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Femoral Neck Fractures

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Femoral Neck Fractures Powered By Docstoc
					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                    I      II
    Non-displaced
III Complete
    Partial displacement
IV Complete
    Full displacement
** Portends risk of AVN
    and Nonunion               III    IV
               Classification
• Functional Classification
  – Stable
     • Impacted        (Garden I)
     • Non-displaced   (Garden II)
  – Unstable
     • Displaced       (Garden III and IV)
                  Treatment
• Goals
  –   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
   •   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
  –   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
      •   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
     •   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
  –   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
•   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
                      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
                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
  –   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:
  –   Medical comorbidities
  –   Surgical delay > 3 days
  –   Institutionalized / demented patient
  –   Arthroplasty (short term / 3 months)
  –   Posterior approach to hip

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