267. Injuries to the Elbow and Forearm

Anatomy

Radial nerve: transverses lateral epicondyle. Motor: wrist and finger (posterior interosseus nerve branch) extension. Sensory: dorsal aspect of hand from thumb to middle of ring finger. Test: extend wrist and fingers against resistance, sensation to dorsal thumb webbing.

Median nerve: down the middle. Motor: wrist/finger flexion. Sensory: volar aspect of hand from thumb to middle of ring finger.Test: OK sign with thumb/index finger assesses anterior interosseous branch, Thumb’s up (abduction) assesses recurrent branch; sensation to tip of index finger.

Ulnar nerve:’funny bone;’ wraps around lateral epicondyle. Motor: intrinsic hand muscle. Sensory: ulnar side ring finger and 5th finger. Test: abduction of the fingers, particularly index finger with resistance, little finger sensation.

Xrays

Several lines to look at for subtle/occult fractures.

Anterior humeral line: On lateral view, anterior line of humuer should go through middle 1/3 of capitellum. If displaced, consider supracondylar fracture.

Radiocapitellar line: On lateral view, line through center of radius should transect radial head and capitellum. If displaced, consider radial head fracture or dislocation.

Other xrays: Greenspan view looks at radial head/capitellum view.

Anterior fat pad: should be thin line anterior to distal humerus. Sail sign: large anterior fat pad likely related to fracture: intra-articular involvement.

Posterior fat pad: should not be present. Any fat pad posteriorly likely represents intra-articular involvement.

Pediatric ossification centers: in chronologic order, use mneumonic CRITOE: capitellum, radial head, internal epicondyle, trochea, olecrannon, external epicondyle. Also dirty phrase: Come Rub My Tree Of Love. Radiopedia Video.

Injuries

Biceps rupture: nearly all proximal, caused by resisted overuse/contraction. Usually snap/pop sensation, pain to anterior shoulder with midarm ball. Flexion of elbow in aduction/external rotation will elicit pain. Not necessarily weak due to other accessory muscles. Distal biceps rupture rare, felt in antecubital fossa, does have strength loss. Treatment: sling, ice, ortho referral. Usually surgical repair.

Triceps rupture: rare, unable to extend elbow. Treatment: sling, ice, ortho referral. Complete tear requires surgery.

Lateral epicondylitis: ‘tennis elbow.’ Overuse injury. Tenderness over lateral epicondyle. Pain with forced extension and supination of forearm against resistance. Treatment: rest, ice, NSAIDs, counterforce brace.

Medial epicondylitis: ‘golfer’s elbow.’ Basically opposite of tennis elbow. Medial epicondyle. Pain with forced flexion, pronation of forearm, also sometimes have ulnar neuropathy. Treatment: rest ice, NSAIDs, counterforce brace.

Elbow Dislocation: 90% are posterolateral. Usually present with elbow in 45 degrees of flexion. Check neurovascular complications (usually ulnar). Associated fractures: coronoid process and radial head (all 3 make up ‘terrible triad’). Reduction:longitudinal traction with downward pressure on forearm. Have countertraction as well. Distal traction is continued and elbow is flexed. Alternative: put hands on posterior humerus with elbow flexed at 90 degrees. Put both thumbs on olecrannon and rotate it back into place. Consider putting elbow flexed on backing of chair. Splint in long arm posterior mold with elbow flexed at 90 degrees. Simple reductions can have early ROM after 1 week (with ortho referral and clearance).

Supracondylar Fractures: most common fracture of elbow in children. FOOSH with 95% extension type injuries. Displaced fractures must be reduced and require emergent ortho consult. Look for anterior humeral line on xray for subtle fractures. Always for median nerve (anterior interosseous branch) and radial artery involvement: distal radial pulse as well as OK sign with thumb/index finger. Complication: Volkmann is a compartment syndrome due to post-ischemic swelling.

Nursemaid’s Elbow: radial head subluxation, seen in the very young (1-4 years old). Radial head displaced out of annular ligament. Treatment: squeeze proximal forearm, extend elbow, supinate forearm, then flex. If still having pain, get xray. If still considered nursemaid’s, do same thing, but hyperpronate instead.

Nightstick Fracture: isolate midshaft ulnar fracture from direct blow. Treatment: splint in short arm splint. Fractures >50% displaced, 10% angulation, or involving proximal 1/3 are unstable for likely ORIF.

Radial Head Fractures: most common fractures of the elbow. FOOSH. Usually associated with other injuries. Can affect DRUJ (distal radius ulna junction) called Essex-Lopresti lesion. Look for fat pad abnormalities and Greenspan xray view. Also radiocapitellar line. Treatment: nondisplaced with sling. Displaced usually need surgical repair and referral in 24 hours.

Monteggia Fracture: Proximal third ulna with radial head dislocation. Typically in diaphyseal with anterior dislocation. Apex of ulna fracture points in direction of radial dislocation. Treatment: ORIF.

Galeazzi Fracture: Distal third radial fracture with dislocation of distal radioulnar joint. FOOSH. “Reverse Monteggia” fracture. GRUM mneumonic (GR for Galeazzi/Radius and UM for Ulna/Monteggia). Treatment: ORIF.

