News Category: Knee

If you’ve had surgery to repair a torn anterior cruciate ligament (ACL) in the knee, will you be safe from future knee injury? That’s the subject of this study by military doctors. They reviewed the records of 6,576 active duty army soldiers who had an ACL injury.

All soldiers were followed for up to nine years. Slightly more than half (58 percent) had surgery to repair the ACL while 42 percent did not. The researchers looked at how many in each group had another knee injury later. In this way they could compare the results of ACL repair with conservative treatment. They also recorded how much time went by between the first and second injuries.

Here’s what they found:

Surgeons in Japan are using a new arthroscopic surgery to treat osteoarthritic (OA) knees. It’s called posteromedial release (PMR). Surgeons use a long needle with a tiny TV camera on the end (an arthroscope) to go inside the joint. The meniscus, ligament, and joint capsule are taken out from the inside (medial edge) of the joint.

Patients in this study all had OA with medial knee joint pain. Motion was limited and the knee could no longer straighten all the way. This is called a knee flexion contracture. The surgeons describe their technique to perform this operation.

Long-term results of the treatment are reported. Patient pain levels, function, and satisfaction were used as measures of success. X-rays and MRIs were also used to assess the results. Patients were followed for up to five years.

Most of the patients had decreased pain and increased function. Three-fourths of the patients were happy with the results. Only six patients had continued knee pain. They ended up getting a total knee replacement (TKR) anywhere from one to two and a half years later.

The authors concluded that the results of PMR aren’t as good as a TKR. PMR is still a good option for some patients. After PMR patients are much better than before surgery, and the results last at least two (or more) years. The bone is preserved and the patient gets improved motion. Patients can still have a TKR later.

Knee replacements are becoming more and more common. Even patients with severe deformity can have a joint replacement. But it can mean some fancy footwork on the part of the surgeon. In this study, doctors report on a new, simpler method used to replace the knee joint in knees with severe valgus deformity.

Valgus knee deformity is a medical way to describe knock-knees. With the valgus knee much of the load from the body weight presses down on the inner (medial) side of the knee. Bone and soft tissue changes occur making surgery to replace the joint more difficult.

The new soft tissue release for valgus knees presented in this study has good long-term results. It’s called an inside-out release.

Forty-two patients had this operation and were followed for at least five years. The authors describe step-by-step how the release is done. They say it is easier to align the bones while keeping the ligaments in balance. The tools and positions used during the operation are discussed.

X-rays were used to see knee joint alignment before and after the surgery. The goal was to reduce pain and improve motion and function by balancing the soft tissues while replacing the joint. Patients improved in their ability to walk and climb stairs. The changes lasted over time and only three patients needed further surgery.

The authors conclude that patients with severe valgus deformity can have a knee joint replacement. The inside-out release makes it possible to restore both joint alignment and
soft tissue balance.

Consider these facts. Americans 85 years old and older are the fastest growing age group in the United States. Americans of Hispanic or Latino descent are the largest minority group in the United States. The number of Black Americans is rising and expected to keep increasing. Black and Hispanic adults are less likely to have a joint replacement when needed compared to white adults.

In this study researchers looked at uninsured minority patients. The goal was to find out if these patients have more serious arthritis than insured white adults at the time of joint replacement. Over 700 patients who had a hip or knee replacement were included in the study.

The patients were divided into four groups: 1) Hispanic white, 2) Non-hispanic white, 3) Hispanic black, and 4) Non-hispanic black. Slightly more than half identified themselves as Hispanic. Pain, function, and quality of life were measured for each patient.

This is the first study to look at the link between race and ethnicity and type of insurance with health status at the time of joint replacement surgery. They found race and ethnicity was a stronger predictor of outcome than insurance status. The type of insurance didn’t seem to have as much bearing on patient function before surgery. Patients without coverage of any kind had the lowest function and poorest health before joint replacement.

