MSK Trauma

Table of Contents

MSK Trauma Quick Reference Guides

For spine imaging please see the neuroradiology section.



Lateral Wrist Bony Anatomy

Wrist Ligaments

Ankle Ligaments


Lines of the Pelvis: iliopectineal (red), ilioischial (purple), anterior rim (blue), posterior rim (brown), Shenton (yellow), teardrop (green), obturator (orange), and sacral arcs (white)

Source: Khurana B, Sheehan SE, Sodickson AD, Weaver MJ. Pelvic ring fractures: what the orthopedic surgeon wants to know. Radiographics. 2014;34(5):1317-1333. doi:10.1148/rg.345135113

Lines of the acetabulum: ileopectineal line (yellow), ilioischial line (purple), anterior acetabular wall (green), posterior acetabular wall (red)

Source: Scheinfeld MH, Dym AA, Spektor M, Avery LL, Dym RJ, Amanatullah DF. Acetabular fractures: what radiologists should know and how 3D CT can aid classification. Radiographics. 2015;35(2):555-577. doi:10.1148/rg.352140098

Proximal Femur Anatomy



*Gamekeeper’s thumb can cause a Stener lesion – entrapment of the adductor pollicis muscle between the ulnar collateral ligament and the MCP joint – surgical lesion. Can only be delineated on MRI. DO NOT obtain stress views if Gamekeeper’s thumb injury is seen/suspected as you can cause a Stener lesion.


Distal Radius Fractures

Reporting Checklist

  • Loss of volar tilt
  • Loss of radial inclination
  • Shortening of the radius relative to the ulna
  • Intraarticular extension
  • Diastasis or depression at the intraarticular fracture site
  • Comminution
  • Associated ulnar styloid fracture
    • Location and degree of displacement
    • If styloid base fracture, is the DRUJ and TFCC intact
  • Disruption of the carpal arcs

Named Fractures

  • Just describe the fracture, don’t use eponyms

Galeazzi Fracture-Dislocation

Reporting Checklist

  • Description of radial fracture
  • Degree of shortening
  • DRUJ dislocation direction
  • Fracture of the distal radius with dislocation of the DRUJ
  • Classification
    • Type I: dorsal displacement of the distal radius
    • Type II: volar displacement of the distal raidus

Essex-Lopresti fracture-dislocation

  • Fracture of the radial head with dislocation of the DRUJ and rupture of the interosseous membrane


Radial Head Fractures

Reporting Checklist

  • Degree of displacement
  • Amount of articular surface involved (%)
  • Presence of comminution or dislocation

Mason-Johnston Classification

  • Type 1 – No or minimal (<2mm) displacement
  • Type 2 – Displacement >2mm, >30% <50% articular surface involvement
  • Type 3 – Comminution of the radial head without dislocation
  • Type 4 – Comminution and dislocation of the radial head

Elbow Dislocation

  • Posteriolateral most common
  • Complex = dislocation + fracture
  • Associated fractures
    • Medial epicondyle
    • Radial head/neck
    • Coronoid process
  • Terrible triad – get CT if 2/3 seen to exclude the third injury
    • Posterior elbow dislocation
    • Radial head fracture
    • Coronoid process fracture

Stages of Dislocation

  • Stage 1 – Damage to lateral ligamentous structures (LUCL, RCL)
    • Posterolateral rotary instability
  • Stage 2 – Capsular and lateral soft tissue damage
    • Trochlea is perched on the coronoid process
  • Stage 3 – Vary degrees of damage to medial structures (anterior bundle MCL) with frank dislocation

Monteggia Fracture Dislocation

  • Ulnar fracture with proximal radius dislocation
  • All will go to surgery

Bado Classification

  • Type 1 – Most Common – Anterior angulation of the ulnar fragment apex with anterior dislocation of the radius
  • Type 2 – Posterior fracture angulation of the ulna and radial head
  • Type 3 – Pediatrics – Ulnar metaphyseal fracture with lateral dislocation of the radial head
  • Type 4 – Fracture of the proximal radius and ulna
Source: @ShujaatTaimur Twitter


Reporting Checklist

  • Column involvement – medial or lateral
  • Direction and degree of displacement of epicondylar avulsion fractures and single column fractures
  • Presence of comminution or two column injury

Classification System

Source: Sheehan SE, Dyer GS, Sodickson AD, Patel KI, Khurana B. Traumatic elbow injuries: what the orthopedic surgeon wants to know. Radiographics. 2013 May;33(3):869-88. doi: 10.1148/rg.333125176. PMID: 23674780.

