Knee Arthroscopy

The growing interest in exercise and sports has made knee injuries common. The knee is a complex and active joint. This makes it easy to injure or to damage. Arthroscopy allows your surgeon to see into the knee to find out how bad your knee problem is, plan surgery, watch or treat knee your problem. Arthroscopy is used to treat meniscus and ligament injuries, wear and tear problems, loose bodies in the joint and problems with the kneecap. Arthroscopy typically causes much less pain than other kinds of surgery. Healing time can be much shorter, patients usually go home on the same day as their surgery. Also, it leaves small scars.

This article teaches you about knee anatomy, common knee problems and knee arthroscopy. The content and medical illustrations in this article are property of Media Partners, Inc. and have been filed with the U.S. Copyright Office.

Healthy Knee Anatomy

Normal knee anatomy (click to see larger image)

Knowing knee joint anatomy can help you to understand your knee problem. It can also help you to properly care for your knee after your surgery. Proper care often helps shorten your recovery time.

A joint is where two or more bones meet, along with the surrounding structures. The articular cartilage, synovial membranes, menisci, ligaments, muscles and tendons are the major structures of the knee.

The four bones that meet and form the knee joint are the kneecap (patella), thighbone (femur), fibula, and shinbone (tibia).

The parts of bones that touch each other are covered with articular cartilage. This cartilage is a smooth substance that protects the bones as the joint moves and the bones rub. It allows the bones to move more freely against each other without pain or wear.

The synovial membrane is a thin layer of tissue that surrounds the entire knee joint. This membrane contains synovial fluid. Synovial fluid is a slippery liquid that bathes the joint and allows for even greater freedom of movement. A piece of rubbery cartilage, called a meniscus, is found in some highly active joints. One function of the meniscus is to absorb shock. The knee joint has two meniscus (menisci) sitting atop the shinbone, between the thighbone and the shinbone. Ligaments are rope-like tissue bands that connect and support the bones of a joint. In the knee, several ligaments run from the thighbone to the shinbone and the fibula. Tendons are elastic tissues that connect muscles to the bones of a joint. When a muscle contracts it causes movement in the joint. Muscles and tendons also give added support to the joint.

Knee Problems and Repairs

Knee problems can be caused by disease or by injury. Symptoms can include pain, swelling, instability, and difficulty walking. The most common knee problems are:
• a torn ligament
• a torn meniscus
• chondromalacia
• a loose body inside the knee joint

Torn Ligament

Anterior Cruciate Ligament Tear (click to see larger image)

Sudden start-stop movements and quick changes in direction are common causes of ligament injuries. Basketball and skiing are two activities where you might use start-stop movements. A torn knee ligament can cause pain, swelling or difficulty in walking. Ligament sprains can take 4-6 weeks for recovery. Ligament injuries can also be partial or complete tears. A torn ligament needing reconstructive surgery can take a year to heal.  In addition, damage to the meniscus may be found and repaired during arthroscopy.

Ligament Reconstruction

ACL harvest (click for larger image)

Reconstructed ACL (click for larger image)

Changing your activities, taking medicines and doing physical therapy all may help. If they don’t help you enough, knee arthroscopy might be needed to decide the extent of your injury. Your surgeon can repair or reconstruct the ACL with staples or stitches. The repair is made by grafting other tissue into the injured area. Damage to collateral ligaments cannot be repaired arthroscopically.

Ligaments take a long time to heal. You may have to limit the amount of weight you put on your knee for several weeks. You’ll need a cast or splint to support your knee and use crutches to get around. Strength and range-of-motion exercises will be needed to get your muscles strong enough to support your knee. It can take a year to get back to your normal activities and even then you may need to wear a brace during sports or strenuous exercise.

Torn Meniscus

Meniscal tears (click to see larger image)

Twisting the knee joint is the most common cause of a torn meniscus. This can happen during sports or even during normal daily activity. The meniscus also becomes softer with age, making it easier to tear. Tears can occur along the edge of the meniscus or larger tears can occur deeper into the meniscus. A torn meniscus can cause catching or locking of the knee, giving way or buckling (instability) of the knee, pain or swelling. The size and location of the tear determine both treatment and recovery. Small tears need 4-6 weeks for recovery while repair of larger tears can take 3 months or more.

Meniscus Removal or Repair

Cartilage removal (click to see larger image)

During knee arthroscopy, the damaged part of the meniscus can either be repaired or removed to prevent permanent damage to the knee joint. If the tear is near the edge, the meniscus may be trimmed to smooth the rim. In most cases, it will be repaired with stitches which can make rehab longer, but your knee will better keep its shock absorbing ability. You’ll need crutches, a brace to immobilize your knee, and limited weight bearing. A full recovery is likely for a mild injury. If the meniscus was removed, you may have more problems in the future.