Blacks and hispanics have more pain and less function than whites at the time of their joint replacement. The authors aren’t sure why this happens. There may be cultural or language barriers. Or there may be genetic factors leading to more severe disease in blacks.

More studies are needed to answer these questions. From this study here’s what we know that non-hispanic black patients have more advanced disease when they have a joint replacement done compared to others. And black males are the least likely to seek joint replacement for arthritis.

Fact: The number of hip and joint replacements in these groups is 1/2 million each year and expected to increase in future years.

So, you’ve had an anterior cruciate ligament (ACL) injury. And you’ve had surgery to repair the damage. Should you wear a brace during sports activities after surgery or not? This is the topic of a study done on 100 ACL patients from three US military service academies.

Cadets and midshipmen were divided into two groups: with and without bracing. All patients had a simple ACL tear without damage to the cartilage, bone, or other ligaments. Everyone had the same surgery within the first eight weeks after the injury. Everyone followed the same rehab program after surgery. The brace users wore the brace for one year during activities with cutting, pivoting, or jumping motions.

Patients were followed for at least two years. Results were measured by looking at motion, strength, and return to full activity. X-rays were taken and any further injuries recorded. The study showed no difference between the two groups. Some patients felt more confident while wearing the brace but the number of re-injuries between the groups was the same.

Bracing the knee during activity after ACL repair is common. The authors of this study have shown it may not be needed for young, active patients. They think better methods of surgery and faster rehab have improved ACL results. This study supports the findings of other research that shows that braces have no effect on outcome after ACL repair.

Patients in the United Kingdom, the United States, and Australia took part in this study on total knee replacements (TKRs). The researchers were interested in comparing how patients measure up before and after TKR. They wanted to see results from multiple centers in different countries.

Each patient was assessed before and after the operation. Follow-up measures were taken at three, 12, and 24 months after the TKR. Physical function, mental health, and general health were measured. A physical exam was carried out. The exam looked at walking ability, stair climbing, balance, motion, and strength.

Researchers found that patients who had more pain and less motion before surgery had the worst results afterwards. Patients in the United Kingdom had much worse results than patients in the United States or Australia.

The authors suggest differences in health care systems account for this finding. Patients in the United Kingdom were older and reported more pain than patients from other countries. They often had to wait up to a year to get on the surgery list. It was even longer before they had the operation. In the United Kingdom, patients are taken on a first-come, first-served basis rather than on severity of pain and loss of function.

Women in every country were worse off before surgery compared to men. Men and women had equal results after TKR. Patients with other health problems had less function after the operation. The authors think this is because they couldn’t do the full rehab program. Poor mental health was also a predictor of poor outcome.

The authors conclude that knowing risk factors for a poor outcome after TKR can help doctors plan ahead. Patients with worse pain and function should have the TKR as early as possible. Patients with a possible poor outcome can be counseled ahead of time about what to expect. Pain and mental and physical function before surgery are the best predictors of results afterwards.

Not much is known about kneeling for patients with a total knee replacement (TKR). Is it safe to kneel? Will the joint implant wear out sooner if you kneel? Does the new joint work the same way when kneeling as when squatting or climbing stairs?

These are questions researchers at the University of Vermont are trying to answer. X-rays were taken in three positions for 20 patients with TKRs who could kneel and stand easily. The researchers looked for contact points for two types of knee implants in two kneeling positions. The results were compared to the contact points while standing with the knee straight.

The authors report that patients who had trouble kneeling were more likely to report back pain or scar pain as the reason. They found that kneeling with 90 degrees of flexion was the same as deep flexion during squatting and climbing stairs. There was a little more movement in one of the two implants. Neither type was in danger of dislocating.

After TKR, many patients want to resume activities that require kneeling. This report offers some information to help give patients guidelines for kneeling. It’s not clear if plastic replacement parts will wear out sooner with kneeling. For now it looks safe for patients to kneel carefully on occasion.

