FAQ Category: Knee

You may be referring to a procedure called autologous chondrocyte implantation (ACI). First the surgeon débrides (removes dead cells) the damaged area. This creates a hole that is covered with a thin piece of bone.

Normal, healthy cartilage cells are removed before closing up the hole. These are called chondrocytes. They are sent to a special lab where scientists use them to grow more chondrocytes. Up to 10 million new cells can be made this way.

When the cells are ready, the surgeon injects them underneath the bone flap right into the defect. As they grow and mature, the hole fills in with smooth cartilage once again.

Although the cost can be as high as $25,000, this may be worth it. High-level performance athletes who need to get back into sports play may find the overall costs savings well worth it. The shortened duration of painful symptoms with less time on the bench or in rehab offset the expense.

Likewise, anyone trying to keep a job, supporting self and/or a family may find the cost of restoring the joint surface acceptable.

Healthy cartilage cells called chondrocytes can be harvested from a patient, grown in a lab, and transplanted back into the knee. The entire process takes about four to six weeks.

Since the patient donates his or her own chondrocytes, the procedure is called autologous chondrocyte implantation (ACI).

ACI is a fairly new procedure. Long-term studies are not available yet. Some of the earlier studies do show positive results. After having an ACI, symptoms improve. The patients report less pain and better function.

Activities of daily living are restored and quality of motion returns to normal. ACI clearly helps many patients who are in pain but do not have enough knee damage to need a total knee replacement.

At least one study followed patients for four years with good results. The main problem after ACI involves hypertrophy or overgrowth of tissue. Additional surgery may be needed after ACI to remove the excess tissue and smooth the surface over.

This cocktail injection is the latest development in pain control after total knee replacement (TKR). Up until now, patient-controlled analgesia (PCA) has been the latest break through.

PCA allows the patient to push a button and release a small amount of narcotic (pain killer) into the blood stream. It’s set up on a timer so the person can’t take too much. PCA has allowed for better pain control and improved rehab.

The cocktail you are referring to is a combination of several drugs. This includes a numbing agent called Marcaine. It’s very similar to Novocaine. The cocktail also includes an antibiotic, steroid, and morphine (a narcotic drug).

The cocktail is injected in two parts. The first injection goes into the joint capsule before putting the new joint liner in place. The second injection goes into the periarticular (around the joint) soft tissues after the knee implant is in place. The synovium, muscles, and ligaments are injected.

According to the early results, this periarticular cocktail injection speeds up recovery. Patients are able to perform a straight leg raise sooner than when using the PCA. More patients go home sooner after the cocktail method of pain control.

If you did well with the PCA approach, it’s likely you’ll do even better with this new method.

Implants do come in various sizes as well as different shapes and designs. All three are important factors for good knee motion and function.

But it wasn’t always this way. In the beginning, there were only a few sizes. And there wasn’t any difference between implants used for the right knee versus the left knee.

Over time, researchers helped the manufacturers come up with better designs to fit the anatomy. They found ways to improve how the patella (knee cap) moves up and down over the joint. The implants came with parts that could be sized individually for each patient.

Then in the 1990s, improved materials came out on the market. At the same time, surgeons found better ways to do the surgery. They could use a smaller incision and cut much less of the muscles and soft tissues around the knee.

In the last few years, implant designs have improved for women. Scientists have used CT scans and computer analysis to map out the size, shape, and dimensions of the female knee. This has made it possible to prevent some of the more common problems with implants that are too large or too small.

This same research has also led to improvements for men. We know that a man’s knee is more of a rectangular shape than the woman’s knee. Shaping the implant to fit the contour of the patient’s bone has also helped improve the results.

Your surgeon will take all of these things into consideration when choosing and modifying the right implant for you. But don’t hesitate to ask this question. It’s always good to feel confident that you are getting exactly what you need.

Women often have painful symptoms from patellar tracking problems. The patella (knee cap) is designed to move up and down over the knee joint. The cartilage behind the knee actually fits a groove along the front of the knee. This anatomic design makes it possible for the patella to track up and down for smooth knee motion.

Anything that can pull the patella to one side or the other can change this tracking. The quadriceps muscle comes down the front of the thigh over the top and around the sides of the patella. The quadriceps muscle then attaches just below the knee joint along the front of the lower leg.

The alignment of the quadriceps muscle when measured from hip to knee is called the Q-angle. Many women have an increased Q-angle. This contributes to the patellar tracking problems already mentioned.

Joint replacement implant designs are just beginning to account for differences in knee size, shape, and dimensions between men and women. For the first time, the Q-angle is being considered. Until now, traditional implants were sex-neutral. There was a limited ability to adjust the implant to fit a Q-angle that wasn’t an average angle.

