Final answer:
A common injury following a fall onto an outstretched hand in individuals over 40 years old is a Colles fracture of the distal radius, which leads to a 'dinner fork' deformity and is especially prevalent in those with osteoporosis.
Step-by-step explanation:
Injury in patients greater than 40 years old after a fall braced by an outstretched arm often results in specific types of fractures due to the force transmission up the limb. One frequent injury is a Colles fracture of the distal radius, which is a complete transverse fracture driving the distal fragment of the radius posteriorly and superiorly. This is characterized by a 'dinner fork' deformity of the forearm above the wrist.
Colles fractures are the most common type of forearm fracture and occur predominantly in older individuals over the age of 50, particularly in those with osteoporosis. This type of fracture is commonly caused by high-speed falls during activities such as snowboarding or skating as well as simple falls in those with weakened bones due to osteoporosis. Immediate medical attention is necessary to manage the fracture and prevent complications such as nerve damage or compromised blood flow to the forearm.