Total Knee Replacement in Depth

In Ortho House, we aspire to provide orthopedic surgeons with world-class orthopedic products that assist them in their procedures and provide better healthcare services to patients in Egypt, the Middle East, and Africa. One of our major services in Ortho House is arthroplasty of knee replacement with all of its types.

Knee Replacement Surgery

Knee replacement surgery (arthroplasty) is a common operation that involves replacing a damaged, worn or diseased knee with an artificial joint. Knee replacement is one of the most successful orthopedic surgeries performed today. Ortho House has been providing surgeons with the required products to ensure patient safety and successful procedures.

Total knee arthroplasty or total knee replacement using Ortho House products is a common orthopedic surgery that consists of replacement of the articular surfaces (femoral condyles and tibial plateau) of the knee joint with smooth metal and highly cross-linked polyethylene plastic.

Arthroplasty surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness. Ortho House has always been keen to find the latest technologies in the world of arthroplasty. Total knee replacements are one of the most successful procedures in the orthopedic field specifically and the entire medical field in general – a major service provided by Ortho House.

The number of total knee arthroplasty surgeries has increased in developed countries – with younger patients now receiving total knee transplant.

After knee replacement surgeries using Ortho House products, most patients experience reduced or eliminated knee pain, increased ability to move and an overall improvement in quality of life – which is the main purpose of the procedure and Ortho House’s driving force.

Types of Knee Replacement Surgery

Generally, there are 2 main types of surgery that Ortho House products support:

• total knee replacement – both sides of the knee joint are replaced
• partial (half) knee replacement – only 1 side of the joint is replaced in a smaller operation with a shorter hospital stay and recovery period.

Anatomy of the Knee

To understand a total knee replacement, also known as total condylar knee arthroplasty, Ortho House will explain the structure of the knee, a complex joint that consists of three bones: the femur (thighbone), the tibia (shinbone), the patella (kneecap).

Strong ligaments attach the powerful muscles of the thigh and calf to the bones around the knee to control knee motion and function. Cartilage (such as the meniscus) and other soft tissues cover and cushion the bones to help them glide together smoothly.

Normally, when the knee is bent or straightened, the end of the femur rolls against the end of the tibia, and the patella glides in front of the femur.

When this cartilage that cushions the joint degrades or is worn away completely, the bones rub together and become scraped and rough. This friction causes inflammation known as osteoarthritis, which results in pain and stiffness that make walking and other movement difficult.

Ortho House knee replacement surgeries use implants to reduce the pain and stiffness. Ortho House’s implants used in knee replacement are smooth like the surfaces of a healthy knee.

When Is a Knee Replacement Needed?

Knee replacement surgery is usually necessary when the knee joint is so worn or damaged that the patient completely has reduced mobility and experiences severe pain even while resting.

The most common reason for knee replacement surgery is osteoarthritis. However, based on Ortho House’s understanding in knee arthroplasty, there are other health conditions that cause knee damage such as:

• Rheumatoid arthritis
• Hemophilia
• Gout
• Disorders that cause unusual bone growth
• Death of bone in the knee joint following blood supply problems
• Knee injury
• Knee deformity with pain and loss of cartilage

Total knee replacement surgery aims to improve the quality of life of individuals with end-stage osteoarthritis by reducing pain and increasing knee function.

How Is Total Knee Replacement Performed?

To determine whether a knee replacement is recommended for a specific condition, an orthopedic surgeon assesses the knee’s range of motion, stability and strength. A knee replacement might be more accurately termed a knee “resurfacing” because only the surface of the bones is replaced rather than the entire knee structure.

Here, Ortho House will explain the four basic steps to a knee replacement procedure:

1. The preparation of the bone:

The damaged cartilage surfaces at the ends of the femur and tibia are surgically removed along with a small amount of underlying bone.

1. Positioning the Ortho House metal implants:

The removed cartilage and bone are replaced with Ortho House metal components that recreate the surface of the joint. These Ortho House metal parts may be cemented or “press-fit” into the bone.

1. Resurfacing of the patella:

The undersurface of the patella (kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending upon the case.

1. Insertion of a spacer:

A medical-grade plastic spacer is inserted between the metal components to create a smooth gliding surface.

What Are Ortho House Knee Replacement Implants Made of?

The selection of knee replacement prosthesis design and materials depends on each individual patient and their specific case. The main Ortho House implant components are made of metal – usually titanium or chrome-cobalt alloys.

The Ortho House implants are fixed in place either with a cement bonding agent or by “osseointegration” – in which a porous metal stem extends into the tibia and the patient’s natural bone grows into it. During the procedure, a plastic platform or spacer will be inserted between the tibial and femoral implant surfaces. The spacer is made of polyethylene.

Most of Ortho House’s femoral components consist of metal alloys (cobalt chromium) or metal-ceramic alloys (oxidized zirconium). The patellar component is plastic (polyethylene). The Ortho House tibial insert component is also made of plastic (polyethylene). The tibial tray component can be made of the following materials:

• cobalt chromium (metal alloy)
• titanium (metal alloy)
• polyethylene (plastic)

How Long Does a Knee Replacement Last?

Implants do not last forever. However, knee replacement implants are likely to remain functional for at least 15 to 20 years in 85% to 90% of patients.

After a period of 15 to 20 years, general wear and tear may loosen the implant – which is completely normal. Depending on the patient, this may cause no symptoms, or it may cause any of the following:

• Pain
• Loose implant particles
• Knee instability
• Infection

When these symptoms arise, Ortho House recommends having knee revision surgery to replace the original implant. Infection after knee replacement surgery is rare, but a knee replacement implant cannot defend itself from infection if bacteria are introduced to the body, hence, it requires a prompt revision surgery.