ASSESSING THE EFFECT OF SINUS SURGERY ON ORBITAL FRACTURES: IMPLICATIONS FOR PATIENTS WITH RHINOSINUSITIS

Functional endoscopic sinus surgery (FESS), commonly performed to alleviate symptoms of chronic rhinosinusitis, may weaken the thin orbital walls which are susceptible to fracture in facial trauma. This study aims to assess how FESS affects orbital fracture risk. Ten fresh-frozen cadaveric heads underwent FESS on one side. The contralateral side served as intra-specimen control. Orbital trauma was induced using a guided weight-drop technique. Both orbits were tested using sequentially higher drops until orbital fractures were detected on computed tomography scans. Bone mineral density (BMD) was analyzed. All heads presented with a preferential medial wall fracture on the surgical side and orbital floor fracture on the non-surgical side (p \u3c 0.01). Reduction in the energy required to induce a fracture in the medial orbital wall post-surgery, and the correlation between BMD and impact energy, was not significant (p \u3e 0.05). Results provide improved informed consent for patients with chronic rhinosinusitis

Does endoscopic sinus surgery alter the biomechanics of the orbit?

© 2020 The Author(s). Objective: The purpose of this study is to determine if removal of ethmoid cell septations as commonly performed in endoscopic sinus surgery leads to a change in orbital wall fracture patterns and the force required to create them. Methods: Six fresh-frozen cadaveric heads were acquired and underwent endoscopic uncinectomy, maxillary antrostomy, and anterior and posterior ethmoidectomy on one, randomized, side. The contralateral sinuses were used as intra-specimen control. Hyaluronic acid gel globe injections were performed to simulate normal intra-ocular pressure. Post-op CT scans confirmed no orbital fractures or violation of the lamina papyracea prior to trauma testing. Orbital trauma was induced using a guided weight-drop technique. Both orbits were tested in random order, and sequentially higher drops were performed until both the test and control side demonstrated an orbital fracture on CT scan. Results: In all six heads, the post-sinus surgery side incurred a medial orbital wall fracture, and no orbital floor fractures were identified. On the other hand, on the control side, all six heads incurred orbital floor fractures at drop heights equal to, or higher than, the surgical side. Fisher\u27s exact test demonstrated a significant difference in fracture pattern (p \u3c 0.001). Conclusions: To our knowledge, this is the first demonstration that the structures removed during sinus surgery may act as a buttress for the medial orbital wall. The anatomic changes of sinus surgery may alter the biomechanics of the orbit and affect the pattern of subsequent traumatic blowout fractures