Femoral Head Fractures

High-yield overview

Pipkin Classification | Associated Hip Dislocation | AVN Risk

6 hoursTarget for dislocation reduction

10-40%AVN rate depending on Pipkin type

75-90%Associated with posterior hip dislocation

Type IVPipkin with acetabular fracture - worst prognosis

PIPKIN CLASSIFICATION

Type I

PatternFragment BELOW fovea (non-weight-bearing)

TreatmentExcise if small, fix if large

Type II

PatternFragment ABOVE fovea (weight-bearing)

TreatmentORIF required

Type III

PatternType I or II + femoral neck fracture

TreatmentArthroplasty (elderly) or fix neck + head

Type IV

PatternType I or II + acetabular fracture

TreatmentFix acetabulum + address head

Critical Must-Knows

Pipkin I = BELOW fovea (non-weight-bearing) - may excise if small fragment
Pipkin II = ABOVE fovea (weight-bearing) - MUST fix or excise
Pipkin III = associated femoral neck fracture - high AVN risk, often arthroplasty
Reduce dislocation URGENTLY - every hour increases AVN risk

Clinical Pearls

"
Fovea is the KEY landmark - above vs below determines treatment
"
Posterior dislocation = anterior approach for ORIF (avoid posterior blood supply)
"
CT scan ESSENTIAL after reduction - assess fragment size and location
"
Time to reduction is the most important prognostic factor

Clinical Imaging

Imaging Gallery

Entire treatment course of a Pipkin type IV femoral head fracture in a patient with posterior hip dislocation status post motor vehicle collision. Initial AP pelvic radiograph (a) with posterior super — Entire treatment course of a Pipkin type IV femoral head fracture in a patient with posterior hip dislocation status post motor vehicle collision. IniCredit: Wong PK et al. via Int J Emerg Med via Open-i (NIH) (Open Access (CC BY))

Pipkin Type I femoral head fracture with ORIF and 3-year follow-up — Pipkin Type I Femoral Head Fracture. (a) Pre-op AP showing posterior hip dislocation with infrafoveal head fragment. (b) Post-reduction radiograph. (c,d) 3-year follow-up AP and lateral showing excellent outcome after ORIF of fragment below fovea (non-weight-bearing zone).Credit: Shakya et al., BMC Musculoskelet Disord 2023, PMC10116746, CC BY 4.0

Pipkin Type II femoral head fracture with Herbert screw fixation and 7-year follow-up — Pipkin Type II Femoral Head Fracture with Herbert Screw Fixation. (a) Pre-op showing suprafoveal (weight-bearing) fragment. (b) Post-op with Herbert screw. (c) 4-year follow-up. (d) 7-year follow-up showing progression to post-traumatic OA. ORIF is mandatory for Type II as fragment is in weight-bearing zone.Credit: Shakya et al., BMC Musculoskelet Disord 2023, PMC10116746, CC BY 4.0

Pipkin Type III showing CT imaging and combined fixation approach — Pipkin Type III Femoral Head + Neck Fracture. (a) Coronal CT showing femoral head fragment with ipsilateral femoral neck fracture. (b) 3D CT reconstruction for surgical planning. (c) Post-operative AP with Herbert screws for head + cannulated screws for neck via combined approach. Consider THA in elderly due to high AVN risk.Credit: Shakya et al., BMC Musculoskelet Disord 2023, PMC10116746, CC BY 4.0

Time is Femoral Head!

URGENT Reduction Priority

Reduce hip dislocation within 6 HOURS. AVN risk increases exponentially with time. Reduce in ED if possible, OR if not. Do NOT delay for elaborate imaging.

Post-Reduction CT

After concentric reduction confirmed on XR. CT defines fragment size and location. Assess for loose bodies in joint. Plan surgical approach and fixation.

At a Glance

Femoral head fractures (Pipkin classification) occur with posterior hip dislocations and are orthopedic emergencies. URGENT reduction within 6 hours is critical - AVN risk increases exponentially with delay. Pipkin I (fragment inferior to fovea) can often be excised. Pipkin II (fragment involves weightbearing dome) requires ORIF. Pipkin III (with femoral neck fracture) often needs arthroplasty due to high AVN risk. Pipkin IV (with acetabular fracture) requires addressing both injuries. Post-reduction CT scan is ESSENTIAL to assess fragment size and location. Time to reduction is the most important prognostic factor.

