Journal of Long-Term Effects of Medical Implants

Nontraumatic Fracture of a Custom-Made Wagner Cone Prosthesis Hip Stem: A Case Report

ABSTRACT

Fractures of modern cementless stems are almost extinct. However, extra small stems used for cases of developmental dysplasia of the hip (DDH) are still at risk for this complication.
We review the fracture of a small size 11, custom-made Wagner cone prosthesis in a 70 year old female patient. The patient had a body-mass index (BMI) of 22.2, 7 yrs after undergoing a total hip arthroplasty. The procedure was undertaken to correct extreme high-riding congenital hip dysplasia. She presented with sudden pain due to a non-traumatic fracture of the stem, just below the proximal third region. At revision, it was apparent that the stem had a concrete distal fixation, whereas the proximal part was loose and probably failed due to cantilever bending fatigue, although the patient had small stature and a low BMI. We trephined out the distal portion, and the patient was successfully revised with a cemented DDH Co-Cr stem.
It is our belief that care should be taken when choosing extra small, cementless implants with distal fixation. Cemented prostheses may offer a safe alternative in such cases.