Orthopedist Questions Joint Replacement

partial vs full joint replacment

What is the difference between a partial and a full joint replacement? Does a partial one have to be done again later?

18 Answers

A joint has two parts. In a total replacement both are replaced. In a partial only one side of the joint is replaced. They usually do not have to be redone.
A partial knee replacement can only be done if there is arthritis in only one part of the knee. If there is arthritis in two or more compartments in the knee then a total knee replacement will be needed. If the partial knee replacement is indicated and done a total knee replacement will need to be done sometime in the future.
Typically a partial joint replacement only replaces a portion of the joint where as a full joint replacement would replace both sides of the joint. Typically each is chosen based on what is needed to give the best outcome.
Sometimes only part of the joint is arthritic and that can be treated with a partial joint replacement.
A partial replacement just replaces one side of the joint whereas a full replacement replaces both sides of the joint. Frequently especially in the hip partial replacements need further surgery. Partial knee replacements have a better record for lasting longer.
Depends on existing conditions.
More reliability and success with total.
Partial and Total joint replacements refer to the amount of the joint that is removed and replaced with the new metal and plastic implants. The usual determining factor is how much of the joint is damaged, which will determine how much of the joint needs to be replaced. In general, you only want to replace the portion of the joint that is not functioning well. The longevity of the implants and the surgical outcomes can be dependent on several factors including the type of implant, the positioning of the implant surgically and the use of the implant after surgery.
A total knee replacement involves replacing all 3 compartments of the knee - medial (inside), lateral (outside) & patellofemoral (kneecap). A partial knee replacement involves replacing only one of these compartments - either the medial or the lateral or the patellofemoral.

If there is significant arthritis in more than 1 compartment of the knee, then a partial is not an option-it must be a total knee replacement. Traditionally, the ACL & often the PCL are cut out and “replaced” in a total knee replacement. The knee tends to feel “artificial”. These ligaments are preserved in a partial knee replacement. The knee feels more like a “normal” knee because of the preservation of these ligaments.

There is a small risk of needing additional surgery in a partial knee replacement if arthritis develops in the other compartments of the knee. This would require the partial being converted to a total knee replacement. If this does occur, it is usually possible to convert the partial to a total knee replacement using the same type of knee prosthesis that would be used in a normal total knee replacement (i.e. able to use primary knee replacement components...no need for revision knee replacement components). Patient satisfaction is high after total, partial and even conversion surgeries.

Steven M. DeLuca, DO
Your knee consist of three distinct compartments; the inner side (medial), the outer side (lateral) and the kneecap (patella). Arthritis can affect all three compartments and if it does, you need all the compartments replaced and this is a full knee replacement. If only one compartment has arthritis and the knee is otherwise healthy, you may be a candidate for a partial replacement. Partial knee replacements are not performed as stop gap measures to "buy you time to a full knee", they are performed as end line operations just like a full or total knee replacement. If however, future surgery needs to be performed on a partial knee for wearing or loosening, this second operation is relatively easy as compared to a second procedure on a full knee.
Which joint are you asking about?
A partial knee replacement is done when only one of the three parts of a knee has arthritis. They last 8-10 years and then are converted to a total knee. Total knees are done when there is arthritis in 2 or more parts of the knee.

Dr. Bose
Knee consist of three compartments, if all three replaced is called full joint replacement, if one is done called partial.
Due to fact partial is very technically very demanding most need to be converted to total replacement. Those that needs Partial can be managed with brace or high tibial osteotomy and avoid partial.
Based on your X-rays findings
The knee has three compartments. A partial replacement only resurfaces one compartment. A total replacement resurfaces all three compartments. With a partial replacement the other compartments can become affected by arthritis over time. This then requires a conversion of the partial to a total knee replacement.
A partial joint replacement means that only one side of the joint is being replaced-- such as the medial or lateral side. A full joint replacement means that a full joint is being replaced. A partial replacement doesn't necessarily need to be done again, it depends on the age of the patient.
A partial knee is done for patients who only have arthritis in one compartment in their knee. When these are performed, it is not done with intention to do a total knee later. Partial knees usually last longer than whole knee replacements...15-25 years or longer. when whole knees or partial knee replacements wear out or fail, then a new whole knee must be put in.
Fewer Knee Arthrtis patients are partial candidates. Those who are have very high satisfaction results but higher less than 10 year and 20 year reoperation rates. A simple squat test wherein the patient points with one finger to the only painful part of the knee (like medial) is best selected for possible partial.