Short Notes in Plastic Surgery

June 3, 2013

34. Fractures of the Nasal Skeleton

Filed under: Chapter 34 — ravinthatte @ 3:50 am

34. Fractures of the Nasal Skeleton

1.   The two nasal bones, which project forward from the face, are by far the weakest part of the facial skeleton and are fractured frequently because of this projection. They however constitute only a small part of what is collectively called the nasal skeleton. The two nasal bones articulate with the frontal bone above and maxilla laterally (nasal process of the maxilla) and are joined in the midline (Fig. 1 and 4). They therefore form a bony triangle which only in its lower one fourth, sits on the cartilaginous septum which below that level divides the nasal cavity in to two parts (Fig. 2 and 3). Above this level the partitioning is effected by the perpendicular plate of the ethmoid up to the posterior nasal coana which leads in to the nasopharynx.

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A fracture of the nasal bone within itself is a rarity because of its small size (Fig. 5) and fractures occur more frequently when a blow to the nose fractures their attachments to the frontal and the maxillary bones. Here too such a disruption of a single nasal bone is comparatively uncommon (Fig. 6). The more frequent occurrence being the tent fracturing on all four sides (Fig. 7). This results in a tilt to one side or the other. This description does not include injuries caused by shattering forces where the nasal bones together with its surrounding skeleton may be smashed in to several small parts.

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2.   The septal cartilage (light pink) which constitutes the lower two thirds of the nasal profile sits on the palatine process of the maxilla (red). It articulates with the Vomer behind and inferiorly (golden yellow) and with the ethmoid bone (pale yellow) posteriorly and superiorly. The ethmoids are anterior to the sphenoid sinus (SPH). The Cribiform plate (dotted blue line) from which the olfactory nerve exits is above this area.

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A blow to the nose can fracture the septum, in addition to the nasal bones. This can happen sometimes without any fracture of the nasal bones. If the septal mucosa holds, a haematoma may form. If the septal mucosa gives way it leads to obvious epistaxis or may cause a trickle into the naso-pharynx. A fracture of the nasal bones tears its mucosa and also leads to epistaxis. When the septum fractures, the two parts might over ride each other. This might occur at one or two points and is usually called ‘buckling’ (Fig. 9). This is one of the commonest causes of a depressed nose in the middle two-thirds and when combined with a displaced fracture of the nose gives it a crooked appearance leading to the commonly used term, ‘a crooked nose’ (Fig. 10). Occasionally the septum dislocates from its Vomerine attachment with a fracture, leading to a tilted tent effect in the middle two thirds of the nose. The whole of the nasal tent may then tilt if the bones also are fractured (Fig. 11).

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Figures 12 to 17: Frontal and slightly to the side impact leading to loss of frontal profile

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3.   Not infrequently a severe blow to the nose from the front will not only fracture the nasal bones and the septum but the bones will be driven backwards, telescoping into the ethmoid bone with its air cells and the ethmoid will collapse and / or will be driven backwards altogether towards the floor of the anterior-cranial fossa up to the cribriform plate which might give way. When the injury is compound and the meninges are torn, a CSF rhinorrhoea might follow. Rarely brain matter may seep through the zone of injury and appear in the nose (Fig. 26, 27).

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4.   The nasal bones in their vicinity are related to the lacrimal bone, the lamina papyraecea a little posteriorly and the thin inferior orbital wall laterally and inferiorly (inferior orbital fissure). All these might be fractured when the trauma is severe. Communited fractures surrounding the medial wall of the orbit will affect the medial canthal ligament. The ligament is rarely avulsed from the bone but the bone itself having moved laterally carries the ligament with it and causes telecanthus. In poorly treated and/or malunited fractures around this area obstruction to the naso-lachrymal duct is not unknown and might need recanalisation and / or a dacro-cysto rhinostomy. Impacted fractures of the bone overlying the maxillary or frontal sinuses may be present and will require treatment such as disimpaction and fixation of fractured fragments (Fig. 28, 29).

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5.   The nasal skeleton is exceptional in the sense that it is surrounded by sinuses, maxillary sinuses on either side, the frontal sinuses superio-laterally and the ethmoid sinus in three parts behind which are related further posteriorly to the sphenoid sinus below the sella-turcica (Turcica=Turkish saddle). All of them open on the lateral wall of the nose on which are three conchae, superior, middle and inferior of which the inferior is a bone by itself, the other two being parts of the maxilla (Fig. 30, 31). All these structures might be in one way or the other involved in fractures around the nasal skeleton.

