Hip And Femur Flashcards
Radiographic evaluation of femoral head fxs: 2 views
AP and Judet-45 degree oblique
Classification name and system for femoral head fxs
Pipkin
Type 1: hip dislocation with fracture of the fem head INFERIOR to the fovea capitis femoris
Type 2: “….” SUPERIOR to the fovea capitis femoris
Type 3: type 1 or 2 injury with fx of femoral neck
Type 4: type 1 or 2 injury with fx of acetabular rim
Tx for Pipkin type 3 fx
Young pt: emergent ORIF for fem neck followed by internal fixation for fem head. Anterolateral approach (Watson-Jones)
Old pt with displaced femoral neck: prosthesis
- Poor prognosis, 50% AVN
Tx for Pipkin type 4
Acetabular fx dictates approach. Femoral head should be internally fixed for early motion of hip
3 ligaments of the hip capsule:
1: Ileofemoral (Y ligament of Bigelow) - anterior
2: Pubofemoral - anterior
3: Ischiofemoral - posterior
2 classification systems used for femoral neck fxs
1: Pauwel
2: Garden
Radiographic views for femoral neck fx (3)
AP pelvis, AP hip and cross table lateral
Garden classification system for femoral neck fxs:
Based on the degree of valgus displacement
Type 1: incomplete/valgus impaction
Type 2: complete and nondisplaced on AP and lateral views
Type 3: complete with partial displacement; trabecular pattern of the femoral head does not line up with that of the acetabulum
Type 4: completely displaced
Tx of fatigue/stress femoral neck fractures: tension sided vs compression sided
Tension: superior-lateral portion of neck - at significant risk for displacement. In situ screw fixation recommended
Compression: inferior neck (haze of callus at inferior neck) - protective crutch ambulation 2/2 minimal risk for displacement
Tx of impacted/nondisplaced femoral neck fractures
In situ fixation with 3 cancellous screws to prevent displacement (up to 40% will displace w/o internal stabilization); exception = pathologic fxs, severe OA/RA, Paget may require prosthesis
Tx of displaced femoral neck fractures in elderly and young pts
Elderly: high functioning - THA; low demand/poor bone quality - hemi with unipolar prosthesis
Young: ORIF with multiple screw fixation (3 in inverting triangle; avoid being distal to lesser) or sliding screw sideplate device with second pin/screw to control rotation (consider DHHS if basicervical)
Unlike femoral neck fxs, intertroch fxs do not have as many problems with nonunion and osteonecrosis. Why?
Extracapsular - occur in cancellous bone and good blood supply
What are the 3 deforming muscular forces with intertroch fxs - produce shortening, ER, and varus position
Abductors: displace greater troch laterally and proximally
Iliopsoas: lesser troch medially and prox
Hip flexors, extensors, adductors: distal frag prox
Surgical tx options for intertroch fxs?
1: sling hip screw
2: IM hip screw nail (cephalomedullary)
Mechanism and Tx of isolated greater troch fxs
Mechanism: eccentric muscle contraction or direct blow; Nonop in elderly. Young active pt: ORIF with tension band wiring or plate and screw fixation with a hookplate
Why are basicervical fxs treated like intertroch fxs?
Extracapsular, lack of cancellous interdigitation seen in intertroch region makes them more susceptible to rotation
Classification system used for intertrochanteric fractures
Evans - based on prereduction and postreduction stability –> convertibility of an unstable fx config to a stable reduction
Unstable intertrochanteric fx pattern
Greater comminution of Posteromedial cortex; subtroch extension or reverse obliquity pattern
Most important technical aspects of screw insertion with intertroch fxs
1: placement within 1 cm of subchondral bone for secure fixation.
