Transcript Femoral Neck Fractures

Femoral Neck Fractures
Brian Boyer, MD
Anatomy
• Physeal closure age 16
• Neck-shaft angle
130° ± 7°
• Anteversion
10° ± 7°
• Calcar Femorale
Posteromedial
dense plate of bone
Blood Supply
• Lateral epiphysel artery
– terminal branch MFC artery
– predominant blood supply to
weight bearing dome of head
• Artery of ligamentum teres
– from obturator artery
– supplies anteroinferior head
• Lateral femoral circumflex a.
– less contribution than MFC
Blood Supply
• fracture displacement=vascular
disruption
• revascularization of the head
– intact vessels
– vascular ingrowth across fracture site
• importance of quality of reduction
– metaphyseal vessels
Epidemiology
• 250,000 Hip fractures annually
– Expected to double by 2050
• At risk populations
– Elderly: poor balance&vision, osteoporosis, inactivity,
medications, malnutrition
• incidence doubles with each decade beyond age 50
– higher in white population
– Other factors: smokers, small body size, excessive
caffeine & ETOH
– Young: high energy trauma
Classification
• Pauwels [1935]
– Angle describes vertical shear vector
Classification
• Garden [1961]
I
Valgus impacted or
incomplete
II Complete
Non-displaced
III Complete
Partial displacement
IV Complete
Full displacement
** Portends risk of AVN and
Nonunion
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II
III
IV
Classification
• Functional Classification
– Stable
• Impacted
• Non-displaced
(Garden I)
(Garden II)
– Unstable
• Displaced
(Garden III and IV)
Treatment
• Goals
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Improve outcome over natural history
Minimize risks and avoid complications
Return to pre-injury level of function
Provide cost-effective treatment
Treatment
• Options
– Non-operative
• very limited role
• Activity modification
• Skeletal traction
– Operative
• ORIF
• Hemiarthroplasty
• Total Hip Replacement
Treatment
Decision Making Variables
• Patient Characteristics
– Young (arbitrary physiologic age < 65)
• High energy injuries
– Often multi-trauma
• High Pauwels Angle (vertical shear pattern)
– Elderly
• Lower energy injury
• Comorbidities
• Pre-existing hip disease
• Fracture Characteristics
– Stable
– Unstable
Treatment
Young Patients
(Arbitrary physiologic age < 65)
– Non-displaced fractures
• At risk for secondary displacement
• Urgent ORIF recommended
– Displaced fractures
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Patients native femoral head best
AVN related to duration and degree of displacement
Irreversible cell death after 6-12 hours
Emergent ORIF recommended
Treatment
Elderly Patients
• Operative vs. Non-operative
– Displaced fractures
• Unacceptable rates of mortality, morbidity, and poor outcome
with non-operative treatment [Koval 1994]
– Non-displaced fractures
• Unpredictable risk of secondary displacement
– AVN rate 2X
– Standard of care is operative for all femoral neck
fractures
• Non-operative tx may have developing role in select patients
with impacted/ non-displaced fractures [Raaymakers 2001]
Treatment
Pre-operative Considerations
• Skin Traction not beneficial
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No effect on fracture reduction
No difference in analgesic use
Pressure sore/ skin problems
Increased cost
Traction position decreases capsular volume
• Potential detrimental effect on blood flow
Treatment
Pre-operative Considerations
• Regional vs. General Anesthesia
– Mortality / long term outcome
• No Difference
– Regional
• Lower DVT, PE, pneumonia, resp depression, and
transfusion rates
– Further investigation required for definitive
answer
Treatment
Pre-operative Considerations
• Surgical Timing
– Surgical delay for medical clearance in
relatively healthy patients probably not
warranted
• Increased mortality, complications, length of stay
– Surgical delay up to 72 hours for medical
stabilization warranted in unhealthy patients
Hemi
ORIF
THR
