11/18/2015

1

Femoral Neck Fractures :

My Thoughts

Dean G. Lorich, MD

New York, NY

No disclosures

Inverted Triangle?

This is what frequent does

happens…

11/18/2015

2

Valgus impacted = stable

•21 % reop

•49% reop - tilt

>20

•10% - <10 deg

Goal:

•Minimize complication of interupted vascularity of femoral head

•Heal femoral neck

•Maintain hip anatomy x

A malunion is not the endpoint of

success

11/18/2015

3

Intracapular femoral neck

fracture :

•Reoperation :• IF - 20-36%

•AVN - 30%

•Nonunion – 16%

• Arthroplasty

•THA – 5-7%

•Bipolar – 6-7%

Tidermark etal JOT 02

X

FEMORAL NECK FRACTURES:

• WHY CAN’T WE RELIABLY

HEAL THE FRACTURES

AND

IN AN ACCEPTABLE POSITION?

How do neck fractures heal

•Beneath the synovial membrane,

periosteum covers proximal femur•Periosteum lacks a cambium layer on

the femoral neck, accounting for the

lack of callus formation of fracture

11/18/2015

4

Femoral head vascularity:

Gautier, Ganz 00

Gad-MRI : comparison

11/18/2015

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Gad MRI: Quantitate

contribution of the

inferior vincular artery

Femoral neck fracture:

vascularity

•Observation•Vascularity is not as tenuous as we were

lead to believe

•2 main terminal branches of MFCA

•Posterosuperior – usually injury

•Posteroinferior – always intact

Is sliding necessary for healing?

Is AVN an inevitability of poor

reductions and unstable

fixation?

11/18/2015

6

“ Most treatments work because of the

relative indestructibility of the human

musculoskeletal system.”

Henry Mankin, MD

•Minimize complication of interupted vascularity of femoral head

•Heal femoral neck

•Maintain hip anatomy

Can we????

REDUCTION is critical

11/18/2015

7

Without it … failure is

predictable

Strict adherence to reduction of

ALL fractures (including valgus

“impacted”)

11/18/2015

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Younger =

OPEN Reduction

Open reduction

1 year

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Results:• Average Age was 78 years

• Classification• 2 nondisplaced

• 15 Garden I - reduced

• 16 Garden III,

• 21 Garden IV patients.

• 54/57 (95%) patients healed successfully.• of the 54

• No complications

• No revision surgery needed).

• Of the 3 failures

• AVN - 1.

• 2 non-union requiring arthroplasty.

J Trauma 2010

Radiographic analysis:

•Average head migration

was 1.98 mm

J Trauma 2010

Gait analysis results: Contd.• Average return of SLS (single

limb stance) of involved limb

when compared to normal

side was:• 79% at 6 weeks

• 86% at 3 months

• 93% at 6 and 12 months.

• No improvement between 6

and 12 months.

70%

75%

80%

85%

90%

95%

6 weeks

3 Month

s

6 month

s

12 month

s

S L S

C olumn1C olumn2

AOTS 2011

11/18/2015

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Intracapular femoral neck

fracture :

•Function status : able to walk w/ or

w/o cane• Internal fixation – 63 (44-97)

•Bipolar – 85 (64-93)

•THA - 87 (76- 90)

Tidermark etal JOT 02

Build a better mouse trap?

Results : locking femoral neck

plate

•21 consecutive femoral neck

fractures• 18 w f/u >16mos

• 17/18 w anatomic reduction

JOT 2012

11/18/2015

11

16 weeks12 weeks

6 weeks

Results : locking femoral neck

plate•11/18 – achieved union comparable

radiographic results in our original study

•7/18 – catastrophic failure• Screw breakage• Intraarticular screw penetration• Plate pull off from shaft

•5 - THA

JOT 2012

Why : do we need some

dynamization in hip fractures?implant-bone relationship weakens over time

– loosening / instability over time

11/18/2015

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57 yo – 48 hrs p injury

Ideally : implant /bone interface

strengthens over time

6 mos

Allograft

incorporation

11/18/2015

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Endosteal Biologic Augmentation for Surgical Fixation of Displaced Femoral Neck Fractures

JOT 2015

• Patients and Methods: 27 patients with isolated

displaced FNF surgically treated by a single

surgeon.

