Scalp injury


Introduction to scalp injury

The scalp is a surface barrier against external violence in the brain. It has greater elasticity and toughness and has strong resistance to stress and tension. Therefore, violence can be transmitted to the brain through the scalp and skull, causing damage to the brain tissue, while the scalp is intact or slightly damaged. The structure of the scalp is obviously different from that of other parts of the body. The surface layer is thick and bloody, and the subcutaneous tissue structure is dense. There are short fibers separating the surface layer, the subcutaneous tissue layer and the cap-like aponeurosis layer. The Trinity is not easy to separate. In the meantime, it is rich in fat particles and has a certain protective effect. There is a loose connective tissue gap between the cap-shaped diaphragm and the periosteum of the skull, so that the scalp can slide, so it has the effect of buffering external violence. Scalp injury is the most common type of primary craniocerebral injury. It can range from slight abrasion to avulsion of the entire scalp. The significance of this is that the scalp injury contributes to the location and severity of the brain injury. Scalp injury often combined with different degrees of skull and brain tissue damage, can be used as an invasion portal for intracranial infection and cause secondary lesions in the brain, so the reconstruction after scalp injury has been paid more and more attention.

basic knowledge

The proportion of sickness: 0.003%--0.005% (incidence rate is about 0.003%--0.005%, the occupation rate of this disease is about 10% in car accidents and fighting injuries)

Susceptible people: no specific population

Mode of infection: non-infectious

Complications: scalp infection, subarachnoid abscess, osteomyelitis, shock


Cause of scalp injury

Strike and collision (20%):

The blow is a moving foreign object that hurts the head. Because the speed and size of the wound are different, it can cause different damages. For example, the volume of the wound is large and slow, often causing scalp contusion and hematoma, and the volume is high. The scalp is contused and lacerated. The small size and fast speed often cause small laceration of the scalp, and often accompanied by penetrating head injury.

Collision is a moving head that hits a foreign object. It is common in car accidents, falls, and fall injuries. When it hits a wide and flat foreign object, if it is slow, it often causes scalp contusion and hematoma, such as a fast collision. Often caused by scalp laceration and adjacent scalp contusion and skull fracture, and collision with a narrow area of sharp foreign objects, easy to cause scalp laceration.

Cutting and stamping (25%):

Cutting is caused by sharp objects acting on the scalp, often causing neat scalp lacerations. Punching is caused by sharp foreign objects acting on the head, often causing regular or irregular scalp lacerations, often accompanied by Open craniocerebral trauma.

Friction and involvement (15%):

Friction is caused by violent tangential action on the head, often causing scalp abrasions and contusions. In severe cases, some scalp avulsions can be caused. The traction is caused by the strong pulling force of the scalp, mainly found in female workers. The cockroach is entangled in the rotating wheel, often causing severe avulsion of large scalp or full scalp.

Extrusion (10%):

It is caused by the violence in the opposite direction at the same time, which is common in the slab extrusion and birth injury. In addition to causing scalp contusion and hematoma in the affected area, it often combines skull fracture or brain trauma.


Scalp injury prevention

Pay attention to the safety of the action, do the necessary protective measures for the head, and fasten the seat belt by car, such as riding a motorcycle with a helmet.


Scalp injury complications Complications, scalp infection, decidual subarachnoid abscess, osteomyelitis

Scalp infection

Acute scalp infection is mostly caused by improper treatment in the initial stage of injury. It often occurs in the subcutaneous tissue. There are red, swollen, hot, painful, localized, swollen and tender lymph nodes in the ear or under the occipital plexus. Cap-like aponeurosis is connected, so the tension in the inflammatory zone is high, the patient often suffers from pain, accompanied by symptoms such as chills and fever in the whole body. In severe cases, the infection can invade the skull or the cranium through the blood vessel. The principle of treatment is to give antibacterial in the early stage. Drugs and local hot compresses, when the abscess is formed later, the incision and drainage should be performed, and the systemic anti-infective treatment should be continued for 1 to 2 weeks.

2. Capular subdural abscess

The decidual subarachnoid tissue is loose, and the suppurative infection is easy to spread, but it is often limited to the attachment edge of the aponeurotic aponeurosis. The abscess originates from scalp hematoma infection or skull osteomyelitis after injury. In children, occasionally due to scalp infusion or puncture, Patients with capsular subarachnoid abscess often show swelling of the scalp, pain, orbital edema, and may be accompanied by systemic toxic reaction in severe cases. Treatment of decidual subdural abscess should be performed in addition to the application of antibacterial drugs.

