In revision total hip arthroplasty for massive acetabular bone loss, a trabecular metal augment is used to reconstruct the anterior column. According to the American Academy of Orthopaedic Surgeons classification, which defect type requires bulk structural allograft or a custom triflange component rather than particulate augments alone?

• A Type I (segmental, non-contained)
• B Type II (cavitary, contained)
• C Type IV (arthrodesis)
• D Type III (combined cavitary and segmental, pelvic discontinuity) ✓

Explanation

Type III defects, which involve combined cavitary and segmental loss or pelvic discontinuity, cannot be managed with particulate augments alone. They require bulk structural allograft, custom triflange cups, or cup-cage constructs. Cavitary (Type II) defects are amenable to particulate augments or hemispherical components.

Reference: Campbell's Operative Orthopaedics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.