Acetabular FracturesAcetabular FracturesTreatmentTreatment

Muhammad Abdelghani

Goal of Treatment

The goal of treatment is anatomic restoration of the articular surface to prevent posttraumatic arthritis.

Initial Management

The patient is usually placed in skeletal traction to

1. allow for initial soft tissue healing, 2. allow associated injuries to be

addressed, 3. maintain limb length, & 4. maintain femoral head reduction

within the acetabulum.

Non-operative treatment

Indications: Displacement <5mm in the dome, or articular

step-off of <2mm (with maintanance of femoral head congruency out of traction, & absence of intraarticular osseous fragments).

N.B. If a fracture is displaced <2mm, no matter what the anatomical type, nonoperative treatment should yield good results.

Distal anterior column or transverse (infratectal) fractures in which femoral head congruency is maintained by the remaining medial buttress.

Maintenance of medial, anterior and posterior roof arcs >45° (indicating fracture stability).

Roof arcs

The medial, anterior, & posterior roof arcs are measured on AP, obturator oblique, and iliac oblique views, respectively.

The roof arc is formed by the angle between two lines, one drawn vertically through the geometric center of the acetabulum, the other from the fracture line to the geometric center.

Roof arc angles are of limited utility for evaluation of both column fractures and posterior wall fractures.

Roof Arc Angles

1. Medial Roof Arc (AP pelvis)

2. Anterior Roof Arc (Obturator oblique)

3. Posterior Roof Arc (Iliac oblique)

Roof arc measurement

Operative treatment Indications

Head unstable and/or incongruous Guidelines to be correlated to patient

factors.

Instability

Hip dislocation associated with: Posterior wall or column fractures

(posterior instability) Major anterior wall fractures (anterior

instability) Any fracture with significant size

quadrilateral plate fracture (Central instability)

Incongruity

Alteration or inconsistency in relationship between femoral head & acetabulum.

Incongruity of the hip may result in early degenerative changes & posttraumatic osteoarthritis.

Evaluation: Roof arc angle of MattaRoof arc measurement by CT.

Incongruity

Displaced dome fractures: surgery is usually necessary to restore the weight-bearing surface.

High transverse or T-type fractures These are shearing injuries that are grossly unstable when they involve

the superior, weight-bearing dome. Displaced both-column fractures (floating acetabulum): Surgery is

indicated for restoration of congruence if the roof fragment is displaced and secondary congruence cannot be obtained or if the posterior column is grossly displaced.

Retained osseous fragments may result in incongruity or an inability to maintain concentric reduction of the femoral head..

Femoral head fractures generally require ORIF to maintain sphericity and congruity.

Soft tissue interposition may necessitate operative removal of the interposed tissues.

Fractures through the roof or dome

Assessment of reduction

Assessment of reduction includes:

Restoration of pelvic lines. Concentric reduction on all 3 views. The goal of anatomic reduction.

Operative treatmentContraindications

Operative contraindications local or systemic infection, severe osteoporosis

Relative contraindications advanced age, associated medical conditions associated soft tissue and visceral injuries, multiply injured patient not stable for a big

acetabular surgery

Operative treatment Timing

Surgery should be performed within 2 weeks of injury.

It requires A well-resuscitated patient. Appropriate radiologic workup. Appropriate understanding of the

fracture pattern. Appropriate operative team.

Operative treatment Timing

Surgical emergencies include: Open acetabular fracture. New-onset sciatic nerve palsy after

closed reduction of hip dislocation. Irreducible posterior hip dislocation. Medial dislocation of femoral head

against cancellous bone surface of intact ilium.

Morel–Lavallé lesion (Skin Degloving Injury(

A closed degloving injury over the greater trochanter. Results from the blunt trauma that caused the

fracture. The subcutaneous tissue is torn away from the

underlying fascia, and a significant cavity results Cavity contains hematoma and liquified fat. These areas must be drained and debrided before or

during definitive fracture surgery to decrease the chance of infection.

