• An acetabular fracture is a break in the socket portion of the “ball-and-socket” hip joint.
• These fractures are commonly the result of high-velocity trauma and are often complex.
• Fracture patterns are categorized as elementary (involving a single fracture line) or associated (a combination of fractures).

Comment

• CT scans are the imaging study of choice for detailed evaluation of acetabular fractures.
• Associated injuries are common, including sciatic nerve injury, which occurs in about 10% of cases.
• Complications can include post-traumatic arthritis, avascular necrosis of the femoral head, and myositis ossificans.

• Ebraheim, N.
• YouTube
• 2011

• Subluxation is a partial dislocation where the femoral head is no longer perfectly centered in the acetabulum but maintains some contact.
• Superomedial subluxation describes the displacement of the femoral head in an upward and inward direction relative to the acetabulum.
• This is often seen in conjunction with acetabular fractures where the medial and superior walls are compromised.

Comment

• A break in Shenton’s line, an imaginary arc drawn along the inferior border of the superior pubic ramus and the inferomedial aspect of the femoral neck, is a radiographic indicator of subluxation.
• Traumatic hip dislocations are most often associated with high-speed trauma, such as motor vehicle collisions.
• Central dislocation, where the femoral head is driven medially into the pelvis, is always associated with an acetabular fracture.

• Kraeutler, M. J., et al.
• PubMed Central
• 2023

• A “teardrop” or “pear-shaped” bladder refers to the radiographic appearance of the urinary bladder when it is compressed and elongated by an external process.
• The base of the bladder appears narrowed, and the body is elongated vertically.

Comment

• This sign was originally described in the context of pelvic hematoma secondary to pelvic fractures.
• The compression is caused by the accumulation of blood in the extraperitoneal space surrounding the bladder.
• Other causes for this appearance include pelvic lipomatosis, enlarged lymph nodes, iliac artery aneurysms, and inferior vena cava obstruction.

• Ambos, M. A., et al.
• Radiology
• 1977

• A collection of blood within the retroperitoneal or extraperitoneal space of the pelvis.
• In the context of trauma, it is a common result of pelvic fractures with associated vascular injury.

Comment

• Pelvic hematoma is the classic cause of the teardrop bladder sign due to extrinsic compression of the bladder walls.
• Contrast-enhanced CT is the gold standard for identifying the source of vascular bleeding within a pelvic hematoma.
• Management is complex and depends on the hemodynamic stability of the patient, with options ranging from angiographic embolization to pre-peritoneal packing.

• Iancu, C., et al.
• ResearchGate
• 2018

• A fracture is a partial or complete disruption in the continuity of a bone.
• A blunt trauma fracture specifically results from a significant, non-penetrating force applied to the body.
• In high-energy trauma, such as a motor vehicle collision, this can lead to complex fracture patterns.
• Acetabular fractures are breaks in the socket portion of the hip joint.

• The primary etiology is high-energy trauma.
• This includes motor vehicle collisions, which are a principal cause of acetabular and pelvic fractures.
• Other causes include pedestrian-vehicle incidents, falls from a significant height, and crush injuries.
• The fracture pattern is determined by the direction and magnitude of the applied force.
• The position of the femoral head at impact also influences the fracture pattern.
• The patient’s bone quality is another determining factor.

• High-energy forces are transmitted through the skeleton.
• These forces overwhelm the bone’s capacity to absorb energy, leading to a fracture.
• In acetabular fractures, the femoral head is driven into the acetabulum, causing it to break.
• The specific pattern—such as anterior column, posterior column, or transverse fractures—is dictated by the vector of this force.
• Disruption of the pelvic ring can increase the internal pelvic volume.
• This reduces the tamponade effect of the retroperitoneum.
• This can lead to significant hemorrhage from the extensive venous plexuses and arterial supply in the region.

• The structural consequence is a loss of skeletal integrity.
• This can range from a simple, non-displaced fracture to a highly comminuted and displaced fracture with multiple fragments.
• Acetabular fractures disrupt the articular surface of the hip joint.
• This can potentially lead to joint incongruity and instability.
• These fractures are classified based on the involvement of the anterior and posterior columns and walls of the acetabulum.
• Systems like the Judet and Letournel classification are used.
• Associated hip dislocations are common.

• Functionally, these fractures cause significant pain.
• They also lead to a loss of mobility.
• A key determinant of long-term function is the quality of the articular reduction.
• An anatomic reduction is crucial for minimizing the risk of post-traumatic osteoarthritis.
• Even with successful treatment, patients may experience long-term complications.
• These complications include hip muscle weakness, altered gait, and chronic pain.
• Patients may also experience an inability to return to their previous level of activity.
• Sexual and urinary dysfunction can also occur, impacting quality of life.

