Meniscectomy

Arthroscopic Meniscectomy-Minimally Invasive Arthroscopic Surgery for Torn Meniscus Cartilage in the Knee

Last updated: December 31, 2009

Overview

Arthroscopic meniscectomy is an outpatient minimally invasive surgical procedure used to treat a torn meniscus cartilage in the knee. The meniscus is often torn as a result of sport-related injury in athletic individuals. Only the torn segment of the meniscus is removed. Some patients require assistance from physical therapists postoperatively. The average time of return to all activities is 4-6 weeks after the surgery.

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Arthroscopic Meniscectomy - MRI showing a torn meniscus
Arthroscopic Meniscectomy -
MRI showing a torn meniscus

Symptoms & Diagnosis

Characteristics of torn meniscus cartilage in the knee

A torn meniscus usually produces swelling and well-localized pain in the knee. The pain is made worse by twisting or squatting motions. Sometimes a fragment of torn meniscus can displace inside the knee in such a way as to "lock" the knee, allowing only a toggle of motion.


Types

A tear can occur in one or more directions in the meniscus. Traumatic tears are usually vertical whereas degenerative tears are usually horizontal. The shape that the meniscus and its torn portion assume has led to names like "bucket handle tear," "parrot beak tear," and others. Sometimes the meniscus deteriorates to the point where the tear is no longer a "clean" tear, but rather the meniscus is shredded and resembles crab meat.


Similar conditions

ometimes the symptoms from a torn meniscus can be confused with those from significant knee arthritis with loose articular (gliding) cartilage. Occasionally a chronically inflammed knee will produce similar findings. Usually these conditions can be distinguished from a torn meniscus by history and a good physical exam. Sometimes, though, they can only be distinguished by MRI or diagnostic arthroscopy.


Incidence and risk factors

Meniscal tears are common especially in people participating in sports. Traumatic tears usually occur as a result of a twisting or hyperflexion injury. Degenerative tears are more common in people over 40 and may occur without a specific injury. Smokers are at higher risk for degenerative tears.

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Arthroscopic Meniscectomy - Types of Meniscal Tears
Arthroscopic Meniscectomy -
Types of Meniscal Tears
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Arthroscopic Meniscectomy -
MRI showing a torn meniscus

Diagnosis

A torn meniscus is diagnosed on the basis of the patient's history and a thorough physical exam. An MRI is often used to confirm the diagnosis.

Medications

Medications

Medications can relieve pain and swelling temporarily, but will not actually produce healing of the torn meniscus.


Exercises

Quadriceps strengthening exercises can help prevent the muscle atrophy that is associated with a painful, swollen knee.


Possible benefits of arthroscopic meniscectomy-minimally invasive arthroscopic surgery

When the torn part of the meniscus is removed, any catching or locking should be gone immediately. Pain is usually minimal by 1 week after surgery. Full motion of the knee returns as the swelling disappears, usually within 4-6 weeks after the surgery.


Types of surgery recommended

The surgical treatment for a torn meniscus is either to remove or repair the torn segment of the meniscus using an arthroscope and specially designed instruments. Because only the outer 1/4 of the meniscus has blood supply, repairs are successful when the tear occurs in this vascular region of the meniscus. Tears in the non-vascular region are unlikely to heal and therefore are removed. (For information on meniscal repair, see article on that topic).


Who should consider arthroscopic meniscectomy-minimally invasive arthroscopic surgery?

Occasionally the symptoms from a degenerative tear will quiet down without surgery. Surgery for a torn meniscus should be considered when the knee is "locked", the knee is persistently swollen, the patient can not participate in normal activities, the patient understands and accepts the risks, and the surgeon is fellowship trained and experienced in arthroscopic meniscectomy.

What happens without surgery?

In the best case scenario, the symptoms of swelling and pain will resolve and the patient will be able to resume activities. In the worst case scenario, the torn fragment of meniscus will "lock" the knee, preventing all but a small amount of motion. This makes activities of daily living difficult.

Effectiveness

In the hands of an experienced fellowship trained orthopedic surgeon, removal of the torn part of a meniscus is very effective in restoring comfort and function to the knee. The knee will usually function normally for decades. If an entire meniscus needs to be removed, that section of the knee is likely to become arthritic 10-15 years later.

Urgency

Removal of a torn segment of meniscus is urgent only when the knee is locked. Even then the urgency is about the patient's comfort and ability to get around more than it is about the long term effects on the rest of the knee joint. A torn segment of meniscus that catches, locks, or produces swelling on a frequent basis should be removed relatively quickly (within a few months) so that it does not damage the articular (gliding) cartilage in the rest of the knee. Waiting to remove the mobile torn fragment can also lead to muscle atrophy and joint contracture which make it more difficult for the patient to ultimately regain normal function after surgery.

Risks

The risks of arthroscopic meniscectomy include but are not limited to infection and deep vein thrombosis ( blood clot) in the operated leg. If a clot forms and travels to the lung, the situation can be life threatening. Fortunately this is uncommon. Sometimes there will be numbness around the small scars where the instruments have entered the knee. There are also risks to anesthesia. An experienced team will take care to minimize these risks, but cannot totally eliminate them.

