Partial Knee Replacement

Partial Knee Replacement

Partial Knee Replacement

During knee replacement surgery, damaged bone and cartilage is resurfaced with metal and plastic components. In unicompartmental knee replacement (also called “partial” knee replacement) only a portion of the knee is resurfaced. This procedure is an alternative to total knee replacement for patients whose disease is limited to just one area of the knee.


Because a partial knee replacement is done through a smaller incision, patients usually spend less time in the hospital and return to normal activities sooner than total knee replacement patients.


In knee osteoarthritis, the cartilage protecting the bones of the knee slowly wears away. This can occur throughout the knee joint or just in a single area of the knee.


Your knee is divided into three major compartments:

  • Medial compartment (the inside part of the knee)
  • Lateral compartment (the outside part)
  • Patellofemoral compartment (the front of the knee between the kneecap and thighbone)


Advanced osteoarthritis that is limited to a single compartment may be treated with a unicompartmental knee replacement. During this procedure, the damaged compartment is replaced with metal and plastic. The healthy cartilage and bone, as well as all of the ligaments are preserved.

In unicompartmental knee replacement, only one area of the knee is resurfaced.

Advantages of Partial Knee Replacement

Multiple studies show that a majority of patients who are appropriate candidates for the procedure have good results with unicompartmental knee replacement.


The advantages of partial knee replacement over total knee replacement include:

  • Quicker recovery
  • Less pain after surgery
  • Less blood loss


Also, because the bone, cartilage, and ligaments in the healthy parts of the knee are kept, many patients report that a unicompartmental knee replacement feels more natural than a total knee replacement. A unicompartmental knee may also bend better.


Disadvantages of Partial Knee Replacement


The disadvantages of partial knee replacement compared with total knee replacement include:

  • Slightly less predictable pain relief
  • Potential need for more surgery. For example, a total knee replacement may be necessary in the future if arthritis develops in the parts of the knee that have not been replaced.

Dr. Alosh, MD is board-certified and fellowship-trained in minimally invasive joint reconstruction.  He specializes in minimally invasive partial knee replacement and has obtained advanced training in the most contemporary techniques.  This incision is smaller, the major ligaments are preserved, and the knee cap is gently shifted to the side rather than flipped into an unnatural position.  Regardless of where you are considering knee replacement, we strongly advise that you obtain a consultation with a board certified, fellowship-trained MD with advanced training in adult reconstruction.  No one’s knee deserves mediocre surgery.

(Left) A normal knee joint: The medial, lateral, and patellofemoral compartments are shown with red arrows. (Right) An x-ray of a normal knee joint showing healthy space between the bones.

(Left) Osteoarthritis that is limited to the medial compartment. (Right) This x-ray shows severe osteoarthritis with “bone-on-bone” degeneration in the medial compartment (arrow).

An advantage of partial knee replacement over total knee replacement is that healthy parts of the knee are preserved, which helps to maintain more “natural” function of the knee.

Minimally invasive knee replacement

Average knee replacement

  • Dr. Alosh is a board-certified MD
  • All education at top 10 US hospitals
  • Fellowship-trained and specialized in minimally invasive joint reconstruction
  • Questionable board certification
  • Variable training background
  • “Dabble” in joint replacement
Experience Dr. Alosh has performed over a 1000 replacements using the latest techniques and advances Broad range of quality: Some surgeons dabble and only perform a couple replacements a year. Some high-volume surgeons still use old techniques.
Knee dislocation Dr. Alosh does not dislocate the knee to perform the operation Traditional surgeons aggressively dislocate (separate) the knee to obtain access
Knee cap Dr. Alosh gently shifts the knee cap to the side Traditional surgeons flip over and dislocate knee cap increasing trauma
Blood loss Minimal, less than 50ml 200-300ml
Recovery Most patients discharge the next day, some the same day In hospital for 3 days