Humerus fracture — Medicine Library

Summary

Humerus fractures can result from direct or indirect trauma. They are classified by location into proximal humerus fracture, humeral shaft fracture, and distal humerus fracture. Proximal humerus fractures most commonly occur in older adults, while supracondylar fractures (a type of distal humerus fracture) are most common in children. Clinical features include pain, soft tissue swelling, and visible deformity. Nondisplaced, closed fractures are typically managed with a sling or splint. If there is evidence of neurovascular compromise or in the case of open fractures, operative management is usually required.

Epidemiology

Proximal humerus fractures are the most common humerus fractures.
Incidence increases with age.
Sex: ♀ > ♂

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Direct or indirect trauma
- Falls with axial loading on an outstretched hand (most common cause) [2]
- Motor vehicle accidents
- Violent seizures
- Direct blow to the back of the humerus
Pathologic fractures: : e.g., Paget disease, metastatic bone disease (less common)

Classification

Proximal humerus fracture

Proximal humerus fractures are common in older adults and typically occur between the major segments of the proximal humerus. [2]
Neer classification: Fractures are classified as one- to four-part fractures, depending on the number of displaced fracture segments. [3]

$Proximal humerus fracture$ $Proximal humerus fracture$

Humeral shaft fracture

Humeral shaft fractures are further classified based on location. [2]

Proximal humeral shaft fracture
Middle humeral shaft fracture
Distal humeral shaft fracture

$Humerus fracture$

Distal humerus fracture

Distal humerus fractures, of which there are many subtypes, are a type of elbow fracture. See “Forearm fractures” for other fractures with elbow involvement.

Supracondylar fracture
A fracture of the distal humerus proximal to the epicondyles

The most common pediatric elbow fracture [4]
Transcondylar fracture
Intercondylar fracture
Condylar fracture
Epicondylar fracture
Capitellum fracture
Trochlea fracture

$Extension-type supracondylar humeral fracture$ Humerus

**Proximal humerus fracture**
X-ray left shoulder (AP view)
A three-part fracture (Neer classification) of the surgical neck (white arrows) of the proximal humerus involves the greater tuberosity (black arrow). There is lateral angulation of the humeral shaft.

Source: “ProxHumeralFracture” by James Heilman, MD, Wikimedia Commons, licensed under CC BY-SA 4.0. Modifications: removal of the red arrow. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 4.0.

Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.

**Humerus fracture**
X-ray (posteroanterior view) of the humerus
Fracture of the humerus into multiple fragments. The overlay highlights the points of fracture belonging together in green and red. White-filled overlay highlights the ulna. White outline highlights the humerus. White dashed outline highlights the radius.

Source: © IMPP

**Extension-type supracondylar humeral fracture**
X-ray elbow (lateral view) of a child with a history of recent trauma
A comminuted supracondylar fracture of the distal humerus (H) shows posterior displacement of the distal fragment and growth plate involvement (white arrow). Joint effusion is present, with elevation of the lucent posterior fat pad (white arrowheads).
H: humerus; R: radius; U: ulna

Source: “Supracondylar09” by James Heilman, MD, Wikimedia Commons, licensed under CC BY-SA 3.0. Modifications: Removed black arrow. Removed the black letters.. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.

**Humerus**
The humerus from a ventral (left), dorsal (center), and lateral (right) view.
The anatomical and surgical necks of the bone are marked with dashed lines.

© AMBOSS

Clinical features

Severe local pain: exacerbated during palpation or movement at shoulder or elbow
Local swelling (edema or bleeding), deformity, and/or crepitus
Shortening of the arm (associated with displacement)
Neurovascular complications such as radial nerve palsy (see “Complications” below)
See “Signs of fracture.”

The radial nerve runs through the radial sulcus of the upper arm and is especially at risk in fractures of the middle third (midshaft) of the humerus!

Diagnosis

Clinical evaluation [2]

Any findings that suggest neurovascular injury or open fracture should prompt urgent orthopedic consultation.

Neurovascular exam
- Assess radial and ulnar artery pulses and capillary refill time.
- Evaluate for median nerve injury , radial nerve injury , and ulnar nerve injury.
Skin exam: Evaluate for laceration, tearing, and tenting.

Pinch sign (anterior interosseous syndrome) Hand of benediction Radial nerve neuropathy Ulnar nerve neuropathy

Imaging [2]

X-ray

Imaging for humerus fractures typically includes x-ray views of the humerus, shoulder, and elbow.

Views
- Shoulder: true anteroposterior, trans-scapular lateral (Y view), and axillary lateral
- Humerus: anteroposterior and lateral
- Elbow: anteroposterior and lateral, as well as oblique view as needed
Findings
- Radiographic fracture signs, fracture fragments, displacement, angulation, and/or dislocation
- Visible fat pads in
  elbow views suggest an intraarticular
  fracture.
  