Femoral Head Fracture - Pipkin Management Guide

Pipkin Type	Fragment Location	Management
Type I - small fragment	Below fovea (non-weight-bearing)	Excise fragment, remove loose bodies
Type I - large fragment	Below fovea but over 20% surface	Consider ORIF with countersunk screws
Type II	Above fovea (weight-bearing)	ORIF REQUIRED - countersunk screws
Type III - young patient	Any + femoral neck fracture	Fix neck urgently + address head
Type III - elderly patient	Any + femoral neck fracture	Total hip arthroplasty
Type IV	Any + acetabular fracture	Fix acetabulum through posterior + anterior approach for head
Irreducible dislocation	Interposed fragment	Emergent open reduction
Delayed presentation over 6 hours	Any type	Still reduce urgently, accept higher AVN risk

Mnemonic

PIPKINPIPKIN for Classification

P	Position relative to fovea	K	Knocked neck (Type III - femoral neck fracture)
I	Inferior (Type I - below fovea)	I	Injury to acetabulum (Type IV)
P	Proximal (Type II - above fovea)	N	Need urgent reduction regardless

P	Position relative to fovea	P	Proximal (Type II - above fovea)	I	Injury to acetabulum (Type IV)
I	Inferior (Type I - below fovea)	K	Knocked neck (Type III - femoral neck fracture)	N	Need urgent reduction regardless

Hook:PIPKIN: I below, II above - just remember 'I is Inferior, II is Superior to fovea'!

Mnemonic

FOVEAFOVEA for Management

F	Fragment above = Fix it (Type II)
O	Observe for small fragments below fovea
V	Very urgent reduction (under 6 hours)
E	Excise small non-weight-bearing fragments
A	Approach: anterior for posterior dislocation

F	Fragment above = Fix it (Type II)	E	Excise small non-weight-bearing fragments
O	Observe for small fragments below fovea	A	Approach: anterior for posterior dislocation
V	Very urgent reduction (under 6 hours)

Hook:The FOVEA is your landmark - above it means weight-bearing!

Mnemonic

TIMEAVN Risk Factors

T	Time to reduction (most important)
I	Initial displacement severity
M	Multiple reduction attempts
E	Extended dislocation (over 6 hours)

T	Time to reduction (most important)	M	Multiple reduction attempts
I	Initial displacement severity	E	Extended dislocation (over 6 hours)

Hook:TIME is the enemy of the femoral head blood supply!

Mnemonic

SIXSIX for Reduction Time

S	Six hours is the target
I	Increasing AVN after six hours
X	eXpedite reduction urgently

S	Six hours is the target
I	Increasing AVN after six hours
X	eXpedite reduction urgently

Hook:SIX hours - reduce by six or pay the price!

Overview

Femoral head fractures are uncommon injuries that almost exclusively occur in association with traumatic hip dislocation, most commonly posterior. First classified by Pipkin in 1957, these fractures result from high-energy trauma where the femoral head impacts against the acetabular rim during dislocation.

The critical determinant of outcome is the time from injury to reduction. Prolonged dislocation leads to stretching and occlusion of the medial femoral circumflex artery (MFCA), the primary blood supply to the femoral head. Avascular necrosis (AVN) rates increase dramatically after 6 hours of dislocation.

The Pipkin classification guides management by distinguishing between fragments involving the weight-bearing (superior to fovea - Type II) and non-weight-bearing (inferior to fovea - Type I) portions of the femoral head. Types III and IV represent more complex injuries with associated femoral neck and acetabular fractures respectively.

For the orthopaedic examination, you must know the Pipkin classification, understand the urgency of reduction, and be able to discuss surgical approaches and indications.

