Prima Medical Group

Raymond Bonneau, M.D. Orthopedic Surgeon

165 Rowland Way, Suite 100
Novato, CA 94945
(415) 898-4211

Knee Replacement Background Information

  • Roughly 600,000 knee replacements are performed each year.
  • All total knee replacements consist of a four-part system: a metal tibial component, a metal femoral component, a plastic insert between them and a patellar component
  • A common issue with knee replacements is what surgeons refer to as “wear.” As the surfaces of the implant rub together, tiny fragments of plastic and metal material wear off.
  • Implant wear accounts for one reason why knee implants can fail, and why a patient may undergo repeat surgery years after the original procedure.
    • One recent study found that in a group of knee implants that were “revised” after an average of 7 years of use, 44% of the cases were the result of plastic wear.1
  • There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery.
  • Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable.
  • Early device failure, breakage or loosening may occur if you do not follow Dr. Bonneau's limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls.
  • Knee replacement surgery is intended to relieve knee pain and improve knee functions.
  • Talk to Dr. Bonneau to determine what treatment may be best for you.
  1. Sharkey et al. “Why are total knee arthroplasties failing today?” Clin orthop Relat Res, 404:7-13, 2002.