Elbow and forearm injuries

Anatomy

• Radial nerve
  • Proximal portion provides motor innervation to wrist extensors
  • Deep branch (posterior interosseous nerve) provides innervation to finger extensors
  • Superficial branch purely sensory over dorsal aspect of hand (radial aspect)
• Median nerve
  • Proximal portion innervates wrist flexors and FDS
  • Anterior interosseous nerve branch provides motor innervation to remaining deep finger flexors
  • Remaining portion provides sensation to palm + dorsal tips of fingers and recurrent branch of median nerve to thenar muscles

imaging

• Radiocapitellar line – through middle
• Anterior humeral line – through posterior 2/3 of capitellum
• Posterior fat pad always pathological
• Anterior fat pad may be small but large = pathology

Biceps tendon rupture

• Vast majority proximal long head (coracoid)
• Typically repetitive microtrauma, overuse +- steroid use
• Get X-ray as avulsion fractures do occur
• Proximal rupture Rx
  • Sling, ice, analgesics and referral to ortho for definitive care
  • Surgical repair for young, active patients
  • Conservative approach with immobilisation for older patients as ADL’s will not be significantly effected by injury

Biceps tendon rupture

• Distal biceps injury
  • Strength loss, especially supination, is greater for distal tears
  • Biceps squeeze test can detect rupture (60-80 degrees flexion, squeeze biceps belly and should supinate)
  • Hook test – hook finger behind biceps tendon in 90 degrees flexion (cannot do if ruptured)
  • Check X-ray for avulsions
  • ED treatment – Sling, ice, analgesics, referral to ortho
  • Supination strength reduced by 50% and flexion by 30% without surgical repair

Triceps tendon rupture

• Rare and almost always distal
• If complete rupture, ability to extend elbow is lost
• Can perform modified Thompson test
• X-ray as olecranon avulsion is common
• ED treatment – Sling, ice, analgesics, referral to ortho
• Complete tears require surgical repair while partial tears can be treated with immobilisation

Lateral epicondylitis

• Tennis elbow from wrist and digit extensors and foreaem supinators
• Tenderness over lateral epicondyle and pain with resisted wrist and digit extension + forearm supination
• Rest, ice, NSAID’s, immobilisation
• Physio forearm stretching and strengthening are effective
• Steroid injections provide short-term relief but increase 1 year recurrence rates
• Surgery for refractory cases

Medial epicondylitis

• Less common Golfer’s elbow
• Tenderness and pain with resisted forearm pronation, wrist and digital flexion
• May develop ulnar neuropathy also due to proximity
• Treatment is the same

Elbow dislocation

• Third most common large joint dislocation
• Terrible triad = Elbow dislocation, radial head and coronoid fracture
• 5 types of dislocation
  • Posterior
  • Anterior
  • Medial
  • Lateral
  • Divergent
• 90% are posterolateral

Elbow dislocation

• First priority is assessment of neurovascular status: Brachial artery, ulnar/radial/median nerves
  • Neurovascular complications occur in 8-21% of patients (mostly ulnar nerve)
  • Vascular complications in 5-13% 
    • Absence of radial pulse before reduction, open dislocation and systemic injuries suggest arterial injury – angiography required if suspicion exists
• Associated fractures
  • Children: Medial epicondyle
  • Adults: Radial head or coronoid process typically

Elbow dislocation

• Closed reduction
  • Two-person technique:
    • Supine, gentle longitudinal traction on wrist and forearm with one hand while assistant countertractions upper arm
    • Correct any medial or lateral displacement with other hand and then apply downward pressure on the proximal forearm to disengage the coronoid process from the olecranon fossa
    • Continue distal traction and then flex the elbow
  • Second two-person technique
    • Prone with arm abducted and elbow slightly flexed
    • Assistant applies longitudinal traction on wrist and forearm, grasp elbow with both thumbs on olecranon and apply firm pressure to push olecranon up and over trochlea

Elbow dislocation

• Post-reduction check ROM as if not stable or limited ROM suggests intra-articular fragment and necessitates surgical repair
• Then assess medial and lateral collaterals in full extension
  • Medial instability (from ulnar collateral injury) that cannot be stabilised by 90 degree flexion and pronation requires orthopaedic consult. If able to be stabilised by this manoeuvre, splint in this position and arrange follow-up
• After reduction, immobilise stable dislocations in a long arm posterior splint with elbow in just less than 90 degrees flexion and slight pronation
• Need follow-up next day for neurovascular function
• Early ROM after 1 week of splinting leads to favourable outcomes
• Ortho consult for open, irreducible, neurovascular issues, instability as described above, itnra-articular fragments and associated fractures.