Should you ever need a knee joint replacement, your surgeon will carefully take all variables into consideration. Certain adjustments can be made during the operation to get a better fit with improved tracking. Over time, improved implant designs may even eliminate this step.

Ask your therapist what tool(s) he or she is going to use to track outcome measures (results). The phrase outcome measures is a standard one used in rehabilitation. There are many ways to assess results of treatment in rehab.

Sometimes a simple measurement like joint range of motion identifies progress. In other instances, impairments such as swelling or pain are graded on a scale from zero (none) to five (most) or zero to 10.

Surveys are often used to measure change in function, activities of daily living, or recreational status. For sports players, task-specific measures are often included. How quickly can the player pivot and move in a different direction? How difficult is it to do? Can the player kick a ball hard easily? How difficult is it to kneel or squat?

For older adults, a different set of questions may be used. For example, how difficult is it to get on and off a bus? How long does it take to walk 10 feet? Can the patient walk across uneven surfaces such as a slope?

Tracking your progress in a good idea. Taking baseline measurements before and post-intervention measurements after treatment is required in today’s evidence-based medicine.

Knee pain can have a wide range of different causes. It could be something as simple as chondromalacia, a softening of the cartilage behind the knee. Or it could be the result of osteoarthritis (OA).

Your doctor will be able to give you a better idea of the problem. A more complete history and description of the symptoms are needed. This will help your doctor identify the specific problem.

For example, arthritis between the patella (kneecap) and the femur (thighbone) can present with pain anywhere around or under the patella. Any activity that loads the joint can increase the painful symptoms. Going up and down stairs or hills, squatting, or kneeling are common activities that bring on this type of knee pain.

Walking on level ground causes less severe pain. Sitting with the knee straight out is the most comfortable position. The physician will ask you about a history of patellar dislocations. This may point to a misalignment of the kneecap. Imbalances of the muscles and other soft tissues around the knee can contribute to this cause of pain from uneven wear on the joint.

A physical exam with specific tests will be done. The results of this tesing helps the doctor decide what kind of further studies to order. For example, standing X-rays help show the joint space, position of the patella, and the presence of any bone spurs.

CT scans and MRIs are not routinely ordered. CT scans can help show how the patella is moving or tracking up and down over the femur. In the future, MRIs may be able to show the quality of the cartilage.

An excessive Q-angle can cause problems with tracking of the patella (kneecap). The Q-angle is the angle formed by the patellar tendon as it attaches to the knee joint. There is a groove underneath the patella that helps it slide up and down correctly over the femur (thighbone).

Anything that disrupts the normal tracking can wear down the cartilage and bone. An excessive Q-angle can have this effect. Realignment procedures can be done on the knee. A wedge- or pie-shaped piece of bone can be removed to shift the relationship between the tendon and the bone. This is called an osteotomy. The results are not always an improvement.

For severe pathology, a patellofemoral arthroplasty (PFA) can be done. This replaces the kneecap and applies a metal cap over the end of the femur where the patella glides up and down. This implant may not be the best answer if there are issues with alignment.

The surgeon may try to rebalance the soft tissues around the knee for more symmetrical tracking. If left uncorrected, the implant may not be able to function properly. For patients with excessive Q-angles, geometry of the implant (size, shape, and function) is important.

The implant must be able to allow some freedom of tracking. If the trochlear (inner) part of the implant is too narrow, the patella may catch on the edge causing a tracking problem. Newer implant designs have actually reduced the maltracking problems that patients used to have routinely.

The best way to find out what can be done about your situation is to seek the opinion of an experienced orthopedic surgeon. A physical exam, patient history, and some simple tests may be all that are needed to answer your questions more specifically.

Many clinics rely on questionnaires to help the patient and the therapist see the progress they are making. With the right kind of questions, improvement or the lack of progress can be seen quickly.

This helps move the patient along in the rehab process toward an earlier discharge whenever possible. It also helps point out problems or a need to change the direction or focus of treatment.

It can be time consuming and difficult to use a different survey for each patient. Some clinics try to adopt a standard tool that can be used with the majority of their patient base. In a sports rehab specialty clinic the questions are understandably not all appropriate for an older adult.

For example, questions about pivoting or side stepping while running may not apply at all. And questions about difficulty getting in and out of bed or up and down off the toilet may not be on the list but really much closer to where you’re at right now.

It probably won’t hurt anything to ask a few questions. This may help the clinic administrator take a closer look at the assessment tools they are using. And it might prove useful in making sure you are making the progress expected for your particular situation.

There has been a recent trend in the development of specialty hospitals. They first opened up to provide heart patients with specialty cardiac care. Bypass grafts and other cardiac procedures could be done in high volume and quickly.