Anatomy

Anatomy and Blood Supply

Femoral Head Anatomy

Weight-Bearing Dome:

Superior aspect of femoral head
Covered by articular cartilage
Critical for hip biomechanics
Pipkin II involves this area

Fovea Capitis:

Small depression on femoral head
Attachment of ligamentum teres
Landmark for Pipkin classification
Below fovea = non-weight-bearing

Circumflex femoral arteries anatomy showing medial and lateral circumflex arteries — Circumflex Femoral Arteries. The profunda femoris artery and its branches including the medial femoral circumflex artery (MFCA) - the primary blood supply to the femoral head (80%). The MFCA courses posteriorly and is at risk with posterior hip dislocation, making urgent reduction critical to prevent AVN.Credit: Mikael Häggström, Gray's Anatomy (1918)

Blood Supply (CRITICAL KNOWLEDGE)

Medial Femoral Circumflex Artery (MFCA):

Primary blood supply to femoral head (80%)
Arises from profunda femoris
Courses posterior to femoral neck
Gives off retinacular arteries
AT RISK with posterior dislocation

Lateral Femoral Circumflex Artery:

Minor contribution to head
Supplies greater trochanter primarily

Ligamentum Teres Artery (Foveal Artery):

Branch of obturator artery
Supplies small area around fovea
Contribution variable (significant in 10-20%)
NOT adequate to prevent AVN alone

Why Posterior Dislocation Threatens Blood Supply

MFCA courses posteriorly
Dislocation stretches/kinks artery
Prolonged dislocation = ischemia
Reduction relieves stretch
But damage may be done if delayed

Key Point: Anterior approach for ORIF after posterior dislocation avoids further damage to already compromised posterior blood supply.

Classification Systems

Pipkin Classification (1957)

Pipkin Classification Summary

Type	Fragment Location	Key Feature	Management
Type I	Below fovea	Non-weight-bearing zone	Excise small, ORIF if large
Type II	Above fovea	Weight-bearing zone	ORIF required
Type III	I or II + neck fracture	Very high AVN risk	Arthroplasty (elderly) or fix
Type IV	I or II + acetabular fracture	Complex polytrauma	Combined approaches

Key Landmark

The fovea is the critical landmark. Above fovea = weight-bearing = must fix. Below fovea = non-weight-bearing = may excise if small.

Clinical Presentation

Mechanism

High-Energy Trauma:

Motor vehicle accidents (dashboard injury)
Fall from height
Sporting injuries (rare)
Industrial accidents

Classic Dashboard Mechanism:

Hip flexed and adducted (sitting position)
Knee impacts dashboard
Force transmitted along femur
Posterior dislocation with head fracture

History

Symptoms:

Severe hip/groin pain
Cannot move leg
Leg appears shortened and internally rotated
History of high-energy trauma

Associated Injuries:

Knee injuries (PCL, patella fracture)
Femoral shaft fracture (floating hip)
Other pelvic/acetabular fractures
Sciatic nerve injury (10-20%)

Physical Examination

Classic Posterior Dislocation Position:

Hip flexed, adducted, internally rotated
Shortened leg
Obvious deformity
Unable to move hip

Neurovascular Assessment (MANDATORY):

Structure	Assessment	Injury Rate
Sciatic nerve	Foot dorsiflexion/plantarflexion, sensation	10-20%
Common peroneal	Toe extension, dorsum sensation	Higher risk
Tibial	Toe flexion, plantar sensation	Lower risk
Pulses	Femoral, popliteal, DP, PT	Rare injury

Document Nerve Status BEFORE Reduction:

Crucial for medicolegal purposes
Differentiate injury from iatrogenic damage
Most recover with reduction

Differential Diagnosis

Differential Diagnosis of the Painful, Deformed Hip After Trauma

Diagnosis	Key Distinguishing Features	Discriminating Investigation
Pure posterior hip dislocation (no head fracture)	Flexed, adducted, internally rotated shortened limb; smooth concentric head on post-reduction film	Post-reduction CT shows congruent joint, no intra-articular fragment
Femoral head fracture (Pipkin)	As above plus intra-articular bone fragment relative to fovea	CT defines fragment size and supra- vs infra-foveal location
Femoral neck fracture	Shortened, externally rotated limb; pain on axial loading	AP pelvis/CT shows neck lucency; if combined with head fragment it is Pipkin III
Posterior wall acetabular fracture	May co-exist; joint instability or incongruity after reduction	CT shows posterior wall defect; combined head injury is Pipkin IV
Anterior hip dislocation	Flexed, abducted, externally rotated limb	AP pelvis shows head inferomedial; obturator type lies near foramen
Native hip osteonecrosis / collapse	Atraumatic or low-energy, insidious groin pain, no acute deformity	MRI shows subchondral oedema; not an acute fracture pattern

