Incidental Findings in Low-Dose Full-Body Imaging Taken for Total Hip and Knee Arthroplasty

Abstract

Detection of incidental findings (IFs) in preoperative imaging for total joint arthroplasty (TJA) patients may lead to additional testing, cost, and surgical delay. The purpose of this study is to identify the incidence and clinical significance of IFs on preoperative low-dose full-body imaging (LFI) in the total joint population. Furthermore, we aim to determine whether these findings lead to additional imaging, delay, or cancelation in TJA cases. A retrospective review of 2,183 patients planned for total hip arthroplasty or total knee arthroplasty, who had preoperative LFI imaging obtained from 2013 to 2020 was conducted. LFI radiographic reports were reviewed to identify any flagged radiographs. Flagged IFs were divided into thoracic, spinal, lower limb, and abdominal IFs. Charts were reviewed to identify if any additional imaging was completed, the case was delayed or canceled, or a new pathology requiring continued follow-up or treatment was discovered. Of the 2,183 LFI images taken prior to TJA, 41 cases qualified as having IF (1.9%, 41/2,183), 18 thoracic, 11 spinal, 11 lower limb, and 1 abdominal. Overall, 15 (0.7%, 15/2,183) IF cases were clinically determined to require at least one additional form of imaging. Two had a significant finding; a schwannoma near the distal femoral shaft and a squamous cell carcinoma of the lung. Three TJA cases were delayed, and no cases were cancelled due to the IFs. The possible increase in IF detection by preoperative LFI does not greatly impact TJA case completion. Though rare, providers should pay close attention as clinically significant IFs can be discovered and lead to early treatment. This was a retrospective cohort study with level III evidence.