A torn anterior cruciate ligament (ACL) can be repaired using a piece of the hamstring tendon (the graft). The missing tendon grows back. But does the hamstring have its full strength and function after recovery? This study measures how much hamstring tendon tissue grows back. The study compares how much tissues grows back to the strength of the hamstring muscle.

Twenty-eight patients were followed for at least two years. All patients had a hamstring tendon graft to repair a torn ACL. The graft was taken from the same leg as the ACL injury. MRIs were taken of both knees for comparison. Hamstring strength was measured in three positions.

The results showed that tissue regrowth occurred so that the tendons were the same size on both sides. Strength was still less on the graft side. In the prone position (face down) using full knee flexion, the hamstring had only half the strength of the healthy hamstring.

The authors report that even if the tendon grows back at the graft site, normal strength is not regained. The position affected the most is deep flexion. Gymnasts performing on floor exercises and on the balance beam use this position. Wrestlers and judo athletes also have trouble using a hooking action that requires full knee flexion when lying on the mat.

More study is needed to find out what keeps the hamstring from regaining full strength. There may be more than one factor involved. It may depend on which hamstring tendon is used. Or the healthy leg may get stronger as the patient favors the leg that was weakened by surgery. The result could be added hamstring weakness from more than just the tissue graft.

Anterior cruciate ligament (ACL) tears are a common knee injury in the United States. Without surgery to repair the damage, most athletes can’t remain active. The damage is fixed by replacing the torn ligament with a piece from some other ligament. The graft is usually taken from either the quadriceps or the hamstring muscle.

Getting the right graft tension is a challenge. At first the graft tissue loses strength while the body is accepting it. If the graft is set too tight it may lose its blood supply. Healing will be delayed. If it’s too loose the result can be a loose knee with too much motion.

Most grafts will stretch to some extent after surgery. The perfect amount of graft tension hasn’t been decided yet. In this study, doctors used a special machine to measure the sliding motion of the knee joint. They tested this movement, called joint laxity, right before surgery. They also measured it during the operation and again six months later.

There was no link between joint laxity right after the operation and joint laxity six months later. In all cases the graft loosened up after six months. But the doctors couldn’t use the amount of laxity at the time of the operation to tell how much laxity patients would have six months later.

The authors conclude that joint laxity after ACL repair is based on more than one factor. It’s likely that the patient’s overall joint laxity makes a difference. So does the rehab program, how the bones line up to form the knee, and the healing process itself.

If you have arthritis in both knees and need both joints replaced, should you have them done one at a time or both at the same time? This debate goes on in medical circles. Some doctors recommend both at the same time because it saves money and time. Others do only one at a time for safety and because of the increased rate of problems.

A doctor from the University of Tennessee reviewed studies done so far on this issue. In this article he presents the reported advantages and disadvantages of having both knees done at the same time (bilateral replacement). On the positive side:

Doctors are using much smaller incisions to replace hip joints. Now they are trying it out on knee joint replacements. But many questions remain about this method. In this review, Dr. Vail looks at the latest developments in total knee replacements (TKRs) and asks questions that must be answered in coming years.

One of the new ideas in the world of TKRs is the minimal incision used to replace the joint. Smaller incisions mean less blood loss, a shorter time under anesthesia, and faster rehab. But how much is a faster recovery worth? Is it worth the risk of a failed implant or chronic pain? Dr. Vail points out the less invasive operation must have the same good outcome as a full incision, or it’s not worth doing.

New technology is also changing the way TKRs are done. Computer-assisted TKRs will be more accurate, but at what cost? Will the patient have good function? Will the implant last just as long? New total knee devices will likely be on the market soon. Combined with new methods and new technology, they will change the way TKRs are done in the near future.

Little by little, total knee replacements (TKRs) have changed for the better. In this report, two surgeons from Canada review the changes made in the knee cap or patella during TKR.

Early in the history of TKR surgery, the patella was ignored. But then knee pain in more than half the patients got the surgeons’ attention. Arthritis causes changes in the joint and also on the back of the patella. Damage to the patella must be taken care of when the joint is replaced. This is called patellar resurfacing.

