Background: Despite the growing popularity of calcium-based bone cements as a cranioplasty material, the long-term success and complication rates of these materials remain largely controversial. The authors reviewed their extended experience with Norian, a carbonated calcium phosphate bone cement, for cranioplasty.
Methods: A retrospective chart review of all patients who underwent cranioplasty using Norian over the past 9 years was conducted. Patients with less than 1 year of follow-up were excluded.
Results: Forty-six patients were studied. Follow-up averaged 43.9 months (range, 12.1 to 109.8 months). The overall complication rate was 26 percent, and included infection (n = 9), seroma (n = 1), or a chronically draining sinus (n = 2). Average time to onset of a complication was 20.2 months (range, 2.3 to 89.2 months). Two of nine infections resolved with oral antibiotics; the remaining complications required surgical intervention for definitive treatment. Factors associated with a statistically increased risk of complications were amounts of Norian used (p < 0.01) and onlay application with a high probability for bacterial contamination (p = 0.001), whereas reconstruction of full-thickness cranial defects larger than 25 cm trended toward worse outcomes (p > 0.05).
Conclusions: Norian is well suited for cranioplasty when used in moderate amounts for onlay applications, as evidenced by acceptable complication rates and contouring ability in this setting. Its use in large amounts as an onlay, inlay full-thickness cranial reconstruction of large defects or areas with potential bacterial contamination should be avoided. Complications or construct failure may occur months or even years after implantation, even under ideal circumstances.