Subtrochanteric Femoral

Fractures
Brandon J. Yuan, MD
Assistant Professor of Orthopedic Surgery
Mayo Clinic, Rochester, MN

Core Curriculum V5
Disclosures
• Images: all figures and images property of Brandon Yuan, MD unless
otherwise indicated

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Objectives
• Anatomy
• Define unique anatomical considerations of subtrochanteric femur fractures
• Technique
• Describe the important considerations of positioning, starting point, and
nail design when treating a subtrochanteric fracture with a medullary nail
• Controversy
• Recognize which subtrochanteric fractures are not appropriately treated
with a medullary nail, and describe alternative methods of treatment
• Clinical application
• Identify the important characteristics of an atypical subtrochanteric fracture
and their implications for management

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Introduction
Subtrochanteric Femur Fractures

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Bimodal Incidence and Mechanism

Young patients “Geriatric” patients

• High energy • Low energy – Fall from
• Associated limb/life standing
threatening injuries • Beware of the Aytpical
common subtrochanteric femur
fracture

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Bimodal Incidence and Mechanism
• Young – High energy
• Think about…
• ATLS protocols
• Associated injuries
• Temporary stabilization
• Traction

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Bimodal Incidence and Mechanism
• Older - Low energy
• Think about…
• Prodromal pain?
• History of other fragility
fractures
• Medications?
• Contralateral stress
fracture?
• Endocrine evaluation at
follow up

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Anatomy
Subtrochanteric Femur Fractures

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Anatomy – Proximal femur
• Must understand bony
and soft tissue anatomy
• Critical implications for
surgical treatment

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Bony Anatomy – Proximal femur
• Region of maximal
compressive forces
(medially) and tensile forces
(laterally)
• Largest asymmetric
difference in load in
single long bone in the
body

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-2. Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
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Bony Anatomy – Proximal femur
• Region of maximal • Clinical application 
compressive forces • Bone heals under
(medially) and tensile compression but lateral
forces (laterally) cortex is always under
• Largest asymmetric tension!
difference in load in • Reduction  no lateral
single long bone in the cortical gapping (no
body varus)
• Fixation  must allow
for compression of
lateral cortex

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Bony Anatomy – Proximal femur
• Fracture isolates short
proximal fragment

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Bony Anatomy – Proximal femur
• Fracture isolates short
proximal fragment • Clinical application 
• Presents similar
challenges to proximal
tibia, proximal
humerus fractures
• Segment is short and
thus room for error
becomes very small
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Soft Tissue Anatomy – Proximal femur
• Multiple large muscles
act on proximal segment
• External rotation
• Iliopsoas and short
external rotators

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-4. Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
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Soft Tissue Anatomy – Proximal femur
• Multiple large muscles
act on proximal segment
• Flexion
• Iliopsoas and
abductors

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-4. Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
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Soft Tissue Anatomy – Proximal femur
• Multiple large muscles act
on proximal segment
• Abduction (or varus)
• Abductors

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-4. Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
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Soft Tissue Anatomy – Proximal femur
• And distal segment!
• Adductors 
Shortening and medial
translation

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-4. Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
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 Soft Tissue Anatomy – Proximal femur
• Multiple large muscles act • Clinical application 
on proximal (and distal) • Must overcome all forces
segment to obtain reduction

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-4 and 54-9. Rockwood and Green’s Fractures in Adults, editors
Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
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Classification
• Fractures within 5 cm of
the lower extent of the
lesser trochanter

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Classification
• Fractures within 5 cm of
the lower extent of the
lesser trochanter
• OTA classification
• Both ”31” and “32”
sections

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,

Figure 54-3. Rockwood and Green’s Fractures in Adults, 9th edition. Editors
Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
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Technique
Surgical fixation of Subtrochanteric Femur Fractures

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Technique – Antegrade intramedullary nail
• Majority of cases 
Antegrade, locked
intramedullary nail
• Exceptions covered in
“Controversy”
segment

