TOTAL KNEE REPLACEMENT 

ABOUT

A total knee replacement is a surgical procedure used to treat patients with moderate or severe, “bone on bone” osteoarthritis of knee. This is the joint surface between the “shin bone” (tibia) and the end of the “thigh bone” (femur), as well as between the “knee cap” (patella) and the femur. Total knee replacement is a complete resurfacing of the diseased surfaces of the knee joint, and replacement of the diseased surfaces of the knee joint with metal components and a polyethylene spacer.

WHO IS A CANDIDATE FOR A TOTAL KNEE REPLACEMENT (TKR)?

Patients who are candidates for a TKR are those with moderate-to-severe osteoarthritis of the knee, who have failed conservative/non-operative treatment.  These treatments include weight loss, physical therapy, braces, ambulatory aids, and anti-inflammatory oral therapy and Steroid or Hyaluronic Acid injection treatments. Patients with moderate-to-severe arthritis often present with symptoms of knee pain with activity with accompanying, swelling, stiffness, and decreased mobility that may improve with rest or lessened activity. Patients may also experience a crunching or grinding sensation when the knee moves. Total knee replacements are most commonly performed in patients age 50 and older. We do, however, perform this procedure in younger patient populations based on medical necessity. In order to determine whether or not you are a candidate for a TKR, your surgeon will first obtain plain x-rays to assess areas of bone on bone osteoarthritis. Your surgeon may then have you get an MRI to evaluate all other parts of your knee.

WHAT IS A CUSTOM TOTAL KNEE REPLACEMENT? IS IT NECESSARY?

Although knee replacement surgery is highly successful and durable, patient dissatisfaction has been reported to be anywhere from 20-25%. Complaints include the sensation that the knee feels “Fake”, moves unnaturally, feels tight and stiff, and may have residual pain.

 

This is not too surprising when you consider that the knee is an asymmetric joint and the standard “Off the Shelf” (OTS) replacements are symmetric, and only in certain sizes. The surgeon must shape the bones to the closest size fit of the implant available and loosen the soft tissues that are tight to “Balance” the soft tissues around the knee. If the OTS implant is a close fit and the soft tissues are balanced well, the patient will do well. Much like an “Off the Rack” suit fitting average size people but failing to fit well for very small or large people as opposed to a “Bespoke” Custom Tailored suit which always fits well. Custom made implants use 21st century technology now only available because of enhanced computer speeds, software development and ‘Printing’ technology.

 

A custom made knee replacement is individualized to only one patient. A CT scan is taken of the entire affected leg to allow software engineers to ‘Print’ individualized Jigs for the surgery to restore the leg to be straight and not ‘Knock Kneed’ or ‘Bow Legged’.

 

The software engineers then use the images of the knee to restore the exact shape of the knee before it became arthritic and print individualized molds from which the knee is then made precisely to fit that individual patient and no one else.

 

As the knee has 2 weight bearing surfaces at different levels from each other, 2 plastic inserts are made to restore the exact joint line level as the patient originally had. These plastic inserts use Vitamin E infusion patented technology that has a 40% improved wear rate over standard plastic inserts. As a result of restoring the original form leads to better movement, function and satisfaction.

 

Other benefits to custom total knee replacement:

  • Thinner implants with 40% less bone removed

  • Less bleeding

  • Excellent return of motion earlier

  • Patient satisfaction has improved from 80+% to mid-90%

Software Engineers depiction of an exact fit, asymmetric,

Individualized custom-made knee replacement

Custom Made Knee Replacement made from Printed Molds as an Exact fit to

a patient’s knee and restoring their joint surfaces precisely to what they originally were.

(Made from Cobalt Chrome metal and Vitamin E infused polyethylene)

Femoral Component (Cobalt Chrome)

Articulating Surface (Polyethylene)

Stemmed Tibial Plate (Cobalt Chrome)

Stem

Paley Orthopedic & Spine Institute, 901 45th Street, Kimmel Building,  West Palm Beach, FL 33407   561-844-5255