Non-displaced Fractures
• ORIF standard of care
• Predictable healing
– Nonunion < 5%
• Minimal complications
– AVN < 8%
– Infection < 5%
• Relatively quick procedure
– Minimal blood loss
• Early mobilization
– Unrestricted weight bearing with assistive device PRN
ORIF
• Ideal reduction is Anatomic
– Acceptable: < 15º valgus < 10º AP angulation
* may need to open in order achieve reduction
• Fixation: Multiple screws in parallel
– No advantage to > 3 screws
– Uniform compression across fracture
– In-situ pin impacted fractures
* ↑ AVN with disimpaction [Crawford 1960]
– Fixation most dependent on bone density
ORIF
• Screw location
– Avoid posterior/ superior quadrant
» Blood supply
» Cut-out
– Biomechanical advantage to inferior/ calcar screw
[Booth 1998]
ORIF
• Compression Hip Screws
– Sacrifices large amount of bone
– May injure blood supply
– Biomechanically superior in
cadavers
– Anti-rotation screw often needed
– Increased cost and operative time
• No clinical advantage over
parallel screws
* May have role in high energy/ vertical shear
fractures
ORIF
Intracapsular Hematoma
• incidence- 75% have some 
– no difference displaced/nondisplaced
• ? Amount of  > 100 mm in 25%
• sensitive to leg position
– extension + internal rotation= bad
• animal models: pressure= perfusion
• Theoretical benefit with NO clinical proof
– but it doesn’t hurt
Displaced Fractures
Hemiarthroplasty vs. ORIF
• ORIF is an option in elderly
** Surgical emergency in young patients **
• Complications
• Nonunion 10 -33%
• AVN 15 – 33%
• AVN related to displacement
• Early ORIF no benefit
• Loss of reduction / fixation failure 16%
Displaced Fractures
Hemiarthroplasty vs. ORIF
• Hemi associated with
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Lower reoperation rate (6-18% vs. 20-36%)
Improved functional scores
Less pain
More cost-effective
Slightly increased short term mortality
• Literature supports hemiarthroplasty for displaced
fractures
[Lu-yao JBJS 1994]
[Iorio CORR 2001]
Hemiarthroplasty
Unipolar vs. Bipolar
• Bipolar theoretical advantages
• Lower dislocation rate
• Less acetabular wear/ protrusio
• Less Pain
• More motion
Hemiarthroplasty
Unipolar vs. Bipolar
• Bipolar
– Disadvantages
• Cost
• Dislocation often requires open
reduction
• Loss of motion interface
(effectively unipolar)
• Polyethylene wear/ osteolysis
not yet studied for Bipolars
Hemiarthroplasty
Unipolar vs. Bipolar
– Complications / Mortality / Length of stay
• No Difference
– Hip Scores / Functional Outcomes
• No significant difference
• Bipolar slightly better walking speeds, motion, pain
– Revision rates
• Unipolar 20% vs. Bipolar 10% (7 years)
– Unipolar more cost-effective
• Literature supports use of either implant
Hemiarthroplasty
Cemented vs. Non-cemented
• Cement (PMMA)
– Improved mobility, function, walking aids
– Most studies show no difference in morbidity /
mortality
• Sudden Intra-op cardiac death risk slightly increased:
– 1% cemented hemi for fx vs. 0.015% for elective arthroplasty
• Non-cemented (Press-fit)
– Pain / Loosening higher
– Intra-op fracture (theoretical)
Hemiarthroplasty
Cemented vs. Non-cemented
• Conclusion:
– Cement gives better results
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Function
Mobility
Implant Stability
Pain
Cost-effective
– Low risk of sudden cardiac
death
• Use cement with caution
Treatment
Pre-operative Considerations
• Surgical Approach
– Posterior approach to hip
• 60% higher short-term mortality vs. anterior
– Dislocation rate
• No significant difference
[Lu-Yao JBJS 1994]
Total Hip Replacement
• Dislocation rates:
– Hemi 2-3% vs. THR 11% (short term)
• 2.5% THR recurrent dislocation
[Cabanela Orthop 1999]
• Reoperation:
– THR 4% vs. Hemi 6-18%
• DVT / PE / Mortality
• no difference
• Pain / Function / Survivorship / Cost-effectiveness
• THR better than Hemi
[Lu –Yao JBJS 1994]
[Iorio CORR 2001]
Keating et al OTA 2002
ORIF or Replacement?
