A knee scope, or knee arthroscopy, is a relatively simple procedure that allows a physician to treat intra-articular pathology, such as damage to the cartilage on the end of the bones (i.e., arthritis), and/or injury to the meniscus. In the past this required an arthrotomy (a large incision opening up the knee joint). In general, a knee arthroscopy can be done through two or three small incisions placed around the kneecap. The surgeon then inserts a small scope, which allows him to see within the knee, and specially designed instruments which allow him to repair and/or remove the injured or damaged tissue. This is advantageous from the standpoint that it can be done as an outpatient procedure with relatively little pain, at least in comparison to an arthrotomy. Generally the procedure takes approximately one hour, depending on the specific procedure performed, and you can go home on the same day.
The most common reason for a knee scope is a tear in the cartilaginous disc, otherwise known as a meniscus, which sits within the knee joint between the femur and the tibia. It is shaped like the letter C from which the name “meniscus” is derived; literally meaning “crescent shaped” or C-shaped. When torn a piece of the meniscus can be caught between the joint or flip in and out of the joint causing localized knee pain along with a catching or locking sensation. In the majority of cases this tear should be surgically removed, eliminating the pain and reducing the potential of further damage to the joint. On occasion, in the right patient and with the right type of tear, it can be repaired. When the meniscus is removed it is only the part that is torn. In the past the whole meniscus was removed. We now know that removing the meniscus entirely leads to arthritis in 10-15 years and this practice has been largely abandoned. There is no evidence to date that removing part of the meniscus leads to arthritis in the future.
Chondromalacia / Arthritis
Another reason for a knee scope is when the articular cartilage on the end of the bones is damaged, i.e. chondromalacia or arthritis. Chondromalacia literally means “bad cartilage” (chondro = cartilage; malacia = bad). Most people’s perspective when they hear the have “arthritis” is that their joint is totally destroyed, i.e., they no longer have any cartilage on the end of their bones. However there are varying degrees of severity of arthritis ranging from a simple softening of the cartilage to a wearing down to bone. In fact, there are four distinct grades of injury to the cartilage. Normally the cartilage looks like and is as smooth and firm as a linoleum floor, but it can get soft like a pillow (Grade 1); look like a shag carpet (Grade 2); have cracks in the pavement (Grade 3); or look like a pothole, i.e., cartilage worn done to the underlying bone (Grade 4).
This irregular surface can produce pain, swelling, and a catching or in some cases a grinding sensation. Using specialized surgical equipment the roughened surface of the cartilage is removed and the surfaced smoothed over. If it’s a Grade 4 injury several small holes can be made in the bone. This can lead to a new layer of scar cartilage and although it’s better than nothing it is not as good as the native cartilage that was lost. This procedure is known as a chondroplasty (literally: reshaping the cartilage; chondro = cartilage; plasty = reshape).
Keep in mind that although you will benefit from this procedure, this is arthritis and to date there is no cure, short of a total knee replacement. There is nothing available on the market which regrows the cartilage. The procedure can be useful for reducing and/or limiting some of the symptoms associated with arthritis, but ultimately, these may recur. In addition, it generally takes longer to recover from this procedure, in the order of 2-3 months, but may even take up to one year.
A plica (literally: fold) is a band of tissue within the knee that is left behind after your knee is formed in utero (in the womb). It is present in most people but in some it can be large and rub against the cartilage or bone causing inflammation, pain, and occasionally a snapping sensation. You can go years without a problem and then after a minor or major injury to your knee it becomes symptomatic. Surgery involves removing the band of tissue arthroscopically with a small shaver eliminating the pain.
What to expect After the Surgery
The amount of pain after a knee scope varies tremendously and is dependent on the procedure performed and individual pain tolerances. Most people do very well however, especially compared to the old open (arthrotomy) technique. Most surgeons will use a combination of intraarticular anesthetic and a narcotic and/or a non-steroidal anti inflammatory (NSAID) (like ibuprofen) for pain control. The intraarticular injection is usually a long acting novacaine-like drug with of without morphine. Pain relief can last for 4-5 hrs and in some patients into the next day. It’s important to stay in front of the pain by taking the prescribed pain medication before the numbing medicine wears off completely, and to take it regularly for the first 2-3 days. After that you may take it on an as needed basis.
Most of the pain associated with the surgery occurs within the first 2 weeks, with the first week being the worst; it is generally gone within the first 4-6 weeks, but on occasion can linger for 2-4 months. Controlling the swelling is key to pain control. This is best done by minimizing (though not eliminating) activity, keeping your leg elevated, and applying ice and compression (ace wrap).
A swollen knee is very common after a knee arthroscopy due to the trauma from the surgery and the fluid that is pumped into your knee during the procedure. It can lead to swelling in your foot, ankle, and calf but generally not your thigh. This should resolve in 4-6 weeks but again can take as long as 2-4 months. If thigh swelling occurs this could be a sign of a blood clot and you should be seen immediately. Most swelling can be treated successfully with elevation of the leg (foot above your knee and knee above your heart – water runs down hill), ice, and compression (either an ace wrap or compressive stockings). If swelling is limited to the knee only, the ace wrap can be applied to the knee only; but if the whole leg is swollen, it should be applied from the toes to the thigh or a compressive stocking should be used.
Activities immediately after the surgery should be kept at a minimum although it is important to keep mobile to avoid the possibility of a blood clot. Most patients are able to walk on their knee the following day, although some do often require the use of crutches and/or a walker until they are able to ambulate relatively pain-free. In some cases this may take as long as a week or two. Bracing, unless the meniscus is repaired, is generally not needed or required. Range of motion (ROM) exercises (flexing and extending the knee) and isometric quadriceps exercises can be started the first postoperative day (2-3 times/day for 5-10 minutes) as tolerated. Formal physical therapy is generally not required after a simple knee scope but can be started at the physician discretion a week or two after the surgery.
