Patellar Resurfacing in Total Knee Replacement: What You Need to Know

When you get a knee replacement, your surgeon must decide whether to resurface your kneecap (patella) with a plastic component or leave it natural. This choice depends on how damaged your kneecap cartilage is, your bone quality, and several other factors. Both approaches can work well with modern implants. The key is matching the right technique to your specific situation. This guide explains how surgeons make this decision and what it means for your recovery.

Understanding Your Kneecap in Knee Replacement Surgery

Your kneecap sits in a groove on the front of your thighbone. When you bend and straighten your knee, it slides up and down in that groove. The back of your kneecap is covered with cartilage, just like the other joint surfaces in your knee. When arthritis damages this cartilage, you feel pain in the front of your knee. This happens most when you climb stairs, kneel, or get up from a chair. That's because these activities put extra pressure on your kneecap joint. During total knee replacement, surgeons replace the damaged surfaces of your thighbone and shinbone with metal and plastic components. But what about the kneecap? That's where the debate begins.

The Three Approaches Surgeons Use

Think of patellar management like choosing the right tool for a job. There are three main philosophies:

Always resurface. Some surgeons replace the kneecap cartilage in every knee replacement. They believe this prevents future kneecap pain and gives the most predictable results.

Never resurface. Other surgeons prefer to leave the kneecap alone if possible. They point to modern knee implants that work well with natural kneecaps and avoid potential complications from resurfacing.

Selective resurfacing. Many surgeons, myself included, take a middle path. We look at your specific kneecap during surgery and decide based on what we see. This personalized approach has become more popular with better implant designs.

How Patellar Resurfacing Works

If your surgeon decides to resurface your kneecap, here's what happens.

The Surgical Technique

First, we move your kneecap to the side so we can see the back surface clearly. We remove any bone spurs around the edges. Then comes the critical part. We use a special saw to cut away the damaged cartilage and a thin layer of bone. The goal is to create a flat surface. This step requires precision. We need to remove enough bone to fit the plastic component, but not so much that the kneecap becomes weak. Most surgeons aim to keep at least 12 to 15 millimeters of bone. That's roughly half an inch. Any thinner, and your risk of fracture goes up.

Choosing the Right Component

The replacement piece is made of medical-grade plastic. It looks like a small dome or button with three pegs on the back. These pegs fit into holes we drill in your kneecap bone. Size matters here. The component needs to cover the cut bone surface without hanging over the edges. Overhang can cause pain and irritation. We also position it slightly toward the inside of your kneecap to help with tracking. Finally, we use bone cement to lock everything in place. The cement bonds the plastic to your bone and hardens in minutes.

What Happens to the Lateral Facet

There's one more technical detail worth knowing. The outside edge of your kneecap (the lateral facet) sometimes needs trimming. We call this a lateral facetectomy. This step helps your kneecap track smoothly in its groove. Without it, some patients feel clicking or catching. It's a small detail that can make a big difference in how your knee feels.

When Resurfacing Makes Sense

Not every kneecap needs resurfacing. Here's when it typically helps.

Signs Your Kneecap Should Be Resurfaced

• You have severe kneecap arthritis that shows on X-rays. The cartilage is worn down to bare bone, creating rough, irregular surfaces.
• You feel significant pain in the front of your knee before surgery. This pain gets worse when you use stairs or squat down.
• You have inflammatory arthritis like rheumatoid arthritis or psoriatic arthritis. These conditions damage kneecap cartilage more aggressively than regular osteoarthritis.
• Your kneecap is thick enough. We measure this before cutting. If you start with a thin kneecap (less than 20 millimeters), resurfacing becomes riskier.

Patient Factors That Matter

Your weight plays a role. Heavier patients put more force through their kneecaps. Some research suggests they do better with resurfacing, though results vary. Age matters too. Younger, more active patients might benefit from resurfacing because they'll put more demand on their knees over the years. If you've had previous knee surgery, that can affect the decision. Prior arthroscopy or other procedures might have damaged kneecap cartilage that looked okay on X-rays.

The Case for Not Resurfacing

Leaving your kneecap natural has real advantages in the right situation.

