I have a unicompartmental knee replacement in the left knee. The operation was done with an open incision. Now I need the same operation on the right knee. But a different surgeon is going to do it using a much smaller incision. Is this something new?

More and more surgeons are now using the minimally invasive surgery (MIS) for unicompartmental (one side) and total knee replacements (TKRs). This new technique has been made possible by advances in technology and surgical instruments.

The MIS method was actually developed for unicompartmental knee arthroplasty (UKA). It was later adapted for use with TKRs. With MIS, there is the obvious advantage of a smaller scar for the patient. But this also means less soft tissue and muscle is cut making rehab and recovery faster and easier.

Other advantages of the MIS are less blood loss, less pain, and lower costs. There are some concerns about the accuracy of implant position with a shorter incision. But improved computer navigation may offset this problem.

So far, several studies have shown no difference in the accuracy of implant alignment between these two surgical procedures. It's likely that more and more surgeons will move from the traditional open incision method to the MIS method.