Blowout orbital fracture

Introduction to burst eyelid fracture Blowout fracture of the eye (blowoutfractureoftheorbit) refers to a special type of fracture that is exposed to violence in front of the eyelids, causing increased pressure and causing the lower wall of the sac to burst outward. basic knowledge The proportion of illness: 0.02% Susceptible people: no specific people Mode of infection: non-infectious Complications: anterior chamber hemorrhage iridocyclitis traumatic cataract vitreous hemorrhage

Cause of burst eyelid fracture

(1) Causes of the disease

The cause is almost always caused by external violence.

(two) pathogenesis

The mechanism of the formation of burst eyelid fractures is generally thought to be related to the sudden increase of fluid pressure in the sputum. Converse and Smith proposed that when the diameter of the wound is greater than 5.0 cm (ie larger than the diameter), the damage caused by the soft tissue on the eyelid can make The fluid pressure in the sputum suddenly increases, and the hydraulic conduction causes the tibia to break the weakest part of the sacral wall. The inner side wall (0.2-0.4 mm) and the bottom wall (0.5-1.0 mm) are the thinnest, so it is a bursting eyelid. The predilection site of the fracture, and the soft tissue in the iliac crest is invaded at the fracture or into the sinus cavity. There is fat protection around the eyeball, and there is generally no rupture of the eyeball. Smiths cadaveric injury test confirms the mechanism of the fracture. A person who has a simple orbital wall fracture without a sulcus fracture is called a hydraulic fracture.

Another type of thought is related to the direct action of the external force on the gingival margin. Fujino et al. proposed that the injury caused the injury to the lower edge of the iliac crest, pushing the bone sac and the periosteum to the posterior, resulting in a linear fracture of the sacral floor and tearing of the periosteum, and the soft tissue was squeezed into it. In the maxillary sinus, when the injury is stopped, the fracture base is rapidly reset, and the soft tissue is recovered slowly, so it is often embedded in the fracture. If the external injury is large, the fracture will occur after the linear fracture occurs at the fundus. The trailing edge of the bone piece in front of the line pushes the leading edge of the bone piece behind the fracture line back, causing overlapping multiple pieces of fracture. After the injury has disappeared, the fracture can not be reset, which can cause the defect. And the periorbital tissue edema, the fluid pressure in the sputum increased, the contents of the sputum were squeezed, and under the dual action of gravity, the soft tissue inside the sac was squeezed into the fracture area, and even invaded into the maxillary sinus, as shown in Figure 1.

Through the establishment of animal models to study the mechanism of eyeball invagination in orbital fractures, the results show that the reasons for eyeball invagination are as follows:

1. The base of the sacral floor and the sacral wall are split and moved outward, and the volume of the bony cavity is enlarged, which is the main cause of eyeball invagination.

2. The bone wall is ruptured, and the soft tissue in the sac is inserted into the maxillary sinus and ethmoid sinus, and the soft tissue volume in the sac is reduced.

3. Atrophy of the fat and tissue in the muscle cone.

4. Extraocular muscle and soft tissue damage forms scar and scar contracture.

Burst eyelid fracture prevention

Home security: Seventy-five percent of falls occur in their homes, especially in bathrooms, kitchens and more. Providing a safe home environment is very important to reduce fracture production. Prevention of this type of fracture is more common.

To strengthen the publicity knowledge of eye protection, outdoor work should always be attentive, obey traffic laws, and avoid eyelid fractures and systemic injuries caused by car accidents.

Burst eyelid fracture complications Complications, anterior chamber, iridocyclitis, traumatic cataract, vitreous hemorrhage

Burst eyelid fractures may be associated with eyeball contusions such as horns, scleral laceration, anterior chamber hemorrhage, pupillary dyskinesia, traumatic iridocyclitis, iris root detachment, traumatic cataract, lens dislocation, vitreous hemorrhage, retina Oscillation, preretinal hemorrhage, serrated edge separation, retinal detachment and optic nerve damage, traumatic glaucoma, etc., so when patients with burst eyelid fractures should be examined, a comprehensive examination of the eye should be performed.

Common symptoms of ruptured orbital fractures

1. Soft tissue swelling and blood stasis around the eyelids and eyelids: It can appear within a few hours after the injury. The upper and lower jaws are blue-purple and can be accompanied by sputum pronunciation.

2. Eye movement limitation: mainly restricted by up-regulation, accounting for 77%, and 28% of patients with positive traction test. The reasons for eye movement limitation are:

1 extraocular muscle incarceration;

2 eyes after blunt trauma, resulting in this part of the adipose tissue edema, often accompanied by venous rupture, so that the fibrous connective tissue becomes tense, causing eyeballs and forced movement disorders, according to the degree of eye movement, the degree of reduction of the fracture to determine the fracture The location of the fracture is mainly in the above-mentioned, the fracture site is a linear fracture from the inferior temporal sulcus to the nasal anterior aspect, and most of the fractures are in the shallower part; in the following cases, the fracture is the main one. The linear fracture of the inferior sulcus to the posterior aspect of the nasal side, and the posterior fracture; the upper and lower rotation are limited, the fracture is a large fracture centered on the infraorbital sulcus. The relationship between fracture and ocular dyskinesia is as follows: the vertical movement of the eyeball is the most common, accounting for 58.86%. It is caused by the upper wall and/or the inferior tibiofibular fracture. The lower wall accounts for 95.15%, mostly the middle and posterior segment fractures. The sacral tissue is severely exfoliated, and the horizontal dyskinesia accounts for 20%. It is caused by the internal wall of the iliac crest or (and) the external wall of the iliac crest, of which the inner wall accounts for 77.14%, but the sacral tissue is less prolapsed and the fracture range is large; the mixed direction dyskinesia (such as Outside, outside, Upper and lower inner etc.) accounted for 17.14%, found mainly in the lower wall while the fracture; eye fixation (4%) found in orbital apex syndrome, associated with traumatic brain injury.

