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Classifications

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Diabetic Foot Ulcers

SINBAD Classification

Introduced in 2008 following a multicentric study, this classification evaluates diabetic foot ulcers based on six categories.

Category	Definition	Score
Site	Forefoot	0
	Hindfoot and midfoot	1
Ischemia	Pedal blood flow intact (at least one pulse palpable)	0
	Clinical evidence of reduced pedal blood flow	1
Neuropathy	Protective sensation intact	0
	Protective sensation absent	1
Bacterial Infection	None	0
	Present	1
Area	Ulcer <1cm²	0
	Ulcer ≥1cm²	1
Depth	Ulcer confined to skin and subcutaneous tissue	0
	Ulcer reaching muscle, tendon, or deeper	1

Meggitt-Wagner Classification

Most commonly used classification for diabetic foot ulcers.

Grade	Description
0	No ulcer but foot deformity at risk of ulceration
1	Superficial ulcer
2	Deep ulcer with visible bone or tendon
3	Deep ulcer with abscess or osteomyelitis
4	Ulcer with gangrene limited to forefoot
5	Ulcer with gangrene of the whole foot

University of Texas Staging System

Second most commonly used classification, incorporating infection and ischemia.

Stage	Grade 0	Grade 1	Grade 2	Grade 3
A	Pre-/post-ulcerative lesion, epithelialized	Superficial ulcer, not involving tendon	Ulcer penetrating to tendon	Ulcer penetrating to bone/joint
B	Infection	Infection	Infection	Infection
C	Ischemia	Ischemia	Ischemia	Ischemia
D	Infection & ischemia	Infection & ischemia	Infection & ischemia	Infection & ischemia

S(AD)SAD Classification

Assesses diabetic foot based on area, depth, sepsis, arteriopathy, and denervation.

Grade	Area	Depth	Sepsis	Arteriopathy	Denervation
0	Skin intact	Skin intact	No infection	Pedal pulses present	Intact
1	Lesion <1cm²	Superficial (skin and subcutaneous tissue)	No infected lesions	Pedal pulses reduced/one missing	Reduced
2	Lesion 1–3cm²	Penetrating to tendon, periosteum, joint	Cellulitis-associated lesions	Absence of both pedal pulses	Absent
3	Lesion >3cm²	Involving bones or joint space	Lesions with osteomyelitis	Gangrene	Charcot joint

Charcot Foot: Eichenholz Classification

The Eichenholz Classification is used to stage Charcot neuroarthropathy, describing the progression of the condition through distinct radiological and clinical features.

Stage	Name	Features
0	Pre-Fragmentation	Acutely painful, regional demineralization of bone visible on imaging.
1	Fragmentation	Painful stage with peri-articular fragmentation, visible bone demineralization, and joint dislocations.
2	Coalescence	Less pain, sclerosis (bone hardening), and bone resorption as fragments coalesce.
3	Remodelling	Pain-free stage with malunited and/or ankylosed (stiffened) joints.

Osteochondral Defects of Talus: Berndt & Hardy Classification

Stage	Features
1	Subchondral fracture
2	Partially detached fragment
3	Detached but stable fragment
4	Detached and unstable fragment – free-floating

MRI Classification by Bristol Group

Stage	Definition
1	Articular cartilage injury
2a	Articular cartilage injury with underlying fracture and surrounding edema
2b	Articular cartilage injury with underlying fracture but no bony edema
3	Detached, undisplaced fragment
4	Detached, displaced fragment
5	Subchondral cyst

Occipital Condyle Fractures: Tuli Classification

Type	Features
1	Stable, undisplaced fracture
2A	Stable, displaced fracture with no ligamentous instability
2B	Unstable, displaced fracture with ligamentous instability

Atlas (C1) Fractures: Jefferson Classification

Type	Features
1	Posterior arch fracture
2	Anterior arch fracture
3	Fractures of both anterior and posterior arches
4	Lateral mass fracture

Hangman's Fracture (Traumatic C2 Spondylolisthesis): Levine & Edwards Classification

