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 traction-internal rotation AP hip is best for defining fracture type 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 may be considered in some patients who are non-ambulators, have minimal pain, and who are at high risk for surgical intervention Operative closed reduction with cannulated screw fixation indications nondisplaced transcervical fx Garden I or II in the physiologically elderly displaced transcervical fx in young patient achieve reduction to limit vascular insult reduction must be anatomic, so open if necessary open reduction internal fixation (ORIF) indications displaced fractures in young or physiologically young patients ORIF indicated for most pts <50 years of age female sex associated with increased reoperation rate techniques sliding hip screw indications basicervical fracture vertical fracture pattern in a young patient sliding hip screw biomechanically superior to cannulated screws (may not be clinically superior) consider placement of additional cannulated screw above sliding hip screw to prevent rotation hemiarthroplasty indications controversial debilitated elderly patients metabolic bone disease techniques cemented hemiarthroplasty decreased intraoperative and postoperative fracture rates in elderly insufficiency fractures improved short and medium term mobility total hip arthoplasty indications controversial older active patients patients with preexisting hip osteoarthritis more predictable pain relief and better functional outcome than hemiarthroplasty Garden III or IV in patient < 85 years Techniques General Technical Principles time to surgery controversial reduction method and quality has more pronounced effect on healing than surgical timing elderly patients with hip fractures should be brought to surgery as soon as medically optimal (preferably <24-48 hours) the benefits of early mobilization cannot be overemphasized improved outcomes in medically fit patients if surgically treated less than 4 days from injury preoperative echocardiograms have been shown to delay the time to surgery without any effect on treatment decisions anesthesia type spinal versus general no difference in postoperative delirium, mortality or ambulatory function at 60 days 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) 1-inferior screw along calcar 2-posterior/superior screw 3-anterior/superior screw 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 clear advantage of additional screws not proven in literature 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 10cm skin incision made beginning just distal to ASIS incise deep fascia develop interval between sartorious and TFL external rotation of thigh accentuates dissection plane LFCN is identified and retracted medially with sartorius identify tendinous portion of rectus femoris, elevate off hip capsule open capsule to identify femoral neck Watson-Jones used to gain improved exposure of lower femoral neck fractures skin incision approx 2cm posterior and distal to ASIS, down toward tip of greater trochanter incision curved distally and extended 10cm along anterior portion of femur incise deep fascia develop interval between TFL and gluteus medius anterior aspect of gluteus medius and minimus is retracted posteriorly to visualize anterior hip capsule capsule sharply incised with Z-shape incision capsulotomy must remain anterior to lesser trochanter at all times to avoid injury to medial femoral circumflex artery reduction open versus closed reduction worse outcomes with displacement > 5 mm (higher rate of osteonecrosis and nonunions) no consensus on which reduction approach is superior multiple closed reduction attempts are associated with higher risk of osteonecrosis of the femoral head technique evacuate hematoma place A to P k-wires into femoral neck/head proximal to fracture to use as joysticks for reduction insert starting k-wire (for either cannulated screw or sliding hip screw) into appropriate position laterally, up to but not across the fracture once reduction obtained, drive starting k-wire across fracture insert second threaded tipped k-wire if adding additional fixation fixation fixation with implants that allow sliding permit dynamic compression at fx site during axial loading can cause shortening of femoral neck prominent implants affects biomechanics of hip joint lower physical function on SF-36 decreased quality of life anatomic reduction with intraop compression and placement of length stable devices decrease shortening 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) cemented also associated with lower rates of postoperative periprosthetic femur fractures 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%) about five times higher than hemiarthroplasty 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 AVN can still develop in nondisplaced injuries nonanatomical reduction sliding hip screw reported by the FAITH study treatment major symptoms not always present when AVN develops young patient > 50% involvement then treat with FVFG vs THA older patient prosthetic replacement (hemiarthroplasty vs THA) 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 indicated in patients after femoral neck nonunion can be done even in presence of AVN, as long as not severely collapsed turns vertical fx line into horizontal fx line and decreases shear forces across fx line free vascularized fibula graft (FVFG) indicated in young patients with a viable femoral head arthroplasty indicated in older patients or when the femoral head is not viable also an option in younger patient with a nonviable femoral head as opposed to FVFG 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 46% failure with fixation techniques 8% failure with arthroplasty techniques 2-to-10 year follow-up failure rate approx. 2-4%, respectively 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 Normal TUG is <12 seconds in all age groups Persistent use of ambulatory aids is predicted if TUG > 26 seconds 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