LAB/ECG/X-Ray Rounds Grant Kennedy CCFP-EM resident

WRIST INJURIES

Wrist Injuries OBJECTIVES: *Brief review of anatomy *Review of common fractures/dislocations seen in the ED *Discuss appropriate ED treatment

X-Ray Assesment (PA) ADEQUACY: ADEQUACY: Distal Radius and Ulna should not overlap Distal Radius and Ulna should not overlap Axis of 3 rd metacarpal should parallel that of the radius. Axis of 3 rd metacarpal should parallel that of the radius. Lunate should articulate with both radius and ulna in 50:50 manner. Lunate should articulate with both radius and ulna in 50:50 manner.

X-Ray Assessment (PA) ALIGNMENT: ALIGNMENT: Joint spaces are uniform in width; 1-2 mm. Joint spaces are uniform in width; 1-2 mm. Adjacent bones have parallel surfaces Adjacent bones have parallel surfaces Excessive widening or narrowing suggests ligament disruption, carpal instability, or fracture/dislocations of at least one of the adjacent carpal bones. Excessive widening or narrowing suggests ligament disruption, carpal instability, or fracture/dislocations of at least one of the adjacent carpal bones.

X-Ray Assessment (PA) ALIGNMENT: ALIGNMENT: 3 smooth arcs outline the articular surfaces at the radiocarpal and midcarpal joints 3 smooth arcs outline the articular surfaces at the radiocarpal and midcarpal joints 2 of these arcs formed by proximal and distal surfaces of the scaphoid, lunate, and triquetrum 2 of these arcs formed by proximal and distal surfaces of the scaphoid, lunate, and triquetrum 1 formed by proximal articular surface of capitate and hamate in the midcarpal joint 1 formed by proximal articular surface of capitate and hamate in the midcarpal joint

X-Ray Assessment (PA) Radial styloid extends 9 to 12 mm beyond articular surface of distal ulna Radial styloid extends 9 to 12 mm beyond articular surface of distal ulna Ulnar slant of distal radius : 15 to 25 degrees Ulnar slant of distal radius : 15 to 25 degrees

X-Ray Assessment (Lateral) ADEQUACY: ADEQUACY: Radius and Ulna should completely overlap Radius and Ulna should completely overlap Radial styloid should be centered over the distal radial articular surface Radial styloid should be centered over the distal radial articular surface

X-Ray Assessment (Lateral) ALIGNMENT: ALIGNMENT: Axis of radius, lunate, capitate is collinear Axis of radius, lunate, capitate is collinear “Apple (capitate) in a cup (lunate) sitting on a saucer (radius)” “Apple (capitate) in a cup (lunate) sitting on a saucer (radius)” “3 C’s” “3 C’s”

X-Ray Assessment (Lateral) Distal radius has a normal volar tilt of 10 to 25 degrees Distal radius has a normal volar tilt of 10 to 25 degrees

X-Ray Assessment (Lateral) 3 C’s provide a gross assessment of carpal alignment 3 C’s provide a gross assessment of carpal alignment Measurement of capitolunate and scapholunate angles is a more precise assessment of carpal alignment. Measurement of capitolunate and scapholunate angles is a more precise assessment of carpal alignment.

X-Ray Assessment (Lateral) Axis of Lunate and Capitate should nearly overlap and form an angle <20 degrees Axis of Lunate and Capitate should nearly overlap and form an angle <20 degrees Axis of Lunate and Scaphoid should form an angle between 30 and 60 degrees. Axis of Lunate and Scaphoid should form an angle between 30 and 60 degrees. Deviation from these angles suggests ligament disruption and carpal instability. Deviation from these angles suggests ligament disruption and carpal instability.

