Upper extremity fractures are not uncommon, particularly with head on collisions. Such fractures can be caused by the driver bracing with the steering wheel or the passenger bracing him or herself on the dashboard at the time of collision.
Fractures can occur at the ball of the upper humerus, which can also become dislocated. This is seen on x-ray fairly easily because it is almost always displaced and is treated with closed reduction and a sling. A few cases may need surgical intervention.
The mid-portion or lower humerus is less likely to be fractured; there may also be open fractures, depending on how severe the impact. Fractures can extend into the elbow. Other elbow fractures involve fractures to the radius and ulna, proximal aspect. These can also be dislocated and can require closed reduction and a long arm cast to heal the fractured elements.
The distal radius and ulna can get fractured, sometimes leading to a fracture in the wrist joint itself. This is a common fracture in falls when people brace themselves following the slip and fall. Such a fracture is usually minimally displaced and can be treated with simple casting.
There can also be fractures of the wrist bones themselves and of the fingers and these are considered more common in automobile accidents.
A recent study looked at the mechanism of injury of upper extremity fractures in automobile fractures in order to see if better equipment can be designed to prevent this type of injury. In the study, about 3200 restrained drivers and 1230 front seat passengers were injured in a total of 9380 motor vehicle accidents. Five and a half percent received an upper extremity fracture. The hand was fractured 25 percent of the time, while the wrist was fractured 23 percent of the time. Fractures of the forearm happened 23 percent of the time with injuries to the elbow sustained 9 percent of the time, to the upper arm 10 percent of the time and to the shoulder 10 percent of the time.
The researchers found no differences in the amount and degree of upper extremity fractures when comparing drivers to front-seat passengers. Most of the upper extremity fractures occurred in front end collisions/head on collisions. Because it was found that the incidence of upper extremity fractures was mainly due to striking the dashboard, recommendations were made to install extra air bags or to pad the dashboard more fully.
The treatment of upper extremity fractures can be as simple as splinting a broken finger or casting a wrist and forearm. Elbow fractures need full arm casts and may need surgical intervention. Fractures of the humerus can be treated with a sling and support for the arm.
In many upper extremity fractures there is residual pain and limitations. Fractures that extend into the joint and involve the wrist joint are especially troublesome.