Hydroxyapatite cement resistant to fragmentation following full cerebrospinal fluid bathing.

Prolonged cerebrospinal fluid bathing of cranioplasty cement frequently results in breakdown of the cement implants. A 5-year-old boy with a history of severe head trauma at 2 weeks of age presented with marked protrusion of the entire superior temporal bone and inferior parietal bone. The defect was elevated by more than 1 cm and was associated with a 4.5 x 3-cm skull defect located above and behind the right ear. There also was pulsatile tissue at the depths of the defect. A computed tomographic scan taken of the head revealed an expanding skull fracture from a dural defect with underlying brain herniation. The cranial lesion was repaired with OsteoVation hydroxyapatite cement. Within 8 weeks, the fluid encased the cranioplasty site. This resolved following implantation of a shunting device. At 2 and 12 months after the repair, the implant was still palpably solid without breakdown and did not fragment despite the prolonged bathing in cerebrospinal fluid.