Feasibility of Single Folded Unsintered Hydroxyapatite Particles/Poly-L-Lactide Composite Sheet in Combined Orbital Floor and Medial Wall Fracture Reconstruction

Abstract

Combined orbital floor and medial wall defect fractures can be challenging to repair. The aim of this retrospective clinical study was to evaluate the feasibility of single folded uncalcined and unsintered hydroxyapatite (u-HA) particles and poly-L-lactide (PLLA; u-HA/PLLA) composite sheets with a tack fixation technique in computer-assisted combined orbital floor and medial wall complicated fracture reconstruction. This study included five patients (mean age, 27.2 years) with relatively large complex orbital floor and medial wall defects (three type III defects and two type IV defects). A single folded u-HA/PLLA sheet was fabricated and prepared with an average optimal orbital floor to mesial walls angle (OHMW-angle) of 130.84° ± 5.42; this was followed by adaption and stable fixation with tacks to the inferior orbital rim using computer-assisted and intraoperative navigation-assisted orbital reconstructive surgery. The clinical and radiological data were analyzed, and ophthalmologists diagnosed functional eye complications with a mean follow-up period of 9.1 months (range, 6 to 18 months). Although the postoperative computed tomography (CT) study revealed accurate three-dimensional (3D) orbital wall reconstruction, a slight OHMW-angle increase, to 133.68°± 4.28, between the orbital floor and medial reconstructed walls was observed 1 month postoperatively compared with immediately postoperatively (p < .05), but no other angle changes were observed in the postoperative follow-up study (p > .05). There was full recovery of ophthalmological function and active eyeball mobility without enophthalmos or diplopia. Overall, computer-assisted single folded u-HA/PLLA sheets with a tack fixation technique provide stable and satisfactory ophthalmologic functional results for combined orbital floor and medial wall fracture reconstruction with no intraoperative or postoperative complications. Furthermore, this u-HA/PLLA composite sheet could be an optimal next-generation bioactive osteoconductive implant material for the reconstruction of relatively large orbital wall defects, which could be applied using computer-assisted surgery.