Fracture Radiology & Bone Injuries

Fracture identification on plain radiographs is one of the highest-yield, most reliably scoring areas in NEET PG. Eponymous fractures, the Salter-Harris growth-plate system, and the recognition of periosteal reactions recur in almost every paper. This note builds a systematic radiological eye and locks down the named patterns examiners love.

How to describe a fracture (the examiner's checklist)

A complete radiological description follows a fixed order. Memorise it — single-best-answer questions are often disguised descriptions:

1. Bone & side (right/left, which bone)
2. Site — epiphysis / metaphysis / diaphysis; proximal, middle, distal third
3. Pattern — transverse, oblique, spiral, comminuted, segmental, greenstick, buckle (torus)
4. Displacement — translation, angulation, rotation, shortening (described by the distal fragment relative to proximal)
5. Articular involvement — intra- vs extra-articular
6. Open vs closed — soft tissue gas, foreign body
7. Special features — avulsion, impaction, pathological, stress

High-yield: Displacement, angulation and rotation are always described in terms of the distal fragment. This single rule answers many "describe the deformity" MCQs.

Fracture pattern primer

Pattern	Mechanism	Classic look on X-ray
Transverse	Direct/tapping force, bending	Line perpendicular to long axis
Oblique	Angulated force	Diagonal line >30°
Spiral	Torsion/rotation	Corkscrew; ends taper — suspect NAI in toddlers
Comminuted	High energy	>2 fragments
Segmental	Two-level	Free intermediate segment
Greenstick	Bending (children)	Cortex broken one side, intact other
Torus/buckle	Axial load (children)	Cortical bulge, no cortical break
Avulsion	Tendon/ligament pull	Bony fleck at insertion

Eponymous fractures of the upper limb

These are the bread-and-butter of orthopaedic radiology MCQs.

Distal radius: Colles vs Smith vs Barton

Colles fracture — fracture of the distal radius (within ~2.5 cm of the wrist joint) with dorsal displacement and angulation of the distal fragment. Mechanism: fall on an out-stretched dorsiflexed hand (FOOSH). Classic clinical sign: "dinner-fork" deformity. Commonest in postmenopausal osteoporotic women. Often associated with avulsion of the ulnar styloid.

Smith fracture ("reverse Colles") — distal radius fracture with volar (palmar) displacement. Mechanism: fall on the back of a flexed hand. Deformity: "garden-spade".

Barton fracture — an intra-articular distal radius fracture with dislocation/subluxation of the radiocarpal joint. Dorsal Barton (commoner) vs volar Barton. The articular involvement distinguishes it from Colles/Smith.

Chauffeur (Hutchinson) fracture — intra-articular fracture of the radial styloid.

High-yield: Colles = dorsal (dinner-fork), Smith = volar (garden-spade), Barton = intra-articular with carpal dislocation. The fastest discriminator on radiograph is the direction of distal-fragment displacement on the lateral view.

Fracture	Bone/site	Displacement	Mechanism	Deformity
Colles	Distal radius (extra-artic.)	Dorsal	FOOSH, extended wrist	Dinner-fork
Smith	Distal radius (extra-artic.)	Volar	Fall on flexed wrist	Garden-spade
Barton	Distal radius (intra-artic.)	Dorsal/volar + carpal dislocation	FOOSH	—
Chauffeur	Radial styloid (intra-artic.)	—	Direct/avulsion	—

Forearm fracture-dislocations: Monteggia vs Galeazzi

This pair is endlessly tested. Use the mnemonic MUGR:

Monteggia = Ulna fracture + radial head (proximal radio-ulnar) dislocation. Galeazzi = Radius fracture + distal radio-ulnar joint (DRUJ) dislocation.

Alternative aid: GRIMUS — Galeazzi = Radius, Inferior (distal); Monteggia = Ulna, Superior (proximal).

