Pulmonary embolism after hip or knee replacement: postoperative changes on pulmonary scintigrams in asymptomatic patients.

Abstract

Serial pulmonary imaging has proved to be effective in the evaluation of patients undergoing total joint arthroplasty. A clinical dilemma arises in asymptomatic patients whose postoperative pulmonary images differ from the preoperative images. The authors prospectively evaluated 403 patients with serial imaging to determine the significance of changed postoperative images in asymptomatic patients undergoing total hip or knee arthroplasty. Twenty-two (5.5%) patients had significant changes on postoperative images. Seventeen were asymptomatic; all but one underwent pulmonary angiography. Documented pulmonary emboli were demonstrated in 100% of patients whose postoperative images changed to indicate a high probability of pulmonary embolism, 71% whose images changed to a moderate probability, and 0% whose images changed to indeterminate probability. Overall, pulmonary emboli occurred in 76% of all asymptomatic patients with significantly change postoperative images. Asymptomatic pulmonary embolism is a significant occurrence after total hip or knee repair, and a changed lung scan with appropriate clinical evaluation is an accurate indicator of pulmonary emboli in asymptomatic postarthroplasty patients.

Incidence of pulmonary embolism in a chest hospital in Japan and importance of preoperative perfusion lung imaging in the diagnosis of postoperative pulmonary embolism

“…25,26 Our data also show the importance of preoperative perfusion lung images in patients with lung surgery or lung related surgical procedures. A similar risk of developing pulmonary embolism should also be expected in postoperative patients who were operated on other organs.…”

Incidence and natural history of deep-vein thrombosis after total hip arthroplasty

“…[33][34][35] However, these authors also observed that about one in six patients have an abnormal lung scan after total knee or total hip surgery. Therefore, a lung scan may not be a useful screening test.…”

Single-Photon Emission Computed Tomography in the Screening for Postoperative Pulmonary Embolism

“…However, as these studies employed only plannar images, and were based on correlative findings with pulmonary angiography, which has a low sensitivity [7], different or modified approaches that can effectively diagnose PE are needed, especially for patients with elective surgery. The usefulness of preoperative and postoperative lung scintigraphy has been demonstrated in orthopedic surgery [16,17,20,21]. Detection of additional defects postoperatively is a key for the diagnosis of PE, and asymptomatic PE is a common event in postarthroplasty patients.…”

“…All segmental defects were detected postoperatively and comparison with baseline scan was not needed, demonstrating that postoperative SPECT is sufficient for screening postoperative PE in this study setting. In studies using planar images, detection of differences between pre-and postoperative scans was useful because of its low spatial resolution and low specificity [16,17,19]. In contrast, SPECT imaging has a higher specificity [12], allows segmental localization of the perfusion defect, and reveals additional defects not seen on planar scans [13].…”

“…Since several studies have demonstrated the usefulness of serial planar scintigraphy for the screening of postoperative PE by direct comparison of pre-and postoperative images [16,17], we hypothesized that postoperative PE could be diagnosed more precisely with the use of SPECT pre-and postoperatively.…”