  Posterior fat pad sign: a radiographic finding caused by an elbow joint effusion; results in the presence of a lucent crescent in the olecranon fossa on a lateral x-ray view of the elbow
  
  Anterior fat pad sign (sail sign): a radiographic finding caused by an elbow joint effusion; results in the presence of a convex lucent crescent in the coronoid fossa on a lateral x-ray view of the elbow

A visible anterior fat pad may be normal, but a visible posterior fat pad is always abnormal. [2]

$Proximal humerus fracture$ $Proximal humerus fracture$ $Humerus fracture$ $Humeral unicameral bone cyst (UBC) with pathological fracture$ $Extension-type supracondylar humeral fracture$ $Distal humerus fracture$ $Anterior and posterior fat pad signs in supracondylar humerus fracture$

Advanced imaging [2]

CT: indicated in preoperative planning for complicated fractures, assessment of associated injuries, and inconclusive x-ray findings
CT angiography: indicated for suspected vascular injury
MRI: may be indicated for diagnosis of associated tendon/ligament injuries (e.g., rotator cuff injury)

**Pinch sign (anterior interosseous syndrome)**
The anterior interosseous nerve is a pure motor branch of the median nerve. It supplies the flexor pollicis longus, the radial half of the flexor digitorum profundus (and the pronator quadratus).
Pinch sign: an inability to flex the DIP of the index finger and IP joint of the thumb when asked to make an “OK” sign that is caused by a lesion or entrapment of the anterior interosseous nerve

© AMBOSS

**Hand of benediction**
An inability to flex the index and middle fingers at the MCP and IP joints and an inability to oppose the thumb.
The hand of benediction is an active sign and is only seen when the patient is asked to make a fist. It indicates a paralysis of the thenar muscles (except the adductor pollicis), the flexor digitorum superficialis, and the radial half of the flexor digitorum profundus caused by a proximal lesion of the median nerve (above the elbow).
Also depicted is atrophy of the thenar muscles, which is seen in chronic median nerve palsy.

© AMBOSS

**Radial nerve neuropathy**
Motor deficits:
- Wrist drop: inability to extend (dorsiflex) the wrist
- Inability to extend the fingers at the MCP joints
Sensory deficits:
- Dorsal aspect: radial 2½ fingers (less commonly, 3½ fingers), excluding the tips of the 2^nd and 3^rd fingers. The 1^st web space is the autonomous sensory zone of the radial nerve and is highlighted in red.
- Palmar aspect: the radial border of the thumb
Proximal lesion: complete loss of motor and sensory function
Distal lesion (radial tunnel syndrome): partial loss of motor function; preservation of sensory function

© AMBOSS

**Ulnar nerve neuropathy**
Motor deficits:
- Claw hand: The 4^th and 5^th joints are hyperextended at the MCP and flexed at the IP joints at rest (neutral position).
- Froment sign: The patient is asked to grasp a piece of paper between the thumb and the index finger. When the examiner tries to pull the paper away, the thumb flexes at the IP joint because the flexor pollicis longus (supplied by the median nerve) compensates for the paralyzed adductor pollicis (supplied by the ulnar nerve).
Also depicted here is hollowing of the intermetacarpal spaces and the 1^st web space due to the atrophy of the interossei, which is seen in chronic ulnar nerve palsy.
Sensory deficits:
- Dorsal aspect: ulnar 2½ fingers (less commonly, 1½ fingers), excluding the tips of the 3^rd and 4^th fingers
- Palmar aspect: ulnar 1½ fingers
Proximal lesion: complete loss of motor and sensory functions
Distal lesion: complete loss of motor function; preservation of sensory function

© AMBOSS

**Humeral unicameral bone cyst (UBC) with pathological fracture**
X-ray right humerus (AP view) of an adolescent patient with pain
An expansile lucent lesion in the humeral diaphysis (green overlay) has a geographic margin with a narrow zone of transition. The appearance is compatible with a unicameral bone cyst (simple bone cyst). A pathological fracture (red overlay) has occurred through the distal aspect of the cyst.
Unicameral bone cysts are common benign lucent bone lesions. They are typically discovered in childhood or adolescence either incidentally or in the course of diagnosing a pathological fracture.

Source: © IMPP

**Distal humerus fracture**
X-ray elbow (AP view)
A comminuted fracture of the distal humerus (H, green overlay) is accompanied by displacement and overriding of the main fragments, resulting in foreshortening of the humerus.
U: Ulna, R: Radius

Source: © IMPP

**Anterior and posterior fat pad sign**
X-ray of the elbow joint, lateral view
13-year-old girl who fell on an outstretched hand. The bones show no fracture, but a fat pad sign can be seen ventral and dorsal to the humeral shaft. The fat pad sign indicates elbow joint effusion. It arises when the fatty tissue usually attached to the distal humerus is lifted off the bone because of the joint effusion; while the fatty tissue is usually visible as a lucency parallel to the humerus, it becomes crescent-shaped if there is an effusion.

Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.

