Partial Knee Replacement (PKR): A Complete Guide

Introduction to Partial Knee Replacement (PKR)

Partial Knee Replacement (PKR), also known as unicompartmental knee replacement, is a minimally invasive surgical procedure designed to relieve pain and restore mobility in patients with arthritis or damage limited to one compartment of the knee. Unlike total knee replacement (TKR), PKR preserves healthy bone, ligaments, and cartilage, leading to a faster recovery and a more natural-feeling knee. Ideal for active individuals, PKR targets only the damaged area, making it a less invasive yet highly effective solution for knee pain. If you're struggling with knee discomfort but aren’t ready for a full replacement, PKR could be the right choice for you.

Who is a Candidate for PKR? (Eligibility Criteria)

Not everyone with knee pain qualifies for a Partial Knee Replacement. Ideal candidates typically have:

• Localized arthritis (only one part of the knee is damaged).
• Intact ligaments (especially the ACL).
• Stable knee alignment (no severe bowing or deformity).
• Healthy weight (BMI under 40 for better outcomes).
• No severe inflammation or infection in the knee.

Younger, active patients often prefer PKR because it allows for higher mobility post-surgery. However, if arthritis has spread to multiple knee compartments, a Total Knee Replacement (TKR) may be recommended instead.

How PKR Differs from Total Knee Replacement (TKR)

While both procedures aim to relieve knee pain, PKR and TKR have key differences:

• Less Invasive: PKR replaces only the damaged part of the knee, preserving healthy tissue.
• Smaller Incision: PKR requires a 3-4 inch cut vs. 8-10 inches for TKR.
• Faster Recovery: Most PKR patients walk within hours and recover in 4-6 weeks (vs. 3-6 months for TKR).
• More Natural Feel: Retaining ligaments and cartilage makes PKR feel closer to a natural knee.

However, PKR isn’t for everyone—if arthritis is widespread, TKR may be the better long-term solution.

The PKR Procedure: Step-by-Step Breakdown

Wondering what happens during a Partial Knee Replacement? Here’s a step-by-step overview:

1. Pre-Surgery Prep: You’ll undergo tests (X-rays, MRI) to confirm PKR is suitable.
2. Anesthesia: General or spinal anesthesia ensures you feel no pain.
3. Incision: A small cut (3-4 inches) is made over the knee.
4. Damaged Bone Removal: The surgeon trims only the diseased bone and cartilage.
5. Implant Placement: A metal and plastic prosthetic is secured in place.
6. Closure: Stitches or staples close the incision.

The surgery takes 1-2 hours, and many patients go home the same day!

Benefits and Advantages of Choosing PKR

Why do patients and surgeons prefer PKR when possible? Key benefits include:

• Faster Recovery: Return to daily activities in weeks, not months.
• Less Pain: Smaller incisions mean reduced post-op discomfort.
• Lower Risk of Complications: Fewer blood clots and infections vs. TKR.
• More Natural Movement: Preserved ligaments allow better knee function.
• Easier Revision (if needed): Converting PKR to TKR later is simpler.

For eligible patients, PKR offers a higher quality of life with minimal downtime.

Potential Risks and Complications

While PKR is generally safe, possible risks include:

• Infection: Rare but may require antibiotics or additional surgery.
• Blood Clots: Prevented with compression stockings and blood thinners.
• Implant Loosening/Wear: May need revision after 15-20 years.
• Persistent Pain: Some patients still experience mild discomfort.

Choosing an experienced surgeon and following post-op instructions reduces these risks significantly.

Recovery Timeline and Rehabilitation Tips

PKR recovery is quicker than TKR, but proper rehab is crucial:

• Day 1: Walk with assistance; start gentle exercises.
• Week 1-2: Use a walker/cane; focus on reducing swelling.
• Week 3-6: Physical therapy to restore strength and flexibility.
• Month 2-3: Resume low-impact activities (swimming, cycling).

Pro Tip: Avoid high-impact sports (running, basketball) for 6+ months to protect your new knee.

Long-Term Outcomes and Success Rates

Studies show PKR has excellent long-term results:

• 90-95% success rate at 10 years for eligible patients.
• 80-85% of PKR implants last 15+ years.
• Higher patient satisfaction vs. TKR due to better knee motion.

Factors like weight management and avoiding excessive strain can extend your PKR’s lifespan.

Frequently Asked Questions (FAQs) About PKR