FAQ Category: Knee

Anterior cruciate ligament (ACL) repairs are still done using either a patellar tendon graft or a hamstring tendon graft. Results have been equally good with both in terms of pain relief and knee stability. Just as many athletes return to their preinjury level of play with either method.

There is one major difference to be aware of. A five-year study comparing patellar to hamstring tendon graft repair showed a significant increase in osteoarthritis (OA) with the patellar tendon graft. Patients with patellar tendon ACL grafts had a narrower joint space and more bone spurs on that side.

Based on the results of this one study, you may want to stick with the hamstring tendon graft for both sides. Ask your surgeon about this. Graft choice may be a more important consideration in the big (long-term) picture than previously thought.

Anterior cruciate ligament (ACL) injuries are common knee problems. This is especially true for the active athlete. ACL repair is almost always needed to return to a preinjury level of sports.

Solitary ACL injuries are fairly rare. Most of the time, some of the surrounding soft tissues are also injured. This could be a torn ligament or damaged meniscus or joint cartilage. Sometimes the joint capsule has been affected, too.

Studies show that ACL-repairs have a better final result if all known damage is repaired at the same time. Just doing an ACL repair without taking care of the collateral damage has negative outcomes.

A recent study from Slovenia compared results of ACL repair using the two common graft techniques. They found that the type of graft made a difference. After five years, the patellar tendon group had much higher rates of arthritis compared to the hamstring tendon group.

The hamstring group had more meniscal problems. The conclusion of the authors was that damage to the meniscus along with ACL tear may not be as much of a problem as once thought. Choice of tendon graft seems more important.

Anterior cruciate ligament (ACL) repairs of the knee are usually done with a piece of tendon from the patellar tendon below the knee or from the hamstring tendon behind the knee. This donor graft may come from your own leg or from an outside donor.

Either way, healing is a step-by-step event. First the graft begins to die, a process called necrosis. This signals the body to send blood to the area to help it out. New cells arrive and new collagen tissue is deposited to form what’s called a matrix. Eventually the matrix is remodeled to remove any excess tissue and reshape it.

Grafts can fail to take if they don’t get enough blood supply. This can happen when there’s too much tension on the graft. Pressure from the bone can also contribute to this problem.

Keeping the leg immobile too long after surgery can have a negative effect. As the old saying goes, Motion is lotion. Keep in mind that not enough exercise or too much exercise can both be detrimental. Follow your rehab program carefully to avoid this problem.

Finally, good nutrition is always important for any injury or postoperative healing process. Getting plenty of fruits and vegetables and keeping up on hydration (drinking water or sports drinks with minimal sugars) is always advised. Avoid tobacco use as nicotine has a known delaying effect on wound healing.

Your surgeon will review any complications from the surgery and what can happen afterwards. From a recent update on failed ACL repairs, we can tell you the most common pitfalls after primary (first) ACL repairs.

Up to one-third of all ACL repairs result in stiffness with loss of joint motion. This can occur because of scarring inside the joint from being immobilized too long, infection, or for unknown reasons.

Loss of flexion isn’t as much of a problem as loss of knee extension. If you can’t straighten your knee all the way, you may end up limping when you walk. This is a real problem if you happen to be an athlete because it interferes with running as well.

Rehab is essential to regain muscle strength and motor control needed for normal motion and activity. If the muscles don’t fire at the right time, you may not be able to respond fast enough to sudden movements or stress on the joint. You could end up reinjurying the ACL repair.

Fortunately, failures of ACL repairs don’t happen very often. If you follow your surgeon’s instructions and complete your rehab program from start to finish, you will likely have a very good final outcome. Most people are able to return to their full preinjury level of activity, including recreational or competitive sports.

Replacing one compartment of the knee joint is called a unicompartmental knee arthroplasty (UKA). Most often it’s the inside (medial) half of the joint that wears down first and becomes arthritic.

There are several pros and cons to this operation. Operative and recovery time are less. The cost is less, too. But there are some concerns, too. Studies show the UKA doesn’t last as long as the TKR. Other studies show function is improved more with the UKA compared with the TKR.

There may be an increased need for revision if the one-sided implant comes loose or the other compartment wears out. Then the patient would need a total knee replacement (TKR) after all. Overall, the UKA has become more popular as surgical implants and techniques improve.

A recent analysis of the cost versus benefit of UKA and TKR for low-demand patients confirmed the usefulness of the UKA. Low-demand means the person is fairly inactive and unlikely to put much stress on the new implant. Your father may fall into this category.

If the UKA gets him back on his feet sooner he may become more active. Many older adults find that pain relief from the implant makes their daily activities so much easier. They weren’t looking for a game of tennis or to take up jogging again, anyway. Many elderly patients die of unrelated causes before the UKA ever wears out or needs revision.

