Reconstruction of an orbital fracture in a mare using a 3D-printed patient-specific implant

To describe surgical repair of an orbital wall fracture communicating with the caudal maxillary sinus using a three dimensional (3D)-printed, patient-specific implant (PSI).

Case report.

A 25-year-old Haflinger mare (370 kg).

The mare presented with severe chemosis and emphysema of the left upper and lower eyelid of 2-weeks duration due to a fracture of the ventral floor and inner wall of the left orbit that communicated with the caudal maxillary sinus. Computed tomographic (CT) data were used to design a PSI replicating the inner surface of the unfractured orbit. The data were converted to an STL file and 3D-printed using polylactic acid (PLA) filament. Surgical access was obtained via a concho-frontal sinus flap combined with sinoscopy. To reconstruct and seal the orbit, the PSI was lined with porcine small intestinal submucosa and secured to the inner orbital wall using two 3.0 mm titanium locking screws and synthetic, non-absorbable transosseous fiber loops.

The emphysema resolved postoperatively, and ocular function was unrestricted by the implant. Infection developed subcutaneously adjacent to the transosseous suture fixation at the maxillary bone but resolved with conservative management. Follow-up CT at 11 weeks and owner reports after 18 months confirmed a favorable cosmetic and functional outcome, with only minimal residual ptosis of the left upper eyelid.

Application of a PSI axially to the left orbit successfully reconstructed the orbital wall and resolved the communication with the caudal maxillary sinus.

Patient-specific implants represent a novel surgical option for the repair of complex orbital wall fractures in horses.