Advisable to leave this area open through the surgical incision or a separate incision.

Dressing changes and wound packing are sometimes needed for a prolonged period of time.

Primary excision of the necrotic fat and closure over a drain has not been routinely successful.

Surgical Approaches

Kocher-Langenbeck (Posterior): best access to posterior column (prone)

ilioinguinal (Anterior): best access to anterior column and inner aspect of innominate bone (supine)

Extended iliofemoral (Lateral): best simultaneous access to the two columns (lateral)

Combined approaches performed concurrently or successively is less desirable

No single approach provides ideal exposure of all fracture types.

Proper preoperative classification of the fracture configuration is essential to selecting the best surgical approach.

Kocher-Langenbeck Approach

Kocher-Langenbeck Approach

Anatomische Skizze der Weichteilstrukturen bei Kocher-Langenbeck-Zugang

1 M. glutaeus maximus2 M. glutaeus medius3 M. glutaeus minimus4 M. piriformis5 M. gemellusSuperior6 M. obturatorius internus 7 M. gemellus inferior8 M. quadratus femoris9 Lig. Sacrotuberale10, N.,A.,V., glutea inferior11 N.,A.,V., glutea superior

Kocher-Langenbeck ApproachIndications

Posterior wall fractures Posterior column fractures Posterior column/posterior wall

fractures Juxtatectal/infratectal transverse or

transverse with posterior wall fractures

Some T-type fractures

Areas accessible by Kocher-Langenbeck approach

• Entire posterior column•Greater & lesser sciatic notches•Ischial spine•Retroacetabular surface•Ischial tuberosity•Ischiopubic ramus

The room is set up such that the x-rays and CT scans areavailable for viewing during the procedure. The patient isprone on a radiolucent table with SCD’s in place.

The affected extremity is positioned with a distal femoralpin to allow for traction on the table with the hip in slightextension and the knee flexed to relax the sciatic nerve.

The incision is midline over the femur, and angles posteriorly at the posterior aspect of the greater trochanter to end slightly superior to the posterior iliac spine.

The incision is midline over the femur, and angles posteriorly at the posterior aspect of the greater trochanter to end slightly superior to the posterior iliac spine.

GREATER TROCHANTER

The skin incision is brought down to the level of the tensorfascia lata, which is divided in line with the incision. Thegluteus maximus fascia is then divided.

GLUTEUS FASCIA

TENSORFASCIALATA

The gluteus maximus muscle is identified.

GLUTEUS MAXIMUS

The maximus muscle is gently separated digitally untilthe first traversing branches of the nerve are visible.

GLUTEAL NERVE BRANCH

Dividing the gluteus maximus too far proximally will denervate a significant portion of it.

GLUTEUS MAXIMUS

TROCHANTERIC BURSA

The trochanteric bursa is divided.

QUADRATUSFEMORIS

View of the deep musculature with the Charnley retractor in place.

VASTUS LATERALIS

GLUTEUSMEDIUS

SHORT EXTERNAL ROTATORS

With gentle retraction anteriorly of the gluteus medius, the piriformis tendon comes into view.

PIRIFORMIS

GLUTEUSMEDIUS

OBTURATOR INTERNIS PIRIFORMIS

After minimal dissection along the posterior aspect of the short external rotators the obturator internis tendon is identified between the gamelli.

TAG SUTURESBoth the piriformis and obturator internis are tagged and resectedapproximately 1cm away from their insertion in the femur. It is helpful before this is performed to identify the sciatic nerve in an area of healthy tissue, usually at the level of the quadratus femorus.

The piriformis and obturator internis are being gently elevated using the sutures.

OBTURATORINTERNIS

PIRIFORMIS

With the piriformis being held back digitally, the sciatic nerveis visualized running posterior to the obturator internis tendon.