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Technique – Antegrade intramedullary nail
• Majority of cases  Antegrade,
locked intramedullary nail
• Biomechanical and clinical data
– Nail vs plates:
• Nails:
• Greater load to failure
• Greater number of cycles
to failure
• Higher force at failure
Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter
Kuzyk, P et al. Intramedullary Versus Extramedullary Fixation for Subtrochanteric Femur
Fractures. J Orthop Trauma. 2009;23(6):465-470 Core Curriculum V5
54, Figure 54-3. Rockwood and Green’s Fractures in Adults, 9th edition.
Editors Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
Positioning
• Supine – Free leg
• Skeletal traction over end of bed
• Advantages
• Free control and access to limb
by surgeon
• Ability to maximally adduct limb
for access to starting point
• Supine positioning for
polytrauma patient
• Disadvantages
• Potential need for additional
scrubbed assistant
• More challenging access for
open reduction

Image: Adams JD and Jeray KJ, Femoral Shaft Fractures, Chapter 56,
Figure 56-13. Rockwood and Green’s Fractures in Adults, 9th edition.
Editors Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
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Positioning
• Supine – Traction table
• Advantages
• Ability to hold
reduction/traction without
need for assistant
• Supine positioning for
polytrauma patient
• Disadvantages
• Traction table complications –
nerve palsy, skin injury
• More challenging access for
open reduction
• Sustained traction can
accentuate proximal fragment
deformity
Image: Adams JD and Jeray KJ, Femoral Shaft Fractures, Chapter 56,
Figure 56-14. Rockwood and Green’s Fractures in Adults, 9th edition.
Editors Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
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 • OTA Video Link:
• Intramedullary Nailing in the Lateral Position without a Traction Table for
an Atypical Subtrochanteric Femoral Fracture

Positioning
• Lateral – Free leg
• Advantages
• Overcomes abduction of proximal
fragment
• Ability to move distal segment in
sagittal plane to match flexion of
proximal fragment
• Improved access for open reduction
and to starting point in obese
patients
• Disadvantages
• Obtaining imaging of proximal femur
can be unfamiliar or difficult
• Contralateral leg less accessible for
rotational comparison

Image: OTA PowerPoint, Femoral shaft fracture, revision 11/2009. Slide 41

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Reduction
• Medullary nail technique is
optimally paired with closed,
functional reduction to maximally
preserve fracture biology

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Reduction
• Medullary nail technique is optimally
paired with closed, functional reduction to
maximally preserve fracture biology
• But…
• Subtrochanteric femur is not tolerant to
malreduction, particularly varus and
flexion!
• Thus have a low threshold to perform open
reduction to ensure:
• No Varus
• Acceptable sagittal plane and rotational
reduction

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Reduction
Well-aligned fracture via open
reduction is always preferable to… The percutaneous malreduction

> Image: Yoon RS and Haidukewych

GJ, Subtrochanteric Fractures,
Chapter 54, Figure 54-19.
Rockwood and Green’s Fractures
in Adults, 9th edition. Editors
Tornetta, Paul; Ricci, William.
Wolters Kluwer, 2019

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Reduction
• Closed reduction
• Traction
• F-tool
• Intramedullary
reduction aid

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Reduction
• Open reduction
• Picador/cobb
elevator/bone
hook/Shanz pins

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Reduction
• Open reduction
• Picador/cobb
elevator/Shanz pins

• Reduction
clamp/colinear clamp

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 Reduction
• Open reduction
• Picador/cobb
elevator/Shanz pins

• Clamp/bone
hook/colinear clamp

• Cerclage cable/plate
assisted reduction
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Intramedullary nailing
• Several critical technical
points
• Starting point
• Nail design
• Proximal locking

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Intramedullary nailing – Starting point
• Error:
• Too anterior and too
lateral
• If using trochanteric start
nail:
• Start medial to the tip of
the greater trochanter
• Will encourage valgus

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 Intramedullary nailing – Starting point
• Error:
• Too anterior and too lateral
• If using trochanteric start nail:
• Start central or even
posterior on the greater
trochanter
• Will fight against flexion
of proximal fragment
Yoon RS et al., Reducing Subtrochanteric Femur Fractures: Tips and Tricks, Do's
and Don’ts. J Orthop Trauma, 2015:29,S28-S33. Figure 2
Core Curriculum V5
 Yoon RS et al., Reducing Subtrochanteric Femur Fractures: Tips and Tricks, Do's
and Don’ts. J Orthop Trauma, 2015:29,S28-S33. Figure 2

Intramedullary nailing – Starting point

• This relatively anterior starting point…

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 Yoon RS et al., Reducing Subtrochanteric Femur Fractures: Tips and Tricks, Do's
and Don’ts. J Orthop Trauma, 2015:29,S28-S33. Figure 2

Intramedullary nailing – Starting point

• This relatively anterior starting point…
• Will lead to this entry reamer path…

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 Yoon RS et al., Reducing Subtrochanteric Femur Fractures: Tips and Tricks, Do's
and Don’ts. J Orthop Trauma, 2015:29,S28-S33. Figure 2

Intramedullary nailing – Starting point

• This relatively anterior starting point…
• Will lead to this entry reamer path…
• And this final reduction in flexion!

