Introduction

Plica syndrome occurs when an otherwise normal structure in the knee becomes a source of knee pain due to injury or overuse.

Plica is a term used to describe a fold in the lining of the knee joint. Imagine the inner lining of the knee joint as nothing more than a sleeve of tissue. This sleeve of tissue is made up of synovial tissue, a thin, slippery material that lines all joints. The synovial sleeve of tissue has folds of material that allow movement of the bones of the joint without restriction.

Four plica synovial folds are found in the knee, but only one seems to cause trouble. This structure is called the medial plica. The medial plica attaches to the lower end of the kneecap and runs sideways to attach to the lower end of the thighbone at the side of the knee joint closest to the other knee.

Causes

A plica causes problems when it is irritated. Over time the plica can be irritated by certain exercises, repetitive motions, or kneeling. Activities that repeatedly bend and straighten the knee, such as running, biking, or use of a stair-climbing machine, can irritate the medial plica and cause plica syndrome.

If the knee is injured, the plica and the synovial tissue around the plica can swell and become painful. The initial injury may lead to scarring and thickening of the plica tissue later. The thickened, scarred plica fold may be more likely to cause problems later.

Symptoms

The primary symptom of plica syndrome is pain. There may also be a snapping sensation along the inside of the knee as the knee is bent, due to the rubbing of the thickened plica over the edge of the thighbone. If the plica has become severely irritated, the knee may become swollen. Pain from plica syndrome usually occurs when the knee is straightened from a flexed or bent position to a straight position.

Diagnosis

History and Physical Exam

Diagnosis begins with a history and physical exam. The examination will try to determine where the pain is located and whether or not the band of tissue can be felt. X-rays will not show the plica. X-rays are mainly useful to determine if other conditions are present if there is not a clear-cut diagnosis.

Radiological Tests

If there is uncertainty in the diagnosis or if other injuries are suspected, an MRI may be suggested. The MRI (magnetic resonance imaging) uses magnetic waves to show the soft tissues of the body. This test does not require any needles, X-rays or special dye and is painless. A CAT scan may also be used to see whether the plica has become thickened. Most cases of plica syndrome will not require special tests such as the MRI or CAT scan. A plica band can not always be seen on a MRI or CAT scan.

Diagnostic Tests

If the history and physical examination strongly suggest that a plica syndrome is present, arthroscopy may be suggested to confirm the diagnosis and treat the problem at the same time. Arthroscopy is an operation that involves inserting a small fiber-optic TV camera into the knee joint, allowing the orthopedic surgeon to look at the structures inside the knee to determine whether the plica is inflamed.

Treatment

Most people with plica syndrome get better without surgery. The primary treatment goal is to reduce inflammation. This may require limiting activities like running, biking, or using the stair-climbing machine.

Conservative Treatment

Most people with plica syndrome get better without surgery. The primary treatment goal is to reduce inflammation. This may require limiting activities like running, biking, or using the stair-climbing machine.

Surgery

If conservative treatments fail, surgery may be suggested. Usually, an arthroscope is inserted into the knee joint through one-quarter inch incisions. Once the plica is located, small instruments are inserted through another one-quarter inch incision to cut away the plica tissue and remove the structure. The area where the plica is removed heals back with scar tissue.

Rehabilitation

Following surgery, you will be referred to a physical therapist. Your first few rehabilitation sessions are designed to ease pain and swelling and help you begin gentle knee motion and thigh tightening exercises. Patients rarely need to use crutches after this kind of surgery.

As symptoms of swelling and pain are controlled, the focus of exercise is to get the quadriceps muscle moving again. Patients usually start with isometric exercises to tighten the front thigh muscle, advancing to straight-leg lifts. Muscle stimulation may be needed at first if the quadriceps muscle is sluggish. This technique uses electrical current passed though electrodes placed on the skin over the muscle.

As the program evolves, more challenging exercises are chosen. Patients do exercises that mimic familiar activities like squatting down, lunging forward, and going up or down steps. These exercises are designed to help keep pressure off the kneecap while getting a challenging workout for the leg muscles. Your therapist will work with you to make sure you are not having extra pain in your knee during the exercises. You may be shown stretches for the soft tissues along the edge of the kneecap as well as muscle stretches for the hamstrings, quadriceps, and calf muscles.

The therapist’s goal is to help patients keep their pain under control, make sure they aren’t putting too much weight on the injury, and improve quadriceps muscle strength and knee range of motion. When patients are well underway, their regular visits to the therapist’s office will end. The therapist will continue to be a resource, but patients will be in charge of doing their exercises as part of an ongoing home program.

