Emergent closed reduction as soon as feasible, preferably within 6 hours. ⢠If irreducible, or with femoral neck fracture, then ORIF .... More vertically oriented fractures may also require plate fixation ... Percutaneous Cancellous (PC) Screw.
Proximal Femur Fractures “What the orthopedic surgeon really wants to know”
Jeffrey Y. Shyu1, Scott Sheehan1, Michael Weaver2, Jeffrey F.B. Chick1, Aaron D. Sodickson1, Bharti Khurana1
1. Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School 2. Department of Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School
Disclosures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
DePuy Synthes – Educational Grant (M Weaver)
Learning Objectives Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Provide an intuitive understanding of the morphologic types, injury mechanisms, and classification systems of adult proximal femur fractures, using multimodality imaging examples, 3-D models, and animations.
Review the potential management.
complications
and
Proximal Femur Fractures: Organization Tree Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Proximal femur fractures may be divided into femoral head, intracapsular femoral neck, and extracapsular fractures. Accurately categorizing the anatomic location and subtype of the fracture has significant implications for surgical management.
Proximal Femur Fractures
Femoral Head
Intracapsular
Extracapsular
Intertrochanteric Subcapital Osteochondral
Greater Trochanter Transcervical Lesser Trochanter
Subchondral Basicervical*
Subtrochanteric
* Basicervical fractures, although intracapsular, are managed like intertrochanteric fractures.
Proximal Femur Fractures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
subtrochanteric greater lesser trochanter fracture fracture osteochondral subcapital intertrochanteric fracture subchondral basicervical transcervical
Anatomy Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
MOVIE: Computer generated tour of the relevant muscular, ligamentous, labral, and bony anatomy of the hip.
Anatomy Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References The hip is a synovial joint with wide range of rotational motion and stability. Stability is conferred by its ball and deep socket configuration, acetabular labrum, a strong joint capsule, articular cartilage, and surrounding muscle. One of the few inherently stable joints because of its bony anatomy. Iliofemoral and pubofemoral ligaments cover hip joint anteriorly. Ischiofemoral ligament covers hip joint posteriorly.
Byrne DP et al. The Open Sports Medicine Journal 2010
Anatomy: Arterial Supply Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Medial femoral circumflex artery • Largest, most important contributor • Posterior portion of vascular ring • Supplies superolateral femoral head
Obdurator art.
Lateral femoral circumflex artery • Anterior portion of vascular ring • Supplies inferoanterior femoral head
Med. fem circumflex Lat. fem circumflex Deep femoral art.
A major concern of femoral head and neck fractures is disruption of the arterial supply, which results in avascular necrosis. In fractures, the intraosseous cervical vessels are disrupted.
Trueta J et al. J Bone Joint Surg BR 1953; Ly TV et al. J Boint Joint Surg Am 2008.
Ascending cervical arteries • • • •
Feeder vessels arising from extracapsular ring Penetrate capsule Run parallel to femoral neck towards the head Lateral vessels provide greatest supply
Obdurator artery • Via ligamentum teres • Little supply to femoral head, inadequate in setting of displaced head/heck fractures
Anatomy: Stress Lines Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Hip experiences combined mechanical loads • Axial load along shaft, compressive stress • Bending load along neck, tensile stress applied at upper neck and compressive stress at lower neck
Cancellous bone arranged along principal lines of stress Ward’s Triangle
• Primary medial trabeculae resist compression • Primary lateral trabeculae resist tension
Stress lines explain patterns of injury Tensile group Compressive
Byrne DP et al. The Open Sports Medicine Journal 2010; Bowman KF Arthroscopy 2010.
Ward’s Triangle: Weakest point of femoral neck
Imaging Modalities Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Plain Film Radiography • First line study • 90% sensitive, however 2-11% of ED patients have radiologically occult fractures • AP and lateral radiographs of the hip • AP radiograph of the pelvis, to assess for pelvic injury and compare with contralateral hip
CT • More readily accessible than MRI in acute ED settings • Useful in trauma for detecting intra-articular extension, acetabular fracture, pelvic ring, and sacral fractures • However, second-line compared to MRI because of concerns for missing fracture lines • May be useful for preoperative evaluation
Coronal CT demonstrates a femoral neck fracture with valgus impaction (arrow)
Dominguez S et al. Acad Emerg Med 2005; Frihagen F et al. Acta Orthop 2005; Kirby MW et al. AJR Am J Roentgenol 2010; Khurana B et al. AJR 2012
Imaging Modalities Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
MRI • Obtain if radiographs are negative/equivocal and clinical suspicion is high • More sensitive than CT for evaluating occult fractures • Best for evaluating bone marrow, joint space, osteochondral injuries, early diagnosis and staging of AVN • May be limited in access in an acute ED setting • Technique: Useful MR sequences include the following: coronal STIR, coronal T1, axial dual-echo, axial T2 fat-saturated FSE, axial fat-saturated FSE proton density, sagittal T1, axial T1. • Most useful sequences are coronal STIR (for edema) and coronal T1 (for fracture line)
Bone Scan • Indicated for suspected fracture or AVN not demonstrated on plain film, and where MRI unavailable • High sensitivity, but poor specificity • Minimum of 4 hours to perform, and may take up to 24-48 hours • Relatively less useful in osteoporotic patients • Poor spatial localization of fracture lines
Dominguez S et al. Acad Emerg Med 2005; Frihagen F et al. Acta Orthop 2005; Kirby MW et al. AJR Am J Roentgenol 2010 Khurana B et al. AJR 2012
Occult Femoral Neck Fracture Seen Only on MRI Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
AP radiograph of the hip demonstrates no evidence of fracture.
