Anatomy of the scalp: The scalp is the soft tissue covering the fornix of the skull, which can be divided into frontoparietal-occipital and temporal parts according to the location.
I. Frontoparietal occipital region
Range boundaries: front to the supraorbital rim, back to the extra-occipital ridge and the superior collar line, and lateral to the temporal line. There are 5 layers of scalp structures in this area.
In order from the outside to the inside are
1, skin: thick and dense, containing sweat glands, sebaceous glands, lymph, blood vessels, hair follicles and hair.
2, subcutaneous tissue: numerous dense connective tissue separated by lobules, filled with fat, blood vessels and nerves, located between the subcutaneous and capillary tendon membrane.
3.Capillary tendon membrane: it is a white tough membranous structure. It is connected to the frontal muscle in front and the occipital muscle in the back, and laterally fused with the superficial temporal fascia, which can be considered as part of the cranial parietal muscle. This layer is closely connected to the skin by fiber bundles and loosely connected to the periosteum.
4.Subtenoid layer: It is a thin layer of loose connective tissue, between which there are many conduction vessels connected with intracranial venous sinus, which is one of the ways of intracranial infection and venous sinus embolism.
5.Periosteum: it is attached to the surface of the skull, tightly attached at the cranial suture and loosely attached in the rest of the body, so the subperiosteal hematoma can be limited.
II. Temporal part
The upper boundary of this department is the temporal upper line, and the lower boundary is the upper edge of the zygomatic arch. It is divided into 6 layers: skin, subcutaneous tissue, superficial temporal fascia, deep temporal fascia, temporalis muscle and periosteum in order from outside to inside. Between the superficial and deep temporal fascia, they are filled with fat. The periosteum is tightly bound to the temporal bone and cannot be easily separated.
Scalp injuries can be divided into.
(1) scalp abrasions: injuries to the epidermal layer of the scalp.
(2) skin contusion: the injury extends to the subcutaneous layer, visible subcutaneous swelling or bruising.
(3) Scalp laceration: fracture of the scalp tissue with varying depths.
(4) Scalp hematoma: classified according to the site as
(1) subcutaneous hematoma, which is usually small in extent and hard in texture.
(2) subcapsular hematoma, which is larger in scope and can spread to the whole head with obvious fluctuations.
(3) Subperiosteal hematoma, seen in infants and young children, is confined between the bony sutures, with a hard texture and a central depression of the scalp hematoma and a raised edge.
(5), scalp avulsion: a large area of scalp is avulsed from under the capitellar tendon membrane, or even the whole scalp is avulsed together with the temporal and frontal muscles. The trauma often has a lot of bleeding, and the exposed skull may cause necrosis or infection due to ischemia.
Treatment principles.
(1) Scalp abrasions and scalp contusions do not require special treatment.
(2) Scalp lacerations require suturing even for very small lacerations because of the rich blood supply to the scalp and the poor contractility of the scalp, so the bleeding is not easily stopped by itself. Because the epidermis of the scalp is prone to conceal bacteria, so the debridement should be thorough. However, the scalp is more resistant to infection, and generally within 48 hours or even 72 hours, the suture may still heal in one phase as long as the wound is thoroughly cleared.
(3) Scalp hematoma is usually bandaged with pressure and left to absorb on its own. If the hematoma is huge, it can be aspirated by puncture under strict sterilization and bandaged with pressure. Repeated puncture is necessary, but care should be taken to prevent secondary infection.
(4) Scalp avulsion requires hemostatic sutures and, in the case of large defects, surgical repair with shaping as appropriate.