The menisci are fibrocartilaginous wedge-shaped structures between the distal femur and proximal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy that stabilize and dissipate weight-bearing forces at the knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy. A meniscus tear is an injury to the meniscus caused by rotational or shearing forces Shearing forces Vascular Resistance, Flow, and Mean Arterial Pressure across the tibiofemoral joint Tibiofemoral joint Knee Joint: Anatomy. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor in a young patient with a traumatic tear includes a history of a twisting or rotational injury followed by pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways at the joint line with a small effusion. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor in an older patient includes weight-bearing pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways at the joint line that mimics and accompanies progressive pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways due to the degenerative changes Degenerative Changes Spinal Stenosis of osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis. Mechanical complaints (e.g., joint locking, catching, or clicking) are also common. Diagnosis can be challenging clinically and is often confirmed by diagnostic imaging or by direct visualization ( arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries). Management can be conservative or surgical, depending on the individual situation.
Last updated: 10 Aug, 2021
Menisci of the knee
Image by Lecturio. License: CC BY-NC-SA 4.0There are several types of tear patterns in meniscal tears:
Clinical anatomy:
Traumatic mechanisms for tears:
Diagnosis is usually suspected with a thorough history and physical examination, and often confirmed with diagnostic imaging (e.g., MRI) or by direct visualization (e.g., arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries).
X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests demonstrating medial joint space narrowing
Image: “Postoperative radiography at 3 month follow-up” by Steinmetz S, Bonnomet F, Rahme M, Adam P, Ehlinger M. License: CC BY 4.0Ultrasound:
MRI:
MRI of the right knee revealing intra-articular and bucket-handle medial meniscus tear with the displaced fragment located in the intercondylar notch
Image: “ Coronal Coronal Computed Tomography (CT) MRI of the right knee” by Ahmed Ali R, McKay S. License: CC BY 3.0MRI of the knee showing horizontal tear (white arrow) at the posterior horn Posterior horn One of three central columns of the spinal cord. It is composed of gray matter spinal laminae i-vi. Brown-Séquard Syndrome of medial meniscus
Image: “A sagittal Sagittal Computed Tomography (CT) T2-weighted MRI shows horizontal tear” by Journal of Orthopaedic Surgery and Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest. License: CC BY 4.0Arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries:
Arthroscopy
Arthroscopy
Endoscopic examination, therapy and surgery of the joint.
Knee Ligament Injuries with arthroscopic meniscus repair:
A: discoid lateral meniscus with longitudinal tear
B: discoid lateral meniscus following partial resection
Management of meniscal tears is dependent on the type of tear, age of the patient, occupation of the patient, associated mechanical symptoms, and other associated injuries (e.g., ACL tear ACL tear Knee Pain).
Conservative management indicated as initial treatment in degenerative tears in older patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship or prior to arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries in younger patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship:
Arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries surgical positioning
Image: “The position for viewing the medial meniscus in right knee” by Gupta Y, Mahara DP, Lamichhane AP. License: CC BY 4.0Medial meniscus fold as seen through anterolateral portal
Image: “Appearance of medial meniscus flounce” by Gupta Y, Mahara DP, Lamichhane AP. License: CC BY 4.0Knee arthroscopy Arthroscopy Endoscopic examination, therapy and surgery of the joint. Knee Ligament Injuries with meniscectomy
Image by Lecturio.Long-term outcomes depend on: