Trauma - Femur/Tibia (Complete) Flashcards
Per the Lower Extremity Assessment Project (LEAP) study, what were theoutcomes of amputation vs limb salvage?
[JAAOS 2011;19(suppl 1):S20-S22]
No difference in outcomes with amputation versus limb salvage at 2- and 7-year followup
Per the LEAP study, what factors influenced outcomes of amputation/limb salvage?
[JAAOS 2011; 19(suppl 1): S20-S22]
Outcomes were influenced more by patient economic, social, and personal resources than by the initial treatment
- Patient characteristics and the patient’s environment are the factors that most affect outcomes
- Regardless of initial surgical treatment (eg, amputation, limb salvage), medical complications, or the extent of residual physical limitations
Per the LEAP study, what is the difference in cost for amputation vs limb salvage?
[JBJS 2010;92:2852-68]
The lifetime cost for the amputation group was estimated to be about three times higher secondary to prosthesis-related expenses
Per the LEAP study, what role should an insensate foot play in deciding between amputation vs limb salvage?
[JBJS 2010;92:2852-68]
An insensate foot on presentation should not be a critical indication for amputation, as there was a return of plantar sensation by two years in the majority of cases
What are the indications for lower extremity amputation following lower extremity trauma?
[JBJS 2010;92:2852-68]
Absolute
- Blunt or contaminated traumatic amputation
- Mangled extremity in critically injured patient in shock
- Crushed extremity with arterial injury and a warm ischemia time greater than 6 hours
Relative indications
- Severe bone or soft tissue loss
- Anatomic transection of the tibial nerve
- Open tibial fracture with serious associated polytrauma or a severe ipsilateral foot injury
- Prolonged predicted course to obtain soft tissue coverage and tibial reconstruction
What is the blood supply to the femoral head?
[JAAOS 2016;24:515-526]
Primary = medial femoral circumflex artery
- Femoral artery → profunda femoris artery → medial femoral circumflex artery → ascending branch → deep branch
What is the Garden Classification of femoral neck fractures based on AP?
Type I – incomplete, valgus impacted
Type II – complete, nondisplaced
Type III – complete, partial displacement
Type IV – complete, full displacement
What is the Simplified Garden Classification for femoral neck fractures?
- Nondisplaced = Garden I and II
- Displaced = Garden III and IV
What is Pauwel’s classification of femoral neck fractures?
Based on the obliquity of the fracture line with respect to the horizontal
- Type I - 0-30 degrees
- Type II - 30-50 degrees
- Type III - >50 degrees
- Most unstable
- Highest risk of nonunion and AVN
What are signs of adequate femoral neck reduction?
- Restoration of Shenton’s line
- Garden alignment index
- Angle of compression trabeculae to femoral shaft on AP should be 160 degrees
- Angle of compression trabeculae to femoral shaft on lateral should be 180 degrees
- Lowell’s alignment theory
* Head neck junction should make a smooth ‘S’/reverse ‘S’ on all views - Restoration of the neck shaft angle
What are the techniques for closed reduction of a femoral neck fracture to obtain anatomical alignment?
- Leadbetter [World J Orthop 2014 July 18; 5(3): 204-217]
- Hip flexion to 45
- Slight abduction
- Longitudinal traction
- Internal rotation
- Extension
- Flynn [Injury; 5: 309-217]
- Flexion of the hip with slight abduction
- Traction in line with the long axis of the femoral neck
- Extend and internally rotate the hip while traction is maintained
What residual deformity following femoral neck reduction is not acceptable?
[JOT 2015;29:121–129]
- Varus angulation
- Inferior offset
- Retroversion
***These 3 factors increase the risk of nonunion, loss of reduction and osteonecrosis
In the young patient, what means of anatomical reduction is preferred – open vs. closed?
