Trauma - Femur/Tibia Flashcards

Question 1

Q

Per the Lower Extremity Assessment Project (LEAP) study, what were theoutcomes of amputation vs limb salvage?

[JAAOS 2011;19(suppl 1):S20-S22]

Answer

A

No difference in outcomes with amputation versus limb salvage at 2- and 7-year followup

Question 2

Q

Per the LEAP study, what factors influenced outcomes of amputation/limb salvage?

[JAAOS 2011; 19(suppl 1): S20-S22]

Answer

A

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

Question 3

Q

Per the LEAP study, what is the difference in cost for amputation vs limb salvage?

[JBJS 2010;92:2852-68]

Answer

A

The lifetime cost for the amputation group was estimated to be about three times higher secondary to prosthesis-related expenses

Question 4

Q

Per the LEAP study, what role should an insensate foot play in deciding between amputation vs limb salvage?

[JBJS 2010;92:2852-68]

Answer

A

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

Question 5

Q

What are the indications for lower extremity amputation following lower extremity trauma?

[JBJS 2010;92:2852-68]

Answer

A

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

Question 6

Q

What is the blood supply to the femoral head?

[JAAOS 2016;24:515-526]

Answer

A

Primary = medial femoral circumflex artery

Femoral artery → profunda femoris artery → medial femoral circumflex artery → ascending branch → deep branch

Question 7

Q

What is the Garden Classification of femoral neck fractures based on AP?

Answer

A

Type I – incomplete, valgus impacted

Type II – complete, nondisplaced

Type III – complete, partial displacement

Type IV – complete, full displacement

Question 8

Q

What is the Simplified Garden Classification for femoral neck fractures?

Answer

A

Nondisplaced = Garden I and II
Displaced = Garden III and IV

Question 9

Q

What is Pauwel’s classification of femoral neck fractures?

Answer

A

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

Question 10

Q

What are signs of adequate femoral neck reduction?

Answer

A

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

Question 11

Q

What are the techniques for closed reduction of a femoral neck fracture to obtain anatomical alignment?

Answer

A

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

Question 12

Q

What residual deformity following femoral neck reduction is not acceptable?

[JOT 2015;29:121–129]

Answer

A

Varus angulation
Inferior offset
Retroversion

***These 3 factors increase the risk of nonunion, loss of reduction and osteonecrosis

Question 13

Q

In the young patient, what means of anatomical reduction is preferred – open vs. closed?

[JOT 2015;29:121–129]

Answer

A

Both are acceptable as long as anatomical reduction achieved
If closed unsuccessful proceed to open reduction

Question 14

Q

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]

Answer

A

Anterior (Smith-Peterson)

Advantage
- Excellent exposure of anterior femoral neck and subcapital region
Disadvantage
- Second lateral incision needed for internal fixation
  1. Anterolateral (Watson-Jones)
Advantage
- Single incision
Disadvantage
- Limited subcapital exposure

Question 15

Q

What are the indications for cannulated screws and SHS in femoral neck fractures?

[JOT 2015;29:121–129]

Answer

A

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

Question 16

Q

Based on the FAITH trial which construct (cannulated screws vs DHS) results in less reoperation within the first 24 months?

Answer

A

Neither, equal reoperation between cannulated screws and SHS

Question 17

Q

Based on the FAITH trial which subgroups may benefit from SHS (vs cannulated screws)?

Answer

A

Smokers
Basicervical fractures
Displaced fractures

Question 18

Q

What is one disadvantage of SHS shown in the FAITH trial compared to cannulated screws?

Answer

A

Higher risk of AVN (9% vs. 5%)

Question 19

Q

What are the technical points for the placement of cannulated screws for femoral neck fracture?

[JOT 2015;29:121–129]

Answer

A

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

Question 20

Q

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]

Answer

A

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

Question 21

Q

What are the advantages of a derotation screw when using a SHS?

[Eur J Orthop Surg Traumatol (2016) 26:355–363]

Answer

A

Protect against rotation/displacement and risk of AVN
Biomechanically stronger

Question 22

Q

What is the tip-apex distance and the calcar referenced tip-apex distance – what is the significance?

[J Orthop Surg Res. 2018; 13: 106]

Answer

A

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

Question 23

Q

What is the management of femoral neck nonunion after ORIF?

[JOT 2006;20:485–491]

Answer

A

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

Question 24

Q

What are the steps in performing valgus intertrochanteric osteotomy for femoral neck nonunion?

[JOT 2006;20:485–491]

Answer

A

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

Question 25

Q

What are Kaufer’s five variables affecting the biomechanical strength of repair in intertrochanteric hip fractures?

Answer

A

Surgeon-independent variables

Bone quality
Fracture pattern or fracture stability

Surgeon-dependent variables

Implant choice
Quality of fracture reduction
Positioning of the implant

Question 26

Q

What are the characteristics of stable intertrochanteric hip fractures?

[J Orthop Trauma 2015;29:S4–S9]

Answer

A

Resist displacement after adequate reduction and fixation
Includes:
* 2-part intertroch fractures with intact posteromedial buttress
Treated with either IM device or SHS

Question 27

Q

What are characteristics of unstable intertrochanteric hip fractures?