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Intramedullary nailing – Starting point
• Error:
• Too anterior and too
lateral
• Use piriformis nail
• Starting point in line with
intramedullary pathway
in distal segment
• Starting point is already
medial and posterior

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Intramedullary nailing – Starting point

Piriformis starting point Trochanteric starting point

• Advantages • Advantages
• In line with anatomic location • Easier access in larger patients
of femoral shaft • Less risk of malrotation
• Starting point is medial and • Avoid piriformis fossa if
posterior fracture extends there
• Disadvantages • Disadvantages
• Higher risk of malrotation • Watch out for too anterior
• Piriformis comminution starting point  mal-
prevents optimal proximal reduction in flexion
fragment stability

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Intramedullary nailing – Reaming
• Error:
• Proximal reaming
directed too medially
distally  will lead to
varus

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Intramedullary nailing – Reaming
• Error:
• Proximal reaming
directed too medially
distally
• Natural tendency of
starting pin to go from
lateral proximal to distal
medial due to body
habitus of patient
• Often accentuated by
medial comminution

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Intramedullary nailing – Reaming
• Error:
• Proximal reaming directed too
medially distally
• Fix
• Ensure proper path of starting
guidewire on both views
• Don’t ream the proximal
fragment while flexed and
abducted
• Use Cobb/clamp/Shanz pin to
reduce deformity prior to
reaming

Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter

Core Curriculum V5
54, Figure 54-13. Rockwood and Green’s Fractures in Adults, 9th edition.
Editors Tornetta, Paul; Ricci, William. Wolters Kluwer, 2019
Intramedullary nailing – Proximal locking
• Potential error:
• Failure to lock into the femoral head in geriatric
patients
• Fix:
• Consider nail with option to lock into the femoral
head in geriatric patients with low energy patterns

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Intramedullary nailing – Nail Design

“Reconstruction” style nail

• Smaller proximal body
• Different proximal locking
options
• Two interlocking screws
into head
• Antegrade interlocking
bolts
• Transverse interlocking
bolts

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Intramedullary nailing – Nail Design

“Hip Fracture” style nail

• AKA “cephalomedullary
nail”
• Large proximal body
• Typically one large lag
screw/blade  Femoral
head
• Variations with smaller
secondary screw
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Intramedullary nailing – Nail Design

• No data showing superiority of one type of nail over the

other for subtrochanteric fractures of the femur
• However…A reconstruction style nail will remove less overall
bone from the proximal femur, which may be beneficial in
the young patient, particularly if nail removal is later
performed

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Controversy

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When a nail might not work
• Comminution of the nail
starting point
• Tip of greater
trochanter or
piriformis fossa

Berkes MB et al., Ninety-Five Degree Angled Blade Plate Fixation of High-Energy

Unstable Proximal Femur Fractures Results in High Rates of Union and Minimal
Complications. J Orthop Trauma, 2019:33(7),335-340. Figure 1 Core Curriculum V5
When a nail might not work
• Solution:
• A plate is still a viable
option
• 95 degree blade plate

• OTA Video link:

• Use of the 95 Degree
Angled Blade Plate to
Treat a High Energy
Proximal Femur Fracture
Berkes MB et al., Ninety-Five Degree Angled Blade Plate Fixation of High-Energy
Unstable Proximal Femur Fractures Results in High Rates of Union and Minimal
Complications. J Orthop Trauma, 2019:33(7),335-340. Figure 4
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When a nail might not work
• Solution:
• A plate is still a viable
option
• Proximal femoral
locking plate

Medda S et al., Treatment of Peritrochanteric Femur Fractures With Proximal

Femur Locked Plating. J Orthop Trauma, 2019:33(7),341-345. Figure 3
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When a nail might not work
• Revision fixation with
poor starting point
• Mal-reduction in
varus/flexion with
poor starting point and
prior nail in place can
be next to impossible
to correct with nail
alone

