Knee Arthroscopy Surgery
According to the American Orthopedic Society of Sports Medicine, over four million knee arthroscopies are performed each year globally. An arthroscope is a very small camera instrument comparable to the size of a pencil. Arthroscopy is a standard surgical procedure, during which an orthopedic surgeon uses this small camera instrument to view clearly the inside of a joint. When performed on the knee, arthroscopy helps doctors see the structures of the knee with extreme accuracy, by inserting the arthroscope into the knee joint through small incisions (portals). The arthroscope sends images of the inside of the knee joint onto a television monitor, which allows the surgeon to feel, repair, and remove damaged tissue. To accomplish this, small surgical tools are inserted through other small incisions around the knee.
What an Arthroscope can See Inside of the Knee
With an arthroscope (small camera), an orthopedic surgeon can see many structures inside of the knee. The knee is essentially a hinge assembled by the ends of the thigh bone (femur) and the leg bone (tibia). The knee cap (patella) is over the front of the knee joint and touches the femur when the knee bends. The exterior portion of the femur, tibia, and patella are covered with smooth cartilage (articular cartilage), which enables them to glide over each other when the knee bends and straightens. An arthroscope can see these structures and this articular cartilage, which is smooth, white, and about three to four millimeters thick.
An arthroscope also makes visible a second type of cartilage in the knee, called the meniscus. The meniscus is a tough and fibrous type of cartilage that is located between the ends of the tibia and the femur, and is fastened to the lining of the joint. The main function of the menisci is shock absorption between the ends of the bones, to cushion the surface articular cartilage. There are two different meniscal cartilages in the knee. Both are relatively C-shaped: one on the inner half of the knee (medial meniscus), and one on the outer half of the knee (lateral meniscus).
An arthroscope can also make visible the ligaments within the knee, specifically the large anterior and posterior cruciate ligaments.
Why Have Knee Arthroscopy Surgery?
Knee arthroscopy surgery may be performed to aid in the diagnosis and treatment of knee problems. Technical advancements have resulted in very high definition monitors and high-resolution cameras, along with other developments that allow knee arthroscopy to be a very successful tool for treating knee problems. An orthopedic surgeon may recommend knee arthroscopy surgery to diagnose, locate, repair, and extract damaged tissue.
Arthroscopy for the knee is most usually performed for:
- Repair or removal of torn meniscal cartilage
- Reconstruction of a torn anterior cruciate ligament
- Clipping of torn pieces of articular cartilage
- Removal of inflamed synovial tissue
- Removal of loose fragments of bone or cartilage
What is a cartilage tear?
A cartilage tear typically refers to a tear of the meniscus, which can occur several ways. Tears can ensue from an abrupt twisting-type injury or can develop gradually with age. The tear can occur in either the outer thick part or inner thin part of the meniscus. Some tears damage only a small part of the meniscus, while others injure almost the entire meniscus. Tears in the meniscus can lead to symptoms from parts of the torn fragments getting stuck or jerked between the bones as the knee moves. This may cause locking, snapping or popping, pain, and swelling. Not all meniscus tears lead to problems, but an arthroscope can be performed to cut out the torn piece. Only the piece that is torn will be removed.
Can the meniscus be repaired?
The potential for a meniscus to heal after an injury depends mainly on its blood supply. The outer thick portion of the meniscus receives a steady blood supply, but the inner thin portion of the meniscus receives a poor supply. Therefore, tears on the outer part of the meniscus are more compliant with successful repair than the inner part, which is typically removed rather than repaired. Chronic or older tears also typically have poor repair success rates, so this tissue is usually excised, as well.
Knee Arthroscopy for Arthritis
Knee arthroscopy surgery can also be used to relieve pain from arthritis in some cases. While the results are somewhat unpredictable, arthroscopic surgery often improves arthritic pain for, sometimes years. Knee arthroscopy surgery may be a reasonable treatment for arthritis patients in whom other treatments such as injections and medications have failed to supply any considerable relief.
Risks and Complications of Knee Arthroscopy Surgery
There are possible risks and complications associated with knee arthroscopic surgery, as with any surgery. Potential post surgery problems with knee arthroscopy include:
- Accumulation of blood in the knee
- Blood clots
A patient should immediately contact their orthopedic surgeon if they experience any of the following symptoms after knee arthroscopy surgery:
- Significant swelling of the knee
- Increasing pain in the calf muscle
- Ongoing redness and warmth around the knee
- Ongoing or increased pain
What to Expect Before Knee Arthroscopy Surgery
Before knee arthroscopy surgery, the patient will usually undergo a complete physical examination to evaluate a patient’s health and pinpoint any problems that could interfere with the surgery.