• Initial radiographic evaluation in the trauma bay often includes an anteroposterior (AP) pelvis X-ray.
• This is to screen for fractures.
• Computed tomography (CT) is the gold standard for definitive diagnosis and preoperative planning.
• CT provides detailed visualization of fracture patterns, fragment displacement, and associated soft tissue injuries.
• CT angiography is indicated when there is concern for active arterial bleeding.
• Specialized radiographic views, such as Judet views (iliac and obturator oblique), may be used for further characterization of acetabular fractures.

• In the setting of high-energy trauma, initial laboratory evaluation is critical.
• This is for assessing hemodynamic stability and end-organ perfusion.
• Essential tests include a complete blood count (CBC) to establish a baseline hemoglobin and hematocrit.
• A type and crossmatch is needed for potential blood transfusion.
• Coagulation studies, including prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT), are necessary.
• These evaluate for traumatic coagulopathy.
• A serum lactate level serves as a marker of systemic hypoperfusion and shock.

• Initial management follows Advanced Trauma Life Support (ATLS) protocols.
• This focuses on resuscitation and stabilization.
• Hemodynamically unstable patients with pelvic fractures may require a pelvic binder.
• This reduces pelvic volume and controls venous hemorrhage.
• Definitive treatment for displaced acetabular fractures is typically surgical.
• Open reduction and internal fixation (ORIF) is performed to achieve anatomic reduction of the articular surface and stable fixation with plates and screws.
• In some cases, particularly in older patients with significant comminution or pre-existing arthritis, an acute total hip arthroplasty (THA) may be indicated.
• Non-operative management with protected weight-bearing is reserved for non-displaced or minimally displaced, stable fractures.

• The prognosis is multifactorial.
• It depends on the severity of the fracture.
• It depends on the quality of surgical reduction.
• It depends on the patient’s age.
• It depends on the presence of associated injuries.
• Anatomic reduction is a critical factor for achieving good to excellent functional outcomes.
• Complications can significantly affect the prognosis.
• These include post-traumatic osteoarthritis, avascular necrosis of the femoral head, and sciatic nerve injury.
• Other complications are heterotopic ossification, deep vein thrombosis, and infection.
• Mortality from pelvic fractures is often related to associated hemorrhage or other systemic injuries rather than the fracture itself.

• Etymology

• Trauma: From the Greek word *trauma*, meaning “wound.” It reflects the physical and psychological injury resulting from an external force.
• Fracture: Derived from the Latin word *fractura*, meaning “a breach or cleft,” and from *frangere*, “to break,” accurately describing the disruption in the continuity of bone.
• Acetabulum: A Latin term literally meaning “vinegar cup,” a name given due to the resemblance of the hip socket to the small cups used for serving vinegar in ancient Rome.
• 
• Subluxation: From the Latin prefix *sub*, meaning “under” or “less than,” and *luxatio*, meaning “dislocation.” It denotes a partial dislocation where the joint surfaces are still in partial contact.
• Bladder: Originates from the Old English *blǣdre*, referring to a “blister” or “bladder,” which shares roots with the Proto-Germanic *bladron*, meaning “to blow up.”

• AKA / Terminology

• Dashboard Injury: This term is often used to describe the mechanism of a posterior wall acetabular fracture, where the flexed knee strikes the dashboard during a head-on collision, transmitting force through the femur to the hip socket.
• Open-Book Pelvic Fracture: A term for severe pelvic ring injuries, often from high-energy anterior-posterior compression forces (like in some MVCs), where the pelvis opens like a book, leading to life-threatening hemorrhage.
• Letournel-Judet Classification: The foundational system for classifying acetabular fractures, developed by French surgeons Robert Judet, Jean Judet, and Emile Letournel in 1964. It divides fractures into elementary (simple) and associated (complex) patterns, which is crucial for surgical planning.

• Historical Notes

• Pre-20th Century: Before the advent of automobiles and modern surgical techniques, severe pelvic and acetabular fractures were often fatal due to hemorrhage and lack of effective treatment.
• The Rise of the Automobile: The early 20th century saw a dramatic increase in high-energy trauma due to motor vehicle collisions. Early efforts to address this were often based on “folklore” rather than scientific evidence, with significant declines in fatalities only occurring after the 1970s with the implementation of scientifically evaluated safety measures.
• Radiographic Era: The discovery of X-rays was a monumental leap, allowing for the first time a non-invasive view of the bony injury, which was critical for diagnosis and planning treatment. The Judet views (oblique X-rays) were specifically developed to better visualize the columns of the acetabulum.
• Surgical Evolution: The work of Judet and Letournel in the mid-20th century revolutionized the treatment of acetabular fractures by providing a detailed anatomical understanding and advocating for open reduction and internal fixation (ORIF) to restore joint congruity. More recent developments have focused on minimally invasive surgical techniques.
• Bladder Injury: The diagnosis of bladder rupture has evolved from clinical suspicion to the use of retrograde cystography, and now commonly CT cystography, to precisely identify the location and extent (intraperitoneal vs. extraperitoneal) of the injury.