On coronal T1 MRI, a hypointense fracture line is present.
Up to 11% of ED patients have radiologically occult hip fractures
Dominguez S et al. Acad Emerg Med 2005
Traumatic Femoral Head (Osteochondral) Fractures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Traumatic femoral head fractures typically result from high energy impact, and are often associated with hip dislocations Posterior dislocations 9x more common than anterior Partial flexion, internal rotation typically leads to a posterior fracture-dislocation pattern
Ross JR et al. Curr Rev Musculosk Med. 2012
Femoral Head Fractures: Pipkin Classification Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Most commonly used classification for femoral head fractures, and used to guide operative versus nonoperative management
Posterior dislocation Fracture below fovea, non-weight-bearing
Posterior dislocation Fracture above fovea, weight-bearing
Associated femoral neck fracture
Type I, II, or III, associated acetabular fracture
Rockwood and Green’s Fractures in Adults 2010; Ross JR et al. Curr Rev Musculosk Med 2012
Traumatic Femoral Head Fractures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Femoral head fracture with subfoveal involvement (Pipkin I)
Femoral head fracture with posterior dislocation
Traumatic Femoral Head Fractures: Surgical Considerations Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Intra-capsular fracture, concern for avascular necrosis • •
Emergent closed reduction as soon as feasible, preferably within 6 hours If irreducible, or with femoral neck fracture, then ORIF
Above or below fovea? • •
Above fovea, weight bearing Below fovea, non-weight bearing, could potentially be treated conservatively
Is traction indicated? • If fracture flipped, then traction indicated
Congruent? • If incongruent, then operative management
Management Strategies • Conservative management: Pipkin I • ORIF: Pipkin II, Pipkin III, IV, irreducible fracture-dislocation • Core decompression for osteonecrosis is controversial
Rockwood and Green’s Fractures in Adults 2010; Ross JR et al. Curr Rev Musculosk Med. 2012
Subchondral Insufficiency Versus Osteonecrosis Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Subchondral insufficiency fractures are a recently recognized entity that may mimic osteonecrosis of the femoral head. However, certain clinical and imaging features will favor one diagnosis over the other.
A
B
Subchondral Insufficiency: coronal STIR (A) demonstrates irregular band parallel to the femoral head. Post-contrast T1 image (B) in a different patient demonstrates femoral head enhancement
Osteonecrosis: coronal T1: bilateral decreased T1 signal in the femoral heads, and serpiginous bands concave to articular surface
Subchondral Insufficiency
Osteonecrosis
• •
• • •
Biphasic pattern: elderly females and young active individuals Typically unilateral
Typically 30s-40s in age Associated with steroid/alcohol use 50-70 percent bilateral
MRI • Irregular, hypointense disconnected band that runs almost parallel to femoral head • High signal proximal segment on C+ images
MRI • T1: Smooth band that is concave to the articular surface, and circumscribes necrotic segments
Treatment
Treatment
•
• •
No femoral head collapse • Young: Trochanteric rotational osteotomy • Elderly: THA or hemiarthroplasty
Yamamoto T Clin Orthop Surg 2012; Ikemura S et al. AJR 2010
No femoral head collapse: conservative treatment Femoral head collapse: THA or hemiarthroplasty
Femoral Neck Fracture: Mechanism Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Caused by fall with applied force to the greater trochanter High energy impact in younger patients, and low energy impact in elderly patients Weakest site just below articular surface
Subcapital, Transcervical, Basicervical Fractures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Subcapital Treated as intracapsular fx
Transcervical
Basicervical
Treated as intracapsular fx
Treated as extracapsular fx e.g. like intertrochanteric fx
Garden Classification Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
I
II
Commonly used classification for surgical management of femoral neck fractures Incomplete Valgus impaction + retroversion
III
Complete, non-displaced
IV
Valgus impacted fractures are often missed Good interobserver agreement between I-II and III-IV, but poor between all groups Better to distinguish I-II and III-IV, as types III and IV typically treated with arthroplasty
Marked angulation Minimal/no proximal translation
Complete displacement Proximal translation
Frandsen PA et al. Acta Orthop Scand 1984; Kreder HJ J Bone Joint Surg AM 2002
Pauwel Classification Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Type I
Type II
More stable
Type III
Most common
More unstable, higher energy injury
Determined by angle of fracture from horizontal plane Increased shear forces with increased angles worsens prognosis Better categorizes stability than the Garden Classification Better predicts difficulty of obtaining stable fixation More vertically oriented fractures may also require plate fixation Type III fractures complicated by nonunion may require intertrochanteric osteotomy to reorient the fracture line to a more Type 1 (stable) angle
Ly TV et al. J Bone Joint Surg Am 2008
Types of Stress Fractures Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Femoral neck stress fractures are often related to increased activity. The pattern of the stress fracture relates to the lines of stress within the proximal femur and has significant management implications
Tensile
Compressive
Unstable, fracture can propagate
More stable
Displaced Unstable Worse prognosis and risk for avascular necrosis Emergent operation and reduction
Femoral Neck: Tensile Stress Fracture Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Tensile Stress Fracture Superior, lateral aspect of the femoral neck Bimodal distribution: Elderly individuals and young runners Potentially unstable, obtain MRI to assess fracture extent Warrants internal fixation (nail fixation in young athletes)
Femoral Neck: Tensile Stress Fracture Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Tensile stress fracture in the superolateral femoral neck in an elderly patient. Note osteoarthritis of the hip.