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6.   There are practical problems in the treatment of the fractured nose or nasal skeleton that exist certainly in countries such as India.

a.   Many of these fractures are seen in the casualty departments of hospitals and the system of referral is lackadaisical in that general, ENT, plastic and even orthopedic surgeons opine and then treat these patients. Maxillofacial surgery is a recent addition to this group but is not necessarily represented in a general hospital. A vast majority present with deformities that are not life threatening and are soon hidden by hematoma or swelling, an examination with a speculum is either difficult or not done at all and therefore the septal component of the injury remains undiagnosed. Epistaxis of any severity is treated with packs and, should there be a nasopharyngeal leak of blood (often increased by the packing of the anterior half of the nose), the patient is admitted, observed and then discharged when the bleeding subsides. Routine x-rays diagnose the fracture but not its full nature and with swelling all around and a pack inside the nose a CT-scan gets postponed, certainly in public hospitals where preference is given to more serious cranial injuries. In the event, leaving aside the nature of the nasal fractures, a proper and crucial diagnosis of the septal injury does not get made. This is particularly damaging in the region of the naso-ethmoid which might have telescoped backwards. If the cribriform plate and the meninges are violated the CSF leak may remain undiagnosed when epistaxis is present till the bleeding subsides and the clear nature of the discharge alerts the clinician.

b.   Having said that, notwithstanding the introduction of the sophisticated instrumentation including small caliber drills and various plating systems, the nasal skeletal injuries seem to be strangely excluded from these techniques. The nasal bones are too small and friable to fix and an open access to that area involves incisions and therefore scars which there is a natural tendency to avoid. Scalping flaps, now very common for craniofacial surgery, are rarely undertaken unless the fractures are complicated and involve the orbit. The septum is easily manipulated through the nostril and can be straightened and corrected but it is difficult to fix except indirectly by way of packing the nostrils and an external plaster. A thick wire or a thin nail can be passed transcutaneously just above the pyriform fossa through the septum to hold it in the corrected elevated position but this is at best a blind procedure.

c.   Even with due diligence and proper CT-scans, when the nasal bones are reduced to their original position and then plastered with an extension on the forehead, septal correction in the presence of hematoma and swelling is extremely difficult and rarely done primarily.

d.   The treatment of “boxed in” fractures of the naso-ethmoid complex continues to remain unsatisfactory. It is well nigh impossible to re-expand the ethmoid complex. The nasal bones which have been boxed in may be shattered into small parts and even when they are in one piece when extracted from their ‘boxed in’ position and reduced into their normal location their appearance remains wanting as compared to their original contour.

e.   The repositioning of the piece of maxillary bone to which the canthal ligament is attached (with wiring) might seem to anatomically reduce the fractures into their original position but here too the fixation is difficult and some telecanthus might remain.

7.   This description is given to argue that many of the post-traumatic deformities in this area come to plastic surgeons as a secondary deformity. Be that as may the following steps need to be taken in the primary treatment.

a.   The traditional treatment of CSF rhinorrhea was to wait for it to subside naturally and intervene only if it persisted for more than two or three weeks. The criteria were vague and continue to be so. Craniofacial surgery is now undertaken with ease in several centres and in cases where the fractures of the nasal skeleton are compound and therefore there is fear of infection, a more aggressive approach to ensure closure of the nasal cavity from the intra-cranial space is certainly justified. A patch of fascia might be used for this purpose (within the cranium). The temporalis fascia suggests itself as a useful candidate for this closure in view of it lying in the vicinity of the bi-coronal incision. The development of the Galeal flap in the course of craniofacial surgery can also now be used and has the added advantage of being a live tissue. In the more modern transnasal procedure, the cribriform plate is approached by a long naso-endoscope through the ethmoidal cells, the site of the leak is located and is then repaired by a perichondrial flap from high up in the septum, or by a piece of free cartilage also from the septum or by a patch of fascia acquired from some other part of the body. This area is then packed very closely and in order to support this high pack another pack is introduced in the lower half of the nose. In all these procedures a head high position, a reduction of intra-cranial pressure by diuretics or mannitol is usually employed to take of pressure from the part which is repaired.

b.   When the nasal bones are impacted under the frontal bone and / or are driven behind into the ethmoidal area their disimpaction is difficult by the standard use of the Walsham’s forceps (please see para c below). Occasionally a sharp elevator will have to be introduced through an incision at the root of the nose to go behind the fractured impacted pieces and, since many of these injuries are compound, no fresh incision requires to be taken. As stated earlier, this disimpaction more often than not is unsatisfactory, partly because during the force of impaction the nasal bone is fragmented and does not come out in one piece. A surface plaster with a forehead extension and a nasal pack is usually employed to keep the reduced bone in its place. If the nasal bones are in one piece, fixation to the frontal bone with a wire is attempted.

c.   In standard fractures of the nasal skeleton a Walsham’s forceps is used to reduce nasal bones. In the process brisk bleeding may be caused because the mucosa may tear further during reduction. The septum’s dislocation / fractures / displacement are reduced by the Asche’s forceps and are then allowed to stay in their repaired place again by nasal packs and a surface plaster. While reducing the septum it is advisable to do a proper inspection of its surface and if necessary repair any tear of the mucosa if it is extensive. During the reduction of the septal fracture bleeding can be brisk because the procedure violates the mucosa and pent up hematoma might drain out as the forceps inevitably causes some additional injury. Rarely a visible, spurter might need to be cauterized (Fig. 32,33,34).

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The compiler of these notes thanks Uday Bhat (plastic surgeon), Divya Prabhat (ENT surgeon), both from Mumbai and Shailesh Nisal (plastic surgeon) from Nagpur for illustrations. Some of the diagrams have been borrowed from the latest edition of Grey’s Anatomy, drawn with the help of a tracing paper and then photoshopped for various colours, arrows etc.

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