Investigations

Initial Imaging

AP Pelvis Radiograph:

First-line investigation
Confirm dislocation
Assess for associated fractures
Do NOT delay reduction for imaging

Lateral Hip (if possible):

Assess posterior dislocation
May be difficult to obtain

Post-Reduction Imaging

AP and Lateral Hip:

Confirm concentric reduction
Look for joint space widening (interposed fragment)
Assess for associated fractures

CT Scan (ESSENTIAL After Reduction)

Indications:

All hip dislocations after reduction
Assess femoral head fracture pattern
Identify loose bodies
Plan surgical approach

CT Findings to Document:

Fragment size (% of head)
Fragment location (above/below fovea)
Articular step-off
Loose bodies in joint
Associated acetabular fracture
Femoral neck integrity

3D Reconstruction

Helpful for surgical planning
Visualize fragment orientation
Assess head sphericity
Plan screw trajectory

MRI (Usually Not Acute)

Assess for early AVN (weeks later)
Cartilage damage assessment
Not routine in acute setting

Management Algorithm

Management Principles

Priority Order:

URGENT REDUCTION - Under 6 hours target
Assess fragment size and location (CT)
Remove incarcerated fragments/loose bodies
Fix weight-bearing fragments
Monitor for AVN

Time Critical

Hip dislocation is a TIME EMERGENCY. AVN risk increases dramatically after 6 hours. Reduce in ED if possible. Do NOT delay for elaborate imaging.

Surgical Technique

Smith-Petersen (Anterior) Approach

Preferred for posterior dislocations - protects MFCA

Positioning:

Supine on radiolucent table
Affected hip slightly externally rotated
C-arm available

Approach:

Interval between sartorius and tensor fascia lata
Develop interval to expose hip capsule
Identify ascending branch of lateral femoral circumflex
T-capsulotomy for exposure

Exposure:

Excellent visualization of femoral head
Direct access to anterior/superior head
Can see fragment and reduce anatomically

This approach protects the posterior blood supply.

Complications

Avascular Necrosis (AVN)

Risk Factors:

Dislocation time (most important)
Multiple reduction attempts
Pipkin type (III highest)
Severity of initial injury
Age (higher in older patients)

Incidence by Type:

Pipkin Type	AVN Rate
Type I	10-15%
Type II	15-25%
Type III	40-60%
Type IV	20-30%

Time-Dependent Risk:

Under 6 hours: 10-15%
6-12 hours: 20-40%
Over 12 hours: 50%+

Management of AVN:

Conservative initially if asymptomatic
Core decompression for early stages
Total hip arthroplasty for advanced disease
Young patients: consider joint preservation

Post-Traumatic Arthritis

Incidence: 20-50% at 10 years

Contributing Factors:

Residual articular incongruity
Cartilage damage at injury
AVN progression
Retained loose bodies

Management:

Activity modification
NSAIDs
Intra-articular injections
Total hip arthroplasty for end-stage

Heterotopic Ossification

Risk Factors:

Delayed surgery
Extensive soft tissue trauma
Male gender
Head injury

Prevention:

Indomethacin 75mg daily x 6 weeks
Single-dose radiation (700 cGy)
Low-dose radiation for high risk

Sciatic Nerve Injury

Incidence: 10-20% with posterior dislocation

Prognosis:

Most recover after reduction
Peroneal division worse than tibial
EMG at 3-4 weeks if no recovery

Recurrent Dislocation

Rare
Usually due to malreduced posterior wall
May need revision fixation

Postoperative Care

Immediate Postoperative (0-2 weeks)

Day of Surgery:

Abduction pillow or wedge
DVT prophylaxis (enoxaparin)
Pain management
Hip precautions if needed

First 2 Weeks:

Wound checks
Protected weight-bearing (toe-touch)
Gentle ROM exercises
DVT prophylaxis continued

Early mobilization reduces DVT risk.

Outcomes and Prognosis

Overall Outcomes

Outcomes by Pipkin Type

Pipkin Type	Good/Excellent Result	AVN Rate	Prognosis
Type I	80-90%	10-15%	Best
Type II	70-80%	15-25%	Moderate
Type III	40-50%	40-60%	Poor
Type IV	50-60%	20-30%	Variable

Prognostic Factors

Favorable Factors

Reduction under 6 hours. Pipkin I with small fragment. Anatomic reduction achieved. Young patient. No associated fractures.