Anatomy

The patella, or kneecap, is the moveable bone on the front of the knee. The patella is wrapped inside a tendon connecting the large muscles on the front of the thigh and the quadriceps muscles, to the lower leg bone. This tendon is called the quadriceps tendon above the patella and the patellar tendon below the patella.

The quadriceps mechanism, made up of the patella and tendon, allows you to straighten out the knee. The patella acts like a fulcrum to increase the force of the quadriceps muscle. The underside of the patella is covered with articular cartilage, the smooth, slippery covering found on joint surfaces. This covering helps the patella glide in a groove made by the thighbone, or femur called the patellofemoral grove. Together the patella and the groove in the femur are called the patellofemoral mechanism.

Causes

Problems commonly develop when the patella suffers wear and tear. The underlying cartilage begins to degenerate. Degeneration may develop as part of the aging process. The patellofemoral joint is usually affected as part of osteoarthritis of the knee.

One of the more common causes of knee pain is a problem with the way the patella moves through the patellofemoral groove. If part of this muscle is weak a muscle imbalance can occur. When this happens, the pull of the quadriceps muscle may cause the patella to shift to the outside. This, in turn, causes more pressure on one side of the articular cartilage than the other. In time, this pressure can damage the articular cartilage.

Another type of imbalance may exist due to differences in how the bones of the knee are shaped. Some people are born with a greater than normal angle where the femur and the tibia (shinbone) come together at the knee joint. Women tend to have a greater angle than men. The patella sits at the center of this angle within the femoral groove. When the quadriceps muscle contracts, the angle in the knee straightens, pushing the patella to the outside of the knee. In cases where this angle is increased, the patella tends to shift outward with greater pressure. As the patella slides through the femoral groove, this places more pressure on one side than the other, leading to damage to the underlying articular cartilage.

In some cases one side of the patellofemoral groove may be smaller than normal. This may cause the patella to actually slip out of the groove, causing a patellar dislocation. This is not only painful, but can cause degeneration of the patellofemoral joint if dislocation repeatedly happens.

Symptoms

If you have patellofemoral problems, you may feel like the patella is slipping. This is thought to be a reflex response to pain and not because there is any instability in the knee.

Sometimes you may have pain around the front part of the knee or along the edges of the kneecap. These symptoms may be related to the way the patella lines up in the femoral groove. Symptoms of patellar pain, however, can happen even when the patella appears to be lined up properly.

In other cases you may notice a dull pain in the knee that isn’t centered in any one spot. Typically, if you have patellofemoral problems you may experience pain when walking down stairs or hills. Keeping the knee bent for long periods, such as sitting in a car or movie theater, may also cause pain. The knee may also grind, or you may hear a crunching sound when you squat or go up and down stairs.

If there is a considerable amount of wear and tear, popping or clicking may be felt when the knee is bent. This happens when the uneven surfaces of the underside of the patella and the femoral groove rub against one another. The knee may swell with heavy use and become stiff and tight. This is usually due to fluid accumulating inside the knee joint, sometimes called “water on the knee.”

Diagnosis

Diagnosis begins with a complete history of your knee problem followed by an examination of the knee and the patella. X-rays may be ordered on the initial visit to your doctor. An X-ray can help determine if the patella is properly aligned in the patellofemoral groove. The X-ray may show arthritis between the patella and thighbone, especially when the problems have been present for a considerable amount of time.

Diagnosing problems with the patella can be confusing, so other tests, such as magnetic resonance imaging (MRI), may be suggested. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body.

This machine creates pictures that look like slices of the knee. Usually, this test is done to look for injuries, such as tears in the menisci or ligaments of the knee. Recent advances in the quality of MRI scans have enabled doctors to see the articular cartilage on the scan and determine if it is damaged. This test does not require any needles or special dye and is painless.

In some cases, arthroscopy may be used. Arthroscopy is an operation that involves placing a tube with a small fiber-optic TV camera into the knee joint, allowing the orthopedic surgeon to look at the structures inside the joint directly. The arthroscope allows your doctor to see the condition of the articular cartilage on the back of your patella. The vast majority of patellofemoral problems are diagnosed without resorting to surgery, and arthroscopy is usually reserved to treat the problems identified by other means.

Treatment

Treatment begins by decreasing the inflammation in the knee. Rest and anti-inflammatory medications, such as aspirin or ibuprofen, may be suggested by your physician, especially when the problem is due to overuse.

Physical therapy can help in the early stages by decreasing pain and inflammation. Your physical therapist may suggest the use of ice massage and ultrasound to limit pain and swelling. You may also be directed to use a brace or tape the patella to help reduce pain. As the pain and inflammation become controlled, your physical therapist can provide several exercise options to help correct problems with flexibility, strength, foot or knee alignment, and muscle balance in the knee.

