Pelvic Discontinuity Associated With Total Hip Arthroplasty

Evaluation and Management

Matthew P. Abdel, MD; Robert T. Trousdale, MD; Daniel J. Berry, MD

Disclosures

J Am Acad Orthop Surg. 2017;25(5):330-338. 

In This Article

Preoperative Patient Evaluation

Successful management of pelvic discontinuity encountered during revision THA requires preoperative evaluation and planning. This strategy also ensures that the appropriate revision and pelvic stabilization equipment will be available intraoperatively.

History and Physical Examination

A thorough history and physical examination are critical when a pelvic discontinuity is suspected. In the history, all prior procedures should be noted. Obtaining previous surgical reports and implant stickers will help identify the specific devices used and their size. Most patients report pain, particularly with weight bearing. Pain at rest or at night is concerning for a septic etiology and should be further investigated. On examination, the soft-tissue envelope should be evaluated, with emphasis on prior incisions and abductor function. A detailed neurovascular examination should be performed.[10]

Laboratory Analysis

In addition to the physical history and physical examination, serum erythrocyte sedimentation rate and C-reactive protein level should be obtained before revision. When infection is suspected, a preoperative hip aspiration should be completed to assess the cell count with differential and cultures. A synovial fluid white blood cell count >1,700 cells/μL or a neutrophil percentage >65% is highly suggestive of a chronic periprosthetic infection.[11]

Imaging Evaluation

Accurate imaging of the acetabulum is essential in the diagnosis and management of pelvic discontinuity. Plain radiographs are the pillar of an accurate diagnosis. The following radiographs should be obtained for all patients with a suspected pelvic discontinuity: a well-centered AP view of the pelvis, an AP view of the hip, and a cross-table lateral view. In addition, the surgeon may want to obtain 45° oblique Judet radiographs, including iliac oblique and obturator oblique views. A recent investigation highlighted the utility of the Lequesne (false-profile) view in depicting a pelvic discontinuity.[12] Finally, Martin et al[13] recently showed that a combination of a radiographs, including an AP view of the pelvis, a true lateral view of the hip, and a Judet view allowed identification of pelvic discontinuity in a high percentage of patients in a large series.

The following findings on preoperative AP pelvic radiographs have been associated with pelvic discontinuity: visible fracture line, obturator ring asymmetry, and medial migration of the inferior hemipelvis with disruption of the Köhler line[1] (Figures 1 and 2). Evaluation of a true cross-table lateral radiograph is also helpful in patients who have a visible fracture line through the posterior column.[14] Judet views are incrementally helpful in assessing for fractures of the anterior column and posterior wall (ie, on the obturator oblique view) and the anterior wall and posterior column (ie, on the iliac oblique view). Fractures through both the anterior and posterior columns on the Judet views are suggestive of pelvic discontinuity. Wendt et al[12] showed that a false-profile view had a 79% sensitivity for detecting pelvic discontinuity, most likely because the radiograph shows the posterior column en face. Comparison with prior radiographs is often key to diagnosis irrespective of imaging modality.

Figure 2.

AP pelvic radiograph demonstrating obturator ring asymmetry and medial migration of the inferior hemipelvis in a patient with pelvic discontinuity.

CT has been advocated for the diagnosis of pelvic discontinuity. Although CT traditionally has been limited by metal artifact from the arthroplasty, thick cuts, and evaluation in the plane of the discontinuity, recent technological advances have mitigated some of these issues. In particular, modern protocols with metal suppression, thin cuts, and reformatting, along with three-dimensional (3D) reconstructions, have improved detection.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....