Other Fractures (Intercondylar, epicondyle, Trochea, Capitellum, Coronoid): Treat with long arm splint (splint from axilla to proximal to MCP with 3/4 arm encircled and elbow flexed to 90 degrees) with ortho referral.


 

Board Questions

Q1. What nerve is most commonly injured with a supracondylar fracture?

A1. Anterior Interosseous nerve. Wrong answers: Radial, ulna, musculocutaneous.

Q2. What is the most common elbow fracture in adults?

A2. Radial head fracture. Wrong answers: supracondylar, trochea, coronoid, etc.

Q3. What nerve is being tested for motor deficits with the “OK sign” with thumb/index fingers?

A3. Anterior interosseous nerve. Wrong answers: Radial, ulnar, posterior interosseous, recurrent branch of median nerve.

Q4. Which ossification center ossifies last in adolescents?

A4. Lateral epicondyle. Wrong answers: Medial epicondyle, olecrannon, trochea, etc.

Q5. Which type of fracture is this?

 

A5. Monteggia Fracture. Wrong answers: Galeazzi fracture, Nightstick fracture, Radial Head fracture, Supracondylar Fracture.


Clinical Cases

None yet


References/Resources

Tintinalli, Seventh Edition, Chapter 267: Injuries to the Elbow and Forearm.

CrashingPatient, Scott Weingart, Humerus and Elbow, Reviewed 11/19/15.

Radiopedia, Elbow ossification (mneumonic) Video.

Academic Life in EM, Tricks of the Trade: Nursemaid elbow reduction, Fred Wu, Reviewed 11/19/15.

267. Injuries to the Elbow and Forearm

266. Wrist Injuries

Anatomy

8 carpal bones: Scaphoid, Lunate, Triquetrum, Pisiform (proximal row – noted as crease on volar as of wrist), Trapizeum (umm..beside the thUMb), Trapezoid, Capitate, Hamate (Distal row – very stable) (Mneumonic: Some Lovers Try Positions They Can’t Handle – Scrubs Video).

Carpal Bones

No direct tendons on carpal bones.Two arches of ligaments basically centered around the lunate. Space between them is Space of Poirier which is a weakness point (dislocations).

Anatomic Snuffbox: scaphoid location. Triangle of bony radial styloid proximally, extensor pollicis brevis tendon radially, and extensor pollis longus (big tendon connected to thumb when you abduct) ulnarally.

Radiographs

PA view: No radius/ulnar overlap, 3rd metacarpal should be parallel with radius. Gilula arcs (3 arcs): proximal and distal lines of proximal row, proximal line of capitate/hamate. All should be 1-2mm separation between each other. Scaphoid should be elongated. Distal radius should articulate with 1/2 the lunate. Best view for looking for: scapholunate dissociation,

Lateral view: Three Cs: radius, lunate, and capitate. Look at angles of axis of scaphoid and lunate (should be between 30-60 degrees). Radius volar tilt should be less than 10-15 degrees. Best view for looking for: perilunate/lunate dislocation, distal radius fractures, capitate fracture.

Scaphoid view: cone-down PA view of scaphoid in ulnar deviation. Best view for looking for: scaphoid fractures.

Oblique view: Best view for looking for: trapezium fracture.

Carpal tunnel view: view thru carpal tunnel. Best view for looking for: pisiform and hook of hamate fractures.

Injuries

3 Dislocations of worsening severity in carpal instability: scapholunate dissociation, perilunate dislocation, and lunate dislocation. All outstretched hand, forceful dorsiflexion.

Scapholunate dissociation: MCC injuried wrist ligament. Look for >3mm (usually 5mm) of widening between scaphoid and lunate on PA view. Terry Thomas sign. Scaphoid tilts shortening it on PA view and appears as signet ring. Can get clenched fist view to furthur separate space. Treatment: radial gutter splint or short arm volar posterior mold. Usually require pinning or ORIF.

Scapholunate Dissociation

Perilunate dislocation: continued tear around volar ligament. Usually associated carpal bone fractures. Swelling/pain, usually no gross deformity. Lateral view: capitate displaced dorsally from the lunate. Lunate keeps contact with radius. PA view: capitolunate space is missing, bones overlapping. Add trans + carpal bones to beginning of nomenclature is associated fracture. Treatment: emergent reduction, ortho consult. If able to reduce, long arm splint. Usually will have failed reduction and need OR.

Perilunate Dislocation

Lunate dislocation: Most severe of the 3. PA view: lunate appears triangle shape (‘piece of the pie’). Lateral view: lunate has dislocated off radius (spilled teacup). Treatment: same as perilunate: emergent reduction, ortho consult. Likely reduction unsuccessful and needs OR. Complications: median nerve compression.

Lunate Dislocation

Scaphoid fracture: MCC carpal bone fractured. Axial load to thumb. Anatomic snuffbox tenderness. Look at soft tissue fat pad adjacent to radial aspect. Has distal radial blood supply leading to avascular necrosis if not properly treated. 10-20% missed on xrays. If clinical suspicion, treat. Splint in dorsiflexion/radial deviation short arm thumb spica. Usually will need pinning.

