Learning Objectives

By the end of this section, you should be able to:

Identify the bony landmarks of the humerus and their muscular attachments
Describe the articulations of the humerus at the shoulder and elbow
Recognize the clinical relevance of fractures at the surgical neck, shaft, and distal humerus

The humerus is a long bone of the upper limb that extends from the shoulder to the elbow.

Proximally, it articulates with the glenoid fossa of the scapula, forming the glenohumeral joint.
Distally, it articulates with the head of the radius and trochlear notch of the ulna at the elbow joint.

This bone serves as a site of muscular attachment, a lever for upper limb movements, and a conduit for neurovascular structures.

Proximal Humerus

The proximal humerus features:

Head – faces medially, upwards, and backwards; articulates with the scapula
Anatomical neck – separates the head from the tuberosities
Greater tuberosity – lateral; attachment for supraspinatus, infraspinatus, and teres minor
Lesser tuberosity – anterior/medial; attachment for subscapularis
Intertubercular (bicipital) sulcus – groove between tuberosities; contains the long head of the biceps brachii tendon
Surgical neck – distal to tuberosities; common site for fracture; closely associated with axillary nerve and posterior circumflex humeral artery

Mnemonic: “A lady between two majors.”

Fractures here risk injury to the axillary nerve, leading to deltoid paralysis and sensory loss over the regimental badge area.

Key features of the shaft:

Deltoid tuberosity – lateral surface; attachment of the deltoid
Radial (spiral) groove – posterior; transmits radial nerve and profunda brachii artery
Muscle attachments:
- Anterior: coracobrachialis, deltoid, brachialis, brachioradialis
- Posterior: triceps brachii (medial and lateral heads)

Injury to the radial nerve → wrist drop due to paralysis of wrist extensors. Sensory loss over the dorsal hand and the lateral 3½ fingers

Distal humerus landmarks:

Medial and lateral supraepicondylar ridges – origins for forearm muscles
Medial epicondyle – ulnar nerve passes posteriorly; easily palpable
Lateral epicondyle – origin of forearm extensors
Trochlea – articulates with the ulna
Capitulum – articulates with the radius
Coronoid, radial, and olecranon fossae – accommodate forearm bones during flexion/extension

Common in children; usually from a fall on an outstretched hand (FOOSH)
Risks: brachial artery injury → Volkmann’s ischemic contracture; nerve injuries (median, ulnar, radial, or anterior interosseous)
Gartland classification guides treatment:
- Type 1: minimally displaced – conservative cast
- Type 2: displaced, intact posterior cortex – usually surgical fixation
- Type 3: completely displaced – surgical fixation with K-wires