Scapholunate Ligament Instability/Rupture 3 X-ray Findings: 3 X-ray Findings: 1. (PA): widening of >3mm of scapholunate joint. “Terry Thomas” 1. (PA): widening of >3mm of scapholunate joint. “Terry Thomas” 2. (PA) scaphoid has tilted towards the observer and is viewed more on its end. Circular cortex of bone becomes more prominent and appears as a ring. “Cortical Ring Sign” 2. (PA) scaphoid has tilted towards the observer and is viewed more on its end. Circular cortex of bone becomes more prominent and appears as a ring. “Cortical Ring Sign” 3. (Lateral): Dorsal Intercalated Segment Instability 3. (Lateral): Dorsal Intercalated Segment Instability

X-ray Assessment (Lateral) Dorsal Intercalated Segment Instability (DISI): Dorsal Intercalated Segment Instability (DISI): Lunate tilts dorsal Lunate tilts dorsal Axis of Lunate and Capitate >20 degrees Axis of Lunate and Capitate >20 degrees Scaphoid tilts palmar Scaphoid tilts palmar Axis of Lunate and Scaphoid >60 degrees Axis of Lunate and Scaphoid >60 degrees

Scapholunate Ligament Instability/Rupture Treatment: Treatment: Radial gutter splint Radial gutter splint Surgical referral Surgical referral

Triquetrolunate Instability

Triquetrolunate Ligament Instability 3 X-ray Findings: 3 X-ray Findings: 1. (PA): widening of triquetrolunate joint space 1. (PA): widening of triquetrolunate joint space 2. (PA): obliteration of capitolunate joint space because of volar tilt of the lunate. 2. (PA): obliteration of capitolunate joint space because of volar tilt of the lunate. 3. (Lateral): Volar Intercalated Segment Instability 3. (Lateral): Volar Intercalated Segment Instability

X-Ray Assessment (Lateral) Volar Intercalated Segment Instability (VISI): Volar Intercalated Segment Instability (VISI): Lunate tilts volar Lunate tilts volar Axis of Lunate and Capitate >20 degrees Axis of Lunate and Capitate >20 degrees Axis of Lunate and Scaphoid remains normal at degrees Axis of Lunate and Scaphoid remains normal at degrees

Triquetrolunate Ligament Instability

Treatment: Treatment: Ulnar gutter splint in ER Ulnar gutter splint in ER Surgical referral Surgical referral

Perilunate Dislocation Mechanism: FOOSH with Forceful Dorsiflexion Mechanism: FOOSH with Forceful Dorsiflexion Tearing of scapholunate, radiocapitate, lunatotriquetral ligaments Tearing of scapholunate, radiocapitate, lunatotriquetral ligaments Opening of space of Poirier Opening of space of Poirier Capitate displaced posteriorly Capitate displaced posteriorly Lunate retains contact with radius Lunate retains contact with radius

Perilunate Dislocation X-Ray Findings: X-Ray Findings: 1. (Lateral). Linear arrangement of 3 C’s disrupted, with capitate (3 rd C) displaced posterior. Lunate maintains contact with radius. 1. (Lateral). Linear arrangement of 3 C’s disrupted, with capitate (3 rd C) displaced posterior. Lunate maintains contact with radius. 2. (PA). 3 smooth arcs are disrupted, capitolunate joint space is obliterated as bones overlap one another. “crowded carpals” 2. (PA). 3 smooth arcs are disrupted, capitolunate joint space is obliterated as bones overlap one another. “crowded carpals”

Perilunate Dislocation Watch for associated fractures. Watch for associated fractures. Scaphoid and capitate most common. Scaphoid and capitate most common. Treatment: Treatment: Reduce in ER Reduce in ER Long arm splint Long arm splint Surgical referal Surgical referal

Lunate Dislocation Mechanism: Mechanism: Similar to perilunate (disruption of many ligaments) plus… Similar to perilunate (disruption of many ligaments) plus… After being displaced posteriorly, capitate rebounds with sufficient force to push the lunate off the radius and into the palm. After being displaced posteriorly, capitate rebounds with sufficient force to push the lunate off the radius and into the palm.

