Treatment of the postenucleation socket syndrome with a new hydroxyapatite tricalcium phosphate ceramic implant.

Purpose: Surgical correction of the postenucleation socket syndrome (PESS) is challenging. Various biomaterials are used for reconstruction of the anophthalmic orbit, often with unsatisfactory long-term results. Implants have been placed between the periorbital and the orbital floor. The authors describe a new material composed of hydroxyapatite tricalcium phosphate (HA-TCP) in the form of ceramic blocks, to be placed into the orbital fat as a new surgical site.
Methods: Ten patients with PESS underwent surgery to compensate the volume deficit of the anophthalmic orbit. Blocks of HA-TCP were created by fragmentation of a larger piece, tailored as needed, and implanted in the orbital fat. The patients were monitored regularly with clinical and radiologic examinations to evaluate the behavior of the implants.
Results: The volume of the HA-TCP was measured in 5 cases (mean, 2.95 +/- 1.08 ml). A significant reduction of enophthalmos was obtained: mean Hertel exophthalmometry measured 12.7 +/- 2.5 mm preoperatively and 14 +/- 2.4 mm postoperatively (p < 0.05). The average prosthesis volume was significantly reduced in the cases measured: 2.7 ml +/- 0.94 ml preoperatively and 1.8 +/- 0.7 ml postoperatively (p < 0.02). There was a negative correlation between the HA-TCP implant volume and postoperative prosthesis volume (correlation coefficient = -0.925; p < 0.05). According to photographic evaluation, correction of the enophthalmos and of the superior sulcus depression were obtained in 70% and 90% of cases, respectively. Magnetic resonance imaging seems to demonstrate that the blocks become well integrated into the surrounding orbital tissue.
Conclusion: The HA-TCP blocks correct some anomalies of PESS. Placement of the blocks directly into the orbital fat is a promising alternative to the traditional subperiosteal location.