Open Reduction and Internal Fixation of Posterior Wall Acetabular Fractures



Open Reduction and Internal Fixation of Posterior Wall Acetabular Fractures


Lawrence X. Webb, MD, MBA


Dr. Webb or an immediate family member is a member of a speakers’ bureau or has made paid presentations on behalf of the Musculoskeletal Transplant Foundation; serves as a paid consultant to or is an employee of Biocomposites; has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research-related funding (such as paid travel) from Kinetic Concepts, Doctors Group, Smith & Nephew, Stryker, and Synthes; and serves as a board member, owner, officer, or committee member of the Orthopaedic Trauma Association Southeastern Fracture Consortium Foundation.



INTRODUCTION


Classification

Fractures of the acetabulum are classified according to Letournel into two main groups: elementary fractures and associated fractures.1 The classification is morphologic and is based on Judet oblique view radiographs.2 Each group has five types (Figure 1). Posterior wall fractures are one of the elementary types; they also may occur as a component in two of the associated types—posterior column and posterior wall fractures, and transverse and posterior wall fractures. This chapter focuses on elementary posterior wall fractures. These are the most common of the 10 types, accounting for approximately one-fourth to one-third of all acetabular fractures.3,4


Associated Injuries

Although posterior wall fractures are occasionally seen in isolation, these fractures are often the result of high-energy trauma, and associated injuries are not uncommon. Some of these are life-threatening and should be identified and managed at the time of presentation, using ATLS (Advanced Trauma Life Support) protocols.5

image VIDEO 71.1 Posterior Wall Fracture-Dislocation: Reduction and Traction Pin Placement. Lawrence X. Webb, MD; John M. Tabit, DO (4 min)


The mechanism of injury is thought to be axial loading of the femur with the hip in the flexed position.4 This occurs in motor vehicle accidents with frontal impact when the knee strikes the dashboard. The force is driven via the flexed hip against the posterior wall of the acetabulum, producing the fracture. The size of the fragment is thought to be determined by the degree of abduction or adduction at the time of impact.4 With displacement of the fractured posterior wall, the femoral head is unconstrained, and it subluxates or dislocates posteriorly in 78% to 86% of the cases.4,6 Also, as the femoral head displaces posteriorly, it may impact the edge of the fractured acetabular articular surface, resulting in a marginal impaction fracture. This accompanying fracture occurs in 27% to 46% of posterior wall fractures.4,6 Other potential associated injuries include fracture of the femoral head, femoral neck, and femoral shaft as well as ligamentous injury to the knee.


PREOPERATIVE IMAGING

In patients who present with multiple injuries, careful scrutiny of the initial pelvic radiograph will usually show the fracture. The fracture can be clearly seen and classified on Judet oblique views, particularly the obturator oblique view. CT helps in assessing the femoral head, the size and extent of segmentation or comminution of the posterior wall fragment(s), the size and location of intra-articular fragments, and associated marginal impaction fractures (Figure 2).


Feb 2, 2020 | Posted by in ORTHOPEDIC | Comments Off on Open Reduction and Internal Fixation of Posterior Wall Acetabular Fractures
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