3. Osteomyelitis

Acute osteomyelitis in the cranial cap area, mostly manifested as scalp edema, pain, local tenderness, edema mass may occur when the infection spreads to the periosteum of the outer skull of the skull. The early stage of skull osteomyelitis is easy to ignore, and the X-ray film is only in the After 2 to 3 weeks of infection, obvious signs of decalcification and destruction can be seen. Chronic skull osteomyelitis often manifests as a long-lasting sinus, which repeatedly breaks through pus and sometimes discharges dead bone fragments. X-ray plain film is more likely to show the uneven bone-damage area of worm-like density, and sometimes there is a high-density flaky dead bone image, which is too long for chronic skull osteomyelitis, and bone can also appear around the damaged area. Hardening and hyperplasia can be diagnosed by X-ray film. The treatment of skull osteomyelitis should be performed at the same time as antibacterial therapy to remove the diseased bone that has lost vitality and no blood supply.

4. Shock

The scalp avulsion injury is due to large wounds and hemorrhage, which is prone to shock. In the infant, the subarachnoid hematoma is severe throughout the head and the hematoma border and the aponeurosis of the cerebral aponeurosis. When bleeding occurs, it can be complicated by shock.


Symptoms of scalp injury Common symptoms Trauma scalp avulsion scalp laceration scalp subcutaneous hematoma intracranial hemorrhage severe pain subcutaneous hematoma scalp flat crack skull fracture shock

1. Scalp laceration: The scalp is a specialized skin with a large number of hair follicles, sweat glands and sebaceous glands. It is easy to hide dirt and bacteria, which is easy to cause infection. However, the scalp blood circulation is very rich, although the scalp is lacerated, as long as It can be thoroughly debrided in time, and infection is rare. In each layer of the scalp, the cap-like aponeurosis is a tough aponeurosis, which is not only an important structure for maintaining scalp tension, but also a defense against superficial infection. The barrier, when the scalp laceration is shallow, does not damage the cap-like aponeurosis, the rupture is not easy to open, the vascular end is difficult to retract and stop bleeding, but the bleeding is more, if the aponeurotic rupture of the rupture, the wound is obviously cracked, the injury The vascular end of the blood vessel retreats with the wound, self-coagulation, and therefore less bleeding.

(1) scalp simple laceration: often due to sharp stab wound or cut injury, the crack is relatively straight, the wound edge is neat and no defect, the depth of the wound varies with the injury factor, except for a few sharp instruments directly penetrating or licking Outside the cranial incision, causing open head injury, most of the simple laceration is limited to the scalp, sometimes deep into the periosteum, but the skull is often intact and not accompanied by brain damage.

(2) complicated schizophrenia: often caused by blunt injury or head collision on foreign objects, the crack is irregular, the wound edge has contusion marks, and there is still fiber connection between the internal cracks, which is not completely broken off. There is no "organizational frustration" phenomenon. In forensic identification, if the scalp contusion and laceration wounds appear "tissue collapse", it is often suggested that it is caused by metal or angular weapons. The shape of the wound often reflects the size of the wound. And shape, such wounds are often accompanied by skull fractures or brain damage. In severe cases, comminuted sag fractures or hole fractures can be penetrated into the skull. Therefore, foreign bodies such as hair, cloth dust or sand are often embedded, which may cause infection. When checking the wound, be careful not to remove the foreign matter embedded in the skull to avoid sudden bleeding.

(3) scalp laceration: most of the violent effects in the oblique or tangential direction are caused by the scalp. The torn scalp is often tongue-shaped or lobed, often with a pedicle connected to the head, and the scalp is generally lacerated. Not accompanied by skull and brain damage, but not always, occasionally there are skull fractures or intracranial hemorrhage, such patients have more blood loss, but less to the extent of shock.

2. scalp avulsion: scalp avulsion is a serious scalp injury, almost because the woman with stubble accidentally drags the hair into the rotating wheel, due to the epidermis, The subcutaneous tissue layer and the cap-like aponeurosis layer 3 are closely connected together, so under the strong traction, the scalp is often avulsed from the full layer of the decidual aponeurosis, and sometimes the partial periosteum is also avulsed, so that the skull is exposed. The extent of scalp avulsion is related to the area of the hair root involved. In severe cases, it can reach the coverage area of the entire cap-like aponeurosis, the anterior to the upper eyelid and the nasal root, and then to the hairline, both sides of the auricle and even the cheek, the patient A large amount of blood loss can cause shock, but less combined with skull fracture or brain injury.

