Partial Knee Replacement

The knee is divided into three primary compartments:

Medial Compartment

The inside portion of the knee.

This is the most common location for arthritis and the area most frequently treated with partial knee replacement.

Lateral Compartment

The outside portion of the knee.

Partial replacement of this compartment is possible but generally less common.

Patellofemoral Compartment

The joint between the kneecap and the femur.

Patellofemoral replacements can be very successful in carefully selected patients but represent a much smaller percentage of cases.

While all three compartments can theoretically be treated with partial replacement, Dr. Tauchen believes the strongest and most predictable indications are typically found in patients with isolated medial compartment arthritis.

That is where he performs the vast majority of his partial knee replacements.

This is one of the most common questions patients ask.

The answer is simple.

If two-thirds of the knee remains healthy, why replace it?

Traditional total knee replacement removes the damaged portions of all compartments and substitutes them with artificial components.

A partial knee replacement takes a different approach.

Only the diseased compartment is resurfaced.

The healthy cartilage, ligaments, and bone in the remainder of the knee are preserved.

Most importantly, medial partial knee patients maintain:

• Their ACL
• Their PCL
• Their lateral compartment
• Much of their native bone
• Much of their natural knee anatomy

When only one portion of the knee is worn out, replacing only that portion often makes sense.

One of the biggest advantages of partial knee replacement is that many patients report the knee feels more normal than a total knee replacement.

There is a reason for that.

Because the ACL, PCL, and a large portion of native cartilage remain intact, the knee continues to function using many of the same mechanics it has relied upon throughout life.

The knee still rolls, glides, and moves using its native ligament structures.

This often leads to more natural knee kinematics.

“Kinematics” is simply a fancy way of describing how the knee moves.

When healthy structures remain in place, patients often experience:

• More natural motion
• Better proprioception
• Improved function
• Faster recovery
• Greater ability to forget the implant is there

No artificial knee can perfectly replicate the original knee.

However, preserving as much normal anatomy as possible often helps patients get remarkably close.

Partial knee replacement is an operation where precision matters.  A lot.

The implants are smaller than those used in total knee replacement, and the procedure requires careful balancing of the remaining native structures.  Many surgeons believe a partial knee replacement is more technically challenging to perform than a total knee replacement.

That is where Dr. Tauchen believes that the Mako robotic system becomes extremely valuable.

Before surgery, a CT scan creates a three-dimensional model of the patient’s knee.

This allows Dr. Tauchen to evaluate:

• Arthritis location
• Bone anatomy
• Implant sizing
• Alignment
• Ligament balance
• Component positioning

During surgery, the robotic system helps execute that plan with exceptional accuracy.

Think of it like building a custom home – You could probably get close using rough estimates, but why not use a laser level and precise measurements?

Both approaches may work, but one provides a much greater level of precision.

That precision becomes particularly important when preserving most of the knee and replacing only a small portion of it.

One of the reasons partial knee replacement has become increasingly popular is the quicker recovery.

Because less bone and tissue are being addressed, patients often experience:

• Less postoperative pain
• Faster recovery
• Earlier return to walking
• Improved early function
• Shorter rehabilitation

The majority of patients return home the same day.

Walking begins immediately after surgery.

Patients are often surprised by how quickly they regain confidence in the knee.

That does not mean recovery is effortless.

Surgery is still surgery.

However, many patients find the recovery process easier than they expected.

The ideal candidate is someone with arthritis isolated primarily to the medial compartment of the knee while maintaining healthy ligaments and relatively preserved cartilage elsewhere.

Not every patient qualifies.

Some patients have arthritis throughout the knee and are better served with total knee replacement.

Others may have ligament issues or patterns of arthritis that make partial replacement less predictable.

Determining candidacy requires careful evaluation, imaging, and discussion.

Many patients are relieved to learn that a less invasive option exists.

Dr. Tauchen has a special appreciation for partial knee replacement because it aligns closely with his overall philosophy of personalized joint replacement.

The goal is not simply to replace joints.

The goal is to restore function while preserving as much normal anatomy as possible.

When a patient has isolated medial compartment arthritis, a partial knee replacement allows him to address the painful portion of the knee while preserving healthy structures that are still doing their job.

Patients keep their ACL.

Patients keep their lateral compartment.

Patients keep much of the anatomy they were born with.

And in many cases, that translates into a knee that feels more natural than a traditional total knee replacement.

For the right patient, it can be one of the most rewarding operations in orthopedic surgery.

At the end of the day, the best joint replacement is often the one that allows patients to stop thinking about their joint altogether and get back to living their lives.