The knee is a complex joint of the body which is vital for movement. The four major ligaments of the knee are anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament and lateral collateral ligament. They play an important role in maintaining the stability of the knee. An injury resulting in tear of one or more ligaments of the knee thus affects knee stability.  Such injuries occur as a result of direct blow to the knee, or a fall from a height, or motor vehicle trauma. Multiple ligament knee injuries are common in athletes involved in contact sports such as soccer, football and basketball. Patients with multi-ligament knee injuries may experience pain, swelling, limited range of motion, injuries to nerves and arteries of the leg, and knee instability.

Sometimes, knee pain due to other injuries results in involuntary movements that give the sensation of instability. A thorough examination by an experienced doctor is very crucial for the correct diagnosis of multiligament instability.

Usually grade I (mild tear) and grade II (partial tear) multiligament injuries are treated conservatively with rest, ice, compression and elevation. But, treatment of grade III (complete tear) multiligament injuries requires surgery. Moreover, unlike grade III single ligament injury, the surgery is usually performed soon after the injury and often involves more than one surgery.

The surgical reconstruction is usually performed arthroscopically. The surgery involves reconstruction of the torn ligament using a tissue graft taken from another part of the body, or from a donor. The damaged ligament is replaced by the graft and fixed to the femur and tibia using metallic screws. Gradually, over a period of few months, the graft heals.

After the multi-ligament knee reconstruction surgery, crutches may be required for 6 to 8 weeks. Most patients can also return to their high level sport after a period of rehabilitation.

Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for a number of reasons; often the definite cause is not known.

When the articular cartilage wears out the bone ends rub on one another and cause pain. This condition is referred to as Osteoarthritis or “wear and tear” arthritis as it occurs with aging and use. It is the most common type of arthritis.

Causes of Arthritis

There are numerous conditions that can cause arthritis but often the exact cause is never known. In general, but not always, it affects people as they get older (Osteoarthritis).Other causes include:

• Trauma (fracture)
• Increased stress such as overuse and overweight
• Infection of the bone
• Connective tissue disorders
• Inactive lifestyle and Obesity (overweight); Your weight is the single most important link between diet and arthritis as being overweight puts an additional burden on your hips, knees, ankles and feet.
• Inflammation (Rheumatoid arthritis)

Symptoms

Knee Arthritis causes pain and decreased mobility of the knee joint. In the arthritic knee there is an absent joint space that shows on X-ray.  In the normal knee there is a normal joint space.

Arthritic knee

The cartilage lining is thinner than normal or completely absent. The degree of cartilage damage and inflammation varies with the type and stage of arthritis. The capsule of the arthritic knee is swollen. The joint space is narrowed and irregular in outline; this can be seen in an X-ray image.  Bone spurs or excessive bone can also build up around the edges of the joint. The combinations of these factors make the arthritic knee stiff and limit activities due to pain or fatigue.

The knee can be divided into three compartments: patellofemoral, medial and lateral compartment. The patellofemoral compartment is the compartment in the front of the knee between the knee cap and thigh bone. The medial compartment is the area on the inside portion of the knee, and the lateral compartment is the area on the outside portion of the knee joint. Patellofemoral instability means that the patella (kneecap) moves out of its normal pattern of alignment. This malalignment can damage the underlying soft structures such as muscles and ligaments that hold the knee in place.

Causes

Patellofemoral instability can be caused because of variations in the shape of the patella or its trochlear groove as the knee bends and straightens. Normally, the patella moves up and down within the trochlear groove when the knee is bent or straightened. Patellofemoral instability occurs when the patella moves either partially (subluxation) or completely (dislocation) out of the trochlear groove.

A combination of factors can cause this abnormal tracking and include the following:

Anatomical defect- Flat feet or fallen arches and congenital abnormalities in the shape of the patella bone can cause misalignment of the knee joint.

Abnormal Q Angle- The high Q angle (angle between the hips and knees) often results in mal tracking of the patella such as in patients with knock knees.

Patellofemoral Arthritis- Patellofemoral arthritis occurs when there is a loss of the articular cartilage on the back of the kneecap. This can eventually lead to abnormal tracking of the patella.

