Knee Replacement Surgery

Knee Replacement Surgery:

Knee arthritis is very prevalent in our country as compared to the western population. It's because of our social and cultural habits. Knee replacement surgery is done for the painful, arthritic knee joint. It's all about pain management and quality of life.

The knee is the largest and complex joint in the body. The knee joint is important for walking and most of our day to day activities. The knee joint is formed between the lower end of the femur (thigh bone), the upper end of tibia (leg bone) and patella. The ends of all these bones are covered by a cushion called cartilage so that movement occurs between the soft cartilages over the other soft cartilage.

There are smooth discs in between the bones known as menisci. These act as “shock absorbers” of the joint.

Two strong and two outside strong ligaments hold the bones together and provide stability. Quadriceps and hamstring muscle group give the knee strength. Inside the joint, there is a membrane called as a synovial membrane.

Arthritis:

Arthritis is of many types:

1. Osteoarthritis - This is usually the most common type in India. It's degenerative arthritis because of wear and tear of the cartilage. Arthritis sets in when the cartilage over the bone ends get eroded and the abrasion bone starts rubbing against the bone giving rise to pain.

2. Secondary/Post-Traumatic Arthritis - This is because of previous injuries leading to fractures and ligament tears. It's mechanical type and causes the weight bearing forces passes in an abnormal fashion. Because of the abnormal stresses and forces there occurs the accelerated wear and tear leading to the arthritis.

3. Rheumatoid And Seronegative Spondyloarthropathies - This is the primary inflammatory type. The primary pathology lies within the synovial membrane. The pathologic membrane damages the cartilage leading to pain and arthritis.

Clinical Features

1. Pain

The main feature of arthritis is pain. Pain occurs every time when there are movement and weight bearing. The abrasion bone ends rub over each other every time there is movement.

• Difficulty and pain in getting up from the chair
• Pain on squatting down, kneeling
• Pain while climbing up and down the stairs
• Pain and difficulty on long-standing

2. Deformity

Bowing of the leg and knee joint. Varus is more common deformity in India as compared to Valgus.

Total Knee Replacement

Knee replacement is the surgery where this degenerated and eroded bone ends are cut with minimum thickness and are replaced by metal and poly. Thus a new joint is formed between the poly and metal.

There are different types of the Endoprosthesis used for the surgery. Following are the types according to the design—

1. All Poly - Used where bone stock is good. Cheaper but less used.

2. Metal Back - Most commonly used type.

3. High-Flexion Knee - Allows more bending post-surgery.

4. Improved Material - Latest materials increase durability and natural feel.