[JOT 2015;29:121–129]
- Both are acceptable as long as anatomical reduction achieved
- If closed unsuccessful proceed to open reduction
What approaches are used for open reduction of a femoral neck fracture in the young adult and what are the advantages and disadvantages?
[JOT 2015;29:121–129]
- Anterior (Smith-Peterson)
- Advantage
- Excellent exposure of anterior femoral neck and subcapital region
- Disadvantage
- Second lateral incision needed for internal fixation
- Anterolateral (Watson-Jones)
- Second lateral incision needed for internal fixation
- Advantage
- Single incision
- Disadvantage
- Limited subcapital exposure
What are the indications for cannulated screws and SHS in femoral neck fractures?
[JOT 2015;29:121–129]
- Garden I and II
* Cannulated screws or SHS - Garden III and IV
- Closed reduction with anatomical alignment, assess Pauwels angle
- Pauwel’s type I and II = cannulated screws or SHS
- Pawuel’s type III = SHS
- Comminution and basicervical = SHS
Based on the FAITH trial which construct (cannulated screws vs DHS) results in less reoperation within the first 24 months?
Neither, equal reoperation between cannulated screws and SHS
Based on the FAITH trial which subgroups may benefit from SHS (vs cannulated screws)?
- Smokers
- Basicervical fractures
- Displaced fractures
What is one disadvantage of SHS shown in the FAITH trial compared to cannulated screws?
Higher risk of AVN (9% vs. 5%)
What are the technical points for the placement of cannulated screws for femoral neck fracture?
[JOT 2015;29:121–129]
- 3 cannulated screws (6.5, 7.0 or 7.3mm)
- Parallel inverted triangle configuration
- Inferior – along calcar, resists inferior displacement
- Posterosuperior – resists posterior displacement
- Anterosuperior
- Start point for the inferior screw should be at or above the LT
- Screw threads should be entirely within the head fragment and within 5mm of subchondral bone
What modifications can be made to the cannulated screw construct to enhance fixation (in femoral neck)?
[JOT 2015;29:121–129][Eur J Orthop Surg Traumatol (2016) 26:355–363]
- 4th screw along posterior cortex in setting of posterior comminution
- Add washers in osteoporotic bone to prevent penetration through lateral cortex and enhance lag effect
- Parallel or divergent screws (avoid convergent)
- Trochanteric lag screw in high risk patterns (high Pauwels angle)
- Inferomedial buttress plate
What are the advantages of a derotation screw when using a SHS?
[Eur J Orthop Surg Traumatol (2016) 26:355–363]
- Protect against rotation/displacement and risk of AVN
- Biomechanically stronger
What is the tip-apex distance and the calcar referenced tip-apex distance – what is the significance?
[J Orthop Surg Res. 2018; 13: 106]
- TAD = sum of the distances from the tip of the lag screw to the apex of the femoral head on AP and lateral radiographs
- CalTAD = sum of a TAD in the lateral view and the distance, in the AP view, between a line tangent to the medial cortex of the femoral neck and the tip of the lag screw
* TAD >25mm, CalTAD >25 and combined TAD and CalTAD >50mm increase the risk of lag screw mobilization and cutout
What is the management of femoral neck nonunion after ORIF?
[JOT 2006;20:485–491]
- Elderly patient
* Total hip arthroplasty or hemiarthroplasty - Young patient
- Valgus intertrochanteric osteotomy with blade plate (Pauwels)
- Converts shear forces into compressive forces
- Valgus intertrochanteric osteotomy with sliding hip screw (contemporary)
- Potential advantages
- Reaming creates local autograft
- Sliding screw maximizes compression
- Less technically demanding than blade plate
- Disadvantages
- Greater bone removal
- Less rotational control of the proximal segment
- Potential advantages
What are the steps in performing valgus intertrochanteric osteotomy for femoral neck nonunion?