OBTURATORINTERNIS

SCIATIC NERVE

Knowing that the nerve is safe and can be protected by the obturator internis muscle, a Letournel retractor, or blunt cobra, is placed anteriorly to the obturator internus tendon into the lesser sciatic notch.

Knowing that the nerve is safe and can be protected by the obturator internis muscle, a Letournel retractor, or blunt cobra, is placed anteriorly to the obturator internus tendon into the lesser sciatic notch.

BLUNT COBRARETRACTOR

OBTURATOR INTERNIS

SCIATICNERVE

Once in the lesser sciatic notch, posterior leverage on the retractorallows exposure of the posterior aspect of the acetabulum whileprotecting the nerve.

BLUNT COBRARETRACTOR

OBTURATOR INTERNIS

SCIATICNERVE

POSTERIOR ACETABULUM

FEMORALHEAD

DISPLACED POSTERIOR WALL

The femoral head and displaced portion of the posterior wall are easily identified.

After the fracture and fracture bed are cleaned, the posterior wall is reduced and fixed in place with a buttress plate.

After the fracture and fracture bed are cleaned, the posterior wall is reduced and fixed in place with a buttress plate.

REDUCED FRACTURE

Ilioinguinal approach

Ilioinguinal Approach

Weichteilstrukturen bei ilioinguinalem Zugang

1 M. psoas major2 M. iliacus3 Pecten ossis pubis4 A. iliaca communis5 A. iliaca interna6 A. iliaca externa7 Aa. Vv. Testiculares8 V. iliaca communis9 V. iliaca externa10 N. ilioinguinalis11 N. genitofemoralis12 N. obturatorius13 N. femoralis14 N. cutaneus femoris lateralis15 Ductus spermaticus16 Ductus deferens

Ilioinguinal ApproachIndications

Anterior wall Anterior column Transverse with significant anterior

displacement Anterior column/posterior

hemitransverse Both-column

Setup: The patient is supine on a radiolucent table with skeletal traction holding the affected extremity in slight flexion. A perineal post is used to allow for traction if needed.

Figure 6 Figure 7

ASIS

SYMPHYSIS

ASIS

A

The incision is drawn out. Figure A shows the location of the incision with respect to the symphysis and ASIS. Figure B shows the patient from the side as one would observe during surgery. The incision is curvilinear towards the posterior aspect of the ilium. The surgery begins by approaching the iliac crest along the area shown in figure B.

B

ASIS

SYMPHYSIS

ASIS

Figure 6 Figure 7

The incision is drawn out. Figure A shows the location of the incision with respect to the symphysis and ASIS. Figure B shows the patient from the side as one would observe during surgery. The incision is curvilinear towards the posterior aspect of the ilium. The surgery begins by approaching the iliac crest along the area shown in figure B.

Sharp retractors are used to identify the interval between the abductor and abdominal musculature.

The iliac crest is indicated by purple lines. The interval between theabdominal and abductor musculature occurs towards the posterioraspect of the iliac crest as the abdominal musculature hangs overthe crest (dotted line)

The interval is taken with a Bovie down to the iliac crestand the abdominal musculature is reflected anteriorly.

Closeup of previous image.

After the iliacus is released from the inside of the ilium a large key elevator is used to elevate subperiosteally to the SI joint.

ILIUM

ILIACUS

After this dissection is complete, the posterior aspect of theiliac fossa is packed off with a lap and attention to broughtto the anterior portion of the incision.

Gelpi retractors are used to retract the skin and softtissue after the external oblique fascia is identified.

EXTERNAL OBLIQUEFASCIA

The external oblique fascia is divided in line withthe incision and the fascia is reflected distally.

EXTERNALOBLIQUEFASCIA

VAS DEFERENS, SPERMATIC CORD, + ILIOINGUINAL NERVE

EXTERNALOBLIQUEFASCIA

INGUINAL LIGAMENT

EXTERNALOBLIQUE

FASCIA

After this is performed, the vas deferens, spermatic cord, and ilioinguinal nerve are identified and protected with a Penrose drain. Allis clamps areused to retract the the external oblique fascia.