The patient should inform their doctor of any medications or supplements they are taking before surgery, and the doctor will inform the patient of what medications to stop taking prior to surgery.
The surgeon may also order preoperative tests such as blood counts or an EKG (electrocardiogram) to aid in preparing for the procedure.
Arthroscopic knee surgery is typically an outpatient procedure, which means the patient will return home the day of the surgery. The patient will probably be asked to arrive at the surgery center an hour or two before surgery, and the patient will not be able to drink or eat anything after midnight the night before the surgery. The patient needs to make arrangements to be driven home after surgery.
Knee arthroscopy can be performed under local anesthesia (numbs the knee), regional anesthesia (numbs below the waist), or general anesthesia (patient is asleep). The anesthesiologist will help the patient determine which method is best for their particular case.
What to Expect During Knee Arthroscopy Surgery
After anesthesia is administered, the orthopedic surgeon will make a few small incisions in the knee and then fill the knee joint with a sterile solution that rinses out any cloudy or murky fluid.
The surgeon will first insert the arthroscope (small camera) into one of the small incisions (portals). The arthroscope transmits the detailed images of the inside of the knee up onto a television monitor for the surgeon to view the inside of the knee joint. The surgeon will move the scope around the inside of the knee in order to see and evaluate various areas. The surgeon first diagnoses the extent of the problem, and then, depending on what is needed, inserts small surgical instruments (biters, probes, scissors, shavers, lasers, etc.) through separate incisions to clip torn structures, remove torn cartilage, repair cartilage, or do other procedures. This portion of the procedure typically takes thirty minutes to over an hour. The amount of time the procedure takes depends on the extent of the patient’s problems or injuries and the necessary treatments.
Usually two to four small incisions total are needed for knee arthroscopy surgery. The surgeon may close the small incisions with a stitch or with steri-strips (small band aids) and then overlay them with a soft bandage.
What to Expect After Knee Arthroscopy Surgery
After the knee arthroscopy, the patient will be moved to a recovery room and should be able to return home within one or two hours. Usually a patient can return fully to routine daily activities after about three weeks, but returning to sports may take two to three months.
The patient will need someone to drive them home. Following the surgeon’s recovery instructions is extremely important after surgery, and the patient should have someone come check on him or her the first evening they are home. The patient’s leg should be elevated as much as possible the first several days following surgery, and the patient should, as recommended by their doctor, apply ice to alleviate pain and swelling. Most patients can return to a sitting job after about a week, but patients’ whose job entails a large amount of movement or heavy lifting will most likely take longer.
The patient will have a dressing covering the knee when they leave the hospital, and it is important to keep the incisions dry and clean. The surgeon will inform the patient of when they are allowed to first shower or bathe following surgery and when the dressing should be changed.
Most patients will use crutches or other assistance following arthroscopic surgery. The surgeon will inform the patient of when it is safe to bear weight on the foot and leg.
Usually patients are able to drive one to three weeks following arthroscopic knee surgery. The surgeon will inform the patient of when they may begin driving. This recommendation is based off several factors including:
- Nature of the procedure
- Level of pain
- How well the patient can control the knee
- Whether the patient is taking narcotic pain medications
- The knee involved
- Whether the patient drives an automatic or stick shift
The surgeon will prescribe pain medication following surgery and may also suggest medication such as aspirin to decrease the risk of blood clots.
Knee strengthening exercises:
The patient will need to regularly exercise their knee for several weeks post surgery. Special therapeutic exercises play a crucial role in the recover process, and a formal physical therapy program may be recommended for enhanced results. Therapeutic exercise strengthens the muscles of the leg and knee and restores motion.
Outcomes of Knee Arthroscopy Surgery
The final outcome of knee arthroscopy surgery heavily depends on the degree of damage to the knee originally and what was done during surgery. For severe injuries, full recovery may not be possible, and the patient may be required to change their lifestyle or limit their activities, including practicing low-impact exercise alternatives.
What Is Sports Medicine?
Sports medicine, specifically, is a multidisciplinary field connected with orthopedics, because it particularly focuses on musculoskeletal problems or injuries due to sports, exercise, and recreational activities. Sports medicine is an area of orthopedics that is rapidly growing, and many sports medicine doctors are board certified orthopedic surgeons.
These pages are not intended to provide medical or surgical advice or physician instruction on the medical care or treatment. If you are a patient, consult with your doctor about treatment options that may be appropriate for your medical condition.