[JOT 2006;20:485–491]
- Determine the osteotomy angle
- Goal = fracture plane less than 30°
- Osteotomy angle = current angle minus the goal angle
- Advance the guide pin into the femoral head
* Ream, tap and advance the lag screw - The superior limb of the closing wedge osteotomy starts just below the lag screw (perform first)
* Ends half way across the width of the femur as it intersects the inferior limb - The inferior limb of the closing wedge osteotomy passes just below the LT
* Do not complete medial aspect of osteotomy until the side plate is attached - Attach side plate to the lag screw
- Complete the inferior limb osteotomy medially and use the side plate to rotate the proximal femur fragment into valgus
- Use the compression screw of the SHS and fix the side plate with cortical screws
What are Kaufer’s five variables affecting the biomechanical strength of repair in intertrochanteric hip fractures?
- Surgeon-independent variables
- Bone quality
- Fracture pattern or fracture stability
- Surgeon-dependent variables
- Implant choice
- Quality of fracture reduction
- Positioning of the implant
What are the characteristics of stable intertrochanteric hip fractures?
[J Orthop Trauma 2015;29:S4–S9]
- Resist displacement after adequate reduction and fixation
- Includes:
* 2-part intertroch fractures with intact posteromedial buttress - Treated with either IM device or SHS
What are characteristics of unstable intertrochanteric hip fractures?
[J Orthop Trauma 2015;29:S4–S9]
- Tend to collapse after adequate reduction and internal fixation
- Includes:
- Posteromedial comminution
- Reverse obliquity
- Subtrochanteric extension
- Lateral wall comminution (reverse obliquity equivalent)
- Reverse oblique variant
- Fracture orientation when viewed on AP looks typical, however on the lateral the fracture extends from proximal-anterior to distal-posterior
- Treated with IM device (ie. Contraindications for SHS)
If a SHS is used and a lateral wall blowout is identified or caused iatrogenically, what are the surgical options?
[JAAOS 2016;24:e50-e58]
- SHS with the addition of a trochanteric stabilization plate
- Conversion to a cephalomedullary nail
What is an acceptable range of neck-shaft angle compared to the patient’s opposite side (in intertrochanteric hip fractures)?
[J Am Acad Orthop Surg 2004;12:179-190]
5o of Varus to 20o of Valgus
- valgus is more acceptable as it reduces the bending stress on the implant and may offset the shortening that occurs with fragment impaction
What is the optimal position of the lag screw for SHS?
- Center-center in the femoral neck
* Avoid anterior/superior placement and posterior/inferior placement - ‘Deep’ on AP and lateral
* IE. Tip-Apex distance <25mm
What are the advantages of an intramedullary sliding hip screw (i.e nail) vs. a standard SHS in intertrochanteric hip fractures?
[J Am Acad Orthop Surg 2004;12:179-190]
- Closed, percutaneous
- Minimizes fracture zone insult
- Reduces perioperative blood loss
- Decreased bending moment on the lag screw (shorter lever arm)
- Intramedullary buttress prevents femoral shaft medialization
How can anterior cortical abutment or perforation be avoided when using a long cephomedullary nail?
[JAAOS 2016;24:e50-e58]
- Anterior cortical perforation secondary to a nail-femoral bow mismatch is a complication unique to long nails
- Ways to prevent include:
- Avoid posterior GT entry point
- Accept only a central or slightly posterior position of the guidewire in the canal distally
- Use a shorter nail in an excessively bowed femur
- Avoid overreaming or eccentric reaming
- Leave the guidewire in place until the nail is fully seated
- Use a smaller diameter nail
What are the disadvantages of long nails versus short nails in the management of intertrochanteric fractures?
[JAAOS 2016;24:e50-e58]
- Longer surgical time
* Due to time for reaming and free hand distal locking screw - Increased blood loss and higher incidence of transfusions
- Higher cost
- Distal femur metaphyseal fracture
* Unique to long nails as stress riser is distal
What are the indications of a long nail over a short nail in intertrochanteric hip fractures?
