Posterior table fractures of the frontal sinus: I. An experimental study

Experiments using cats were performed to examine the natural history of posterior table fractures of the frontal sinus and the methods available for treatment. Elevation of depressed fractures and obliteration by either fat or osteoneogenesis and fibrosis were the modalities of treatment used. Comparisons were made with untreated controls. Fascia reinforcement of the dura and plugging of the nasofrontal duct were variables. The nasofrontal duct is critical in the natural history of these injuries. All fractures of the posterior table heal if drainage into the nose is maintained. Fractures which are elevated heal by bony union with associated mucosal and dural healing. Loose fragments of the posterior table heal if left in place. Mucoceles form if the nasofrontal duct is obstructed, if mucosa is inadequately removed during obliteration and, in some instances, where islands of mucosa are isolated by mucosal laceration. Viable adipose tissue in the sinus prevents significant ingrowth of mucosa from the nasofrontal duct. Growth of mucosa into fracture lines was not a problem. Both adipose transplants and intrasinus fascia reinforcement appeared to contribute to well defined posterior table healing.