Surgery

If these measures fail to improve your condition, surgery may be suggested. Arthroscopy is sometimes useful in the treatment of patellofemoral problems of the knee. Looking directly at the articular cartilage surfaces of the patella and the patellofemoral groove is the most accurate way of determining how much wear and tear there is in these areas. Your physician can also watch as the patella moves through the groove, and may be able to decide whether or not the patella is moving normally.

If there are areas of articular cartilage damage behind the patella that are creating a rough surface, special tools can be used by the surgeon to smooth the surface and reduce your pain. This procedure is sometimes referred to as “shaving” the patella. In more advanced cases of patellar arthritis, doctors may operate to repair or restore the damaged cartilage.

The type of surgery needed for articular cartilage is based on the size, type, and location of the damage. Along with surgical treatment to fix the cartilage, other procedures may also be done to help align the patella so less pressure is placed on the healing cartilage.

If your patella problems appear to be caused by a misalignment problem, a procedure called a lateral release may be suggested. This procedure is done to allow the patella to shift back to a normal position and relieve pressure on the articular cartilage. In this operation, the tight ligaments on the outside (lateral side) of the patella are cut, or released, to allow the patella to slide more towards the center of the femoral groove. These ligaments eventually heal with scar tissue filling the gap created by surgery.

For problems of repeated patellar dislocations or severe patellar malalignment, the doctor may also need to realign the quadriceps mechanism. In addition to the lateral release, the tendons on the inside edge of the knee (the medial side) may have to be tightened.

If the malalignment is severe, the bony attachment of the patellar tendon may also have to be shifted to a new spot on the tibia bone. Doctors can change the way the tendon pulls the patella through the groove in the femur by surgically removing a section of bone where the patellar tendon attaches on the tibia. This section of bone is then reattached on the tibia closer to the other knee.

Usually, the bone is reattached onto the tibia using screws. This procedure shifts the patella to the inside the knee. Once the surgery heals, the patella should track better within the center of the patellar groove, spreading the pressure equally on the articular cartilage.

Rehabilitation

Many doctors will have their patients participate in formal physical therapy after knee surgery for patellofemoral problems. Patients undergoing a patellar shaving usually begin rehabilitation right away. More involved surgeries for patellar realignment or restorative procedures for the articular cartilage require a delay before going to therapy.

The first few physical therapy treatments are designed to help control the pain and swelling from the surgery. The physical therapist will choose exercises to help improve knee motion and to get the quadriceps muscles toned and active again. Muscle stimulation, using electrodes over the quadriceps muscle, may be needed at first to get the muscle moving again.

As the program evolves, more challenging exercises are chosen to safely advance the knee’s strength and function. The key is to get the soft tissues in balance through safe stretching and gradual strengthening.

The physical therapist’s goal is to help you keep your pain under control, ensure you place only a safe amount of weight on the healing knee, and improve your strength and range of motion. When you are well underway, regular visits to the therapist’s office will end. The therapist will continue to be a resource, but you will be in charge of doing your exercises as part of an ongoing home program.

Introduction

Osteochondritis dissecans (OCD) is a problem that affects the knee. The disease behaves much differently in children and for this reason is given a separate name, juvenile osteochondritis dissecans (JOCD). The condition affects the end of the big bone of the thigh commonly known as the femur.

These disorders are uncommon and most often occur in young athletes. Children as young as nine or ten years old can develop JOCD. Any adult can develop OCD, with most patients ranging in age from early adulthood to age fifty.

OCD and JOCD cause the same kind of damage to the knee, but they are separate diseases. In the child who is still growing, the problem is much more likely to heal itself. In the adult, the bones are not growing. For this reason, the treatment and recovery after OCD and JOCD can be very different.

A joint surface damaged by OCD doesn’t heal naturally. Even with surgery, OCD usually leads to future joint problems, including degenerative arthritis and osteoarthritis.

Anatomy

Most cases of OCD and JOCD affect the femoral condyles of the knee. The femoral condyle is the part of the knee made up of the rounded end of the thighbone, or femur. Each knee has two femoral condyles, the medial femoral condyle (on the inside of the knee) and the lateral femoral condyle (on the outside). Like most joint surfaces, the femoral condyles are covered in articular cartilage. Articular cartilage is a smooth, slick covering that allows the bones of a joint to slide smoothly against one another.

The problem occurs where the cartilage of the knee attaches to the bone underneath. The area of bone just under the cartilage surface is injured leading to damage to the blood vessels of the bone. Without blood flow, the area of damaged bone actually dies. This area of dead bone can be seen on an X-ray and is sometimes referred to as the osteochondritis lesion.