[JAAOS 2016;24:e50-e58]
- Reverse obliquity fractures – AO/OTA 31-A3
- Subtrochanteric extension – AO/OTA 31-A2.3
* Extension >1cm below the LT - Capacious proximal canal
* Short nails will result in toggle and an overall varus alignment - Pathological fractures
What are the surgical options in the event of a diaphyseal femoral fracture with a short cephalomedullary nail in place?
[JAAOS 2016;24: e50-e58]
- Early – convert to long nail
- Late – plate osteosynthesis
What is the Z-effect and reverse Z-effect complication (in context of intertrochanteric hip fracture)?
[Patient Safety in Surgery 2011, 5:17]
- Unique complication when treating intertrochanteric fractures with IM nails and two proximal lag screws (eg. recon nail)
- Z-effect =
- Lateral migration of the inferior screw
- Varus collapse
- Perforation of the femoral head by the superior screw
- Reverse Z-effect =
- Lateral migration of the superior screw
- Medial migration of the inferior screw
What is the consequence of shaft medialization in fixation of interrtochanteric hip fractures?
- Decreases femoral offset
- Decreases abductor muscle efficiency
- Increases joint reactive forces
- Valgus knee alignment
What is the definition of the subtrochanteric region?
Area extending 5cm below the lesser trochanter
What are the deforming forces on the proximal fragment in a subtrochanteric femur fracture?
- Abduction – gluteus medius and minimus
- Flexion – iliopsoas
- External rotation – short external rotators
What are the deforming forces on the distal fragment in a subtrochanteric femur fracture?
Adduction and shortening – adductors
What is the Russel-Taylor classification for subtrochanteric fractures?
Type I – spare the piriformis fossa
Type II – involve the piriformis fossa
Subclassified as A or B
- Type A do not involve the lesser trochanter
- Type B do involve the lesser trochanter
*** Historically used to differentiate between fractures that would amenable to an IM nail (type I) and those that required some form of a lateral fixed angle device (type II)
- Current interlocking options with both trochanteric and piriformis entry nails allow for treatment of type II fractures with intramedullary implants
What is the most common malunion following fixation of subtrochanteric fractures?
Varus and flexion (procurvatum)
What are techniques to avoid varus malreduction when nailing a subtrochanteric fracture?
[JOT 2018;32:e151–e156)][JOT 2015;29:S28–S33]
- Slight medialization of start point with a trochanteric nail
* Also leads to less abductor damage - Joysticks
- Femoral distractor
- Finger reduction tool (spoon)
- Blocking screws
- Schanz pins
- Clamps
- Lateral decubitus position neutralizes deforming forces
- Unicortical plating
What is the blood supply to the femur?
[Rockwood and Green 8th ed. 2015]
- Medullary
* 1-2 nutrient vessels arising from the profunda femoral artery and entering the proximal ½ of the femur posteriorly at the linea aspera - Periosteal
What is the classification system for femoral shaft fractures?
[Rockwood and Green 8th ed. 2015]
- Winquist and Hansen system
- Based on the percentage of intact femoral shaft at the fracture site
- Grade 0
- No comminution
- Grade I
- ≥75% cortical contact
- Small butterfly fragment or minimal comminution <25%
- ≥75% cortical contact
- Grade II
- ≥50% cortical contact
- Butterfly fragment or comminution 25-50%
- ≥50% cortical contact
- Grade III
- Minimal cortical contact
- Butterfly fragment or comminution 50-75%
- Minimal cortical contact
- Grade IV
- No cortical contact
- Complete cortical comminution
- Segmentally comminuted
2. AO-OTA classification
- No cortical contact
- Type A – simple
- Type B – wedge
- Type C – complex
What are the indications for a retrograde nail in a femoral shaft fracture?
