Failure of Hydroxyapatite Cement Set in Repair of a Cranial Defect: Case Report

Abstract

OBJECTIVE AND IMPORTANCE: Hydroxyapatite cement, a new biomaterial that is being marketed as a method for reconstructing cranial defects, offers many advantages. We document, herein, the complete dissolution and failure of this material to set in a surgically dry field, under optimal conditions, an occurrence that has not been previously reported. CLINICAL PRESENTATION: Hydroxyapatite cement was used for reconstruction of a frontal bone defect secondary to a traumatic depressed cranial fracture in a 9-year-old male patient. At the time of suture removal on postoperative Day 6, we observed serous discharge from the wound, a reappearance of the cranial defect, and brain pulsations visible subcutaneously. INTERVENTION: The patient was returned to the operating room, at which time we learned that the hydroxyapatite cement had migrated out of the defect; small concretions of the cement were scattered throughout the subgaleal space. The concretions of cement in the subgaleal space and the small amount of cement remaining in the defect were removed, and titanium mesh was used. An excellent cosmetic result was achieved. CONCLUSION: Although offering many advantages, hydroxyapatite cement does carry a risk of failure to set, despite optimal technique. Causes for failure to set, as well as possible modifications in the use of material and technique, are discussed.