Type	Features
1	<3mm displacement, intact disc
2	>3mm displacement, disc usually intact (most common)
2a	Angulation rather than displacement, disc likely extruded
3	Concurrent facet dislocation, extruded disc, high neurologic injury

PEG Fractures: Anderson Classification

Type	Features
1	Avulsion from tip (apical or alar ligaments)
2	Waist, non-comminuted (most common)
2a	Waist, comminuted (most unstable)
3	Into cancellous bone of C2 body with/without facets involvement

Eysel Classification for Type 2 PEG Fracture

Type	Definition
A	Horizontal
B	Anteroposterior (anterosuperior to posteroinferior)
C	Reverse

Spinal Muscular Atrophy (Chromosome 5): MDA Classification

Type	Features	Name
SMA1	Onset <6 months, death <2 years	Werdnig-Hoffmann disease
SMA2	Onset by 2 years, death by 20 years	Dubowitz disease
SMA3/4	Onset after 2 years, normal lifespan	Kugelberg-Welander disease

Hereditary Sensory and Motor Neuropathy (HSMN): Charcot-Marie-Tooth Types

Type	Features	Genetic Inheritance
HSMN1/CMT1	Onset in teens, demyelination of nerves, absent reflexes, abnormal NCS	Autosomal dominant
HSMN2/CMT2	Onset >20 years, milder, no demyelination but Wallerian degeneration	Autosomal dominant
CMTX	Intermediate severity	X-linked
CMT4	Onset in infancy, severe	Autosomal recessive

Dejerine-Sottas Disease

Defined clinically with onset by 2 years of age, delayed motor milestones, and severe motor/sensory and skeletal deficits.
DSD is caused by autosomal dominant mutations in PMP22, MPZ, and EGR2
Due to its unique phenotypic features, classified as a separate group with hereditary neuropathy with liability to pressure palsies (HNPP)

Spina Bifida Types

Type	Features
Occulta	Defect in posterior elements but no extrusion
Meningocele	Extrusion of dura only
Myelomeningocele	Extrusion of neural elements contained by dura
Classic spina bifida	Neural elements extruded and fully exposed
Rachischis	Neural elements extruded and fully exposed; very severe

Capitellar Fractures: Bryan & Morrey Classification

Type	Features
1	Complete, minimal extension into trochlea (Hans Steinhal)
2	Osteochondral defect (Kocher Lorenz)
3	Comminuted compressed fracture
4	Complete with significant extension into trochlea ("double bubble")

Radial Head Fractures: Mason Classification

Type	Features
1	Undisplaced
2	Marginal fracture displaced
3	Comminuted displaced fracture
4	Fracture with elbow dislocation

Radial Neck Fractures: Mason Classification

Type	Features
1	Undisplaced
2	Displaced fracture
3	Displaced and comminuted fracture
4	Fracture with elbow dislocation

Coronoid Process: Morrey Classification

Type	Features
1	Tip
2	<50% of the coronoid
3	>50% of the coronoid

Coronoid: O’Driscoll Classification

Type	Subtype	Description
Tip	1	<2mm coronoid height
	2	>2mm coronoid height
Anteromedial	1	Rim
	2	Rim and Tip
	3	Involving sublime tubercle
Basal	1	Coronoid body and base
	2	Transolecranon basal coronoid fracture

Tibialis Posterior Insufficiency (Johnson–Myerson Grade 4)

Grade	Features
0	Asymptomatic with MRI changes
1	Tibialis posterior (TP) painful but competent
2	Incompetent TP with flexible planovalgus
3	Incompetent TP with fixed planovalgus
4	Fixed planovalgus with talar tilt

Hallux Valgus Severity

Severity	HVA	IMA
Normal	<15°	<8°
Mild	15–19°	8–13°
Moderate	20–40°	13–20°
Severe	>40°	>20°

Avascular Necrosis of the Hip (Ficat Classification)

Stage	Features
1	XR normal – MRI or Bone scan positive
2	Sclerosis and cyst formation
3	Subchondral collapse – crescent sign
4	Significant collapse and arthrosis

Avascular Necrosis of the Hip (Steinberg Classification)

