ABOUT TAR

Ankle joint replacement has been performed in Europe since the 1970’s. Implants have been available in the United States since October of 1998. There are currently three FDA approved TAR implants: the Agility (DePuy), the InBone (Wright Medical), and the Salto-Talaris (Tornier). Dr Janis has extensive experience with all three. Due to the availability of multiple implants Dr. Janis is able to select the implant that is best for each individual patient.

Successes of Total Ankle Replacement

For an artificial joint to be successful, it must be able to withstand the pressures associated with weight-bearing and motion. Implants that are well-designed and properly implanted have a high success rate of 92 - 95 percent. Today almost everyone knows someone who has had a hip or knee replaced. Major advancements have taken place over the years to make them last longer with fewer complications. The same is true for the ankle joint replacement.

The Evolution of Total Ankle Replacement

Other treatment options:

Before ankle joint replacement was available, the only options for treating a painful ankle included anti-inflammatory medications, pain pills, braces, physical therapy, fusion or even amputation. All these options have significant drawbacks.

Pain control with medications:

Unfortunately, all drugs can have side effects. Anti-inflammatory pills such as aspirin and ibuprofen are hard on the stomach especially when used daily. Narcotic pain medicine relievers, such as codeine, can be addictive and habit forming. Ankle joint replacement can decrease the use of medications by relieving the cause of the pain.

Fusion:

Eliminating motion at the ankle joint, if successful, can get rid of pain. Ankle fusion is an operation that connects the shin bone (tibia) to the ankle bone (talus), making the foot and the leg essentially one piece. Unfortunately there is a 10 - 20% failure rate with this type of procedure. Even if the fusion is successful, there will be no motion at the ankle joint and you will often walk with a limp. Research shows that within five years after an ankle joint fusion other joints above and below the fusion can become arthritic and painful. This is due to the lack of motion at the ankle joint and the extra pressure or stress that is placed on the other joints (knee, hip and low back). Ankle joint replacement is available as an alternative to ankle fusion. In some cases a fused ankle can even be unfused and an ankle replacement inserted to create a normally functioning joint.

Amputation:

Pain in the ankle joint can be so severe and disabling that the patient would almost rather have their leg amputated than to live with the pain. While this used to be a consideration the disadvantages are certainly obvious. Fortunately, we now have treatment options that are much more reasonable than amputation.

Reasons for previous ankle joint design failures:

There have been numerous ankle joint replacements developed over the last 30 years. The ankle joint, although relatively small compared to a hip or knee joint, absorbs 4x the body's weight with every step. It is a very complex joint in that it really has three motions that occur all at the same time. Not only does it move up and down, but it also moves side-to-side, and rotates. Understanding the complexity of the ankle joint combined with new technology has allowed ankle joint replacement to advance to its present state of success.

The first implant designs had two different parts. One part was inserted into the tibia (shin bone) and the other fit into the talus (ankle bone). While it did allow for some up and down motion, it did restrict side-to-side and rotation motions, which was less than adequate in recreating normal ankle motion. The implants were also fixed into place with special bone cement. Eventually this cement would loosen around the implant and the bone, and the implant would fail.

The newer designed implants now have three pieces, two are metal, and one is plastic. One of the metal pieces is fit into the tibia (shin bone) and the other is fit into the talus (the ankle bone). The third piece is a special surgical grade plastic that acts as a bearing or washer between the two metal pieces. This allows for shock absorption as well as up and down motion, side- to-side motion and rotation. The plastic washer decreases friction inside the joint and limits wear and tear.

The newest generation of implants, are made of titanium. This metal has improved strength and has a porous coating that allows the bone to grow directly into the metal surface for increased stability. Therefore, cement is not necessary to hold the metal pieces in place.