When Revising the Stem Is the Only Option
According to Anthony Hedley, MD, FRCS, when dealing with a type B periprosthetic femur fracture, the treatment option the orthopaedic surgeon selects will depend on:
- Status of fixation of femoral component
- Morphology of the fracture
- Quality of the proximal bone
Dr. Hedley shared his advice on revising the stem after a periprosthetic femur fracture with the attendees at the recent ICJR West meeting. Fracture types are based on the Vancouver Classification of Postoperative Periprosthetic Femur Fractures.
Type B1 Fracture
A type B1 fracture occurs around or just below the stem; the stem is well fixed.
This is the exception to the rule that the status of fixation dictates the treatment option. The stem needs to be removed, Dr. Hedley says: The struts or struts and plating of the original fracture have failed, and once they have been removed, the fracture site is not very healthy. It’s time to move on to other options, namely, conversion to a long stem.
Type B2 Fracture
This fracture is found around or below the stem. The stem is loose and the femoral component needs to be revised.
Options for treating a type B2 fracture include:
- Extensively coated stem with diaphyseal fixation
- Fluted modular non-cemented stem
Dr. Hedley prefers fluted conical stems over extensively coated stems. The fluted modular non-cemented stem is good choice, he said, not only because it affords rotational stability, but also because this modality offers the ability to “fine tune” the head and the body of the stem.
Dr. Hedley offered these tips for managing type B2 fractures:
- The fracture line can be used as the “extended osteotomy. Dr. Hedley tries to avoid osteotomies whenever possible, but if one must be done, especially to remove cement, Dr. Hedley urges surgeons to reassemble the femur before reaming for the implant.
- Keep soft tissue dissection to a minimum; don’t devitalize the femur
- Good proximal support is necessary when using a fluted stem to prevent fatigue fracture of implant. This may not be as much of a problem anymore – issues with earlier models have been resolved through modifications to the stem.
- Strut allografts may be used for better initial stability to the implant.
Type B3 Fracture
A type B3 fracture occurs around or right below the stem. The stem is loose, and there is poor proximal bone stock. This fracture requires revision of the femoral component.
Dr. Hedley has these tips for treating type B3 fractures:
- Restoration of bone stock is a priority in younger patients, although Dr. Hedley does not often use bone grafts. He believes the bone will generally restore itself, especially in a recent primary total knee arthroplasty.
- Allograft prosthesis composite is a good treatment option.
- Proximal femoral replacement (either metal or bone) can be used in older or low-demand patients
- Regardless of quality, the proximal part of femur should be retained and wrapped around prosthesis. Don’t throw away bone: Denuding the proximal femur and discarding bone fragments and the muscle attachments may lead to instability and dislocation.
- Constrained acetabular liner may be used to prevent instability due to soft tissue deficiency.
Watch Dr. Hedley’s presentation by clicking the button below.