The risk of nasal osteotomies after ethmoid sinus surgery

To assess whether there is an increased risk of osteotomies causing fractures that extend into the orbit or cranial base in patients who undergo ethmoid sinus surgery.

Anatomic investigation in a cadaver model.

Twenty-eight medial and lateral osteotomies were performed in 14 fresh-frozen cadaver heads after bilateral sphenoethmoidectomies (endoscopic technique, n = 26; external technique, n = 2). Anatomic examination performed by inspection after removal of dorsal nasal skin followed by rigid endoscopic intranasal examination.

Complete osteotomies were obtained in every case. There were no major comminutions along the osteotomies, but there was a 25% rate of minor comminutions. In no case did fractures extend into either the orbit or the base of the skull. In every case, the path of the osteotome was separated from the ethmoid surgical cavity by a relatively thick buttress of bone composed of the anterior lacrimal crest and the ascending process of the maxilla. The enlarged maxillary ostia created by the sinus surgery was not altered by the osteotomies or by dorsal narrowing.

Nasal osteotomies can be performed with minimal risk of comminution or uncontrolled extension of the fracture lines following extensive ethmoid and sphenoid sinus surgery. These findings may not apply in patients with preexisting injuries or when osteotomies do not preserve the triangular nasal buttress.