Stage	Features
0	All imaging normal
1	XR normal, MRI or Bone scan positive
2	Sclerosis and cyst formation
3	Subchondral collapse – crescent sign
4	Head collapse, deformation, and flattening
5	Joint space narrowing
6	Severe arthrosis

Femoral Head Fracture Dislocations (Pipkin Classification)

Type	Features	AVN Rate
1	Dislocation with fracture inferior to fovea (non-weight-bearing zone)	<5%
2	Dislocation with fracture superior to fovea (weight-bearing zone)	<5%
3	Type 1 or 2 with associated neck fracture (worst prognosis)	50%
4	Type 1 or 2 with associated acetabular fracture	10%

Tibial Plateau (Schatzker)

Type	Features	Notes
1	Split	Young
2	Split Depression	Middle aged
3	Depression	Elderly
4	Medial plateau only	Likely knee dislocation
5	Both plateaus with metaphyseal continuity	Axial compression
6	Both plateaus with metaphyseal discontinuity	Axial compression

Stages of Elbow Instability

Stage	Features
Stage 1	Only Ulna lateral collateral ligament disrupted; Posterolateral subluxation
Stage 2	All lateral collateral ligaments disrupted; Posterolateral dislocation -- often perched; Stable on reduction
Stage 3A	Lateral and medial (xpt anterior band) collateral ligaments disrupted Stable when reduced to valgus
Stage 3B	Complete disruption of MCL including anterior band; Unstable to valgus but stable in plaster at 90 degrees
Stage 3C	Avulsion of all soft tissue from distal humerus; Unstable in plaster without flexion >90 degrees

ASIA Scale of SCI

Injury	Features
A	Complete: No sensory or motor function below level
B	Incomplete: Sensory function but no motor function below level
C	Incomplete: Motor and sensory function below level. At least 50% muscles below level have grade 2 or less power
D	Incomplete: At least 50% muscles below level have grade 3 or more power
E	Normal motor and sensory function

Glenoid Fractures

Type	Description
1A	Anterior rim
1B	Posterior rim
2	Transverse fracture exiting inferiorly
3	Transverse fracture exiting medial to coracoid
4	Transverse exiting at medial border scapula
5	Combination of 2 and 4
6	Comminuted glenoid

Calcaneal Fractures -- Sanders

Grade	Features
1	Undisplaced no matter how many fracture lines
2 (A, B, C)	1 fracture line causing 2 displaced fragments
3 (A, B, C)	2 fracture lines causing 3 displaced fragments
4	3 or more fracture lines with multiple fragments

Soft Tissue Injuries -- Tscherne

Grade	Features
0	Indirect force. Negligible soft tissue damage. No skeletal injury.
1	Low energy fracture. Superficial contusion/abrasion.
2	High energy skeletal injury. Degloving or avulsion of soft tissues. High risk of compartment syndrome.
3	Extensive crushing mechanism injury. Partial or complete amputation. Impending or established compartment syndrome.

Open Fractures -- Gustillo Anderson

Grade	Features
1	Puncture <1cm. Simple low energy fracture.
2	Laceration >1cm. Simple low energy fracture.
3a	Large or contaminated soft tissue injury. High energy fracture pattern/mechanism. Primary soft tissue coverage possible.
3b	As 3a but requires plastics for soft tissue coverage.
3c	Vascular injury.

Acetabular Fractures -- Letournel

Type	Description
Elemental	Posterior Wall
	Posterior Column
	Anterior Wall
	Anterior Column
	Transverse
Associated	Posterior Wall & Posterior Column
	Transverse and Posterior Wall
	Anterior Column and Posterior Hemitransverse
	T Type
	Both Column

Pelvic Fractures -- Tile

Grade	Features
A	Stable in all planes
B	Rotationally unstable
C	Rotationally & vertically unstable (posterior SI ligaments gone)