OCD and JOCD usually affect the part of the joint holding most of the body’s weight. The lesions are under constant stress and don’t get time to heal. Also, the lesions cause pain and problems when walking and putting weight on the knee. It is more common for the lesions to occur on the medial femoral condyle, because the inside of the knee bears more weight.

Causes

JOCD

Many doctors think that JOCD is caused by repeated stress to the bone. Most young people with JOCD have been involved in competitive sports since they were very young. A heavy schedule of training and competing can stress the femur in a way that leads to JOCD. In some cases, other muscle or bone problems can cause extra stress and contribute to JOCD.

OCD

Sometimes JOCD is not treated or does not heal completely. When this happens, JOCD develops into OCD. OCD can occur any time from early adulthood on, but most patients are adults under age fifty. Cases of OCD first diagnosed in early adulthood probably began as JOCD. When a person gets OCD later in life, it is probably a new problem.

Doctors aren’t sure what causes OCD. There is less of a link between strenuous repetitive use and OCD. Many people who develop OCD don’t have any particular risk factors.

Because OCD leads to damage to the surface of the joint, the condition can lead to problems with bone degeneration and osteoarthritis. The damage to the joint surface affects the way the joint works. Over time this imbalance can lead to abnormal wear and tear on the joint and can cause degenerative arthritis and osteoarthritis.

Symptoms

OCD and JOCD cause the same symptoms usually starting out mild and growing worse with time. Both problems usually start with a mild aching pain. Moving the knee becomes painful, and it may be swollen and sore to the touch. Eventually, there is too much pain to put full weight on that knee. These symptoms are fairly common in athletes. They are similar to the symptoms of sprains, strains, and other knee problems.

As the condition becomes worse, the area of bone that is affected may collapse causing a notch to form in the smooth joint surface. The cartilage over this dead section of bone (the lesion) may become damaged. This can cause a snapping or catching feeling as the knee joint moves across the notched area. In some cases, the dead area of bone may actually become detached from the rest of the femur forming what is called a loose body. This loose body may float around inside of the knee joint. The knee may catch or lock when moved if the loose body gets in the way.

Diagnosis

History and Physical Exam

Your doctor will ask many questions about your medical history. You will be asked about your current symptoms and about other knee or joint problems you have had in the past. Your doctor will then examine the painful knee by feeling it and moving it. You may be asked to walk, move, or stretch your knee. This may hurt, but it is important that your doctor knows exactly where and when your knee hurts.

Radiological Tests

Your doctor will probably order an X-ray of your knee. Most OCD lesions will show up on an X-ray of the knee. If not, your doctor may suggest a bone scan. A bone scan is the best way to see the lesions in the very early stages.

A bone scan involves injecting a special type of dye into the blood stream and then taking pictures of the bones with a special camera. This camera is similar to a Geiger counter and can pick up very small amounts of radiation. The injected dye is a very weak radioactive chemical. It attaches itself to areas of bone that are undergoing rapid changes–such as a healing fracture. The camera provides a picture that is used by your doctor to see OCD lesions in the very early stages.

Your doctor may want to do other imaging tests, such as magnetic resonance imaging (MRI). The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. With this machine, doctors are able to create pictures that look like slices of the knee and see the anatomy, and any injuries, very clearly. These tests may help determine the extent of damage from OCD and JOCD, and they also help rule out other problems.

Treatment

Many cases of JOCD can be completely healed with careful treatment. OCD will probably never completely heal, but it can be treated. There are two methods of treating JOCD: conservative treatment to help the lesions heal, and surgery. Surgery is usually the only effective treatment for OCD.

Non-Surgical Treatment

Conservative treatments help in about half the cases of JOCD. The goal is to help the lesions heal before growth stops in the thighbone. Even if imaging tests show that growth has already stopped, it is usually worth trying conservative treatment. When conservative treatment works, the knee seems as good as new, and the JOCD doesn’t seem to lead to arthritis.

Conservative treatment of JOCD can take from ten to eighteen months. During that time, it is crucial to stop activities that cause pain to the knee. This means stopping exercise and sports. It may require using crutches or wearing a cast for a couple of months when the knee is symptomatic. As the knee becomes less symptomatic, non-weight-bearing exercise can be started. The exercises should be done carefully and should not cause any pain. Patients often work with physical therapists to develop an exercise program.

Regular bone scans will be taken throughout the treatment to track how well the lesions are healing and to see if surgery is eventually needed. Even in JOCD, surgery may eventually be required. When the lesion has become so bad that it detaches totally or partially from the bone, conservative treatment will not work. Even with treatment, some patients continue to have symptoms or their bone scans show signs that the damage is getting worse.

