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Knee Anatomy: Only replace what is damaged

The knee joint is the point at which the femur bone of the thigh meets the tibia bone of the lower leg. All the components of the knee - bones, cartilage, synovial membrane, ligaments, tendons and muscles - must work together properly for the knee to move smoothly.

Cartilage is a protective cushioning that keeps the bones from rubbing against one another.

In a healthy knee, a thin, smooth tissue liner called the synovial membrane releases a fluid that lubricates the knee, reducing friction as the bones move. In an arthritic knee, the cartilage between the femur (thigh bone) and the tibia (shin bone) gets worn away, causing the two bones to scrape against each other. When this happens, the joint can become pitted, eroded and uneven, often resulting in pain, stiffness and instability. While this type of arthritis damage often happens throughout the entire joint, for some patients it can be localized in a single compartment of the knee. If the damage is localized to a single compartment, treatment with partial knee replacement may be an option.

Because partial knee implants only replace the damaged bone and cartilage of the medial, lateral or patellofemoral compartment of your knee, the rest your natural knee's structure is retained.

Potential Benefits Of Partial Knee Replacement Compared with Total Knee Replacement

(Results may vary)

  • No disruption of the knee cap1
  • Less blood loss2
  • Possibility for less post-operative pain2
  • Faster rehab/recovery time2
  • Better range of motion3

Important Safety Notes:

Knee replacement surgery is intended to relieve knee pain and improve knee function. There are potential risks with knee replacement surgery such as loosening, wear and infection that may result in the need for additional surgery. For more information on the risks associated with total knee replacement surgery, please review the information found on the Knee Replacement Indications For Use page.

Talk to your doctor to determine what treatment may be best for you.

1Based on ZUK surgical technique
3 Laurencin CT, Zelicof SB, Scott RD, Ewald FC. Unicompartmental versus total knee arthroplasty in the same patient. A comparative study. Clin Orthop Relat Res. 1991; (273):151-156

All information provided on this website is for information purposes only. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation. If you are seeking this information in an emergency situation, please call 911 and seek emergency help.
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  • Arthritis Foundation
  • UIC Education
  • AAOS
  • Stanford University
  • New England Baptist Hospital