Humeral Shaft Fractures - Trauma (2024)

• Humeral shaft fractures are common fractures of the diaphysis of the humerus, which may be associated with radial nerve injury.

• Diagnosis is made with orthogonal radiographs of the humerus.

• Treatment can be nonoperative or operative depending on location of fracture, fracture morphology, and association with other ipsilateral injuries.

Epidemiology

• Incidence

  • 3-5% of all fractures

  • 7 to 11.3 per 100,000

• Demographics

  • age

    • 60% occur in patients olderthan 50 years

    • bimodal age distribution

      • young

        • high-energy trauma

        • peak incidence in third decade of life

    • elderly patients

      • low energy falls

      • osteopenic patients

  • sex

    • 70% occur in men when ageless than 50

    • 70% occur in women when agegreater than 50
      

  • Location

    • 30% occur in the proximalthird of the humeral shaft

    • 60% occur in the middlethird of the humeral shaft

      • Most common location

    • 10% occur in the distalthird of the humeral shaft

  • Risk factors

    • previous fracturehistory

    • smoking in men

    • elderly age

    • osteoporosis

• Pathophysiology

  • mechanism of injury

    • ground level fall (60%)

      • most common mechanism

    • motor vehicle accident (~30%)

      • 2nd most common mechanism

    • pathologic fractures (4.3%)

    • open fractures (3%)

  • proximalthird humeral shaft fractures

    • commonin older individuals

    • oftenresults from fall onto an outstretched hand resulting in impaction fracture atthe surgical neck

  • middlethird humeral shaft fractures

    • transversefracture

      • resultof a direct blow to the arm

    • spiralfracture

      • resultsfrom a fall onto an outstretched hand or from torsional force

  • distalthird humeral shaft fractures

    • resultfrom fall onto a flexed elbow

• Associatedconditions

  • floating elbow

    • fracture of the humeral shaft and the proximal to middle radius and ulna

    • often occurs as a result of a high-energy trauma

    • morecommon in pediatric patients than in adults

  • ipsilateralshoulder dislocation
    

    • uncommoninjury pattern
      

    • dislocationis most likely to be a posterior dislocation rather than an anteriordislocation
      

• Osteology

  • humeral shaft extends fromthe surgical neck of the humerus to the supracondylar ridge and is cylindricalin shape

  • distally humerus becomestriangular with the formation of the medial and lateral supracondylar ridges

  • intramedullary canalterminates 2 to 3 cm proximal to the olecranon fossa

  • radial groove is adepression along the posterolateral aspect of the humerus where the radialnerve and profunda brachii artery traverse

• Arthrology

  • articulates with scapulaproximally and distally with the radius and ulna

• Muscles

  • insertion for

    • pectoralis major

    • deltoid

      • will abduct proximal fragment in fracturesoccurring proximal to the insertion of the pectoralis major

    • coracobrachialis

  • origin for

    • brachialis

    • triceps

    • brachioradialis

• Nerve

  • radial nerve

    • exits axilla posterior tothe brachial artery

    • enters the posteriorcompartment of the arm through the triangular interval

    • runs between the medial andlong head of the triceps

    • radial nerve is found medial to the long and lateral heads and 2cm proximal to the deep head of the triceps

    • courses along the spiral groovethen become anterior to the humerus

      • ~7.5cm from the articularsurface

    • radial nerve exits the posterior compartment through the lateral intramuscular septum 10 cm proximal to radiocapitellar joint

      • 20cm proximal to the medial epicondyle

      • 14cm proximal to the lateral epicondyle

  • ulnar nerve

    • Enters the posterior compartmentat the arcade of Struthers and runs medially towards cubital tunnel

    • ~8cmfrom the medial epicondyle

  • axillary nerve

    • runs posterior to anterior around the proximal humerus 4 to 7cm from the tipof the acromion

• Compartments

  • anterior compartment

    • muscles

      • biceps brachii, brachialis, and coracobrachialis

    • vasculature

      • brachial artery and vein

    • nerves

      • musculocutaneous, median, and ulnar nerve

  • posterior compartment

    • muscles

      • triceps

      See Also

      The 3 Ways You Can Break Your HumerusProximal Humerus Fractures - TraumaHumerus Fracture: Types, Symptoms & TreatmentHumerus Fractures Overview