- Ipsilateral femoral neck fracture
- Ipsilateral acetabular fracture
- Distal femur fracture
- Bilateral femur fracture
- Multisystem trauma
- Floating knee
- Obesity/pregnancy
* Relative contraindication for antegrade nail
What are the IMN start points?
- Antegrade – depends on nail
* Both GT and piriformis fossa are acceptable - Retrograde
- Anatomically
- 1.2cm anterior to the femoral PCL insertion and centered in the intercondylar notch [JOT 2015]
- Radiographically
- Midline (or just medial) in intercondylar notch and just anterior to Blumensaats line
What are the advantages of reaming for femur IM nails?
- Allows for larger stiffer nail to be passed
- Increases the length of the isthmus
* Increasing bone-nail contact, thereby increasing stiffness - Autograft bone
What are the disadvantages of reaming for femur IM nails?
- It increases the length of the surgical procedure
- It may increase the chance of pulmonary fat emboli
- It can create heat necrosis
- It temporarily destroys part of the endosteal blood supply.
What are techniques to limit fat emboli syndrome/appropriate reaming technique/minimize intramedullary pressure (femoral shaft fracture)?
[J Orthop Trauma 2009;23:S12–S17]
- Sharp reamers
- Narrow reamer shaft
- Long lead head taper
- Enlarged cutting flutes
- Flexible shaft
- Slow driving speed
- High revolution
- Venting
- Reamer-irrigator-aspirator (RIA)
- Hollow reamers
- Over-ream compared to size of nail
What are the advantages and disadvantages of using a fracture table for nailing diaphyseal femur fractures?
[JAAOS 2017;25:e251-e260][JBJS 2002;84(9):1514-1521]
Advantages
- Fewer assistants
- Easier femoral head and neck imaging
- Better if thoracic trauma
Disadvantages
- Longer setup
- Nerve palsies
- Pudendal, femoral, sciatic
- Compartment syndrome in the contralateral leg
- Decreased access to other body parts
- Increased internal malrotation >10o
What are advantages and disadvantages of the lateral decubitus position (vs. supine) for nailing diaphyseal femur fractures?
[JAAOS 2017;25:e251-e260]
Advantages
- Easier access to proximal femur
- Easier start point access in larger patients
- Reduces sagittal plane deformity of the distal fragment in relation to the proximal fragment in a proximal diaphyseal shaft fracture
Disadvantages
- Unfamiliarity with positioning
- Pulmonary complications in patients with lung injuries
- Difficulty obtaining lateral images of the proximal femur
- Increased risk of angular or rotational malalignment
- Requires repositioning for bilateral femur nailing
What are methods for assessing restoration of length in diaphyseal femur fracture nailing?
[JAAOS 2017;25:e251-e260]
Measure contralateral femur length from starting point to distal physeal scar using a extra-medullary ruler or sterile IM nail
What are methods for assessing restoration of rotation in diaphyseal femur fracture nailing?
[JAAOS 2017;25:e251-e260]
- Assess the LT profile in comparison to the contralateral side
* Take a perfect lateral of the knee or an AP with patella centered over the distal femur then take an AP of the hip - Key in fracture fragments
- Cortical thickness
- Diameter difference between proximal and distal fragment
- Clinical comparison of contralateral leg rotation (hip IR and ER)
- Inherent anteversion built into the nail [J Orthop Trauma 2014;28:e34–e38)]
* By centering the proximal locking screws in the femoral head and aligning the distal locking screws with the femoral condylar axis, the proximal and distal fracture fragments are positioned in the same anteversion inherent to the nail construct - Fluoroscopic measurement of anteversion [JAAOS 2011;19:17-26]
- Assess uninjured side first
- True lateral view of the proximal femur followed by true lateral of ipsilateral knee
- The difference in angles of the fluoro between the two measurements determines the version
What are the deforming forces on the distal fragment in femur diaphyseal fractures?
[JAAOS 2017;25:e251-e260]
- Apex medial due to tension of IT band
- Apex posterior due to tension of gastrocnemius
What are reduction techniques for diaphyseal femur fracture nailing?
