FIGURE 3-1. Common minor fractures of the pelvis. (A) Anterior superior iliac spine (1), anterior inferior iliac spine (2), ischial tuberosity (3), and iliac wing (4); 1 to 3 are avulsion injuries with muscles labeled. (B) Transverse sacral fracture (5) and isolated pubic rami fractures (6 and 7).

FIGURE 3-2. (A) Anteroposterior (AP) radiograph of the pelvis demonstrating a left ischial tuberosity avulsion fracture (black arrow). (B) Axial T1-weighted magnetic resonance (MR) image of the same patient redemonstrates the fracture (white arrow).

FIGURE 3-3. Anteroposterior (AP) pelvis radiograph demonstrating an isolated comminuted right iliac wing fracture (white arrows).

FIGURE 3-4. Anteroposterior (AP) pelvis radiograph demonstrating minimally displaced left superior and inferior pelvic rami fractures (black arrows) resulting in a single break in the pelvic ring.

FIGURE 3-5. Lateral compression injuries. (A) Type I: force applied posterolaterally (arrow), resulting in a crush injury to the sacrum, ilium, and sacroiliac joint (1) and oblique or horizontal pubic rami fractures (2). (B) Type II: force directed anterolaterally (arrow), resulting in diastasis of the sacroiliac joint (1 and 3) (Type IIA) or iliac wing fracture (Type IIB) plus oblique or horizontal pubic rami fractures (2). (C) Type III: force applied anterolaterally (arrow) with oblique or horizontal pubic rami fractures (2) and involvement of both sacroiliac joints and ligaments (1, 3, and 4) (Type IIIA) or sacroiliac joints and ipsilateral iliac wing fracture (Type IIIB).

FIGURE 3-6. Anteroposterior (AP) compression injuries. (A) Type I AP compression injury with vertical pubic rami fractures. Sacroiliac joints are normal. Note the elevated bladder resulting from a large pelvic hematoma. (B) Type II: wider diastasis of the pubic symphysis or vertical pubic rami fractures with disruption of the anterior sacroiliac ligaments. (C) Type III: wider diastasis of the pubic symphysis or displaced vertical pubic rami fractures with disruption of both the anterior and posterior sacroiliac ligaments. (D) AP compression injury with vertical pubic rami fractures. Sacroiliac joints are normal. Note the elevated bladder resulting from a large pelvic hematoma (Type I). (E) AP pelvis radiograph demonstrating a Type II AP compression injury with diastasis of the pubic symphysis, and widening of the anterior right sacroiliac joint (white arrow).

FIGURE 3-6. (continued)

FIGURE 3-7. Vertical shearing injury. (A) Force is applied vertically (arrow) with vertical pubic rami fractures (3) or step-off at the pubic symphysis and disruption of the anterior and posterior sacroiliac ligaments (1 and 2). (B) Anteroposterior (AP) pelvis radiograph demonstrating widening and step-off of the right sacroiliac joint (white arrow) and vertically displaced left pelvic rami fractures (black arrow). Contrast and catheter in bladder from computed tomography (CT) cystogram to evaluate for bladder injury.

FIGURE 3-8. (A) Judet view of the hip demonstrating a nondisplaced central acetabular fracture (curved arrow). (B) Computed tomography (CT) image demonstrating an uncomplicated central acetabular fracture (arrow).

FIGURE 3-9. (A) Acetabular margins and the anterior (iliopectineal) and posterior (ilioischial) columns. (B, C) Three-dimensional shaded surface displays computed tomography (CT) images of the pelvis with electronic subtraction of the right femur demonstrating the anterior (A) and posterior columns (P). Images are obtained with 45-degree right posterior obliquity (B) and left posterior obliquity (C) like the Judet radiographic views of the pelvis.

