The knee has three compartments
Your knee has three compartments: the inner (medial), the outer (lateral), and the kneecap (patellofemoral). Arthritis can wear one compartment while leaving the others healthy. A total knee replacement resurfaces all three; a partial (unicompartmental) replacement resurfaces only the worn one, preserving the healthy cartilage and — importantly — the anterior cruciate ligament.
The case for partial knee replacement
For the right candidate, a partial knee replacement offers a smaller incision, less bone removal, a quicker early recovery, and a knee that often feels more 'natural' — because the preserved ligaments and compartments keep the knee's native motion pattern. Many partial knee patients are excellent candidates for outpatient surgery.
The requirements are strict: arthritis truly confined to one compartment, an intact ACL, good motion, and correctable alignment. Imaging and examination confirm candidacy — roughly speaking, only a minority of knee arthritis patients qualify.
The case for total knee replacement
When arthritis involves multiple compartments — the most common situation — total knee replacement is the reliable answer. Modern total knees, performed with quadriceps-sparing technique and alignment customized to your anatomy, deliver excellent pain relief and durability, with the large majority of implants lasting 15–20+ years.
Choosing a partial knee when arthritis is too widespread trades short-term appeal for a likely revision later, when the remaining compartments wear. That's why honest candidacy assessment matters more than preference.
Common Questions
Does a partial knee replacement last as long as a total?
Modern partial knees are durable, though revision rates run somewhat higher than total knees — partly because arthritis can progress in the untreated compartments. For well-selected patients, a partial knee can last decades.
Can a partial knee replacement be converted to a total later?
Yes. If arthritis progresses, a partial knee can be converted to a total knee replacement. The conversion is typically more straightforward than revising a total knee.
This guide provides general educational information and is not a substitute for individualized medical advice. Treatment decisions should always be made in consultation with your surgeon based on your specific anatomy, imaging, and health history.