What is a Knee Arthroscopy?
Knee arthroscopy is a surgical procedure that places a small camera and small tools into the knee joint using very small incisions, to treat injuries inside the knee joint.
Knee arthroscopy is a procedure in which the surgeon examines the inside of your knee joint with a camera instrument called an arthroscope. An arthroscope is a metal tube with a camera and light at its end that projects an image of the inside of your knee onto a television monitor. The arthroscope is about the diameter of a pencil.
When performing an arthroscopy, the surgeon will insert the arthroscope into the knee joint through a small ¼ inch incision, and through a second incision, small tools can be inserted to trim or fix the damage inside the knee.
During the procedure, fluid is injected into the knee to expand the joint so that the structures and cartilage can be seen. The surgeon will examine the entire inside of the knee to find any damage and this can be photographed to show you later what was wrong.
During the procedure, the torn cartilage can be repaired or trimmed, frayed or torn cartilage can be shaved down with special small shaving tools, debris can be removed with suction shavers and other tools can be used to seal the tissues. The arthroscope and tools are then removed, and the incisions are closed with stitches.
What are the main indications that someone may require knee arthroscopy?
The main indications for requiring a knee arthroscopy include:
- Torn Meniscus
- Articular Cartilage Flap Tears
- Loose Bodies
- ACL Tears
- Arthritic isolated lesion
- Osteochondral Defects
- Patella Clunk Syndrome (scar tissue)
- Scar Tissue pain after Partial Knee Replacement
- Patellar Dislocation with Loose Body
- Patella Mal-tracking
Arthroscopic Treatment for Knee Conditions
The knee arthroscopy procedure treats many different knee conditions and issues. Here are a few of the most common:
A meniscus tear means that the fibrocartilaginous structure that protects the knee joints articular cartilage and acts as a shock absorber called the meniscus, is torn. Meniscus tears can occur in the medial or lateral meniscus. Meniscus tears can also occur in the front, the middle or the back portion of the meniscus. These are called the anterior horn, body, and posterior horn, respectively. Click to learn more about torn meniscus.
Articular Cartilage Flap Tear Debridement
Articular Cartilage Flap Tears that are causing pain, catching, locking, or loss of motion can also be trimmed back to a smooth edge using the same tools to trim a meniscus tear. These flaps can occur from an acute injury or from degenerative arthritis.
Discoid Lateral Meniscus Tear
A variant of the lateral meniscus is called a discoid lateral meniscus. Sometimes there can be a tear of this enlarged meniscal tissue that is painful, which requires a partial lateral meniscectomy.
Loose Bodies Removal
Sometimes pieces of cartilage can break free from the surface of the knee joint and become loose, moving around as the knee bends. These loose bodies can cause sudden pain and reduce or block motion.
These “loose bodies” can be removed from the knee joint arthroscopically.
Patella Clunk Syndrome (Scar Tissue)
In rare cases of total knee replacement, scar tissue develops that catches on the implants during knee bending that makes a clunking sound. During arthroscopic surgery, you can use a shaver and a coblation tool to remove the scar tissue and stop the catching, clunking and crunching that can be present.
ACL Tear Reconstruction
When the Anterior Cruciate ligament gets torn, this can be reconstructed during an arthroscopic procedure where a new ligamentous structure is installed in place of the old torn ligament.
Microfracture for Osteochondral Defects
In cases where there is a loss of cartilage over an isolated area of the joint surface, a technique to drill small channels into the bone to reach the blood supply can cause a healing reaction and bring cells to the surface to make a repair layer of cartilage on bone.
Lateral Release for Patellofemoral Mal-Tracking
Some patients have a condition where the knee cap (patella) is not staying in the center of the knee as it bends, and it tends to drift off to the side (laterally). In some cases, this causes pain. In these cases, one option is to release the tissues on the lateral side of the knee cap arthroscopically from the inside to allow the knee cap to track back in the center. This is called an arthroscopic lateral release.
When the lining of the knee joint (Synovium) is inflamed, the arthroscopic tools can be used to trim out and cauterize the hypertrophied inflamed tissue that causes pain and swelling.
What risks are associated with knee arthroscopy?
- Most pain but not always all pain is reduced from this procedure depending on individual joint conditions.
- Continued pain may be present after a knee arthroscopy depending on the condition of the inside of your knee.
- The remaining meniscus tissue can re-tear in the future requiring further arthroscopic or surgical intervention.
There is a small risk of infection.
- The is a risk of moderate bleeding into the knee joint after surgery from the tiny vessels that can cause significant swelling, reduced motion, and pain.
- Although all knees bleed a little in the joint after surgery, if the swelling is significant, aspirating (draining the blood with a needle) the blood in the office can significantly improve the acute pain and swelling allowing healing to then proceed more comfortably.
- The small incisions can remain tender after surgery for several months preventing one from kneeling or putting pressure on these areas.
- There is a small risk that the blood vessels and nerves around the knee may be injured, causing numbness, or weakness in the leg below the knee.
- There are risks associated with general anesthesia and these should be discussed with your anesthesiologist.
- There is a risk of deep vein thrombosis, a condition in which a blood clot forms within a deep vein from having surgery on a lower extremity.
What is the post-operative care after a knee arthroscopy procedure?
- You will be discharged approximately one hour after your procedure when you are stable and have recovered from your anesthesia with the recovery room nurses.
- You will go home and should keep your leg elevated.
- Elevate your leg so that your ankle is higher than your knee, and your knee is higher than your hip to keep the swelling to a minimum.
- Take it easy for at least the next 2 to 3 days to allow the small vessels to seal and minimize the initial swelling into the knee joint.
- Do not take part in any strenuous activities until your doctor feels that you are ready.
- Use crutches or a cane for 1 to 2 days, or until you can walk nearly normally.
- Put ice on your knee for 20 to 30 minutes 3 to 4 times per day to reduce swelling and pain. You may do this for several weeks to help the symptoms.
- Bending your knee is allowed but do not force the motion until the swelling has resolved.
- You may remove your gauze dressing after 48 hours and just cover the incisions with Band-Aids.
- You may shower with the clear dressing on from the hospital. Remove and replace Ace wrap before and after showering for 48-72 hours to apply gentle compression and reduce swelling. Do not tighten the wrap excessively, or the lower leg will swell from constricting the return blood flow from the foot.
- If the cartilage is repaired and not trimmed, your physician may want you to use crutches longer, and to not put weight on your leg.
- Follow-up with your surgeon at the office in 6-10 days or as instructed.
- Physical therapy can be beneficial for some, for 3-6 weeks.
- Return to light duty work can occur in a few days to a couple weeks.