------------------------------------------------------------------------------- TITLE: NASOETHMOID COMPLEX FRACTURES SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: April 26, 1989 RESIDENT PHYSICIAN: Terry McMillan MD FACULTY: Chester Strunk MD DATABASE ADMINISTRATOR: Melinda McCracken, M.S. ------------------------------------------------------------------------------- "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. ANATOMY A.nasoethmoid complex 1. the architectural foundation of the complex consists of a strong triangular shaped frame. a. apex formed by frontal bone and nasal process of frontal bone b. the sides are formed by the frontal processes of the maxilla c. the premaxilla forms the base of the triangle 2. the remainder of the skeletal framework of the complex is fragile 3. behind the triangular frame lies the interorbital space a. the medial orbital walls b. ethmoid air cells c. nasal septum d. cribriform plate e.superior and middle turbinates 4. the nasal bones unite with each other and the frontal bone in front of the triangular frame-work B. medial orbital wall 1. bony anatomy a. the orbital cavity is a four sided pyramid with the base facing anteriorly b. the medial walls are parallel to the sagittal plane c. the lateral walls diverge at an angle of 45 degrees from the medial walls d. the apex of the pyramid is at the region of the optic foramen e. the orbital rims are extremely strong f. in contrast, the medial and inferior walls are very fragile g. medial bony walls consists of 1. frontal bone 2. frontal process of maxilla 3. lacrimal bone 4. ethmoid 5. sphenoid h. the lacrimal fossa lies between the anterior and posterior lacrimal crests i. the medial wall of the orbit is in immediate relation to the ethmoid, sphenoid, and frontal sinuses 2. soft tissues a. the medial canthus 1. the medial canthal area is a complex structure involving the medial canthal tendon and the lacrimal drainage system 2. orbicularis fibers divide medially into deep and superficial heads with the superficial being much larger 3. the superficial heads fuse medially to form the medial canthal tendon which attaches to the anterior lacrimal crest 4. the deep heads attach to the posterior crest 5. the lacrimal sac is sandwiched between the two 6. in this way the eyelids are firmly fixed to the bone medially b. the lacrimal drainage apparatus 1. the upper and lower puncta lead to the upper and lower canaliculi which are 2 mm in diameter and 10 to 11 mm in length 2. the upper and lower canaliculi unite to form the common canaliculus, only 2-3mm in length which in turn empties into the lacrimal sac 3. the sac is invested by fascia and the anterior and posterior portions of the medial canthal tendon 4. the nasolacrimal duct runs vertically 20 mm through the maxilla into the inferior meatus c. the lacrimal pump 1. with each blink, the orbicularis fibers cause shortening of the canaliculi and compression of the lacrimal sac 2. tears are thus forced through the nasolacrimal duct 3. with muscular relaxation, expansion of the lacrimal apparatus to its original size induces a negative pressure within the system 4. this negative pressure siphons tears from the medial fornices into the collecting system d. trochlea 1. a "u" shaped piece of fibrocartilage transmits the tendon of the superior oblique 2. attached to the frontal bone one cm posterior to the orbital margin 3. the superior oblique depresses the eye when its in the neutral or adducted position 4. detached trochlea results in diplolpia on downward gaze 5. the patient may tilt his head toward the opposite shoulder to compensate II. The Nature of the Injury A. the essential basis of this injury is fracture and displacement of the skeletal triangular framework, in particular the frontal processes of the maxilla B. force of sufficient magnitude to fracture the triangular framework will result in severe comminution and displacement of the other bony structures in addition to injury to the soft tissues of the medial canthal region C. the transmitted forces result in the nasal structures being driven backwards between the orbits D. impaction from nasal and ethmoid structures results in crumbling of the medial orbital walls and medial displacement E. traumatic telecanthus may result--the medial canthal tendon is no longer fixed F. this injury is found most often in association with other facial fractures III. Clinical Features