    • nerves

      • radial nerve

• OTA

  • bone number: 1

  • fracture location: 2

  • fracture pattern: simple:A, wedge:B, complex:C

• Garnavos classification

  • location

    • P: proximal

    • M: middle

    • D: distal

    • j: extension into the joint

  • morphology

    • S: simple

      • T: transverse or oblique

      • S: spiral

    • I: intermediate

      • one or two sizable butterfly fragments

    • C: complex

      • three or more butterfly fragments, or significant comminution

• Descriptive

  • fracture location: proximal, middle or distal third

  • fracture pattern: spiral, transverse, comminuted

• Holstein-Lewis fracture

  • a spiral fracture of the distal one-third of the humeral shaft commonly associated with neuropraxia of the radial nerve (7-22% incidence)

    • increases risk of radialnerve entrapment with the fracture

• Symptoms

  • pain

  • extremity weakness

• Physical exam

  • swelling

  • tenderness over the fracture site

  • skin tenting

  • examinination of overall limb alignment for deformity

    • will often present with shortening and in varus

  • preoperative or pre-reduction neurovascular exam is critical

    • examine and document status of radial nerve pre and post-reduction

      • wrist and thumb interphalangeal joint extension

      • sensation over the dorsum of the hand

• Radiographs

  • views

    • AP and lateral

      • be sure to include joint above and below the site of injury

    • transthoracic lateral

      • may give better appreciation of sagittal plane deformity

      • rotating the patient prevents rotation of the distal fragment avoiding further nerve or soft tissue injury

    • traction views

      • may be necessary for fractures with significant shortening, proximal or distal extension but not routinely indicated

• CT scan

  • may be utilized if there is concern for intra-articular extension

• CTA

  • may be indicated if there is concern for vascular injury

• Electromyography (EMG)

  • indicated in the setting of nerve palsy to assess for nerve recovery,but is not indicated acutely as it will not dictate fracture management

• Nonoperative

  • immobilization (coaptation splintor hanging arm cast for 7 to 10 daysfollowed by a functional brace)

    • indications

      • indicated in vast majority of humeral shaft fractures

        • criteria for acceptable alignment include:

          • < 20° anterior angulation

          • < 30° varus/valgus angulation

          • < 30° of rotational malalignment

          • < 3 cm shortening

      • relative indications

        • community ambulator

        • noncompliant patients

    • contraindications

      • absolute

        • severe soft tissue injury or bone loss

        • vascular injury requiring repair

        • brachial plexus injury

      • relative

        • see relative operative indications section

        • worsening nerve dysfunction

        • radial nerve palsy is NOT a contraindication to functional bracing

    • outcomes

      • averageunion rate of 93.5% (77-100%)

        • increased risk withproximal third (54%), and oblique or spiral fracturepatterns (23%)

      • average time to union of 10.7 weeks (6.5-22 weeks)

      • average malunion rate of 12%

      • range of motion

        • 38-45% of patients lose externalrange of motion (5-45 degrees)

        • 88.6% of patients lose lessthan 10 degrees of shoulder motion

        • 92% lose less than 10degrees of elbow motion

      • varus angulation is common but rarely has functional or cosmetic sequelae

  • damage control orthopaedics (DCO)

    • closed humerus fractures, including low velocity GSW, should be initially managed with a splint or sling

    • type of fixation after trauma should be directed by acceptable fracture alignment parameters, fracture pattern and associated injuries

• Operative

  • external fixation (Exfix)

    • indications

      • high energy complex or comminuted fracture

      • open fracture

      • significant soft tissue or bony defect

      • floating elbow

      • hemodynamically unstable polytrauma

      • concomitant vascular injury

    • typically utilized asprovisional fixation until definitive treatment can be performed, but may beused definitely if needed

    • outcomes

      • average operative time of30 minutes (18 to 50 minutes)

      • 80% achieve good to excellentoutcomes

      • superficial pin track infectionrate of 12%

  • open reduction and internal fixation (ORIF) and minimally invasive plate osteosynthesis
    

    • indications

      • absolute

        • open fracture

        • vascular injury requiring repair

        • brachial plexus injury

        • ipsilateral forearm fracture (floating elbow)

