Effective correction of frontal cranial deformities using biodegradable fixation on the inner surface of the cranial bones during infancy.

PURPOSE: Fixation of cranial bones in pediatric craniofacial surgery with biodegradable materials has developed into an accepted method. However, placing the fixation material on the outer surface of the cranial bone at the frontal cranium in infants can result in suboptimal cosmetic outcomes, as the plates and screws can be palpable. The placement of resorbable fixation devices on the inner surface of the skull would allow for less obvious fixation beneath the skin with a potentially superior cosmetic result. The authors report the use of such resorbable fixation devices on the inner or endocranial aspect of the cranium which appears to be novel. MATERIALS AND METHODS: Ten patients with the mean age of 14 months (range 7-35 months) were treated with cranial remodeling using poly(lactide-co-glycolide) (PLGA) biodegradable fixation on the inner surface of the cranial bones. Five patients had trigonocephaly, four plagiocephaly, and one brachycephaly. All patients had 3D computed tomography (CT) and clinical photographs done preoperatively and postoperatively at follow-up. The outcome was judged at follow-up by clinical evaluation, photographs, 3D CT, and interview of the parents. The mean follow-up time was 3.5 years (range 0.5-6 years). RESULTS: The primary recovery was uneventful in all cases. No wound infection occurred, but one patient had a minor skin necrosis which required a single revision operation to correct. The cosmetic outcome was scored as excellent, good, fair, or poor. There was no case with delayed union. Seven out of ten cases were judged as excellent and three as good, none as fair or poor. CONCLUSIONS: The use of resorbable PLGA fixation devices on the inner aspect of the skull appears to provide a satisfactory cosmetic result in this small preliminary group of pediatric patients. Further long-term study of these materials in this specific location in a larger patient group is needed.

Bone tissue engineering: treatment of cranial bone defects in rabbits using self-reinforced poly-L,D-lactide 96/4 sheets.

This study is one of a series in which the authors evaluate various absorbable sheets to guide bone regeneration in cranial bone defects. The aim was to evaluate the use of self-reinforced poly-L,D-lactide 96/4 (SR-PLA96) sheets for cranial bone tissue engineering in experimental defects in rabbits. Square defects of 10 x 10 mm were created in the right parietal bone. SR-PLA96 implants (15 x 15 mm) were used to cover these defects in 12 New Zealand White rabbits. Similar defects were created in the left parietal bone, but no sheets were used (controls). The rabbits were killed after 6, 24, or 48 weeks. Histology and histomorphometry were used to evaluate healing of the defects. Defects covered with SR-PLA96 sheets showed more abundant bone formation than control (non-covered) defects. At 6 weeks, the defects were occupied mainly by fibrous tissue. At 24 weeks, healing with bone formation was more obvious in the covered defects. At 48 weeks, bone completely bridged defects covered with SR-PLA96 sheets, and incomplete bridging was seen in non-covered control defects. Hence, bone tissue engineering in experimental cranial bone defects in rabbits can be achieved using SR-PLA96 sheets to guide bone regeneration.