Managing risk

The risk of infection can be decreased by using intravenous antibiotics during surgery. If infection occurs, the patient is taken back to the operating room where the knee is washed out using arthroscopic equipment. The patient is then put on intravenous antibiotics, usually for 6 weeks depending on the organism causing the infection. If a blood clot forms in the leg, the patient is usually put on blood thinners to prevent the clot from expanding or moving. If the patient has concerns about the post operative course of events, the surgeon should be informed as soon as possible.

Preparation

Prior to surgery, the patient should have no ongoing infections, and the knee should have no sores or scratches. The patient should NOT shave the knee the day before surgery. The patient should have someone to help at home for 24-36 hours after the surgery. Because airplane flight is also associated with blood clots in the leg, we recommend that patients not travel by plane in the first 5 days after surgery. Similarly, because dental work releases bacteria into the blood stream, we recommend that dental work be put off until after the knee has fully recovered from surgery, typically 4-6 weeks. When this is not possible, we recommend antibiotic coverage around the time of the dental work.

Costs

The surgeon's office should provide a reasonable estimate of the surgeon's fee, the hospital fee, the anesthesia fee, and the degree to which these should be covered by the patient's insurance.

Surgical team

Arthroscopic meniscectomy should be performed by an orthopedic surgeon fellowship trained in arthroscopic surgery of the knee. The procedure should be done in a medical center or outpatient surgical facility that is accustomed to doing arthroscopic meniscectomies frequently.

Finding an experienced surgeon

Surgeons specializing in arthroscopic meniscectomy can be located through university schools of medicine, county medical societies or state orthopedic associations. Other resources include the American Orthopedic Society for Sports Medicine and the American Academy of Orthopedic Surgeons.


Types of surgery recommended

The surgical treatment for a torn meniscus is either to remove or repair the torn segment of the meniscus using an arthroscope and specially designed instruments. Because only the outer 1/4 of the meniscus has blood supply, repairs are successful when the tear occurs in this vascular region of the meniscus. Tears in the non-vascular region are unlikely to heal and therefore are removed. (For information on meniscal repair, see article on that topic).

Who should consider arthroscopic meniscectomy-minimally invasive arthroscopic surgery?

Occasionally the symptoms from a degenerative tear will quiet down without surgery. Surgery for a torn meniscus should be considered when the knee is "locked", the knee is persistently swollen, the patient can not participate in normal activities, the patient understands and accepts the risks, and the surgeon is fellowship trained and experienced in arthroscopic meniscectomy.

What happens without surgery?

In the best case scenario, the symptoms of swelling and pain will resolve and the patient will be able to resume activities. In the worst case scenario, the torn fragment of meniscus will "lock" the knee, preventing all but a small amount of motion. This makes activities of daily living difficult.

Effectiveness

In the hands of an experienced fellowship trained orthopedic surgeon, removal of the torn part of a meniscus is very effective in restoring comfort and function to the knee. The knee will usually function normally for decades. If an entire meniscus needs to be removed, that section of the knee is likely to become arthritic 10-15 years later.

Urgency

Removal of a torn segment of meniscus is urgent only when the knee is locked. Even then the urgency is about the patient's comfort and ability to get around more than it is about the long term effects on the rest of the knee joint. A torn segment of meniscus that catches, locks, or produces swelling on a frequent basis should be removed relatively quickly (within a few months) so that it does not damage the articular (gliding) cartilage in the rest of the knee. Waiting to remove the mobile torn fragment can also lead to muscle atrophy and joint contracture which make it more difficult for the patient to ultimately regain normal function after surgery.

Risks

The risks of arthroscopic meniscectomy include but are not limited to infection and deep vein thrombosis ( blood clot) in the operated leg. If a clot forms and travels to the lung, the situation can be life threatening. Fortunately this is uncommon. Sometimes there will be numbness around the small scars where the instruments have entered the knee. There are also risks to anesthesia. An experienced team will take care to minimize these risks, but cannot totally eliminate them.

Managing risk

The risk of infection can be decreased by using intravenous antibiotics during surgery. If infection occurs, the patient is taken back to the operating room where the knee is washed out using arthroscopic equipment. The patient is then put on intravenous antibiotics, usually for 6 weeks depending on the organism causing the infection. If a blood clot forms in the leg, the patient is usually put on blood thinners to prevent the clot from expanding or moving. If the patient has concerns about the post operative course of events, the surgeon should be informed as soon as possible.

Technical details

Once the patient is asleep or the knee is anesthetized, three small holes (portals) are made in the knee. The arthroscope is inserted into one of the portals. Another portal is used for a cannula to keep a saline solution flowing through the knee to improve visibility and maneuverability of the instruments. The third portal is for the working tools. The arthroscope and the tools are typically 4.5 mm in diameter. The entire inside of the knee is inspected, including the kneecap, the ends of the thigh and leg bones that form the knee, the menisci, and the cruciate ligaments. The tear is identified and probed with a small hook to determine where it starts and ends and how mobile it is. The torn fragment is then cut free and removed. The edge of the remaining meniscus is then shaved smooth. Any shaggy articular (gliding) cartilage is also shaved. The knee is then reinspected to make sure there are no other abnormal findings. Finally additional saline is flushed through the knee to wash out any tiny particles that may be floating around. The portals are each closed with one stitch and a long acting pain reliever is injected into the joint.