Improper Muscle Balance- Weak quadriceps (anterior thigh muscles) can lead to abnormal tracking of the patella, causing it subluxate or dislocate.

Young active individuals involved in sports activities are more prone to patellofemoral instability.

Symptoms

Patellofemoral instability causes pain when standing up from a sitting position and a feeling that the knee may buckle or give way. When the kneecap slips partially or completely you may have severe pain, swelling, bruising, visible deformity and loss of function of the knee. You may also have sensational changes such as numbness or even partial paralysis below the dislocation as a result of pressure on nerves and blood vessels.

Diagnosis

Your doctor evaluates the source of patellofemoral instability based on your medical history and physical examination. Other diagnostic tests such as X-rays, MRI and CT scan may be done to determine the cause of your knee pain and to rule out other conditions.

Conservative Treatment

If your kneecap is only partially dislocated (subluxation), your physician may recommend non-surgical treatments, such as pain medications, rest, ice, physical therapy, knee-bracing, and orthotics. If the kneecap has been completely dislocated, the kneecap may need to be repositioned back in its proper place in the groove. This process is called closed reduction.

If your kneecap is only partially dislocated (subluxation), your physician may recommend non-surgical treatments, such as pain medications, rest, ice, physical therapy, knee-bracing, and orthotics. If the kneecap has been completely dislocated, the kneecap may need to be repositioned back in its proper place in the groove. This process is called closed reduction.

Surgical Treatment

Surgery is sometimes needed to help return the patella to a normal tracking path when other non-surgical treatments have failed. The aim of the surgery is to realign the kneecap in the groove and to decrease the Q angle.

Patellar realignment surgery is broadly classified into proximal re-alignment procedures and distal re-alignment procedures.

Proximal re-alignment Procedures: During this procedure, structures that limit the movements on the outside of the patella are lengthened or ligaments on the inside of the patella are shortened.

Distal re-alignment Procedures: During this procedure, the Q angle is decreased by moving the tibial tubercle towards the inner side of the knee.

The surgery is performed under sterile conditions in the operating room under spinal or general anesthesia. The surgeon will make two or three small cuts around your knee. The arthroscope, a narrow tube with a tiny camera on the end is inserted through one of the incisions to view the knee joint. Specialized instruments are inserted into the joint through other small incisions. The camera attached to the arthroscope displays the image of the joint on the monitor. A sterile solution will be pumped into your knee in order to stretch the knee and provide a clear view and room for the surgeon to work. With the images from the arthroscope as a guide the surgeon can look for any pathology or anomaly and repair it through the other incisions with various instruments. After the evaluation is completed, a larger incision is made over the front of the knee. Depending on your situation, a lateral retinacular release may be performed. In this procedure, the tight ligaments on the outer side of the knee are released, thus allowing the patella to sit properly in the femoral groove. Your surgeon may also tighten the tendons on the inside, or medial side of the knee to realign the quadriceps.

In cases where the malalignment is severe, a procedure called a tibial tubercle transfer (TTT) will be performed. In this procedure a section of bone where the patellar tendon attaches to the tibia is removed. This bony section is then shifted and properly realigned with the patella and reattached to the tibia using screws. Once the malalignment is repaired and confirmed with arthroscopic evaluation, the incisions are closed with sutures.

Postoperative Care

Your doctor will recommend pain medications to relieve pain. To help reduce the swelling you will be instructed to elevate the leg and apply ice packs over the knee. Crutches are necessary for the first few weeks to prevent weight bearing on the knee. A knee immobilizer may be used to stabilize the knee. You will be instructed about the activities to be avoided and exercises to be performed for a faster recovery. A rehabilitation program may be advised for a speedy recovery.

Risks & Complications

• Possible risks and complications associated with the surgery include:
• Loss of ability to extend the knee
• Recurrent dislocations or subluxations
• Arthrofibrosis (thick fibrous material around the joint)
• Persistent pain

Patients with patellofemoral instability have problems with the alignment of the knee cap. Therefore, treatment is necessary to bring the knee cap back into normal alignment. Your surgeon will decide which procedure is appropriate for your particular situation.

