Fig. 12.36  Cranialization of the frontal sinus after localized comminuted craniofrontal fracture (CFF). Initial CT (a, b, d) and postoperative result (c, e, f) with perfect reconstruction of

the facial contours (c), resection of the posterior sinus wall and dural reconstruction (f). Residual post-contusional defects in the frontal lobe

Donald and Ettin 1986; Wilson et al. 1988; Ehrenfeld et al. 1996; Sailer et al. 1998; Ernst et al. 2004).

Principle of frontal sinus obliteration

•Total removal of the sinus mucosa

•Careful removal of the inner cortical layer with the diamond burr

•Posterior wall inspection regarding fractures and dural integrity. In fractures without dural injury, the posterior wall should additionally be covered with a membrane or an autogenous graft (pericranium, fascia). In the case of bony defects, the bone fragments can be reintegrated

•Nasofrontal duct occlusion with a cortico-can- cellous bone graft

•Filling the sinus with condensed cancellous bone or with crushed cortico-cancellous bone chips

•Anterior sinus wall replacement, screw fixation or coverage with a bone graft (e.g., tabula externa graft)

Whereas several authors recommend muscle or fat grafts for obliteration, today the use of condensed, autogenous cancellous bone from the iliac crest is favored (Hausamen and Schierle 2000). After thorough homogenization using a bone mill, the bone graft is introduced into the frontal sinus and condensed there.

For stability reasons, the anterior sinus wall has to be reconstructed either with a calvarial bone graft (Prein1998)orbyapplyingtitaniummesh(Kuttenberger and Hardt 2001). If the frontal sinus is obliterated with cancellous bone, a 0.3-mm mesh is recommended for stability reasons and to prevent contour irregulatities due to bone resorption.

12.6  Own Statistics

In 61% of combined comminuted fractures of the anterior and posterior walls, the posterior sinus wall was removed and a cranialization with simultaneous anterior

Fig. 12.37  Comminuted craniofrontal fracture (CFF) with brain injury. (a–c) Impression fracture of the frontal bone with contusional hemorrhage in the left frontal lobe. Fracture of anterior and posterior walls of the frontal sinus and downward displacement

of the orbital roof. (d–f) Postoperative result. Reduction and fixation of the frontal bone fragments with excellent restitution of the contours (d). Resection of the posterior wall of the left frontal sinus (cranialization) and reconstruction of the dura (e, f)

sinus wall reconstruction and obliteration of the nasofrontal duct were carried out. After total removal of the sinus mucosa, the nasofrontal duct was sealed off with a muscle patch from the temporal muscle and a frontal pericranial flap.

In 29% of isolated anterior wall fractures, reconstruction was performed with local bone and miniplates (24%); in 5%, titanium meshes were used.

Obliteration of the frontal sinus with cancellous bone was performed in 7%. In all cases of obliteration, the posterior sinus wall was maintained and the anterior wall reconstructed with a calvarial graft (outer table).

Simultaneous reconstruction of the anterior and posterior wall (without dural injury) was carried out in 3% (Neidhardt 2002).

Techniques for treating frontal sinus fractures (Neidhardt 2002)

Fig. 12.38  Multifragmentary fronto-cranial fracture with CFF. (a–d) Initial CT scan demonstrating comminuted fractures of the nasofrontal complex (a, b), frontal sinus (b, d) and right orbital roof (d). Frontal brain hemorrhage on the right side (c). (e–l) After

reconstruction of the frontal skull base, dural repair and cranialization of the frontal sinus (f, g, l), insertion of a pericranial flap and fixation of the frontal bone fragments with several mini-plates (e, i, j). Excellent restitution of the frontofacial contour (k, l)