Am I a candidate for a partial knee replacement?

Partial knee and total/full knee replacements are different ways of surgically treating knee arthritis with replacement surgery. There are three main compartments in the knee: the medial (inside of the knee), the lateral (outside of the knee), and the patellofemoral compartments (under the knee cap). When arthritis is limited to just one part of the knee, a partial knee replacement is an option (as is a total knee placement).

Partial knee replacement

  A partial knee replacement can be performed when arthritis and pain in the knee is limited to one compartment. People with arthritis in just one compartment of the knee will often be able to point to one spot in the knee as the source of their pain. X-rays will confirm that the arthritis is limited to one part of the knee. 

                  A partial knee replacement replaces just one compartment and is in essence one third of a total knee replacement surgery. As such, the rehabilitation from a partial knee replacement is quicker as a partial knee replacement more closely approximates a normal knee than a total knee replacement does. However, partial knees can fail and one of the most common reasons for failure of partial knee replacements is progression of arthritis in the other parts of the knee. This would usually necessitate a conversion to a total knee replacement. 

Total knee replacement

  A total knee replacement is performed when arthritis is in more than one compartment in the knee. This can be confirmed with x-rays. A total knee replacement is also an option when arthritis is limited to just one compartment. 

                A total knee replacement involves replacing at least two compartments in the knee (medial and lateral); it can involve replacing all three compartments (medial, lateral, and patellofemoral). As such, a total knee replacement involves more surgery than a partial knee replacement. The rehabilitation from a total knee replacement can be more involved and longer than the rehabilitation from a partial knee replacement. Nevertheless, total knee replacements are more reliable with longer lasting implants than partial knee replacements. Total knee replacements continue to show a slightly lower rate of failure compared to partial knee replacements and a lower revision/re-do rate. 

Partial versus total knee replacement

  About 10% of knee replacements performed in the United States are partial knee replacements. Both surgeries can provide good outcomes and satisfaction when expectations are appropriately set in properly selected patients. An important point to remember is that a partial knee replacement is an option for surgically managing knee arthritis but not everyone would be a good candidate for a partial knee replacement when compared to a total knee replacement.