All the staff in specialty centers are trained to do one task. All the equipment is for one procedure. This makes good economic sense for the doctors and owners of the specialized clinics and hospitals.

New specialty clinics are now focusing on hip and knee replacements. The same ideas apply. Communication among specialty staff is supposed to be better. The staff focuses on efficiency and organization. There may be less risk of hemorrhage, wound infection, and death reported in the specialized clinics.

But some experts think the specialty clinics do better because they have a healthier and wealthier group of patients. People from a higher income bracket are less likely to have diabetes and heart disease to compound problems after surgery.

Specialty hospitals are also less likely to use medical students, residents, or doctors-in-training to assist or perform the procedure. That means the patient benefits from the experience and expertise of a single surgeon doing many of the same operations.

According to a recent, very large study of Medicare patients, there is a 50 per cent lower risk of serious problems after joint replacement when done at a specialty orthopedic clinic.

This does not mean you can’t or won’t have an equally good outcome at a general hospital. The reasons for this difference between specialty hospitals and general hospitals isn’t clear yet. More study is needed before final decisions can be made about where, when, and how to have a total hip or knee replacement.

Osteochondral transplantation is one method of treating full-thickness cartilage tears in the knee. The usual location of these tears is at the end of the upper thigh bone where it connects to the knee.

The cartilage used can come from the patient or from a donor. It’s best if the surgeon can use the patient’s own tissue. This is called an autograft. But sometimes the tear is too large to harvest enough of the patient’s own cartilage cells. In that case, donor tissue is used.

Donor tissue is called allograft tissue. It comes from cadaver’s (bodies preserved after death). Family members are not called upon to find a tissue match and/or make a match.

Full-thickness cartilage tears called articular defects are becoming more and more common with increased sports participation. The area affected most often is the femoral condyle. This is the end of the thighbone where it meets the lower leg to form the knee joint.

Treatment depends on the size, location, and depth of the defect. The surgeon takes into account the stability and alignment of the joint when planning the treatment.

One option is cartilage implantation or cartilage transplantation. Sometimes the cartilage cells from the patient can be used. This is an allograft implantation. If the defect is too large or too deep, then an autograft transplantation is needed. This is tissue taken from a deceased donor.

There are many safety regulations involved in using donor tissue. Testing must be done to look for bacteria and viruses. The tissue must be carefully preserved and stored at very low temperatures. To maintain strict standards, much of donor tissue is thrown away before it’s even used.

Patient safety is always the number one concern in using donor tissue. Studies are being done to determine the ideal length of time that cartilage can be stored. At least one week is needed to carry out the minimum of tests. But if this timeframe could be extended, then more people might be able to benefit from available tissue.

You can be assured that after decades of transplants being done, the safety of this procedure has been improved. The biggest problem that occurs is graft failure. This can happen for many reasons. Sometimes the surgeon doesn’t know why the implant doesn’t take. In other cases, infection occurs.

Scientists hope that with a longer storage time, more testing can be done on the donated tissue. In this way patient safety is ensured and more people can be matched.

A stress reaction or stress fracture occurs when normal bone is exposed to repetitive loads. This type of injury usually occurs with vigorous weight-bearing activity such as jogging, running, or marching. Military soldiers, track and field athletes, and long distance runners seem to have the most bone stress injuries.

The symptoms are often pain in a specific area that gets worse with activity. The patient can point to the exact spot that hurts. The pain is relieved by rest but comes right back as soon as the person starts weight-bearing activities again.

Studies show that magnetic resonance imaging (MRI) is the most accurate way to diagnose bone stress injuries. X-rays do not show stress fractures when they are first developing. It may be six to eight weeks before a change in the bone is seen with an X-ray. MRIs are very sensitive and show both bone and soft tissue damage.

The anterior cruciate ligament, or ACL, is one of four ligaments that hold your knee together. If the ACL is torn, then you usually feel as if your knee is about to give out at you at any time, because there isn’t enough support.

There are three bones that make up your knee, and two major ligaments: the anterior cruciate ligament and the posterior cruciate ligament. These two ligaments stabilize the bones: the femur, which is the bone in the upper part of the leg, the knee cap, and the tibia, which is the leg in the lower part of the leg. The two ligaments make a cross shape and control the knee’s motion back and forth. The ACL provides up to 90 percent of the knee’s stability.

The ACL tear is a common injury and, while it happens most often in sports, it is the result of a sudden stop and twisting motion, or if the front or side of the knee receives a sudden blow. In sports, it’s often the result of an athlete running and coming to a quick stop and then changing direction at the same time. Pivoting on one leg, overextending the knee joint, or a hard landing from a jump can also cause the damage.

