What is a Partial Knee Replacement?
Knee replacement is a surgical procedure that refers to either partial knee replacement or, more commonly, total knee replacement. This involves replacement of the worn bone and cartilage in an arthritic knee joint with metal and polyethylene surfaces that are implanted directly into the knee joint. The knee is thought of as having 3 different “compartments.” The medial (inner), lateral (outer) and patellofemoral (kneecap). In a “Partial” knee replacement, just one of these compartments is replaced as opposed to all 3 compartments in a traditional “Total” knee replacement.
Why Partial instead of Total Knee Replacement?
There are several advantages of a partial replacement. It is less invasive and typically done on an outpatient basis. The mechanics of the knee remain more natural and therefore allows patients to maintain a higher level of activity than with total knee replacement. Additionally, a conversion of a partial replacement to a total replacement is thought to be more straightforward than a complete “re-do” of a complete replacement.
Partial knee replacement is an option in patients who have arthritis confined to only one of the three compartments. Most patients with knee arthritis will have some degree of arthritis in 2 or more compartments which is why total knee replacement is more common than partial.
When Is Surgery Indicated?
Surgery is recommended for end stage osteoarthritis when all conservative treatments fail including but not limited to cortisone injections, viscosupplementation, physical therapy, bracing and activity modification. Some patients may be candidates for osteotomy surgery rather than knee replacement.
What Is The Typical Recovery?
This is done largely on an outpatient basis and we recommend a session of therapy the day of surgery to get you up and walking. Full weight-bearing is encouraged right away on the surgical knee, certainly this involves some mild discomfort. We expect that normal gait and low-level activities are quite comfortable within 4-6 weeks. Full recovery and return to all activities generally requires up to 3 months.