Lunate Dislocation X-Ray Findings: X-Ray Findings: 1. (PA). Lunate has a triangular shape “piece-of-pie” sign. Pathognomonic. 1. (PA). Lunate has a triangular shape “piece-of-pie” sign. Pathognomonic. 2. (Lateral). Disruption of 3 C’s. Lunate (middle C) has been pushed off the radius into the palm. “Spilled Tea-Cup”. 2. (Lateral). Disruption of 3 C’s. Lunate (middle C) has been pushed off the radius into the palm. “Spilled Tea-Cup”.

Lunate Dislocation Treatment: Treatment: Closed Reduction Closed Reduction Long arm Splint Long arm Splint Surgical Referral Surgical Referral

Scaphoid Fracture X-Rays: Scaphoid views should be obtained. X-Rays: Scaphoid views should be obtained. X-Ray negative, but clinically suspicious = cast and re x-ray days X-Ray negative, but clinically suspicious = cast and re x-ray days Treatment: Treatment: Proximal/mid = long-arm thumb-spica x 4-6 wks Proximal/mid = long-arm thumb-spica x 4-6 wks Distal = short arm thumb spica. Distal = short arm thumb spica. REFER: displaced > 1mm, comminuted, carpal instability pattern noted REFER: displaced > 1mm, comminuted, carpal instability pattern noted Risk Factors for AVN: proximal, oblique, or displaced Risk Factors for AVN: proximal, oblique, or displaced

Triquetrum Fracture X-Ray: X-Ray: Avulsion # best seen as tiny flake of bone on dorsum of triquetrum on lateral x-ray Avulsion # best seen as tiny flake of bone on dorsum of triquetrum on lateral x-ray Treatment: Treatment: Avulsion: wrist splint x 1-2 weeks Avulsion: wrist splint x 1-2 weeks Body (non-displaced): short arm cast x 6 weeks Body (non-displaced): short arm cast x 6 weeks Body (displaced >1mm): refer Body (displaced >1mm): refer

Lunate Fracture X-ray: clinical suspicion should dictate acute treatment, as # may be missed X-ray: clinical suspicion should dictate acute treatment, as # may be missed Risk of AVN due to distal to proximal blood supply. Risk of AVN due to distal to proximal blood supply. Keinbock disease = AVN, can lead to lunate collapse, OA, chronic pain, weak grip Keinbock disease = AVN, can lead to lunate collapse, OA, chronic pain, weak grip Treatment: thumb spica and refer all Treatment: thumb spica and refer all

Trapezium Fracture Treatment: Treatment: Non-displaced = thumb-spica x 6 wks Non-displaced = thumb-spica x 6 wks Displaced > 1mm = Refer Displaced > 1mm = Refer

Pisiform Fracture

Sesamoid bone within the flexor carpi ulnaris tendon Sesamoid bone within the flexor carpi ulnaris tendon Exam: Pisiform and hook of Hamate form walls of Guyon’s canal. Rule out injury to ulnar nerve and artery. Exam: Pisiform and hook of Hamate form walls of Guyon’s canal. Rule out injury to ulnar nerve and artery. Treatment: splint in 30 degrees flexion, ulnar deviation to relax tension from FCU, vs. short arm cast x 4-6 weeks. Treatment: splint in 30 degrees flexion, ulnar deviation to relax tension from FCU, vs. short arm cast x 4-6 weeks.

Hamate Fracture Exam: R/O injury to ulnar nerve/artery Exam: R/O injury to ulnar nerve/artery Treatment: Treatment: Non-displaced body/ Hook # = short arm cast including 4 th /5 th MCPs x 4-6 weeks w/ f/u Non-displaced body/ Hook # = short arm cast including 4 th /5 th MCPs x 4-6 weeks w/ f/u Displaced = volar splint + refer Displaced = volar splint + refer

Less Common Fractures Capitate Fracture: Capitate Fracture: Potential for AVN (like lunate, scaphoid) Potential for AVN (like lunate, scaphoid) Treat with short arm splint (if swollen) vs. short arm cast + refer Treat with short arm splint (if swollen) vs. short arm cast + refer Displaced = splint + refer Displaced = splint + refer Trapezoid Fracture: Trapezoid Fracture: x-rays often negative. Tx with thumb spica x-rays often negative. Tx with thumb spica