Humerus Shaft Fractures: Clinical Features, Classification, Treatment and Complications

Humeral shaft fractures are common fractures affecting the diaphysis of the humerus bone, and they might be associated with radial nerve injury

Humeral shaft fractures have a bimodal distribution in older women (due to low energy falls), and young men (as a result of high energy injuries)

They are mostly treated non operatively and they heal in around 9 weeks

Mechanism of Injury

• These fractures are caused by low energy trauma (most commonly) due to A fall on the hand or elbow or a direct blow to the arm
• They also could be caused by a high energy trauma such as in road traffic accident or crush injuries
• Or the mechanism could be due to a pathology causing the Fracture (e.g. metastasis of the humeral shaft)

Classification

Humeral shaft fractures are classified according to the AO classification of diaphyseal fractures into:

• A: simple, two fragment fractures
• B: wedge fractures, (butterfly)
• C: Complex fractures

A: Simple, two fragment fractures

B: Wedge fractures, (butterfly): in these fractures, there is some contact between the two main fragments

C: Complex fractures: in these fractures there is no contact between the two main fragments

Holstein-Lewis Fracture

• Oblique fracture at the junction of middle and distal thirds of the humerus
• This fracture is commonly associated with radial nerve injury in 22% of cases

Holstein-Lewis humeral shaft fracture; by Adam of spiralhumerusfracture.blogspot.com/, Public domain, via Wikimedia Commons

Pathological Anatomy

• If the fracture is above the deltoid insertion, the proximal fragment is adducted by pectoralis muscle in most of the cases
• If below deltoid insertion, then the proximal fragment is abducted by the deltoid in most of the cases
• Shortening type of displacement occurs in these fractures due to muscle pull on the distal fragment

Clinical Features

• Patient with humerus shaft fracture present supporting their injured arm with the other one and complaining of pain
• There maybe swelling and some shortening of the arm, bruising may not be seen in presentation but will develop after
• During reduction, crepitus maybe heard
• Test for radial nerve function before and after treatment by assessing active extension of the metacarpophalangeal joints

Imaging

X-Rays

• AP and lateral humerus X ray radiographs are enough to make the diagnosis and they will show the Fracture line and any displacement is seen well

Humerus shaft fracture; by Hellerhoff, CC BY-SA 4.0, via Wikimedia Commons

Humerus shaft fracture; by Hellerhoff, CC BY-SA 4.0, via Wikimedia Commons

Treatment

• Non Operative
• Operative

Non Operative Treatment

• 90% of the humerus shaft fractures treated non operatively and heal in around 9 weeks
• Fractures of the humeral shaft don’t need perfect reduction nor perfect immobilization, the weight of the arm is enough to pull the fragments into alignment
• Non operative treatment is done through a coaptation splint for 9 days and then replaced with a functional (Sarmiento) brace after
• A coaptation splint is done initially in the emergency department and it is used to stabilize the fracture for the first 9 days
• Then the coaptation splint is replaced with a Functional (Sarmiento) brace
• Previously a Hanging cast was used but nowadays, its use is diminished due to it being heavy and can’t be adjusted when swelling subsides unlike the functional brace
• The wrist and fingers are exercised from the start
• Pendulum exercises of the shoulder are begun within a week, but active abduction is avoided until the fracture is united (around 9 weeks)

Operative Treatment

• The great majority of humerus shaft fractures unite with non operative treatment and there is no good evidence that the union rate is higher with operative treatment due to distraction that comes with nailing or the periosteal stripping that comes with plating …
• The complication rate after operative treatment of the humerus is high
• But there is clear indications for surgery

indications of operative treatment

• Severe displacement, if more than 30 degrees of angulation or more than 3 cm of shortening or more than 15 degrees of rotation
• Dysvascular limb or expanding hematoma
• Open fractures
• Segmental or intraarticular fracture
• Multiple trauma
• Floating elbow (humeral fractures + forearm fractures)
• Pathological fracture
• Non union
• Patient choice: patient feel fracture fragment moving in the splint which is distressing => they choose to do surgery

• Operative treatment is achieved either by ORIF with compression plate and screws (most common) or interlocking intramedullary nail
• External fixation

Complications

• Humerus shaft fractures are associated with many complications, those include:

Brachial artery injury

• Early complication
• Brachial artery might be damaged, most commonly there will be an expanding hematoma and rarely there will be signs of vascular insufficiency to the limb due to rich collateral circulation
• This complication is an emergency requiring exploration and direct repair or grafting

Radial nerve palsy

• Early complication, occur in 10% of cases
• Radial nerve palsy manifest as wrist drop and paralysis of the metacarpophalangeal extensors, this complication occur more with oblique fractures at the junction of middle and distal thirds (Holstein Lewis fracture)
• In closed injuries the radial nerve mostly sustain neuropraxia type of injury and will recover afterwards (not indication for surgery)

Nerve injury

• But If radial nerve function was intact before manipulation but got defective afterwards, or after surgery this means that the nerve was torn during that and surgical exploration is necessary
• The wrist and hand must be regularly exercised passively to preserve joint function until the nerve recovers
• If not recovered by 12 weeks then surgical exploration should be done

Compartment syndrome

• Early complication
• Compartment syndrome is muscle swelling within a fascial compartment in the arm due to damage to these muscles caused by the trauma
• It is caused by a tight cast applied in emergency department, and requires emergency fasciotomy surgery

Delayed union

• Transverse fractures sometimes take months to unite
• As long as there is callus formation, it is worth waiting, meanwhile shoulder exercises should be done to prevent stiffness

Non union

• Rate of non union in low energy humeral shaft fractures treated non operatively is less than 3% while high energy segmental fractures and open fractures are more prone to non union
• Rate of non union in intramedullary nailing is around 10%
• If elbow or shoulder movement is forced before consolidation of the fracture or if the intramedullary nail is removed too early, this may lead to refracturing and then non union is more likely
• Treatment of non union is operative, bone ends are freshened, and cancellous bone graft is packed around them and the reduction is held with an intramedullary nail or a compression plate

Joint stiffness

• Common complication
• Can be minimized by early activity

Course Menu

This article is a part of the Shoulder and Arm Trauma Free Course, this course also contains:

• Course Introduction
• Clavicle Bone Fractures
• Scapula Bone Fractures
• Acromioclavicular Joint Injuries
• Sternoclavicular Joint Injuries
• Anterior Shoulder Dislocation
• Posterior Shoulder Dislocation
• Inferior Shoulder Dislocation
• Proximal Humerus Fractures
• Humeral Shaft fractures
• Shoulder X-ray Interpretation