Pelvic Fractures -- Young & Burgess

Grade	Features
APC	Symphysis diastasis +/- SI joint widening. A&P SIJ ligaments intact.
	Ant SIJ ligament torn. Post SIJ ligament intact.
	A&P SIJ ligaments torn. Vertical displacement.
LC	Horizontal pubic ramus Fx. Sacral compression Fx. Crescent fracture.
VS	Vertically displaced hemipelvis. Symphysis and SIJ vertical displacement or vertical ramus and sacral fracture.
Combined	VS + LC, APC + VS, APC + LC

Periprosthetic Hip -- Vancouver

Type	Features
AG	Greater trochanter
AL	Lesser trochanter
B1	At level of stem or just distal to tip. Well-fixed. Good bone stock.
B2	At level of stem or just distal to tip. Loose. Good bone stock.
B3	At level of stem or just distal to tip. Loose. Loss of bone stock.
C	Distal to Stem. Stem unaffected.

Impending Pathologic Fracture -- Mirel's

Score	1	2	3
Location	Upper Limb	Lower Limb	Proximal Femur
Appearance	Sclerotic	Mixed	Lytic
Size	<1/3	<2/3	>2/3
Pain	No Pain	Moderate Pain	Unable to WB
Note	8 or more suggests impending fracture

Monteggia Fracture -- Bado

Type	Features	Notes
1	Anterior dislocation of radial head	70%
2	Posterior dislocation of radial head	5%
3	Lateral dislocation of radial head	25%
4	Associated radial shaft fracture	<5%

MESS Score

Score	0	1	2	3	4
Age	<30	30-50	>50
Shock	Systolic >90	Transient hypotension	Persistent hypotension
Limb Ischemia	Reduced Pulse. Perfused limb	Pulseless. Parasthesia. Increased CR	Insensate. Cold. Paralysed
Skeletal/Soft Tissue Injury	Low Energy	Moderate energy (open Fx)	High Energy (RTA)	Very High Energy (Crush, RTA, Contaminated)
Note	Ischaemia score doubled if ischaemia time >6 hours. Total score of 8 or more suggests limb may not be viable.

Classification of Rheumatoid Thumb - Naelbuf

Type	Deformity
Type 1	Boutonniere (MCPJ flexion) most common
Type 2	Boutonniere with CMCJ dislocation or arthritis (rare)
Type 3	Swan Neck (CMCJ adduction and flexion, MCPJ extension)
Type 4	Ulna collateral ligament laxity
Type 5	Swan Neck with no adduction of metacarpal (rare)
Type 6	Mutilating disease -- gross joint destruction

TFCC Tears -- Palmer Classification

Type 1 -- Traumatic

Type	Features
1A	Central perforation (debride)
1B	Ulna styloid avulsion
1C	Distal avulsion (triquetrum)
1D	Radial Avulsion

Type 2 -- Degenerative

Type	Features
2A	Thinning of TFCC but no perforation
2B-E	Progressive arthrosis affecting carpal joints and DRUJ

Scaphoid Fractures

Russe -- Pattern

Pattern	Description
Transverse
Horizontal Oblique
Vertical Oblique	Most unstable

Stability -- Herbert

Stability	Features
Stable	<1mm displacement
Unstable	>1mm displacement or gap, >60 degrees scapholunate angle, >15 degrees Radio-lunate angle, Comminution, Proximal Pole, Vertical Oblique fracture pattern

Anatomic Location

Location
Proximal Pole
Waist
Distal Pole
Tuberosity

Keinbock's Disease -- Lichtman

Stage	Features	Management
1	XR Normal. MRI low signal	Non-operative surveillance
2	Sclerotic Lunate. No collapse or fragmentation	Joint Levelling, Core Decompression, Vascularised Grafting
3A	Lunate collapse. No Instability. Scaphoid not rotated or fixed	Joint Levelling, Core Decompression, Vascularised Grafting (less predictable than stage 2), Limited Fusion
3B	Lunate Collapse. Reduced Carpal height. Instability -- scaphoid in fixed rotation	Limited Fusion, PRC
4	Pancarpal Arthrosis	Wrist Fusion, PRC (not if capitate affected)

