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Femoral Neck Fractures Steven A. Olson, MD Original Author: Brian Boyer, MD; March 2004; New Author: Steven A. Olson, MD; Revised March 2006. Anatomy. Physeal closure age 16 Neck-shaft angle 130° ± 7° Anteversion 10° ± 7° Calcar Femorale Posteromedial
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Femoral Neck FracturesSteven A. Olson, MDOriginal Author: Brian Boyer, MD; March 2004; New Author: Steven A. Olson, MD; Revised March 2006
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 • Greater fracture displacement = greater risk of vascular disruption to femoral head • 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 I II 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
TreatmentDecision 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
TreatmentYoung 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
TreatmentElderly 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]
TreatmentPre-operative Considerations • Skin Tractionnot 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
TreatmentPre-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
TreatmentPre-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
Open Reduction or Closed Reduction? Open reduction can be considered for any displaced femoral neck fractures that are treated with reduction and internal fixation Open reduction is indicated after an attempt at gentle closed reduction results in a non-anatomic reduction Primary open reduction is preferred in young patients with a displaced femoral neck fracture
Approach For Open Reduction Smith-Peterson • Anterior approach • Best for transcervical and subcapitol fractures • Fixation is performed through a second approach
Approach For Open Reduction Watson-Jones • Anteriolateral exposure • Best for basalar neck and IT patterns • Allows placement of sliding hip screw through same incision
What Reduction Is Acceptable? • Ideal reduction is Anatomic • Acceptable: < 15º valgus < 10º AP angulation • Any varus is unacceptable • 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
Screw Fixation • Screw location • Avoid posterior/ superior quadrant • Blood supply • Cut-out • Biomechanical advantage to inferior/ calcar screw [Booth 1998]
Sliding Compression Screw Fixation • 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
Intracapsular Hematoma • incidence- 75% have some intracapsular pressure • no difference displaced/nondisplaced • sensitive to leg position • extension + internal rotation= bad • animal models: intracapsular pressure = perfusion • Theoretical benefit with NO clinical proof • but it doesn’t hurt
Open reduction via Smith-Pete approach, screw fixation placed through separate incision
Displaced FracturesHemiarthroplasty 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 FracturesHemiarthroplasty 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]
HemiarthroplastyUnipolar vs. Bipolar • Bipolar theoretical advantages • Lower dislocation rate • Less acetabular wear/ protrusio • Less Pain • More motion
HemiarthroplastyUnipolar vs. Bipolar • Bipolar • Disadvantages • Cost • Dislocation often requires open reduction • Loss of motion interface (effectively unipolar) • Polyethylene wear/ osteolysis not yet studied for Bipolars
HemiarthroplastyUnipolar 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
HemiarthroplastyCemented 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)
HemiarthroplastyCemented 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
TreatmentPre-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 FracturesTreatment • 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 FracturesComplications • 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 NeckNonunion • 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 NeckNonunion • Treatment • Elderly patients • Arthroplasty • Results typically not as good as primary elective arthroplasty • Girdlestone Resection Arthroplasty • Limited indications • deep infection?
Femoral NeckNonunion • 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