Figure belongs to Brandon Yuan, MD Core Curriculum V5

When a nail might not work
• Revision fixation with
poor starting point
• Note very lateral
starting point/nail path
• Correcting varus with
another nail in the
short proximal
segment is very
difficult
Figure belongs to Brandon Yuan, MD Core Curriculum V5
When a nail might not work
• Revision fixation with
poor starting point
• Bone grafting old start
point/lag screw path
• Blade plate 
correction of varus

Figure belongs to Brandon Yuan, MD Core Curriculum V5

Clinical Application

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Atypical Femoral fractures
• Atraumatic/low-energy
femoral fractures of the
subtrochenteric region or
femoral shaft
• Atypical Femur fracture =
AFF

Image: Bogdan Y, Atypical Femur Fractures, Chapter 55, Figure 55-1.

Core Curriculum V5
Rockwood and Green’s Fractures in Adults, editors Tornetta, Paul;
Ricci, William. Wolters Kluwer, 2019
 Atypical Femur Fractures
• Pathogenesis
• Likely stress fracture occurring
in abnormal underlying bone
• Remodeling suppression –
Occurs with use of
bisphosphonates
• Puts femur at risk for
decreased healing of small
stress fractures  larger
stress reactions  Clinically
relevant AFF

Black JD et al., A Review of Atypical Femoral Fractures From a Tertiary Care

Teaching Hospital: An Alarming Trend?. J Orthop Trauma. 2016;30(4):182-188.
Figure 3-A
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• Outlined Case definition for AFFs – Revised in 2013
• “Fracture must be located along the femoral diaphysis from just distal
to the lesser trochanter to just proximal to the supracondylar flare”
• “In addition, at least four of five Major Features must be present.”
• “None of the Minor Features is required but have sometimes been
associated with these fractures.”

Shane E et al., Atypical Subtrochanteric and Diaphyseal Femoral Fractures:

Second Report of a Task Force of the American Society for Bone and Mineral
Research. J. Bone Miner. Res; 2014, 29:1–23
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• Major features (need 4 or 5)
1. The fracture is associated
with minimal or no
trauma
2. The fracture line
originates at the lateral
cortex and is transverse

Shane E et al., Atypical Subtrochanteric and Diaphyseal Femoral Fractures: Image: Cho JW et al. Healing of Atypical Subtrochanteric Femur Fractures After
Second Report of a Task Force of the American Society for Bone and Mineral
Research. J. Bone Miner. Res; 2014, 29:1–23
Cephalomedullary Nailing: Which Factors Predict Union?. J Orthop Trauma.
2017;31(3):138-145. Figure 1 C ore Curriculum V5
• Major features (need 4 or 5)
3. Medial spike
4. No or minimal
comminution
5. Localized periosteal or
endosteal thickening of the
lateral cortex is present at the
fracture site (“beaking” or
“flaring”)
Shane E et al., Atypical Subtrochanteric and Diaphyseal Femoral Fractures: Image: Cho JW et al. Healing of Atypical Subtrochanteric Femur Fractures After
Second Report of a Task Force of the American Society for Bone and Mineral
Research. J. Bone Miner. Res; 2014, 29:1–23
Cephalomedullary Nailing: Which Factors Predict Union?. J Orthop Trauma.
2017;31(3):138-145. Figure 1 C ore Curriculum V5
• Minor features
• Increased cortical
thickness of diaphysis
• Prodromal symptoms
such as dull or aching
pain in the groin or thigh
• Bilateral incomplete or
complete femoral
diaphysis fractures
• Delayed fracture healing

Shane E et al., Atypical Subtrochanteric and Diaphyseal Femoral Fractures:

Second Report of a Task Force of the American Society for Bone and Mineral
Research. J. Bone Miner. Res; 2014, 29:1–23 Core Curriculum V5
Atypical Femoral fractures – BEWARE!
• Nature of the AFF leads
to lower healing rates,
and abnormal lateral
cortex.
• AFF are intolerant to
varus!
• As little as 5 degrees
 Failure!
• Cho et al, JOT 2017
Image: Rollick N et al. Orthogonal Plating With a 95-Degree Blade Plate
for Salvage of Unsuccessful Cephalomedullary Nailing of Atypical Femur
Fractures: A Technical Trick. J Orthop Trauma. 2019;33(6):e246-e250.
Figure 1
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Atypical Femoral fractures – BEWARE!
• AFF are associated with
abnormal femoral
geometry
• Varus and anterior
bowing
• Beware of anterior nail
perforation distal!

