Synthetic hydroxyapatite orbital implants: a clinical and MRI evaluation

Purpose Coralline hydroxyapatite orbital implants have been used since the 1980s. More recently, synthetic hydroxyapatite orbital implants have been u sed, in both primary and secondary orbital implantation surgery. The implan t may be drilled and pegged, if required, after adequate vascularisation of the implant has occurred. In this study we evaluated the clinical results and vascularisation of synthetic hydroxyapatite orbital implants. Methods Twelve consecutive patients who had synthetic hydroxyapaptite orbit al implants were evaluated clinically and 8 of these patients had orbital m agnetic resonance imaging (MRI) scans with intravenous gadolinium performed at least 9 months postoperatively to assess vascularisation of the implant . Six patients had primary orbital implants at the time of enucleation and 6 patients had secondary implants. Results No significant complications occurred following insertion of the sy nthetic hydroxyapatite orbital implants. All patients reported cosmetic sat isfaction with the results of surgery. MRI scans revealed inhomogeneous enh ancement in 3 of the 4 patients receiving primary implants. All patients wi th secondary implants and 1 patient who had a primary implant had moderate to large areas of poor enhancement in the implant. Conclusion Synthetic hydroxyapatite implants gave good clinical results but variable vascularisation occurs, especially with secondary implants.