3. Early or late eyeball retraction: average invagination of 4.6mm, accounting for about 23%, the reasons are:

1 humerus and periosteal rupture, the adipose tissue in the iliac crest is inserted into the maxillary sinus or ethmoid sinus

2 volume increases;

3 intraorbital hematoma compression, inflammatory lesions cause necrosis of fat in the sputum;

4 The extraocular muscle is incarcerated in the fracture joint, and the long-term eye muscle is shortened and fibrotic, so that the eyeball is fixed in the receding position. The eyeball invagination is often accompanied by pseudo ptosis, and the sacral sulcus deepens and splits the sac. The path is shortened and other signs.

4. Vertical diplopia after injury: can appear several days after the swelling subsides, the complex distance increases when looking upwards or downwards, because the inferior rectus muscle, the inferior oblique muscle or its fascia is invaded at the fracture; or the eye Fat and fibrous tissue near the external muscles caused by edema or hemorrhage caused by ocular dyskinesia, or the extraocular muscles may be out of balance due to eyelid deformation, damage to the extraocular muscles or the nerves that innervate the extraocular muscles, causing diplopia. About 70% of the symptoms are considered.

5. The skin sensation of the underarm nerve distribution is reduced: about 23%, which is caused by the injury of the infraorbital nerve caused by the inferior sulcus (tube) fracture.

6. Incarceration of the extraocular tissue: about 53%, mainly for the inferior rectus muscle and/or the inferior oblique muscle or surrounding tissue embedded in the fracture.

7. The first eye position is inclined: it is more obvious when looking upwards.

8. Sometimes there may be eyelid emphysema (12%) and post-balloon bleeding (2%).

9. Perceptual sensation or paresthesia of the skin and gums in the infraorbital area: mostly due to injury to the infraorbital nerve due to a fracture of the middle of the sacral floor.

According to the patient's complaint, the injury should be analyzed and a detailed examination should be carried out. If the patient is awake, the patient often complains of diplopia, especially when looking up or down. It can also be swollen due to eyelids after injury, or the eyeball is invaded or combined with serious eyeballs. Contusion, visual function decline is obvious without double vision, should wait for the edema to disappear, check the eye movement of both eyes is restricted, and then use the pull test to judge the tissue incarceration or paralysis, the pull test should be vertical and rotary motion; or use 2 The gingival sac is clamped to the outer edge of the cornea for the lifting eye test and the trapping test. If the pulling test is positive, it is mostly caused by the incarceration of the extraocular muscle or the iliac crest; if the movement is not restricted, the pulling test is negative. Because of the damage of motor nerve or eyelid hemorrhage, edema, the degree of eye movement limitation can be judged by this test, and the effect of eyeball retraction correction can also be predicted. The most ideal and most accurate examination is X-ray. Film and CT scans, CT scan can be used for orbital axis and coronal position, scanning layer thickness is 5.0mm or 2.0mm, layer spacing is 5.0mm or 2.0mm, using bone window and soft tissue window to observe, combined with clinical special It is not difficult to make a diagnosis.

Examination of burst eyelid fracture

Simple burst eyelid fractures do not require special laboratory tests, and may be subject to laboratory tests for other parts of the body.

X-ray and CT examination are important methods for diagnosing burst eyelid fractures. More than 90% of orbital fractures can be diagnosed by X-ray and CT examination. According to the X-ray film and CT scan, combined with the above clinical features, it can be determined. The location, shape, extent of the fracture of the sacral floor, the presence or absence of sputum content, and whether or not the sacral, external, and upper wall fractures are combined. If necessary, a positive contrast agent can be injected at the base of the iliac crest to show the fracture-destroyed area. In the typical case X On the ray and CT photos, the top of the maxillary sinus can be seen to deform, the bottom of the sac is sinking, the soft tissue in the sac is trapped in the shadow of the maxillary sinus and the shadow of the broken bone in the sinus. The CT coronary scan can classify the relationship between the inferior rectus muscle and the fundus. :

1 free type: the muscle bundle is not attached to the bone wall;

2 hook type: the displacement of the swollen muscle part, attached to the fracture area;

3 Collapse type: the swollen lower rectus muscle bundle is sandwiched between the broken bones. CT examination can also divide the burst fracture into the sacral type, teardrop type, sacral type and composite type 4.

Diagnosis and diagnosis of burst eyelid fracture

diagnosis

Diagnosis can be performed based on clinical performance and laboratory tests.

Differential diagnosis

Identification with a blown fracture.

Stroke fractures, also known as sputum bursts, were reported in Lang, as early as the case of a case evaluation of eyeball depression and diplopia due to the meaning of sacral fracture. King (1944) reported that Smith (1957) officially named the impact fracture. (blow-outfracture). The blown fracture is when the eye is suddenly slid by the blunt instrument, and the eyeball suddenly shifts backwards. The pressure in the sac is so sharp that the rupture of the inferior wall or the inner wall is severe. The fracture piece and the sputum content (fatty muscle) are trapped in the maxillary sinus or The ethmoid sinus is often accompanied by a hematoma. The subarachnoid congestion in the subarachnoid area is numb; the eye movement is limited and diplopia appears.

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