FAQ Category: Knee

Stress fractures may be more appropriately named stress reactions. The bone develops tiny cracks from repetitive stress. The stress or load is at a level lower than occurs when the single load trauma that causes a clear break through the bone.

Stress fractures occur when there’s an imbalance between how much bone is broken down and how much is replaced. This cycle of bone resorption and replacement is a normal process. But it can get side tracked when repetitive stress or load from running or jumping disrupt bone function.

Activities must be modified (changed) in order to relieve pain and allow for normal healing. Sometimes proper shoe wear and a change in the training program are needed. Nutrition and running surface should also be evaluated as possible factors in healing and recovery (and to prevent future fractures).

Symptom severity can help guide treatment. Severe pain is often treated with no weight-bearing or partial weight-bearing using crutches. A pneumatic leg brace has been shown to decrease pain and speed up the recovery process.

Return to full activity may occur within a matter of weeks. But if healing is delayed, then recovery can take four to six months or more (up to a year). Once a stress fracture has occurred, the athlete must guard against future recurrences.

Proper training schedules, avoiding sudden increases in training intensity, and wearing the correct shoes are important. Likewise, adequate rest and good nutrition are key factors in recovery time.

Shin splints refers to pain and swelling of the lower leg. Sometimes this condition is also called chronic exertional compartment syndrome (CECS). The lower leg is divided into four sections or compartments.

Each compartment contains muscles, blood vessels, and a major nerve. The compartments are surrounded by stiff connective tissue called fascia. This helps keep the sections separate.

As the muscles are used, they expand in size and volume. In fact, muscle fibers can swell up to 20 times larger during and after exercise than when in a resting state. If the inelastic compartment doesn’t respond to the expansion, pain and loss of blood supply can occur. Athletes such as dancer or runners use muscle activity that repetitively stresses one or more of the compartments.

Compartment syndrome can be a very serious condition. Loss of blood to the area can lead to death of muscle tissue. In extreme cases, gangrene can even occur. Once the diagnosis is made, stopping the aggravating activities is required. Physical therapy can be a successful conservative approach.

If symptoms aren’t improved after six to 12 weeks of therapy, then surgery may be needed. Some experts claim that only surgery can cure compartment syndrome. The fascia is split open to allow muscular movement and expansion inside the compartment. This procedure is called a fasciectomy. In some cases, the fascia may be removed (fasciotomy) or a combination of the two procedures may be needed.

Computerized technology is all over medical and surgical procedures throughout the developed world. In the case of joint replacements, computer programs have been used for a while to help place the proper angles in the joints as they are being inserted into the patient.

Currently, computer-navigated total knee arthroplasty (replacement) is used to help in improving the accuracy of the joint position. The position and orientation of the replacement and the patient’s bones are measured and assessed before and during the surgery.

That being said, the technology is not foolproof and surgeons and technicians still need to find ways to improve their use of the technology to limit errors even more.

Many times, orthopedic surgery – bone surgery – is compared to carpentry. When doing a joint replacement, the surgeon has to cut out the joint that is to be replaced and insert the prosthesis, the replacement.

To attach the replacement, there are pieces of hardware that are specific to each type of prosthesis and the type of bone to which it is to be attached. There is also surgical cement that is used to stabilize the replacements.

Most of the time, these pieces of hardware hold the prosthesis as they are intended to do, but there are situations where the hardware can fail or break, causing pain and mobility problems. When this happens, revision surgery is usually needed.

Surgery can force athletes into a period of reduced activity, which leads to a decline in overall fitness and strength. This is a major concern for the injured athlete.

Programs to maintain muscular and cardiopulmonary conditioning are important. If you are working with a physical therapist for knee rehab, you can ask for guidance with a fitness program as well.

Two of the most commonly used exercise tools are the stationary bicycle and the arm cycle. The arm cycle works both arms at the same time. The stationary bike is more of a one-legged exercise for those who have had knee or leg surgery. While the healthy leg pedals, the recovering leg can be propped on a chair next to the bike. The uninvolved leg can be strapped to the bike pedal for one-legged cycling.

One study comparing these two forms of exercise found they were equally effective in achieving aerobic conditioning. The arm cycle was perceived as more rigorous, which might suit your need to feel like you’ve had a good workout.

But if you want an easier form of exercise that still builds cardiovascular fitness, then one-legged cycling may be just what you are looking for. Of course, you can still use free weights or elastic tubing to maintain upper body strength during your course of recovery.

The posterior cruciate ligament (PCL) is one of two ligaments that criss-cross inside the knee. Both of these ligaments have different functions to allow joint movement while stabilizing the knee.