Fractures about the elbow

• Supracondylar fractures
  • Most common fracture about the elbow in children 5-10yo but can also occur in adults
  • Extension-type (>95%)
    • Displaced posteriorly
    • FOOSH with elbow in full extension
    • Non-displaced fractures may only show fat pad signs or anterior humeral line through anterior 1/3 of capitulum
    • Long-arm flexion cast in neutral position
    • If >20 degrees angulation, needs ortho opinion and possible fixation
    • Open reduction required for vascular compromise (likely entrapped brachial artery) or irreducible fracture
    • Admit patients with displaced fractures or significant soft tissue injury for neurovascular observations

Fractures about the elbow

• Supracondylar fractures
  • Flexion-type (5%)
    • Rare due to direct anterior force against flexed elbow leading to anterior displacement of distal segment
    • Often open due to direct force
    • Displaced must be reduced with immediate ortho consult
    • Open reduction for vascular insufficiency or irreducible fracture
    • Admit for neurovascular obs if significant soft tissue injury or displaced fractures
  • Complications
    • Neurological (7%)
      • Posteromedial displacement – radial nerve
      • Posterolateral displacement – median nerve
      • Ulnar nerve mostly involved from pin placement only
      • Anterior interosseous nerve often involved (branch of median nerve)
        • No sensory component so have to test motor function with OK sign

Fractures about the elbow

• Supracondylar fractures
  • Complications cont…
    • Vascular
      • Absence of radial pulse common in children and suggests brachial artery injury even if hand is warm and well perfused
      • Reduce immediately, re-check and then consider vascular imaging/exploration
    • Volkmann’s ischaemic contracture
      • Compartment syndrome of forearm
      • Refusal to open the hand, pain with passive extension of fingers and forearm tenderness are all signs of impending compartment syndrome
      • Mere lack of a radial pulse DOES NOT indicate ischaemia unless accompanied by these other signs
      • Fasciotomy and brachial artery exploration indicated

Fractures about the elbow

• Intercondylar fractures
  • Assume any distal humerus fracture in an adult is intercondylar rather than supracondylar
  • Olecranon driven against humerus with separation of condyles
  • CT is useful for comminuted fractures and operative planning
  • Non-displaced
    • Stable and treated in long-arm cast at 90 degrees flexion and neutral forearm
  • Displaced, rotated or comminuted – Closed reduction if able for articular surface congruence +- ORIF
  • Admit if severe oedema or displaced for neurovascular obs

Fractures about the elbow

• Epicondyle fractures
  • Lateral epicondyle fractures
    • Almost never occur as anatomically protected, leading to lateral condyle fractures instead
    • If they do occur, typically avulsion injuries treated in long-arm 90 degrees flexion and supination with ortho referral
  • Medial epicondyle fractures
    • Extra-articular injuries seen in children and adolescents. 50% associated with elbow dislocation
    • If associated ulnar collateral ligament tear, medial epicondyle may get entrapped in joint
    • Must carefully test ulnar nerve function
    • Minimally displaced can be treated with cast and early ROM
    • ORIF required for open fractures, unstable joints, fragment displacement >5mm or intra-articular fragments
    • Long-arm cast at 90 degrees flexion in pronation
  • Complications of both are frequent and include nonunion, cubitus varus/valgus, ulnar nerve palsy and AVN
  • Surgical treatment is often preferred so consult with ortho prior to discharge

Fractures about the elbow

• Condyle fractures
  • Lateral condyle fractures occur in children and more common than medial
  • Medial condyle also mostly limited to children
  • Often confused with more common medial epicondyle fracture
  • Trochlea ossification centre does not appear until age 9, so often missed on radiographs
  • Non-displaced
    • Long-arm posterior slab and ortho referral
    • If displaced or neurovascular compromise, immediate ortho consult

Fractures about the elbow

• Trochlea fractures
  • Isolated fractures are rare. Usually with associated posterior elbow dislocation
  • X-ray often subtle and may require CT
  • Long-arm posterior cast and ortho consult as articular surface involvement often necessitates surgical repair
• Capitellum fractures
  • Isolated fractures are rare. Usually associated with radial head fractures
  • X-ray may be subtle and best appreciated on lateral view
  • Usually non-displaced as no tendinous or ligamentous attachments
  • CT often helpful
  • Posterior long-arm cast and ortho consult as articular in nature

Proximal ulna fractures

• All considered intra-articular
• Coronoid fractures
  • Usually with posterior elbow dislocation a trochlea driven into coronoid
  • CT often required to make diagnosis
  • Long-arm slab in flexion and supination and f/u within 24 hours with ortho
  • Conservative treatment remains controversial

Olecranon fractures

• Quite common representing 10% of upper limb fractures
• Classification
  • Type I – <2mm displacement. Sling
  • Type II – Displaced but ulnohumeral joint is stable. >3mm treated with tension banding or plate
  • Type III – Displaced and unstable. Operative.
• Associated open fractures, dislocations, radial head fractures and ulnar nerve injury are common
• Forearm extension against resistance is crucial as will often use gravity to extend forearm otherwise
• In adolescents, epiphysis ossifies at age 11 and fuses by age 16 so comparison films and fat pad sign can be helpful
• Treatment – Long arm posterior slab in flexion and f/u within 24 hours
• Non-operative only for elderly poorly functioning and non-displaced fractures with intact extensor mechanism

