STAR Ankle Replacement

STAR ankle replacement at a glance

  • STAR stands for Scandinavian Total Ankle Replacement, which is an operation that replaces a damaged ankle joint with an artificial joint.
  • Ankle replacement, known as total ankle arthroplasty, is an option for patients needing relief from chronic ankle pain and is often used rather than ankle fusion surgery.
  • Implants such as the STAR ankle replacement can allow for greater range of motion than ankle fusion procedures.
  • Muir Orthopedics Specialists surgeons are experts at total ankle replacement and perform simple, complex, and revision cases.

What is STAR ankle replacement?

STAR is an acronym that stands for “Scandinavian Total Ankle Replacement.” This high-tech implant was developed for the purpose of replacing an ankle joint while still granting the patient a large range of motion upon recovery. STAR is a specific type of ankle replacement procedure, which is known as total ankle arthroplasty (TAA).

STAR is frequently recommended for patients seeking relief from ankle arthritis and chronic ankle pain. Ankle arthritis is not as common as it is in the knee or the hip, but can cause just as much pain and disability. It is most commonly seen after some history of trauma.

Traditionally, patients receiving ankle surgery to treat arthritis pain undergo a procedure called ankle fusion. Ankle fusion uses screws and plates to surgically join the bones of the ankle and leg.

While fusion is a proven method for pain relief, range of motion in the joint is drastically reduced by the procedure. Ankle fusion also greatly increases the risk of adjacent segment disease, a condition in which the joints surrounding the fused ankle become arthritic and painful as they compensate for the loss of motion in the fused area.

Alternatively, TAA fully replaces the ankle joint with a device that mimics the ankle’s natural range of motion. This preserves the joints surrounding the ankle from further arthritic damage and wear, and also gives the patient a higher chance of returning to physical activities with reduced pain and natural movement. In a number of ways, total ankle arthroplasty is superior to ankle fusion treatment, and STAR is on the leading edge of technology and success rates for total ankle replacement surgeries.

The video below illustrates the key differences between ankle fusion and Scandinavian Total Ankle Replacement.

What makes the STAR device unique?

When performing ankle replacement surgery, Muir Orthopaedic Specialists primarily uses the STAR device. Here are a few things that set STAR apart from other treatment options:

  • The STAR device uses a mobile bearing rather than the fixed bearing seen in other ankle replacement devices, allowing for more natural motion. Additionally, it does not require the use of bone cement.
  • After 10 years, STAR has a 90 percent survivability rate. This means that in 9 out of 10 cases, the device continues to function properly and without complication a decade after implantation.
  • The STAR joint is comprised of state-of-the-art, medical-grade materials that are generally well-accepted by the human body.

How does STAR work?

The STAR joint has three distinct components: A metallic piece that connects to the lower bone of the ankle joint (the talus), a mobile bearing that facilitates dynamic movement, and an upper metallic piece that connects to the shin (the tibia bone). The metallic components that actually make contact with the bones are coated with pure titanium.

STAR’s design is meant to replicate the fluid motion of a healthy ankle joint. In a well-functioning ankle, the region that joins the leg to the foot is facilitated by healthy cartilage and strong bones. Arthritis compromises bone strength and reduces the ability of the cartilage to provide cushioning and smooth, painless movement. The STAR joint replaces the damaged portions of ankle bone with strong metals, while the mobile bearing allows the joint to move in a dynamic fashion.

STAR implantation process

Most often, patients undergoing a STAR implant procedure receive general anesthesia. The surgeon inserts the STAR prosthetic joint by making an incision on the front of the patient’s ankle. The damaged portion of bone and cartilage is then removed, allowing the surgeon to carefully fit the implant to the patient’s ankle without the use of bone cement. Once the device is successfully implanted, the patient receives stitches to suture the incision, and the surrounding tendons are put back into place around the new joint.

Immediately following the surgery, patients usually spend at least one night in the hospital or rehabilitation center. The ankle is placed in a cast, brace or similar device to restrict movement. As healing continues, physical therapy may be advised.

After this period of recovery, patients return to enjoying non-impact activities such as walking, swimming and hiking. Each STAR recipient is advised by the orthopedic surgeon on the specifics of how to best facilitate the healing and recovery process.

Risks and considerations of ankle replacement and STAR

While the STAR device is a viable option for many patients seeking relief from the pain of ankle arthritis, it is important to note that it may not be a good fit for everyone. Ankle replacement technology is still being refined and developed and is not as advanced as hip and knee replacements. In the case of STAR and other forms of total ankle arthroplasty, it is possible that the prosthetic ankle will need to be replaced over time.

If any type of ankle replacement fails, fusion is the fallback solution. But that may be problematic because so much bone is removed in the ankle replacement that it makes the fusion procedure more difficult. Other risks of total ankle replacement such as STAR include:

  • Usual complications from any surgery such as blood clots, pain, tissue damage, infection, reaction to anesthesia and others
  • Fracturing of bones on either side of the ankle is the most common complication in TAA
  • Tendon, blood vessel and/or nerve injury
  • The prosthetic implant may fail to heal to the bone
  • Problems with wound healing for people who smoke or have diabetes
  • If an ankle has been fused previously, a prosthetic cannot be implanted
  • Bone/joint infection or any previous complications in the ankle region may be made more severe by an implant. It is important that the patient fully informs the surgeon of any prior or current ankle issues.

Studies have shown that 90 percent of STAR joints continue to operate normally after 10 years, however, no studies have been conducted that evaluate any prosthetic ankle beyond that time frame. STAR is not currently recommended for patients weighing more than 250 pounds. Overweight patients may be advised to lose weight prior to implantation.

To learn more about treatment options for ankle arthritis, contact us to schedule an appointment with one of our orthopedic specialists.