Some patients who are too near the end of bone growth may not benefit with conservative treatment. When these problems develop, your surgeon may suggest surgery.

Surgery

If the lesion becomes totally or partially detached, surgery is needed to remove the loose body or to fix it in place. Your doctor will need to gather information about your knee and your problem before surgery. This may require additional bone scans, X-rays, or MRIs. Your doctor may also use an arthroscope, a tiny camera inserted into the knee, to look at your knee before surgery.

These tests are important because your doctor needs to know the exact location and the size of the lesion to determine what kind of surgery will work best. In some cases, your doctor will be able to use the arthroscope to do the surgery. If the arthroscope can be used, the procedure requires smaller incisions than for an open surgery, which may reduce the time needed before the knee can be moved and exercised.

Open surgery is needed when your doctor can’t get a picture of the entire lesion, when it is unclear how the fragment would best fit into the bone, or when it would be too difficult to replace the fragment using the arthroscope. Open surgery usually requires larger incisions than arthroscopic surgery to allow the surgeon to see into the knee and perform the operation.

If the loose bone fragment is in a weight-bearing area of your bone, your doctor will try to reattach it if at all possible. Your doctor may use tiny metal pins or screws to hold the fragment in place. This sometimes proves difficult. The damaged fragment often doesn’t fit perfectly into the bone anymore. And the bone around the fragment may have changed requiring your doctor to rebuild it.

Despite the difficulties, reattaching the fragment generally results in much better knee function than removing it. Your knee will not be as good as new, but a careful plan of exercise and follow-up care can help you use your knee again without pain.

In rare cases, the lesion must be removed from a weight-bearing area. Your doctor may try to fill in the hole using an allograft. An allograft is an actual transplant of bone and cartilage from a donor into your knee. The bone is usually obtained from a bone and tissue bank.

In this case, bone material is transplanted into the hole left in the bone. Allografts have risks, including graft rejection and infection. But they can be very successful in returning function to the knee.

Rehabilitation

If you have surgery, your doctor may have you use a continuous passive motion (CPM) machine afterwards to help the knee begin to move and to alleviate joint stiffness. A CPM machine gently moves your joint for you.

With the exception of arthroscopic removal of a loose body, patients are instructed to avoid putting too much weight on their foot when standing or walking for up to six weeks. This gives the area time to heal. Weight bearing is usually restricted for up to four months after an allograft.

Patients are strongly advised to follow the recommendations about how much weight is safe. They may require a walker or pair of crutches for up to six weeks to avoid putting too much pressure on the joint when they are up and about.

Many doctors will have their patients take part in formal physical therapy after knee surgery for osteochondritis lesions. The first few physical therapy treatments are designed to help control the pain and swelling from the surgery. Physical therapists will also work with patients to make sure they are only putting a safe amount of weight on the affected leg.

Exercises are chosen to help improve knee motion and to get the muscles toned and active again. At first, emphasis is placed on exercising the knee in positions and movements that don’t strain the healing part of the cartilage. As the program evolves, more challenging exercises are chosen to safely advance the knee’s strength and function.

Ideally, patients will be able to resume their previous lifestyle activities. Some patients may be encouraged to modify their activity choices, especially if an allograft was used.

The therapist’s goal is to help patients keep their pain under control, ensure safe weight bearing, and improve their strength and range of motion. When patients are well underway, regular visits to the therapist’s office will end. The therapist will continue to be a resource, but patients will be in charge of doing their exercises as part of an ongoing home program.

Introduction

Injuries to the articular cartilage in the knee joint are common. These injuries, called lesions, often show up as tears or “pot holes” in the surface of the cartilage. If a tear goes all the way through the cartilage, doctors call it a full-thickness lesion. When this happens, surgery is usually recommended.

Anatomy

Articular cartilage covers the ends of bones. It has a smooth, slippery surface allowing the bones of the knee joint to slide over each other without rubbing. This slick surface is designed to minimize pressure and friction as you move.

Cartilage tissues are not supplied with nerves. However, holes or rough spots in the cartilage can cause the joint to become inflamed and painful. If the injury, or lesion, is large enough, the bone below the cartilage loses protection. Pressure and strain on this unprotected portion of the bone can also become a source of pain.

Doctors classify damage to knee cartilage using a grading scale from one to four.

Grade One – the cartilage has a soft spot.

Grade Two – minor tears visible in the surface of the cartilage.

Grade Three – lesions have deep crevices.

Grade Four – the cartilage tear exposes the underlying bone.

A grade four lesion goes completely through all layers of the cartilage. Sometimes part of the torn cartilage will break off inside the joint. Since it is no longer attached to the bone, it can move around within the joint, causing more damage to the surface of the cartilage. Some doctors refer to this as a loose body.

