[18F]-Fluoride PET/CT Analyses of Postoperative Bone Mineralization Adjacent to Acetabular Cups in Total Hip Arthroplasty: A Randomized Clinical Trial.

Abstract

The longevity of total hip arthroplasty (THA) largely depends on adequate bone formation around the implant. This study used [18F]-fluoride positron emission tomography combined with computed tomography (F-PET/CT) to evaluate skeletal metabolism in the bone surrounding the acetabular cup and to compare the metabolic activity in the periprosthetic regions between cups with 2 different surfaces. Twenty-eight Swedish patients (15 females) with a mean age of 61.3 years were randomly assigned to receive an uncemented cup with either a Trabecular Titanium (TT) surface or a hydroxyapatite (HA) coating. The acetabular bone region surrounding the cup was divided into 9 regions of interest (ROIs). All patients were assessed with use of radiographs and clinical scoring at 36 weeks of follow-up and with use of F-PET/CT at 4, 16, and 36 weeks postoperatively. F-PET/CT scans demonstrated 17% higher levels of metabolic activity indicating osseointegration in the TT group compared with the HA group at 4 weeks postoperatively. Additionally, both groups had higher standardized uptake values (SUVs) compared with the healthy reference acetabulum groups at 4 and 16 weeks postoperatively. A detailed analysis of bone growth on the implant surface revealed that the initial healing phase involves increased mineral accumulation for both TT and HA cups. These findings provide valuable insights into the secondary stabilization of implants, which is critical for prosthesis survival. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.