• Monteggia: fracture of the proximal third of the ulna with dislocation of the radial head. Always trace a line through the radial shaft and head — on every view it must point to the capitellum (the radiocapitellar line); if it misses, the radial head is dislocated. Bado classification (I–IV) by direction of radial head dislocation; Type I (anterior) is commonest.
• Galeazzi: fracture of the distal third of the radius with dislocation of the DRUJ. "Fracture of necessity" in adults (needs ORIF).

High-yield: In any single-bone forearm fracture, look hard for a dislocation at the other end — an isolated ulnar or radial shaft fracture without dislocation is uncommon because the forearm is a "ring".

Other named upper-limb fractures

• Bennett fracture — intra-articular fracture-dislocation of the base of the first metacarpal (thumb). A small volar-ulnar fragment stays attached to the trapezium while the metacarpal shaft is pulled proximally/radially by abductor pollicis longus. Rolando fracture = comminuted (T- or Y-shaped) intra-articular base of thumb metacarpal — worse prognosis than Bennett.
• Boxer's fracture — fracture of the neck of the 5th metacarpal from punching.
• Scaphoid fracture — FOOSH with anatomical-snuffbox tenderness; risk of avascular necrosis of the proximal pole and non-union because the blood supply enters distally (retrograde flow). May be invisible initially — repeat film at 10–14 days or MRI.
• Holstein-Lewis fracture — spiral fracture of the distal third of the humerus with radial nerve entrapment/palsy.

Lower limb & pelvis named injuries

• Pott's fracture — bimalleolar ankle fracture-dislocation.
• Maisonneuve fracture — proximal fibular fracture with syndesmotic injury + medial malleolus/deltoid ligament injury; always image the proximal fibula in ankle injuries.
• Jones fracture — fracture at the base of the 5th metatarsal (metaphyseal-diaphyseal junction, ~1.5 cm distal to tuberosity); prone to non-union (watershed zone). Distinguish from a pseudo-Jones / dancer's avulsion of the tuberosity itself (better prognosis).
• Segond fracture — avulsion fracture of the lateral tibial plateau; highly associated with ACL tear and meniscal injury.
• Tillaux fracture — Salter-Harris III of the anterolateral distal tibial epiphysis in adolescents.
• March fracture — stress fracture of the metatarsal (classically 2nd) in soldiers/runners.

Salter-Harris classification (physeal/growth-plate injuries)

Applies only to children — injuries involving the epiphyseal growth plate (physis). The single most repeated paediatric-orthopaedics MCQ. Mnemonic SALTR:

Type	Mnemonic	Anatomy of fracture line	Notes
I	S = Slip / Separated	Through physis only	Epiphysis separates; e.g. SCFE; often normal X-ray
II	A = Above	Physis + metaphysis (spares epiphysis)	Commonest (~75%); metaphyseal Thurston-Holland fragment
III	L = Lower	Physis + epiphysis (into joint)	Intra-articular
IV	T = Through / Together	Metaphysis + physis + epiphysis	Intra-articular; high risk of growth arrest
V	R = Rammed / cRush	Crush of physis	Worst prognosis; often diagnosed retrospectively

Stepwise reasoning for a paediatric physeal injury: Is the physis involved? → Does the line go up into metaphysis (II), down into epiphysis (III), or through both (IV)? → Any crush with no line but later growth arrest (V)?

High-yield: Type II is the commonest; Types IV and V carry the highest risk of premature growth arrest and limb deformity. Higher number ⇒ worse prognosis (with V worst).

High-yield: A Thurston-Holland fragment (triangular metaphyseal fragment) signifies Salter-Harris type II.

Stress fractures

• Fatigue fracture — abnormal repetitive stress on normal bone (runners, soldiers, dancers). Examples: march (metatarsal), tibial shaft, femoral neck, calcaneus, pars interarticularis (spondylolysis).
• Insufficiency fracture — normal stress on abnormal/weak bone (osteoporosis, osteomalacia, Paget, post-radiation). Classic: sacral insufficiency fracture (H-shaped/"Honda sign" uptake on bone scan).