VAS DEFERENS SPERMATIC CORD ILIOINGUINAL NERVE

EXTERNALOBLIQUEFASCIA

INGUINAL LIGAMENT

EXTERNALOBLIQUE

FASCIA

It is helpful to include some subcutaneous tissue in the clamps to protect the external oblique fascia from tearing. This exposes the inguinal ligament, which is a reflection of the external oblique fascia.

An incision is made in the inguinal ligament, allowing 1 to 2mm of the ligament to reflect medially with themusculature (dotted line).

Incision through the inguinal ligament.

ASIS

LATERAL FEMORALCUTANEOUS NERVE

ASIS

LATERAL FEMORALCUTANEOUS NERVE

As the dissection extends toward the ASIS, one needs to identify the lateral femoral cutaneous nerve, which is immediately under the inguinal ligament.

ASIS

LATERAL FEMORALCUTANEOUS NERVE

The nerve is typically located approximately 1cm medialto the ASIS but is variable and may be more than one branch.

ASIS

PSOAS FEMORALNERVE

ILIOPECTINEALFASCIA

EXTERNALILIAC

VESSELS

ASIS

PSOAS FEMORALNERVE

ILIOPECTINEALFASCIA

EXTERNALILIAC

VESSELS

At this point, the identification of the iliopectineal fascia is performed,allowing for retraction of the exteral iliac vessels and lymphatics medially.

ASIS

PSOAS FEMORALNERVE

ILIOPECTINEALFASCIA

EXTERNALILIAC

VESSELS

The psoas muscle and femoral nerve are retractedlaterally. The army-navy retractor protects the vasculature while the Allis clamp is holding the iliopectineal fascia.

TRUE PELVIS

ILIOPSOASMUSCLE

FEMORAL NERVE

ILIOPECTINEALFASCIA

Closeup of previous image.

PSOAS FEMORAL NERVE

Closeup of the iliopectineal fascia demonstrating the psoas and femoralnerve on the lateral side of the fascia in the false pelvis. The true pelvisis located medial to the iliopecineal fascia over the pelvic brim.

PSOAS FEMORAL NERVE

Once the iliopectineal fascia is excised, access to the true pelvis isobtained. The medial window of the approach is utilized when buttressplating to the symphyseal body or symphyseal fixation is necessary.

PSOAS FEMORAL NERVE

In this case, the reduction and fixation was performed through only the lateral and middle windows.

LATERAL FEMORALCUTANEOUS NERVE

ILIAC FRACTURE

View from the opposite side of the table demonstrating the lateral window and iliac wing fracture.

PSOASLATERAL FEMORALCUTANEOUS NERVE

VESSELS

PELVIC BRIM

View of the middle window demonstrating the pelvic brim.

PSOASLATERAL FEMORALCUTANEOUS NERVE

VESSELS

PELVIC BRIM

View of the middle window demonstrating the pelvic brim.

The following sequence will demonstrate the view from the surgeon’s side of the table.

SI JOINT

ILIOPSOAS

This figure demonstrates the lateral window and exposure of the anterior column from the iliac crest and SI joint proximally to the psoas gutter and pelvic brim distally.

PELVICBRIM

PSOAS

VESSELS

This figure demonstrates the pelvic brim and displacementof the fracture as seen through the middle window.

PELVICBRIM

PSOAS

VESSELS

This figure demonstrates the pelvic brim and displacementof the fracture as seen through the middle window.

SUPERIOR RAMUSFRAGMENT

DISPLACED ANTERIORCOLUMN

Closeup of the fracture.

SUPERIOR RAMUSFRAGMENT

DISPLACED ANTERIORCOLUMN

Closeup of the fracture.

