Meniscus tear

Meniscus tear

MSNS1 EXAM 1

MSNS1 EXAM 1

Development of the axial skeleton
Development of the limbs
Development of the muscular system
Bone histology
Cartilage histology
Skeletal muscle histology
Skeletal system anatomy and physiology
Bone remodeling and repair
Cartilage structure and growth
Fibrous, cartilage, and synovial joints
Muscular system anatomy and physiology
Brachial plexus
Neuromuscular junction and motor unit
Sliding filament model of muscle contraction
Slow twitch and fast twitch muscle fibers
Muscle contraction
Muscle spindles and golgi tendon organs
Rotator cuff tear
Dislocated shoulder
Radial head subluxation (Nursemaid elbow)
Winged scapula
Thoracic outlet syndrome
Carpal tunnel syndrome
Ulnar claw
Erb-Duchenne palsy
Klumpke paralysis
Iliotibial band syndrome
Unhappy triad
Anterior cruciate ligament injury
Patellar tendon rupture
Meniscus tear
Patellofemoral pain syndrome
Sprained ankle
Achilles tendon rupture
Spondylolysis
Spondylolisthesis
Degenerative disc disease
Spinal disc herniation
Sciatica
Compartment syndrome
Rhabdomyolysis
Osteogenesis imperfecta
Craniosynostosis
Pectus excavatum
Arthrogryposis
Genu valgum
Genu varum
Pigeon toe
Flat feet
Club foot
Cleidocranial dysplasia
Achondroplasia
Osteomyelitis
Bone tumors
Osteochondroma
Chondrosarcoma
Osteoporosis
Osteomalacia and rickets
Osteopetrosis
Paget disease of bone
Osteosclerosis
Lordosis, kyphosis, and scoliosis
Osteoarthritis
Spondylosis
Spinal stenosis
Rheumatoid arthritis
Juvenile idiopathic arthritis
Gout
Calcium pyrophosphate deposition disease (pseudogout)
Psoriatic arthritis
Ankylosing spondylitis
Reactive arthritis
Spondylitis
Septic arthritis
Bursitis
Baker cyst
Muscular dystrophy
Polymyositis
Dermatomyositis
Inclusion body myopathy
Polymyalgia rheumatica
Fibromyalgia
Rhabdomyosarcoma
Myasthenia gravis
Lambert-Eaton myasthenic syndrome
Gout and pseudogout: Pathology review
Bone tumors: Pathology review
Muscular dystrophies and mitochondrial myopathies: Pathology review
Bone disorders: Pathology review
Acetaminophen (Paracetamol)
Non-steroidal anti-inflammatory drugs
Glucocorticoids
Antigout medications
Osteoporosis medications

Transcript

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The menisci are crescent-shaped fibrocartilage cushions found in the knee joint.

Normally, there’s the medial and lateral menisci between the femur and the tibia.

So, a meniscus tear, more commonly known as torn knee cartilage, is when one of the menisci of the knee is torn.

This usually occurs due to trauma during contact sports.

The knee is a complex joint, actually it’s a combination of three joints.

These are the femoropatellar joint, between the femur and patella, and the two tibiofemoral joints which are formed by the bony prominences, also called the condyles of the tibia and the femur.

Between the femoral and tibial condyles, there’re the medial and lateral menisci.

The menisci act to absorb compressive force, which can reach up to three times the body weight while walking!

In addition, the menisci have a cup-shaped surface which provides a deeper place for the condyles to fit in improving joint’s stability.

Next, the knee joint is supported by a number of ligaments.

So, within the joint space, there's the anterior cruciate ligament, or ACL, which runs from the anterior middle edge of the tibia to the lateral condyle of the femur, and the posterior cruciate ligament, or PCL, that runs from the middle posterior edge of the tibia to the medial condyle of the femur.

Now, outside the joint space, we’ve got one collateral ligament between the femur and the tibia on each side of the joint, which are the lateral collateral ligament, or LCL, and the medial collateral ligament, or MCL.

The MCL is firmly attached to the medial meniscus, which makes it less mobile compared to the lateral meniscus.

A meniscus tear can occur when the meniscus is violently compressed, called an acute tear, which usually occurs in young athletes.

Acute tears typically occur when the knee is bent and at the same time excessively twisted, like when you’re playing basketball and then you suddenly change direction, trying to crossover another player.

Acute meniscus tears can also occur as a part of the unhappy triad injury.

This is where a lateral force to the knee, like when the knee is hit by a hockey puck, causes tears in the ACL, MCL and one of the menisci.

Now, regarding which of the menisci, it’s worth mentioning that even though the classic “unhappy triad” consists of the ACL, MCL and medial meniscus tears, the lateral meniscus is more commonly injured than the medial.

This is because when the knee is affected by a blow from the lateral side, the lateral meniscus gets compressed between the tibia and the femur, leading to injury.

In contrast to an acute tear, there are also chronic tears, which usually occur in older people.

This is because the wear and tear of the menisci make them more susceptible to tears with minimal force, or any noticeable trauma.

An elderly person might tear their meniscus from simply getting up from a chair.

Alright, let’s talk about symptoms.

Key Takeaways

Meniscus tear is when one or both of the menisci of the knee joint are torn. Acute tears usually occur in athletes during contact sports, when the menisci are violently compressed. Chronic tears can also occur, often in older people due to wear and tear changes of menisci. Symptoms include pain, swelling, and stiffness, and the diagnosis is mainly based on clinical symptoms, physical exam with an MRI for confirmation. Treatment can be conservative, or by open or arthroscopic surgery.

Sources

  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine" McGraw Hill Education/ Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Meniscal Injuries in the Young, Athletically Active Patient" The Physician and Sportsmedicine (2011)
  6. "Risk Factors for Meniscal Tears: A Systematic Review Including Meta-analysis" Journal of Orthopaedic & Sports Physical Therapy (2013)
  7. "The menisci: basic science and advances in treatment" British Journal of Sports Medicine (2000)