Cartilage lacks a supply of blood or lymph vessels, which normally nourish other parts of the body. Without a direct supply of nourishment, cartilage is not able to heal itself if it gets injured. If the cartilage is torn all the way to the bone, the blood supply inside the bone is sometimes enough to start some healing inside the lesion. In cases like this, the body will form a scar, called a full-thickness lesion, in the area with a special type of cartilage called fibrocartilage. Fibrocartilage is a tough, dense, fibrous material that helps fill in the torn part of the cartilage. Yet it’s not an ideal replacement for the smooth articular cartilage that normally covers the surface of the knee joint.

Rationale

Articular cartilage lesions do not always cause symptoms. Just because there is no pain does not mean the lesion is not causing problems. In general, partially torn lesions do not heal by themselves, and they often get worse over time.

Full-thickness lesions may not cause any symptoms at first. The fibrocartilage that fills in the injured space often doesn’t match the shape of the joint surface. The body may have problems adapting to the altered shape of the joint, which can eventually even change the way the joint works.

When the lesion causes pain, surgery will most likely be recommended. If the lesion is not causing symptoms, surgeons will weigh many factors before recommending surgery, such as the patient’s age, lifestyle, and the overall condition of the knee.

Even if patients have pain, they may not have surgery right away. Doctors may start by recommending ways to manage the symptoms. This could be as simple as applying heat or ice and taking prescription medication. Often, doctors will recommend patients work with a physical therapist. A knee brace or shoe orthotic may be issued to improve knee alignment to ease pressure on the sore knee.

Surgical Treatments

Many types of surgery have been developed for fixing articular cartilage injuries in the knee. When the decision is made to go ahead with surgery, the doctor will consider whether to do a procedure to restore or to repair the cartilage. A reparative surgery helps fill in the lesion, but doesn’t restore the actual makeup and function of the articular cartilage.

Restorative surgery fills the lesion to the full depth with tissue almost identical to the original. One surgical method is to transplant cartilage and underlying bone from a nearby area in the knee joint. Another method is to take some primary cartilage cells (chondrocytes) from the knee, grow them in a laboratory, and then use the newly grown tissue to fill in the lesion at a later date.

Your doctor will decide which surgery to use based on your specific injury, age, activity level, and the overall condition of your knee.

Arthroscopic Debridement

Doctors use an arthroscope and small, specially designed instruments to see into the joint and trim the rough edges of cartilage and remove loose fragments. Arthroscopic debridement is referred to as chondroplasty. It is only intended to be a short-term solution, but it is often successful in relieving symptoms for a few years. This procedure is usually used when the lesion is too large for a grafting type procedure or the patient is older and an artificial knee is planned for the future.

Abrasion Arthroplasty

If the joint has become arthritic, the tissue within and below the lesion can become hard. During arthroscopy the surgeon can use a special instrument known as a burr to perform an abrasion arthroplasty. In this procedure, the surgeon carefully scrapes off the hard bone tissue from the surface of the lesion. The scraping action instigates a healing response in the bone. In time, new blood vessels enter the area and fill it with new fibrocartilage.

Microfracture

Doctors use a blunt instrument (awl) to poke a few tiny holes in the bone under the cartilage. This procedure is used to get the bone layer under the cartilage to produce a healing response. The fresh blood supply starts the healing response and triggers the body to start forming fibrocartilage inside the lesion.

Autologous Chondrocyte Implantation

Doctors may recommend this procedure for active, younger patients (twenty to fifty years old), when the bone under the lesion hasn’t been badly damaged, and when the size of the lesion is small (less than four centimeters in diameter). The doctor surgically removes a few chondrocytes from inside the knee cartilage. These cells are grown in a laboratory. At a later date, the patient returns for a second surgery, during which the doctor implants the newly grown cartilage into the lesion and covers it with a small flap of tissue. The cover holds the cells in place while they attach themselves to the surrounding cartilage and begin to heal.

Osteochondral Autograft

An autograft is a procedure for grafting tissue from the patient’s own body. The place where the graft is taken is called the donor site. In this case, doctors graft a small amount of bone (osteo) and cartilage (chondral) from the donor site to put into the lesion. Usually, the donor site for this procedure is on the joint surface of the injured knee. Doctors are careful to take the graft from a spot that won’t cause a lot of problems, usually on the top and outside border of the knee cartilage. The osteochondral autograft procedure has mostly been used to treat osteochondritis dissecans (OCD), a condition where a chunk of the cartilage and the layer of bone beneath have died.

