What nerve is most easily injured in humeral surgical neck fracture

Fracture of the surgical neck of the humerus is most likely to damage the axillary nerve.

The anatomical position of the surgical neck of the humerus is special, and important nerves pass around it. The axillary nerve passes closely to the surgical neck of the humerus. When the fracture occurs here, the displacement and hematoma of the broken end of the fracture are easy to cause direct compression and traction of the axillary nerve. The axillary nerve mainly innervates the deltoid muscle and the small round muscle, and is responsible for the motor function of the lateral shoulder and the sensation of the lateral shoulder and the upper limb. Axillary nerve damage can lead to deltoid paralysis and shoulder abduction dysfunction, characterized by inability to abduct the affected arm and loss of the normal rounded shape of the shoulder to a square shoulder. It can also be accompanied by hypoesthesia or loss of sensation in the lateral shoulder and upper arm. During the treatment of humeral surgical neck fractures, close attention should be paid to the damage to the axillary nerve. Detailed neurological evaluation, including motor and sensory function tests, should be performed promptly. If there is axillary nerve injury, it is necessary to formulate appropriate treatment plan according to the specific degree and time of injury, such as observation and waiting for recovery, nerve repair surgery, etc., in order to recover nerve function as much as possible and reduce the occurrence of sequelae.