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

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

Must involve obturator foramen

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