Extended iliofemoral approach

Extended Iliofemoral Approach

Operationssitus bei erweitertem iliofemoralen Zugang

1 M. gemellus superior2 M. obturatorius internus3 M. gemellus inferior4 M. piriformis5 M. quadratus femoris6 Sehne des M. obturatorius externus7 Tuber ischiadicum8 A. circumflexa femoris medialis, tiefer Abzweig9 N. ischiadicus

Extended iliofemoral approach Indications

Transtectal transverse + posterior wall or T-shaped fractures

Transverse fractures with extended posterior wall

T-shaped fractures with wide separations of the vertical stem of the ‘T’ or those with associated pubic symphysis dislocations

Certain associated both column fractures Associated fracture patterns or

transverse fractures operated on >21 days following injury

Extended iliofemoral approach

Extended iliofemoral approach has the highest incidence of ectopic bone formation (HO) and longest postoperative recovery

Other approaches

Stoppa approach (supine): Allows access to the medial wall of acetabulum, quadrilateral surface, & sacroiliac joint

Triradiate approach (prone): Alternate exposure to the external aspect of innominate bone, with almost same exposure as iliofemoral but visualization of the posterior part of ilium is not as good

Reduction Techniques

Special instruments. Essential instruments include pointed

fracture forceps, reduction clamps, fracture pushers, and other standard fracture clamps.

Special pelvic reduction clamps are extremely helpful. The pelvic reduction clamp is screwed directly to the bone using two 4.5-mm cortical screws or 6.5-mm cancellous screws. This clamp can be extremely helpful by applying direct forces to the fracture.

Reduction Techniques

Traction. Traction on the femoral head is

essential in obtaining a reduction. Traction may be obtained by the use

of a traction table, which must be adaptable, allowing the prone as well as the supine position.

An unscrubbed surgeon or technician is needed to control the leg rotation.

Helpful Hints for Reduction

The articular surface of the joint must be adequately visualized by a wide capsulorrhaphy in most cases.

Helpful Hints for Reduction

Most patients can be managed without a traction table, but direct traction on the femoral head is essential. This can be obtained by: a corkscrew in the femoral neck

to allow better retraction of the femoral head and visualization of the articular surface.

A sharp hook over the greater tuberosity can give the same effect.

Helpful Hints for Reduction

A 5- or 6-mm Schantz pin with a T-handle should be inserted into the ischial tuberosity in high transverse or T-type fractures to allow rotation of the posterior column, which in some instances cannot be reduced by any other method.

Helpful Hints for Reduction Holes should be drilled to accept the pointed forceps.

Helpful Hints for Reduction

Washers with extensions have been developed for use with the pointed forceps.

Helpful Hints for Reduction

Work within the fracture. In visualizing impacted fragments from

either an anterior or posterior approach, it is important to move the major fracture out of the way so that the impacted fragment can be visualized.

This is akin to the tibial plateau fracture where the lateral fragment is retracted like a book to allow reduction of the impacted fragment.

Therefore, work within the fracture where possible.

Marginally impacted fractures must be reduced in this way.

Cerclage wires

Cerclage wires inserted through the greater sciatic notch and around the anterior inferior iliac spine may greatly facilitate derotation & reduction of the columns, esp. if either the posterior or anterior column is “high” on the greater sciatic notch

ImplantsScrews

– 6.5-mm cancellous lag screws– 4.0-mm cancellous lag screws and 3.5 mm

cortical screws (lengths up to 120 mm)– 6.5-mm fully threaded cancellous screws

For fixation of the plate to bone, fully threaded cancellous screws are desirable, the 6.5-mm screw for the large reconstruction plate (4.5-mm) and the 3.5-screw for the 3.5-mm reconstruction plate.

Cannulated screws may also be helpful.

ImplantsPlates

A 3.5-mm reconstruction plate is the implant of choice for acetabular reconstruction.

These plates can be molded in two planes and around the difficult areas such as the ischial tuberosity.

Also, precurved 3.5-mm plates are available for anterior column fixation.