Knee Arthroscopy is a common surgical procedure performed using an arthroscope, a viewing instrument, to look into the knee joint to diagnose or treat a knee problem. It is a relatively safe procedure and a majority of the patient’s discharge from the hospital on the same day of surgery.

Knee Anatomy

The knee joint is one of the most complex joints of the body. The lower end of the thighbone (femur) meets the upper end of the shinbone (tibia) at the knee joint. A small bone called the patella (kneecap) rests on a groove on the front side of the femoral end. A bone of the lower leg (fibula) forms a joint with the shinbone.

To allow smooth and painless motion of the knee joint, articular surfaces of these bones are covered with a shiny white slippery articular cartilage. Two C-shaped cartilaginous menisci are present in between the femoral end and the tibial end.

Menisci act as shock absorbers providing cushion to the joints. Menisci also play an important role in providing stability and load bearing to the knee joint.

Bands of tissue, including the cruciate and collateral ligaments, keep the different bones of the knee joint together and provide stabilization to the joint. Surrounding muscles are connected to the knee bones by tendons. The bones work together with the muscles and tendons to provide mobility to the knee joint. The whole knee joint is covered by a ligamentous capsule, which further stabilizes the joint. This ligamentous capsule is also lined with a synovial membrane that secretes synovial fluid for lubrication.

Indications for Knee Arthroscopy

The knee joint is vulnerable to a variety of injuries. The most common knee problems where knee arthroscopy may be recommended for diagnosis and treatment are:

• Torn meniscus
• Torn or damaged cruciate ligament
• Torn pieces of articular cartilage
• Inflamed synovial tissue
• Misalignment of patella
• Baker’s cyst: a fluid filled cyst that develops at the back of the knee due to the accumulation of synovial fluid. It commonly occurs with knee conditions such as meniscal tear, knee arthritis and rheumatoid arthritis.
• Certain fractures of the knee bones

Procedure

Knee arthroscopy is performed under local, spinal, or general anesthesia. Your anesthesiologist will decide the best method for you depending on your age and health condition.

• The surgeon makes, two or three small incisions around the knee.
• Next, a sterile saline solution is injected into the knee to push apart the various internal structures. This provides a clear view and more room for the surgeon to work.
• An arthroscope, a narrow tube with a tiny video camera on the end, is inserted through one of the incisions to view the knee joint. The structures inside the knee are visible to the surgeon on a video monitor in the operating room.
• The surgeon first examines the structures inside the knee joint to assess the cause of the problem.
• Once a diagnosis is made, surgical instruments such as scissors, motorized shavers, or lasers are inserted through another small incision, and the repair is performed based on the diagnosis.

The repair procedure may include any of the following:

• Removal or repair of a torn meniscus
• Reconstruction or repair of a torn cruciate ligament
• Removal of small torn pieces of articular cartilage
• Removal of loose fragments of bones
• Removal of inflamed synovial tissue
• Removal of baker’s cyst
• Realignment of the patella
• Making small holes or microfractures near the damaged cartilage to stimulate cartilage growth
• After the repair, the knee joint is carefully examined for bleeding or any other damage.
• The saline is then drained from the knee joint.
• Finally, the incisions are closed with sutures or steri-strips, and the knee is covered with a sterile dressing.

After the Surgery

Most patients are discharged the same day after knee arthroscopy. Recovery after the surgery depends on the type of repair procedure performed. Recovery from simple procedures is often fast. However, recovery from complicated procedures takes a little longer. Recovery from knee arthroscopy is much faster than that from an open knee surgery.

Pain medicines are prescribed to manage pain. Crutches or a knee brace may be recommended for several weeks. A rehabilitation program may also be advised for a successful recovery. Therapeutic exercises aim to restore motion and strengthen the muscles of the leg and knee.

Risks & Complications

Knee arthroscopy is a safe procedure and complications are very rare. Complications specific to knee arthroscopy include bleeding into the knee joint, infection, knee stiffness, blood clots or continuing knee problems.