Pediatric cranial vault defects: early experience with beta-tricalcium phosphate bone graft substitute

Pediatric calvarial defects may result from numerous causes. Availability of bone is often limited because of the child's age, and bone substitutes may be needed to reconstruct the defects. A bone substitute composed of ultraporous beta-tricalcium phosphate (Orthovita, Malvern, PA) is an osteoconductive product successfully used in orthopedic surgery. However, its application in cranial vault reconstruction is largely unstudied. The purpose of this investigation was to determine the healing rate of bone defects with the use of this product.A retrospective review was performed of patients in whom beta-tricalcium phosphate was used. Patient population consisted of 23 patients. Mean surgical age was 35 months. Reconstructions consisted of 20 craniosynostosis corrections and 3 posttraumatic repairs. The average defect size was 37 cm (range, 4.6-210 cm). Average follow-up was 12.7 months.At 2 months, 19 (79%) of 23 patients achieved healing of their defect, defined as the absence of persistent bone gaps. Persistent areas of bone weakness occurred in 3 patients at 4 months and 2 patients at 6 months. By 9 months, only 1 patient had not healed. This patient had the largest original defect of 210 cm. Defects taking longer than 2 months to heal measured 83 cm, whereas healed defects were 32 cm. No patients required treatment for graft-related problems such as infection or exposure.Early experience with beta-tricalcium phosphate bone substitute shows good healing of pediatric calvarial vault defects by 2 months, with no graft-associated complications. It seems most effective in the repair of smaller defects less than 40 cm.