Summary Intertrochanteric Fractures are common extracapsular fractures of the proximal femur at the level of the greater and lesser trochanter that are most commonly seen following ground-level falls in the elderly population. Diagnosis is made with orthogonal radiographs of the hip. MRI is most helpful to evaluate occult hip fractures. Treatment is generally operative with sliding hip screw versus cephalomedullary nail depending on fracture stability. Epidemiology Incidence account for ~50% of hip fractures 150,000 intertrochanteric fractures per year in US 500 per 100,000 population per year for elderly female 200 per 100,000 population per year for elderly male Demographics age average ~80 years old typically older age than femoral neck fractures female: male ratio between 2:1 and 8:1 Risk factors proximal humerus fractures increase risk of hip fracture for 1 year osteoporosis advancing age increased number of comorbidities increased dependency with ADLs Etiology Pathophysiology mechanism elderly low energy falls in osteoporotic patients young high energy trauma Associated conditions osteoporosis recurrent falls dementia parkinsons unsteady gait visual impairment medications Anatomy Osteology neck shaft angle 130 +/- 7 degrees anteversion 10 +/- 7 degrees intertrochanteric area exists between greater and lesser trochanters calcar femorale vertical wall of dense bone that extends from posteromedial aspect of femoral shaft to posterior portion of femoral neck level of involvement helps determine stable versus unstable fracture patterns radius of curvature of femur average 114-120 cm factors that decrease radius of curvature (increased bowing) elderly asian short stature Muscles deforming forces on proximal segment flexion iliopsoas sartorius rectus femoris pectineus external rotation piriformis superior gemellus obturator internus inferior gemellus quadratus femoris abduction gluteus maximus gluteus medius gluteus minimus tensor fascia lata deforming forces on distal segment adduction and shortening adductor longus adductor brevis adductor magnus gracilis overall varus alignment Blood supply rich collateral circulation reduces risk of nonunion trochanteric anastomosis ascending branch of medial circumflex femoral artery (MFCA) ascending branch of lateral circumflex femoral artery (LFCA) deep branch of superior gluteal artery inferior gluteal artery transverse branch of LFCA and MFCA periosteum and surrounding muscles Biomechanics Ward's triangle area of lowest BMD in femoral neck bordered by 3 main compressive/tensile trabeculae primary compressive trabeculae extends from medial femoral head along calcar and excellent support to proximal femur vertically oriented with a triangular configuration principal tensile trabeculae forms an arc through the superior cortex of the femoral head and neck extends from greater trochanter to inferior aspect of femoral head below fovea secondary compressive trabeculae fan-like configuration crossing from greater trochanter to lesser and also comprises calcar Classification Stability most commonly used and reliable classification two types stable definition intact posteromedial cortex clinical significance will resist medial compressive loads once reduced unstable definition fracture will collapse into varus or shaft will displace medially examples large or comminuted posteromedial cortex i.e. lesser trochanteric fragment reverse obliquity or transtrochanteric fracture line extending from medial cortex out through lateral cortex subtrochanteric extension other considerations lateral wall thickness measured from 3 cm distal from innominate tubercle at 135 degrees to the fracture site <20.5 mm suggest risk of postoperative lateral wall fracture should be treated with cephalomedullary nail (CMN) rather than sliding hip screw (SHS) key role in stabilizing proximal femur by providing lateral buttress AO/OTA Classification 31A -A1 peritrochanteric simple two part intact lateral cortex 31A-A2 pertrochanteric with separate posteromedial fragment intact lateral cortex 31A-A3 fracture extends through lateral and medial cortex Evans classification (based on post-reduction stability) Stable fracture posteromedial cortex intact or minimal comminution able to resist compressive loads Unstable fracture greater comminution of posteromedial cortex can be converted to a stable pattern if medial cortical opposition obtained Reverse obliquity unstable due to medial displacement of femoral shaft due to adductors Presentation History mechanism of injury low-energy most common in elderly higher-energy may be associated with other injuries pre-injury functional status predictor of postoperative functional status antecedent hip pain presence of OA or pathological fracture history of anticoagulation factors into