Poor Prognostic Factors

Delayed reduction over 12 hours. Pipkin III pattern. Non-anatomic reduction. Multiple reduction attempts. Associated neck fracture.

Long-Term Results

Post-Traumatic Arthritis:

Develops in 20-50% at 10 years
Related to articular incongruity
Cartilage damage at time of injury
May progress despite good initial result

Return to Function:

Most patients return to daily activities
High-impact activities often limited
Athletes may have difficulty returning to sport
Occupational modifications may be needed

Evidence Base

Time to Reduction and Osteonecrosis (Landmark)

III

Hougaard K, Thomsen PB • Arch Orthop Trauma Surg (1986)

Key Findings:

In 100 adult posterior hip dislocations, avascular necrosis occurred in 4.8% of hips reduced within 6 hours versus 52.9% of hips reduced after 6 hours
Higher-grade (Stewart-Milford grade III-IV) dislocations had a significantly higher osteonecrosis rate; skeletal traction and non-weight-bearing showed no protective benefit

Clinical Implication: Emergent reduction within 6 hours is the single most important modifiable factor for reducing osteonecrosis risk

Verify on PubMed (PMID 3566493)

Long-Term Outcome of Posterior Hip Dislocation

Marchetti ME, Steinberg GG, Coumas JM • J Orthop Trauma (1996)

Key Findings:

In 33 patients followed a mean of 49 months, the Pipkin scheme was a useful predictor of outcome: Pipkin 1-2 injuries did significantly better than Pipkin 3-4 (p less than 0.02)
Overall 67% good, 18% fair and 15% poor results, with outcome dependent on anatomic reduction, restoration of stability and removal of all interposed fragments

Clinical Implication: Pipkin type predicts prognosis; anatomic reduction with removal of all loose fragments is the goal of operative care

Verify on PubMed (PMID 8892144)

Surgical Approach and Osteonecrosis Risk

Stannard JP, Harris HW, Volgas DA, Alonso JE • Clin Orthop Relat Res (2000)

Key Findings:

The Kocher-Langenbeck posterior approach was associated with a 3.2-fold higher incidence of avascular necrosis compared with the Smith-Petersen anterior approach
3 mm cannulated screws with threaded washers gave poor functional outcomes and are contraindicated for femoral head fixation

Clinical Implication: The Smith-Petersen anterior approach is recommended for most femoral head fractures after posterior dislocation to protect the medial femoral circumflex supply

Verify on PubMed (PMID 10943184)

Anterior vs Posterior Approach (Meta-Analysis)

III

Wang CG, Li YM, Zhang HF, Li H, Li ZJ • Int J Surg (2016)

Key Findings:

Pooled analysis of five case-control studies of Pipkin I-II fractures found the posterior approach significantly reduced heterotopic ossification compared with the anterior approach
No significant differences were found between approaches for functional outcome, osteonecrosis or post-traumatic arthritis

Clinical Implication: Approach choice should be individualised; heterotopic ossification prophylaxis is particularly relevant when an anterior approach is used

Verify on PubMed (PMID 26854958)

Surgical Hip Dislocation (Ganz) Outcomes

III

Khalifa AA, Haridy MA, Fergany A • World J Orthop (2021)

Key Findings:

Across nine studies (129 fractures), surgical hip dislocation achieved satisfactory clinical outcome in 85% and anatomical reduction in 74% at a mean 38.4 months
Avascular necrosis occurred in 12%, heterotopic ossification in 25% and osteoarthritis in 16%; trochanteric osteotomy nonunion (3.4%) is a unique risk of this approach

Clinical Implication: Surgical hip dislocation offers safe articular access with acceptable osteonecrosis rates but adds the specific risk of trochanteric osteotomy complications

Verify on PubMed (PMID 34485106)

Contemporary Narrative Review

Menger MM, Braun BJ, Herath SC, Küper MA, Rollmann MF, Histing T • EFORT Open Rev (2021)

Key Findings:

