Catastrophic Fracture of a Stable Metal Acetabular Component

Abstract

Various modes of failure of primary and revision total hip arthroplasty have been well documented in the literature over the past 30 years. Concerns over polyethylene wear, osteolysis, and hypersensitivity reactions leading to component loosening and early revision have been evaluated and reported in the literature. Routine follow-up is important to monitor for postoperative issues that might lead to the subsequent need for revision.This article describes a case of a 64-year-old man who initially presented 11 years prior with an intertrochanteric fracture, which failed secondary to varus alignment and femoral head osteonecrosis. The fixation was converted to a total hip replacement using the S-ROM system (DePuy, Warsaw, Indiana). Subsequently, the patient was lost to follow-up after primary total hip arthroplasty and presented with a catastrophic fracture of the metal acetabular cup system. The failure was suggested by clinical presentation and confirmed by imaging studies showing a fractured acetabular shell with femoral head prosthesis resting in the superolateral ileum. The contributing factors that resulted in mechanical failure were polyethylene wear and component fracture. The acetabular component was revised with an in-growth cementless trabecular metal multihole cup (Zimmer, Warsaw, Indiana) with bone grafting of acetabular defects.Routine assessments help educate patients and allow careful monitoring by physicians while establishing a radiographic timeline for the identification, progression, or lack of postoperative complications.

Prosthetic femoral head erosion through an acetabular component treated with revision and implant preservation

“…Although femoral head penetration through a cobalt-chrome or titanium acetabular shell is a rare complication, it has been reported in several case reports over the last 25 years. We were able to identify 19 English-language case reports of prosthetic femoral heads penetrating through acetabular liners and at least partially through acetabular shells from 1994 to 2017 in multiple countries including the United States, Greece, the United Kingdom, Taiwan, Italy, and Singapore [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Multiple different implant systems as well as bearing surfaces (including metal-on-metal, ceramic-onpolyethylene, and metal-on-polyethylene) have at least one case report on prosthetic femoral head erosion through the acetabular liner and shell.…”