[JAAOS 2017;25:e251-e260]
- Traction
- Fracture table
- Skeletal traction (distal femur or proximal tibia)
- Manual traction
- Noninvasive reduction techniques
- Stack of towels in apex posterior deformity
- Radiolucent triangle in distal fractures to relax the gastrocs
- Pushing reduction force (eg. mallet)
- Pulling reduction force (eg. towel or laporotomy sponge)
- F-tool
- Medullary femoral reduction tool (ie. Reduction spoon)
- Percutaneous reduction techniques (stab incisions)
- Spiked-ball pusher
- Shoulder hook
- Fracture reduction clamps
- External fixation half pins
- Blocking screws
- Placed on concave side in the mobile segment
- Open reduction (direct lateral subvastus approach)
- Placed on concave side in the mobile segment
- Bone reduction forceps
- Plating with unicortical screws
What assessments should be made prior to completion of femur nailing?
[JAAOS 2017;25:e251-e260]
- Confirm acceptable length, alignment and rotation
- Femoral neck fracture ruled out by fluoro
- Knee ligament examination
- Assess compartments
What are the described traction table-related complications?
[JAAOS 2010;18:668-675]
- Malrotation and malalignment
- Increased incidence of femoral malrotation >10°
- Compared to manual traction
- Misjudging start point in obese patients results in varus/valgus malalignment
- Neurological injury
- Pudendal nerve injury due to perineal post
- Results in perineal dysesthesia and/or erectile dysfunction
- Sciatic nerve injury in the well leg
- Due to hemilithotomy position with hip flexed to 90° and knee flexed to <90°
- Common peroneal nerve injury in the well leg
- Due to hemilithotomy position compression against leg holder or compression due to straps/wraps
- Perineal soft tissue injury
- Due to hemilithotomy position compression against leg holder or compression due to straps/wraps
- Due to compression against the perineal post (can cause necrosis)
4. Compartment syndrome - Occurs in well leg due to the hemilithotomy position
- Direct calf compression and vascular hypoperfusion
What are ways to reduce the risk of traction table-related complications?
[JAAOS 2010;18:668-675]
- Use a flat top table and free extremity draping in the obese patient
- Perineal post should be placed between the genitalia and the contralateral leg
- Use a well padded, large diameter (>10cm) perineal post
- Avoid adduction of the leg across neutral
- Avoid well leg hemilithotomy position
- Limit traction time
* If traction time >2 hours release the traction
What imaging should be obtained and reviewed in the perioperative management of a femoral shaft fracture to reduce the chance of missed femoral neck fractures?
[Rockwood and Green 8th ed. 2015]
- Obtain preoperative hip xrays
- If CT obtained for abdominal/pelvic injuries review for hip fracture
- Obtain intraoperative fluoro images before nailing
- Obtain intraoperative fluoro images after nailing with the hip in 10-15 degrees of internal rotation
- Obtain postoperative hip radiographs prior to leaving the operating room
In what percentage of femoral shaft fractures does an ipsilateral femoral neck fracture occur?
[JAAOS 2018;26:e448-e454]
2-9%
In what percentage of ipsilateral femoral neck and shaft fractures is the femoral neck fracture missed?
[JAAOS 2018;26:e448-e454]
- Historically, up to 30%
- Recently, 6-22%
In ipsilateral femoral neck and shaft fractures – who is the typical patient and what is the typical femoral shaft and neck fracture?
[JAAOS 2018;26:e448-e454]
- Typical patient:
- Avg age is 35
- 75% are male
- Typical femur fracture
- Comminuted, middle 1/3
- Open in 15-33% of cases
- Typical femoral neck fracture
* Basicervical, vertically oriented and undisplaced in 60% of cases - Associated injuries
- 75-100% have multisystem injuries
- 20-40% have ipsilateral knee injuries
- Ligamentous injury
- Tibial plateau fracture
- Patella fracture
- Knee dislocation
What is the commonly described mechanism for ipsilateral femoral neck and shaft fractures?
