Overview

Type	Location	Classification	Key Points
Femoral Head	Intracapsular	Pipkin (I–IV)	Complication of hip dislocation; I = below fovea; II = above fovea; III + neck fracture; IV + acetabular fracture
Subcapital / Femoral Neck	Intracapsular	Garden (I–IV)	AVN risk increases with grade; I = impacted valgus; II = complete nondisplaced; III = partial displaced; IV = fully displaced. <65 yrs → ORIF; >65 yrs → hemiarthroplasty or THA
Transcervical / Basicervical	Intracapsular	Descriptive	Basicervical = at base of neck, partially extracapsular; less AVN risk; treated like IT fracture
Intertrochanteric	Extracapsular	Evans-Jensen (I–IV)	Stable = intact posteromedial cortex; Unstable = posteromedial comminution, reverse obliquity, or 4-part. Treated with cephalomedullary nail or sliding hip screw
Subtrochanteric	Extracapsular	Descriptive	LT to 5 cm below; high mechanical stress (tension laterally, compression medially); requires cephalomedullary nail. Isolated LT avulsion in adults = malignancy until proven otherwise
Atypical Femoral	Subtrochanteric / shaft	ASBMR Criteria	Bisphosphonate-related; transverse, lateral cortex "beaking," medial spike, minimal comminution, periosteal thickening. Bilateral in 28–47%; image contralateral femur

Hip Dislocation — Reporting Checklist

Direction: posterior (most common, ~90%) vs anterior
Posterior: femoral head displaced superolaterally; lesser trochanter NOT visible on AP
Anterior: femoral head displaced inferomedially; obturator or ilioinguinal subtypes
Associated femoral neck fracture — closed reduction contraindicated
Associated femoral head impaction fracture (more common anteriorly → THA)
Post-reduction: assess concentricity; femoral head AVN risk (increases with delay >6 hrs)

Garden Classification — Femoral Neck

Type	Description
I	Incomplete/valgus impacted — trabecular lines not aligned; head in valgus
II	Complete, nondisplaced — trabecular lines not aligned but no displacement
III	Partial displacement — partial contact between fracture surfaces
IV	Fully displaced — no contact; trabecular lines parallel (realigned by displacement)

Garden classification: I incomplete valgus impacted; II complete nondisplaced; III partial displacement; IV fully displaced — Garden classification — femoral neck fractures

Management: <65 yrs → ORIF; >65 yrs → hemiarthroplasty or THA. AVN risk increases with grade.

Femoral Neck Reporting Checklist

Location: subcapital / transcervical / basicervical
Displaced or nondisplaced
Garden grade (higher grade = higher AVN risk)
Contralateral hip imaging if stress fracture suspected

Pauwels Classification — Fracture Line Angle

Type	Angle	Forces	Stability
I	<30°	Predominantly compressive	Stable — favorable for healing
II	30–50°	Mixed compression + shear	Intermediate
III	>50°	Predominantly shear	Unstable — high nonunion/AVN risk

Higher angle = greater shear force = increased instability and AVN risk. More predictive in younger adults.

AVN Risk

Fracture line extending through the lateral femoral head-neck junction (site of lateral epiphyseal vessel entry) carries highest AVN risk.

By location: Subcapital > transcervical > basicervical
By displacement: Displaced > nondisplaced
Posteromedial comminution and lateral head-neck extension on CT are key predictors

Femoral Neck Stress Fractures

Type	Location	Population	Management
Compression	Inferomedial neck (compression side)	Younger athletes; fatigue fracture	Conservative if nondisplaced — tends to self-reduce
Tension	Superolateral neck (tension side)	Elderly; insufficiency fracture	Surgical fixation — high risk of displacement and AVN

Pipkin Classification — Femoral Head (from hip dislocation)

Type	Description
I	Fragment inferior to fovea capitis
II	Fragment superior to fovea capitis (involves weight-bearing surface)
III	Type I or II + femoral neck fracture
IV	Type I or II + acetabular fracture

Evans Classification — Intertrochanteric

Key factor = stability, determined by posteromedial cortex integrity.

Type	Pattern	Stability
I	2-part, nondisplaced; fracture line along intertrochanteric line	Stable
II	2-part, displaced; posteromedial cortex intact	Stable
III	3-part; posteromedial cortex comminuted; greater trochanter fragment	Unstable
IV	4-part; posteromedial + greater trochanter + subtrochanteric extension	Highly unstable
Reverse	Fracture line from inferomedial to superolateral; medial displacement of shaft	Highly unstable — nail, not SHS

Evans classification of intertrochanteric fractures — stable vs unstable based on posteromedial cortex integrity — Evans classification — intertrochanteric fractures

Intertrochanteric Reporting Checklist

Posteromedial cortex: intact (stable) vs comminuted (unstable)
Greater trochanter: separate fragment?
Reverse obliquity pattern (unstable — requires nail, not SHS)
Subtrochanteric extension

Subtrochanteric Fractures

Subtrochanteric zone = lesser trochanter to 5 cm below
High-stress region: lateral cortex under tension, medial cortex under compression → requires cephalomedullary nail
Isolated lesser trochanter avulsion in adults → malignancy until proven otherwise

Russell-Taylor Classification — Subtrochanteric

Type	Piriformis Fossa	Lesser Trochanter	Implication
1A	Spared	Intact	Standard cephalomedullary nail
1B	Spared	Separate fragment	Nail; assess posteromedial cortex
2A	Involved	Intact	Reconstruction nail required (piriformis entry compromised)
2B	Involved	Separate fragment	Most complex; reconstruction nail; greatest instability

Atypical Femoral Fractures — Traumatic vs Atypical

Feature	Traumatic (High-Energy)	Atypical (Bisphosphonate)
Patient	Young, high-energy mechanism	Older; long-term bisphosphonate use (>3–5 yrs)
Fracture orientation	Comminuted, spiral, oblique	Transverse or short oblique
Lateral cortex	Variable	Periosteal thickening / "beaking" or flare
Medial spike	May be present	Characteristic medial spike
Comminution	Common	Absent or minimal
Prodrome	None	Thigh/groin pain before fracture
Bilateral	Rare	28–47% — image contralateral femur
Treatment	Cephalomedullary nail	Cephalomedullary nail; stop bisphosphonate

ASBMR criteria — key imaging features: transverse orientation, lateral cortex periosteal thickening or beaking, medial spike, minimal comminution. Bilateral in 28–47%; always image the contralateral femur.

Reference

Sheehan SE et al. Proximal Femoral Fractures: What the Orthopedic Surgeon Wants to Know. RadioGraphics. 2015;35(5):1563–84.

Proximal Femur Fractures — Garden, Pipkin, Pauwels, and Evans Classification