I’m doing some looking on-line about stress fractures and how they should be treated. My situation is a little bit more complicated than a simple stress fracture because I have an ankle joint replacement and the fracture is in the bone around the implant. What can I expect when I see the orthopedic surgeon about this?

It doesn’t happen very often but as you have discovered, an ankle fracture after a total ankle replacement (TAR) is possible. Treatment depends on multiple factors such as your age, your activity level, the location of the fracture, the stability of the implant, and the presence of damage to other areas around the joint.

Thanks to a recent study from Germany, surgeons now have a classification system that will assist them in making decisions about what to do after such a fracture occurs. This classification model is centered around three key factors: 1) cause of the fracture, 2) location of the fracture, and 3) stability of the implant (also known as the prosthesis).

Using their patient base of 503 people, they divided the classification of periprosthetic ankle fractures based on cause into three categories: Type 1 – intraoperative fracture, Type 2 – postoperative traumatic fracture, and Type 3 – postoperative stress fracture. It sounds like you may have a Type 3 fracture.

The classification model divides fracture location into four groups (A, B, C, and D) based on whether the fracture occurred in the medial malleolus, lateral malleolus, tibia, or talus. You didn’t mention the exact location of your fracture but this is something your surgeon will take into consideration when planning follow-up care.

And the last classification variable (implant stability) has two possibilities: stable or unstable. A stable implant is not loose and the fracture does not affect the implant. An unstable implant has signs of loosening with loss of bone around the implant. Each of these three classification parameters (location, type, implant stability) helps determine and guide treatment.

For example, a nondisplaced stress fracture (the bones have not separated at the fracture site) with no sign of implant loosening can be managed nonoperatively (without surgery). If this is the case for you, your lower leg will likely be placed in some type of immobilizer (cast or splint). You may be told to limit how much weight to put on the foot until healing occurs.

If there is fracture displacement, implant shifting or loosening, or malpositioning of the implant, then it is more likely that corrective surgery will be recommended. And each one of these problems calls for a different surgical approach ranging from bone graft to joint fusion. Once your surgeon evaluates you, then a more definite plan of care will be developed. Hopefully, these comments will help prepare you for the meeting with your surgeon and discussion of your specific needs.