Benefits of Keeping Your Natural Kneecap

You avoid specific complications tied to resurfacing. These include kneecap fracture, loosening of the plastic component, and problems with the kneecap tracking properly. Surgery takes less time. That means less anesthesia exposure and potentially faster recovery. You keep your own bone and cartilage. If the cartilage isn't badly damaged, why replace it?

Modern Implants Change the Game

Today's knee replacement implants work better with natural kneecaps than older designs. The groove on the front of the metal component is deeper and shaped more like your natural anatomy. This means your kneecap glides more smoothly even without resurfacing. Twenty years ago, this wasn't the case. Older implants had shallow grooves that didn't accommodate natural kneecaps well. Several large studies comparing resurfaced and non-resurfaced kneecaps show similar pain relief and function scores with modern implants. The gap has narrowed significantly.

Who Does Well Without Resurfacing

• Your kneecap cartilage looks relatively healthy during surgery. Sure, it has some wear, but not bone-on-bone damage.
• You don't have much kneecap pain before surgery. Your main problem is pain on the inside or outside of your knee, not the front.
• Your kneecap tracks straight in its groove when we test it during surgery. It doesn't tilt or slide to one side.
• You have good bone quality. Osteoporosis or very soft bone makes resurfacing riskier.

Potential Complications and Risks

Every surgical decision involves tradeoffs. Let's talk about what can go wrong with each approach.

Risks of Patellar Resurfacing

• Kneecap fracture is the most serious complication. It happens when we remove too much bone or the remaining bone is weak. The fracture rate is low with proper technique, usually under 1%, but it's a problem that often needs more surgery.
• Component loosening occurs when the plastic button separates from the bone. You'll feel grinding, pain, and instability. This also typically requires revision surgery.
• Maltracking means your kneecap doesn't move smoothly in its groove. It can tilt to one side or even dislocate. This causes pain and a feeling that your knee might give out.
• Overstuffing the joint happens if we don't remove enough bone to account for the plastic component's thickness. Your kneecap ends up sitting too far forward. This limits how much you can bend your knee and creates a tight, uncomfortable feeling.

Risks of Not Resurfacing

The main risk is persistent front knee pain. Some patients continue having pain in the kneecap area even after successful knee replacement. This happens because the damaged cartilage is still there, rubbing against the metal implant. Studies show that about 5 to 10% of patients with non-resurfaced kneecaps need secondary resurfacing later. That means another surgery to add the plastic component. The good news? This secondary surgery usually works well. Patients who get it typically see their pain improve. But it's still another operation with additional recovery time.

Comparing the Numbers

Large registry studies tracking thousands of knee replacements show interesting patterns. Resurfaced kneecaps have slightly higher early complication rates (fractures, loosening in the first few years). Non-resurfaced kneecaps have a slightly higher rate of reoperation over time (for secondary resurfacing). At 10 years, the overall revision rates are similar between the two approaches when modern implants are used. What matters most is matching the technique to the patient.

What Recovery Looks Like

Your kneecap management doesn't dramatically change your initial recovery, but there are some differences worth knowing.

The First Few Weeks

Whether your kneecap is resurfaced or not, you'll follow similar rehabilitation protocols. You'll start physical therapy within a day or two of surgery. The focus is on regaining motion and building strength. Pain levels are comparable between resurfaced and non-resurfaced knees in most patients. You'll have discomfort for several weeks as your body heals. Pain medication helps during this period. Some patients with resurfaced kneecaps notice more sensitivity around the kneecap itself. This usually improves within the first month.

Long-Term Expectations

By three to six months, most patients can't tell whether their kneecap was resurfaced or not. Both groups report similar satisfaction levels and ability to return to daily activities. Kneeling comfort varies between patients regardless of resurfacing. Some people kneel easily after knee replacement. Others find it uncomfortable. The resurfacing decision doesn't predict this reliably. Stair climbing should improve either way. That's one of the main goals of knee replacement surgery. If you're still having significant pain going up and down stairs months after surgery, something else might be wrong. Tell your surgeon.

