Knee and hip replacements are becoming standard orthopedic procedures for many reasons, including age, injury, and conditions like osteoarthritis. Knee and hip replacement surgeries are among the most successful surgeries today.

The Orthopedics and Sports Medicine Department at Burjeel Medical City (BMC), Abu Dhabi, leads in delivering world-class treatments and procedures with its advanced diagnostic, surgical and rehabilitation technologies.

Our orthopedic and trauma surgeons and a multidisciplinary team comprising occupational therapists, nurses, physiotherapists, and orthotics practitioners are renowned for creating exceptional orthopedic care outcomes.

Let us understand knee and hip replacements.

Knee Anatomy

Essentially, the knee comprises four bones, of which two are long leg bones kept together by muscles, ligaments, and tendons. The femur or thighbone connects the hip and knee, and the tibia connects the knee to the ankle. The patella or the kneecap covers the knee joint. Fibula, a shorter, thinner bone, runs parallel to the tibia.

The end of each bone is cased in a sheath of cartilage to absorb shock and prevent bones from coming into contact.

Ligaments are bands of tissue that connect bone to bone and keep them in place. The knee has four ligaments:

  • The anterior cruciate ligament (ACL) in the center of the knee is the most common cause of injury and wear and tear.
  • A posterior cruciate ligament (PCL) at the back of the knee.
  • Collateral ligaments Medial collateral and Lateral Collateral ligament (LCL) help keep the knee in place.

These ligaments are critical for knee movement, stability, and balance.

What is a Knee Replacement?

When a significant part of the knee is damaged or worn out and unable to function. The individual experiences severe pain and loss of mobility, which requires the critical parts of the knee to be replaced with an artificial joint to restore mobility. This procedure is called knee replacement.

Osteoarthritis of the Knee:

When the ends of the knee bones, the femur, and tibia, which form a joint, get damaged due to cartilage wearing out, the knee experiences intense pain because the bones begin to rub against one another — this loss of cushioning leads to joint inflammation or osteoarthritis.

It leads to severe mobility issues, and the person cannot do activities such as walking, climbing stairs, bending, sitting, or straightening up.

Osteoarthritis is caused by age, joint wear and tear, or changes in the knee tissue. Injuries can also damage cartilage.

Symptoms of osteoarthritis of the knee:

  • Pain when walking or sitting. Joint stiffness after a period of rest.
  • Limited joint movement.
  • Knee deformity: knee bows outwards or towards the bowing in or out of the knee.

How do I know I Need a Replacement?

You have chronic knee pain, which is not improving with medicines and physiotherapy. You cannot move freely, climb, or get into or out of cars and do everyday movements, and your knees look swollen or are changing shape; you need to consult an orthopedic specialist.

The orthopedic surgeon will devise the right approach depending on your age, knee anatomy, and health.

Knee Replacement Surgery

The first thing to understand about knee replacement is your knee will not be entirely removed to be replaced by an artificial knee; only the worn-out bone surfaces and cartilage are replaced. 

There are two kinds of knee replacement surgeries: 

  • Total Knee Replacement (TKR): The worn-out cartilage and bone surface are removed, and metal surfaces are placed with special bone cement. If required, the kneecap or patella is cut to fit the new surface contour, and a metal buffer is inserted between the metal parts to keep out friction. All measurements are exact to the nth degree to ensure a perfect fit for the knee.
  • Partial Knee Replacement: For damage in one hip.

Hip Replacement Surgery

Anatomy of the Hip

The hip connects the legs to the body’s trunk. The hip has two bones: the pelvis (ilium, ischium, and pubis) and the femur or thigh bone. The head of the femur forms the hip joint in the socket or acetabulum. So, the hip is a ball-and-socket joint.

It has ligaments connecting bone to bone, tendons connecting bone to muscles, and bands of muscle and cartilage.

What is Hip Replacement?

When the hip bones and cartilage wear out due to hip arthritis or suffer severe injury or accident that severely impairs mobility, or the hip has a fracture that won’t heal, hip replacement surgery is usually recommended. The procedure involves replacing worn-out portions of the hip joint bones and cartilage to restore mobility and movement.

Arthritis of Hip

Wear and tear of the hip due to aging cause osteoarthritis. The cartilage wears out, and the cushioning reduces for the ball and socket joint, with bone rubbing on bone leading to intense pain, stiffness, and discomfort. There are different forms of hip arthritis, and loss of cartilage is common to all.

The most common reason for hip replacement surgery is osteoarthritis. Other conditions include rheumatoid arthritis, hip fracture, septic arthritis (infection in the joint fluid and joint tissues and unusual bone growth in the hip.

Symptoms of Arthritis:

  • Pain in hip joints and the leg.


  •  Clicking sounds during hip movement.
  • Difficulty in sitting, bending, climbing, and straightening up.
  • Hip lock.
  • Difficulty in sleeping due to hip pain.

How do I know I need a Hip Replacement?

When you have the above symptoms, you are chronically unable to perform everyday activities, and your quality of life has deteriorated due to your hip problem, you need to consult an orthopedic specialist to see if hip replacement is required.

Depending on your age, hip condition, and health, the orthopedic surgeon will devise the right approach.

Hip Replacement Surgery

The first thing to understand about hip replacement is your entire hip will not be removed to be replaced by an artificial one; only the worn-out bone surfaces and cartilage are replaced. 

Hip replacement surgeries are of the following types:

  • Total Hip Replacement: The worn-out ball and socket of the hip are removed and replaced with artificial implants.
  • Partial Hip Replacement: It involves only one side of the hip joint.
  • Hip Resurfacing: It is an alternative to total hip replacement, where the worn-out cartilage and socket are replaced.