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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 I II III IV Classification • Functional Classification – Stable • Impacted • Non-displaced (Garden I) (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 Return to Lower Extremity Index