Osteochondral Allograft

During this procedure, doctors graft tissue from another person. The osteochondral allograft procedure is mostly used after other surgeries have failed. It is not recommended for patients with osteoarthritis. One of the problems with this kind of procedure is the limited supply of donor tissue. This procedure usually involves placing rather large pieces of cartilage and bone in the joint. The allograft is usually held in place with metal screws or pins.

Complications

As with all major surgical procedures, complications can occur. This is not intended to be a complete list of complications, but these are some of the most common: anesthesia complications, infection, failure of implanted metal screws or pins, failure of surgery.

After Surgery

Since surgeons use different methods when treating articular cartilage lesions in the knee, the instructions patients need to follow after surgery depend on the doctor and the way the surgery was done.

Rehabilitation

Depending on the type of surgery, some doctors have their patients use a continuous passive motion (CPM) machine to help the knee begin to move and to alleviate joint stiffness. This machine is used on many different types of surgery involving joints and is usually started immediately after surgery. The machine simply straps to the leg and continuously bends and straightens the joint. This motion has been shown to reduce stiffness and pain, and help the joint surface heal better with less scarring.

Many doctors will have their patients take part in physical therapy after knee surgery for articular cartilage injuries. The first few physical therapy treatments are designed to help control the pain and swelling from the surgery. Physical therapists will also work with patients to make sure they are only putting a safe amount of weight on the affected leg.

With the exception of those who underwent the debridement method, patients will be instructed to avoid putting too much weight on their foot when standing or walking for up to six weeks. This gives the area time to heal. People treated with an allograft are often restricted in their weight bearing for up to four months.

Patients are strongly advised to follow the recommendations about how much weight is safe. They may require a walker or pair of crutches for up to six weeks to avoid putting too much pressure on the joint when they are up and about.

The physical therapist will choose exercises to help improve knee motion and to get the muscles toned and active again. At first, emphasis is placed on exercising the knee in positions and movements that don’t strain the healing part of the cartilage. As the program evolves, more challenging exercises are chosen to safely advance the knee’s strength and function.

Ideally, patients will be able to resume their previous lifestyle activities. Some patients may be encouraged to modify their activity choices, especially if an allograft procedure was used.

Anatomy

Ligaments are tough bands of tissue that connect the ends of bones. The posterior cruciate ligament (PCL) is located in the center of the knee joint. It connects the front of the femur (thighbone) and crosses to the back of the tibia (shinbone). The PCL is the primary stabilizer of the knee and the main controller of how far back the tibia moves under the femur. If the tibia moves too far back, the PCL can rupture.

The PCL is made of two thick bands of tissue bundled together. One part of the ligament tightens when the knee is bent; the other part tightens as the knee straightens. This is the reason the PCL is sometimes injured along with the ACL when the knee is forced to straighten too far, or hyperextend.

Causes

The most common way for the PCL to be injured is from a direct blow to the front of the knee while the knee is bent. The PCL controls how far backward the tibia moves in relation to the femur. If the tibia moves too far, the PCL can rupture.

Symptoms

The symptoms following a PCL tear can vary. Unlike an ACL tear, swelling is minimal with PCL injuries. The knee may also feel like it is giving way.

The pain and moderate swelling from the initial injury will usually go away after two to four weeks, but the knee may still feel unstable requiring treatment. If left untreated, long-term instability can lead to arthritis of the knee.

Diagnosis

The history of the knee and physical examination is probably the most important tool in diagnosing a ruptured or deficient PCL. During the physical examination, the surgeon will check to see if the tibia moves too far back on the femur. Tests are also done to see if other knee ligaments or joint cartilage have been injured.

The doctor may order X-rays to rule out a fracture. Ligaments and tendons do not show up on X-rays. Magnetic resonance imaging (MRI) is probably the most accurate test without actually looking into the knee. The MRI machine uses magnetic waves rather than X-rays to show the soft tissues of the body. This machine creates pictures that look like slices of the knee. The pictures show the anatomy, and any injuries, very clearly. This test does not require any needles or special dye and is painless.

In some cases, arthroscopy may be used to make the definitive diagnosis. Arthroscopy is a type of operation where a small fiber-optic TV camera is placed into the knee joint, allowing the orthopedic surgeon to look at the structures inside the joint directly. The vast majority of PCL tears are diagnosed without resorting to this type of surgery, though arthroscopy is sometimes used to repair a torn PCL.

Treatment

Non-Surgical Treatment

Initial treatment for a PCL injury focuses on decreasing pain and swelling in the knee. Rest and mild pain medications, such as acetaminophen, can help decrease these symptoms. A long-leg brace and crutches may be used initially to limit pain. Your doctor may allow you to put a normal amount of weight down while walking.

In less serious cases, PCL tears are usually treated with a progressive rehabilitation program. If you are returning to high-demand activities a knee brace may be needed. These braces are designed to replace knee stability when the PCL doesn’t function properly.