Without the PCL, the tibia (lower leg bone) doesn’t move normally. It slides back too far when the knee is straight. And it doesn’t glide forward as it should when the knee is bending. More recent studies also show the PCL helps hold the knee steady side-to-side as well.

Many people are able to function just fine without the PCL for everyday activities. But the risk of re-injury or another injury is raised when patients participate in sports or other vigorous activities.

And long-term studies show that over time, abnormal shifting and sliding of the tibia leads to degenerative arthritis of the joint. This happens because the places where the bones come together and move against each other have changed. When the joint surfaces don’t match up properly, uneven wear occurs.

You can always get a second opinion. But experts agree that early reconstruction is the treatment of choice for PCL injuries. There’s no guarantee, but the hope is that by restoring stability, degenerative joint changes leading to a painful arthritic condition can be prevented.

The surgery to repair a torn anterior cruciate ligament or ACL is usually done as a day surgery.

The surgeon makes a small incision in the knee to be able to see and access the torn ligament. This is usually done with an arthroscope, a small instrument with a camera on one end. Through other small incisions, the surgeon can use instruments to do the repair. Using these instruments, the surgeon removes the old ligament and drills a hole (tunnel) to fasten down the new ligament.

The new ligament may be taken from the patient him or herself from a tendon. This is then fastened into place where the old legament was.

Diagnosing ligamentous damage to the knee can be very difficult. There are many tests to choose from. Some are more sensitive than others. Applying them correctly is important. If the patient can’t relax the hamstrings (muscles behind the thigh and knee), then the test results aren’t always clear.

The KT-1000 and KT-2000 arthrometer devices are used to test specifically for insufficiency of the anterior cruciate ligament (ACL). They give objective, accurate, and reliable results.

The patient’s knee is bent to a 30-degree angle and placed on a special supportive wedge. The arthrometer is strapped to the calf. Proper positioning of the leg and foot is very important for this test.

A forward (anterior) force is applied on the tibia (lower leg bone). In fact, the test is conducted using three different amounts of force. If the tibia moves too far forward against the femur (thigh bone), the test is positive for an ACL tear.

The normal or uninvolved side can be tested first for comparison. Malposition of the arthrometer by as little as one centimeter can make a difference. However, it eliminates many of the other errors that can be made when using a hands-on testing method.

The knee is a very complex joint held together by many ligaments and connective tissue surrounding the joint capsule and tendons. The specific injury to the joint can be very difficult to discern at first. There are several reasons for this.

First of all, if the patient has any amount of swelling or pain, the joint stiffens up. Muscle tension and guarding occurring around the joint prevent movement. This can make it seem as though the joint is still very stable, when in fact, it’s not.

Second, sometimes ligaments are damaged but not ruptured. Further episodes of unexpected forces can result in further injury. So what appears as a strain or sprain can progress to a full rupture with continued use.

And for some injuries, more than one soft tissue structure is disrupted. If the correct tests aren’t applied accurately, the examiner may see the knee as normal when it’s not. This is a false-negative test.

Most of the tests used to assess the knee joint are hands-on, applied by the examiner. Correct technique and interpretation are needed for the diagnosis. The examiner can be misled if proper positioning isn’t used. If the muscles around the joint are contracting during the test, instability may be masked or hidden.

A dashboard injury refers to damage of the posterior cruciate ligament (PCL) inside the knee. When a sudden impact from behind occurs, the passenger’s knees are pushed forward into the dashboard. The force of the knees against the dash can cause the tibia (lower leg bone) to shift back far enough to rupture the PCL.

We’ve known for a long time that the main function of the PCL is to keep the tibia from sliding too far back on the femur (thighbone). But more recent studies have shown us that the PCL has some other functions as well. It also keeps the tibia from shifting side-to-side during knee motion. And it prevents too much rotation of the tibia.

Without an intact PCL, the joint shifts change the contact and pressure points. This can result in the type of early degenerative changes you are experiencing. Treatment today is with early reconstruction in the hope of preventing this from happening.

If you haven’t already done so, see an orthopedic surgeon for an evaluation. Find out what are your treatment options. You are probably a good candidate for a rehab program.

The physical therapist will prescribe a program to strengthen the muscles around the knee joint. In the absence of an intact ligament, strong muscles can help support the joint during motion and possibly hold off the negative effects of a torn PCL. Other exercises can help re-tune receptors in the joint that tell you where the joint is and what motion is occurring. This can help prevent further traumatic injuries of the joint and may improve motion.

Orthopedic surgeons are always trying to improve the design of artificial joint replacements. Over the past 40 years, many different implant designs have been tried and tested. Some of these designs have worked better than others.

There isn’t a specific designer prosthesis that we know of, but you may have heard about gender-specific implants. This is a prosthesis that is made just for a man or a woman. The size of the implant is slightly different to adjust for the anatomical differences between males and females. For example, men have larger femurs (thigh bone) where the implant is inserted.

