Knee

Meniscus Tear

Meniscus tear is the commonest knee injury in athletes, especially those involved in contact sports. A suddenly bend or twist in your knee cause the meniscus to tear. This is a traumatic meniscus tear. Elderly people are more prone to degenerative meniscal tears as the cartilage wears out and weakens with age. The two wedge-shape cartilage pieces’ present between the thighbone and the shinbone are called meniscus. They stabilize the knee joint and act as “shock absorbers”.

Torn meniscus causes pain, swelling, stiffness, catching or locking sensation in your knee making you unable to move your knee through its complete range of motion. Your orthopaedic surgeon will examine your knee, evaluate your symptoms, and medical history before suggesting a treatment plan. The treatment depends on the type, size and location of tear as well your age and activity level. If the tear is small with damage in only the outer edge of the meniscus, nonsurgical treatment may be sufficient. However, if the symptoms do not resolve with nonsurgical treatment, surgical treatment may be recommended.

Surgical Treatment

Knee arthroscopy is the commonly recommended surgical procedure for meniscal tears. The surgical treatment options include meniscus removal (meniscectomy), meniscus repair, and meniscus replacement. Surgery can be performed using arthroscopy where a tiny camera will be inserted through a tiny incision which enables the surgeon to view inside of your knee on a large screen and through other tiny incisions, surgery will be performed. During meniscectomy, small instruments called shavers or scissors may be used to remove the torn meniscus. In arthroscopic meniscus repair the torn meniscus will be pinned or sutured depending on the extent of tear.

Meniscus replacement or transplantation involves replacement of a torn cartilage with the cartilage obtained from a donor or a cultured patch obtained from laboratory. It is considered as a treatment option to relieve knee pain in patients who have undergone meniscectomy.

Patellofemoral Instability

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 because 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.

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 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 and 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 situation.

Arthritis of Knee Joint

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 several 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.