Abstract
Purpose :
To evaluate the efficacy of the Medpor nonporous barrier sheet as a substitute for supraFOIL in orbital fracture repairs.
Methods :
A prospective, case series using the Stryker 0.4mm thick medpor nonporous barrier sheet in patients presenting with orbital fractures. Patient age, type of fracture, etiology of injury, presence of pre-operative restriction and diplopia, and post-op diplopia and/or enophthalmos were recorded. Patients were followed or will be followed for 6 months. Scanning electron microscopy was used to compare the thickness, smoothness, and porosity of the Medpor nonporous barrier and SupraFOIL implants. Beam deflection testing was performed to compare the biomechanical properties of each implant.
Results :
47 patients underwent repair of orbital fractures with the Medpor nonporous barrier sheet. Average age was 43.3 years (range 18-84). 27 of 47 patients (57.4%) were males and 20 (42.6%) were females. The most common cause of injuries were: Assault (38.3%), MVA (14.9%), falls (25.5%), and sports-related (10.5%). 20 of 47 patients (42.6%) had isolated orbital floor and 2 patients (4.3%) had isolated medial wall fractures. 15 patients (31.9%) had combined floor and medial wall fractures involving the inferomedial orbital strut. 28 patients (59.6%) had pre-operative diplopia. Timing of surgery was between 3 and 55 days, with the median of 11.5 days. 5 of 47 patients (10.6%) has residual diplopia at their 1 week post operative visit, each had resolved at 2 months post op. Electron microscopy showed that the 0.4mm Medpor nonporous barrier implant was thinner (0.33mm) than reported and thinner than 0.4mm SupraFOIL (0.38mm). SEM also showed that the surface of the Medpor nonporous barrier was smooth and nonporous. Beam deflection testing showed that for small forces (< 100 mN) the two materials behaved nearly identically, but at higher forces the nonporous Medpor implant was weaker.
Conclusions :
The use of Medpor nonporous barrier sheet implant for orbital fracture repair is a safe and effective alternative. There were no complications and no residual diplopia or restriction. The “0.4mm” Medpor nonporous barrier was thinner (0.33mm) than SupraFOIL implant (0.38mm). The Medpor nonporous barrier was also weaker when compared to SupraFOIL at higher forces >100 mN. This may require thicker implants (~0.5 -0.6 mm) for combined orbital floor and medial wall fractures where the orbital strut is involved.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.