        • compartment syndrome

        • periprosthetic humeral shaft fractures at the tip of the stem

        • inability to maintain satisfactory reduction closed

        • progressive nerve deficit after closed manipulation

      • relative

        • bilateral humerus fracture

        • polytrauma or associated lower extremity fracture

          • allows early weight bearing through humerus

        • pathologic fractures

          • typically indicated if life expectancy is greater than 6 months

        • burns or soft tissue injury that precludes bracing

        • fracture characteristics

          • distraction at fracture site

          • segmental fractures

          • short oblique or transverse fracture pattern

            • OTA type A

          • intraarticular extension

          • long oblique proximal humeral shaft fracture

        • large body habitus, obesity, or large breasts

        • radial nerve palsy

      • outcomes

        • significantly lower rates of nonunion and malunion versus nonoperativemanagement

          • average malunion rate of 1%

          • average union rate of 90-92%

        • average time to union of 11.9 weeks

        • improved DASH scores at 6 weeks and 3 months with no significantdifference at 12 months compared to nonoperative management

          See Also

          Humerus Fracture: Causes, Symptoms & Treatment

  • intramedullary nailing (IMN)

    • indications

      • relative

        • pathologic fractures

        • segmental fractures

        • severe osteoporotic bone

        • overlying skin compromise limits open approach

        • polytrauma

    • outcomes

      • lower risk of infection(1.2%) than ORIF (5.4%)

      • no significant risk ofreoperation (average 11.6%) versus ORIF (average 7.6%)

      • no difference in rates ofnonunion with faster time to union (average 10 weeks) than ORIF (average 11.9weeks)

      • significantly fasteroperative time (average 61 minutes) than ORIF (average 88 minutes)

      • increased rate whencompared to plating (16-37%)
        

        • greater risk of shoulderimpingement postoperatively

        • functional shoulder outcomescores (ASES scores) not shown to be different between IMN and ORIF

• Coaptation Splint & Functional Bracing

  • coaptation splint or hanging arm cast

    • applied until swelling resolves

    • adequately applied splint will extend up to axilla and over shoulder

    • common deformities include varus and extension

      • valgus mold to counter varus displacement

  • functional bracing

    • extends from 2.5 cm distal to axilla to 2.5 cm proximal to humeral condyles

    • sling should not be used to allow for gravity-assisted fracture reduction

    • shoulder extension used for more proximal fractures

    • weekly radiographs for first 3 weeks to ensure maintenance of reduction

      • every 3-4 weeks after that

• External Fixation

  • approaches

    • proximal pins

      • anterolateral surface of proximal humerus

      • mini-open approach with dissection down to bone to mitigate axillary nerve injury

    • distal pins

      • lateral aspect of distal fragment

      • requires mini-open approach with dissection down to bone to mitigate radial nerve injury

      • most distal pin is just proximal to olecranon fossa

      • visualize cortical surface prior to inserting pins

• Open Reduction and Internal Fixation (ORIF)

  • approaches

    • anterior (brachialis split) approach to humerus

      • used for middle third shaft fractures

      • deep dissection through internervous plane of brachialis muscle

        • lateral fibers (radial n.) and medial fibers (musculocutaneous n.) in majority of patients (~80%)

    • anterolateral approach to humerus

      • used for proximal third to middle third shaft fractures

      • distal extension of the deltopectoral approach

      • performed in a supine orbeach chair position with arm abducted 45° to 60°

      • radial nerve identified between the brachialis and brachioradialis distally

        • protected proximally anddistally by the brachialis

        • brachioradialis willprotect the musculocutaneous nerve distally

      • cephalic vein and anterior humeral circumflex arteries may be encountered during the surgical approach

    • posterior approach to humerus

      • maybe performed eitherprone or in a lateral position

      • usedfor distal to middle third shaft fractures

        • can be extensile

        • allows for exposure from the olecranon fossa to the junction of the proximal and middle third of the humerus

      • triceps may either be split or elevated with a lateral paratricipital exposure

        • triceps split

          • incision through the commontendon of the triceps

          • allows for retraction ofthe lateral head of the triceps laterally and long head of the triceps medially

          • allows exposure to theradial nerve and profunda brachii artery within the spiral groove

            • lateral brachialcutaneous/posterior antebrachial cutaneous nerve serves as an anatomic landmarkleading to the radial nerve

