Soft Tissue Injury: Contusion, Hematoma, Swelling, Blisters, Tenting & Degloving Injuries Explained

It is important to know the types of soft tissue injuries

To assess the severity of the injury sustained by the patient since every injury type is due to different severity of trauma
Gives an idea about the management
Knowing the types of injuries help you communicate your findings with your team members and seniors

Contusions and hematomas

The most common closed soft tissue injuries you will see in your practice

Mechanism:

Fracture causes internal bleeding (at fracture site and in the skin) which gradually tracks to the skin and result in a bruise called contusion (contusion is the medical term for a bruise)

If blood collects at some place during this process , this blood collection is called hematoma

Pattern of contusion gives you an idea about the fracture location and the severity of soft tissue injury associated with it (e.g. calcaneal fracture result in contusion on sole of the foot)

Contusion takes several hours to appear after injury (so you may not see it at time of presentation to emergency department) and take several days to reach its full extent

Contusion stages:

Early stage: it start as reddish or purplish discoloration in the first 2 days with tenderness
Subacute stage: then turn to bluish or greenish color in the 5 days after as the body start to break down the blood
Healing stage: then transitions to yellowish or brownish as the body reabsorbs the broken down blood in the second week , and the size of the contusion decrease
Resolution stage: the bruise continue to fade and eventually disappears completely in the third week

Now regarding hematomas, hematoma appears as a lump on the injured site

Deep hematoma result in local swelling and tenderness, superficial hematoma may compromise skin viability (lead to skin necrosis) especially in skin areas that are thin and overlying a bone like pretibial region

Treatment: focus on treatment the fracture and the contusion or hematoma resolve by itself, if big hematoma then it might need to be drained or aspirated

Swelling

Inflammatory response to the injury which causes local increase in vascular permeability => swelling of the tissue with increase temperature

Swollen area has reduction in capillary circulation and reduced capacity to heal

Operating on swollen skin will have higher risk of wound dehiscence

Treatment of swelling is with RICE: rest, ice (cooling), compression, elevation

When swelling resolves, skin takes on wrinkled appearance and regains elasticity and that is when surgery is safely performed

Blisters

Blisters are formed due to rapid development of swelling in some area over the body

Mechanism:

The swelling cause an injury between the epidermis and dermis which lead those two layers to displace from each other and the space fills with serous fluid which is termed “clear fracture blister”, but if the underlying capillaries in the dermis are also injuries, the blister will fill with blood and termed “hemorrhagic blister”

Blisters are more famous in burned patients specifically second degree burns

Blisters resolve in two weeks after the injury

Treatment: Best if left undisturbed if possible, blister fluid is sterile but if deroofed then it get colonized with bacteria

If a surgical incision was done through a blister, then it takes longer for the skin to heal and carries higher risk of infection

Tenting

Skin pulled tightly over a prominent bone end, angulated fracture make prominent bone end that pulls the skin with it

Looks like a tent over the fracture area

Tented skin has impaired circulation with risk of necrosis and breakdown , this convert closed fracture to open fracture and increase chance of infection

Skin tenting is indication of urgent reduction of the fracture or the dislocation and maybe an indication of urgent surgery

Degloving

Mechanism: Result from significant shear forces causing separation of sub cut tissue from underlying fascial or osseous structures with collection of fat, blood and necrotic tissue

They most commonly affect the legs and are frequently associated with underlying fractures.

Common cause: soft tissue of a limb are crushed by wheels of a vehicle

Normal vascular supply arise directly from its underlying deep fascia, a degloving injury impairs the blood supply => skin necrosis after a while with infection and sepsis

It is unwise to make incisions through degloved skin because rate of wound dehiscence and infection are extremely high

Degloved skin is cool and can’t detect sensory input

Treatment: surgical exploration and excision of all non bleeding skin and fat and grafting or flapping the injuries after that