Pseudotumor Treated with Two-Stage Revision Due to Aggressive Osteolysis and Soft-Tissue Mass Following Metal on Metal Total Hip Arthroplasty

A 71-year-old male with BMI of 27.7 and history of a left MoMTHA in 1999 presented to our institution with 8 years of chronic, progressive left groinand thigh pain which was worse with weight-bearing and at night. He had complete loss of hip and knee range of motion and required a walker for ambulation. Surgical history includes left acetabular liner and femoral head exchange, without relief of symptoms, 3 years prior to presentation. Radiographs showed extensive osteolysis surrounding the acetabular implant with posterolateral subluxation of the femoral head, as well as severe osteolysis involving the femoral shaft with multiple large