3. Scalp hematoma: The scalp is rich in blood vessels. After a blunt blow or collision, the blood vessels in the tissue can rupture and the scalp is still intact. The scalp hemorrhage is often in the subcutaneous tissue, under the aponeurosis. Subperiosteal hematoma formation, its location and type help to analyze the mechanism of injury, and can estimate the damage of the skull and brain.

(1) Subcutaneous hematoma: The subcutaneous tissue layer of the scalp is the blood vessel of the scalp, the site where the nerves and lymph are collected. It is prone to hemorrhage and edema after injury. Because the hematoma is located between the surface layer and the aponeurosis, it is restricted by the subcutaneous fibers. Special performance: small size, high tension, pain is very significant, the center of the percussion is slightly soft, the surrounding bulge is hard, often mistaken for a depressed fracture.

(2) subarachnoid hematoma: the lower layer of the aponeurotic aponeurosis is a loose layer of cellulite with a vascular connection between the scalp vein and the skull vein and the intracranial sinus. When the head is subjected to oblique violence. The scalp violently slides, causing tears between the layers of the blood vessels, bleeding is easy to spread, often causing massive hematoma, so its clinical features are: a wide range of hematoma, severe hematoma boundary and cap-like aponeurosis attachment edge, before To the eyebrow arch, after the occipital trochanter and the upper line, the two sides of the sacral bow, just like a hat on the patient's head, hematoma tension is low, the fluctuation is obvious, the pain is light, there is anemia appearance, the infant is huge A subarachnoid hematoma can cause shock.

(3) subperiosteal hematoma: subperiosteal hematoma of the skull, except for infants due to birth injury or fetal head attracting midwifery, usually accompanied by linear fracture of the skull, the source of bleeding is mostly caused by platelet hemorrhage or due to periosteal stripping. The blood accumulates between the periosteum and the surface of the skull. The clinical feature is that the hematoma perimeter terminates in the suture. This is because the skull is embedded in the suture during the development of the skull, so there is less subperiosteal hematoma. In the case of a bone fracture, unless the fracture line spans two skulls, the hematoma will still stop at the suture of the other skull.


Scalp injury examination

1, the skull X-ray film examination.

2, waist wear: understand the degree of subarachnoid hemorrhage and intracranial pressure. Severe traumatic intracranial hypertension or obvious signs of cerebral palsy are contraindicated.

3. CT scan.

4. MRI.


Diagnosis of scalp injury

Differential diagnosis

Scalp laceration

Due to sharp injury, blunt injury, such as cutting injury or chopping, high-speed sharp-point projection injury, head impact injury, etc., the head has severe laceration, accompanied by varying degrees of bleeding, due to scalp blood vessels, After the blood vessel is ruptured, it is not easy to close by itself, even if the wound is not bleeding much, the edge of the wound is sharp and the wound is not neat, and the line may be straight or irregular.

2. Scalp hematoma

Often associated with scalp contusion or an indirect sign of deep skull fracture.

(1) subcutaneous edema: The hematoma is located between the superficial scalp and the aponeurotic aponeurosis. The hematoma in this layer is more limited, and the hematoma is often at the point of violence.

(2) Capular subdural hematoma: The hematoma is located between the aponeurotic aponeurosis and the periosteum. The hemorrhage is diffused in the decidual decidual space. It is not easy to be confined and spread widely. The hematoma is wide. When it is severe, the hematoma boundary is spread throughout the skull. Consistent with the attachment edge of the aponeurotic aponeurosis, the palpation has obvious fluctuations. In infants and young children, when there is a lot of bleeding, it can be accompanied by shock.

(3) subperiosteal hematoma: more common in the blunt injury after the head deformed significantly, the hematoma is located between the periosteum and the skull outer plate, the hematoma does not exceed the cranial suture.

3. Scalp avulsion

The scalp is mostly avulsed from under the aponeurosis or under the periosteum. The boundary of the entire scalp avulsion is the same as that of the cap-like aponeurosis. The anterior to the eyelid and the nasal root, the posterior to the upper line and the hairline, both sides to the ankle, due to The wound is large, the bleeding is many, and it is easy to have shock.