The width of the bone is also different between the sexes. Women tend to have a narrower side-to-side width at the bottom of the femur. This is the part that forms the upper half of the knee joint. A gender-specific implant is made to accomodate this difference.

Manufacturers of joint implants start with an average size and then build implants that are slightly larger or smaller than average. The gender-specific implants do this too but try to match male and female normal anatomy. The goal is to improve durability and function.

Studies are very limited on the actual benefits of these designer implants. There are no studies showing that gender-specific implants work better than the traditional prostheses. Orthopedic surgeons say that implants already come in many sizes that will fit almost anyone’s anatomy.

The American Academy of Orthopaedic Surgeons (AAOS) recently did a review of studies comparing men and women with total knee replacements (TKRs). They asked two questions: 1) Who has a higher failure rate after traditional TKR: men or women? 2) Does having a specific knee replacement for women increase the rate of success?

They found that even with many of the anatomic differences between men and women, the results of traditional TKR was not different between the two sexes. Range of motion and scores on tests of knee function were similar. Some studies reported that women have lower rates of failure from wear and tear over time. The need for implant removal or revision was equal between men and women.

There were no studies of gender-specific TKRs. This is an area for future research. A gender-specific total knee replacement implant is a prosthesis that is designed either for a male or a female. The size of the implant is slightly different. It is built to make adjustments for the differences in sizes and anatomy of the bones between genders.

It’s possible the results in your family are just by chance. But there could be an anatomical trait that lends itself to poorer results compared with men. Other factors include type of implant, surgical technique used, and surgeon’s experience. There may have been differences in the rehab program used with the women compared with the men. Attitude and compliance may also have affected the outcomes.

The procedure you are having is called autologous chondrocyte implantation (ACI). Autologous refers to the fact that the surgeon is harvesting your own tissue. Chondrocyte is the medical term for cartilage cell.

ACI is one of three new methods used to regenerate joint tissue. It can be used when the defect is 2.5 cm2 or less in size. Some studies show that even larger defects in patients with more symptoms are less likely to have good growth of normal hyaline-like tissue. Hyaline tissue is the type of cartilage that lines the inside of the knee joint.

Previous surgery and patients with older defects are less likely to regenerate normal joint (hyaline) cartilage. But these factors do not necessarily exclude you from having the procedure.

Your surgeon will have a better idea how to advise you after taking a look at the damaged area. This is usually done during the arthroscopic exam. The exam may be done before or as part of the ACI harvesting procedure.

The kneecap or patella is designed to fit in the middle over the femur (thigh bone). This forms the patellofemoral joint. During normal motion, the patella moves up and down along a groove in the femur. This central position and tracking is optimal for joint motion and function.

If the patella is slightly off-center in either direction, then there is an increased risk of uneven load and force on the patellofemoral joint. Over time and with repetitive motion, patellofemoral pain (PFP) may develop.

Women seem to be at increased risk for this problem. Even in females without PFP, the patella is often off center laterally (away from the midline). But it’s likely there are other factors as well. A laterally displaced patella doesn’t automatically mean the athlete will have knee pain or other knee problems.

The optimal position for the patella (kneecap) is in the middle of the knee. Kneecaps that point inward or outward move unevenly over the femur (thigh bone). The articular cartilage along the under surface of the patella can get scratched and torn when there’s maltracking of the patella.

X-rays and MRIs aren’t really necessary since the condition is obvious to the naked eye. These tests may help identify the degree of displacement. They may show the presence of any tilt in the patella. But they do not necessarily contribute anything extra to the diagnosis.

A full exam of the individual may be more helpful. Any structural or postural factors contributing to the problem can be identified and addressed. Muscle weakness, lack of coordination, or altered motor control can also be observed and treated.

Your daughter may only need a support in her shoe to change the angle of her knee. This can change the forces that are transmitted through the leg. Or she may need a remedial strengthening program to overcome muscle imbalances. In some cases, neuromuscular control is altered (muscles fire too soon, too late, or not enough). A rehab program can also address this problem.

Both of these methods of joint regeneration are under close study. There’s not enough evidence to support one over the other yet. The lack of consistency in results among studies may be a matter of patient selection, specific surgical technique used, or some other factor. Further study is needed to sort out all the variables that can affect success or failure.

New biologic methods are being tested to find better ways to stabilize and grow chondrocytes (cartilage cells). If these are successful, chondrocyte implantation may become the preferred treatment for cartilage defects. Microfracture is more likely to create fibrous (tough) scar tisue. Over time, this tissue breaks down and painful symptoms return.

