Purpose of Knee Arthroscopy

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Knee arthroscopy is a minimally invasive surgical procedure to repair or remove damaged structures in the knee joint that can be causing pain and limiting knee range of motion.

During knee arthroscopy, a surgeon uses an arthroscope, a tool about the width of a pencil with a camera and light attached, to view the inside of your knee joint. This allows the surgeon to examine the inside of the knee joint without making a large incision along the outside of the knee, as is done in open surgery.

Knee arthroscopy helps protect the knee joint from the risk of infection due to decreased exposure of the joint to the outside environment, as compared with open surgery. It often results in an improved cosmetic appearance of the knee by reducing the size of the surgical incisions and resulting scar formation.

It also protects the surrounding knee structures, including skin, muscle, tendons, and ligaments from being damaged due to the smaller incisions.

Diagnosis Related to Knee Arthroscopy

Knee arthroscopy is performed for various conditions of the knee to repair or remove structures such as ligaments, cartilage, and bone to help alleviate knee pain and improve functional abilities such as walking, running, squatting, bending, and going up and down stairs. Different procedures performed during knee arthroscopy include:

  • Anterior cruciate ligament (ACL) reconstruction: ACL reconstruction is performed when the ACL becomes torn from injury, typically during twisting motions of the leg when the foot is planted. The ACL runs from the back end of the femur (thigh bone) and attaches to the front end of the tibia (shin bone) and prevents excessive movement of the knee forward.
  • Posterior cruciate ligament (PCL) reconstruction: PCL reconstruction is performed when the PCL becomes torn from injury. PCL injuries are much less common than ACL injuries and typically occur with posterior displacement of the tibia, commonly with motor vehicle accidents when the front of the knee hits the dashboard, or from falling and landing on a bent knee. The PCL runs from the front end of the femur and attaches to the back end of the tibia and prevents excessive movement of the knee backward.
  • Meniscus repair: A meniscus can become damaged from injury to the knee, especially if it involves twisting of the knee joint, or from wear and tear damage from osteoarthritis. The knee joint has a meniscus, a specialized form of cartilage, on both sides between the inner and outer surfaces of the ends of the femur and tibia that provides extra shock absorption in the knee.
  • Meniscectomy: A meniscectomy is a procedure that removes either an entire meniscus (total meniscectomy) or a portion of a damaged meniscus (partial meniscectomy) if the meniscus cannot be repaired.
  • Lateral release: The patella retinaculum is a thick web of connective tissue that attaches the kneecap to surrounding muscles, tendons, ligaments, and bones to hold the kneecap in place. The lateral patellar retinaculum at the outside of the kneecap can become overly tight and pull the kneecap out of alignment, which can cause increased pain and risk of kneecap dislocation, called patellar subluxation. A lateral release involves surgically cutting the lateral patellar retinaculum to loosen the pull on the kneecap.
  • Plica removal: Plica are folds in the synovial membrane lining the knee joint that can become inflamed and irritating, especially when the knee is bent. The synovial membrane holds synovial fluid within the knee that helps to lubricate the cartilage and reduce pressure within the knee joint.
  • Microfracture surgery: A drill is used to create mini fractures in bone to stimulate bone marrow cells, which can help to stimulate the growth of new cartilage in areas of damage. Cartilage allows the bones in the knee joint to glide easily on one another without friction but can become damaged over time due to injury or normal wear and tear associated with aging
  • Autologous chondrocyte implantation: Cartilage cells can be removed arthroscopically, grown in a lab, and re-implanted during another surgery in order to promote new growth of cartilage in areas of damage.
  • Osteochondral autograft transplantation: Cartilage cells can be removed from healthy areas of the knee joint and moved to areas of damage.


To be an eligible candidate for knee arthroscopy, patients usually must try conservative measures first for at least three months unless there is a significant ACL or PCL tear that requires surgery at the earliest time possible. These methods include:

  • Medications: Anti-inflammatory and analgesic (pain-relieving) medications are often prescribed to help manage symptoms.
  • Injections: A healthcare provider may inject cortisone into the knee to locally decrease pain and inflammation.
  • Activity modification: Resting and avoiding painful activities, especially high impact sports and exercises, can reduce inflammation in the knee and promote recovery.
  • Physical therapy: Several weeks of physical therapy can be prescribed to help improve knee strength, range of motion, and functional abilities, as well as administer modalities and manual treatment to help with pain relief. Quadriceps and glute muscle strengthening can help offload pressure at the knee joint to reduce symptoms and improve function.

If you do not experience any improvement in symptoms after several weeks of trying conservative measures, you should follow up with your healthcare provider to discuss your treatment options. If your symptoms continue to significantly impact your daily activities and quality of life, knee arthroscopy may be an option for you to help treat your symptoms.

Always make sure to call your healthcare provider or 911 if you are experiencing a medical emergency.

Tests and Labs

Your healthcare provider will ask about your symptoms and medical history and perform a physical examination to assess your knee joint. Symptoms of increased pain that is acute or chronic in nature, knee instability, decreased range of motion, clicking, locking, and popping are symptoms that may warrant imaging tests to examine the internal structure of the knee joint.

These tests include:

  • X-rays: An X-ray of the knee joint can be used to see if there is malalignment of the knee joint or kneecap or the presence of arthritis by examining the amount of space between the femur and tibia bones. Decreased space indicates degeneration of the cartilage between the bones and is associated with osteoarthritis.
  • Magnetic resonance imaging (MRI): An MRI creates a magnetic field which causes water molecules to align in a certain direction; this is then used to produce an image of the knee. An MRI can be used to determine if there is injury to any of the ligaments of the knee, as well as the menisci and cartilage. There is no radiation involved with an MRI.

A Word From Verywell

Knee arthroscopy may or may not be an appropriate option for you given your age, medical history, and current health status. Always make sure to consult with your practitioner about the possible risks and benefits of undergoing arthroscopic knee surgery. Your healthcare provider will be able to guide you in the right direction if surgery may be necessary or if conservative measures can effectively manage your symptoms.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Academy of Orthopedic Surgeons. Knee arthroscopy.

  2. American Academy of Orthopedic Surgeons. Articular cartilage restoration.

By Kristen Gasnick, PT, DPT
Kristen Gasnick, PT, DPT, is a medical writer and a physical therapist at Holy Name Medical Center in New Jersey.