Radiology: early X-ray is often normal; later shows a lucent line, sclerosis, or fluffy periosteal callus. MRI is the most sensitive early test (marrow oedema); bone scan also sensitive but less specific.

High-yield: Fatigue = abnormal stress + normal bone; Insufficiency = normal stress + abnormal bone. MRI is the investigation of choice for early stress fractures.

Pathological fractures

A fracture through bone weakened by an underlying lesion, occurring with trivial or no trauma.

Common causes (mnemonic for lytic bony metastases — "Lead Kettle" = PB-KTL): Prostate (often blastic), Breast, Kidney, Thyroid, Lung. Other causes: multiple myeloma (commonest primary marrow malignancy causing fractures, "punched-out" lytic lesions), simple/aneurysmal bone cysts, giant cell tumour, enchondroma, fibrous dysplasia, osteoporosis.

Radiological clues to a pathological/aggressive lesion: wide zone of transition, cortical destruction, soft-tissue mass, aggressive periosteal reaction, fracture through a lytic area. Vertebral pathological collapse with pedicle erosion (winking owl sign) suggests metastasis.

Periosteal reactions

The periosteal response reflects how fast and aggressively a lesion grows — a favourite "match the X-ray" question.

Pattern	Appearance	Implication	Classic associations
Solid/continuous	Uniform thick new bone	Benign / slow	Osteoid osteoma, healing fracture, osteomyelitis (chronic)
Lamellated ("onion-skin")	Concentric layers	Intermediate–aggressive	Ewing sarcoma, osteomyelitis
Spiculated "sunburst/sunray"	Radiating spicules ⊥ cortex	Aggressive	Osteosarcoma
Codman triangle	Elevated periosteum at lesion margin	Aggressive	Osteosarcoma, Ewing, subperiosteal abscess

High-yield: Sunburst/sunray + Codman triangle at the metaphysis of the distal femur/proximal tibia in a teenager = osteosarcoma. Onion-skin lamellation in the diaphysis of a child = Ewing sarcoma.

Specific recognition signs (named radiological signs)

• Fat-pad / sail sign (elbow): anterior (sail) and/or posterior fat-pad elevation indicates a joint effusion (haemarthrosis) ⇒ occult fracture — radial head in adults, supracondylar in children.
• Fat-fluid level (lipohaemarthrosis): horizontal beam shows fat-fluid level in a joint ⇒ intra-articular fracture (commonly knee — tibial plateau).
• Posterior fat pad at elbow is always pathological (anterior may be normal).
• Anterior humeral line must pass through the middle third of the capitellum — disruption suggests supracondylar fracture.
• Fabella, sesamoids and accessory ossicles are normal — do not call them fractures (smooth, corticated margins).

Diagnosis & investigation of choice

• Plain radiograph (X-ray), two orthogonal views (AP + lateral) — first-line and usually sufficient. "One view is no view."
• Always include the joint above and below a long-bone fracture (to catch Monteggia/Galeazzi).
• CT — best for complex/intra-articular fractures (tibial plateau, calcaneus, acetabulum, spine), surgical planning, and occult fractures.
• MRI — best for occult fractures (scaphoid, hip), stress fractures, marrow involvement, soft-tissue & ligament injuries, and assessing tumour extent.
• Bone scan — sensitive but non-specific; useful in stress/insufficiency fractures and metastatic screening.

Management/principles (orthopaedic radiology context)

General sequence: Reduce → Hold (immobilise) → Rehabilitate, after analgesia and neurovascular assessment.

• Colles: closed reduction + below-elbow cast (forearm pronated, wrist flexed-ulnar deviated); ORIF if unstable/intra-articular.
• Galeazzi: "fracture of necessity" — ORIF of radius + reduce DRUJ in adults.
• Monteggia: ORIF of ulna usually reduces radial head (children: closed; adults: open).
• Bennett: reduction + K-wire/screw fixation (unstable due to APL pull).
• Scaphoid: suspected fracture with normal X-ray ⇒ immobilise in thumb spica and re-image / MRI; displaced ⇒ screw fixation.
• Salter-Harris I/II: usually closed reduction; III/IV: anatomical (often open) reduction to restore the articular surface and physis.