At first a flat piece of metal was put on the bottom of the femur (thighbone) where it moves against the patella. This was called a femoral flange. Patients still had pain in front of the knee over the patella. Later the flange was curved, and a button was added to the back of the patella. The button helps the patella track up and down against the flange.

Is patellar resurfacing always needed? That is the question these researchers asked. They reviewed published reports and compared patients who had their patella resurfaced with those who didn’t.

The authors found that patellar resurfacing seems like a good idea for most TKRs. Patients younger than 60 may not need it. Patellar resurfacing may also be unnecessary if the cartilage on the patella is in good shape. The same is true if the patella is tracking well.

Is there a best choice of graft material to repair a torn anterior cruciate ligament (ACL)? This is a question doctors have asked and studied for the last 40 years. As time and technology march on, new ideas are researched and tested every year. In this review, the most recent data on the ideal graft choice is presented.

The authors say the perfect graft would meet three goals:

Most meniscal (knee cartilage) tears occur when the person is standing, putting weight on the leg. However, tests for meniscal tears are all done in a non-weightbearing position. Until now. The Ege’s test is a new way to assess the knee meniscus under weightbearing conditions. In this study, the Ege’s test was compared to two other standard tests for meniscal tears. The two tests are McMurray’s test and joint line tenderness.

Ege’s test is done while the patient is standing. The knees are straight and the feet are eight to 10 inches apart. To test the medial meniscus, the patient squats with the feet and legs turned out fully, then stands up slowly. The lateral meniscus is tested by turning the feet and knees in as far as possible.

A positive test occurs when pain or click is felt, and maybe even heard, when the patient bends the knees about 90 degrees.

The knees of 150 patients with symptoms of meniscal injury were tested using the three tests. Afterwards the knees were examined arthroscopically. Anyone who tested positive and also had a torn meniscus during arthroscopic exam had a true positive result.

Here’s what the examiners found:

Doctors at the Hospital for Joint Diseases in New York City are studying ways to reduce pain after arthroscopic surgery of the knee. Arthroscopic surgery is less invasive than open surgery. That means less pain and faster recovery. Even so, there is still pain after knee arthroscopy. Some patients don’t get enough help with pain control early in recovery.

In this study, doctors used rofecoxib (Vioxx®, an anti-inflammatory medicine) given one time before the operation. The hope was to reduce pain after surgery. They also wanted to help patients avoid taking narcotic drugs. They thought patients might even have a faster recovery after the operation.

They were right on all counts. According to the authors, patients getting Vioxx had much lower pain scores after the operation. Pain was less when measured eight and 24 hours later. This is important, because patients are usually home by this time. They don’t have a nurse or doctor to help with the pain.

Records showed there was also much less use of narcotic drugs during the first 24 hours. This is good because narcotics cause nausea and vomiting in many patients. The authors say that patients can get back to daily activities faster when they don’t use narcotics.

This report shows that a pre-emptive strike against pain works well for arthroscopic surgery. The idea is to gain control of pain before the patient leaves the hospital.

In this article, Dr. Reid and his associates report on the use of arthroscopy for total knee replacement. This way of doing the operation is called minimally invasive surgery total knee arthroplasty or MIS-TKA. An incision of less than five inches is used. The kneecap is moved out of the way, but it isn’t turned over like it would be in the more traditional open-incision operation.

The authors review when the MIS-TKA is best used and when it should be avoided. Obese patients and anyone with extreme knee deformities shouldn’t have the MIS-TKA. They also point out the benefits of the MIS-TKA. There is less blood loss and less trauma to the soft tissues around the knee. The muscles reportedly recover faster.

For doctors thinking about using the MIS-TKA to replace knee joints, there are tips on the incision, using an assistant, and positioning the patient. Special surgical instruments must be used for this operation. The author reviews where and how to make cuts in the soft tissues and bone during the operation. The surgeon must use a fine touch throughout the operation and make changes to suit each individual patient.