Chondromalacia

Chondromalacia can be caused by overuse or injury to the kneecap and is a condition where the articular cartilage of the knee bones softens. It is most common on the back of your kneecap where the kneecap rubs with straightening of the knee. As the cartilage softens, it wears away more easily during joint movements. The cartilage can also be damaged by directly injuring the knee. Or the cartilage may just thin with age, which can cause catching or locking of the knee, giving way or buckling of the knee (instability), pain or swelling.

Cartilage defects

In chondromalcacia, if the articular cartilage is worn or damaged, the bones will probably rub against each other. This can cause pain walking down hill or down stairs, pain after sitting for long periods, getting out of a chair or aching in the knee area.

Rest, NSAIDs and physical therapy to stretch and strengthen the hamstrings and quads should be tried before choosing to have surgery. If medicine and physical therapy don’t help, knee arthroscopy may be needed. During the surgery, your surgeon can make the damaged cartilage smooth as well as smoothing out any rough or worn surfaces on the bone.

Recovery from mild damage to the surface cartilage can take 4-6 weeks; more severe damage can take 3-4 months.

Loose Body (Joint Mouse)

Any free-floating object in the synovial fluid of the knee is known as a loose body or joint mouse. It can be a fragment of bone, cartilage, or meniscus. It can also be a piece of glass, metal or any foreign object. A loose body isn’t usually noticeable until it lodges somewhere in the joint. Your symptoms can change depending upon the exact location within your knee. A loose body can cause catching or locking of the knee, giving way or buckling of the knee (instability), pain or swelling.

Removal of lose body from the joint space

Arthroscopy allows your surgeon to find the loose body in your knee joint and remove it.

Other knee problems

Arthroscopy can also be used to diagnose and treat misalignment of the kneecap, wear and tear injuries, and cracks in the surface cartilage on the ends of the bones. Loose bodies and bone spurs are also common findings. Biopsy can also be done arthroscopically.

What is Arthroscopy?

Arthroscopy is a way to view and repair the inside of a joint. Your surgeon uses a soft, pencil-thin tube called an arthroscope. This tube has a tiny video camera, a light and fluid-exchange paths. The arthroscope, and other small instruments, are inserted into the knee joint through small incisions. From one to about four incisions are usually needed. Fluid is pumped into the joint to expand the space, giving your surgeon better images. The video camera captures the images seen through the arthroscope and displays them on a video monitor.

Because only small incisions are made, you usually have arthroscopy as an outpatient. This means, you can go home the same day you have your surgery.

Questions to Ask Your Surgeon About Arthroscopy

• Should I take my daily medicines before surgery?
• How much pain can I expect after surgery and how will the pain be controlled?
• Will I be on crutches, a walker or a cane? For how long? Where can I get these? Should I get them before surgery? Should I bring them to the hospital with me?
• Will I need a brace? For how long? Where do I get one? Should I get them before surgery? Should I bring it to the hospital with me?
• How soon will I be able to drive?
• How soon until I can get back to my normal activities like sex or going back to work?
• How soon until I can get back to more strenuous activities like sports or exercise?

Write down the answers so you don’t forget.

Getting Ready for Arthroscopy Surgery

Since arthroscopy is not emergency surgery, you will have plenty of time to prepare. Your surgeon will likely give you instructions to do 2 weeks before surgery:

• Always tell your surgeon or nurse what medicines you are taking, even medicines, supplements, or herbs you take without a prescription.
• Stop taking medicines that make it harder for your blood to clot including aspirin, ibuprofen (Advil, Motrin), naproxen (Naprosyn, Aleve), and other medicines.
• Ask your surgeon which of your daily medicines you should take on the day of surgery.
• Tell your surgeon if you drink more than 1 or 2 drinks of alcohol a day.
• If you smoke, quit. Ask your surgeon for help quitting—don’t use a nicotine patch. Smoking (nicotine) can slow down wound and bone healing and increase your risk of wound infection.
• Be sure to tell your surgeon about a cold, flu, fever, herpes breakout, or other illness or infection that happens between the time you see him and a few days before surgery. You may have to postpone surgery to prevent infection in your knee.
• Get your home ready for your return home. Set up an area where you won’t have to go up and down stairs and rearrange furniture so you can get around with crutches.
• If possible, strengthen your leg muscles with exercises. This can help you do exercises after surgery as well.

