acetabula fractures

Acetabular Fractures

Joshua Landau, MD

David Seidman, MD

11/23/04

Overview

Radiographs Classification Treatment Options Surgical Approaches

Radiographic Evaluation

From the lateral, acetabulum is inverted Y Anterior column Posterior column

Sciatic notch through obturator and inferior pubic ramus

AP

6 Lines Iliopectineal Ilioischial Posterior wall Anterior wall Dome Teardrop

Radiographs

AP

6 Lines Iliopectineal Ilioischial Posterior wall Anterior wall Dome Teardrop

Oblique

Iliac Oblique

Posterior column Anterior wall

Iliac Oblique

Posterior column Anterior wall

Iliac Oblique

Posterior column Anterior wall

Oblique

Obturator

Anterior column Posterior Wall

Obturator Oblique

The Dome

The Dome

Weight Bearing Dome:Roof arc angle

Vertical line through the rotational center of acetabulum

Angled line through the fracture

Mata: <45 deg on any view

Recently: anterior <25 Medial <45 Posterior <70

Top of the dome distally for 1 cm on CT

Classification: Letournel and Judet

Classification: Special Notes

Both column essentially a T

type occurring proximal to the joint

No portion of the articular surface is attached to axial skeleton

SPUR SIGN Division of

both columns ABOVE the acetabulum

Secondary congruence

AP view

Obturator oblique view

Iliac oblique view

Representative CT cuts of the fracture, demonstrating that approximately 50 percent of the posterior wall is affected.

Posterior Wall

Beware posterior hip dislocation

Sometimes completely unstable

Traction to maintain reduction until fixation

Osteochondral fx common: require fixation/reduction if in weight bearing portion

Biomechanics

Weight bearing portion: Primarily posterior and

superior Hip stable

<20% of posterior wall Hip unstable

>40% of posterior wall

Posterior Wall Fracture

Blood supply is from capsule: do not detach

Flip over leaving capsule if possible

Anterior column + posterior hemitransverse vs. T type

Reducing anterior column usually reduces posterior column, post capsule is not usually disrupted

In contrast, in the T type, reducing the anterior does not reduce the posterior and the post capsule is disrupted

T type

T type

T type

Must involve obturator foramen

Both Column

Both Column

Treatment options

Nonoperative Traction NWB Indicated if

displacement < 2mm

Operative ORIF ORIF w/ THA

Absolute indication is hip instability / subluxation out of traction

Operative vs. Non-op

Classic Articles Rowe and Lowell: non-

op is preferred Judet et. al: 90% good

result if anatomic reduction, 74% good result overall

Current Literature Rowe and Lowell

2 groups of fractures High energy forces,

incongruous joint Operative

management is better Low energy, minimal

displacement Non-op management

is satisfactory

Surgical Considerations

Timing Surgery should be

completed within 7 d results deteriorate

after 3 weeks

Approaches Iliofemoral Ilioinguinal Kocher-Langenbach Triradiate Extended Iliofemoral Combined

Iliofemoral

Anterior column or anterior wall fractures w/ displacement cephalad to hip joint

Lag screws into anterior column Plate only fits on crest of ilium, not on

pelvic brim

Ilioinguinal

For anterior fractures where access to entire anterior column

Can be used for both column fx only if posterior piece is large and intact

Don’t see articular surface, only fx lines in pelvis

Commonly sacrifice lateral cutaneous nerve of the thigh

Divide external oblique from inguinal ring to asis, expose spermatic cord/round ligament

Ligate inferior epigastric vessels

Ilioinguinal

Complications: Femoral nerve injury LFCN Thrombosis in femoral

vessels

Ilioinguinal

Sling 1: iliopsoas Sling 2: external iliac

artery and vein (aka femoral sheath)

Sling 3: spermatic cord

Kocher-Langenbach

Isolated posterior wall or posterior column injuries only

Exposure limited superiorly by superior gluteal vessels and greater trochanter

High incidence of HO and sciatic injury

May consider troch osteotomy

Complications: Sciatic nerve 2-10% Damage to femoral

head blood supply via medial femoral circumflex a.

Triradiate

Both column fractures ASIS to top of sciatic

notch is exposed Expose TFL, divide

TFL and G. max Remove greater troch Capsulorrhaphy and

joint exposure

Extended iliofemoral

Exposes Outer table of ilium Superior dome Posterior column Anterior column to

iliopubic eminence Provides exposure to

bone above sciatic notch

Highest risk for HO Also risk for superior gluteal artery

injury leading to muscle necrosis

Approach by fracture type

Kocher-Langenbach Posterior column

Prone is best Weight of leg in lateral

position causes rotation of posterior column

Posterior wall Lateral is OK

Posterior column + posterior wall

Prone is best

Anterior column + posterior hemitransverse Ilioinguinal approach

usually adequate

Transverse fxs Depends on location

of displacement T type is most difficult

Approach by fracture type

Both Column If posterior column is a

single large fragment, then ilioinguinal approach is preferred

If posterior column is not reduced, then add Kocher-Langenbach

If significant posterior wall fracture, choose extensile or combined approach

Reduction

Traction Fracture table Direct pull on femoral

neck Corkscrew into femoral

neck T handled bone hook

on greater troch

External distractors

5 or 6 mm Schanz threaded pin through the ischial tuberosity as joystick for T type or posterior column fxs

Farabeuf clamps on screws inserted on either side of fx

Reduction

Cerclage wires may help through the greater or lesser sciatic notch

Fixation

Interfrag lag screws 3.5 mm cortical

screws, even in cancellous bone

No tap necessary except in dense bone of sciatic butress

3.5 mm recon plate contoured

Outcomes

THA after ORIF of acetabulum does better than THA after unreduced acetabulum fx

Complications

Thromboembolism: 60% of cases

HO Use XRT or indomethacin

peri/post op for prophylaxis w/ Kocher-Langenbach approach

Neurologic injury AVN

18% of posterior fracture patterns

Post-traumatic DJD Abductor weakness Intra-articular

hardware