When I saw the surgeon about my knee replacement, she advised using a unicompartmental implant. She will just remove and replace the inside half of my left knee. The paperwork I was given says that this type of surgery is less invasive. What does that mean?

Improved technology and surgical equipment has made it possible for surgeons to perform some operations with smaller incisions. This is called minimally invasive surgery (MIS).

A smaller incision also means less damage to the soft tissues and muscles. In the case of knee replacement surgery, the ligaments inside the knee and the quadriceps muscle along the front of the thigh are spared during MIS.

Studies show that preserving the integrity of the soft tissues also maintains more normal knee function. Proprioception and kinematics remain normal or near normal. Proprioception refers to the joint’s sense of position. Kinematics is the actual motion of the joint.

Patients end up with a more functional knee after UKA compared with a total knee replacement (TKR) that is done with the standard, open incision approach. The UKA patients can put more weight on the leg sooner. They return to full activities faster.

Studies show these positive results are likely the result of preserving normal biomechanics and kinematics in knees after UKA implantation.