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

Results

Hemispheric Acetabular Component and Open Reduction and Internal Fixation With Plating

Hemispheric acetabular components with plating are most successful in patients with modest bone loss and large bony surfaces that can be compressed to achieve union. In these patients, noncemented hemispheric cups can be placed, allowing bony ingrowth. Stiehl et al[17] reported healing in 8 of 10 pelvic discontinuities managed with plating of the anterior and posterior columns, bone defect filling with structural allograft, and cemented cups (Table 1). However, the rate of severe complications requiring revision was high. Berry et al[1] reported that five of eight hips with a noncemented socket and posterior plating had a mechanically stable construct at most recent follow-up, with satisfactory results in 50%. In the acute setting, Rogers et al[22] found that none of the eight patients treated with compression plating of the posterior column and an acetabular shell required revision at a mean follow-up of 2.8 years. Moreover, Eggli et al[23] reported on seven patients with plating of both columns. At a mean 8-year follow-up, all acetabular components were stable and the pelvic discontinuities had healed. However, a reinforcement cage was implanted and bone grafting was used in each patient.

Cup-cage Constructs

Cup-cage reconstructions are most commonly used in patients with notable bone loss. Kosashvili et al[24] used an anti-protrusio cage with a highly porous cup and noted no clinical or radiographic loosening in 23 of 26 hips (88.5%) at a mean follow-up of 3.7 years. In the largest series to date, Rogers et al[22] evaluated 62 patients with chronic pelvic discontinuity, with a mean follow-up of 2.9 years. In this series, only 4 of 42 cup-cage reconstructions failed, compared with 6 of 20 reconstructions in which an anti-protrusio cage alone was used (9.5% and 30% failure rates, respectively). Amenabar et al[25] published midterm results on cup-cage constructs used in 45 patients (mean follow-up, 6.4 years). At the most recent follow-up, 4 of 45 cup-cage constructs had been revised for any cause (9% failure rate).

Distraction Method

The distraction method was introduced relatively recently; consequently, data on this method are limited. In their original description of 20 patients treated with the technique, Sporer et al[21] found that 15 patients had radiographic cup stability at a mean follow-up of 4.5 years (Table 1). Although one patient required re-revision for aseptic loosening, "four patients had early migration of their acetabular component but thereafter remained clinically asymptomatic and radiographically stable." In addition, there was considerable improvement in the Merle d'Aubigné and Postel scale score and no postoperative dislocations. Additional series with longer term follow-up are needed to evaluate this reconstruction technique.

Custom Triflange Implants

DeBoer et al[3] and Taunton et al[5] showed that customized triflange constructs for pelvic discontinuity had good midterm results with respect to healing and rates of loosening (Table 1). DeBoer et al[3] reported a healing rate of 90% with this construct at a mean follow-up of 10 years. As expected in a patient cohort with multiple revisions, complications were increased, including a 25% dislocation rate. In a study of data collected from four institutions, Taunton et al[5] reported that 81% of pelvic discontinuities managed with a stable triflange acetabular component had healed at a mean follow-up of 5.4 years. Longer term results with regard to bone stress shielding and pelvic stability are required to more thoroughly evaluate this technique.

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