surgical timing list of comorbidites (ASA classification) Symptoms acute onset of hip pain inability to ambulate Physical Exam inspection shortened, externally rotated lower extremity palpation tenderness over greater trochanter motion pain with log roll and axial load unable to perform active straight leg raise assess thigh compartments neurovascular assessment Imaging Radiographs recommended views AP pelvis AP hip cross table lateral full length femur optional traction internal-rotation view improve accuracy of fracture classification with direct impact on surgical planning findings AP pelvis compare to contralateral hip and assess neck shaft angle AP hip defines fracture pattern cross-table lateral helps assess for posterior cortex comminution full length femur assess subtrochanteric extension possibility of pathological fracture estimate length of intramedullary nail assess femoral bowing assess canal diameter CT indication second line imaging to evaluate for occult fracture no access or contraindication to MRI views thin, 1-2 mm slice cuts diagnostic accuracy sensitivity 86% specificity 98% MRI indication occult hip fracture AAOS recommendation: moderate strength isolated greater trochanteric fracture to evaluate for intertrochanteric extension findings bone marrow edema STIR or fat-suppressed T2 line of decreased intensity on T1 coronal view corresponding with signal on T2 and STIR diagnostic accuracy sensitivity T1-weighted 100% (most sensitive) T2-weighted 84% Bone scan indication contraindication to MRI rarely used improved access to MRI and CT delay in care false negative up to 72 hours from injury diagnosis accuracy variable with sensitivity up to 98% Treatment Nonoperative indications nonambulatory patients high risk for perioperative mortality skin breakdown at surgical site incomplete fractures modalities non-weight bearing with early mobilization from bed to chair outcomes high mortality rate 84.4% at 1-year higher rates of pneumonia, UTI, decubitus ulcers, and DVT low risk of displacement with occult fracture Operative intramedullary hip screw (cephalomedullary nail) indications stable fracture patterns AAOS recommendation: strong for use of either SHS or CMN unstable fracture patterns AAOS recommendation: strong for use of CMN reverse obliquity fractures AAOS recommendation: strong for use of CMN 56% failure rate when treated with SHS subtrochanteric extension AAOS recommendation: strong for use of CMN lack of integrity of femoral wall associated with increased displacement and collapse when treated with SHS increased risk of lateral wall fracture with decreasing lateral wall thickness technique short CMN long CMN outcomes stable fracture pattern similar clinical and radiographic outcomes for SHS vs CMN unstable fracture pattern lower reoperation rate with CMN CMN use has significant increased over last decade open reduction and internal fixation (ORIF) indications stable fracture pattern AAOS recommendation: strong for use of either SHS or CMN techniques sliding hip compression (SHS) screw (most common) proximal femur locking plate 95 degree blade plate (rarely used) outcomes similar outcomes for stable fracture patterns when compared to CMN arthroplasty indications (rare) salvage for failed internal fixation severely comminuted fractures preexisting severe degenerative hip arthritis severely osteoporotic bone that is unlikely to hold internal fixation Techniques Intramedullary hip screw (cephalomedullary nail) pros biologically friendly with potentially closed technique less estimated blood loss (EBL) can be used in unstable fracture patterns decreased bending strain on implant load sharing device with shorter lever arm on implant intramedullary buttress limits shaft medialization cons periprosthetic fracture higher implant cost than sliding hip screw violation of hip abductors for insertion approach supine on fracture table lateral decubitus on radiolucent table technique short vs long CMN controversial AAOS recommendation: limited short CMN advantage ease of use decreased OR time decreased EBL lower implant cost long CMN advantage theoretical benefit of protecting entire femur disadvantage increased OR time increased EBL increased radiation exposure possible mismatch of implant bow and femur outcomes similar functional outcomes, peri-implant fracture, and cutout rate short nail can tolerate up to 3-4 cm of subtrochanteric extension lag screw versus helical blade controversial lag screw proven track record femoral head rotation during insertion helical blade theoretical benefit of compacting cancellous bone around blade during insertion avoids removal of bone with reamer biomechanical studies showing higher cutout resistance complication lag screw or helical blade cutout anterior perforation of femur