Anatomy of the Knee Joint

The largest joint in the body, the knee is made up of the lower end of the thighbone (femur), the upper end of the shinbone (tibia), and the kneecap (patella). The ends of these bones, where they touch, are covered with articular cartilage, a smooth substance that protects the bones and enables them to move easily. Between the femur and tibia are C-shaped wedges of cartilage, called menisci, that act as shock absorbers to cushion the joint. Large ligaments holding the femur and tibia together provide stability and long thigh muscles give the knee strength. All remaining surfaces of the knee are covered by a thin lining, or synovial membrane, that releases fluid to lubricate the cartilage, reducing friction to nearly zero in a healthy knee. Normally, these components work together in harmony, but when disrupted by disease or injury the result can be pain, muscle weakness and reduced function.

What is Knee Arthroscopy?

Arthroscopy is a minimally invasive surgical procedure used by orthopaedic surgeons to visualize, diagnose and treat problems inside the joint. Your doctor may recommend knee arthroscopy if you have a painful condition that does not respond to nonsurgical treatments such as rest, physical therapy, and medications or injections to reduce inflammation. Your orthopaedic surgeon may use knee arthroscopy to evaluate, repair or remove damaged tissue that is the result of an injury or one of a variety of orthopaedic conditions. Knee arthroscopy is commonly used for: removal or repair of torn meniscal cartilage, reconstruction of a torn anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL), trimming of torn pieces of articular cartilage, restoration of damaged articular cartilage, removal of loose fragments of bone or cartilage, and removal of inflamed synovial tissue.

Preparing for Minimally Invasive Surgery of the Knee

Once the decision to have surgery is made, you may be asked you to see your primary care physician to be sure you do not have any medical problems that need to be addressed before surgery. Additional tests may be needed, such as blood and urine samples, electrocardiogram (EKG), or chest X-ray. If you have certain health risks, a more extensive evaluation may be required prior to surgery. Be sure to inform your othopaedic surgeon of any medications or supplements you take, as these may need to be stopped prior to surgery.

Knee arthroscopy is almost always performed on an outpatient basis, which means you will not be required to stay overnight in the hospital. It is very important that you follow all instructions regarding when to stop eating or drinking prior to surgery, and when to arrive at the hospital.

Surgery

Before the operation, you will be evaluated by a member of the anesthesia team. Knee arthroscopy can be performed using local anesthesia (only your knee is numb), regional anesthesia (you are awake but numb from the waist down), or general anesthesia (you are put to sleep). If your surgery is performed under local or regional anesthesia, you may be able to watch the procedure on a television monitor. The anesthesia team, with your input, will determine the best option for you. Your surgeon will see you before the surgery and sign your knee to verify the surgical site and procedure.

Your orthopaedic surgeon will begin the procedure by making a few small incisions in your knee. A sterile solution will be used to fill the knee joint and rinse away any cloudy fluid, resulting in a clearer, more detailed view inside the knee. Images from the arthroscope will be projected onto a monitor, allowing a thorough evaluation of the inside of the your joint. Once the problem has been diagnosed and any necessary treatment identified, your surgeon will insert specialized instruments, such as scissors, motorized shavers, electric cauterizers or suture devices. This part of the procedure may last for 30 minutes to over an hour, depending upon the findings and the treatment necessary. Your incisions may be closed with a stitch or small adhesive bandage strips, then covered with a soft bandage.

You will remain in the recovery room for 1 or 2 hours after surgery. During that time, nurses will monitor your responsiveness and recovery from the anesthesia, and provide pain medication, if needed. When you are ready to be discharged, you will be given instructions covering medications, need for ice and elevation, weight bearing restrictions and dressing care. Be sure to have someone with you to drive you home.

Recovery

Although recovery from knee arthroscopy is much faster than recovery from traditional open knee surgery, it is important to follow your orthopaedic surgeon’s instructions very carefully. You should expect to use crutches or other assistance after arthroscopic surgery until your surgeon tells you it is safe to put weight on your foot and leg. If you are staying alone, you should ask someone to check on you the first evening you are home.

Keep your leg elevated as much as possible for the first few days and apply ice as recommended to relieve swelling and pain. The incisions should be kept clean and dry, and the dressing should be changed as instructed. Your surgeon will tell you when you can shower or bathe. Pain medication can be prescribed to help relieve discomfort and other medications, such as aspirin, may also be recommended to lessen the risk of developing a blood clot. More detailed instructions, as dictated by the specific procedure you had, will be given to you and can also be found for that procedure on our website.

A follow-up visit will be scheduled for several days after surgery to check your progress, review findings and continue/advance your postoperative treatment program.

  • Exercise—Therapeutic exercise will play an important role in how well you recover. You should exercise your knee regularly for several weeks after surgery to restore motion and strengthen the muscles of your leg and knee. A formal physical therapy program may be prescribed to optimize your final result.
  • Driving—Patients are usually able to safely resume driving from 1 to 3 weeks after the procedure, depending on a number of factors to be discussed with your surgeon. These include: which knee is involved, whether your car is automatic or standard transmission, the nature of your procedure, your level of pain, whether you are using narcotic pain medications, and how well you can control your knee.

Complications

As with any surgery, there are risks associated with knee arthroscopy. These occur infrequently and are typically minor and treatable. Potential postoperative problems include infection, blood clots and accumulation of blood in the knee.

  • Warning signs—Certain symptoms, although uncommon, may indicate a more serious issue. Call your orthopaedic surgeon immediately if you experience any of the following: fever, chills, persistent warmth or redness around the knee, persistent or increased pain, significant swelling in your knee, increasing pain in your calf muscle.

Outcomes

Unless your arthroscopic surgery was for ligament reconstruction or meniscal repair (in meniscus repair, the meniscus is sewn back together, versus partial meniscal resection, when the damaged parts are removed), you may be able to return to most physical activities within 2 to 4 weeks, or even sooner. Higher-impact activities may need to be avoided for a longer period time. If your job involves heavy work, it may be longer before you can return to work. You should talk to your doctor before resuming any intense physical activities.

The time needed for recovery varies according to the patient, the condition of the joint, and the extent of damage and repairs required. Severe problems or more complicated procedures may require longer. In some instances, a full recovery may not be possible and you may need to make certain lifestyle changes, such as limiting certain activities or finding low-impact exercise alternatives. For all patients, following the guidelines and rehabilitation plan of your orthopaedic surgeon is vital to a successful outcome.