A. broad, flattened, depressed nasal root often with an accompanying laceration B. periorbital ecchymosis and considerable swelling and difficulty of inspection C. traumatic telecanthus 1. rounded medial canthus with prominent epicanthal folds 2. loss of caruncle and shortened palpebral fissure 3. almond shaped palpebral fissure 4. accentuated nasojugal fold due to posterior canthal displacement 5. normal intercanthal distance is roughly equal to the interpalpebral distance 6. with edema obscuring the medial palpebral angle, this width may be difficult to ascertain 7. alternatively, one can measure the interpupillary distance which is normally twice the intercanthal distance 8. normal values are 60 to 70 and 30 to 35 mm, respectively 9. bowstring test will demonstrate laxity of the upper, lower, or both eyelids D. epiphora 1. epiphora is not a reliable acute sign of lacrimal system injury because it is often present in the immediate post-injury period 2. the Jones I and Jones II tests will document the integrity of the system and localize the anatomic site of injury E. CSF rhinorrhea 1. may be present with cribriform injury 2. reflex watery rhinorrhea is common 3. the filter paper test or protein and glucose determinations should be done on any clear fluid draining from the nose F. diplopia 1. may be due to orbital blowout with entrapment, edema, or trochlear dehiscence 2. forced duction tests will help sort these out IV. Preoperative Workup A. a high index of suspicion for the possibility of nasoethmoid complex fracture is necessary; most of these patients will be multiply traumatized and this injury will be easily overlooked 1. document the intercanthal distance 2. determine the laxity of the lids 3. be alert to the characteristic clinical appearance B. preoperative ophthalmologic consultation is a must 1. 10% of all major periorbital trauma will also have an injury to the globe a. corneal laceration b. open globe c. hyphema d. detached retina 2. exam should include visual acuity, visual fields, indirect ophthalmoscopy, forced duction testing, and the Jones tests of lacrimal integrity C. thoroughly delineate the extent of all facial injuries so that the repair can be performed in an orderly fashion D. CT demonstrates the presence of all facial fractures and the extent of comminution of the complex, in addition to delineating the integrity of the cribriform plate and anterior cranial fossa E. always obtain preoperative photographs V. Treatment A. at the time of surgery, separate repairs are performed on the skeletal framework, the medial canthus, and the lacrimal system B. in the past, closed reduction with transnasal wiring over lead plates was the standard mode of treatment C. this approach has proved unsatisfactory 1. nasofrontal separation will remain unreduced 2. transnasal wiring placed via an external approach will lie anterior to the frontal process of the maxilla 3. local skin necrosis under the compression plates is common 4. a high incidence of postoperative telecanthus is seen 5. lacrimal dysfunction is not addressed D. the concept of early exploration and open reduction with direct repair of these injuries has evolved over the past 20 years in response to this high rate of complications and poor results E. it has become clear that accurate, stable fracture repair and canthal tendon alignment via an open approach yields better cosmetic and functional results F. the surgical approach can be achieved in several ways 1. through an existing laceration 2. bilateral "Z" incisions in the medial canthal region 3. "W" or "H" shaped incisions 4. bicoronal approach G. techniques of repair 1. the bony skeleton a. extensive comminution and fragmentation can be expected and each fragment must be identified and preserved b. midfacial and frontal fractures must be reduced and fixated prior to addressing the nasoethmoid complex c. the frontal process of the maxilla and the nasal bones should be aligned with the frontal bone and directly wired 1. Asch forceps aid reduction 2. a skin hook may be inserted behind impacted bones to provide additional traction d. the various bone fragments are aligned and directly wired to each other with small stainless steel wire or even chromic catgut where wiring is impractical 2. the medial canthal tendon a. unilateral injury 1. with adequate exposure, identification of the tendon is usually not difficult 2. it is often attached to a small fragment of lacrimal bone 3. occasionally, the tendon will be completely avulsed from bone 4. when comminution is minimal, and a small fragment remains attached to the tendon, some authors recommend direct reattachment of the tendon by wiring the bone fragment to the anterior lacrimal crest 5. superior stabilization is obtained, however, by wiring the bone fragment transnasally to the opposite anterior lacrimal crest 6. 