• Cultural or Practice Insights

• The Golden Hour: The concept of the “golden hour” in trauma care, emphasizing rapid response and treatment to improve outcomes, became a cornerstone of modern emergency medical systems, driven by the frequency of severe injuries from MVCs.
• Risk Compensation: An observed phenomenon where safety improvements (like better brakes or seatbelts) can sometimes lead to more aggressive driving behaviors, partially offsetting the safety gains.
• Trauma as a Public Health Issue: Initially viewed as random “accidents,” high-energy trauma from MVCs is now understood as a major public health problem, with predictable patterns and preventable causes. This shift led to advancements in vehicle safety, road design, and traffic laws.
• The “Accident”: The term “accident” is increasingly falling out of favor among safety organizations, who prefer “collision” or “crash” to remove the connotation of randomness and emphasize that these events are often preventable.

• Notable Figures or Contributions

• Robert Judet, Jean Judet, and Emile Letournel: French orthopedic surgeons who pioneered the anatomical study and surgical treatment of acetabular fractures. Their classification system remains the standard worldwide for understanding and treating these complex injuries.
• Joseph-François Malgaigne: A 19th-century French surgeon who described a vertically unstable pelvic fracture pattern, now known as the “Malgaigne fracture,” a historically significant eponymous term in pelvic trauma.
• Chip Routt, MD: A prominent orthopedic trauma surgeon who has contributed significantly to the modern management of pelvic ring injuries, including techniques for reducing open-book (APC) fractures.

• Artistic Representations

• Painting:
  • Guernica (1937) by Pablo Picasso, while depicting the horrors of war, uses fragmentation and distorted forms to convey the shattering impact of violent trauma on the body and psyche.

•  
  • The works of John Singer Sargent, such as Gassed (1919), portray the human cost and aftermath of physical trauma.
• Sculpture:
  • Artists like Doris Salcedo use sculpture to address the trauma of political violence and loss, conveying pain through material form.
  • The experience of physical trauma and the body’s fragility is a theme explored by many contemporary artists.
• Photography:
  • Historical photographs from the 1920s and 1930s document the raw reality of early automobile collisions, serving as a stark reminder of the dangers before modern safety advancements.
  • 
  • Contemporary photojournalism continues to capture the immediate aftermath of MVCs.
• Literature:
  • The “car crash” novel is a subgenre of fiction where a collision serves as a pivotal, often life-altering event for the characters.
  • Ross Hamilton’s philosophical and literary history, Accident, explores how accidental events, including physical trauma, have shaped modern consciousness and narrative.
• 
• Poetry:
  • Poetry can explore the themes of suddenness, pain, and the journey of healing after a traumatic injury, capturing the emotional and physical landscape of recovery.
• Song/Music:
  • Songs like “American Idiot” by Green Day and
  •  
  • “Mr. Brightside” by The Killers have been noted for their high tempo (over 120 BPM), which some studies suggest may correlate with more aggressive driving behaviors.
  • Thematic explorations of crashes and their aftermath appear in various musical genres.

• Quotes and/or Teaching Lines

• “Injury is the prelude to insight.”
• “I joke, but I only half joke, that if you come to one of our hospitals missing a limb, no one will believe you till they get a CAT scan, MRI, or orthopedic consult.” – Abraham Verghese.
• “Fracture reduction is very important… we should have that good proprioceptive skills and a three-dimensional orientation like from where the screw is going and where it’s exiting.”
• “Every healed fracture is a testament to the spirit.”

• Poem

A Sudden Force, a Chassis Crushed

A sudden force, a chassis crushed, a life held in suspense,
Where steel and bone in concert failed, a violent confluence.
The *acetabulum’s* Latin cup, no longer holds its guest,
The femoral head subluxed and high, put to a brutal test.

A *dashboard injury’s* classic sign, the fracture lines descend,
A “teardrop” bladder, torn and breached, where pelvic walls now rend.
The Judet map of columns broke, a complex, shattered chart,
A high-energy testament that tears a world apart.

The sirens wail, the binder’s grip, a fight against the bleed,
A race against the golden hour, to plant a healing seed.
For in this shattered framework lies a story to be told,
Of trauma’s sudden, cruel embrace, in histories of old.

• The artery of the ligamentum teres, a branch of the obturator artery, provides minimal contribution to the femoral head’s blood supply in adults and is insufficient to prevent avascular necrosis if the main supply is compromised.

• While the lateral circumflex femoral artery contributes to the vascularity around the hip, its primary supply is to the femoral neck and trochanteric region, not the weight-bearing dome of the femoral head.