**Anterior and posterior fat pad signs in supracondylar humerus fracture**
The top row shows lateral views of a normal elbow joint. The anterior fat pad (highlighted in yellow on the right radiograph) resides in the coronoid fossa and is normally visible. It is labeled on the illustration and seen on the left radiograph as a lucent stripe ventral to the distal humerus. The posterior fat pad resides in the olecranon fossa and is not normally visible.
The bottom row shows the result of a supracondylar fracture (not visible). Hemarthrosis has elevated the anterior and posterior fat pads. The posterior fat pad is now visible (posterior fat pad sign) and the anterior fat pad has the appearance of a spinnaker sail (anterior fat pad sign or sail sign).
The anterior and posterior fat pad signs are valuable in diagnosing fractures of the elbow, particularly in cases where a fracture line may not be visible (e.g., supracondylar humeral fracture, radial head fracture)

© AMBOSS

Differential diagnoses

Differential diagnosis of proximal humerus fractures [2]

Shoulder dislocation
Acromioclavicular joint separation
Clavicle fracture
Scapula fracture
Rotator cuff injury
Soft tissue injury

Differential diagnosis of distal humerus fractures [2]

Olecranon fracture
Radial head fracture
Elbow dislocation
Radial head subluxation
Soft tissue injury

The differential diagnoses listed here are not exhaustive.

Treatment

Initial management by fracture type [2]

All patients: Initiate general fracture care, including analgesia.
Proximal humerus fractures
- Immobilize in an arm sling.
- Consult orthopedics urgently for:
  - Displaced fracture segments
  - Fracture-dislocation
Humeral shaft fractures
- Immobilize in a coaptation splint.
- Consult orthopedics urgently for:
  - Radial nerve injury
  - Severely displaced fractures
  - Comminuted fractures
Distal humerus fractures
- Immobilize in a long arm posterior splint.
- Consult orthopedics urgently for:
  - Displaced supra- or epicondylar fractures
  - All transcondylar, intercondylar, and condylar fractures
  - Presence of intraarticular fragments

Nonoperative management

Nonoperative management is generally possible for nondisplaced, closed fractures.
Devices include hanging-arm casts, coaptation splints, and arm slings
See also: “Conservative treatment of fractures”

Surgical treatment

Fractures that commonly require surgical treatment include:
- Open fractures
- Poor reduction of displaced fractures
- Neurovascular injury
- Pathologic fractures
- Simultaneous humerus and forearm fractures (floating elbow)
Operative techniques depend on
fracture location and type and include:
- Open reduction and internal fixation (ORIF)
- Closed reduction and internal fixation (CRIF)
- Intramedullary nailing (IMN)
- Arthroplasty

$Humeral shaft fracture after intramedullary nail fixation$

Complications

Proximal humerus fracture
- Avascular necrosis of humeral head (axillary artery injury)
- Adhesive capsulitis
- Heterotopic bone formation
Distal humerus fracture
- Brachial artery injury (common)
  
  Absent or diminished radial pulse suggests brachial artery entrapment (especially following reduction) and compartment syndrome.
  
  May lead to Volkmann ischemic contracture (late complication)
- Malunion and varus deformity of the elbow

Humerus fracture nerve palsies
Nerve	Motor function	Sensory function	Associated site of humerus fracture
Axillary	Flat deltoid ↓ Arm abduction at shoulder > 15 degrees	↓ Sensation over deltoid and lateral arm	Proximal humerus
Radial	Wrist drop ↓ Grip strength	↓ Sensation over dorsal hand and posterior arm	Humeral shaft Distal humerus
Ulnar	Claw hand deformity Froment sign Radial deviation when wrist is flexed	↓ Sensation over medial 1 ½ fingers (5^th digit and half of the 4^th digit) including hypothenar eminence	Distal humerus
Median	Anterior interosseous nerve syndrome: unable to oppose index finger and thumb of affected hand ↓ Wrist flexion ↓ Flexion of lateral fingers and ↓ thumb opposition	↓ Sensation over thenar eminence and over lateral 3½ fingers (first 3½ digits, beginning with the thumb)	Distal humerus

See “Peripheral nerve injuries in the upper extremity“ and “Complications of fractures.”

“Broken ARM:“ Axillary, Radial, and Median nerves can be injured.

Injuries to the median nerve and brachial artery, which both cross the elbow, are common complications of supracondylar fractures.

$Anatomical structures at risk in humerus fractures$ Volkmann ischemic contracture

We list the most important complications. The selection is not exhaustive.

**Anatomical structures at risk in humerus fractures**
Depending on the location of humerus fractures, different anatomical structures are at risk.
Illustration indicates structures at lower risk of injury in parentheses.

© AMBOSS

References

Walls R, Hockberger R, Gausche-Hill M, Erickson TB, Wilcox SR. "Rosen's Emergency Medicine 10th edition- Concepts and Clinical Practice E-Book". Elsevier Health Sciences. (2022). ISBN: 9780323757904
Carofino BC, Leopold SS. "Classifications in brief: the Neer classification for proximal humerus fractures.". Clin Orthop Relat Res. 471(1). :39-43. (2013)
Emery KH, Zingula SN, Anton CG, Salisbury SR, Tamai J. "Pediatric elbow fractures: a new angle on an old topic". Pediatr Radiol. 46(1). :61-66. (2015)
Pencle FJ, Varacallo M. "Proximal Humerus Fracture". StatPearls. (2020)