          • benefits

            • avoids the need for ulnar nervedissection and mobilization

            • can allow for adequate exposureof the humeral shaft fracture

          • limitations

            • 55% of the humeral shaftcan be exposed without radial nerve mobilization

            • 76% of the humeral shaftcan be exposed with radial nerve mobilization

            • does not utilize a trueinter-nervous plane

            • limited proximal extensionof the incision

        • triceps sparing or “paratricipital”

          • utilizes lateral and medial windows without disrupting the extensormechanism
            

          • lateral brachial cutaneous/posterior antebrachial cutaneous nerve serves as an anatomic landmark leading to the radial nerve during a paratricipital approach

          • lateral window

            • lateral head of the tricep and intermuscular septum

            • allows for identification of the radial nerve, and posteriorantebrachial cutaneous nerve

          • medial window

            • mobilization of the ulnar nerve followed by dissection to the medialintermuscular septum border posteriorly

          • benefits

            • minimizes injury to the triceps

            • improved postoperative functional measures

            • decreased risk of denervation of the triceps and anconeus

            • allows for exposure of ~94% of the humeral shaft through the lateralwindow

          • limitations

            • requires dissection and mobilization of the ulnar nerve for the medialwindow

        • lateral approach

          • extends from the insertion of the deltoid to the lateral epicondyle

          • allows for exposure of the distal two-thirds of the humerus

          • the interval is between the lateral intermuscular septum and the triceps

          • radial nerve identified proximal to the deep head of the triceps andmobilized by releasing the lateral intermuscular septum

          • higher risk of iatrogenic radial nerve injury

        • medial approach

          • primarily used to access the brachial artery, median nerve, and ulnarnerve

          • rarely used for fracture fixation

          • incision extends from the proximal medial margin of the biceps distally tothe medial epicondyle

            • ulnar nerve is retracted posteromedially

            • median nerve and brachial artery retracted anterolaterally

        • minimally invasive plate osteosynthesis

          • proximal and distal incisions performed through an anterolateralapproach followed by the creation of an extraperiosteal tunnel

          • theplate is tunneled and positioned under fluoroscopic guidance

          • Minimizes surgical dissection, but increases the risk of radial nerve injurydue to lack of direct visualization

  • techniques

    • plate osteosynthesiscommonly with narrow or broad, 3.5mm or 4.5mm dynamic compression plate orlimited contact dynamic compression plate

      • dynamic compression plateallows for staggered screws

      • narrow dynamic compressionplate better accommodates patients with a more narrow humerus

      • limited contact dynamiccompression plate provide benefit of being easier to contour, decreased stressshielding, and preservation of periosteal blood supply

    • relationship of plate and radial nerve must be respected to preventinadvertent nerve injury

    • absolute stability with lag screw or compression plating in simple patterns

    • apply plate in bridging mode in the presence of significant comminution

    • may require the incorporation of condyles or dual plating in distalfractures

    • bony defects up to 3cm can be dealt with via shortening, but larger defects(>3cm) may require grafting

  • postoperative

    • full crutch weight bearing shown to have no effect on union

• Intramedullary Nailing (IMN)

  • techniques

    • can be done antegrade or retrograde

      • antegrade

        • performed supine

        • 3cm incision over theanterolateral edge of the acromion down the deltoid, which is then split toidentify the rotator cuff

        • entry site for the nailthrough the supraspinatus fibers as medial as possible to apex of the humeralhead

      • retrograde

        • performed prone or lateral through a posteriorincision over the posterior supracondylar cortex

      • avoid reaming across thefracture site to prevent radial nerve injury

  • complication

    • nonunion

      • nonunion rates not shown to be different between IMN and plating in recent meta-analyses

      • IM nailing associated with higher total complication rates

    • nerve injury

      • radial nerve

        • at risk with a lateral to medial distal locking screw

          • while controversial, a recent meta-analysis showed no difference between the incidence of radial nerve palsy between IMN and plating

      • musculocutaneous nerve

        • at risk with an anterior-posterior locking screw

      • axillary nerve

        • at risk with proximal locking screws in antegrade nails

        • anterior and posterior humeral circumflex vessels are also at risk

    • shoulder pain

      • increased rate when compared to plating (16-37%)

      • functional shoulder outcome scores (ASES scores) not shown to be different between IMN and ORIF