[J Orthop Trauma 2015;29:S4–S9]

Answer

A

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)

Question 28

Q

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]

Answer

A

SHS with the addition of a trochanteric stabilization plate
Conversion to a cephalomedullary nail

Question 29

Q

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]

Answer

A

5^o of Varus to 20^oof Valgus

valgus is more acceptable as it reduces the bending stress on the implant and may offset the shortening that occurs with fragment impaction

Question 30

Q

What is the optimal position of the lag screw for SHS?

Answer

A

Center-center in the femoral neck
* Avoid anterior/superior placement and posterior/inferior placement
‘Deep’ on AP and lateral
* IE. Tip-Apex distance <25mm

Question 31

Q

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]

Answer

A

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

Question 32

Q

How can anterior cortical abutment or perforation be avoided when using a long cephomedullary nail?

[JAAOS 2016;24:e50-e58]

Answer

A

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

Question 33

Q

What are the disadvantages of long nails versus short nails in the management of intertrochanteric fractures?

[JAAOS 2016;24:e50-e58]

Answer

A

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

Question 34

Q

What are the indications of a long nail over a short nail in intertrochanteric hip fractures?

[JAAOS 2016;24:e50-e58]

Answer

A

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

Question 35

Q

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]

Answer

A

Early – convert to long nail
Late – plate osteosynthesis

Question 36

Q

What is the Z-effect and reverse Z-effect complication (in context of intertrochanteric hip fracture)?

[Patient Safety in Surgery 2011, 5:17]

Answer

A

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

Question 37

Q

What is the consequence of shaft medialization in fixation of interrtochanteric hip fractures?

Answer

A

Decreases femoral offset
Decreases abductor muscle efficiency
Increases joint reactive forces
Valgus knee alignment

Question 38

Q

What is the definition of the subtrochanteric region?

Answer

A

Area extending 5cm below the lesser trochanter

Question 39

Q

What are the deforming forces on the proximal fragment in a subtrochanteric femur fracture?

Answer

A

Abduction – gluteus medius and minimus
Flexion – iliopsoas
External rotation – short external rotators

Question 40

Q

What are the deforming forces on the distal fragment in a subtrochanteric femur fracture?

Answer

A

Adduction and shortening – adductors

Question 41

Q

What is the Russel-Taylor classification for subtrochanteric fractures?

Answer

A

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

Question 42

Q

What is the most common malunion following fixation of subtrochanteric fractures?

Answer

A

Varus and flexion (procurvatum)

Question 43

Q

What are techniques to avoid varus malreduction when nailing a subtrochanteric fracture?

[JOT 2018;32:e151–e156)][JOT 2015;29:S28–S33]

Answer

A

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

Question 44

Q

What is the blood supply to the femur?

[Rockwood and Green 8th ed. 2015]

Answer

A

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

Question 45

Q

What is the classification system for femoral shaft fractures?

[Rockwood and Green 8th ed. 2015]

Answer

A

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%
Grade II
- ≥50% cortical contact
  - Butterfly fragment or comminution 25-50%
Grade III
- Minimal cortical contact
  - Butterfly fragment or comminution 50-75%
Grade IV
- No cortical contact
  - Complete cortical comminution
  - Segmentally comminuted
    2. AO-OTA classification
Type A – simple
Type B – wedge
Type C – complex

Question 46

Q

What are the indications for a retrograde nail in a femoral shaft fracture?

Answer

A

Ipsilateral femoral neck fracture
Ipsilateral acetabular fracture
Distal femur fracture
Bilateral femur fracture
Multisystem trauma
Floating knee
Obesity/pregnancy
* Relative contraindication for antegrade nail

Question 47

Q

What are the IMN start points?

Answer

A

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

Question 48

Q

What are the advantages of reaming for femur IM nails?

Answer

A

Allows for larger stiffer nail to be passed
Increases the length of the isthmus
* Increasing bone-nail contact, thereby increasing stiffness
Autograft bone

Question 49

Q

What are the disadvantages of reaming for femur IM nails?

Answer

A

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.

Question 50

Q

What are techniques to limit fat emboli syndrome/appropriate reaming technique/minimize intramedullary pressure (femoral shaft fracture)?

[J Orthop Trauma 2009;23:S12–S17]

Answer

A

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

Question 51

Q

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]

Answer

A

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 >10^o

Question 52

Q

What are advantages and disadvantages of the lateral decubitus position (vs. supine) for nailing diaphyseal femur fractures?

[JAAOS 2017;25:e251-e260]

Answer

A

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

Question 53

Q

What are methods for assessing restoration of length in diaphyseal femur fracture nailing?

[JAAOS 2017;25:e251-e260]

Answer

A

Measure contralateral femur length from starting point to distal physeal scar using a extra-medullary ruler or sterile IM nail

Question 54

Q

What are methods for assessing restoration of rotation in diaphyseal femur fracture nailing?

[JAAOS 2017;25:e251-e260]

Answer

A

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

Question 55

Q

What are the deforming forces on the distal fragment in femur diaphyseal fractures?