Coronoid Process Fractures

Classification System

  • Type 1 – Transverse tip fracture
  • Type 2 – Anteromedial facet involvement – MCL injury
  • Type 3 – Base of coronoid process (>50% disruption)

Olecranon Fractures

Reporting Checklist

  • Degree of displacement
    • >2mm displacement = surgery
  • Presence of comminution
    • Comminution = surgery

Mayo Classification System

  • Type 1 – Non-displaced
  • Type 2- Intact MCL, displaced >3mm
  • Type 3 – Displaced, unstable


Reporting Checklist

Source: Sandstrom CK, Kennedy SA, Gross JA. Acute shoulder trauma: what the surgeon wants to know. Radiographics. 2015 Mar-Apr;35(2):475-92. doi: 10.1148/rg.352140113. PMID: 25763730.
  • Typically do not list the parts since the ortho may disagree
  • Part = >1cm displacement or 45 degree angulation


Clavicle Fracture

Reporting Checklist

  • Fracture location along the shaft (lateral third, middle third, medial third)
  • Angulation and fracture end displacement (including direction)
  • Comminution
  • Degree of overlap
  • Acromioclavicular and sternoclavicular joint integrity
  • Coracoclavicular distance

In general, if >100% displacement will be managed operatively

Rockwood Classification of Acromioclavicular Joint Injury

Type IClavicle not elevated relative to the acromion
Type IIClavicle elevated but not above the superior border of the acromion
Type IIIClavicle elevated above the superior border of the acromion
CC distance is less than twice normal (<25 mm)
Type IVClavicle displaced posterior into the trapezius
Type VClavicle is elevated and CC distance is more than double normal (>25 mm)
Consider weight-bearing projections
Type VIRare; clavicle inferiorly displaced behind coracobrachialis and biceps tendons
Type I-III is generally nonoperative; IV-VI operative management


Reporting Checklist

Source: Sandstrom CK, Kennedy SA, Gross JA. Acute shoulder trauma: what the surgeon wants to know. Radiographics. 2015 Mar-Apr;35(2):475-92. doi: 10.1148/rg.352140113. PMID: 25763730.

Commonly involves:

  • Scapular body
  • Acromion
  • Coracoid process
  • Glenoid neck or articular surface (requires surgical repair)

Superior Suspensory Complex – support complex of the shoulder. Disruption of any two = unstable injury requiring surgery. Disruption of three = floating shoulder (high energy trauma)

  1. Glenoid process
  2. Coracoid process
  3. Coracoclavicular ligament
  4. Distal end of the clavicle
  5. Acromioclavicular joint
  6. Coracoacromial ligament
  7. Acromial process

Scapular Neck Fracture Classification

  • Type 1 – Nonangulated, nondisplaced
  • Type 2a – Shortened or displaced > 1 cm
  • Type 2b – Angulated > 40 degrees

Ideberg Classification of Glenoid Fossa Fractures

Type 1aAnterior rim
Type 1bPosterior rim
Type 2Transverse  to lateral margin
Type 3Transverse to superior margin
Type 4Transverse to medial margin
Type 5aTransverse lateromedial
Type 5bTransverse superomedial
Type 5cTransverse superomediolateral
Type 6Comminuted crush
Source: UW Emergency Radiology


Stable Pelvic Fractures

  • Isolated pubic ramus of ischium fracture
  • Unilateral fractures of both rami
  • Isolated sacral fractures (usually transverse)
  • Avulsion fractures
  • Duverney fracture – peripheral fracture to the iliac wing (associated with ileus)

Pelvic Ligaments

Young and Burgess Classification of Pelvic Ring Fractures



Judet and Letournel classification of Acetabular Fractures

Anterior Column – Pelvic brim, anterior wall, superior pubic ramus, anterior iliac wing

Posterior Column – Greater and lesser sciatic notch, posterior wall, ischial tuberosity

Source: Scheinfeld MH, Dym AA, Spektor M, Avery LL, Dym RJ, Amanatullah DF. Acetabular fractures: what radiologists should know and how 3D CT can aid classification. Radiographics. 2015 Mar-Apr;35(2):555-77. doi: 10.1148/rg.352140098. PMID: 25763739.