You didn’t mention your age but since you are still working, we will assume you are younger than the average adult having a knee replacement. The peak age range for patients having total knee replacement (TKR) is 75 to 84 years old. Many patients having the unicompartmental knee arthroplasty (UKA) are younger than that.

Time in the operating room for a UKA is about an hour shorter than for a TKR. Recovery time is less for UKA, both in the immediate post-operative period and for rehab afterwards.

A recent study of outcomes suggests that patients experience about five weeks of disutility after a UKA. Disutility is defined as less than perfect health. This time period may vary depending on the age of the patient and general condition or fitness before the operation. Any complications such as infection or implant loosening can alter this estimate.

The demands of your job may make a difference as to how soon you can return to work. For example, manual laborers may need more time to rehab and build up enough strength for the required tasks compared to someone with a sedentary job at a desk. You may be able to return to your job before attaining perfect health.

Check with your surgeon for a more accurate idea. He or she may have some additional information to offer based on the type of implant being used and clinical examination of your condition.

Shoe insoles have been shown to work in patients with unilateral joint changes. This means only one side of the joint is wearing down. Most often patients have medial joint changes. This means the weight is unevenly placed on the inner edge of the joint.

A shoe insert, insole, or other similar device can help redistribute the weight on the foot up through the knee. Reducing the load on the inner edge of the joint has been shown to reduce painful symptoms. With decreased pain and improved walking, patients can be more active.

A recent study in Japan also showed that such a wedge helped reduce the dynamic load on the joint during walking. It’s not always possible to tell who will benefit from this type of treatment and who won’t. The Japanese study showed that overall function and quality of life were improved in patients with early, mild joint changes. Such changes were equal among men and women but did not occur with moderate to severe arthritis.

Whether or not this will work for you, may require a trial period. It’s not clear how much time is required before changes will occur or be noticed. The type of insole and time needed are both part of the trial and error.

Unicompartmental knee arthroplasty (UKA) has become very popular for patients with one-sided joint changes. Many people have medial joint changes. Such changes occur because of increased angles between the hip, knee, and ankle. Excessive angles can shift the weight toward the inner edge of the knee. Over time, the increased load wears down the joint on one side faster than the other.

If joint changes are caught early enough, you may be able to benefit from a simple shoe insole to off-load the joint. A plastic, silicon, leather, or rubber cup or wedge can be slipped inside the shoe. Some of these devices are designed to be placed under the shoe’s own insole. Others rest on top of the shoe’s insole and fit around your heel.

Lateral wedge insoles have been shown to help in cases of mild (grade one or two) osteoarthritis (OA). Ask your doctor if you are a good candidate for this kind of noninvasive treatment.

Patellofemoral pain syndrome (PFPS) occurs when the patella (kneecap) doesn’t track correctly up and down over the knee. In the normal, healthy knee, the patella follows a groove to guide it as the knee bends and straightens.

Any imbalance in muscle strength or timing can alter the normal biomechanics of the knee and especially the patella. The result can be knee pain and loss of function.

Recent studies have helped us see the importance of an exercise program for this problem. Hip and knee muscle strength are both important. For example, muscles in the hip control rotation of the femur (thigh bone) and the angle of the knee. Both of these effect how and when motion occurs at the knee.

Using muscle control and coordination to improve the bony alignment can help correct knee tracking. Improving patellar tracking can reduce symptoms of PFPS. Specific exercises are needed to make all this happen.

Usually a six- to eight-week program of rehab exercises is enough to get the patella back on target. Of course, everyone responds differently and may have varied results. Sometimes there are other factors affecting PFPS that must also be addressed.

A recent study done by athletic trainers and physical therapists suggest that a weight-bearing program of exercise can help with this problem. They showed that strengthening, stretching, and working on neuromuscular control can change the timing of quadriceps contraction. The result was decreased pain and increased function for patients with patellofemoral pain syndrome (PFPS).

It is suggested that you follow a home program supervised by a trained professional. Look for a licensed physical therapist or athletic trainer who has an understanding of this specific problem.

Expect a progressive program of exercises such as daily hamstring, quadriceps, and calf stretching. In the first week, you’ll also likely start with wall slides, heel raises, and lateral step-downs off a low step. Balance activities, mini-squats, and forward lunges will gradually be added. You may be given an elastic band to increase resistance of some exercises.

Over a period of six to eight weeks, you will build up to three sets of 10 repetitions for each exercise. Weekly monitoring may be all that’s required to advance your program.

It’s not clear yet how long such a program must be kept up for the best results. Some patients decide based on their symptoms, level of activity, and sports participation.

Different surgeons define a failed ACL repair in different ways. Failure rates range from 10 to 25 per cent depending on how the failure is defined.

