Doctors at Mayo Clinic report 21 cases of intraoperative acetabular fracture in total hip replacements (THRs). There were a total of 7,121 patients in the study. It is rare that this type of problem occurs during the procedure. The acetabulum is the socket portion of the hip that is replaced.
In this study, only uncemented cups were fractured. There were three general cup types used. The groups were based on shape and diameter. These included elliptical monoblock, elliptical modular, and hemispherical modular.
The two cup designs that fractured most often were the Implex elliptical monoblock and the Peripheral Self-Locking (PSL) elliptical modular. Most of the cups were stable and further treatment wasn’t needed. The surgeon placed some extra bone graft along or into the fracture line. X-rays showed healing occurred with bone in-fill.
The authors give surgeons specific instructions about using elliptical monoblock cups since most of the fractures occurred with this design. They suggest the stress of putting this type of cup into the hip can lead to fracture. The surgeon must be prepared for this event even though it doesn’t happen very often.