Complications

• Early: haemorrhage/shock, compartment syndrome, vascular/nerve injury, fat embolism (long-bone, esp. femur), infection (open fractures).
• Late: malunion, delayed union, non-union (classic in scaphoid, femoral neck, Jones, lateral tibial), avascular necrosis (scaphoid proximal pole, femoral head, talus), Volkmann's ischaemic contracture (supracondylar humerus), growth arrest (Salter-Harris IV/V), myositis ossificans, complex regional pain syndrome (Sudeck atrophy), post-traumatic osteoarthritis.

High-yield: Sites notorious for AVN/non-union share retrograde blood supply: scaphoid proximal pole, femoral head (intracapsular neck fracture), talus, Jones fracture.

Key differentials / mimics

• Accessory ossicles & growth plates vs fracture: ossicles have smooth corticated margins, physes are bilateral/symmetrical — compare with the other side.
• Non-accidental injury (NAI) in children: multiple fractures of different ages, posterior rib fractures, metaphyseal corner/bucket-handle fractures, spiral fractures in non-ambulant infants.
• Pathological fracture vs simple fracture: look for an underlying lytic/blastic lesion and disproportionate trauma.
• Bone tumour mimics: osteomyelitis can mimic Ewing (both onion-skin); osteoid osteoma vs stress fracture (nidus + nocturnal pain relieved by NSAIDs).

Recently asked / exam angle

• Match the eponym: Colles = dorsal, Smith = volar, Barton = intra-articular — repeatedly tested on lateral-view image-based questions.
• MUGR / Galeazzi vs Monteggia image identification (which bone is fractured + which joint dislocated).
• Salter-Harris: identify the type from a labelled diagram; "commonest type" (II); "worst prognosis" (V); meaning of Thurston-Holland fragment.
• Periosteal reaction matching: sunburst + Codman ⇒ osteosarcoma; onion-skin ⇒ Ewing.
• Sail/fat-pad sign ⇒ occult radial head (adult) / supracondylar (child) fracture.
• Segond fracture ⇒ ACL injury association.
• Jones fracture site and non-union risk; March fracture in recruits.
• Fatigue vs insufficiency fracture definitions; MRI as the most sensitive early modality.
• Investigation of choice questions: scaphoid occult fracture ⇒ MRI; intra-articular calcaneal/tibial plateau ⇒ CT.
• Holstein-Lewis fracture ⇒ radial nerve palsy.

Rapid revision

1. Describe displacement/angulation/rotation by the distal fragment.
2. Colles = dorsal displacement, dinner-fork, FOOSH; Smith = volar, garden-spade.
3. Barton = intra-articular distal radius + radiocarpal dislocation; Chauffeur = radial styloid.
4. MUGR: Monteggia = Ulna fracture + proximal radial-head dislocation; Galeazzi = Radius fracture + DRUJ dislocation.
5. Bennett = intra-articular base of 1st metacarpal (APL pull); Rolando = comminuted version.
6. Scaphoid fracture ⇒ snuffbox tenderness, proximal-pole AVN, MRI if X-ray normal.
7. Salter-Harris II is commonest; V worst; Thurston-Holland fragment = type II.
8. Sunburst + Codman triangle ⇒ osteosarcoma; onion-skin ⇒ Ewing sarcoma.
9. Sail / fat-pad sign ⇒ occult elbow fracture (radial head adult, supracondylar child); posterior fat pad is always abnormal.
10. Segond ⇒ ACL tear; Maisonneuve ⇒ check proximal fibula in ankle injury.
11. Jones (5th metatarsal base) and scaphoid/femoral neck/talus = high non-union/AVN risk.
12. Fatigue fracture = abnormal stress on normal bone; insufficiency = normal stress on weak bone; MRI most sensitive early.