[JAAOS 2017;25:e251-e260]

Answer

A

Apex medial due to tension of IT band
Apex posterior due to tension of gastrocnemius

Question 56

Q

What are reduction techniques for diaphyseal femur fracture nailing?

[JAAOS 2017;25:e251-e260]

Answer

A

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
  1. Open reduction (direct lateral subvastus approach)
Bone reduction forceps
Plating with unicortical screws

Question 57

Q

What assessments should be made prior to completion of femur nailing?

[JAAOS 2017;25:e251-e260]

Answer

A

Confirm acceptable length, alignment and rotation
Femoral neck fracture ruled out by fluoro
Knee ligament examination
Assess compartments

Question 58

Q

What are the described traction table-related complications?

[JAAOS 2010;18:668-675]

Answer

A

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
  1. Perineal soft tissue injury
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

Question 59

Q

What are ways to reduce the risk of traction table-related complications?

[JAAOS 2010;18:668-675]

Answer

A

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

Question 60

Q

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]

Answer

A

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

Question 61

Q

In what percentage of femoral shaft fractures does an ipsilateral femoral neck fracture occur?

[JAAOS 2018;26:e448-e454]

Question 62

Q

In what percentage of ipsilateral femoral neck and shaft fractures is the femoral neck fracture missed?

[JAAOS 2018;26:e448-e454]

Answer

A

Historically, up to 30%
Recently, 6-22%

Question 63

Q

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]

Answer

A

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

Question 64

Q

What is the commonly described mechanism for ipsilateral femoral neck and shaft fractures?

[JAAOS 2018;26:e448-e454]

Answer

A

“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

Answer 64

A

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

Answer 65

A

[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 10^o 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

Answer 66

A

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

Answer 67

A

Up to 27.6% (range 2.3-27.6%)

Answer 68

A

External malrotation

Answer 69

A

Transverse
Segmental
comminuted
Bone loss

Answer 70

A

Proximal femur fractures = internal malrotation
Distal femur fractures = external malrotation

Answer 71

A

Internal malrotation = fracture table
External malrotation = supine/free-leg/lateral bump position

Answer 72

A

Angle between a line drawn through the center of the femoral neck and a tangent drawn across the posterior aspect of the distal femoral condyles

Answer 73

A

No universally accepted guidelines exist for defining the degree at which malrotation becomes significant
Intervene when patient determines malrotation to be functionally or cosmetically unacceptable

Answer 74

A

CT rotational profile

Answer 75

A

Prior to union

Remove distal locking screw and correct rotation
If correction is <20° distal screw cutout is a concern, consider using alternate locking holes

Following union

Remove nail
Perform transverse osteotomy
Correct rotation and reinsert nail and locking screws

Rotation correction

Can be achieved by placing Steinmann pins in trochanteric region and distal femoral region prior to nail removal
Angle of correction can be measured with goniometer relative to the pins

Answer 76

A

Diphosphonate-related fracture

Answer 77

A

Major

No or minimal trauma
Fracture originates at the lateral cortex and is substantially transverse in orientation
Complete fractures may be associated with a medial spike
No or minimal comminution
Thickening of the lateral cortex (beaking)

Minor

Generalized increase in cortical thickness of the femoral diaphysis
Unilateral or bilateral prodromal symptoms
Bilateral incomplete or complete femoral diaphyseal fractures
Delayed fracture healing

Answer 78

A

When the T-score ≤-2.5 at the femoral neck or spine

Answer 79

A

Binds to hydroxyapatite crystals

Results in:
- Decreased osteoclast function
- Induces osteoclast apoptosis
- Inhibit bone resorption

Answer 80

A

High risk patient

Hip T score ≤ -2.5, previous fracture of the hip or spine or ongoing high dose steroid therapy
Drug holiday not justified

Moderate risk patient

(Hip T score> -2.5 and no prior hip or spine fracture)
Consider drug holiday after 3-5 years of alendronate, risedronate or zoledronic acid therapy

Low risk patient

(Did not meet criteria for treatment at time of treatment initiation)
Discontinue therapy

Answer 81

A

Osteonecrosis of the jaw
Atypical femur fractures
Atrial fibrillation
GI intolerance
Hypocalcemia
Flu-like symptoms
* Acute phase reaction with monthly dosing
Inflammatory eye disorders

Answer 82

A

Discontinue diphosphonate therapy and consult endocrinology
Assess Vitamin D and calcium intake and supplement as needed
Evaluate the contralateral femur for atypical fractures
* Consider radiographs, MRI, CT, bone scan
Surgery for incomplete and complete atypical femur fractures

Although nonsurgical can be attempted for incomplete fractures the outcomes are poor
- Intractable pain, complete fracture
IM nailing preferred
Bilateral atypical fractures
- Decision of single vs. staged fixation is patient dependent

Answer 83

A

Endocrinology referral for teriparatide

Recombinant form of parathyroid hormone (PTH)

Answer 84

A

Gastrocnemius
* Cause extension of the distal fragment (apex posterior)
Hamstrings, quadriceps and adductors
* Cause shortening and varus