Shane E et al., Atypical Subtrochanteric and Diaphyseal Femoral Fractures: Image: Collinge CA and Beltran MJ. Does Modern Nail Geometry Affect Positioning
in the Distal Femur of Elderly Patients With Hip Fractures? A Comparison of
Second Report of a Task Force of the American Society for Bone and Mineral
Research. J. Bone Miner. Res; 2014, 29:1–23 Otherwise Identical Intramedullary Nails With a 200 C
Versus 150 cm Radius of Curvature. J Orthop Trauma. 2013;27:299-302. Figure 2
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Atypical Femoral fractures – BEWARE!
• Look for contralateral fractures
• 28-53% of cases

Capeci CM et al. Bilateral low-energy simultaneous or sequential femoral

Image: Black JD et al., A Review of Atypical Femoral Fractures From a Tertiary
Core Curriculum V5
fractures in patients on long-term alendronate therapy. J Bone Joint Surg Am
2009; 91: 2556-61. Care Teaching Hospital: An Alarming Trend?. J Orthop Trauma. 2016;30(4):182-
188. Figure 3B
Atypical Femoral fractures – BEWARE!
• Anticipate prolonged healing
time
• 5- 10 months!
• Bogdan Y. et al., JOT 2016; 30:177-
181
• Medical treatment
• Stop bisphosphonates
• Ca and Vit D supplementation
• Consider anabolic agents (ex:
teraperatide, etc)

Bogdan Y et al., Healing Time and Complications in Operatively Treated Atypical

Image: Black JD et al., A Review of Atypical Femoral Fractures From a Tertiary
Core Curriculum V5
Femur Fractures Associated With Bisphosphonate Use: A Multicenter
Retrospective Cohort. J Orthop Trauma. 2016 Apr;30(4):177-81. Care Teaching Hospital: An Alarming Trend?. J Orthop Trauma. 2016;30(4):182-
188. Figure 3B
 Image: Yoon RS and Haidukewych GJ, Subtrochanteric Fractures, Chapter 54,
Figure 54-2 and 4. Rockwood and Green’s Fractures in Adults, editors Tornetta,
Paul; Ricci, William. Wolters Kluwer, 2019

Summary
• Anatomy
• The unique muscular and mechanical forces through the subtrochanteric
region have significant implications for fracture reduction and fixation

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Summary
• Technique
• Positioning lateral or supine
• Starting point medial to tip of greater trochanter or piriformis
fossa
• Consider options to lock across the femoral neck in
geriatric/osteoporotic patients

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 Summary
• Controversy
• Comminution of the starting point of the nail (greater trochanter
or piriformis fossa) is a relative indication for use of a plate
• Very lateralized or anterior starting points can be difficult to
correct at the time of revision surgery, and may require revision
to a plate

Berkes MB et al., Ninety-Five Degree

Angled Blade Plate Fixation of High-
Energy Unstable Proximal Femur
Fractures Results in High Rates of
Union and Minimal Complications. J
Orthop Trauma, 2019:33(7),335-340.
Figure 1 Figure belongs to Brandon Yuan, MD

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 Summary
• Clinical application
• AFF have specific defining characteristics
• Lateral beaking
• Transverse/minimally comminuted fracture line
• Medial beaking
• Low energy/no trauma

Image: Cho JW et al. Healing of Atypical Subtrochanteric Femur

Fractures After Cephalomedullary Nailing: Which Factors Predict
Union?. J Orthop Trauma. 2017;31(3):138-145. Figure 1
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Summary
• AFF
• Beware!
• Intolerant to malreduction
• Abnormal femoral geometry
• Contralateral fractures common
• Prolonged healing time

Image: Cho JW et al. Healing of Atypical Subtrochanteric Femur

Fractures After Cephalomedullary Nailing: Which Factors Predict
Union?. J Orthop Trauma. 2017;31(3):138-145. Figure 1
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