• The femoral head receives its principal blood supply from the deep branch of the medial femoral circumflex artery (MFCA).
• This vessel is particularly vulnerable to disruption during hip dislocation or displaced fractures of the acetabulum and femoral neck, which can lead to avascular necrosis.
• Yoon, T. R., et al., J Bone Joint Surg Br, 2011.

• The obturator artery gives rise to the artery of the ligamentum teres but does not directly supply the femoral head with its main vascularity.

• The integrity of the anterior column is primarily assessed by evaluating the iliopectineal line.

• The ilioischial line, also known as Köhler’s line, represents the radiographic landmark for the posterior column of the acetabulum.
• Disruption of this line on an AP pelvis radiograph indicates a fracture involving the posterior column.
• Judet, R., et al., Radiology, 2025.

• The anterior wall or rim of the acetabulum is best visualized on the iliac oblique Judet view and is represented by its own distinct radiographic contour on the AP view.

• The posterior wall is another distinct landmark on the AP view, typically projecting more laterally than the anterior wall, and is best profiled on the obturator oblique Judet view.

• Intraperitoneal bladder rupture results in urine and contrast extravasating into the peritoneal cavity, outlining bowel loops and filling the paracolic gutters, rather than causing extrinsic compression of the bladder.

• While extraperitoneal rupture involves leakage of urine, the classic teardrop shape is not caused by the urinoma itself but by the compressive mass effect of the associated hematoma.

• Bladder neck avulsion is a severe injury but does not typically produce the symmetrical, elongated teardrop shape; it would more likely result in superior displacement of the bladder base.

• The “teardrop” or “pear-shaped” bladder sign is caused by extrinsic compression from a large, contained pelvic hematoma that elevates and narrows the base of the bladder bilaterally.
• This finding is a classic radiologic sign associated with significant pelvic trauma.
• Prather, G. C., & Kaiser, T. F., J. Urol., 1950.

• The femoral nerve is located anteriorly and is not typically at risk with posterior hip and acetabular injuries.

• The sciatic nerve courses directly posterior to the acetabulum and is highly susceptible to injury with posterior wall fractures and dislocations.
• The common peroneal division is more frequently affected than the tibial division, leading to deficits such as foot drop (weakness of dorsiflexion) and weakness of eversion.
• Fassett, D. R., et al., J Orthop Trauma, 2007.

• The obturator nerve passes through the obturator foramen and is more commonly associated with anterior column fractures.

• Hip adduction is controlled by the obturator nerve, which is not in the typical zone of injury for posterior acetabular trauma.

• The iliac oblique view is used to assess the posterior column and the anterior wall of the acetabulum.

• The obturator oblique view projects the obturator foramen open and provides a clear profile of the anterior column and, most importantly, the posterior wall of the acetabulum, making it the ideal view for assessing posterior wall fractures.
• Durkee, N. J., et al., AJR Am J Roentgenol, 2006.

• While the AP view is essential for an overall assessment of the pelvis and can show evidence of a posterior wall fracture, it does not delineate the fracture pattern as clearly as the oblique views.

• The inlet view is primarily used to evaluate for anteroposterior displacement and rotational deformities of the pelvic ring, not for detailed acetabular wall assessment.

• In an intraperitoneal rupture, contrast extravasates into the peritoneal cavity, where it will be seen outlining loops of bowel and filling the paracolic gutters.

• Extraperitoneal bladder rupture, the most common type of bladder injury in pelvic trauma, is characterized by the extravasation of contrast-laden urine into the extraperitoneal tissues surrounding the bladder, primarily the prevesical space (space of Retzius).
• This can create a “molar tooth” appearance on imaging.
• Morgan, D. E., et al., AJR Am J Roentgenol, 2000.

• A urethral injury would demonstrate contrast extravasation at the level of the urethra, often below the bladder base, and may prevent contrast from filling the bladder altogether.

• Ureteral injury would result in contrast extravasation along the course of the ureter, superior to the bladder, often seen on delayed-phase imaging after intravenous contrast administration.

• The ilioischial line is the radiographic landmark for the posterior column. Its disruption indicates a posterior column fracture.

• Shenton’s line is an arc formed by the inferior border of the superior pubic ramus and the inferomedial border of the femoral neck. Its disruption is indicative of hip dislocation or a femoral neck fracture, not specifically an acetabular column fracture.

• The iliopectineal line extends from the iliac wing down to the pubic tubercle and represents the pelvic brim.
• It is the key radiographic landmark for the anterior column of the acetabulum, and its disruption is a hallmark of fractures involving this column.
• Judet, R., et al., Radiology, 2025.

• The sacral arcuate lines are located on the anterior surface of the sacrum and are assessed for sacral fractures, not acetabular column integrity.