Hemiarthroplasty in young patients has the potential for eliminating bearing wear, but has the disadvantage of cartilage wear.
Low-temperature isotropic (LTI) pyrolytic carbon reportedly reduces cartilage wear in canine hemiarthroplasties. We therefore
initiated a study in humans when it was released for human use. However, we observed failures in some patients. We therefore
document and report the high failure rate observed in a subset of patients treated with an LTI pyrolytic carbon femoral head
for osteonecrosis. We conducted a prospective pilot study of 17 patients treated with a titanium stem and an LTI pyrolytic
carbon femoral head bearing surface for unipolar hemiarthroplasty for either femoral neck fracture (10 patients) or osteonecrosis
(seven patients). One of 10 patients in the fracture group underwent conversion to THA as a result of arthritic progression
compared with six of seven patients with osteonecrosis who underwent conversion to THA as a result of acetabular wear and
severe groin pain. In this small series, patients with osteonecrosis had a higher rate of revision compared with the patients
treated for femoral neck fracture.
Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved the human protocol for this investigation, that all investigations
were conducted in conformity with ethical principles of research, and that informed consent for participation in the study
was obtained.