      • supraspinatus at risk with antegrade nails

        • due to the avascular nature of the supraspinatus tendon atit* insertion site near the greater tuberosity

          • entry portal should be created near the musculotendinous junction

        • entry portal should not be greater than 1cm

  • postoperative

    • full weight bearing allowed and had no effect on union

• Nonunion

  • no callous on radiograph and gross motion at the fracture site at 6 weeks from injury has a 90-100% PPV of going on to nonunion in closed humeral shaft fractures

    • 82% sensitivity and 99% specificity

  • radiographic union score for humeral fracture (RUSHU)

    • 1 score per cortex on radiographs obtained 6-weeks from injury

      • 1: absent callus

      • 2: present, nonbridging callus

      • 3: present, bridging callus

    • score ≥8 - 86% NPV for nonunion

    • score <8 - 65% PPV

  • risk factors

    • humeral shaft fractures treated nonoperatively dependent on fracture pattern

      • OTA type A (15.4 to 29%) > type B (4%) >type C (0%) fractures

  • No significant difference in the rate of nonunion following open reductionwith internal fixation versus intramedullary nailing

  • treatment

    • higher rates of union with plate fixation and autologous bone grafting than with exchange intramedullary nailing

    • management predicated by type of nonunion (atrophic, hypertrophic, infected)

      • atrophic nonunion

        • debridement and curretage of non-viable fragment and fibrous scar at fracture site

        • intramedullary nail revision with reaming and exchange to larger nail

          • ream up by at least 1mm to improve biomechanical stability

        • compression plating with bone grafting

          • iliac crest graft, femoral autograft from REA (reamer/irrigator/aspirator)

          • bone graft subsititue

      • hypertrophic nonunion

        • intramedullary nailing with exchange for larger nail

        • locked angle plating

• Malunion

  • varus angulation is common but rarely has functional or cosmetic sequelae

  • risk factors

    • transverse fracture patterns

• Radial nerve palsy

  • incidence

    • overall incidence of 12.3% ( 8-15%)

    • increased incidence distal one-third fractures (22%)

    • neuropraxia most common injury in closed fractures and neurotomesis in open fractures

    • iatrogenic radial nerve palsy is most common following ORIF via a lateral approach (20%) or posterior approach (11%)

    • spontaneous recovery found at an average of 7 weeks, with full recovery at an average of 6 months

  • risk factors

    • fracture location

      • distal third (56.9%) > middle third (41.5%) > proximal third (1.5%)

    • fracture type

      • transverse (21.2%) > spiral (19.8%) > oblique (8.4%) > comminuted (6.8%)

    • open fracture

  • treatment

    • observation

      • indicated as initial treatment in closed humerus fractures

      • approximately 77.2% with spontaneous radial nerve recovery

        • 85-90% of these will recovery within the first 3 months

      • obtain NCS/EMG at ~2 months

        • useful to determine the extent of nerve damage, baseline of function, and to monitor recovery

      • wrist extension in radial deviation is expected to be regained first

      • brachioradialis first to recover, extensor indicis is the last

    • surgical exploration

      • indications

        • open fracture with radial nerve palsy (likely neurotomesis injury to the radial nerve)

        • closed fracture that fails to improve over ~4-6 months

        • fibrillations (denervation) seen on EMG

      • may require debridement or removal or incarcerated fragments, nerve grafting, or nerve transfers at the time of exploration

      • outcomes

        • radial nerve appearance at the time of exploration

          • nerve in continuity (62.7%)

          • lacerated (26.8%)

          • incarcerated within the fracture site (10.5%)

        • timing of exploration

          • early exploration (within three weeks of injury)

            • recovery rate ~90%

          • late exploration (eight weeks or more out from injury)

            • recovery rate ~68%

    • tendon transfers

      • indications

        • persistent radial nerve palsy - optimal timing debated

        • wrist extension: PT to ECRB

        • finger extension: FCR/FCU to EDC

        • thumb extension: PL to EPL

  • outcomes

    • overall recovery rate of 88.6%

      • primary nerve palsy recovery rate - 88.2%

      • iatrogenic/secondary nerve palsy recovery rate - 93.9%

    • predictable recovery pattern

      • brachioradialisand extensor carpi radialis longus are first to recover

      • extensorpollicus longus and extensor indicis proprus are last to recover