The night before surgery scrub the leg with the bad knee from your hip to your toes for 10 minutes using a germ killing soap like Dial.

On the day of surgery:

• Do not drink or eat anything for 6 to 12 hours before the procedure.
• Take your daily medicines that your surgeon says it’s OK to take with a small sip of water.
• Arrive on time at the hospital or surgery center. You will likely have to show that you have brought someone with you and they will wait and drive you home.
• Wear loose fitting clothing that you can pull over the bulky bandage on your knee. Sweat pants or basketball shorts are good choices.
• Bring your crutches, cane or brace with you.
• Your surgeon will ask you to sign a surgical consent form if you haven’t signed one already. By signing the consent form you are saying that you understand the risks, benefits and possible alternatives to arthroscopy and that you give your permission to go ahead with surgery.
• You may be given a compression stocking to wear on the unaffected leg to help prevent blood clots form forming in the veins of your leg. If you are at high risk for blood clots, you may be given anticlotting medicine instead of or in addition to the compression stocking.

During Arthroscopy Surgery

Pre-operative Area

After checking in for surgery, you will go to the pre-operative area. Usually, your blood pressure, pulse and temperature are monitored in this area. Your heart and lungs may be listened to with a stethoscope. Here, you will probably meet your anesthesiologist. She will talk to you about anesthesia and answer your questions. An intravenous tube (IV) may be placed into your arm or hand. The IV puts medicine and fluids into your body. It remains in place until after your surgery. You can probably have a visitor in the pre-operative area.

Operating Room

When it’s time, your nurse will bring you to the operating room (OR). Here, your leg will probably be shaved and scrubbed clean with an anti-bacterial soap. A pressure band (tourniquet) may be applied to your thigh to restrict blood flow and reduce bleeding.

Anesthesia

The three types of anesthesia used for arthroscopy are:

• local anesthesia—numbs your knee area
• epidural anesthesia—numbs you below the waist
• general anesthesia—puts you to sleep

Usually, local or epidural anesthesia is used. If it is, you’ll be awake during your surgery. Sometimes, for more complex surgery, general anesthesia is used.

What You’ll Feel

With a local or epidural, a needle is used to deliver the anesthetic. You’ll feel the sting of this needle. But, once the anesthetic has taken affect, you shouldn’t feel any pain during surgery. You may feel some pressure or tugging on the knee as your surgeon works. You can tell the surgeon or nurse if anything bothers you. If you have general anesthesia, the medicine is put into your IV.

Arthroscopic Surgery

These are some of the problems that can be examined and possibly repaired made during knee arthroscopy:
• synotivits—inflammation of the synovial membrane
• irritations in the plica
• chondromalacia
• meniscal tears
• problems with the articular surfaces of the tibia and fibula (arthritis)
• problems with the anterior cruciate and posterior cruciate ligaments
• loose bodies
• misalignment of the kneecap

A small incision is made to allow sterile fluid to be pumped into your knee to expand the space and expose the joint and injured area. The fluid allows the surgeon to see your joint more easily. The pressure of this fluid also helps control bleeding. The arthroscope—a tube with a tiny video camera on the end—is then inserted. The inside of your knee joint is now viewed on a video monitor. Several more small incisions may be made for inserting other instruments into your knee. Commonly used instruments are forceps, scissors, a blunt hook, a shaver and a burr. These instruments are used to grasp, repair or remove bits of tissue or bone. These instruments are guided by the view on the video monitor. This part of the procedure usually lasts between 30 minutes to 1.5 hours depending on how much work is needed to repair your knee. When finished, the fluid is drained out. As the surgeon finishes, your incisions are closed with sutures or adhesive strips. Then your knee is bandaged with a compression bandage to reduce swelling and bleeding.

Risks of Having Surgery

Knee arthroscopy is commonly performed and generally safe. However, surgery always has risks. Though not common, sometimes complications occur such as:
• Infection of the surgical wounds
• Blood clots (phlebitis) in your legs
• Accumulation of blood in the knee (hemarthrosis)
• Damage to other parts of your knee
• Instrument breakage

Other possible complications are weakened joint and resulting arthritis, knee stiffness or trouble breathing while coming out of general anesthesia. You may also have loss of feeling in the skin over the knee. Some patients’ knee problems are not corrected with surgery. Sometimes your surgeon may find out during your surgery that arthroscopy cannot help your knee problem. Risks are specific to your knee problem and your surgery, so ask your surgeon to tell you which risks likely apply to you.

