Abstract
Acetabular fracture treatment outcomes have improved over the past two decades due to the more accurate identification of common fracture patterns, the development of more adequate surgical approaches, and the creation of improved methods for reduction and repair. However, certain cases have a distinctly lower likelihood of a favorable outcome, and in this setting primary arthroplasty as part of the open reduction and internal fixation (ORIF) may provide the best solution. Acute primary total hip arthroplasty (THA) provides primary stability and immediate pain relief, permits graded weight-bearing and early pain-free mobilization, and may also treat pre-existing hip arthritis. Removal of the femoral head improves exposure making fracture reduction and fixation easier without the need for more extensile approaches. Open reduction and internal fixation to obtain stability of the anterior and posterior columns is followed by placement of a multi-holed acetabular shell which serves as a supplementary internal fixation device. The femoral head can be used as bulk bone graft to replace and reinforce the reconstruction. These complex procedures are best undertaken by a surgical team with substantial experience with both acetabular trauma and hip arthroplasty.
Despite improvements in outcomes with ORIF, THA is commonly required following failed treatment. Scarring, heterotopic ossification, bone defects, residual deformity, devitalised bone fragments and previous implants can make the procedure challenging. If the patient has undergone previous ORIF it is important to rule out low grade sepsis with appropriate blood tests (ESR + CRP) and further work-up as warranted. Surgical exposure must be carefully planned so as to be able to access all aspects of the acetabulum, including removal of hardware which may interfere with acetabular component placement.
Bone stock loss, malunion and/or non-union must be evaluated with appropriate radiographs or CT scans may be required. Acetabular replacement in the face of deformity from previous trauma encompasses three main problems; bony defects, the presence of bone in places where it is not normally encountered, such as surrounding and incarcerating the femoral head, or substantially anterior or lateral to the center of the acetabulum, and movement of the acetabulum from its normal relationship to the remainder of the pelvis to a new location, such as a higher or more medialised hip center. Intraoperative landmarks may be obscured and therefore placement of reamers and the component may be confusing. THA after acetabular fracture is technically demanding and generally is accompanied by results more typical of revision than primary arthroplasty for degenerative disease.