Femoral head fractures are rare, typically follow posterior hip dislocation and are classified with the 1957 Pipkin system, which remains the most widely used scheme
Emergency closed reduction followed by approach selection guided by fracture location, displacement, joint congruity and loose fragments is the current standard; osteonecrosis, post-traumatic arthritis and heterotopic ossification drive poorer outcomes

Clinical Implication: Provides an up-to-date synthesis of classification, approach selection and complication profiles for contemporary practice

Verify on PubMed (PMID 34909230)

Viva Scenarios

Clinical Decision Scenarios

Use these scenarios to practise clinical reasoning and management decisions

CLINICAL SCENARIOStandard

Scenario 1: Posterior Hip Dislocation

CLINICAL PROMPT

"A 32-year-old male involved in a high-speed MVA presents with his right leg shortened, flexed, and internally rotated. AP pelvis shows posterior hip dislocation. What is your management?"

PRACTICAL APPROACH

Key Discussion Points:

Time to reduction is critical - target under 6 hours
Document sciatic nerve function BEFORE reduction
Closed reduction technique: Allis or Bigelow maneuver
General anesthesia preferred for muscle relaxation
If closed reduction fails, emergent open reduction
Post-reduction CT is MANDATORY
AVN risk increases dramatically after 6 hours
Assess for associated acetabular and femoral neck fractures
Kocher-Langenbeck approach for irreducible posterior dislocation

KEY CLINICAL POINTS

Reduce within 6 hours to minimize AVN risk

Document sciatic nerve function BEFORE reduction

Post-reduction CT is MANDATORY

Closed reduction: Allis or Bigelow maneuver

COMMON PITFALLS

Delaying reduction for elaborate imaging

Not documenting pre-reduction nerve status

Forgetting post-reduction CT

FURTHER QUESTIONS

"What if closed reduction fails?"

"What is the AVN rate if reduced after 12 hours?"

"How do you perform the Allis maneuver?"

CLINICAL SCENARIOChallenging

Scenario 2: Pipkin Classification

CLINICAL PROMPT

"After reduction of a posterior hip dislocation, CT shows a femoral head fracture with a fragment involving 35% of the head."

PRACTICAL APPROACH

Key Discussion Points:

Type I: Below fovea (inferior) - non-weight-bearing
Type II: Above fovea (superior) - weight-bearing, requires ORIF
Type III: I or II + femoral neck fracture - very high AVN risk
Type IV: I or II + acetabular fracture - complex management
Small Type I: excise fragment and loose bodies
Large Type I (over 20%): consider ORIF
Type II: ORIF with countersunk screws mandatory
Type III elderly: total hip arthroplasty
Type III young: fix neck urgently + address head
Type IV: staged posterior (acetabulum) + anterior (head)

KEY CLINICAL POINTS

Fovea is KEY landmark - above = weight-bearing

Type I small: excise; Type I large: ORIF

Type II always requires ORIF

Type III elderly: consider THA

COMMON PITFALLS

Not knowing Type III has highest AVN risk (40-60%)

Missing the fovea as the critical landmark

Treating all Type I the same regardless of size

FURTHER QUESTIONS

"What size Type I fragment warrants ORIF?"

"What approach for Pipkin II after posterior dislocation?"

"Why is Type III prognosis so poor?"

CLINICAL SCENARIOChallenging

Scenario 3: Pipkin II ORIF

CLINICAL PROMPT

"A CT after reduction of a posterior hip dislocation shows a Pipkin II fracture - the fragment involves 30% of the femoral head above the fovea. No associated neck or acetabular fracture."

PRACTICAL APPROACH

Key Discussion Points:

Anterior approach for posterior dislocation - protects MFCA
Smith-Petersen interval (sartorius/TFL)
T-capsulotomy for exposure
Reduce fragment anatomically
Fixation: countersunk Herbert screws or buried mini-fragment screws
Hardware must NOT protrude above cartilage surface
Remove all loose bodies
Confirm reduction with fluoroscopy
Post-op: protected weight-bearing 6-8 weeks
Monitor for AVN with serial radiographs

KEY CLINICAL POINTS

Use ANTERIOR approach for posterior dislocation (protects MFCA)

Smith-Petersen interval

Countersunk hardware (Herbert screws)

All hardware BELOW cartilage surface

COMMON PITFALLS

Using posterior approach after posterior dislocation (damages MFCA further)

Hardware proud above cartilage

Leaving loose bodies in joint

FURTHER QUESTIONS

"Why anterior approach for posterior dislocation?"