You most likely will receive physical therapy treatments after a PCL injury. Therapists treat swelling and pain with the use of ice, electrical stimulation, and rest periods with your leg supported in elevation.

Exercises are used to help you regain normal movement of joints and muscles.
Range of motion exercises should be started right away to help you regain full movement in your knee. This includes the use of a stationary bike, gentle stretching, and careful pressure applied to the knee by the therapist.

Exercises also improve the strength of the quadriceps muscles on the front of the thigh. As your symptoms ease and strength improves, you will be guided in specialized exercises to improve knee stability.

Surgery

If the PCL alone is injured, conservative treatment may be all that is necessary. When other structures in the knee are injured, surgery may be necessary.

The goal of surgery is to keep the tibia from moving too far back under the femur bone and to get the knee functioning normally again. Even when surgery is needed, most doctors will have you attend physical therapy for several visits before the surgery. Physical therapy before surgery helps reduce swelling, makes sure you can straighten your knee completely and can reduce the chances of scarring inside the joint. It can also help speed up recovery time after surgery.

Most surgeons now favor reconstruction of the PCL using a piece of tendon or ligament, called a graft, to replace the torn PCL. This surgery is often done using the arthroscope. Incisions are usually required around the knee, but the surgeon does not have to open the joint. The arthroscope is used to perform the work needed on the inside of the knee joint. Most PCL surgeries are done on an outpatient basis, and normally patients stay either one night in the hospital, or they go home the same day as the surgery.

In a typical surgical reconstruction, the torn ends of the PCL must first be removed. Once this has been done, the type of graft that will be used is determined. One of the most common tendons used for the graft material is the patellar tendon. This tendon connects the kneecap (patella) to the tibia.

Another very common graft involves using two of the hamstring muscle tendons that attach to the tibia just below the knee joint–the gracilis tendon and the semitendinosus tendon. By arranging the hamstring tendon into four strips, the graft has nearly the same strength as a patellar tendon graft.

If the patellar tendon is used, about one third of it is removed, with a plug of bone at either end. The bone plugs are rounded and smoothed. Holes are drilled in each bone plug to place sutures (strong stitches) that will pull the graft into place.

Holes are then drilled in the tibia and the femur to place the graft. These holes are placed so that the graft will run between the tibia and femur in the same direction as the original PCL. The graft is then pulled into position using sutures placed through the drill holes. Screws are used to hold the bone plugs in the drill holes.

In some cases, an allograft is used. An allograft is tissue that comes from someone else. This tissue is harvested from tissue and organ donors at the time of death and sent to a tissue bank. The tissue is checked for any type of infection, sterilized, and stored in a freezer. When needed, the tissue is ordered by the physician and used to replace the torn PCL. The advantage of using an allograft is that the surgeon does not have to disturb or remove any of the normal tissue from your knee to use as a graft. The operation usually takes less time because the graft does not need to be harvested from your knee.

Rehabilitation

Conservative treatment of an injured PCL will typically last six to eight weeks. You will be able to return to your activities when your quadriceps muscles are close to their normal strength, your knee stops swelling intermittently, and you no longer have problems with the knee giving way.

If you have surgery, you may use a continuous passive motion (CPM) machine immediately after your operation to help the knee begin to move and to alleviate joint stiffness. The machine straps to the leg and continuously bends and straightens the joint. This “continuous” motion is thought to reduce stiffness, ease pain, and keep extra scar tissue from forming inside the joint.

Your doctor may have you wear a protective knee brace for two to three weeks after surgery, in addition to using crutches to keep your knee safe. You will most likely be instructed to put a limited amount of weight down while you’re walking.

You may also take part in formal physical therapy after PCL reconstruction. The first few physical therapy treatments are designed to help control the pain and swelling from the surgery.

Therapists will begin to focus on range of motion exercises within three weeks. They take care to avoid letting the tibia sag back under the femur, as this can put strain on the healing graft.

Strengthening exercises for the quadriceps muscle are safe to begin right away. Muscle stimulation and biofeedback, which both involve placing electrodes over the quadriceps muscle, may be needed to stimulate the muscle and help retrain it.

When you regain full knee movement, reduced swelling, and improved strength, you’ll gradually be able to return to your daily activities. Some doctors prescribe the use of a functional brace for athletes who intend to return quickly to their sport.

You will probably be involved in a progressive rehabilitation program for four to nine months after surgery to ensure the best result from your PCL reconstruction. In the first six weeks following surgery, expect to see the physical therapist two to three times a week. If your surgery and rehabilitation go as planned, you may only need to do a home program and see your therapist every few weeks over the four to six month period.