Knee Replacement

Knee replacement, or knee arthroplasty, is a surgical procedure that replaces the weight-bearing surfaces of the knee joint to relieve the pain and disability of osteoarthritis. Dr. Lerner has an extensive background in joint replacement surgery, delivering excellent outcomes to his patients.

Total Knee Replacement: involves replacing the entire knee joint system.

The surgery exposes the front of the knee, detaching part of the quadriceps muscle (vastus medialis) from the patella. The patella is displaced to one side of the joint allowing exposure of the distal end of the femur and the proximal end of the tibia.

The ends of these bones are then accurately cut to shape using cutting guides oriented to the long axis of the bones. The cartilages and the anterior cruciate ligament are removed; the posterior cruciate ligament may also be removed but the tibial and fibular collateral ligaments are preserved.

Metal components are then impacted onto the bone or fixed using polymethylmethacrylate (PMMA) cement. A round-ended implant is used for the femur, mimicking the natural shape of the bone. On the tibia the component is flat, although it often has a stem that goes down inside the bone for further stability.

A flattened or slightly dished high-density polyethylene surface is then inserted onto the tibial component so that the weight is transferred metal to plastic not metal to metal.

During the operation any deformities must be corrected, and the ligaments balanced so that the knee has a good range of movement and is stable.

In some cases the articular surface of the patella is also removed and replaced by a polyethylene button cemented to the posterior surface of the patella. In other cases, the patella is replaced unaltered.

Partial Knee Replacement: also known as Unicompartmental Arthroplasty (UKA), is a minimally invasive procedure that involves the replacement of only one out of the three major components of the knee joint system.

The knee is generally divided into three main components: medial (the inside part of the knee), lateral (the outside), and patellofemoral (the joint between the kneecap and the thighbone).

Most patients with arthritis severe enough to consider knee replacement have significant wear in two or more of the above compartments and are best treated with total knee replacement.

A minority of patients have wear confined primarily to one compartment, usually the medial, and may be candidates for unicompartmental knee replacement. Advantages of UKA compared to TKA (Total Knee Arthroplasty, or Total Knee Replacement) include smaller incision, easier post-op rehabilitation, shorter hospital stay, less blood loss, lower risk of infection, stiffness, and blood clots, and easier revision if necessary.