Triquetrum fracture: Second most common carpal fracture. Dorsal tenderness distal to ulnar styloid.  Avulsion (resisted twisting) has excellent prognosis and if minimally tender, early ROM is fine. Stable body fractures (direct trauma) require cast for 6 weeks.

Lunate fracture: usually associated with other fractures. Distal blood supply as well (Kienbock disease – avascular necrosis of lunate). Treatment: short arm thumb spica splint.

Trapezium fracture: saddle shaped bone articulates with thumb metacarpal. Painful thumb movement and weak pinch. Best viewed on oblique view xray. Treatment: short arm thumb spica splint.

Pisiform fracture: sesamoid bone in flexor carpi ulnar tendon. Both pisiform and hook of hamate form Guyon canal (contains ulnar artery/nerve). Last bone to ossify (12yo). Treatment: 30 degree flexion/ulnar deviation.

Hamate fracture: most are hook of hamate fractures – interrupted swing with club. Hypothenar pain and gripping pain. Hook of Hamate pull test: supinated, ulnar deviated wrist, resisted flexion of 4th-5th fingers. Best view with carpal tunnel view. Look for Guyon canal injury. Treatment: splint.

Capitate fracture: Usually associated with scaphoid fracture – scaphocapitate syndrome. Best viewed on lateral view. Treatment: splint.

Trapezoid fracture: extremely rare.

Colles fracture: distal radius metaphysis fracture with dorsal angulation. Outstretched hand, wrist extended. Dinner-fork deformity. Unstable fracture > 20 degrees. Treatment: Reduce by push fracture distal and palmarly. Splint 15 degree flexion/ulnar in sugar tong. F?u 7-10 days. Complications: median nerve compression, extensor pollicus longus (EPL) rupture (long term, due to blood supply).

Smith fracture: reverse Colles fracture. volar angulated fracture. Treatment: same as Colles.

Barton fracture: Colles or Smith fracture (more common of the two) with intraarticular involvement. Treatment: sugar tong, unstable fractures require ORIF.

Radial styloid fracture: usually associated with lunate dislocation.

Distal Radioulnar Joint Disruption (DRUJ): associated with intraarticular or distal radius shaft fractures (Galeazzi). Lateral view shows volar (most common) /dorsal ulna displacement. Can occur in isolation, though rare. Pronation limited. Treatment: splint, may require reconstructive surgery.


Board Questions

Q1.  Whats the difference between a Colles fracture and a Barton fracture?

A1. Barton’s has intra-articular involvement. Other wrong answers: reverse colles (volar angulation), scaphoid involvement, Galleazzi fracture, etc.

Q2. What other carpal bone is fractured with a captitate fracture?

A2. Scaphoid. Other wrong answers: lunatate, hamate, trapezius, 3rd metacarpal.

Q3. What carpal fractures are best viewed with a carpal tunnel view xray?

A3. Pisiform and hook of hamate. Other wrong answers: Scaphoid and lunate, scaphoid and capitate, colles fracture, etc.

Q4. Which fracture occurs with resisted twisting on the wrist and has excellent prognosis?

A4. Triquetrum avulsion fracture. Other wrong answers: hook of hamate, pisiform, trapezium fracture.

Q5. Whats the most common carpal bone fractured?

A5. Scaphoid. Other wrong answers: Lunate, capitate, hook of hamate, etc.

Q6. What type of injury is this?

Lunate Dislocation

A6. Lunate dislocation. Other wrong answer: perilunate dislocation, capitate dislocation, normal wrist, etc.


Clinical Cases

Life in the Fast Lane, Stairs vs Wrist (FREE)

Life in the Fast Lane, FOOSH Interpretation (FREE)

Life in the Fast Lane, FOOSH Interpretation 002 (FREE)

Life in the Fast Lane, FOOSH Interpretation 003 (FREE)


References / Resources

Tintinalli, Seventh Edition, Chapter 266: Wrist Injuries

CrashingPatient, Scott Weingart, Wrist and Forearm, Reviewed 11/9/15 (FREE)

EMedHome, Wrist Injuries, Josh Broder

Emergency Medicine Ireland, Andy Neill, Anatomy of EM 018: Scapholunate Injurie (FREE)

Emergency Medicine Ireland, Andy Neill, Anatomy of EM 019: Scaphoid Fractures (FREE)

Emergency Medicine Ireland, Andy Neill, Anatomy of EM 017: Colles Fractures (FREE)

ERCast, Rob Orman, Distal Radius Fractures (FREE)

Radiopedia.org (FREE)

Life in the Fast Lane, Peter Allely, Scaphoid Fractures: The ED Perspective (FREE)

Life in the Fast Lane, Mike Cadogan, Isolated Volar Distal Ulnar Dislocation (FREE)

YouTube, Larry Mellick, Distal Radius Fracture Reduction and Hematoma Block Video (FREE)

YouTube, Julie B, Ultrasound Reduction Video (FREE)

Wheeless Online, Wrist Menu (FREE)


266. Wrist Injuries