ePoster #722 - ISHA Annual Scientific Meeting 2016

Advanced Imaging Adds Little Value in the Diagnosis of Symptomatic FAI

Daniel Cunningham, BS, Durham, NC UNITED STATES
Chinmay Paranjape, MHS, Durham, NC UNITED STATES
Shane J. Nho, MD, MS, Chicago, IL UNITED STATES
Joshua David Harris, MD, Houston, TX UNITED STATES
Steven Olson, MD, Durham, NC UNITED STATES
Richard C. Mather, MD, MBA, Durham, NC UNITED STATES

Duke University School of Medicine, Durham, NC, UNITED STATES

FDA Status Not Applicable

Summary: Using current costs and published test characteristics, physical exam with or without hip injection is more cost-effective for diagnosis of symptomatic femoroacetabular impingement than physical exam with advanced imaging.

Background: Symptomatic femoracetabular impingement (FAI) with labral tear is increasingly recognized as a common source of chronic hip pain and disability in young to middle-aged active adults. However, the diagnosis can be difficult, leading to delays in care. Providers often supplement their history and physical exam (H&P) maneuvers with hip injection, magnetic resonance imaging (MRI) or magnetic resonance arthrography (MRA). Since diagnostic imaging represents the fastest rising segment of costs in US healthcare [Medicare Payment Advisory Commission, 2010], there is a need for value driven diagnostic algorithms. Therefore, the purpose of this study was to identify the most cost-effective diagnostic strategy for symptomatic FAI, comparing physical exam alone or physical exam with hip injection, MRI, or MRA.

Methods: A simple-decision model run as a cost-utility analysis (TreeAge Pro 2016) was constructed to assess the diagnostic value added to history and physical examination of the following in the diagnosis of symptomatic FAI: 1) H&P + MRI, 2) H&P + MRA, and 3) H&P + anesthetic injection. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with willingness-to-pay (WTP) set at $100,000/QALY.

Results: In the base case, H&P alone or H&P with hip injection dominated (less costly and more effective) strategies containing advanced diagnostic imaging for detection of clinically symptomatic FAI. Sensitivity analyses revealed that H&P with hip injection was preferred over H&P alone in situations with WTP > $55,000, low physical exam sensitivity, high FAI prevalence and increased time spent in non-operative rehabilitation.

Discussion: H&P alone or H&P with hip injection are preferable to diagnostic strategies that include advanced imaging even with reasonable deviations from published values of disease prevalence, test sensitivity and test specificity. While this study demonstrates it is not cost effective to use MRI or MRA in the routine diagnosis of FAI, it does not necessarily suggest that there is no role for imaging in the management of FAI. There may be a role for advanced imaging in operative planning. One limit of the study inference is the generalizability of physical exam accuracy, which is dependent on the examiner. This further underscores the importance of teaching and maintaining a comprehensive musculoskeletal exam to all healthcare providers as a cost minimization intervention. In a healthcare environment where diagnostic imaging represents the highest growing segment of healthcare costs, the outcomes of this study are exciting as a potential means for reducing costs without sacrificing diagnostic effectiveness.