Source: Sheehan SE, Shyu JY, Weaver MJ, Sodickson AD, Khurana B. Proximal Femoral Fractures: What the Orthopedic Surgeon Wants to Know. Radiographics. 2015 Sep-Oct;35(5):1563-84. doi: 10.1148/rg.2015140301. Epub 2015 Jul 17. Erratum in: Radiographics. 2015 Sep-Oct;35(5):1624. PMID: 26186669.

Types of Fractures

Intracapsular Fractures

Pipkin Classification of Femoral Head Fractures

Type IInferior to the fovea centralis
Type II Superior to the fovea centralis
Type IIICombination of type I/II with femoral neck fracture
Type IVCombination of type I/II with acetabular fracture


Reporting Checklist

  • Type of dislocation
    • Posterior > anterior
  • Associated femoral neck fracture
    • Reduction is contraindicated with coexisting femoral neck fracture
  • Associated femoral head impaction fracture
    • More common with anterior dislocation
    • Requires THA
Osteochondral impaction fracture. Source: Sheehan SE, Shyu JY, Weaver MJ, Sodickson AD, Khurana B. Proximal Femoral Fractures: What the Orthopedic Surgeon Wants to Know. Radiographics. 2015 Sep-Oct;35(5):1563-84. doi: 10.1148/rg.2015140301. Epub 2015 Jul 17. Erratum in: Radiographics. 2015 Sep-Oct;35(5):1624. PMID: 26186669.

Femoral Neck Fractures

Reporting Checklist

  • Location
    • Subcapital
    • Transcervical
    • Basicervical
  • Displaced or nondisplaced
  • If elderly – Garden Classification – the worse grade the higher risk of AVN

Garden Classification of Femoral Neck Fractures

Type 1Incomplete or valgus impacted
Type 2Complete, nondisplaced
Type 3Complete, partially displaced
Type 4Complete, fully displaced

Extracapsular Fractures

Intertrochanteric Fractures

Reporting Checklist

  • Involvement of the posteromedial cortex
    • If intact = stable
    • If involved = unstable
  • Reverse fracture – unstable
  • Subtrochanteric extension – unstable

Evan-Jensen Classification of Intertrochanteric Fractures

Type ITwo-part nondisplaced fractureStable
Type IITwo-part minimally displaced fractureStable
Type IIIThree-part with loss of posterolateral supportStable
Type IVThree-part with loss of posteromedial supportUnstable
Type VFour-part with loss of both posteromedial and lateral supportUnstable
Type RReverse obliquity fractureUnstable

Lesser Troachanter Fracture – if isolated think malignancy

Subtrochanteric Fractures

  • High rate of complications
  • Trauma – comminuted fractures
  • Elderly – spiral fractures
  • Bisphosphonate therapy
    • Transverse (primarily); medially may be oblique
    • Lateral cortex, medial spike if complete fracture
    • No or minimal comminution
    • Endosteal or periosteal thickening

Seinsheimer Classification of Subtrochanteric Fractures

Type 1Any fracture with <2mm displacement
Type 2ATwo-part transverse fracture
Type 2BTwo-part spiral fracture with the lesser trochanter in the proximal fragment
Type 2CTwo-part spiral fracture with the lesser trochanter in the distal fragment
Type 3AThree-part spiral fracture, the third fragment is the lesser trochanter
Type 3BThree-part fracture with third part a butterfly fragment
Type 4Four or more fragments
Type 5Any fracture with extension into the greater trochanter


Distal Femur Fractures

Reporting Checklist

  • Fracture fragments
  • Articular or extraarticular
    • If articular measure the articular surface step-off
  • Presence of floating knee – extra-articular fractures of the proximal tibia and distal femur
  • If fracture recommend inmaging of the proximal femur and hip
  • If posterior displocation – recommend CTA to evaluation popliteal injury

AO/OTA Classification of Distal Femur Fractures

A1Simple, nondisplaced
A2Metaphyseal wedge  
A3 Complex metaphyseal
B1Sagittal fracture of the lateral condyle
B2Sagittal fracture of the medial condyle
B3Coronal fracture of one or both condyles (Hoffa fragment)
C1Simple articular and metaphyseal
C2Comminuted metaphyseal component with simple articular componenet
C3Comminuted articular and metaphyseal components