It makes sense that the more often you do something, the better you get at it. This is also true for doctors who perform operations to replace knee joints. With this in mind, Medicare is even starting to regionalize total hip and knee replacements. This means all joint replacements would be done at select centers around the United States.

The results of this study may support this decision. Researchers at half a dozen major medical centers looked at Medicare claims for patients who had a total knee replacement (TKR). They found that patients had better results when managed by doctors who do a high volume of TKRs. Their patients had fewer problems after the operation.

All patients in the study were over 65 years of age. They were in good health and only had one knee replaced at the time of the study. Everyone was followed for at least 90 days. Five specific problems were tracked: death, heart attack, infection, pneumonia, and blood clot to the lungs. They also looked at the type of hospital (urban or rural) and how many years the doctor had been practicing.

The authors found that the death rate is 30 percent lower in hospitals where TKRs are done routinely. The risk of heart attack and lung clots was also lower in these high volume hospitals. Complications for any medical problem were lower in high-volume hospitals. Results showed that number of years in practice were not as important as the number of TKRs done each year.

The authors conclude that patients should be told about treatment options. High-volume centers may be a good idea, but more research is needed. Long-term results must be studied before advising that all TKRs should be done at high volume centers.

This study showed that a single injection of a nerve-blocking agent can be used for pain control after a total knee replacement (TKR). The femoral nerve block (FNB) is given when the patient is anesthetized for the operation. The femoral nerve is blocked with a loss of sensation to the front and inner part of the knee. The effects last 12 to 16 hours.

There were two groups in this study. All patients were getting a TKR. The first group had anesthesia and a FNB. The second group had anesthesia and a fake nerve block (only saline was injected).

During the first 24 hours after the operation, patients with the FNB (Group A) asked for less painkillers than patients who didn’t get the nerve block (Group B). Group A also used less morphine during their stay in the hospital.

No other differences were seen between the two groups. Both groups had the same results in rehab and stayed in the hospital about the same number of days. The authors conclude that pain after a TKR can be managed with a single-injection FNB. The added cost is very small, and the gains are large.

After an anterior cruciate ligament (ACL) repair, some patients have trouble getting their full quadriceps muscle strength back. This study checked whether the width of the tendon used to replace the torn ligament is linked with muscle weakness after ACL repair.

ACL repair can be done by taking a piece of the quadriceps tendon and using it to replace the damaged ACL. Doctors measured the width of patellar tendons used in 540 patients. They measured quadriceps muscle strength before and after the ACL repair.

The researchers thought it was likely that patients with small patellar tendons and a weak quadriceps muscle wouldn’t be able to get their full quadriceps strength back. In the short run that’s exactly what they found. Patients with large tendons had better strength in the first three months after surgery.

By the end of two years, the tendon size didn’t make a difference in muscle strength. Patients with good muscle strength before the operation had good postoperative strength as well. The authors also reported the following findings:

Gender and maturation are two key factors in sports success. In this study, knee motion and motor control of middle-school and high school athletes were compared. All athletes were soccer or basketball players. Males were compared to females.

Landing from a jump was the activity studied. Three-dimensional knee motion was measured in a laboratory. The study included 100 girls and 81 boys. All were on a school sports team. None had a previous knee injury. Knee motion between boys and girls when landing a jump was the same before the children hit puberty. After puberty, girls had much more inward knee motion.

Strength and coordination didn’t increase in girls after a growth spurt like they did in boys. In fact, girls showed a decrease in muscle control from early to late puberty. The opposite is true for boys. They gained greater control as they matured.

Girls have a much higher rate of knee injuries than boys of the same age in the same sport. This study shows that girls land jumps differently from boys as they mature. The authors think girls lose coordination and control when these skills don’t keep up with bone growth.

The changes in joint position and force of muscle contraction make a difference when landing from a jump. These changes may account for the increased rate of anterior cruciate ligament (ACL) injuries in female athletes.