Many knee injuries happen because the person doesn’t do a thorough job of warming up and letting the muscles get ready for action. Stretching should always be done before exercising or playing sports. Strong leg muscles help take the burden off the knee. When someone is active, one way the knee gets injured is through sudden change in velocity or motion. Someone who is running in one directions, stops, and then turns is putting the knee at risk. Jumping and landing hard is also very hard on the knee.

Ensuring that you wear good, supporting shoes will help your knees at well. Be sure that you are wearing the proper shoe for the activity. Finally, some people who have already injured a knee will wear a brace on their doctor’s recommendation. If this has been advised, be sure to wear the brace as needed.

The history of how you hurt your knee will give your doctor a good idea of what the diagnosis will be. Certain movements, activities, and sports often cause specific types of knee injuries.

You’ll be examined and your doctor will want to know how well you can move your knee, whether you can walk on it, and how much pain you have. When ordering tests, there are several that your doctor can choose from and, of course, you may go for more than one to either refine the diagnosis or to confirm of it.

Most likely, the first test you will have is an x-ray to see if there is any problem with the bones. More specific testing can be done with computerized axial tomography (CT scan) or magnetic resonance imaging (MRI). Some doctors may ask for a bone scan to see that the bone itself is ok. Finally, the doctor may want to look directly into your knee with an arthroscope. To do an arthroscopy, the arthroscope – which has a camera attached to the end – is inserted into the knee through a small incision.

Articular cartilage of the knee is the smooth but tough covering over the end of the femur (thighbone). It protects the joint and the bone. At the same time, it allows for smooth gliding and movement of the knee joint.

Injury to the articular cartilage is fairly common in young, active adults (younger than 40 years old). It’s estimated that as many as 10 per cent of this group have such an injury. But articular cartilage injury can be silent with no symptoms at all for quite some time.

Pain, clicking, locking, and swelling of the knee are symptoms that occur when the injury is present over the load-bearing surface. In some cases, when the joint is bent to just the right angle, even minor injuries can cause symptoms.

There are several different grading systems for articular cartilage lesions. The International Cartilage Repair Society suggests a five-point grading scale from zero (normal) to four (severely abnormal).

The remaining grades (two, three, and four) describe progressively worse damage. Grade two is a tear that goes half way down through the depth of the cartilage. Grade three goes all the way through the cartilage but stops short of damaging the bone.

A grade four injury means the cartilage is torn clear through to the bone. A small piece of the bone attached to the torn cartilage is lifted away from the femur.

The tear may not get worse but the damage to the joint may progress. Without treatment, you may develop painful and limiting arthritis. Experts advise early diagnosis and treatment for these injuries.

Minor injuries can be repaired before pain and swelling reduce motion and function. It’s best not to wait for it to get worse but rather, restore the joint surface as quickly as possible.

Your orthopedic surgeon is the best person to advise you on this. Your age, general health, and severity of the osteoarthritis (OA) are factors to consider. Many experts recommend a management plan for this type of problem. Many methods are included such as weight loss and regular exercise. Studies show reduced knee pain with these two approaches.

Finding the right pain reliever or combination of drugs to control your pain should be part of the program. For most patients, this can be done without narcotics. Sometimes it takes a period of trial and error before you find the best choice for you.

If you haven’t been using a glucosamine and/or chondroitin product, ask your doctor about this option as well. These supplements can be purchased over the counter. They can be taken along with antiinflammatories and analgesics.

There are new pain control devices being investigated that might be helpful in the near future. For example, Deepwave, a form of deep tissue electrical stimulation has been shown effective with knee OA.

This type of electrical stimulation reaches deeper tissues compared to regular electrical stim. It blocks pain signals and releases endorphins and serotonin. These are chemicals that work together to reduce pain.

The results of the first pilot project using Deepwave have been reported. The device was very effective in reducing pain and stiffness. As a result, patients were able to increase function and activity.

You may have a tear in the articular cartilage of the knee. This is the fibrous layer of cartilage that covers the end of the femur (thighbone). The only way to know for sure is to have a physician examine you and order some imaging studies.

Weight-bearing X-rays with the knees straight will be taken. Then several other views with the knees bent 30 and 45 degrees are viewed. MRI is the best imaging test for this problem. The signals help identify where and how deep the full-thickness tear has occurred. The MRI also shows the condition of the bone underneath the cartilage.

Depending on the location and size of the tear, you may or may not have symptoms. Or you may have very mild pain and symptoms even when there is a serious tear. Some patients only notice pain when the knee is loaded at a specific range of motion. Symptoms of locking, catching, and clicking with motion are common.

If the tear or lesion is present within the weight-bearing axis, pain occurs only when the joint is loaded at a specific angle. This may be what you are experiencing. It’s best to have a physician examine you. Left untreated, these types of injuries can develop into arthritis.