More specifically, when the meniscus has been removed or a chondroplasty performed, you may begin weight-bearing the next day but should use crutches or a walker for stability or until you can walk normally with little pain. In most cases, if it was only the meniscus that was torn, you will be able to resume your normal activities including sports or heavy labor in approximately 4-6 weeks; prior to that, your activities should be limited to walking or similar light activity. The timeframe for returning to sports or a laboring job after a chondroplasty will vary depending on the severity of arthritis and your individual pain tolerances, typically 2-4 months.
When the meniscus is repaired (vs. removed) a brace may be used to restrict the range of motion of the knee initially and will be gradual increased over time (6-8 wks). Weight-bearing may also be restricted for the first 2 months with return to sports or a laboring job in 3-4 months.
Bandages, Showering, and Sutures
The postoperative dressing/bandage should be left in place for 4 days after the surgery. This allows time for the wound to heal over with a thin layer of skin before exposing it to an unsterile environment thereby reducing the risk of infection. Expect bleeding to occur which can sometimes seep through the bandage; unless this is severe the bandage should be left in place and reinforced as necessary. Showering can start after the bandage is removed on the fourth day but do not soak the knee for the first 3 weeks, i.e., in a bath, hot tub, lake, or pool. The knee should be washed as normal with soap and water. Redress the wound with a dry dressing and ace wrap if there is continued drainage but is not necessary if no drainage or swelling is present. Sutures, if placed, will be removed the first week of two at surgeon’s discretion.
Potential Risks/Surgical Complications
Although the majority of knee scopes have relatively few complications, there are risks associated with any surgery. These include but are not limited to the risk of a general anesthetic, nerve/artery damage, infection, incomplete or no relief of pain, knee stiffness, reflex sympathetic dystrophy, and deep vein thrombosis (leg blood clot) leading to a possible pulmonary embolism (lung blood clot). The risk of a general anesthetic should be discussed with the anesthesiologist.
The risk of a major nerve or artery damage is rare but not impossible. More likely (but still low risk) is an injury to a small skin nerve near the incision which could lead to a small area of numbness around the wound. This is usually temporary until the nerve recovers but could be permanent.
The risk of infection though not impossible is exceedingly low since during the course of the procedure several liters of fluid are run through the knee joint. Higher infection rates are seen in smokers, and in patients with diabetes and/or vascular disease. There are two different types of infections after a knee scope: superficial and deep. Superficial infections are characterized by redness and perhaps purulent (pus) drainage around the wound, and possibly a fever, chills or night sweats. It can usually be treated effectively with antibiotics by mouth for a week to ten days. A deep infection is one that is within the knee joint itself. The whole knee is usually swollen and red, may be warm to the touch (compared to the other knee) and is extremely painful to move. If caught early and mild it may be treated with drainage and antibiotics by mouth; if caught late or is severe it may require a repeat knee scope to washout the infection and intravenous antibiotics.
Postoperative Pain Relief
In general, the amount and duration of pain relief resulting from the surgery is proportional to the amount of arthritis within the knee. If little or no arthritis is present most, if not all, patients have near complete pain relief.
Knee stiffness is usually a short term problem and is often proportional to the amount of swelling present after the surgery. Long term problems with knee stiffness are rare and are usually due to lack of participation in a home or formal exercise program.
Reflex Sympathetic Dystrophy (RSD)
RSD or chronic regional pain syndrome (CRPS) (as it is now known) is a very rare but severe reaction to trauma or surgery. For reasons we don’t quite understand the autonomic nerves (nerves you can’t control) in an extremity go haywire, leading to severe pain and skin color changes, and potentially over time to knee stiffness. When this rare condition occurs it requires a multidisciplinary treatment approach and can be worse than the original condition.
Deep Vein Thrombosis/Pulmonary Embolism (Blood Clots)
Blood clots also are exceedingly rare but can occur as a result of inactivity. The risk is higher if you have had a prior blood clot so please inform your surgeon if you have. He may choose to treat you post operatively with a blood thinner. In the worst case a blood clot in your leg can break free and travel to your lung. This can lead to chest pain, shortness of breath, or if severe possibly even death. If severe, it may require a hospitalization to treat.
Negative Knee Scope
Your clinical diagnosis was based on a conglomeration of symptoms, physical exam, x-rays, magnetic resonance imaging (MRI), and non-surgical treatment. In the vast majority of cases we confirm the diagnosis at surgery, although it may be more of less severe than expected. No test or exam is 100% accurate however, and it is possible that your surgeon informs you after the surgery that he found another source of your pain, (i.e., your MRI suggested a tear in the meniscus but he found chondromalacia/arthritis in that region instead), or that he did not find a reason for your pain, (i.e., negative knee scope).
Reasons to Call or go to the Emergency Room
Please feel free to call if there is any concern before or after your surgery. It is usually best to call between office hours (8-5 Monday through Friday: (513) 791-6611 to speak with the surgeon who performed the surgery, his medical assistant, or our nurse. In an emergency the on-call physician may be reached after hours through our office phone number. Please identify yourself, the nature of the problem, the surgery performed, when it was performed, and by which physician. Reasons to call may include (but not necessary limited to) the following:
- Excessive swelling, bleeding, or pain.
- Redness around the wound or knee; or red streaks up or down your leg.
- Excessive drainage from the wound especially if pus-like.
- Fever above 102.5 deg Fahrenheit.
- Shortness of breath or chest pain, particularly in the face of a large swollen leg.