Tensile stress fracture (Garden III) in the superolateral femoral neck in a young, active, patient. Note the normal bone mineral density.
Bimodal distribution: elderly individuals and young runners
Femoral Neck: Fatigue Compression Fracture Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References Coronal STIR image demonstrates edema at the inferomedial femoral neck.
Coronal T1 image demonstrates a hypointense region and a subtle fracture line.
Fatigue Compression Fracture Inferior aspect of femoral neck Active individuals May potentially be treated non-operatively
Femoral Neck Fractures: Surgical Considerations Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
AVN, nonunion may result from delayed diagnosis • Risk for AVN is greater for femoral neck fractures than for pertrochanteric fractures
Young ( < 65) and/or active • Goal: preserve femoral head, avoid osteonecrosis, achieve union
Old ( > 75) and/or immobile • Goal: restore mobility and minimize complications
Fracture pattern determines treatment • Basicervical fracture treated like intertrochanteric fracture • Nonoperative management associated with higher complication and increased risk of displacement • If nondisplaced, internal fixation preferred • If displaced fracture, elderly, arthroplasty preferred • Most studies find improved function with THA compared to hemiarthroplasty
Miler BJ et al. J Bone Joint Surg Am 2013; Goh SK et al. J Arthroplasty 2009; Cserhati P et al. Injury 1996
Femoral Neck Fracture: Treatment Algorithm Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Young
Old
Nondisplaced
Percutaneous Cancellous (PC) Screw
PC Screw or Arthroplasty
Displaced
Open Reduction Internal Fixation
Miler BJ et al. J Bone Joint Surg Am 2013
Total Hip Arthroplasty Hemiarthroplasty
Intertrochanteric Fracture Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Anatomy • Intertrochanteric line: anterior ridge between greater and lesser trochanters • Extracapsular, transition between femoral neck and shaft • Iliofemoral ligament attaches above, vastus medialis attaches below
Mechanism • Resulting from fall
Unstable features • Loss of medial buttress • 4-part fractures, and 3-part fractures with lesser trochanter involvement • Reverse obliquity • Comminution
Stable features • • • • Nondisplaced Intertrochanteric fracture (Evans I)
Koval KJ et al. J Am Acad Orthop Surg 1994
Near anatomic reduction achievable Lesser trochanter nondisplaced Medial cortices in alignment No comminution
Evans Classification Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Useful for deciding stability and treatment of intertrochanteric fractures. Also, reverse obliquity fractures are unstable and treated like subtrochanteric fractures
I
III
II
Two part, undisplaced Stable
Two part, displaced Stable
IV Three part, posteromedial comminution Unstable
Trafton PG. Orthop Clin North Am 1987; Koval KJ et al. J Am Acad Orthop Surg 1994
Three part, posterolateral comminution Unstable
V Four Part Unstable
Intertrochanteric Fracture: Management Disclosures Learning Objectives Organization Anatomy Imaging Osteochondral Subchondral Femoral Neck Intertrochanteric Greater Troch. Lesser Troch. Subtrochanteric Conclusion References
Management depends on completeness and stability Risk of AVN and nonunion less than in femoral neck fractures Again, basicervical fractures treated like intertrochanteric fractures
Complete
Incomplete
• •
• •
Stable: Dynamic plate and screw Unstable or reverse obliquity: Intramedullary device
Su BW, Orthopedics 2006; Forte ML et al. J Bone Jint Surg Am 2008
•
Obtain MRI to ensure fracture not complete If incomplete and