"What is the blood supply to the femoral head?"

"What is the AVN rate for Pipkin II?"

MCQ Practice Points

Classification Question

Q: What is the key anatomical landmark in the Pipkin classification?

A: The fovea capitis. Type I = below fovea (non-weight-bearing), Type II = above fovea (weight-bearing). The fovea determines whether fixation is mandatory.

Time Question

Q: What is the target time for reduction of a traumatic hip dislocation?

A: Under 6 hours. AVN risk is 10-15% if reduced within 6 hours, rising to over 50% if delayed beyond 12 hours.

Approach Question

Q: Which surgical approach is preferred for ORIF of a femoral head fracture after posterior hip dislocation?

A: Anterior (Smith-Petersen) approach. This protects the already-compromised posterior blood supply (MFCA) from further damage.

Blood Supply Question

Q: What is the primary blood supply to the femoral head?

A: Medial femoral circumflex artery (MFCA) provides 80% of blood supply via retinacular vessels. It courses posteriorly and is at risk with posterior dislocation.

Management Question

Q: How should a Pipkin III fracture be managed in an elderly patient?

A: Total hip arthroplasty. The combination of femoral head and neck fracture has very high AVN rates (40-60%). In elderly patients, arthroplasty provides better functional outcomes.

Guidelines, Registries & Global Practice

Global Epidemiology

Femoral head fractures are rare injuries that occur almost exclusively after high-energy posterior hip dislocation, most often from motor vehicle dashboard injuries or falls from height. According to PubMed, the contemporary EFORT narrative review (Menger et al., 2021) confirms they remain uncommon and are still classified worldwide using the 1957 Pipkin system, with osteonecrosis, post-traumatic arthritis and heterotopic ossification as the principal drivers of poorer long-term outcome.

Side-by-Side Guidance and Evidence

Body / Guideline Position on Femoral Head Fractures

Body	Core Position	Evidence Basis
AAOS / OTA (North America)	Emergent closed reduction of the dislocation, then CT, then ORIF of weight-bearing fragments; anterior approach favoured after posterior dislocation	Expert consensus on level III-IV cohorts
BOAST / BOA (UK)	Reduce dislocation as an emergency, document neurovascular status, post-reduction CT mandatory, definitive fixation in a unit with pelvic-acetabular expertise	Standards for trauma (consensus)
AO Foundation	Classification-led: excise small non-weight-bearing fragments, fix supra-foveal fragments with countersunk headless screws	Technique consensus
EFORT (Europe)	Approach individualised to fragment location, displacement and loose bodies; no single approach proven superior for osteonecrosis	Narrative review (Menger 2021)

Registry and Pooled Evidence

Because femoral head fractures are rare, no national joint registry isolates them as a discrete cohort; registry data (AOANJRR in Australia, NJR in England and Wales, AJRR in the United States) inform only the salvage arthroplasty pathway for Pipkin III injuries and post-traumatic arthritis. The highest-level synthesis comes from pooled studies: a meta-analysis of Pipkin I-II fractures found the posterior approach reduced heterotopic ossification without affecting osteonecrosis (Wang et al., 2016), while a systematic review of surgical hip dislocation reported osteonecrosis in 12%, heterotopic ossification in 25% and osteoarthritis in 16% (Khalifa et al., 2021).

Practice Variation

Approach: North American and many European units favour the anterior (Smith-Petersen) approach after posterior dislocation to protect the medial femoral circumflex artery; others prefer the Ganz surgical hip dislocation for full articular visualisation, accepting trochanteric osteotomy-related risk.
Heterotopic ossification prophylaxis: more routinely used after anterior and extensile approaches; indometacin or single-dose radiotherapy regimens vary by region.
Salvage in the elderly: primary total hip arthroplasty for Pipkin III in older patients is widely accepted internationally, reflecting the very high osteonecrosis risk of combined head-and-neck injuries.
Australian context: in major trauma centres, femoral head fractures are managed with emergent reduction within 6 hours under general anaesthesia, universal post-reduction CT, and rehabilitation through the public system with private cover available for elective salvage procedures.

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