Bounds Emily J., Frane Nicholas, Jajou Lawrence, Weishuhn Luke J., Kok Stephanie J.
University of Illinois COM Peoria
Northwell Health at Hofstra School of Medicine Department of Orthopaedic Surgery
The humerus (arm bone) is the upper arm's only long bone. Humeral shaft fractures comprise 1-5% of all bony fractures (see . Oblique Humeral Shaft Fracture). These injuries have a bimodal age distribution. In young people, humeral shaft fractures are mostly caused by high-energy trauma. In older individuals, the damage may be caused by a low-impact force. The humerus articulates with the scapula proximally and the radius and ulna distally. The proximal humerus has a head, neck, and greater and lesser tubercles. The humeral head articulates with the scapula's glenoid fossa, forming the scapulohumeral joint, also known as the glenohumeral or shoulder joint. The anatomical neck of the humerus is the region around the humeral head proximal to the greater and lesser tubercles. The greater tubercle is the lateral border of the arm bone. The lesser tubercle is the arm bone's anterior projection. The intertubercular (bicipital) groove is the furrow between these tubercles. The surgical neck of the humerus is the narrow portion distal to the tubercles. This site is one of the most commonly involved locations in humeral shaft fractures. The deltoid tuberosity on the arm bone's lateral aspect is the deltoid's distal attachment site. The radial groove is a depression running posterolaterally on the middle third of the humerus. Middle-third humeral fractures can injure the radial nerve and profunda brachii artery, which pass in the radial groove. The humerus widens inferiorly, forming the lateral and medial supracondylar ridges. The lateral and medial epicondyles form at the distal end of the humerus. The humeral condyle comprises the lateral and medial epicondyles, the capitulum, the trochlea, and the olecranon, coronoid, and radial fossae. The arm has 2 compartments. The anterior compartment contains the brachial artery and vein, biceps brachii, brachialis, coracobrachialis, and musculocutaneous, median, and ulnar nerves. The posterior compartment houses all 3 muscle bellies of the triceps and the radial nerve. Historically, most humeral shaft fractures have been treated nonoperatively, especially with the development of the functional brace by Sarmiento et al. However, some humeral shaft fractures require early surgical intervention for better outcomes.
肱骨（上臂骨）是上臂唯一的长骨。肱骨干骨折占所有骨折的1%-5%（见“肱骨斜形骨干骨折”）。这些损伤具有双峰年龄分布。在年轻人中，肱骨干骨折主要由高能量创伤引起。在老年人中，损伤可能由低冲击力造成。肱骨近端与肩胛骨相连，远端与桡骨和尺骨相连。肱骨近端有一个肱骨头、肱骨颈以及大结节和小结节。肱骨头与肩胛骨的关节盂相连，形成肩肱关节，也称为盂肱关节或肩关节。肱骨的解剖颈是肱骨头周围、大小结节近端的区域。大结节是上臂骨的外侧边界。小结节是上臂骨的前部突起。结节间（肱二头肌）沟是这些结节之间的沟。肱骨外科颈是结节远端的狭窄部分。该部位是肱骨干骨折最常累及的部位之一。上臂骨外侧的三角肌粗隆是三角肌的远端附着点。桡神经沟是肱骨中1/3后外侧的一条凹陷。肱骨中1/3骨折可损伤位于桡神经沟内的桡神经和肱深动脉。肱骨向下增宽，形成外侧和内侧髁上嵴。外侧和内侧上髁在肱骨远端形成。肱骨髁包括外侧和内侧上髁、肱骨小头、肱骨滑车以及鹰嘴窝、冠突窝和桡窝。上臂有两个肌间隔。前肌间隔包含肱动脉和肱静脉、肱二头肌、肱肌、喙肱肌以及肌皮神经、正中神经和尺神经。后肌间隔容纳肱三头肌的所有三个肌腹和桡神经。从历史上看，大多数肱骨干骨折采用非手术治疗，尤其是随着萨米恩托等人发明的功能性支具的出现。然而，一些肱骨干骨折需要早期手术干预以获得更好的疗效。