These plates are fixed with the 3.5-mm cancellous screws. In large individuals, and in pelvic fixation, the 4.5-mm

reconstruction plates are also useful, with fixation by the 6.5-mm fully threaded cancellous screws; however, they are rarely used at this time.

The 3.5-mm and 4.5 mm reconstruction plates for pelvic fixation

Plates Sites of Application

The plates may be applied to the anterior column from the inner table of the ilium to the symphysis pubis.

Plates may also be applied to the posterior column and the superior aspect of the acetabulum.

The distal screw should be anchored in the ischial tuberosity.

Great care should be taken to ensure that screws in the central portion of the plate do not penetrate the articular cartilage of the acetabulum.

In most instances, no screws should be put into that danger area, but if screws are necessary for stable fixation, they should be directed away from the joint. Screws within the joint are a not uncommon cause of chondrolysis.

Plates may be nested to buttress small fragments.

Internal fixation

Stable fixation is best achieved by interfragmental compression using lag screws.

After provisional fixation of all fractures with K-wires, or cerclage wires, screw fixation of the fractures is essential. The joint must be visualized at all times to ensure that anatomical reduction has been achieved and that no screw penetrates the articular cartilage.

After fixation by interfragmental lag screws, plates may be used to neutralize the fracture.

Plates may be placed either on the anterior or posterior column, depending on the approach.

Internal fixation

Adequate contouring of the plates is essential. Otherwise, displacement of the opposite column may occur.

Postoperative Care Indomethacin or irradiation: for heterotopic ossification

prophylaxis. A variety of treatments has been proposed to decrease the

amount of heterotopic bone including the use of diphosphonates, radiation and indomethacin. Diphosphonates prevent the mineralisation of osteoid, but this begins

again after withdrawal of the drug, and their use has been questioned.

There have been several reports of the use of indomethacin after operation for acetabular fractures.

Local radiation therapy has also been used after reports of successful results in hip arthroplasty.

Chemical prophylaxis, sequential compression devices, and compressive stockings for thromboembolic prophylaxis.

Mobilization out of bed is indicated as associated injuries allow.

Full weight bearing on the affected extremity should be withheld until radiographic signs of union are present (generally by 8-12 weeks postoperatively).

Complications Surgical wound infection: Risk is increased secondary to the

presence of associated abdominal and pelvic visceral injuries. Nerve injury

Sciatic nerve: Kocher-Langenbach approach with prolonged or forceful traction. Femoral nerve: Ilioinguinal approach may result in traction injury to femoral nerve.

Rarely, the nerve may be lacerated by an anterior column fracture. Superior gluteal nerve: most vulnerable in the greater sciatic notch. Injury during

trauma or surgery may result in paralysis of hip abductors with severe disability. Heterotopic ossification: Incidence is highest with extended

iliofemoral approach and second highest with Kocher-Langenbach. The highest risk is a young male patient undergoing a posterolateral extensile approach in which muscle is removed.

Avascular necrosis: This devastating complication occurs mostly with posterior types associated with high-energy injuries.

Chondrolysis: This may occur with or without surgical intervention, resulting in posttraumatic osteoarthritis. Concentric reduction with restoration of articular congruity may minimize this complication.

Thromboembolic complications

Case Study

Case Study

An 18-year-old woman was inadvertently struck on the lateral aspect of the hip by a police officer while marching in a homecoming parade.

Case Study

Obturator oblique view

Iliac oblique view

AP, obturator oblique, and iliac oblique views show a both-column acetabular fracture

The obturator oblique view shows the pathognomonic "spur-sign." Note that the spur represents the iliac wing fragment, or the constant fragment, and the entire acetabulum has been medialized. None of the dome of the acetabulum remains attached to the iliac wing.

Case Study

Two- and three-dimensional CT scans show an ipsilateral disruption of sacroiliac joint and extreme comminution through the dome of the acetabulum.

Case Study

Two- and three-dimensional CT scans show an ipsilateral disruption of sacroiliac joint and extreme comminution through the dome of the acetabulum.