0.3 or 0.4 mm stainless steel wire is passed through the tendon or bone twice; the ends are then passed transnasally through pre-drilled holes in the opposite anterior lacrimal crest with a curved awl or curved spinal needle 7. the ends are then twisted over a toggle wire b. bilateral injury 1. with bilateral displacement, the canthal tendons are wired to each other transnasally 2. two holes are drilled in each frontal process of the maxilla at the anterior lacrimal crest 3. again, wires are passed transnasally and tightened over a toggle wire 4. in this manner, the medial canthal tendons are drawn together 5. slight overcorrection is desirable 6. in the case of bilateral avulsions, the tendons are wired directly to each other at the level of the anterior lacrimal crest 7. the cut ends of the wires are carefully buried in the drill holes 8. removal of the wires is seldom necessary 9. some authors recommend wiring of the tendons transnasally over fashioned silastic buttons a. decreased scar from the compression b. the wires can be removed easily c. less chance of wire "cutout" 3. lacrimal repairs a. lacrimal system injuries should be repaired acutely because exposure is excellent and acute repair will often obviate the need for second procedures b. the Jones I and II tests will indicate the level of obstruction c. if lacrimal repairs are indicated, they should be completed prior to tightening of the transnasal wiring d. if doubt as to the integrity of the system still exists at the time of surgery, direct probing with lacrimal probes can localized obstructions and lacerations e. injuries are most often located in the lacrimal gland itself or at at the junction of the sac and nasolacrimal duct f. injuries here call for acute dacrocystrhinostomy g. in those cases where there is severe comminution a modified DCR may be performed a. silicone catheters are used to intubate the canaliculi, pass through the sac and into the nose either via a preexisting dehiscence or a rhinostomy b. the ends are ties together intranasally and left in place at least 6 weeks c. a new tract will mucosalize d. canalicular lacerations can also be closed over the silicone tubing with 10-0 nylon sutures VI. Postoperative Considerations A. prophylactic antibiotics are indicated in the perioperative period and should be continued for 5-7 days B. nasal splints are removed in 2 weeks C. external silastic buttons, if used, are removed with the wires in 4 weeks D. lacrimal silicone canulas remain in place at least 6 weeks E. close postoperatve follow-up by the ophthalmologist is indicated to ensure early detection and correction of diplopia, epiphora, dacrocystitis, etc -------------------------------------------------------------------------------- BIBLIOGRAPHY 1. Holt JE and Holt RH; "Reconstruction of the Lacrimal Drainage System"; Archives of Otolaryngology; 110:211-221,1984. 2. Holt, RH; "Nasoethmoidal Complex Fractures"; in Oto- laryngology-Head and Neck Surgery, Cummings et al eds.; volume 1 pp.314-319. 3. Hecht SD; "Evaluation of the Lacrimal System"; Ophthalmology;85: 1250-1258, 1978. 4. Holt RH and Holt JE; "Nasoethmoid Complex Injuries"; Otolaryngology Clinics of North America; 18:87-95; 1985. 5. Rowe NL and Williams J; Maxillofacial Injuries; Churchhill and Livingston, pp.376-400, 1985. 6. Converse JM and Hogan VM; "Open sky approach for reduction of naso-orbital fractures: Case report"; Plastic and Reconstructive Surgery;46:396-398,1970. 7. Gross CW, Teague PF, and Nakamura T; "Reconstruction following severe nasofrontal injuries"; Otolaryngology Clinics of North America; 5:653-665, 1972. 8. Jones LT; "an anatomical approach to problems of the eyelids and lacrimal apparatus"; Archives of Ophthalmology;66l:111-124, 1961. 9. Converse, JM;"Naso-orbital fractures and fractures of the Frontoethmoidal Region"; in Surgical Treatment of Facial Injuries; Converse and Kazanjian, eds., volume 1, pp.337-353, 1974. ----------------------------------END------------------------------------------