What the joint really needs is the formation of hyaline or hyaline-like cartilage. Hyaline cartilage is durable and holds up under repeated compressive loads placed on the joint.

Recovery may be slower after the chondrocyte implantation when open surgery is used. But the differences in clinical outcome disappear six months after surgery. If the regenerated chondrocytes hold up better over time, the slower pace of physical recovery may be worth the wait.

Injury of the anterior cruciate ligament (ACL) is very common, especially among athletes. Most surgeons agree that surgery is needed to repair the damage. Whether or not to have the operation is a decision each patient must make with the advice of his or her surgeon.

Some things to consider along the way include your activity level, knee stability, and the mechanism of injury. Let’s look at each one of these a little more closely.

Surgery is recommended most often for high-level athletes who want to return to their preinjury level of sports activity. Early intervention prevents further damage to the knee and reduces the overall recovery period.

Knee stability is next. Giving-way of the knee is a sign of ACL deficiency and knee instability. A stable joint is one that doesn’t give way or buckle. The joint must remain stable when stressed or required to respond to rapidly changing loads during activities.

Patients who suffer an ACL injury during noncontact sports are most likely to need surgery. In such an injury, the person was not involved in a collision with another player or object. Instead, the ligament tore as a result of an action such as pivoting, jumping, or cutting.

This suggests the internal load exceeded the tensile strength of the ligament. Muscular strength, coordination, and control around the joint were not enough to prevent the rupture.

If you are not involved in sports or other high-stress activities, and your knee isn’t buckling or giving-way, then you may not need surgery. A good rehab program of strengthening and neuromuscular control may be all that’s needed.

But if you had a noncontact injury and you intend to get back as quickly as possible, then reconstruction may be the best choice.

Females do appear to be at greater risk for anterior cruciate ligament (ACL) injuries than men. Many studies have been done to find out why this is happening.

Here’s what we know so far. First of all, more and more females of all ages are participating in sports. The very nature of athletic involvement increases anyone’s risk of injury regardless of gender. Overall, there are more ACL injuries among men but there are also more men in competitive sports.

Some studies have looked at the size, shape, and position of the female pelvis in relation to the knee joint as a potential factor in ACL injuries. Altered stresses, load, and force on the joint from these anatomical features may play a role in ACL injuries among women.

Others are investigating the role of neuromuscular control. This refers to how well the muscles around the knee compensate for any intrinsic (already present) deficiency of the ACL.

When comparing males to females, men generate greater muscular stiffness around the knee joint. They recruit muscles in a different pattern than women. It may be the case that women’s natural movement doesn’t allow for the intense athleticism required in today’s competitive sports.

The best evidence available shows that improving strength, motor control, and proprioception (sense of joint position) may be the best prevention policy available. Training should include all three of these key components. Whether or not doing so will always prevent injury remains to be seen.

A reflex hammer is used to check how well your nerves react to the stimulus of being tapped. Your doctor knows where the nerve is closest to the skin in the elbow and knee. By taking the point of the reflex hammer and tapping it, your arm or leg should react in a certain way.

If the doctor taps lightly, he or she will not expect a wild or intense reaction but some reaction is expected. Likewise, if the tap is harder, the reaction would be expected to be a bit more intense.

Sometimes, it can be hard for the reflex test to be done if the patient is concentrating on it, so it wouldn’t be unusual for the doctor to find a way to distract the patient. The best result is done if the patient isn’t paying attention to the tapping.

Small areas of damage to the cartilage in the knee joint have a limited ability to fill in with fibrocartilage. Complete and normal healing is not likely. Areas of full-thickness lesions larger than two centimeters by two centimeters (two centimeters squared) are not likely to heal without treatment.

Treatment today involves several techniques designed to stimulate bone marrow to make a clot. With multiple fibrin clots, a small defect in the cartilage can fill in and replace normal cartilage with similar cartilage.

One of those techniques is called microfracture. Another is autologous chondrocyte implantation (ACI). The microfracture procedure is done in one step. Tiny holes are drilled around and through the cartilage defect. Blood and fat cells from the bone marrow migrate into the area of the lesion and begin a healing process.

ACI is a two-stage operation. Healthy cartilage is harvested from the patient and placed in a special solution. After several hours, the cells are washed and mixed with a small amount of the patient’s blood serum. This is allowed to sit in the lab for several weeks while the cells multiply.

When the cells have increased 20 to 30 times, then the new chondrocytes are injected into the lesion. Special steps are taken to prepare the damaged area first before implantation.

These techniques are fairly new. No long-term studies have been done to show what happens years after the surgery is done. Short- to mid-term studies show good results. Some surgeons prefer the microfracture approach to ACI because of the difference in cost, technical difficulty, and extra surgery of ACI.