FIGURE 3-9. (continued)

FIGURE 3-10. Fracture patterns (AO classification). (A) Type A: A1, posterior wall fracture; A2, posterior column fracture; A3-1, anterior wall fracture; A3-2, anterior column fracture. (B) Type B1-1, transverse fracture; Type B1-2, transverse with posterior wall fracture; Type B2, fracture; Type B3, anterior column with posterior transverse fracture. (C) Type C1, both columns with fracture extending to the iliac crest; Type C2, both columns extending to anterior inferior iliac spine; Type C3, both columns with extension to sacroiliac joint. Types A1, B1-1, B1-2, B-2, and C1 are the most common.

FIGURE 3-11. Complex acetabular fracture. (A) Anteroposterior (AP) pelvis radiograph shows a displaced right transverse acetabular fracture (black arrow), a displaced right posterior wall fracture (white arrow), and left superior and inferior pelvic rami fractures (white arrowhead). (B, C) Three-dimensional shaded surface displays computed tomography (CT) images of the fractures. The right posterior oblique view (B) demonstrates the transverse acetabular fracture (white arrows) and the pelvic rami fractures (black arrows). The posterior view (C) demonstrates the transverse acetabular fracture (white arrow) and the posterior wall fracture (black arrow).

FIGURE 3-11 (continued)

FIGURE 3-12. (A) Left posterior oblique (Judet) radiograph demonstrates posterior dislocation of the right femoral head (black arrow) and a posterior wall acetabular fracture (white arrow). (B) Anteroposterior (AP) pelvic radiograph demonstrates an anterior dislocation of the left femoral head.

FIGURE 3-13. (A) Coronal multiplanar reformat computed tomography (CT) image of a posterior dislocation. Note the posterosuperior position of the femoral head (white arrow), which is typical. (B) Two axial CT images after attempted reduction of the posterior dislocation shown in (A). Multiple intra-articular fragments (black arrows) from the posterior wall fracture (white arrows) are preventing reduction.

FIGURE 3-14. (A) Anteroposterior (AP) right hip radiograph demonstrates an impacted femoral neck fracture (black arrows) with cortical disruption and trabecular compression laterally. (B) Treated by percutaneous pinning.

FIGURE 3-14 (continued)

FIGURE 3-15. (A) Displaced femoral neck fracture (black arrows). (B) Treated with bipolar hemiarthroplasty. Note the prior right femoral neck fracture treated by percutaneous pinning.

FIGURE 3-16. Femoral neck stress fracture. Coronal fast spin-echo, T2-weighted fat-suppressed image demonstrates edema with a central linear low-intensity fracture line (arrow).

FIGURE 3-17. Sites for avulsion fractures in the pelvis and hips with muscle origins labeled.

FIGURE 3-18. Anteroposterior (AP) pelvic radiograph of a comminuted intertrochanteric femur fracture (black arrows) angular deformity (coxa vara deformity).

FIGURE 3-19. Anteroposterior (AP) hip radiograph of a subtrochanteric femur fracture with overriding and marked angulation of the fragments (coxa vara deformity). Soft tissue swelling lateral to the fracture is secondary to a hematoma.

FIGURE 3-20. (A) Anteroposterior (AP) pelvis radiograph demonstrates subtle bone condensation in the left sacral ala (black arrow) caused by a sacral insufficiency fracture. (B) Coronal Short Tau Inversion Recovery (STIR) magnetic resonance (MR) image demonstrates marrow edema at the site of the fracture (white arrows).

FIGURE 3-21. (A) Anteroposterior (AP) pelvis radiograph with subtle bone condensation in the right acetabulum (black arrows) caused by an acetabular insufficiency fracture. (B) Coronal STIR magnetic resonance (MR) image demonstrates a fracture line (white arrows) and adjacent marrow edema.

FIGURE 3-22. Axial (A) and sagittal (B) T2-weighted fat-suppressed images of a Grade 2 strain of the rectus femoris. (A) The muscle edema is centered at the myotendinous junction (white arrow). (B) Feathery edema extends through the muscle fibers (black arrows) with a small anterior hematoma (white arrow).