2: central position in the femoral head
Russel-Taylor subtroch fx classification: (may be obsolete now)
Importance: guide to implant choice between first and second generation cephalomedullary nails
Type 1: fractures with an intact piriformis fossa:
Type 1A: lesser troch attached to prox frag
Type 1B: lesser is DETACHED from prox frag
Type 2: fractures that extend into the piriformis fossa
Type 2A: stable medial construct (Posteromedial cortex)
Type 2B: comminution of the piriformis fossa and lesser troch
Tx of subtroch fx:
IM nail or 95 degree fixed angle plate; proximal femur precontoured locking plates are a new alternative to traditional fixed angle plates and screws
Tx of isolated greater troch fxs:
Nonop in elderly. Young active pt: ORIF with tension band wiring or plate and screw fixation with a hookplate
Standard of care surgically for femoral shaft fxs: Should take place within 24 hours!
IM nail - should be statically locked to maintain femoral length and control rotation
Indications for use of external fixation for femoral shaft fxs: 3
1: temporary bridge to IM nailing (up to 2 weeks)
2: ipsilateral artery damage that requires repair
3: severe soft tissue contamination in whom a second debridement would be limited by other devices
Average angulation and direction of anatomic axis (shaft of femur and knee joint)
Valgus angulation of 9 degrees (7-11 degrees)
Stable fx pattern for intertrochanteric
Posteromedial cortex remains intact and has little comminution
Tx of stable, nondisplaced fxs of the distal femur:
Nonop tx of displaced fxs:
Mobilization of the extremity in a hinged knee brace, with partial weight bearing.
Non op: 6-12 week period of casting with acceptance of resultant deformity followed by bracing. Objective is restoration of knee joint axis to a normal relationship with the hip and ankle
3 classification systems for subtroch fxs
1: Fielding
2: Seinsheimer
3: Russell-Taylor
Two types of injury that are present in roughly 50% of femoral shaft fractures:
Ligamentous and meniscal injuries
Blood supply to the cortex of the femur:
Outer 1/3 supplied by periosteal vessels. Inner 2/3 supplied by endosteal
Following most femoral shaft fxs, _____ vessels are disrupted and _____ vessels proliferate to act as the primary source of healing
Endosteal vessels are disrupted, periosteal vessels proliferate
Classification system for femoral shaft fxs based on fx comminution
Winquist and Hansen
Winquist and Hansen classification system for femoral shaft fxs:
Type 1: minimal or no displacement
Type 2: cortices of both fragments at least 50% intact
Type 3: 50-100% cortical comminution
Type 4: circumferential comminution with no cortical contact
General rule of thumb for skeletal traction of femoral shaft fxs
1/9 or 15% body weight of traction (usually 20-40 pounds)
Potentially negative effects of reaming before IM nail placement in femoral fxs: (4)
1: elevated IM pressures
2: elevated pulmonary artery pressures
3: increased fat emboli
4: increased pulmonary dysfxn
Potential advantages of reaming before IM nail placement in femur fxs (3)
1: ability to place larger nail
2: increased Union
3: decreased hardware failure
Site and mechanism of vascular injury in femoral shaft fxs
Tethering of the femoral artery at the adductor hiatus
Radiographic eval for distal femur fxs:
AP, lateral, two 45 degree oblique. Should include the entire femur. Consider traction views to view alignment
Classification system used for distal femur fractures
Neer - based on direction of displacement of distal fragments
Operative treatment option for distal femur fractures (5):
1: young adults with good bone stock in unicondylar fxs = INTERFRAG SCREWS
2: to control alignment one of these 3 methods = 95 degree condylar blade plate, dynamic condylar screw (DCS), locking plates with fixed angled screws
3: IM nails: anterograde for supracondylar, retrograde for distal fixation
Classic appearance of patient with posterior hip dislocation vs anterior dislocation:
Post: flexion, internal rotation, adduction
Ant: marked external rotation, mild flexion, abduction
Radiographic images ordered with hip dislocation
AP pelvis and cross table lateral
What should you look for on the AP view of the pelvis when evaluating hip dislocations (5)
1: Femoral heads should appear similar in size
2: Joint spaces should be symmetric throughout
3: Shenton’s line should be smooth and continuous
4: Appearance of greater and lesser trochs for pathologic rotation; adduction vs abduction
5: femoral neck to rule out fracture
AP radiograph findings in posterior hip dislocation:
AP radiograph findings in anterior hip dislocation:
1: Affected femoral head appears smaller
2: Affected femoral head appears slightly larger