Femoral neck fractures

Borrowed heavily from OTA core curriculumAuthors: Steven A. Olson, MD and Brian Boyer, MD

Kenneth J Koval, MD

Anatomy

• Physeal closure age 16• Neck-shaft angle

130° ± 7°• Anteversion

10° ± 7°• Calcar femorale

Posteromedial

dense plate of bone

Blood supply

• Lateral epiphysel artery– terminal branch MFC artery– predominant blood supply to

weight bearing dome of head

• Artery of ligamentum teres– from obturator artery– supplies anteroinferior head

• Lateral femoral circumflex a.– less contribution than MFC

Epidemiology

• 250,000 Hip fractures annually– Expected to double by 2050

– 50% are femoral neck fractures

• At risk populations– Elderly: poor balance & vision, osteoporosis, inactivity,

medications, malnutrition• incidence doubles with each decade beyond age 50

– Young: high energy trauma

Classification

• Pauwels [1935]

– Angle describes vertical shear vector

Classification

• Garden [1961]

I Valgus impacted or

incomplete

II Complete

Non-displaced

III Complete

Partial displacement

IV Complete

Full displacement

** Portends risk of AVN and Nonunion

I II

III IV

Classification

• Functional Classification – Stable

• Impacted (Garden I)

• Non-displaced (Garden II)

– Unstable• Displaced (Garden III and IV)

Treatment

• Options– Non-operative

• very limited role

– Operative• ORIF

• Hemiarthroplasty

• Total hip replacement

Non-displaced fractures

• ORIF standard of care• Predictable healing

– Nonunion < 5%

• Minimal complications– AVN < 8%

– Infection < 5%

• Relatively quick procedure– Minimal blood loss

• Early mobilization– Unrestricted weight bearing with assistive device PRN

Displaced fractures

ORIF versus replacement

Most important considerations

are life expectancy and activity level

Young adults

• Closed or open reduction and internal fixation is the procedure of choice

• Emergent surgery

ORIF: most important variable is quality of reduction

Approach for open reduction

Smith-Peterson• Anterior approach

• Best for transcervical and subcapital fractures

• Fixation is performed through a second approach

Approach for open reduction

Watson-Jones• Anteriolateral exposure

• Best for basalar neck and IT patterns

• Allows placement of implant through same incision

What reduction is acceptable?

• Ideal reduction is Anatomic– Acceptable: < 15º valgus < 10º AP angulation

• Any varus is unacceptable

Screw fixation

• Screw location– Avoid posterior/ superior quadrant

» Blood supply

» Cut-out

– Biomechanical advantage to inferior/ calcar screw

Sliding hip screw fixation

• Compression Hip Screws– Sacrifices large amount of bone

– May injure blood supply

– Biomechanically superior in cadavers

– Anti-rotation screw often needed

– Increased cost and operative time

• No clinical advantage over parallel screws * May have role in high energy/ vertical shear

fractures

Sedentary elderly

•Arthroplasty is the procedure of choice, usually a hemiarthroplasty

Unipolar vs. bipolar

• Bipolar theoretical advantages• Lower dislocation rate• Less acetabular wear/ protrusio• Less pain

Cochrane collaboration 2010

• Hemiarthroplasty–From the trials to date there is no

evidence of any difference in outcome between bipolar and unipolar prostheses

Cemented versus uncemented

• ? 1% sudden death• less pain• better function

Active elderly

•Treatment of choice for displaced femoral neck fractures is controversial

ORIF vs (hemi) arthroplasty for displaced femoral neck fractures

• ORIF - reduced operative time, operative blood loss, need for transfusion, and risk of deep wound infection

• Arthroplasty - lower revision rate• No differences found in hospital LOS,

mortality, residual pain, or regaining mobility

Cochrane review 2002

Recent re-evaluation for role of THR for treatment

of acute femoral neck fractures in the active

elderly

ORIF vs Bipolar vs THR

• Prospective randomized multicenter• Displaced FN fxs, pts > 60 years• 298 pts- ORIF (118); cemented bipolar (111);

cemented THR (69)• ORIF fixation failure (AVN,NU) - 37%• ORIF – 8x more likely to require revision surgery

than bipolar and 5x than THR• Functional outcome highest for THR

Keating et al, JBJS 2006

Treatment for displaced Femoral neck fractures

• Younger individuals: ORIF• Oldest old: Hemiarthroplasty• Middle range of the elderly: Controversial

– Hemiarthroplasty (unipolar) for displaced femoral neck fractures in sedentary elderly 65-80 years old

– THR for active individuals and those with pre-existing acetabular disease

– ORIF for active elderly with understanding that there is a high risk for revision surgery

Thank you