Early Hypoglobus in Orbital Floor Reconstruction With Resorbable Implants

Among the variety of materials developed for facial bone surgery, resorbable implants are widely used in orbital wall reconstruction. There are many advantages in selecting resorbable implants, such as minimal foreign body reaction and adjustability within the damaged orbital floor. Resorbable implants are supposed to remain in place over 1 to 2 years to hold the structure of immature healing tissue surrounding the bony defects. However, some patients who have undergone orbital wall reconstruction surgery with resorbable implants suffer from early hypoglobus.

This retrospective study was performed from January 2014 to August 2019 and follows 39 patients with unilateral pure orbital floor fractures. All orbital floor reconstruction was performed using resorbable implants via the transconjunctival approach. Exophthalmometer measurements and CT scans showing the degree of implant sagging were used to provide an index of hypoglobus.

Most patients showed hypoglobus over 3 to 4 months follow-up. The size of bony defect in the orbital floor showed positive correlation with follow-up exophthalmometer measurement and degree of implant sagging.

Orbital floor reconstructed with resorbable implant tends to lose load-bearing strength gradually, especially in large bony defects. Therefore, surgeons should be cautious about using resorbable implants for the maintenance of reconstructed orbital floor, especially in large bony defects.