Our knowledge of orthopaedics. Your best health.

from the American Academy of Orthopaedic Surgeons

Diseases & Conditions



Staying Healthy

Total versus partial joint replacement: what are the differences?

Wayne Johnson

Wayne A. Johnson, MD

Any views or recommendations shared in the Ortho-pinions blog are solely those of the authors and do not necessarily represent those of the American Academy of Orthopaedic Surgeons.

Arthroplasty means the surgical repair of a joint. Orthopaedic surgeons performing an arthroplasty use metal and/or plastic parts to reconstruct degenerative, damaged, or arthritic joint surfaces in patients with severe arthritis who have failed nonsurgical treatment and have disabling function, limitation of activities of daily living, and severe pain.

Most joints are divided into two parts (e.g., the shoulder or hip joints), or three parts (e.g., the knee joint). Your knee is divided into three areas: medial (inside of your knee), lateral (outside of your knee) and patella (kneecap/front of your knee).

In a unicompartmental arthroplasty (partial knee replacement), your orthopaedic surgeon can replace just the damaged area of your knee. This enables you to keep more of your natural bone, tissue and ligaments when compared with a total knee replacement (replacing two or three knee surfaces). A partial knee replacement is less invasive, which may afford you a faster recovery, less time in the hospital (1-2 days for a partial joint replacement compared with 3-4 days for a total joint replacement), and a more active life than with a total knee replacement.

Only a small percentage of patients may qualify for a partial knee replacement. The vast majority of patients have two or more areas that are damaged or diseased. A total knee replacement will be the best solution for these patients.

The hip and shoulder are known as ball-and-socket joints. In patients who have failed nonoperative care, have arthritic or diseased hip or shoulder joints, disabling pain, diminished function, and diminution of their activities of daily living, hip or shoulder arthroplasty may be considered. Hip or shoulder arthroplasty involves removing the diseased or fractured ball and/or socket and replacing it with a metal ball attached to a stem (artificial joint or prosthesis) placed into the hollow center of the proximal femur (thighbone) or proximal humerus (upper arm bone) alone (partial joint replacement) or by adding an artificial plastic/metal cup placed in the hip or shoulder socket after the damaged cartilage has been removed (total joint replacement).

A partial replacement may be the best option for you after a fracture or if you have isolated arthritis or a diseased proximal femur or humerus with no involvement of the hip or shoulder socket. However, a total joint replacement would be a better option for patients with arthritis or disease involving the ball and socket of the hip or shoulder. Joint replacement surgery is also possible for the ankle, elbow, wrist, hand, feet and spine.

Learn more about Total Joint Replacement and Unicompartmental Knee Replacement.

This Ortho-pinion was originally written for A Nation in Motion, the AAOS's award-winning public awareness campaign dedicated to sharing the stories of people whose lives were improved by orthopaedic surgery.

Last Reviewed

March 2019

Contributed and/or Updated by

Wayne A. Johnson, MD

AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.