This patient also had disruption of the pubic symphysis, creating an ipsilateral unstable hemipelvis with a both-column acetabular fracture.

Case Study

Final Reconstruction

Case Study

Postoperative radiographs showing anatomic reduction of the hemipelvis along with anatomic reduction of the acetabular fracture. In high-energy trauma injuries such as this, stability of the hemipelvis must be obtained first, by stabilizing the anterior and posterior aspects of the pelvis, after which the acetabular fracture is addressed. Anatomic alignment of the pelvic inlet and outlet should also be regained before the articular component of the injury (acetabular fracture) is addressed.

MCQ 1

Which two quadrants of the acetabulum are most at risk for injury by screws during fixation of total hip arthroplasty (THA):a) Anterior-inferior and posterior-superior b) Anterior-superior and posterior-superior c) Anterior-superior and anterior-inferior d) Anterior-superior and posterior-inferior e) Posterior-superior and posterior inferior

Answer 1

Which two quadrants of the acetabulum are most at risk for injury by screws during fixation of total hip arthroplasty (THA):a) Anterior-inferior and posterior-superior b) Anterior-superior and posterior-superior c) Anterior-superior and anterior-inferior d) Anterior-superior and posterior-inferior e) Posterior-superior and posterior inferior

Explanation The acetabular quadrant system described by Wasielewski

and colleagues is useful for determining the location of planned acetabular screw fixation in THA to avoid neurovascular complications. The quadrants are formed by drawing a line from the anterior-superior iliac spine through the center of the acetabulum and bisecting that line at the center of the acetabulum to form four equal quadrants. The line from the anterior-superior iliac spine to the center of the acetabulum serves as the dividing line between anterior and posterior, and the bisecting line as the division between superior and inferior.

In cadaver studies, the posterior-superior and posterior-inferior quadrants were shown to have the thickest bone and best potential for obtaining secure fixation with the least risk for injury to vessels. The anterior-superior quadrant (the quadrant of death) and the anterior-inferior quadrant were shown to be the most dangerous quadrants for fixation due to the thin bone and close proximity of the vessels to bone in that region.

MCQ 2 Criteria for nonoperative management of an

acetabular fracture includes all of the following except:

a) Stability demonstrated by dynamic stress radiographs

b) Femoral head subluxation of 3 mm c) Congruence of the femoral head with the

unaffected acetabular roof on the anteroposterior and Judet views

d) Roof arc measurement of greater than or equal to 45°

e) Unbroken computerized tomography arc at 10 mm from subchondral bone

Answer 2 Criteria for nonoperative management of an

acetabular fracture includes all of the following except:

a) Stability demonstrated by dynamic stress radiographs

b) Femoral head subluxation of 3 mm c) Congruence of the femoral head with the

unaffected acetabular roof on the anteroposterior and Judet views

d) Roof arc measurement of greater than or equal to 45°

e) Unbroken computerized tomography arc at 10 mm from subchondral bone

Explanation The outcome of nonoperative treatment of

acetabular fractures depends on the stability of the hip, the concentricity of the head of the femur under the roof of the acetabulum, and the condition of the roof itself.

Nonoperative criteria include roof arc measurement of at least 45°, unbroken subchondral computerized tomography arc of 10 mm, stability of the joint on stress radiographs, and congruence off the femoral head with the unaffected acetabular roof on all three views, anteroposterior and both Judet radiographs.

Any subluxation reduces the likelihood of a good result.

References

Jimenez ML: Classification of Acetabular Fractures. Medscape.com

Moore KD, Goss K, Anglen JO: Indomethacin versus radiation therapy for prophylaxis against heterotopic ossification in acetabular fractures. J Bone Joint Surg [Br] 1998;80-B:259-63.

Rommens PM, Hessmann MH: Azetabulumfrakturen. Unfallchirurg 1999; 102: 591-610