Acetabular component revision in total hip arthroplasty. Part II: management of major bone loss and pelvic discontinuity.

Use of structural bone graft and/or reconstruction cage devices in acetabular revisions with major bone loss has the advantages of providing a stable construct at the anatomical hip center of rotation and, theoretically, reconstituting bone stock. When the structural graft supports more than 50% of the acetabular component, a reconstruction cage device spanning ilium to ischium should be used to protect the graft and provide structural stability. Recent introduction of trabecular metal cups and augments and custom triflanged acetabular components has increased the potential for biological fixation and long-term stability of revision constructs. Longer follow-up of these reconstructions is needed. Revisions with pelvic discontinuity and major bone loss have a high failure rate and require techniques either to reduce and plate the discontinuity or to distract the discontinuity to achieve long-term stability.