This document summarizes information on femoral neck fractures including: 1) The anatomy, blood supply, epidemiology, classification systems, and treatment options for femoral neck fractures. 2) ORIF is the standard treatment for non-displaced fractures while hemiarthroplasty is preferred over ORIF for displaced fractures in elderly patients. 3) Stress fractures of the femoral neck present differently than traumatic fractures and often require urgent ORIF if the fracture line extends over 50% across the neck.

1. Femoral Neck Fractures
Brian Boyer, MD

2. Anatomy
• Physeal closure age 16
• Neck-shaft angle
130° ± 7°
• Anteversion
10° ± 7°
• Calcar Femorale
Posteromedial
dense plate of bone

3. 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

4. Blood Supply
 fracture displacement=vascular disruption
• revascularization of the head
– intact vessels
– vascular ingrowth across fracture site
• importance of quality of reduction
– metaphyseal vessels

5. 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

6. Classification
• Pauwels [1935]
– Angle describes vertical shear vector

7. 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
I II
III IV

8. Classification
• Functional Classification
– Stable
• Impacted (Garden I)
• Non-displaced (Garden II)
– Unstable
• Displaced (Garden III and IV)

9. Treatment
• Goals
– Improve outcome over natural history
– Minimize risks and avoid complications
– Return to pre-injury level of function
– Provide cost-effective treatment

10. Treatment
• Options
– Non-operative
• very limited role
• Activity modification
• Skeletal traction
– Operative
• ORIF
• Hemiarthroplasty
• Total Hip Replacement

11. 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

12. Treatment
Young Patients
(Arbitrary physiologic age < 65)
– Non-displaced fractures
• At risk for secondary displacement
• Urgent ORIF recommended
– Displaced fractures
• Patients native femoral head best
• AVN related to duration and degree of displacement
• Irreversible cell death after 6-12 hours
• Emergent ORIF recommended

13. 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]

14. Treatment
Pre-operative Considerations
• Skin Traction not beneficial
– 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

15. 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

16. 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

17. ORIF
Hemi
THR

18. 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

19. 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

20. ORIF
• Screw location
– Avoid posterior/ superior quadrant
» Blood supply
» Cut-out
– Biomechanical advantage to inferior/ calcar screw
[Booth 1998]

21. 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

22. 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

23. 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%

24. Displaced Fractures
Hemiarthroplasty vs. ORIF
• Hemi associated with
• 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]

25. Hemiarthroplasty
Unipolar vs. Bipolar
• Bipolar theoretical advantages
• Lower dislocation rate
• Less acetabular wear/ protrusio
• Less Pain
• More motion

26. 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

27. 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

28. 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)

29. Hemiarthroplasty
Cemented vs. Non-cemented
• Conclusion:
– Cement gives better results
• Function
• Mobility
• Implant Stability
• Pain
• Cost-effective
– Low risk of sudden cardiac
death
• Use cement with caution

30. 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]

31. 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]

32. 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
Keating et al OTA 2002

33. 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

34. Stress Fractures
• Clinical Presentation
– Activity / weight bearing related
– Anterior groin pain
– Limited ROM at extremes
– ± Antalgic gait
– Must evaluate back, knee, contralateral hip

35. 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

36. Stress Fractures
• Classification
– Compression sided
• Callus / fracture at inferior aspect femoral neck
– Tension sided
• Callus / fracture at superior aspect femoral neck
– Displaced

37. 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

38. 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%

39. Femoral Neck
Nonunion
• Definition: not healed by one year
• 0-5% in Non-displaced fractures
• 9-35% in Displaced fractures
• Increased incidence with
– Posterior comminution
– Initial displacement
– Inadequate reduction
– Non-compressive fixation

40. Femoral Neck
Nonunion
• Clinical presentation
– Groin or buttock pain
– Activity / weight bearing related
– Symptoms
• more severe / occur earlier than
AVN
• Imaging
– Radiographs: lucent zones
– CT: lack of healing
– Bone Scan: high uptake
– MRI: assess femoral head
viability

41. Femoral Neck
Nonunion
• Treatment
– Elderly patients
• Arthroplasty
– Results typically not as good as primary elective
arthroplasty
• Girdlestone Resection Arthroplasty
– Limited indications
– deep infection?

42. 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

43. Osteonecrosis (AVN)
Femoral Neck Fractures
• 5-8% Non-displaced fractures
• 20-45% Displaced fractures
• Increased incidence with
– INADEQUATE REDUCTION
– Delayed reduction
– Initial displacement
– associated hip dislocation
– ?Sliding hip screw / plate devices

44. 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

45. 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

46. 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 **

47. 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

48. 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

49. Femoral Neck Fractures
Complications
• One-year mortality 14-50%
• Increased risk:
– Medical comorbidities
– Surgical delay > 3 days
– Institutionalized / demented patient
– Arthroplasty (short term / 3 months)
– Posterior approach to hip
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Lower Extremity
Index