Answer 85

A

Anterior proximal to patella with variable degree of quadriceps tendon injury

Answer 86

A

OTA

A – extra-articular
- (1) simple
- (2) metaphyseal wedge
- (3) metaphyseal complex (comminuted)
B – partial articular
- (1) lateral condyle sagittal
- (2) medial condyle sagittal
- (3) coronal (Hoffa)
C – complete articular
- (1) articular and metaphyseal simple
- (2) articular simple/metaphyseal complex
- (3) articular complex

Answer 87

A

Lateral condyle

Answer 88

A

Letenneur classification

3 types based on distance from the posterior cortex of the femur shaft
- Type 1 – fracture parallel to the posterior cortex
- Type 2 – fracture posterior to the posterior cortex of variable size
- Type 3 – oblique fracture

Answer 89

A

Trapezoidal-shape viewed end on

Posterior wider than anterior
25° inclination on medial surface
15° inclination on lateral surface

Answer 90

A

Anatomic reduction of articular surface
Restore length, alignment and rotation
Stable internal fixation
Early ROM
Delayed protected WB

Answer 91

A

Lateral approach (most common)

Lateral incision centred distally over the lateral epicondyle
- Incise fascia lata
- Sub-vastus lateralis
Limited visualization of the intercondylar notch and medial condyle

Anterolateral approach (“Swashbuckler”) [JOT 1999; 13(2): 138-140]
* Midline incision curved slightly laterally proximally
- Fascia is split inline with incision and elevated off underlying vastus lateralis
- IT band is retracted laterally
- Lateral parapatellar arthrotomy is made
- Vastus lateralis is separated from the intermuscular septum and IT band
- Retractor is placed under the quadriceps muscle elevating them off the femur medially and everting the patella medially
  * Provides excellent articular exposure
- Exposes distal femur
- Minimal quads disruption
- Incision can be used in future TKA
Lateral mini-invasive

MIPO/LISS systems
- Fixation of condyle through incision
- Plate passed proximally with screws through stab incisions

Medial approach

Answer 92

A

OTA A

Lateral periarticular locking plate (lateral approach)
Minimally invasive locked plate
Retrograde nail (locked)

OTA B

Lateral or medial condyle sagittal fracture
- Buttress plating
Coronal fracture (Hoffa)
- A-P countersunk screws
- Small or mini-frag buttress plate
  - If nonarticular apex present
    3. OTA C
Anterolateral approach for anatomic reduction and fixation of articular surface followed by lateral locking plate
Minimally invasive locking plate or retrograde nail can also be used

Answer 93

A

Medullary (inner 70-75%)

Derived from the main nutrient artery
- Branch of posterior tibial artery
  - Enters tibia in proximal 1/3

Periosteal (outer 25-30%)

Answer 94

A

AO/OTA classification

A - simple fractures
B - wedge fractures
C - complex fractures

Answer 95

A

Compartment syndrome
Ankle injuries

Lateral ligament injuries
Fractures of the posterior, medial and lateral malleoli
- Posterior malleolar fractures occur in:
  - 8-9% of tibial shaft fractures
  - 25-39% of distal 1/3 spiral fractures
    3. Floating knee
    4. Fracture extension into tibial plateau
Rare, but can be displaced during IM nailing
5. Knee ligamentous injury
6. Proximal tibiofibular joint dislocation

Answer 96

A

Tibia/fibula AP+lateral
Knee AP+lateral
Ankle AP, mortise+lateral

Answer 97

A

<5 degrees of varus/valgus angulation

<10 degrees of AP angulation

<10 degrees of rotation

<1cm of shortening

>50% of cortical apposition

Answer 98

A

Unacceptable alignment
Soft tissue injury not amenable to cast
Floating knee (ipsilateral femoral fracture)
Polytrauma
Morbid obesity
Unreliable patient
Vascular injury
Patient preference (favour early WB and joint ROM)

Answer 99

A

Grade I

Soft tissue injury – none or minimal
Energy – low
Typical fracture – spiral

Grade II

Soft tissue injury – superficial abrasion or contusion from fragment pressure within
Energy – mild to moderate
Typical fracture – rotational ankle fracture-dislocation
- Pressure from unreduced medial malleolus fracture

Grade III

Soft tissue injury – deep abrasion and local skin and muscle contusion from direct injury
- Also imminent compartment syndrome
Energy – high
Typical fracture – segmental tibia fracture from direct blow

Grade IV

Soft tissue injury – extensive skin contusion
- Myonecrosis
- Degloving
- Vascular injury
- Compartment syndrome
Energy – high
Typical fracture – comminution, severe

Answer 100

A

Varus

Therefore, it is a relative indication for surgery)
Also, risk for nonunion

Answer 101

A

Medial parapatellar (most common)
Lateral parapatellar
Patellar tendon split
Suprapatellar

Answer 102

A

Supine on a radiolucent table

Bump under ipsilateral hip
Radiolucent triangle

Answer 103

A

AP view
* Just medial to the lateral tibia spine
Lateral view
* Just anterior to the articular surface

Answer 104

A

True AP = lateral aspect of the lateral tibial condyle bisects the head of the fibula

