisci and the peripheral vascularized portion of the meniscal bodies are well innervated with free nerve endings (nociceptors) and three different mechanoreceptors (Ruffini corpuscles, pacinian corpuscles, and Golgi tendon organs)[3][5][6].
Nutrition and innervation[edit | edit source]
Role[edit | edit source]
Injury[edit | edit source]
Special tests[edit | edit source]
References[edit | edit source]
- ↑ μηνίσκος, "small moon", is diminutive of μήνη, "moon", from the root ma-, "measure", which reflects the fact the time was measured according to the phases of the moon. The word was also used for curved things in general, such as a necklace or a line of battle. (Lexicon of Orthopaedic Etymology, p 199)
- ↑ Tuxoe JI, Teir M, Winge S, et al.: The medial patellofemoral ligament: A dissection study. Knee Surg Sports Traumatol Arthrosc 10:138–140, 2002.
- ↑ 3.0 3.1 3.2 Gray JC: Neural and vascular anatomy of the menisci of the human knee. J Orthop Sports Phys Ther 29:23–30, 1999.
- ↑ McCarty EC, Marx RG, DeHaven KE: Meniscus repair: Considerations in treatment and update of clinical results. Clin Orthop 402:122–134, 2002.
- ↑ Zimny ML, Albright DJ, Dabezies E: Mechanoreceptors in the human medial meniscus. Acta Anat (Basel) 133:35–40, 1988.
- ↑ Mine T, Kimura M, Sakka A, et al.: Innervation of nociceptors in the menisci of the knee joint: An immunohistochemical study. Arch Orthop Trauma Surg 120:201–204, 2000.