Some experts use joint laxity (looseness) as the main indicator. Tests of joint side-to-side motion show an excess of motion. This test is called the pivot-shift test. There may be forward and back laxity measured by the anterior drawer test.

A special measuring tool called the KT-1000 Arthrometer may be used to test ligament laxity. The KT1000 gives an objective measure of the forward-to-back motions of the tibia (lower leg bone) relative to the femur (thigh bone).

The Arthrometer gives accurate assessment of the integrity of the ACL. More than a 5-millimeter difference between sides suggests ACL instability. If the patient’s knee gives way during daily activities or during sports or recreation, the joint is considered unstable and tested for ligament laxity.

Certainly a combination of all these tests can be used to assess ligamentous stability. A positive response to all three tests is a good sign that the ACL repair has failed and is not holding the joint stable.

Anterior cruciate ligament (ACL) repairs can be done using a piece of tendon from someplace else. Usually the donor graft comes from the patellar tendon below the knee or from the hamstrings muscle behind the knee. The hamstrings muscles has several tendons. The semitentinosus is the tendon of choice.

Many studies have been done to show that the hamstring tendon does regenerate (grow back) in most cases. There have been some studies to suggest that atrophy and shortening of the ST muscle belly occurs in some patients. When this happens, there is loss of strength when the leg is in a position of knee-flexion.

Patients get the best results when the ST grows back and reattaches below the knee joint. This gives it the right position to transmit forces from the ST to the tibia (lower leg one).

Recovery of full strength when the knee is bent is less likely if the tendon doesn’t regenerate and/or if the tendon reattaches above the knee. Only athletes who need strength when in a full squat position are affected. This includes judo athletes, gymnasts, and ballet dancers most often.

For the everday, average but active adult, you should expect full recovery of motion and function.

Many studies have been done to compare these two methods of anterior cruciate ligament (ACL) repair. The hamstring tendon repair has gained in popularity with surgeons because it is easy to harvest. Usually the semitendinosus (ST) portion of the hamstrings is the donor tendon.

With patellar-tendon grafts, there can be pain and loss of function when kneeling.There are fewer problems at the donor site after the operation when the ST tendon is used. A recent study highlighted one disadvantage to the ST donor site.

Loss of strength during deep knee flexion has been reported when using the ST tendon instead of the patellar tendon. Measurements of strength with the knee bent to 45- and 90-degrees showed a loss of torque (force) at 90 degrees (full squat position).

The strength deficit was only shown in patients whose ST tendon reattached above the knee joint or who did not have tendon regeneration seen on MRI. Most patients had full regeneration and full recovery.

Surgeons agree that not all ACL repairs that fail must be revised. Revision surgery is saved for patients with a chronically unstable and/or painful knee. If you have pain with everyday activities or you are unable to enjoy sports activities, then you may be a good candidate for revision surgery.

It’s not clear yet who are the best candidates for revision surgery. Studies are being done to identify risk factors that might suggest a revision operation is (or isn’t) going to help. These are called predictive factors of outcome.

About 10 per cent of revision cases also fail. According to a recent report from a Sports Injury Center in Rome, Italy, this may be because of errors in surgical technique.

Sometimes the tunnel drilled to thread the tendon graft through is too big. In other cases, the graft is attached in the wrong place and gets pinched during knee motion. The wrong graft tension or not attaching the graft properly can also result in failed surgery.

Until it’s clear who should have revision surgery for a failed primary (first) ACL repair, symptoms and function are the main factors used in making the decision to have a second operation.

Loss of knee extension is called a knee flexion contracture. It means your knee is stuck in a position of flexion and can’t straighten all the way. Without full knee extension, your ability to walk is affected. Not only does it take more energy to walk without full extension, but it slows you down!

Most surgeons would advise a total knee replacement. Preoperative casting or stretch-bracing have been suggested to reduce the knee flexion contracture. The idea is to restore as much motion as possible to make the surgery easier.

There are very few studies to investigate this idea. It’s likely the time it would take to gain a few degrees of motion wouldn’t be worth the extra pain and loss of daily function. Extension can be much more easily restored during surgery.

The surgeon will take the necessary steps to balance the soft tissues and remove any bone spurs affecting motion. Joint motion is checked and rechecked during the operation. Minor adjustments are made in bone structure, joint capsule, and tendon length until full motion is available.

When a surgeon replaces a joint, the condition of the soft tissues around the joint is always evaluated carefully. Muscles, ligaments, and joint capsule may all be contributing to the problem and can be corrected.

The surgeon will carefully take steps to restore full motion during the operation. Removing any and all bone spurs called osteophytes is important. Osteophytes can act as a bony block to the joint, preventing it from moving all the way. These bone spurs can also keep the soft tissues from moving smoothly and freely with the same result.