Rotated AP view can change the appearance of the start point by as much as 15mm

Answer 105

A

AP view
* In line with the longitudinal axis
Lateral view
* Parallel to the anterior cortex

Answer 106

A

Level of physeal scar, centre-centre on AP and lateral views

Answer 107

A

Lock nail distally then ‘back slap’ the nail to achieve compression
Compression screw used at proximal nail in most nailing systems

Answer 108

A

Preoperative check

Ensure adequate knee ROM
Ensure canal is clear
Ensure positioning devices available
Ensure nail of appropriate size available
- Length and diameter
Ensure reduction aids available
- Large bone clamps
- Femoral distractor
- Schanz pins

Patient positioning

Supine
Radiolucent table
Bump under ipsilateral hip
Radiolucent triangle
Fluoro from opposite side

Approach
* Medial parapatellar
Identify start point with wire
Advance wire into diaphysis
Opening reamer advanced over wire
Reduce fracture and advance ball tip guidewire across fracture into distal fragment
Measure nail length
* Select nail shorter than measurement
Ream to 1.5mm larger than nail
Lock proximally through outrigger and distally with perfect circle
Confirm locking screws are through nail, fracture is reduced
Irrigate and close wounds
Full length radiographs postop to confirm alignment

Answer 109

A

47.4% (range 10-86%) at a mean followup of 24 months
Anterior knee pain is more frequently related to tibial nailing and in particular to a transtendinous approach, protrusion of the nail or a painful point of entry

Answer 110

A

Damage to intra-articular structures
* Eg. meniscus, ACL, cartilage, etc
Implant prominence
Patellar tendon and fat pad
Infrapatellar branch of the saphenous nerve
Altered biomechanics and fracture motion
Muscle deconditioning

Answer 111

A

Skin incision away from area involved in kneeling
Avoid infrapatellar branch of saphenous
* Limited incisions or horizontal incisions
Avoid protrusion of the nail (ensure countersunk)
Locking screws should be appropriate length to avoid soft tissue irritation
Avoid injury to the patellar tendon, fat pad and gliding tissues (use soft tissue protectors)
Flexion of the knee to an angle greater than 100° should give minimum contact between the introducer and the patella, making the pressure changes at the patellofemoral joint less likely

Answer 112

A

Periprosthetic fracture (TKA)
Tibia is too small for a nail
Tibia canal is not patent or deformed from prior fracture
Ipsilateral tibial plateau fracture

Answer 113

A

ATLS and resuscitation
Tetanus status
Early antibiotics
Neurovascular, compartment, soft tissue examination
Debridement

Irrigation
Remove gross debris
Cover with sterile permeable dressing

Fracture reduction and splinting

Answer 114

A

Dictated by immunization history and contamination of wound

Doses
- Tetanus toxoid-containing vaccine dose is 0.5 mL intramuscular
- Tetanus immune globulin dose is 250 units intramuscular

Answer 115

A

Type I

Clean wound <1cm in length

Type II

Clean wound >1cm in length without extensive soft tissue damage, flaps or avulsions

Type IIIA

Adequate soft tissue coverage despite extensive soft tissue damage, flaps or high energy trauma irrespective of wound size

Type IIIB

Inadequate soft tissue coverage with periosteal stripping
Often associated with massive contamination

Type IIIC

Arterial injury requiring repair

*** For prognostic reasons, severely comminuted, contaminated barnyard injuries, close range shotgun/high velocity gunshot injuries, and open fractures presenting over 24 hours from injury have all been later included in the grade III group

Answer 116

A

Type I - 0-2%

Type II - 2-10%

Type III - 10-50%

Answer 117

A

Initiate as soon as possible after injury
* Increased rate of infection in fractures managed with antibiotic prophylaxis >3 hours after injury compared with <3 hours after injury
- 7.4% versus 4.7%, respectively
Recommended 24-72 hours of antibiotic prophylaxis after initial surgical procedure

Answer 118

A

Gustilo Type I and II

1st generation cephalosporin (Cefazolin)
clindamycin or vancomycin can also be used if allergies exist

Gustilo Type III

1st generation cephalosporin (Cefazolin) + aminoglycoside (tobramycin, gentamycin)

Farm injuries, heavy contamination, or possible bowel contamination

Add high dose penicillin for anaerobic coverage (clostridium)

Special considerations [JAAOS 2005;13:243-253]

Fresh water wounds (Aeromonas hydraphila)
- Fluoroquinolones (Levofloxacin) or 3rd or 4th generation cephalosporin (eg. ceftazidime)
Saltwater wounds (Vibrio species)
- Ancef/Ceftazidime + doxycycline

Answer 119

A

Most guidelines recommend within 6 hours of injury
Gustillo type I can be delayed until the following morning
Gustillo type III, highly contaminated should be done on an urgent basis

Answer 120

A

Systematic debridement
* Start with removal of gross contamination, then layer by layer debridement
Excise all necrotic tissue

Muscle viability assessed with ‘the 4 Cs’
- Color
- Contractility
- Capacity to bleed
- Consistency

Irrigate with saline at low pressure

3 litres for Gustillo type I
6 litres for Gustillo type II and III

Limit tourniquet use

Can add ischemic insult to already compromised tissue
Limits ability to determine tissue viability