Making the Decision With Your Surgeon

Here's what I tell patients when we discuss their upcoming knee replacement.

Questions to Ask

• What does my kneecap look like on X-rays? Ask to see the images. Your surgeon can show you how much cartilage damage exists.
• What's your usual approach to the kneecap? Understanding your surgeon's philosophy helps you know what to expect. There's no single right answer, but you should know their reasoning.
• What type of knee implant will you use? Some implants work better with natural kneecaps than others. Your surgeon should be familiar with how their chosen implant performs both ways.
• What happens if I need secondary resurfacing later? Knowing this is an option can ease concerns about leaving the kneecap natural.

Trust the Intraoperative Assessment

Even if you and your surgeon lean one way before surgery, the final decision often happens when you're asleep on the operating table. That's when we can directly see and feel your kneecap cartilage. We can test how your kneecap tracks. We can measure bone thickness precisely. We can assess cartilage quality in ways that X-rays and MRI scans can't show. This intraoperative flexibility is why selective resurfacing has become popular. It lets us use all available information to make the best choice for your specific knee.

Living With Your Decision

Once you recover from surgery, the resurfacing decision fades into the background. Most patients focus on what they can do, not on the details of their implant.

Activities You Can Enjoy

Walking, biking, swimming, and golf are all great activities after knee replacement. These put reasonable loads on your kneecap regardless of whether it's resurfaced. Light hiking on even terrain works well too. Many patients return to recreational activities they couldn't do before surgery because of knee pain.

Activities to Approach Carefully

Running and jumping create high forces on your kneecap. Most surgeons suggest avoiding these regardless of resurfacing. The risk isn't worth it for the longevity of your knee replacement. High-impact sports like basketball and tennis put excessive stress on all components of your knee replacement, including the kneecap. Consider lower-impact alternatives that still keep you active. Contact sports are generally off the table after knee replacement. The risk of injury to your artificial knee is too high.

Key Takeaways for Patients

• Patellar resurfacing is neither always necessary nor always wrong. The best approach depends on your specific situation.
• Modern knee implants perform well with both resurfaced and natural kneecaps when the decision is made thoughtfully.
• Trust your surgeon's expertise, but don't hesitate to ask questions. Understanding the reasoning behind their recommendation helps you feel confident in your care.
• If you have severe kneecap arthritis with significant pain, resurfacing usually makes sense. If your kneecap cartilage is relatively preserved, leaving it natural is reasonable.
• Either way, successful knee replacement can dramatically improve your quality of life. The goal is pain relief and return to activities you enjoy. Most patients achieve this regardless of how their kneecap is managed.

When to Call Your Surgeon After Surgery

Certain symptoms after knee replacement need prompt attention, whether your kneecap was resurfaced or not.

Sudden sharp pain in the front of your knee, especially after a fall or twist, could indicate a kneecap fracture. This requires immediate evaluation.

A feeling that your kneecap is sliding out of place or dislocating is not normal. Contact your surgeon's office right away.

Persistent pain in the front of your knee that doesn't improve over several months might indicate a problem with kneecap tracking or other issues. Don't wait months before bringing this up.

Any signs of infection (increasing redness, warmth, drainage, fever) require urgent medical attention. This applies to all knee replacements regardless of the surgical details.

Considering knee replacement surgery in Middle Tennessee? Dr. Cory Calendine provides advanced total knee replacement surgery with personalized patellar management strategies at his practice serving Franklin, Brentwood, and surrounding communities. With extensive experience in both traditional and modern knee replacement techniques, Dr. Calendine carefully evaluates each patient's unique anatomy and arthritis patterns to determine the optimal surgical approach. His practice emphasizes evidence-based care combined with individualized treatment plans to help patients achieve the best possible outcomes. If you're struggling with knee arthritis and want to explore your options, schedule a consultation to discuss whether knee replacement might be right for you. Dr. Calendine and his team are committed to helping patients in the Nashville area regain mobility and return to the activities they love. Contact our office today.

This article is for educational purposes only and should not replace professional medical advice. Every patient's situation is unique. Consult with a qualified orthopedic surgeon to discuss your specific condition and treatment options.