perimplant fracture Open reduction and internal fixation Sliding hip compression screw technique must obtain correct neck-shaft relationship lag screw with tip-apex distance <25 mm is associated with reduced failure rates 4 hole plates show no benefit clinically or biomechanically over 2 hole plates pros allows dynamic interfragmentary compression lower implant cost no violation of hip abductors cons open technique increased blood loss not advisable in unstable fracture patterns excessive fracture collapse limb shortening medialization of shaft anterior spike malreduction in left-sided, unstable fractures due to screw torque place derotational wire or screw prior to lag screw insertion proximal femoral locking plate indication infrequently used consider in young patient with unstable fracture pros allow for intraoperative fracture compression avoid excessive postoperative fracture compression maintain limb length avoid shaft medicalization cons limited evidence highly dependent on surgeon experience must obtain anatomic reduction Arthroplasty technique long stem with calcar-replacing prosthesis often needed must attempt fixation of greater trochanter to shaft pros possible early return to unrestricted weight bearing not reliant on internal fixation in osteoporotic bone cons increased blood loss and OR time increased cost may require prosthesis that some surgeons are less familiar with Complications Implant failure and cutout incidence occurs in 4-20% usually occurs within first 4 months risk factors older age osteoporosis fracture type quality of reduction tip-apex distance (TAD) sum of distances from tip of lag screw to apex of femoral head on AP and lateral after adjusting for magnification goal TAD <25mm TAD >45 mm associated with 60% failure rate treatment young corrective osteotomy and/or revision open reduction and internal fixation elderly or articular injury from screw cutout total hip arthroplasty Nonunion and malunion incidence <2% uncommon due to good blood supply varus malreduction can occur with excessively lateral starting point (>3mm) leads to varus collapse and screw cutout diagnosis hip pain with persistent radiolucent defect at fracture site 4-7 months after surgery CT scan may help confirm diagnosis rule out infection treatment valgus intertrochanteric osteotomy + bone grafting arthroplasty screw cutout has damaged hip joint Peri-implant fracture incidence 1-3% at 1 year no significant difference between short and long CMN short CMN typically fracture just distal to tip of nail long CMN typically fracture more around the rod (as opposed to the tip) risk factors distal interlocking screw protective against fracture treatment short CMN distally inserted lateral femoral plate with cables revise to long CMN long CMN closed reduction and insertion of distal locking screw distal femoral plating (fracture distal to tip) Anterior perforation of the distal femur incidence mostly seen with insertion of long CMN decreased with improvements in nail radius of curvature to better match patient anatomy risk factors mismatch of the radius of curvature of the femur (shorter) and implant (longer) posterior starting point on the greater trochanter Postoperative anemia and transfusions blood transfusion >30% postoperative transfusion rate AAOS moderate recommendation transfusion threshold no higher than 8g/dL in asymptomatic postop hip fracture transexamic acid (TXA) AAOS strong recommendation for use decrease EBL decrease postoperative blood transfusion Prognosis Mortality 15-30% mortality risk in the first year following fracture 84.4% at one year with nonoperative treatment Factors that increase mortality male gender (25-30% mortality) vs female (20% mortality) higher in intertrochanteric fracture (vs femoral neck fracture) operative delay of >2 days age >85 years 2 or more pre-existing medical conditions ASA classification (ASA III and IV increases mortality) Factors that decrease mortality Surgery within 48 hours decreases 1 year mortality AAOS moderate recommendation for hip fracture surgery within 24-48 hours of admission early medical optimization and co-management with medical hospitalists or geriatricians AAOS strong recommendation for use of interdisciplinary care teams In the absence of clear risk factors for valvular disease, arrhythmias, worsening heart failure, or coronary artery stenosis, an echocardiogram is unlikely to change peri-operative complications and has been shown to delay time to surgical fixation Loss of independence community-dwelling ambulators at 1-year 41% maintain pre-injury ambulatory status 40% more dependent on assistive devices 12% became household ambulators 8% became nonfunctional ambulators One-third general rule 1/3 regain function 1/3 lose one level of independence 1/3 mortality rate