[JAAOS 2018;26:e448-e454]
“Dashboard” Injury
- Axial force creates mid-shaft comminuted fracture
- If hip is abducted, femoral neck or acetabular fracture can occur
- Posterior hip dislocation if adducted
What is the Tornetta protocol (2007) for diagnosing ipsilateral femoral neck fractures in the context of a femoral shaft fracture?
[JAAOS 2018;26:e448-e454]
- AP internal rotation radiograph of the hip
- Fine-cut (2-mm) CT scan through the femoral neck
- Intraoperative fluoroscopic lateral view of the hip
- Postoperative AP and lateral radiographs of the hip in the operating room
* Outcomes:*
- Reduced rate of delay in diagnosis by 91%
- Cannada study (2009) - 2mm CT scan missed 18% of ipsilateral femoral neck fractures
What is the recommended management of a combined femoral shaft and hip fracture?
[Rockwood and Green 8th ed. 2015] [JAAOS 2018;26:e448-e454]
[Rockwood and Green 8th ed. 2015]
- 2 constructs
- Fix the hip fracture first
- Subcapital and transcervical with mutiple lag screws
- Cannulated screws
- Basicervical and intertrochanteric with sliding hip screw
- Fix the femoral shaft second
- Usually retrograde nail
- Lateral plating also acceptable
[JAAOS 2018;26:e448-e454]
- Once a femoral shaft fracture is diagnosed, get AP pelvis and AP/lateral hip XRs
- If a CT of the pelvis is ordered for other reasons, this is reviewed as a “free look” at the femoral neck
- Do not routinely order a CT solely to evaluate the femoral neck
- If displaced femoral neck fracture:
- ORIF of femoral neck with SHS or cannulated screws
- Open reduction through anterior approach
- Lateral appraoch for fixation
- Screws/fixation placed in the posterior
half of the shaft so retrograde nail can pass anterior to them
- Femoral shaft fracture is then reduced, and a retrograde femoral nail is placed with the tip of
the nail passing anterior to the screws of the proximal implant
3 Femoral shaft fracture without a femoral neck fracture diagnosed preoperatively:
- Intraop assessment of the femoral neck with fluoroscopy in OR, with beam angled 10o to visualize the neck in profile
- If a neck fracture is identified, use 2-implant fixation with closed reduction of neck
- If no neck fracture is identified, a CM nail with two proximal interlocking screws placed across the femoral neck is used
Notes:
- Most important factors related to femoral neck union is quality of reduction
- Treatment with an antegrade nail with cannulated screws adjacent to the nail is typically used only in patients with a neck fracture that is identified intraoperatively after nail insertion
- Neck screws are placed anterior to nail
- If anterior and posterior screws are attempted,
an iatrogenic subtrochateric fracture can occur
What are the complications associated with treatment of ipsilateral femoral neck and shaft fractures?
[JAAOS 2018;26:e448-e454]
- Femoral neck
- Nonunion 5%, Malunion 5%
- Both lower than those for isolated femoral neck fractures
- Risk factors for nonunion/AVN:
- Delay in the diagnosis of the femoral neck fracture
- Amount of initial displacement
- Malreduction at the time of fixation
- Femoral shaft
- Nonunion - up to 20%
- Higher than the rates reported for isolated femoral shaft fractures
- Due to higher energy injuries that have a higher proportion of open fractures compared with isolated femoral shaft fractures
- Open fracture is the greatest risk factor for nonunion of the femoral shaft component
What is the incidence of femoral malrotation following IMN?
[JAAOS 2011;19:17-26]
Up to 27.6% (range 2.3-27.6%)
Which malrotation is more poorly tolerated?
[JAAOS 2011;19:17-26]
External malrotation