Editor’s Spotlight/Take 5: CT Pulmonary Angiography After Total Joint Arthroplasty: Overdiagnosis and Iatrogenic Harm?

Abstract

CT pulmonary angiography (CTPA) has become the accepted standard for the evaluation of a patient with suspected pulmonary embolism (PE) [3, 7]. The test is fast, relatively inexpensive, and believed to be even more sensitive (and better overall) than conventional pulmonary angiography with plain radiography — once considered the gold standard for evaluating suspected PE. But in terms of sensitivity, it may be possible to have too much of a good thing. There is some evidence [4] to suggest that in an “all-comers” population of inpatients, the use of CTPA has resulted in overdiagnosis of PE, resulting in complications one would expect from the increased use of anticoagulation. D’Apuzzo and colleagues performed a similar study in total joint arthroplasty patients, and they present their results in CORR® this month. Their results generalize well to the population of orthopaedic inpatients at large. How should physicians work up a patient presenting with nonspecific symptoms that suggest PE (moderate tachycardia or tachypnea, for example), when those same symptoms could just as easily be caused by numerous other postoperative diagnoses? This is not just a problem in arthroplasty or tumor surgery — the answer to this question, when we get it, will benefit all orthopaedic patients. Pulmonary emboli occur after ankle fractures and ACL reconstructions, too. PE can cause sudden death, and deaths from PE are almost always are unexpected. For those reasons, PE is a dreadful and important diagnosis. CTPA identifies clots, but not all the clots it finds cause problems, and the treatment for those clots can cause harm. We still do not know when to order this test, or which CTPA findings deserve our worry (and our interventions). Preliminary work has been performed in orthopaedic populations [7] to try to obtain these answers, but we know much less than we need to know to do a good job for our patients when it comes to PE. In the “Take 5” interview that follows, Dr. James Browne (Fig. 1), lead author on this important study, joins us to explore this critical topic in greater depth. Fig. 1 James A. Browne MD said physicians should balance testing for PE with its treatment risks to ensure that patients are not subjected to unnecessary iatrogenic harm