Anesthetic

Arthroscopic meniscectomy can be performed with the patient under a general anesthetic or with a spinal block. Before surgery, patients can discuss their preferences and the risks and benefits of various types of anesthesia with the anesthesiologist. Because arthroscopic surgery is done with a camera on the arthroscope, a patient who has chosen to stay awake may watch and talk to the surgeon during the procedure.

Length of arthroscopic meniscectomy-minimally invasive arthroscopic surgery

The procedure usually takes about one hour. However, the preoperative preparation and the postoperative recovery may add several hours to this time.

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Arthroscopic Meniscectomy -
Set-up for Arthroscopic Meniscectomy

Pain and pain management

In the first 24-48 hours after arthroscopic meniscectomy, the operated knee is swollen and moderately painful. However most patients are able to return to sedentary jobs by the third postoperative day. Medications used to manage pain in the first 48 hours include oral narcotics such as hydrocodone or oxycodone. Subsequently, acetaminophen or ibuprofen are sufficient. The application of ice or other cold therapeutic devices to the knee are also very helpful in controlling pain and swelling.

Use of medications

Most patients do not use any pain relievers after the first postoperative week.

Important side effects

Narcotic pain medications can cause drowsiness, slowness of breathing, difficulties emptying bowel and bladder, nausea, vomiting, and allergic reactions. Anti-inflammatory medications can cause stomach irritation, nausea and headaches. Patients who have had substantial exposure to narcotic medications or alcohol in the recent past may find that the usual doses of pain medication are less effective. For some patients, balancing the benefit and the side effects of pain medication is challenging. Patients should notify their surgeon if they have had previous difficulties with pain medication or pain control.

Hospital stay

Arthroscopic meniscectomy is an outpatient procedure. After surgery the patient remains in the recovery room until the effects of anesthesia have worn off, usually for 1-2 hours.

Hospital discharge

By the time the patient leaves the recovery room, he or she may put as much weight as tolerated on the operated limb. Many patients choose to use crutches for a few days. Staying relatively quiet, keeping the limb elevated and the knee iced for 48 hours is the best way to keep swelling to a minimum thus speeding return to full activities. During the first 48 hours, before the patient is fully up and around, it is also important to flex one's feet up and down regularly to help prevent blood clots from forming in the calf veins.

Convalescent assistance

Patients do not require a convalescent facility after arthroscopic meniscectomy. They may require some assistance with self-care for the first day or two. Driving may be difficult in the first postoperative week until the swelling has resolved enough to allow sufficient knee motion.

Physical therapy

The keys to full functional recovery are regaining knee range of motion and Quadriceps muscle strength. Both are limited as long as the knee is swollen. Many patients are able to regain their motion and strength with exercises at home. Some patients require the assistance of a physical therapist. Usually at the first post operative visit, the surgeon can determine whether or not PT is necessary.

Usual response

Most patients respond well to rehabilitation after arthroscopic meniscectomy. Usually as the swelling resolves, motion increases and it is easier to work on muscle strengthening exercises. If the exercises are difficult or painful, the patient should contact the therapist or surgeon.

Risks

Rehabilitation after arthroscopic meniscectomy carries little or no risk.

Duration of rehabilitation

Rehabilitation is continued until the knee has regained full range of motion and strength .

Returning to ordinary daily activities

Usually patients return to activities of daily living in 48 hours postoperatively. Depending on the amount of swelling, driving may be difficult for an additional 2-3 days. Returning to sports is usually discouraged until the patient has recovered full range of motion and strength. On average this takes 4-6 weeks.

Long-term patient limitations

Usually there are no limitations on the patients after full recovery and rehabilitation. However, if at the time of surgery the surgeon noted significant arthritic changes in the knee, running sports may be discouraged to slow down the progression of the arthritis.

Costs

Most of the rehabilitation after arthroscopic meniscectomy is done at home. Nevertheless, when physical therapy is required, the surgeon or therapist can provide information on the usual cost for physical therapy visits. Each insurance company has its own plan for coverage of physical therapy.

Summary of arthroscopic meniscectomy-minimally invasive arthroscopic surgery for torn meniscus cartilage in the knee

In the hands of an experienced fellowship trained orthopedic surgeon, Arthroscopic Meniscectomy ( removal of the torn part of the meniscus) can be a most effective method for restoring comfort and function to a knee with a torn meniscus.

The surgery is done on an outpatient basis.

Full recovery requires elimination of swelling, and regaining full range of motion and strength. Physical therapy is sometimes needed.

Complete recovery and return to sporting activities takes an average of 4-6 weeks.


View a list of Sports Medicine patient care services at the University of Washington Department of Orthopaedics & Sports Medicine.

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