Classification of SLAP Tears -- Schneider

Type	Description	Management
Type 1	Fraying of superior labrum, intact biceps anchor	Debride
Type 2	Unstable Biceps Anchor	Re-attach
Type 3	Bucket handle detachment of superior labrum from intact biceps anchor	Debride
Type 4	Bucket handle detachment of whole biceps anchor with propagation into LHB tendon	Re-attach +/- LHB tenotomy
Type 5	SLAP with Labral tear	Reattach both
Type 6	Superior flap tear	Debride
Type 7	SLAP with capsular tear	Fix and reattach

Rheumatoid Arthritis Elbow -- Larsen

Grade	Features
1	Soft tissue inflammation & periarticular osteoporosis
2	Joint space narrowing
3	Significant joint space narrowing
4	Subchondral bony erosion and arthrosis
5	Severe arthritis with deformity

Thumb CMCJ Arthritis -- Eaton

Stage	Features
Stage 1	Joint space widened, <1/3 subluxation
Stage 2	Decreased joint space, Marginal Osteophytes <2mm, 1/3 joint subluxation
Stage 3	Significant arthrosis, Sclerosis and cysts, Osteophytes >2mm, >1/3 subluxation
Stage 4	STT arthritis

Hallux Rigidus -- Coughlin

Grade	X-Ray	Pain	MTPJ Motion
0	Normal	None	Minimal stiffness
1	Minimal narrowing	Intermittent	Mild restriction
2	Narrowing & Osteophytes	Almost constant	Moderate restriction
3	Severe arthrosis	Constant	None at mid range (<20 degrees)
4	Severe arthrosis	Pain at mid range	<20 degrees

AVN Humeral Head -- Creuss

Stage	Features
1	XR Normal, MRI abnormal
2	Sclerosis on XR
3	Subchondral Collapse ('Crescent sign')
4	Humeral head collapse, Glenoid normal
5	Humeral head and Glenoid Arthrosis & Erosion

Classification of Cerebral Palsy

Type

Type	Features
Spastic	UMN symptoms predominate
Athetoid	Flaccidity -- rare
Ataxic	Cerebellar symptoms predominate

Geographic

Type	Features
Quadriplegic	Whole body involvement
Diplegic	Lower limbs only
Hemiplegic	Unilateral involvement -- rare

Gross Motor Function Classification System (GMFCS)

Type	Features
GMFCS 1	Able to walk independently
GMFCS 2	Occasional difficulty walking on slopes or in crowds
GMFCS 3	Requires a walking aid. Can self propel a wheelchair
GMFCS 4	Can transfer only. Supports own head in wheelchair
GMFCS 5	Wheelchair bound. Unable to support head

Perthes Disease -- Herring Lateral Pillar Height

Stage	Lateral Pillar Height
A	Normal
B	>50%
B/C	50% with narrowing of physis
C	<50%

Cervical Spine Rheumatoid Arthritis Severity -- Ranawat

Stage	Features
1	No neurologic findings -- pain only
2	Subjective neurology
3a	Objective neurology & UMN signs -- patient ambulatory
3b	Objective neurology & UMN signs -- patient not ambulatory

3b do poorly with surgery -- identify and operate earlier.

Ferguson Mechanistic Classification of Sub-Axial Fractures

Type	Examples	Notes
Flexion Compression	Flexion tear drop	High rate neuro injury. Surgical management
Flexion Distraction	Facet Dislocation	High Rate neuro injury. Surgical management
Axial	Burst Fracture	Management depends on features of instability and neurology
Extension Compression	Isolated posterior element fractures	Low incidence neuro injury. Highly unstable though - surgery
Extension Lateral	Compression	Beware: associated plexus injury

Spondylolisthesis

Myerding -- Degree Slip

Grade	Features
Grade 1	0 -25%
Grade 2	25-50%
Grade 3	50-75%
Grade 4	75-100%
Grade 5	>100% (spondyloptosis)

Wiltse -- Type

Type	Features
1 (Dysplastic)	L5/S1, Intact neural arch, max 30% slip, L5 inferior facet poorly formed, S1 superior facet absent, Trapezoidal L5. Girls & Eskimo's
2 (Isthmic)	Stress fracture pars, Elongated Pars, Acute Fracture Pars. Boys & Eskimo's. Sagittally oriented facets -- not dysplastic, <25% slip usually
3 (Degenerative)	Women, Diabetic, Black, >40 years, L4/5
4 (Traumatic)
5 (Pathologic)
6 (Iatrogenic)