Radial head fractures

• Most common fractures of the elbow
• Associated injuries include fractures of capitellum, olecranon and coronoid, MCL injury, medial epicondyle avulsion fracture secondary to valgus stress and elbow dislocation
• Essex-Lopresti lesion
  • Radial head # + Disruption of triangular fibrocartilage of wrist + interosseous membrane
    • Leads to distal radioulnar dissociation and proximal radial migration if radial head excision is performed
• Pain in lateral elbow, esp. with supination/pronation

Radial head fractures

• Radiocapitellar line displacement and fat pads are good clues to diagnosis
• Non-displaced with no mobility restriction – Sling immobilisation in flexion with f/u in 1 week
• Displaced fractures, restricted ROM – surgical repair and ortho f/u within 24 hours
• Rule of 3’s (conservative management if):
  • <1/3 articular surface involved
  • <30 degrees angulation
  • <3mm depression

Radial head fractures

• Mason classification
  • Type I – Non-displaced  Treated conservatively
  • Type II – Partial articular fracture with displacement >2mm  ORIF
  • Type III – Comminuted involving entire radial head  Complete excision
  • Type IV – Fracture with elbow dislocation

Radial neck fractures

• Tenderness more distal than radial head and less pain on pronation/supination
• Conservative management
  • If <20 degrees angulation in adults (<30 degrees in children)
• Manipulation
  • Required if >20 degrees angulation in adults (>30 in children)
• Surgical
  • Gross displacement
  • Epiphyseal injuries

Forearm fractures

• Radius fractures between supinator (biceps brachii and supinator) and pronator teres results in marked displacement of segments (proximal segment supinated and distal segment pronated)
• If fracture distal to pronator teres, forces neutralise one another and get less displacement
• Careful attention to lateral bowing of radius, length, alignment and angulation are crucial

Forearm fractures

• Radius + Ulna
  • High-impact forces can produce comminuted and segmented fractures (often displaced)
  • Carefully assess NV status as great force often involved
  • Vascular compromise is uncommon due to excellent collateral circulation between ulnar and radial arteries
  • Rotational deformity
    • On AP view, radial styloid and radial tuberosity normally point in opposite directions
    • On lateral view, ulnar styloid and coronoid process point in opposite directions
    • Sudden change in bony width at fracture site also suggests rotation as oblong in cross-section (not circular)
  • Treatment
    • Non-displaced fractures in adults can be immobilised in long-arm casts and referred for follow-up
    • Any displacement requires urgent consult for ORIF

Forearm fractures

• Ulna fractures
  • Isolated distal 2/3 ulna shaft fracture (nightstick fractures)
    • Non-displaced = <50% displacement and <10 degrees angulation – Short-arm cast
    • Unstable = >50% displacement, with >10% angulation, or involving proximal third of ulna
      • Ortho consult for oRIF
      • Always assess for associated radial fracture or ligamentous/joint involvement
  • Monteggia fracture-dislocation
    • Fracture of proximal third of ulna with radial head dislocation
    • Rare in adults and peaks at age 4-10yo
    • Missing the radial head dislocation leads to chronic pain, reduced ROM and possible radial head excision later
    • 60% have anterior dislocation of radial head
    • Apex of ulna fracture points to the direction of radial head dislocation
    • Check radiocapitellar line to not miss this
    • Urgent ortho consult as usually treated with ORIF
    • Posterior interosseous nerve involvement must be ruled out

Forearm fractures

• Monteggia fracture-dislocation
  • Bado Classification
  • Type I (extension-type): # proximal or middle third of ulna with anterior angulation and anterior dislocation of radial head (60% and mostly children)
  • Type II (flexion-type): # proximal or middle third of ulna with posterior angulation and posterior dislocation of radial head (15% – mostly adults)
  • Type III: # ulnar metaphysis (distal to coronoid process) with lateral dislocation of radial head
  • Type IV: # of proximal or middle third of ulna and radius with radial head dislocation

Forearm fractures

• Proximal 2/3 of radius
  • Rare due to protection
  • Non-displaced fractures are rare but are treated in long-arm cast and f/u
  • Often displaced requiring ORIF
  • Some authors suggest all radial shaft fractures need ORIF
• Galeazzi fracture-dislocation
  • Distal radius fracture with distal RUJ dislocation
  • Ulna displaced dorsally and may have slightly widened DRUJ space on AP
  • 3x more common than Monteggia
  • Treated with ORIF

X-ray features of DRUj disruption

• Shortening of radius by 5mm
• Fractured ulnar styloid process
• Widened distal radioulnar joint space by 2mm
• Subluxation of DRUJ

Last Updated on October 6, 2020 by Andrew Crofton