• Intervention: Open reduction of the femoral neck,

fixed with a length- and angle stable-construct of

two fully threated cannulated screws augmented

with an endosteal fibular allograft serving as a

biologic dowel.

Endosteal Biologic Augmentation for Surgical Fixation of Displaced Femoral Neck Fractures

JOT 2015

• Main Outcome Measurements:

–Clinical and radiographic outcomes

of the fixation construct

–Viability of both the femoral head and

the fibular allograft

Endosteal Biologic Augmentation for Surgical Fixation of Displaced Femoral Neck Fractures

JOT 2015

- MRI 12 months postop

- partial or complete osseous

incorporation of the fibular allograft

in 86% of the patients

11/18/2015

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Endosteal Biologic Augmentation for Surgical Fixation of Displaced Femoral Neck Fractures

JOT 2015

- HHS - excellent outcomes (91 ±13.2).

- SF-36

- Mental - 52.9 ±11.8

- Physical 50.5 ±8.3.

- All patients demonstrated

- normal gait without need for assistive devices

- Gait analysis

- 98% of single-limb stance time

- 100% of cadence,

- 96% of cycle duration

- 98% in stride length compared with uninjured side.

Natural History of Post-Traumatic Osteonecrosis of the Femoral Head Following Stable Anatomic Fixation of Displaced

Femoral Neck Fractures

• Results- Pre-op DCE MRI

• injured side VS the contralateral side.

• decreased perfusion (73.8%) - arterial

• increased washout delay (199%) - venous

• some perfusion to the femoral head was always

noted in the injured side.

Natural History of Post-Traumatic Osteonecrosis of the Femoral Head Following Stable Anatomic Fixation of Displaced Femoral Neck Fractures

• Results- Post op MAVRIC MRI

– MRI revealed AVN segments in 87% (20/23)

of patients.

– All AVN segments developed in the anterior

aspect of superomedial quadrants

– area of higher decrease perfusion on

pre-op DCE MRI)

11/18/2015

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Natural History of Post-Traumatic Osteonecrosis of the Femoral Head Following Stable Anatomic Fixation of Displaced

Femoral Neck Fractures

• Results- Post op MAVRIC MRI

– The ON segment involves a small percentage of

the femoral head

– 14% at 3months

– 13% at 12 months

– 1yr MRI - 17% (4/23) had minimal subchondral

collapse (<2mm)

–2YR xray - 0/23 – demonstrated any

segmental collapse

Natural History of Post-Traumatic Osteonecrosis of the Femoral Head Following Stable Anatomic Fixation of Displaced Femoral Neck Fractures

• Extend of the ON segment

– Proportion of the cross-sectional area of the head-

Collapse rate (Nam et al JBJS 2008)

– 5% in small lesions (<30%)

– 46% in medium lesions (30%-50%)

– 83% in large lesions (>50%)

– All except one of the ON segments in our cohort were

small lesions (range 3.0-24.6%; one with medium

lesion -31.8%)

– > 2/3 of the weight-bearing area of the Femoral

head present a significant higher rate of collapse (Nishii CORR 2002)

- All our patients with ON occupy < 2/3 of the weight

bearing area

If anatomy cannot be restored

and maintained - THA

•My learning curve•No respect for the amount of

displacement or timing of injury

•Reduction on the OR table is critical

•Critical evaluation is:

• “Can a stable construct of the calcar be accomplished?”

• “is it worth trying to saving the hip in this particular patient?”

11/18/2015

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Calcar reduction possible?

•Compression at the time of surgery

•Construct should allow post op compression without excess sliding capability

•Fixed angle to maintain alignment

Convinced

•Can heal displaced femoral fractures•Reliably

•Near anatomically

•Without significant clinical risk related to AVN