Nerve Injury -- Seddon and Sunderland

Type	Features	Sunderland Grade	Prognosis
Neuropraxia	No Wallerian Degeneration, segmental demyelination, conduction block, epineurial damage	Grade 1	Good
Axonotmesis	Wallerian degeneration distal to injury, axonal damage, conduit for regeneration intact	Grade 2-4	Okay
Neurotmesis	Wallerian degeneration beyond injury, endoneurium violated, no conduit for regeneration	Grade 5	Poor

Sacral Fractures -- Denis

Type	Features	Notes
Zone 1	Lateral to foramina	50% of fractures; 5% neurologic injury
Zone 2	Through the foramina	30% of fractures; 30% neurologic injury
Zone 3	Medial to foramina	20% of fractures; 60% neurologic injury

Femoral Head Fracture Dislocation -- Pipkin

Type	Features	AVN Rate
1	Dislocation with fracture inferior to fovea (NWB zone)	<5%
2	Dislocation with fracture superior to fovea (WB zone)	<5%
3	Type 1 or 2 with associated neck fracture (worst)	50%
4	Type 1 or 2 with associated acetabular fracture	10%

Bone Tumors -- Enneking

Type	Grade	Intra/Extra Compartmental	Metastases
1A	Low	Intra	None
1B	Low	Extra	None
2A	High	Intra	None
2B	High	Extra	None
3A	Any	Intra	Mets
3B	Any	Extra	Mets

SUFE Severity -- Southwick Angle

Severity	Features
Mild	<30 degrees
Moderate	30-50 degrees
Severe	>50 degrees

Talar Neck Fractures -- Hawkins

Type	Features	AVN	Non-Union	STJ OA
1	Undisplaced	10%	2%	25%
2	Displaced with STJ subluxation	50%	8%	65%
3	Displaced with STJ & Ankle subluxation	90%	10%	70%
4	Displaced with STJ, TTJ & TNJ subluxation	100%	20%	90%

Discoid Meniscus

Type	Features
Incomplete	Partial coverage
Complete	Full coverage
Wrisberg Variant	Only attachment is meniscofemoral ligaments

Meniscal Tears -- Tear Pattern

Pattern	Subtypes	Features
Vertical	Longitudinal (Bucket Handle)	Bucket handles propagate longitudinally
Horizontal	Full or Partial Cleavage	Flap tears most common
Complex	Combinations of above patterns

Adult Hip Dysplasia -- Crowe

Type	Features
1	<50% migration
2	50-75% migration
3	75-100% migration
4	>100% migration

Classification of Tibial Bone Defects in TKR

Type	Features	Management
1	<1 cm focal defect, cortical rim intact	Fill with cement
2	Contained defect, cortical rim intact	Cancellous autograft and cement
3	Uncontained defect, no cortical rim intact	Metallic augments, allograft, revision stems

Knee Dislocation - Schenk

Stage	Features
KD1	ACL or PCL (very rare)
KD2	ACL & PCL only
KD3M	ACL, PCL & MCL
KD3L	ACL, PCL & LCL
KD4	ACL, PCL, MCL, LCL
KD5	Fracture Dislocation

Clavicle Fractures -- Neer

Type	Features
Type 1	Middle 1/3
Type 2	Distal 1/3
Type 3	Proximal 1/3
2a	Minimally displaced
2b	Displaced -- fracture medial to CC ligaments
2c	Intra-articular -- both CC ligaments tend to be torn
2d	Paediatric periosteal sleeve avulsion
2e	Comminuted
3a-e	Same system as for type 2 fractures

Graf Classification of DDH

Type	Alpha angle	Features
1	>60 degrees	Normal enlocated hip
2	43-60 degrees	Borderline group, may or may not be abnormal
3	<43 degrees & labrum everted	Hip subluxated
4	<43 degrees & labrum interposed	Hip dislocated