After Arthroscopic Surgery

Recovery Room

At the end of your surgery, you will be taken to the recovery room. You usually stay here for one or two hours, depending on your type of surgery. You will be in recovery until the effects of anesthesia have worn off, you’re past the stage where complications are likely to occur and you’re reasonably free of pain. You can usually have a visitor in the recovery room.

Your blood pressure, pulse, respiration and temperature are typically closely monitored. You may be given fluids and medicines for pain or nausea from anesthesia. You’ll have an ice pack on your knee to help keep down the swelling. Your surgical leg circulation and sensations are checked. It’s important to pedal and move your feet often to keep blood circulating in your legs and prevent blood clots.

Discharge – Going Home

Your surgeon decides when you’re ready to be discharged. Discharge is based on your recovery from anesthesia and whether your pain is under control. If you have problems or need to be watched longer, you may be admitted to the hospital. When you’re discharged, someone will have to drive you home.

You may have a big bandage, brace, or ice pack on your knee that goes home with you. A nurse usually reviews home-going instructions with you, gets your prescriptions, tells you when to make a follow-up appointment with your surgeon and what to do if you have problems when you get home. It may take several hours to regain feeling in the affected knee. In the meantime, be careful not to bump or injure your knee. A physical therapist may speak with you about exercises you can do. You may also go home with the compression stocking on your unaffected leg.

Recovery At Home

Knowing how to care for your knee once you get home will make a big difference in your recovery and results. How fast your knee heals depends on your age, your job, your fitness level before surgery, how active you are or want to be, and how much time you’re willing to spend on getting your knee back to normal. Everyone’s recovery time is based on their overall health and the extent of their knee surgery.

Before going home, your surgeon may give you a set of instructions similar to these:
• Help at home: For the first 24 hours after surgery you should not be left alone. This is if you need help or unforeseen problems arise; remember you cannot drive.
• Rest and walking: You may feel groggy for the first 24-48 hours. Rest and give your body time to recover from surgery and anesthesia. Do not begin walking before your surgeons says it’s OK, usually after 3 days. Be sure to wear your brace if your doctor ordered one. Adjust the brace to give you support but it shouldn’t be too tight. While you are resting, point and wiggle your toes and flex and rotate your foot and ankle for the first few weeks. Be careful not to trip and fall. Keep your hands free to help you balance.
• Medicine: Your surgeon may prescribe antibiotics to prevent infection and medicine to relieve pain and discomfort. Take all medicines exactly as prescribed.
• For pain and swelling: Your knee is likely to feel sore and be swollen for at least a week. For the first 24-48 hours ice your knee as directed. Rest and elevate your knee by supporting so that your knee is higher than your heart as much as possible. Especially after physical therapy and exercise, and always at night. Take pain medicine as prescribed. (See R.I.C.E. Therapy)
• Crutches Use crutches or a cane as directed by your surgeon. You can gradually put more weight on your leg as your knee heals.
• Wound care: Keep your wound and bandage dry and clean. With your surgeon’s permission, you may remove your bandage a few days after the surgery. At this time you may shower as usual—use a nonslip mat and hand rails when possible until your knee is strong and stable. Do not soak your incisions in a bathtub. Check your incision every day for redness, tenderness or drainage. You may see bruising, slight swelling and a small amount of blood on the bandage.
• Exercise: Begin a strengthening and range of motion exercise program as instructed by your surgeon or physical therapist. Physical therapy can greatly help your healing progress. Don’t forget to ice your knee after therapy.
• Return to routine: Return to daily activities and work as soon as possible. You may start vigorous exercise in 6-8 weeks or as instructed by your surgeon. Avoid driving for 3 weeks. Avoid high impact exercises until you’ve made a complete recovery and your surgeon says it’s OK.

When to call your Surgeon
Call your surgeon to make a follow-up appointment.

Expectations After Arthroscopy

Recovery Time

There is often little pain during recovery from knee arthroscopy. You should expect complete recovery without complications. Allow 6-8 weeks for recovery from the surgery; full recovery of the joint can take up to a year. Each patient is unique. The time needed for recovery depends upon your injury, your fitness level and if you had complications. After knee arthroscopy you will have small scars on your knee from the cuts.

A “simple” surgery, like loose body removal, with no added complications, can heal rapidly. Arthritis is one kind of complication that makes healing difficult. In fact, up to 50% of patients with arthritis might not improve after surgery. Ligament reconstruction is a more complex surgery and usually needs more healing time.

Often, patients return to work within a few days. You can probably return to most of your physical activities within 6-8 weeks. Expect to return to intense physical activity only with your surgeon’s permission.

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