Unicondylar Knee Replacement

Unicompartmental knee replacement is a joint preserving surgery in which only the damaged compartment of the knee is replaced with an implant. It is also called a partial knee replacement. The knee can be divided into three compartments:

Patellofemoral compartment: the compartment in front of the knee between the knee cap and thigh bone

Medial compartment: the compartment which is on the inner side of the knee, and

Lateral compartment: the compartment which is the outer portion of the knee joint.

Advantages of Unicondylar Knee Replacement

Since only a part of the joint is replaced in a unicondylar procedure, the surgery often can be performed through a smaller incision and involves less bone and soft tissue dissection, thereby offering potential benefits in the early rehabilitation period. Most studies have shown that a unicondylar knee replacement results in less blood loss and a lower incidence of medical complication. Patients undergoing a unicondylar knee replacement also seem to have a more favorable outcome in regard to certain functions like stair climbing or kneeling. Most studies suggest that patients with a successful unicondylar knee replacement recover range of motion faster and have better overall range of motion compared to patients undergoing total knee replacement.

Some of the advantages of a partial knee replacement include:

• Smaller incision
• No ligaments are cut
• Better-preserved range of motion as compared to total knee replacement
• Preserves healthy tissue and bone in the knee, promoting better knee function
• Reduced blood-loss during surgery
• Faster recovery because of the less-invasive nature of the surgery

Candidacy

• osteoarthritis in only one compartment of the knee joint may be eligible for a total knee replacement instead.
• Weight less than 100 kilograms
• Do not have significant deformity (bow-legged or knock-knee deformity of the knee)
• Rre still able to extend the knee to within 10 degrees of full extension (flexion contracture of less than 10 degrees)
• Are able to bend the knee more than 90 degrees
• Shouldn't have inflammatory arthritis

TKR Vs UKR

In TKR we replace all three compartments of knee joint.

On the contrary in UKR we replace only one compartment of your knee joint keeping other healthy compartments untouched.

When to do TKR?

Traditionally, total knee replacement (TKR) was commonly indicated for severe osteoarthritis of the knee where all these three compartments are severely damaged. In TKR all the compartments are treated with caps all over the joint surfaces.

When to do UKR?

But in some younger patients only the inner side of knee is severely damaged and fortunately other two compartments are healthy. In such patients only damaged medial compartment can be treated with Partial knee replacement (UKR) where metal caps are put only on inner side of your knee joint.

Compartments of knee joint

The knee can be divided into three compartments:

• Patellofemoral compartment: the compartment in front of the knee between the knee cap and thigh bone
• Medial compartment: the compartment which is on the inner side of the knee
• Lateral compartment: the compartment which is the outer portion of the knee joint