Fibular Fractures

Reporting Checklist

  • Location of fracture (fibular head, avulsion, fibular shaft)
    • Fibular head fracture – asociated with peroneal nerve injury and foot drop
      • Also association with posterolateral corner injury and instability
    • Fibular shaft fracture – Recommend imaging of ankle to exclude a Maisonneuve fracture 
  • Degree of subluxation
    • Anterolateral
    • Posteromedial
    • Superior

Patellar Fractures

  • Transverse fracture most common
  • Sugical management
    • >2mm incongruity at articular surface
    • >3mm separation of fracture fragments
    • Disruption of extensor mechanism

AO/OTA Classification of Patellar Fractures

Plain Film Signs of Ligamentous Injury

  • Tibial spine avulsion fracture – associated with MCL and medial meniscus injury
    • Can be isolated and cause knee instability
    • If seen – recommend MRI

Deep Notch Sign – impaction fracture of the lateral femoral condyle associated with ACL injury

Source: Mirvis, Stuart E. Problem Solving In Emergency Radiology Expert Consult – Online. Elsevier Health Sciences, 2014.

Tibial Fractures

Reporting Checklist

  • Size, number and location of fracture fragments and fracture lines
  • Presence of contralateral joint space widening
  • Split, depressed, or bicondylar morphology
    • Nonsurgical management if diastasis <3-4 mm and depression <4-5mm

Schatzker Classification of Tibial Plateau Fractures

Type ISplit fracture with no depression
Type IILateral split fracture with depression of the weight bearing portion
Type IIIFocal depression of articular surface without split
Type IVMedial plateau fracture
Type VBicondylar split fracture +/- depression
Type VIBicondylar split fracture with dissocation of the metaphysis from diaphysis by transverse fracture component

Knee Dislocation

  • Based on the direction of the tibia
  • Anterior most common
  • Posterior – dashboard injury
  • Can have medial or lateral as well as rotary dislocation
  • All should undergo vascular imaging to evaluate for popliteal injury

Proximal Tibiofibular Joint Dislocation

Ogden Classification of PTFJ Dislocation

Type IPTFJ subluxation
Type IIAnterolateralMost common
Type IIIPosteromedialAssociated with peroneal nerve injury (foot drop)
Type IVSuperiorAssociated with fracture/dislocation of ankle or distal tibia


Reporting Checklist

  • Simple, complex, or wedge
  • Shortening or distraction
  • Presence of intercalated fragment

AO/OTA Classification

  • Similar schema for fibular fractures
  • Butterfly fragment – triangular comminuted fragment of bone that does not involve the entire circumference of the shaft
  • Ring butterfly fragment – involved entire circumference of shaft
  • Bayonet apposition – overriding fracture fragments
  • Segmental fracture – intercalated fragment with impaired vasculartity


Reporting Checklist

  • Fractures – level and pattern
  • Ligaments – lateral medial clear space
  • Weber/Lauge-Hansen – look for missed injury based on classification
  • Dislocation

Lauge-Hansen Classification of Ankle Fractures

Adapted from: Okanobo H, Khurana B, Sheehan S, Duran-Mendicuti A, Arianjam A, Ledbetter S. Simplified diagnostic algorithm for Lauge-Hansen classification of ankle injuries. Radiographics. 2012 Mar-Apr;32(2):E71-84. doi: 10.1148/rg.322115017. PMID: 22411951. and Arimoto HK, Forrester DM. Classification of ankle fractures: an algorithm. AJR Am J Roentgenol. 1980 Nov;135(5):1057-63. doi: 10.2214/ajr.135.5.1057. PMID: 6778147.

Tibial Plafond Fractures

Reporting Checklist

  • Number and location of major fragments at the level of the articular surface
  • Degree and location or articular depression
    • >2-3mm is considered significant
  • Associated tendon injury or entrapment
  • Disruption of the syndesmosis
  • Bony fragments in the syndesmosis
  • Retinaculum injury
Flexor retinaculum injury (open arrow)
Peroneal retinaculum injury

Ruedi and Allgower Classification of Pilon Fractures

Type ICleavage fracture with no major articular disruption
Type IIDisplaced fracture with minimal impaction or comminution
Type IIIDisplaced fracture with significant articular surface comminution and metaphyseal impaction


Source: Melenevsky Y, Mackey RA, Abrahams RB, Thomson NB 3rd. Talar Fractures and Dislocations: A Radiologist’s Guide to Timely Diagnosis and Classification. Radiographics. 2015 May-Jun;35(3):765-79. doi: 10.1148/rg.2015140156. PMID: 25969933.

