Total vs Partial Knee Replacement

Total Knee Replacement (TKA)

Total knee replacement removes the entire damaged joint surface and replaces it with metal and plastic components. The surgeon resurfaces the end of the femur (thighbone), top of the tibia (shinbone), and often the underside of the kneecap. TKA is the most common joint replacement surgery in the US — over 700,000 performed annually. Best for: Advanced arthritis affecting the entire knee, patients over 60, severe pain not responding to conservative treatment. Recovery: Walking same day, 3-6 weeks on walker, 3 months for most activities, 6-12 months full recovery. Implants last 20-25 years.

Partial Knee Replacement (UKA)

Partial knee replacement (unicompartmental knee arthroplasty) replaces only the damaged compartment of the knee — either the inner (medial), outer (lateral), or kneecap (patellofemoral). The healthy portions of the joint are preserved. Best for: Arthritis limited to one compartment, intact ligaments (especially ACL), younger/active patients, BMI under 35. Recovery: Faster than total — most patients walk without a cane in 2-3 weeks. Smaller incision, less bone removal, more natural-feeling knee. However, may need conversion to total knee later.

Key Differences

Factor	Total Knee	Partial Knee
Hospital stay	1-2 days	Often same-day
Recovery to daily activities	3 months	4-6 weeks
Cost (before insurance)	$30,000-$70,000	$20,000-$45,000
Implant lifespan	20-25 years	15-20 years
Revision rate (10yr)	3-5%	5-10%
Knee feels natural?	Good but different	More natural
Who qualifies?	Almost anyone	Only single-compartment arthritis

Which Should You Choose?

Your surgeon will recommend based on imaging (X-rays/MRI), physical exam, and your goals. If arthritis affects only one compartment and your ligaments are intact, partial may preserve more natural knee function. If arthritis is widespread, total replacement provides the most reliable long-term result. Get a second opinion — not all surgeons offer both options.

Frequently Asked Questions

Is partial knee replacement less painful?

Generally yes. Partial knee replacement has a smaller incision, less bone removal, and preserves healthy tissue. Most patients report less post-operative pain and faster recovery than total knee replacement.

Can a partial knee be converted to a total later?

Yes. If arthritis progresses to other compartments, a partial knee can be revised to a total knee replacement. This is a more complex surgery than a primary total knee but has good outcomes.

How do I know if I qualify for partial knee replacement?

You need: arthritis limited to one compartment, an intact ACL, good range of motion (at least 90 degrees), and minimal deformity. Your surgeon will determine candidacy based on imaging and exam.

Which lasts longer — total or partial?

Total knee replacements have a slightly longer track record (20-25 years) compared to partial (15-20 years). However, if a partial fails, it can be revised to a total.

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