Appropriateness of the Use of Magnetic Resonance Imaging in the Diagnosis and Treatment of Wrist Soft Tissue Injury.

BACKGROUND: When diagnosing wrist soft tissue injury, the authors hypothesize that magnetic resonance imaging is used injudiciously and is associated with unnecessary cost.

METHODS: A retrospective review was conducted of patients aged 20 to 60 years who underwent magnetic resonance imaging for possible wrist soft tissue injury at a tertiary care center between 2009 and 2014. Treatment recommendation was classified as nonoperative, operative, or equivocal. If the magnetic resonance imaging-directed treatment recommendation differed from the pre-imaging recommendation, it was noted that the imaging influenced patient care (impact study). The cost estimate of an impact study was calculated by dividing the total studies performed by the number of studies that impacted the treatment recommendation and multiplying this value by the institutional wrist magnetic resonance imaging cost ($2246 in 2016).

RESULTS: One hundred forty patients were included. Magnetic resonance imaging affected treatment recommendation in 28 percent of patients. Independent predictors of impact on treatment recommendation were "question specific injury" (OR, 9.46; 95 percent CI, 3.18 to 28.16; p < 0.001) and "question scapholunate injury" (OR, 2.88; 95 percent CI, 1.21 to 6.88; p = 0.02). The only independent predictor of surgery was ordering physician (hand surgeon) (OR, 3.69; 95 percent CI, 1.34 to 10.13; p = 0.01). The cost of an impact study ordered by a non-hand surgeon versus a hand surgeon was $13,359 versus $6491, respectively.

CONCLUSIONS: The provider must carefully consider the pretest probability of ordering a study that will affect treatment recommendation. Injudicious screening with magnetic resonance imaging ($15,565) incurred a cost nearly seven times the cost of the one imaging scan ($2246) before impacting one treatment recommendation. In the current era of cost containment and bundled payment, diagnostic test probability must be appreciated to guide physician ordering practices.