Repeat serial debridement in 48-72 hours in high energy injuries
Wound closure

Gustillo type I, II, IIIA = primary closure
- Recommend use of Donati-Allgöwer sutures to minimize the amount of cutaneous vascular compromise
Gustillo type IIIB = alternate coverage
- Consider:
  - NPWT
  - Antibiotic bead pouch in bone defect covered by semi-permeable sterile dressing
  - Masquelet technique with PMMA spacer for bone defects

Answer 121

A

Rates of reoperation were similar regardless of irrigation pressure (high, low, very low)
* Indicates that very low pressure is an acceptable, low-cost alternative for the irrigation of open fractures
The reoperation rate was higher in the soap group than in the saline group

Note: Primary end point = reoperation

Defined as surgery that occurred within 12 months after the initial procedure to treat an infection at the operative site or contiguous to it, manage a wound-healing problem, or promote bone healing

Answer 122

A

IM nail

Preferred over external fixation
- Better maintenance of length, alignment and rotation
- Less reoperation
- Better tolerated by patient and nursing

External fixation
* Used for temporary stabilization in cases of massive soft-tissue damage or as part of a damage-control protocol

Answer 123

A

As soon as patient condition allows and soft tissue coverage has been attained
* Conversion to IM should occur within 28 days
Safety interval of <10 days should be used in the management of pin-tract infections, with débridement, irrigation, and antibiotics, to allow for pin-tract granulation before IM nailing
* “Safety interval” = period of casting or bracing between removal of the external fixator and IM nailing to allow granulation of pin sites

Answer 124

A

“Vac, pack or Abx beads”

Answer 125

A

Less reoperation
Accelerated fracture healing
Less infections in Gustillo IIIA and IIIB

Answer 126

A

Proximal 1/3
* Gastrocnemius rotational flap
Middle 1/3
* Soleus rotational flap
Distal 1/3

Free flap
- Free muscle flap
  - Gracilis, rectus femoris, latissimus (small, medium, large)
  - Free muscle flaps are covered by split thickness skin grafts
- Free fasciocutaneous flap
  - Eg. Anterolateral thigh free flap
- ***NOTE – equal outcomes with free muscle and fasciocutaneous flaps

Answer 127

A

“Early flap coverage of open fractures yields the best results in terms of bony union, complication, and infection rates when compared with intermediate or late closure, as defined by our review” [J Trauma Acute Care Surg. 2012 Apr;72(4):1078-85]

Early = <72h
Intermediate = 72h-7d
Late = >7d
2. 7-10 days after injury [JAAOS 2010;18:108]

Answer 128

A

Spiral oblique pattern

Answer 129

A

Valgus deformity (most common)

Followed by recurvatum and varus

Answer 130

A

An anterior to posterior directed blocking screw in the medial one third of the distal tibia prevents medial nail positioning and subsequent valgus deformity

Answer 131

A

IM nail
* Advantages
- Minimal disruption of soft tissue envelope
- Protects extra-osseous blood supply
- Better in older patients with thin skin, diabetic patients, compromised soft tissue
- Biomechanically superior in axial loading stress
  - Compared to medial plate
    - Disadvantages
- Knee pain
- Less stable
- Increased malaligment, malunion, and nonunion
Plate

Advantages
- Direct reduction
- Improved biomechanics (twice as stiff)
- High rates of union
- Low incidence of infection, nonunion and malalignment
Disadvantages
- High risk of soft tissue complications
  - Avoid in diabetes, open fractures, hemorrhagic fracture blisters over desired incision

Minimially invasive plating

Advantages
- Biologically friendly
- Better in more distal fractures and fracture patterns prone to malalignment
Disadvantages
- Limits direct reduction
- Increased hardware prominence and irritation

Answer 132

A

Absolute indication = syndesmosis disruption
Relative indication = medial plating of the tibia to resist valgus deformation
Advantages

Improve construct stiffness
Reduce late malalignment

Disadvantages

May increase nonunion
- Decreased strain across tibia fracture

Answer 133

A

Universal distractor

Schanz pins in proximal and distal tibial physeal scar
Parallel to joint on AP
Posterior to allow for nail passage

Bent guide wire tip
Percutaneous pointed reduction forcep
Unicortical plate

Rigid plate (3.5mm compression plate)
Leave in place until locked proximally and distally

Blocking screws or wires

Large fragment screws
Interlocking screws from nail set (off label)
Steinmann pin or K-wire (2mm or greater)
Consider ‘cascading wires’ to direct path of wire and nail

Consider fixing the fibula

Answer 134

A

Add blocking screws, angle stable locking screws, more distal locking screws in multiple planes
Similar to ex-fix principles

Larger screws
More screws
Out of plane screws
Screw spread proximal distal

Answer 135

A

Anatomic reduction and stable fixation of articular surface
* Prevents nail from displacing articular surface
Then, reduction of extra-articular tibial fracture
Then, insertion of IM nail

Answer 136

A

Displaced posterior malleolar fractures can be reduced, followed by stabilization with an independent small-fragment screw(s), or an A-to-P interlocking screw through the nail
There is no evidence to support routine fixation of small, nondisplaced posterior malleolar fragments

