OVERVIEW
· Acetabular fractures are complex intra-articular injuries of the hip joint associated with significant morbidity.
· They most commonly result from high-energy trauma such as motor vehicle collisions or falls from height.
· The fracture pattern is determined by the position of the hip and the direction of the applied force at the time of injury.
· Axial loading of a flexed hip, classically described as a dashboard injury, is the most common mechanism.
CLINICAL EVALUATION
· Patients typically present with acute hip pain, inability to bear weight, and functional impairment.
· In posterior fracture-dislocations, limb shortening and rotational deformity may be evident.
· A thorough neurovascular examination is mandatory.
· Sciatic nerve injury is particularly associated with posterior dislocations, with the peroneal division most commonly affected.
IMAGING – PLAIN RADIOGRAPHS
· Initial evaluation relies on standard radiographs, including an anteroposterior pelvis view, obturator oblique view, and iliac oblique view.
· On the AP pelvis view, the six cardinal lines of the acetabulum should be assessed.
· The obturator oblique view profiles the anterior column and posterior wall.
· The iliac oblique view profiles the posterior column and anterior wall.
· The obturator oblique view is critical to ensure that screws placed in the anterior column do not penetrate the hip joint.
SYSTEMATIC RADIOGRAPHIC EVALUATION
· The iliopectineal and ilioischial lines are evaluated together.
· If both lines are intact, a posterior wall fracture is likely.
· If only one line is disrupted:
Iliopectineal line : disruption suggests an anterior wall or anterior column fracture.
Ilioischial line : disruption suggests a posterior column fracture with or without posterior wall involvement.
If both lines are disrupted, the obturator ring is examined.
If the obturator ring is disrupted, the iliac wing is evaluated.
An intact iliac wing suggests a T-type fracture.
A disrupted iliac wing suggests an anterior column/posterior hemitransverse fracture or a both-column fracture.
COMPUTED TOMOGRAPHY
· Computed tomography is essential for evaluating posterior injuries, intra-articular fragments, marginal impaction, and hip joint congruency.
· Thin-cut (1–2 mm) axial CT scans and three-dimensional reconstructions with femoral subtraction are critical for surgical planning.
· On axial CT:
Vertical fracture lines suggest transverse or T-type fractures.
Horizontal fracture lines indicate column fractures.
Sequential axial images demonstrating no intact osseous connection between the acetabular articular surface and the axial skeleton through the sacroiliac joint indicate a both-column fracture.
CLASSIFICATION (LETOURNEL–JUDET)
· Simple fracture patterns:
Posterior wall (most common)
Posterior column
Anterior wall
Anterior column
Transverse
· Associated fracture patterns:
Posterior column with posterior wall
Transverse with posterior wall
T-type
Anterior column with posterior hemitransverse
Both-column fracture (most common associated type)
In both-column fractures, the acetabular dome is completely dissociated from the intact ilium, and the spur sign may be seen on the obturator oblique view.
TREATMENT – GENERAL PRINCIPLES
· The primary goals of treatment are restoration of articular congruity and hip stability.
· Preservation of the femoral head blood supply is critical.
· Deep vein thrombosis screening and prophylaxis are mandatory.
· During surgery, positioning the hip in extension and the knee in flexion reduces tension on the sciatic nerve.
· Postoperatively, patients are typically restricted to touch-down weight bearing.
NONOPERATIVE MANAGEMENT
· Indications include:
Less than 1 mm of articular step-off and less than 2 mm of gap
Roof arc angle of 45 degrees or greater (CT correlate: fracture at least 10 mm from the dome apex)
Stable posterior wall fractures involving less than 20–30% of the wall
In unstable injuries that are not surgical candidates, femoral traction for 2–3 weeks followed by toe-touch weight bearing may be considered.
OPERATIVE MANAGEMENT
· Indications include:
Articular displacement greater than 1 mm or gap greater than 2 mm
Roof arc angle less than 45 degrees
Posterior wall involvement greater than 20–30%
Intra-articular loose fragments
Irreducible fracture-dislocations
Early surgery within five days of injury is associated with improved reduction quality.
SURGICAL APPROACHES
· Kocher–Langenbeck approach:
Indicated for posterior wall, posterior column, transverse, transverse/posterior wall, and posterior column/posterior wall fractures.
· Ilioinguinal approach:
Indicated for anterior wall, anterior column, anterior column/posterior hemitransverse, and both-column fractures.
· Modified Stoppa approach:
Provides optimal exposure of the quadrilateral surface.
The corona mortis, present in 10–30% of patients, must be identified and ligated.
· Extensile approaches are reserved for fractures older than three weeks or complex associated patterns.
ORIF WITH ACUTE TOTAL HIP ARTHROPLASTY
· Relative indications include:
· Age greater than 60 years
· Superomedial dome impaction (gull sign
· Associated displaced femoral neck fracture
· Significant preexisting osteoarthritis
COMPLICATIONS
· Deep vein thrombosis and pulmonary embolism
· Heterotopic ossification
· Sciatic nerve injury
· Osteonecrosis of the femoral head
· Posttraumatic degenerative joint disease
· The most important prognostic factor is the quality of fracture reduction.