The knee is a complex joint made up of different structures including bones, tendons, ligaments and muscles. They all work together to maintain normal function and provide stability to the knee during movement.

The Knee is a hinge joint made up of two bones, the thigh bone (femur) and the shinbone (tibia). There are two round knobs at the end of the femur called femoral condyles which articulate with the flat surface of the tibia called the tibial plateau. The tibia plateau on the inside of the leg is called the medial tibial plateau, and on the outside of the leg it is called the lateral tibial plateau.

The two femoral condyles form a groove on the front (anterior) side of the knee called the patellofemoral groove. A small bone called the patella sits in this groove and forms the knee cap. It acts as a shield and protects the knee joint from direct trauma.

A fourth bone called the fibula is the other bone of the lower leg. This forms a small joint with the tibia. This joint has very little movement and is not considered a part of the main joint of the knee.

Movement of the bones causes friction between the articulating surfaces. To reduce this friction, all articulating surfaces involved in movement are covered with a white, shiny, slippery layer called articular cartilage. The articulating surface of the femoral condyles, tibial plateaus and the back of the patella are covered with this cartilage. The cartilage provides a smooth surface that facilitates easy movement.

To further reduce friction between the articulating surfaces of the bones, the knee joint is lined by a synovial membrane which produces a thick clear fluid called synovial fluid. This fluid lubricates and nourishes the cartilage and bones inside the joint capsule.

Within the knee joint between the femur and tibia there are two C shaped cartilaginous structures called menisci. Menisci function to provide stability to the knee by spreading the weight of the upper body across the whole surface of the tibial plateau. The menisci help in load bearing by preventing the weight from concentrating onto a small area, which could damage the articular cartilage. The menisci also act as a cushion between the femur and tibia by absorbing the shock produced by activities such as walking, running and jumping.

Ligaments are tough bands of tissue that connect one bone to another bone. The ligaments of the nee function to stabilize the knee joint. There are two important groups of ligaments that hold the bones of the knee joint together, collateral ligaments and the cruciate ligaments.

Collateral ligaments are present on either side of the knee. They function to prevent the knee from moving too far during side to side motion. The collateral ligament on the inside is called the medial collateral ligament (MCL) and the collateral ligament on the outside is called the lateral collateral ligament (LCL).

Cruciate ligaments- This group of ligaments, present inside the knee joint, control the back and forth motion of the knee. The Cruciate ligament in the front of the knee is called anterior cruciate ligament or ACL and the cruciate ligament in the back of the knee is called posterior cruciate ligament or PCL.

The knee is a complex joint with many different parts that function together to allow movement and provide support to the body’s full weight when standing, walking and running.

Total knee replacement, also called total knee arthroplasty, is a surgical procedure in which the worn out or damaged surfaces of the knee joint are removed and replaced with artificial parts.

Total knee replacement surgery is commonly indicated for severe osteoarthritis of the knee. Osteoarthritis is the most common form of knee arthritis in which the joint cartilage gradually wears away. It often affects older people.

In a normal joint, articular cartilage allows for smooth movement within the joint, whereas in an arthritic knee the cartilage itself becomes thinner or completely absent. In addition, the bones become thicker around the edges of the joint and may form bony “spurs”. All of these factors can cause pain and restricted range of motion in the joint.

Your doctor may advise total knee replacement if you have:

Severe knee pain which limits your daily activities (such as walking, getting up from a chair or climbing stairs).

Moderate to severe pain that occurs during rest or awakens you at night.

Chronic knee inflammation and swelling that is not relieved with rest or medications

Failure to obtain pain relief from medications, injections, physical therapy, or other conservative treatments.

The exact cause of osteoarthritis is not known, however there are a number of factors that are commonly associated with the onset of arthritis and may include:

- Injury or trauma to the joint

- Fractures at the knee joint

- Increased body weight

- Repetitive overuse

- Joint infection

- Inflammation of the joint

- Connective tissue disorders

Your doctor will diagnose osteoarthritis based on the medical history, physical examination, and X-rays. X-rays typically show a narrowing of the joint space in the arthritic knee.

The goal of total knee replacement surgery is to relieve pain and restore the alignment and function of your knee.

Knee arthroscopy, or arthroscopic knee surgery, is a surgery that uses arthroscopic techniques.

It has, in many cases, replaced the classic open surgery (arthrotomy) that was performed in the past. Arthroscopic knee surgery is one of the most common orthopaedic procedures, performed approximately 2 million times worldwide each year. The procedures are more commonly performed to treat meniscus injury and to perform anterior cruciate ligament reconstruction.

During an average knee arthroscopy, a small fiberoptic camera (the arthroscope) is inserted into the joint through a small incision, about 4 mm (1/8 inch) long. More incisions might be performed in order to visually check other parts of the knee and to insert the miniature instruments that are used to perform surgical procedures.

Knee arthroscopy can be done under general, regional, or local anesthesia. After adequate anesthesia, your surgeon will create 'portals' to gain access to the knee joint. The portals are placed in specific locations to minimize the potential for injury to surrounding nerves, blood vessels, and tendons. Through one portal, a camera is placed into the joint, and through others, small instruments can be used to address the problem. Patients who have arthroscopic knee surgery under a regional or local anesthesia can often watch their surgery on a monitor to see what is causing their problem.

Arthritis is inflammation of one or more of your joints. Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in the knee.

Although there is no cure for arthritis, there are many treatment options available to help manage pain and keep people staying active.

The word arthritis refers to inflammation of the joints. Types of arthritis include those related to wear and tear of cartilage, such as osteoarthritis, to those associated with inflammation resulting from an overactive immune system (such as rheumatoid arthritis).

Knee arthritis can make it hard to do many everyday activities, such as walking or climbing stairs. It is a major cause of lost work time and a serious disability for many people.

The most common types of arthritis are osteoarthritis and rheumatoid arthritis, but there are more than 100 different forms. While arthritis is mainly an adult disease, some forms affect children.

A knee joint affected by arthritis may be painful and inflamed. Generally, the pain develops gradually over time, although sudden onset is also possible. There are other symptoms, as well:

The joint may become stiff and swollen, making it difficult to bend and straighten the knee.

Pain and swelling may be worse in the morning, or after sitting or resting.

Vigorous activity may cause pain to flare up.

Loose fragments of cartilage and other tissue can interfere with the smooth motion of joints. The knee may "lock" or "stick" during movement. It may creak, click, snap or make a grinding noise (crepitus).

Pain may cause a feeling of weakness or buckling in the knee.

Many people with arthritis note increased joint pain with rainy weather.

Your doctor may recommend surgery if your pain from arthritis causes disability and is not relieved with nonsurgical treatment. As with all surgeries, there are some risks and possible complications with different knee procedures. Your doctor will discuss the possible complications with you before your operation.