Answer 137

A

Usually nonWB 6-8 weeks but with early ROM

WB started when evidence of callus formation is present

Answer 138

A

Valgus and procurvatum (apex anterior)

Answer 139

A

Patellar tendon
Pes anserine
Gastrocnemius
Anterior leg compartment

Answer 140

A

More lateral start point
Blocking screw lateral to midline in proximal segment
Unicortical plating
Universal distractor (Schanz pins medial tibia)

Answer 141

A

Suprapatellar start point
Semi-extended position
* Neutralizes extensor mechanism force
Start point more proximal
Blocking screw posterior in proximal segment
More proximal Herzog bend
* Stays within proximal fragment

Answer 142

A

Open reduction with unicortical plating
Percutaneous reduction forceps
Blocking screws
Percutaneous Schanz pins as joysticks
Femoral distractor applied medially with posterior positioning of the Schanz pins
More proximal and lateral start point
Suprapatellar nailing in semiextended position

Answer 143

A

Injury to patellar and femoral trochlear cartilage
Iatrogenic injury to other intra-articular structures
Joint sepsis
Intra-articular retained reaming debris
Challenge of nail removal
Possible limited nail diameter due to the size of the cannula
Need for technique-specific instrumentation

Answer 144

A

The medial tibial plateau has a concave shape and the lateral tibial plateau has a convex shape
* Helps to differentiate medial/lateral plateau on a lateral radiograph of the proximal tibia
The medial tibial plateau is larger in both length and width than the lateral tibial plateau
The lateral tibial plateau lies proximal to the medial plateau

Answer 145

A

Radiographs

AP, lateral, obliques
Tibial plateau view
- 10° caudad to parallel the tibial slope
- Generally not needed with use of CT
- Useful intraoperative view to assess reduction

CT with 3D reconstruction
* Perform post ex-fix if significant comminution present

Answer 146

A

Schatzker

Best interobserver agreement
- Agreement improves to excellent with addition of 3D reconstructions
Schatzker I – split
Schatzker II – split depressed (most common)
Schatzker III – depressed
Schatzker IV – medial condyle
Schatzker V – bicondylar
Schatzker VI – metaphyseal-diaphyseal dissociation

Answer 147

A

Articular step-off >3mm
Condylar widening >5mm
Varus/valgus instability
Medial condyle fractures
* Inherently unstable – Schatzker IV
Bicondylar fractures
* Schatzker V + VI
>5° of coronal alignment disruption [JAAOS 2018;26:386-395]

Answer 148

A

Restoration of mechanical axis alignment
* ***Most important aspect
Restoration of condylar width
Articular reduction
Restoration of knee stability

Answer 149

A

Lateral meniscus injury

Usually peripheral tears

Answer 150

A

Knee dislocation
* Femur displaces with the medial fragment
Neurovascular injury (requires ABI)
Compartment syndrome

Answer 151

A

Failure to restore mechanical axis of limb

Answer 152

A

Calcium phosphate cement

Can be injected after fixation

Answer 153

A

Schatzker VI injuries

Usually the result of:
- Severe comminution
- Unstable fixation
- Failure to bone graft
- Mechanical failure of the implant
- Infection
- Or a combination of these factors.

Answer 154

A

Inverted L incision (hockey stick) ~1cm below joint line and 1cm lateral to the anterior tibial crest with the curve over Gerdy’s tubercle
* Alternative is a lazy S extending proximally
Expose the joint capsule and the fascia overlying the tibialis anterior
Incise the fascia over the tibialis anterior and elevate the tibialis anterior off the tibial periosteum
Incise the capsule transversely then incise the coronary ligament to create a submeniscal arthrotomy

Answer 155

A

Longitudinal incision is made along the posteromedial tibial border on the medial side of the medial head of gastroc
Incise the fascia along the posterior border of pes anserinus
Place a retractor along bone of posterior tibia to retract the medial head of gastroc
* Subperiosteal elevation of popliteus may be required

Answer 156

A

Indirect reduction and percutaneous fixation

Technique:
- Leg placed on a radiolucent triangle
- Perform a tibial plateau view
- Confirm reduction with a large pointed reduction clamp
- Hold provisionally with K-wire
- Place partially threaded cannulated screws with washers
  - Minimum 2 proximal and 1 distal
- Sequentially tighten each screw

Answer 157

A

Buttress plating

Anterolateral approach
- Lazy-S, hockey stick or lateral incision centred over Gerdy’s
Submeniscal arthrotomy
Working through the fracture
- Book open with laminar spreader
Elevate the depressed joint surface
Provisional fixation with K-wire
After reduction is confirmed (visualization and fluoro), apply a 3.5mm precontoured periarticular locking plate
- Nonlocking screws distally and locking screws proximally under articular surface
  - Rafting screws
Fill bone void
Repair the meniscus

Answer 158

A

Delayed fixation

Apply spanning ex-fix with pins outside the zone of injury and zone of future plate placement
Obtain CT after application of ex-fix
Definitive fixation when soft tissues allow
- Skin wrinkling, minimal blisters
May require multiple surgical approaches
Consider staging operations
- Medial then lateral or vice versa