If removing the osteophytes still doesn’t restore your motion while in the operating room, then the surgeon can remove some of the bone at the bottom of the femur (thighbone). If this doesn’t gain the needed motion, then one of several other steps can be taken.

First, the joint capsule may be cut or released. Then the gastrocnemius (calf muscle) may be released. Finally, a hamstring tenotomy can be performed. A tenotomy is the surgical cutting or division of a tendon.

Most often these last steps aren’t needed. Just removing the osteophytes and balancing the soft tissues around the knee is enough to restore your motion. It may take awhile, but with rehab you should be able to resume walking normally after your knee replacement.

You shouldn’t have to make this decision alone. The team of health care professionals working with her can give you advice and counsel. The physical therapists (PT) will be measuring her strength, coordination, balance, and motion. These are the skills needed for everyday activities of walking, climbing stairs, and getting around safely.

The occupational therapist (OT) will know when she is ready to resume her daily activities of daily independently in her own home setting. Usually the PT and/or the OT make a home visit and assess her needs based on her living situation. If there is no PT or OT, then a nurse or social worker may be the one to do this.

For example, is her home on one level? Or does she have to manage stairs to get in and out of the house? Are there grab bars in the bathroom to help her manage toileting and bathing? Is the laundry room accessible? What other adaptive aids or equipment are needed for her to bathe, cook, clean, and manage her daily tasks?

The PT can give your mother several tests of physical function to help guide this decision. For example, the Timed Up & Go Test (TUGT) measures how fast a person can get up from a chair, walk three meters, turn and return to sit in the chair. Or patients are given the Six-Minute Walk Test. They walk as far as they can safely in six-minutes.

There are standard measures of how fast a person should be able to do these tasks to show they can live safely by themselves. Your mother’s score will be compared to those standards to give you both an idea of how well she is doing.

You may be referring to a new surgical method of cartilage repair called microfracture technique. The drilling of tiny holes through the cartilage and into the bone releases blood from the bone marrow. The blood forms clots in the holes and creates a scaffold for healing cartilage to build upon.

Research so far shows that putting weight on the healing cartilage delays healing. Loading the joint must be avoided for up to two months to foster maturation of the fibrous tissue.

On the other hand, motion of the healing cartilage is very important. Patients are put on a machine called continuous passive motion (CPM). The leg is strapped into this device and it automatically bends and straightens the knee over and over.

It appears that this kind of constant motion helps improve nutrition and metabolic activity at the cellular level. Somehow the CPM helps the knee form the right kind of cartilage. Hyaline cartilage is needed for a good, strong repair. Too much fibrous cartilage leaves the defect soft and more likely to fail.

It’s likely that no serious damage will occur if you forget and put your leg down once or twice. For the best results, follow your surgeon’s advice carefully.

There is still a fair amount of debate over this question. Unfortunately for young athletes, all we have to go on are adult and animal studies. The standard treatment in adults with a combined ACL-MCL injury is nonoperative treatment for the MCL tear (bracing). Arthroscopic reconstruction of the ACL is done later.

This order of treatment comes from the results of studies showing better motion and strength when treatment is done in stages compared to patients who had both repairs done at once. On the other hand, some surgeons advise early ACL repair. They argue that when the ACL is weak or damaged, then the MCL can’t heal as quickly.

Most of the studies are done on adults. Children and adolescents may have a different response to the timing of treatment. There aren’t very many studies in this age group to help guide treatment strategy.

A recent report from Children’s Hospital of Philadelphia (CHOP) showed equal results between two groups of adolescent athletes. Group 1 had an isolated ACL tear. Group 2 had both a torn MCL and ACL. Group 1 had ACL reconstruction. Group 2 wore a special brace for the MCL for six weeks before having the ACL repaired.

Results of the two groups were the same. All athletes were able to go back to their previous level of sports play after surgery and aggressive rehab. A similar study needs to be done with MCL and ACL repair at the same time. For now, we don’t have results for treatment done at the same time.

Combined MCL and ACL tears in adolescent athletes are on the rise with increased sports participation. These type of injuries are much more common in adult athletes. Treatment is usually with bracing for the MCL tear and surgery for the ACL tear.

A recent study from Children’s Hospital of Philadelphia (CHOP) reported on 12 cases of MCL-ACL tears in children ages 11 to 15. Hinged-bracing was used on the knee for four to six weeks. Bracing was used to treat the MCL injury. Arthroscopic repair of the ACL was done after that with a follow-up rehab program.

Patients were able to go back to their preinjury level of sports participation. All had pain free range of motion and near normal strength. Recovery from surgery and rehab doesn’t allow the athlete to finish the current season. Most are able to return within one to two years.