• Prospective, randomized study ORIF vs.
cemented bipolar hemi vs. THA
• ambulatory patients > 60 years of age
– 37% fixation failure (AVN/nonunion)
– similar dislocation rate hemi vs. THA (3%)
– ORIF 8X more likely to require revision
surgery than hemi and 5X more likely than
THA
– THA group best functional outcome
Stress Fractures
• Patient population:
– Females 4–10 times more common
• Amenorrhea / eating disorders common
• Femoral BMD average 10% less than control
subjects
– Hormone deficiency
– Recent increase in athletic activity
• Frequency, intensity, or duration
• Distance runners most common
Stress Fractures
• Clinical Presentation
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Activity / weight bearing related
Anterior groin pain
Limited ROM at extremes
± Antalgic gait
Must evaluate back, knee, contralateral hip
Stress Fractures
• Imaging
– Plain Radiographs
• Negative in up to 66%
– Bone Scan
• Sensitivity 93-100%
• Specificity 76-95%
– MRI
• 100% sensitivity / specificity
• Also Differentiates: synovitis, tendon/
muscle injuries, neoplasm, AVN,
transient osteoporosis of hip
Stress Fractures
• Classification
– Compression sided
• Callus / fracture at inferior aspect femoral neck
– Tension sided
• Callus / fracture at superior aspect femoral neck
– Displaced
Stress Fractures
Treatment
• Compression sided
• Fracture line extends < 50% across neck
– “stable”
– Tx: Activity / weight bearing modification
• Fracture line extends >50% across neck
– Potentially unstable with risk for displacement
– Tx: Emergent ORIF
• Tension sided
• Unstable
– Tx: Emergent ORIF
• Displaced
– Tx: Emergent ORIF
Stress Fractures
Complications
• Tension sided and Compression sided fx’s
(>50%) treated non-operatively
• Varus malunion
• Displacement
– 30-60% complication rate
• AVN 42%
• Delayed union 9%
• Nonunion 9%
Femoral Neck
Nonunion
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Definition: not healed by one year
0-5% in Non-displaced fractures
9-35% in Displaced fractures
Increased incidence with
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Posterior comminution
Initial displacement
Inadequate reduction
Non-compressive fixation
Femoral Neck
Nonunion
• Clinical presentation
– Groin or buttock pain
– Activity / weight bearing related
– Symptoms
• more severe / occur earlier than
AVN
• Imaging
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Radiographs: lucent zones
CT: lack of healing
Bone Scan: high uptake
MRI: assess femoral head
viability
Femoral Neck
Nonunion
• Treatment
– Elderly patients
• Arthroplasty
– Results typically not as good as primary elective
arthroplasty
• Girdlestone Resection Arthroplasty
– Limited indications
– deep infection?
Femoral Neck
Nonunion
• Young patients
(must have viable femoral head)
– Varus alignment or limb
shortened
• Valgus-producing osteotomy
– Normal alignment
• Bone graft / muscle-pedicle
graft
• Repeat ORIF
Osteonecrosis (AVN)
Femoral Neck Fractures
• 5-8% Non-displaced fractures
• 20-45% Displaced fractures
• Increased incidence with
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INADEQUATE REDUCTION
Delayed reduction
Initial displacement
associated hip dislocation
?Sliding hip screw / plate devices
Osteonecrosis (AVN)
Femoral Neck Fractures
• Clinical presentation
– Groin / buttock / proximal thigh pain
– May not limit function
– Onset usually later than nonunion
• Imaging
– Plain radiographs: segmental collapse / arthritis
– Bone Scan: “cold” spots
– MRI: diagnostic
Osteonecrosis (AVN)
Femoral Neck Fractures
• Treatment
– Elderly patients
» Only 30-37% patients require reoperation
• Arthroplasty
– Results not as good as primary elective
arthroplasty
• Girdlestone Resection Arthroplasty
– Limited indications
Osteonecrosis (AVN)
Femoral Neck Fractures
• Treatment
– Young Patients
» NO good option exists
• Proximal Osteotomy
– Less than 50% head collapse
• Arthroplasty
– Significant early failure
• Arthrodesis
– Sugnificant functional limitations
** Prevention is the Key **
Femoral Neck Fractures
Complications
• Failure of Fixation
– Inadequate / unstable reduction
– Poor bone quality
– Poor choice of implant
• Treatment
– Elderly: Arthroplasty
– Young: Repeat ORIF
Valgus-producing osteotmy
Arthroplasty
Femoral Neck Fractures
Complications
• Post-traumatic arthrosis
• Joint penetration with hardware
• AVN related
• Blood Transfusions
– THR > Hemi > ORIF
– Increased rate of post-op infection
• DVT / PE
– Multiple prophylactic regimens exist
– Low dose subcutaneous heparin not effective
Femoral Neck Fractures
Complications
• One-year mortality 14-50%
• Increased risk:
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Medical comorbidities
Surgical delay > 3 days
Institutionalized / demented patient
Arthroplasty (short term / 3 months)
Posterior approach to hip
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Lower Extremity
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