Answer 159

A

Average = 16% (range 1.6-40%)

Answer 160

A

Common peroneal nerve

Usually a traction palsy
- Rarely transected unless open
Peroneal palsy occurs in 25% of dislocations with 50% recovery of function
Higher incidence (44%) in ultra-low energy mechanisms
- Typically obese patients

Answer 161

A

Based on the direction of the tibia displacement relative to femur (Kennedy classification)

Anterior
- Most common direction
- Caused be hyperextension mechanism
  - Sequential failure of posterior capsule, PCL and sometimes ACL
- Popliteal artery injury usually an intimal tear due to traction
Posterior
- Second most common
- Caused by posteriorly directed force to proximal tibia
- Popliteal artery injury usually a transection
Medial
Lateral
Rotatory
- PCL remains intact as tibia rotates about the femur
  1. Schenk classification
Based on severity/pattern of ligamentous damage
KD I (1 crucuate)
- ACL or PCL injured
- +/- collaterals
KD II (2 ligs)
- ACL and PCL injured
KD III (3 ligs)
- ACL, PCL
- Medial OR lateral collateral
KD IV (4 ligs)
- ACL, PCL, MCL, LCL
KD V
- Fracture dislocation

NOTE: For KD III injury, the injury is written as KD IIIM or KD IIIL, depending on whether the medial or lateral collateral ligament is damaged.

The subdesignations C and N indicate the presence of vascular and neural injury, respectively

Answer 162

A

Prereduction AP and lateral knee xray
Postreduction AP and lateral knee xray
CT scan if periarticular or intraarticular fracture identified on xray
MRI obtained after successful reduction

Answer 163

A

Conscious sedation
Reverse the deformity
Once reduced splint the knee in 20° flexion,
* Plaster splint preferred
Postreduction xray to confirm reduction

Answer 164

A

Occurs when the medial femoral condyle buttonholes through the medial capsule and entraps the MCL drawing it into the joint

Often represents an irreducible dislocation

Answer 165

A

Pre- and post reduction assess for ‘hard signs’ of vascular injury and palpate pulses (DP and PT)

Hard signs:
- Cold
- Pale
- Delayed capillary refill
- Pulsatile hematoma
- Absent pulse

If pulses are absent or hard signs present, vascular surgery consult (no ABI) for emergent vascular exploration
If pulse is present assess symmetry of pulse and ABI

If asymmetrical pulse or ABI <0.9 = CT angiogram (CTA)
If pulses symmetric and ABI >0.9 = admit for 24h observation with serial examination and ABIs

Answer 166

A

Open dislocation
vascular repair
Reduction not maintained in splint

Answer 167

A

The preferred treatment of knee dislocations under ideal circumstances consists of:

Arthroscopic ACL and PCL reconstruction
Open LCL/PLC and/or MCL/PMC reconstruction

Answer 168

A

PCL → ACL → PLC → PMC

PCL is reconstructed first to restore native anatomic tibiofemoral relationship and to prevent posterior displacement of the tibia with ACL tensioning

Answer 169

A

Reconstruct ACL, PCL, and PLC
Repair or reconstruct PMC

Answer 170

A

PCL

Achilles tendon allograft for single bundle
Achilles tendon allograft (anterolateral) and tibialis anterior allograft (posteromedial) for double bundle

ACL
* Achilles tendon or other allograft
PLC
* Achilles allograft
PMC
* Allograft - two semitendinosis grafts or one anterior tibialis graft

Answer 171

A

In general for ACL/PCL + PLC or PMC injuries:
* If capsule is disrupted precluding arthroscopy first repair/reconstruct the PLC or PMC in the first week then do arthroscopic reconstruction of the ACL/PCL at 3-6 weeks
For ACL, PCL and PLC injuries timing is dependent on:

Fanelli and Feldmann classification:
- Type A = increase in external rotation only
  - Injury to the popliteofibular ligament and popliteus tendon
- Type B = increase in external rotation and increased varus laxity of approximately 5 mm at 30° of flexion
  - Injury to the popliteofibular ligament, popliteus tendon, and LCL
- Type C = increase in external rotation and gross varus laxity of approximately 10 mm at 30° of flexion
  - Injury to the popliteofibular ligament, popliteus tendon, LCL, and lateral capsule
Type A and B
- Single stage arthroscopic ACL/PCL recon with open lateral side recon in first 2-3 weeks
Type C
- Staged open lateral side recon in first week with arthroscopic ACL/PCL recon at 3-6 weeks

For ACL, PCL and PMC injuries timing is dependent on:

Fanelli and Harris classification
- Type A = axial rotation instability (either anteromedial or posteromedial) with no valgus instability
- Type B = axial rotation instability and valgus laxity at 30° of flexion with a firm end point
- Type C = axial rotation instability and valgus laxity at 30° of flexion with no end point
Type A and B
- Single stage arthroscopic ACL/PCL recon with open medial side repair/recon in first 2-3 weeks
Type C
- Staged open medial side repair/recon in first week with arthroscopic ACL/PCL recon at 3-6 weeks