Seat belt syndrome

What is Seat belt syndrome?

Seat belt syndrome(seat belt injuries) also known as lap belt complex is a classical injury pattern that a person, who was wearing seat belt in an improper position, suffers after a motor vehicle collision. The classical injuries include

1) Abdominal wall contusion (seat belt sign on torso)

2) Intra-abdominal visceral injury (e.g. small bowel perforation/mesenteric tears/colon tears) and/or

3) Spine injuries (e.g. flexion-distraction chance fractures of lumbar spine, cervical spine fractures)

how Seat belt syndrome are divided?

The injuries can be divided into

1.obvious injuries and 2.covert (hidden) injuries.

Obvious injuries 

1. Chance fracture of lumber spine

     Flexion-distraction injury (disruption of articular facets of vertebrae)

2. Dislocated knee joint

     From blow to the dashboard

3. Head injury 

    Collision of head with steering

Covert (hidden) injury 

1.Duodenal rupture.

  Most common injury following blunt trauma to abdomen is hollow viscus injury. Mesenteric tears are common than direct bowel injuries. Duodenum is most fixed part of small bowel, lacks mesentery and is retroperitoneal. The mobile parts are able to withstand high pressure and resultant damage.

2. Popliteal artery disruption.

  Occurs secondary to knee dislocation from dashboard injury

3. Cervical spine injury 

  Flexion distraction/whiplash injury.

4. Pancreatic and aortic injuries.

  These are fixed retroperitoneal structures and as a rule, fixed part are more damaged in blunt abdominal trauma

A patient of seat belt injury underwent laprotomy

Now we will solve two questions about Seat belt syndrome.

A 45 year old male suffers from RTA and is brought to emergency. On inspection, he has seatbelt mark on abdomen. The most likely injured organ is?

A) Liver

B) Spleen

C) Duodenum

D) Kidney 

E) Transverse colon

Correct: C (Duodenum)

A 45 year old man while driving at speed of 70 km/hour suddenly loses control due to tire bursting and had a collision with a tree on side of road. Which of following is most likely a "deceleration" injury?

A) Posterior dislocation of shoulder 

B) Rupture of stomach

C) Rupture of aortic valve

D) Mesenteric avulsion 

E) None of the above

Correct: D (Mesenteric avulsion)

Explanation

Mesenteric injury is the of the commonest injury encountered in blunt torso trauma from decelerating motor vehicle injury. It is also seen in seat belt syndrome. Bleeding from the torn vessel can result in hemoperitoneum, hence requiring operative exploration. Also note that horizontal tears in mesentery can devascularize the bowel (if tear involves the vascular arcades). Hence a high index of suspicion should be present following abdominal wall contusions and the patients frequently monitored. A bucket handle injury is a type of mesenteric injury of the intestine in which intestine itself separates from the mesentery, leaving a devascularized segment of bowel that looks like the handle on a bucket.