Knee Replacement Surgery

by / Friday, 19 July 2019 / Published in Knee Pain, Orthopedic

Knee replacement surgery is one of the major breakthroughs of modern medicine. It was first performed in 1968, and since then several improvements in surgical materials and techniques increasing in overall safety and success rates. Approximately, 267,000 total knee replacements are performed each year in the United States.

The most common indications for knee replacement surgery include degenerative arthritis (with irreparable damage to the cartilage) and osteonecrosis (due to the compromised blood supply to the articular bone secondary to trauma).

Knee replacement surgery is considered when conventional/noninvasive medical management is no longer effective. Typical conservative management includes NSAIDs, steroids, lifestyle modification, walking supports, etc. But knee replacement surgery entails replacement of the knee’s damaged and worn-out articular surfaces.

It may take up to two months to walk properly without aids, and soon enough they resume activities such as bicycling, golfing, and swimming

The goal of knee replacement surgery is to treat pain and restore motion, and it is extremely effective at that. Approximately 90 percent of replacement joints last 10 years, while 80 percent is good for 20 years, but outcomes vary from patient to patient.

The procedure involves replacing the articular surfaces of the femur and tibia with metal/plastic covering surfaces so that the damaged irregular surfaces are covered by smooth. In most cases, the undersurface of the kneecap is also replaced with a plastic surface so that this articulates with the femoral surface. This procedure typically requires a three to six-day hospitalization. Post-operatively, weight bearing begins on day 1, and following the discharge, patients receive home health care, physical and occupational therapy. It may take up to two months to walk properly without aids, and soon enough they resume activities such as bicycling, golfing and swimming. However, participating in more rigorous sports such as skiing, basketball, and tennis will not be possible.

Partial knee replacement (also known as unicompartmental knee replacement) involves replacing only the part of the knee that is damaged or arthritic. The benefits of this approach include: less invasiveness, less bone removal, less pain, less blood loss, likely heal faster, and allow for a much easier transition to a total joint replacement if needed later.

The standard total knee replacement surgery can also be performed as a minimally invasive procedure, which also has the benefits of a smaller incision, faster healing, and better cosmetic results. Also, there is minimal trauma to the soft tissue, muscles, and tendons. The same types of joint prosthetics are used for this procedure as well, but they are precisely and carefully placed through the muscle and tendons. It requires a much shorter hospital stay (1-2 days) and the rehab period is also shorter with the patients returning to work and normal activities sooner as well.

Patients who receive a prosthetic knee implant may require revision surgery after several years. This is because of the general wear and tear that the prosthetic implant is subjected to over time. There is a lot of interest in using stem cell therapy to treat osteoarthritis, which if successful will greatly limit the need for knee replacement surgery, but the research is still at a very early stage.