Denis -- 3 Column Theory of Spinal Stability

Fracture Type	Columns Affected
Compression	Anterior column only
Flexion Distraction	Middle and Posterior tension failure, Anterior column intact as a hinge
Burst	Anterior & Middle column co mpression failure
Fracture Dislocation	All three columns disrupted
Anterior Column	ALL, Anterior 2/3 vertebral body and disc
Middle Column	Posterior 1/3 vertebral body and disc, PLL
Posterior Column	Neural arches

Swanson's Classification of Congenital Anomalies

Type	Examples
Failure of Formation	Transverse or longitudinal arrest, Pre or post axial, Amelia, Radial or Ulna club Hand
Failure of Differentiation	Bony or Soft tissue, Syndactyly, Camptodactyly, Clinodactyly, Duplication, Pre or post axial, Polydactyly, Thumb duplication
Overgrowth	Hyperplasia
Undergrowth	Hypoplasia
Constriction Bands	Generalised syndromes, Madelung's

Wassel's Classification of Thumb Duplications

Type	Features
1	Bifid P3
2	Duplicated P3
3	Bifid P2
4	Duplicated P2 (most common)
5	Bifid P1
6	Duplicated P1
7	Triphalangism

Classification of Articular Cartilage Degeneration (Jackson)

Grade	Features
1	Softening
2	Fibrillation and fissuring
3	Partial thickness defects with flaps and clefts
4	Full Thickness defects with exposed subchodral bone

Lauge Hansen Classification of Ankle Fractures

Mechanism	Features
Supination External Rotation	AITFL or Chaput fragment, Oblique Weber B Fibula Fracture in a posterior superior to anterior inferior direction, PITFL or Posterior Malleolus Fracture, Medial Malleolar T ransverse Fracture
Supination Adduction	T ransverse Weber A fibula fracture, Vertical Medial Malleolar Fracture
Pronation External Rotation	Medial Malleolus Fracture, AITFL or Chaput, Oblique/spiral Weber C fracture in anterior superior to posterior inferior direction, PITFL or Posterior Malleolus Fracture
Pronation Abduction	T ransverse Medial Malleolar Fracture, AITFL, PITFL or Chaput, Simple or Butterfly Weber C (bending injury)

Paprosky Classification of Femoral Defects

Type	Features
1	Minimal Metaphyseal bone loss, Normal Diaphyseal bone stock
2	Moderate Metaphyseal bone loss, Normal Diaphyseal bone stock
3a	Significant metaphyseal bone loss, Diaphyseal bone loss with >4cm isthmus for fixation
3b	Significant metaphyseal bone loss, Diaphyseal bone loss with <4cm isthmus for fixation
4	Inadequate diaphyseal bone for long stem fixation

Paprosky Classification of Acetabular Defects

Type	Features
1	Minimal Bone loss; Minimal migration; Fully stable cup
2a	Superior migration, Superior Bone loss, Stable cup, Rest of Acetabulum ok
2b	Superior migration, Uncontained superior bone defect, >50% bone contact, Stable cup
2c	Medial migration past kohler's line, Uncontained medial defect, Stable cup, >50% contact
3a	Superior migration, Moderate ischial, teardrop lysis, No significant medial migration, Partial stability of cup, 40% contact
3b	Large uncontained defects, Significantly migrated cup -- superior or medial to kohler's line, Bone contact <40%, Risk of pelvic discontinuity, Unstable cup

Related FRCS revision notes

Useful Tables Diabetic Foot (Foot and Ankle)Surgical Site Infection Basic Biology Antibiotics and infection Osteoporosis

Linked from

← Classifications and tables ← Useful Tables ← Osteoarthritis classifications

Written/reviewed by Kishore Puthezhath

Professor of Orthopaedics and Consultant Paediatric Orthopaedic Surgeon

FRCS (Tr & Orth) revision resource

Reviewed: September 2026

Core revision references: Miller's Review of Orthopaedics; Campbell's Operative Orthopaedics; Orthobullets. Current specialty guidelines are linked within individual notes where applicable.