Partial Knee Replacement

The goal of knee replacement surgery is to decrease pain and restore function. Although total knee replacement (also called “arthroplasty”) is an excellent option for patients with osteoarthritis of the knee, other surgical options exist.

Patients with osteoarthritis that is limited to just one part of the knee may be candidates for unicompartmental knee replacement (also called a “partial” knee replacement).

Unicompartmental knee replacement is an option for a small percentage of patients with osteoarthritis of the knee.

Your Wisconsin Bone & Joint orthopaedic doctor may recommend partial knee replacement if your arthritis is confined to a single part (compartment) of your knee.

Your knee is divided into three major compartments: The medial compartment (the inside part of the knee), the lateral compartment (the outside part), and the patellofemoral compartment (the front of the knee between the kneecap and thighbone).

In a unicompartmental knee replacement, only the damaged compartment is replaced with metal and plastic. The healthy cartilage and bone in the rest of the knee is left alone.

Advantages of Partial Knee Replacement

Multiple studies have shown that modern unicompartmental knee replacement performs very well in the vast majority of patients who are appropriate candidates. The advantages of partial knee replacement over total knee replacement include:

  • Quicker recovery
  • Less pain after surgery
  • Less blood loss
  • Also, because the bone, cartilage, and ligaments in the healthy parts of the knee are kept, most patients report that a unicompartmental knee replacement feels more “natural” than a total knee replacement.
  • A unicompartmental knee may also bend better.

Partial Knee Replacement

A partial knee replacement operation typically lasts between 1 and 2 hours.

Your WBJ surgeon will make an incision at the front of your knee exploring the three compartments of your knee to verify that the cartilage damage is, in fact, limited to one compartment and that your ligaments are intact.

If your surgeon feels that your knee is unsuitable for a partial knee replacement, he or she will instead perform a total knee replacement.

He or she will discuss this contingency plan with you before your operation to make sure that you agree with this strategy.

If your knee is suitable for a partial knee replacement, your surgeon will use special saws to remove the cartilage from the damaged compartment of your knee and will cap the ends of the femur and tibia with metal coverings. The metal components are generally held to the bone with cement. A plastic insert is placed between the two metal components to allow for a smooth gliding surface.

Total Knee Replacement

When the cartilage has worn away, an artificial knee (called a prosthesis) can take its place. The surgery to implant the prosthesis is termed a total knee replacement.

If your knee is severely damaged by arthritis or injury, it may be hard for you to perform simple activities, such as walking or climbing stairs. You may even begin to feel pain while you are sitting or lying down.

If you are suffering severe knee pain you may have made the decision to have a knee replacement operation. Your doctor has probably explained to you many of the benefits and some of the details of your procedure.

You are undoubtedly looking forward to restored mobility, loss of the pain you are currently experiencing, and resuming many of your regular activities. It is important that you are also be mindful of the fact that no recovery occurs without patience and due diligence throughout the healing process.

When nonsurgical treatments like medications and using walking supports are no longer helpful, you may want to consider total knee replacement surgery.

Cause

The most common cause of chronic knee pain and disability is arthritis.

Although there are many types of arthritis, most knee pain is caused by just three types: osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.

Osteoarthritis

This is an age-related “wear and tear” type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people, too. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.

Rheumatoid arthritis

This is a disease in which the synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed “inflammatory arthritis.”

Post-traumatic arthritis. This can follow a serious knee injury. Fractures of the bones surrounding the knee or tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function. Osteoarthritis often results in bone rubbing on bone. Bone spurs are a common feature of this form of arthritis.

Joint replacement surgery is a safe and effective procedure to relieve pain, correct leg deformity, and help you resume normal activities. Knee replacement surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness.

Procedure

When the cartilage has worn away, an artificial knee (called a prosthesis) can take its place. The surgery to implant the prosthesis is termed a total knee replacement.

Only the surface of the joint is removed – the arthritic ends of the bones are shaved off and replaced with new metal and plastic surfaces.

The knee replacement recreates the normal function of the knee. While the idea of getting an artificial knee joint may be frightening to some, it is one of the most effective surgical procedures leading to significant improvement in quality of life.

Maintaining your post surgical treatment care is almost as important as getting the surgery itself. Our surgical procedures and rehabilitative practices may be highly advanced, but your attention to detail is also an important component of your total knee replacement recovery.

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