Talar Body Fractures

Sneppen Classification of Talar Body Fractures

ACompression or osteochondral dome fracture
BCoronal shear fracture
CSagittal shear fracture
DPosterior tubercle fracture
ELateral tubercle fracture
FCrush comminuted fracture

Talar Process Fractures

Posterior Process Fracture (Shepard Fracture) – Mimics Os Trigonum

Posteromedial Tubercle Fracture (Cedell Fracture)

Lateral Process Fracture

Reporting Checklist

  • Hawkins classification
  • Degree of displacement
    • >2mm = ORIF
  • Largest fracture fragment size
    • >1cm can undergo fixation, smaller may need to be excised

Hawkins Classification of Lateral Process Fractures

Type IMost common – simple fracture with a single fracture line extending from the talofibular articulation to the subtalar joint
Type IIComminuted fracture involving the entire lateral process and both articular surfaces
Type IIIOnly involves the subtalar joint at the anterior-inferior portion of the posterior articular process

Talar Neck Fracture

Hawkins-Canale Classification of Talar Neck Fractures

TypeCharacteristicsRisk of osteonecrosis
Type INondisplaced talar neck fracture~10%
Type IITalar neck fracture and talocalcaneal dislocation~30%
Type IIITalar neck fracture, talocalcaneal dislocation, and tibiotalar dislocation>90%
Type IVTalar neck fracture, talocalcaneal dislocation, tibiotalar dislocation, talonavicular dislocation>90%

Talar Head Fractures

  • Least common fracture of the talus
  • Fracture of the articular surface of the talus at the talonavicular articulation – associated with dislocation
  • Recommend CT to evaluate for extension to talar neck, also associated with midfoot fractures
  • Hawkin sign – lucent band parallel to subchondral bone plate of talar dome due to hyperemia
    • If seen – osteonecrosis will not develop
    • 4-9 weeks after fracture
Hawkin Sign

Calcaneal Fractures

Reporting Checklist

  • Look for cortical fragments entrapped between dominant fragments – can impede reduction 
  • Extension into calcaneocuboid joint 
  • Number of sagittal fracture lines entering the posterior subtalar joint 
  • Degree of depression of articular fragments 
  • Look for peroneal retinaculum avulsion
  • Look for peroneal tendon entrapment 
  • Fragments inferior to sustentaculum tali – may entrap flexor hallicus longus tendon, tibial nerve 
  • Sanders classification

Sanders Classification of Calcaneal Fractures

Midfoot Fractures

Midfoot Sprain Injuries

Navicular Fractures

Navicular AvulsionMost common
Conservative management
Navicular Tuberosity FractureInsertion of the tibialis posterior tendonORIF
Type I Body FractureTransverse in the coronal plane No angulation of the midfoot
Type II Body FractureSagittal with dorsomedial subluxation of the talonavicular joint
Type III Body FractureComminuted fracture with lateral subluxation of the midfoot

Forefoot Fractures

Lisfranc Injury – low energy trauma

Source: Siddiqui NA, Galizia MS, Almusa E, Omar IM. Evaluation of the tarsometatarsal joint using conventional radiography, CT, and MR imaging. Radiographics. 2014 Mar-Apr;34(2):514-31. doi: 10.1148/rg.342125215. PMID: 24617695.

  • Lateral or dorsal displacement of M2 on C2 – most reliable
    • Step-off sign on lateral view
  • >2mm diastasis between M1 and M2 base on AP radiograph
  • Fleck sign

Lisfranc Fracture Dislocation – high energy trauma

  • Homolateral – all metatarsals displaced laterally
  • Divergent – M1 displaced medially, M2-M5 displaced laterally
  • Isolated – M1 displaced medially, no other metatarsals displaced
  • Don’t get bogged down with all the small fracture fragments

General Forefoot Injuries

  • If phalangeal tuft fracture – correlate for nailbed injury to exclude open fracture
    • Great toe most common
  • Jones fracture – prone to nonunion
    • Do not confuse with Os Vesalianum
  • Peroneus brevis avulsion – AKA Dancer or Pseudo-Jones Fracture
  • March/Stress Fractures – similar
  • Freiberg Disease – Osteochondrosis of the metatarsal head
    • Adolescents, F>M
  • Turf Toe – really a ligamentous injury, sometimes fracture of the sesamoids is called turf toe
  • Müeller-Weiss – osteonecrosis of the navicular in adults