Summary Femoral neck fractures are common injuries to the proximal femur associated with increased risk of avascular necrosis, and high levels of patient morbidity and mortality. Diagnosis is generally made radiographically with orthogonal radiographs of the hip. Treatment is generally operative with open reduction and internal fixation versus arthroplasty depending on the age of the patient, activity demands and pre-injury mobility. Epidemiology Incidence common increasingly common due to aging population Demographics women > men Caucasians > African Americans United states has highest incidence of hip fx rates worldwide Etiology Pathophysiology healing potential femoral neck is intracapsular, bathed in synovial fluid lacks periosteal layer callus formation limited, which affects healing Mechanism high energy in young patients low energy falls in older patients Associated injuries femoral shaft fractures 6-9% associated with femoral neck fractures treat femoral neck first followed by shaft Anatomy Osteology normal neck shaft-angle 130 +/- 7 degrees normal anteversion 10 +/- 7 degrees Blood supply to femoral head major contributor is medial femoral circumflex (lateral epiphyseal artery) some contribution to anterior and inferior head from lateral femoral circumflex some contribution from inferior gluteal artery small and insignificant supply from artery of ligamentum teres displacement of femoral neck fracture will disrupt the blood supply and cause an intracapsular hematoma (effect is controversial) Classification Garden Classification (based on AP radiographs and does not consider lateral or sagittal plane alignment) Type I Incomplete fx (valgus impacted) Type II Complete fx, nondisplaced Type III Complete fx, partially displaced Type IV Complete fx, fully displaced Simplified Garden Classification Nondisplaced Includes Garden I and II Displaced Includes Garden IIII and IV Pauwels Classification (based on vertical orientation of fracture line) Type I < 30 deg from horizontal Type II 30 to 50 deg from horizontal Type III > 50 deg from horizontal (most unstable with highest risk of nonunion/AVN) Presentation Symptoms impacted and stress fractures slight pain in the groin or pain referred along the medial side of the thigh and knee displaced fractures pain in the entire hip region Physical exam impacted and stress fractures no obvious clinical deformity minor discomfort with active or passive hip range of motion, muscle spasms at extremes of motion pain with percussion over greater trochanter displaced fractures leg in external rotation and abduction, with shortening Imaging Radiographs recommended views AP login to view 1 more bullet cross-table lateral full-length femur optional views consider obtaining dedicated imaging of uninjured hip to use as template intraop CT indications helpful in determining displacement and degree of comminution in some patients MRI indications helpful to rule out occult fracture not helpful in reliably assessing viability of femoral head after fracture Bone scan indications helpful to rule out occult fracture not helpful in reliably assessing viability of femoral head after fracture Duplex Scanning indications rule out DVT if delayed presentation to hospital after hip fracture Treatment Nonoperative observation alone indications login to view 1 more bullet Operative closed reduction with cannulated screw fixation indications login to view 5 more bullets open reduction internal fixation (ORIF) indications login to view 3 more bullets techniques login to view 6 more bullets hemiarthroplasty indications login to view 3 more bullets techniques login to view 3 more bullets total hip arthoplasty indications login to view 5 more bullets Techniques General Technical Principles time to surgery controversial login to view 1 more bullet elderly patients with hip fractures should be brought to surgery as soon as medically optimal (preferably <24-48 hours) login to view 3 more bullets anesthesia type spinal versus general login to view 1 more bullet treatment approach based on degree of displacement physiologic age of the patient (young is < than 50 years old) ipsilateral femoral neck and shaft fractures Closed reduction with cannulated screw fixation technique three screws if noncomminuted (3 screw inverted triangle shown to be superior to two screws) order of screw placement (this varies) login to view 3 more bullets obtain as much screw spread as possible in femoral neck inverted triangle along the calcar (not central in the neck) has stronger fixation and higher load to failure four screws considered for posterior comminution login to view 1 more bullet starting point at or above level of lesser trochanter to avoid fracture avoid multiple cortical perforations during guide pin or screw placement to avoid development of lateral stress riser Open reduction internal fixation (ORIF) approach limited anterior Smith-Peterson login to view 7 more bullets Watson-Jones login to view 8 more bullets reduction open versus closed reduction login to view 3 more bullets technique login to view 5 more bullets fixation fixation with implants that allow sliding login to view 7 more bullets Hemiarthroplasty approach posterior approach has increased risk of dislocations anterolateral approach has increased abductor weakness technique cemented superior to uncemented in elderly population (decreased revision rates) login to view 1 more bullet unipolar vs. bipolar Total Hip Replacement technique should consider using the anterolateral approach and selective use of larger heads in the setting of a femoral neck fracture advantages improved functional hip scores and lower re-operation rates compared to hemiarthroplasty and internal fixation complications higher rate of dislocation with THA (~ 10%) login to view 1 more bullet Complications Osteonecrosis incidence of 10-45% recent studies fail to demonstrate an association between time to fracture reduction and subsequent AVN increased risk with increase initial displacement login to view 1 more bullet nonanatomical reduction sliding hip screw login to view 1 more bullet treatment major symptoms not always present when AVN develops young patient login to view 1 more bullet older patient login to view 1 more bullet Nonunion incidence of 5 to 30% increased incidence in displaced fractures no correlation between age, gender, and rate of nonunion varus malreduction most closely correlates with failure of fixation after reduction and cannulated screw fixation. treatment valgus intertrochanteric osteotomy login to view 3 more bullets free vascularized fibula graft (FVFG) login to view 1 more bullet arthroplasty login to view 2 more bullets revision ORIF Dislocation higher rate of dislocation with THA (~ 10%) about seven times higher than hemiarthroplasty risks of dislocation after a hemiarthroplasty posterior approach with poor capsular repair intraoperative labral injury or posterior wall fracture oversizing the femoral head Failure rates high early failure rates in fixation group, which stabilizes after 2 years 2-year follow-up (elderly population >70 years) with displaced femoral neck fractures login to view 2 more bullets 2-to-10 year follow-up login to view 1 more bullet overall failure rates still higher in fixation vs. arthoplasty at 10-year follow-up sliding hip screw with lower reoperation rates compared to cannulated screws displaced femoral neck fractures basicervical femoral neck fractures current smokers Reducing complications with co-management service orthopaedic geriatric co-management of trauma patients has been demonstrated to yield decreased mortality, post-operative complications, time to surgery, length of stay (though conflicting results on length of stay) improved post-operative mobility at 4 months important to mitigate risks of hospital delirium which may lead to increased length of stay Loss of independence requiring walking aids and assisted living following fracture surgery the timed up and go (TUG) test has been identified as a reliable predictor of a patient's need for post-operative assistive devices login to view 2 more bullets associated factors age >80 years ASA class >1 prior walking aid use current tobacco use implant placement quality nondisplaced fracture not requiring revision surgery Prognosis Most expensive fracture to treat on per-person basis Mortality ~25-30% at one year (higher than vertebral compression fractures) Predictors of mortality pre-injury mobility is the most significant determinant for post-operative survival in patients with chronic renal failure, rates of mortality at 2 years postoperatively, are close to 45% mortality risk is decreased at 30 days and at 1 year post-op when surgical intervention is performed within 24 hours of admission