Reduced-dose computed tomography to detect dorsal screw protrusion after distal radius volar plating Reduced-Dose CT to Detect Radius Screw Protrusion [version 1; peer review: 1 approved]

• Published in: F1000 research Vol. 7
• Main Authors: Leffers, Kevin J., Kosty, John W., Garcia, Glenn M., Jupiter, Daniel C, Lindsey, Ronald W., Gugala, Zbigniew
• Format: Journal Article
• Language: English
• Published: 2018
• Subjects: distal radius fracture; reduced-dose computed tomography; volar plating; radiation exposure
• DOI: 10.12688/f1000research.15056.1

Background: Tenosynovitis and tendon rupture caused by screw penetration of the dorsal cortex are common complications after fixed-angle volar plating of a distal radius fracture. Detecting screw prominence with plain radiography is difficult due to the topography of the distal radius dorsal cortex. Computed tomography (CT) offers more detailed imaging of the bone topography, but is associated with radiation exposure. The present cadaveric study compared reduced-dose and standard-dose CT protocols in the detection of dorsal screw protrusion after fixed-angle volar plating of distal radius fracture. If found equivalent, a reduced-dose protocol could decrease the total radiation exposure to patients. Methods: Standard size distal radius volar locking plates were placed using a standard Henry approach in 3 matched pairs of cadaver wrists. A total of 3 distal locking screws were placed at 3 different lengths for a total of 3 rounds of CT scans per wrist pair. Each wrist pair was imaged by CT using standard-dose and reduced-dose protocols. Dorsal screw penetration was measured in each imaging protocol by 3 radiologists at two time periods to calculate inter- and intra-observer variability. Variability was calculated using the concordance correlation coefficient (CCC), intra-class correlation coefficient (ICC), and Pearson correlation coefficient (PCC). Bland-Altman plots were used and assessed 95% limits of agreement. Results: Intra- and inter-observer variabilities, either with the reduced-dose or standard-dose protocol, were >0.85. Pairwise CCC, ICC, and PCC were >0.91. In the comparison of reduced dose versus standard dose between radiologists, correlations were always >0.95. Conclusions: Comparison of a reduced-dose CT protocol and a standard-dose CT protocol for the detection of dorsal penetrating screws after fixed-angle volar plating showed >0.95 correlation in this cadaveric model. A reduced-dose CT protocol is equivalent to a standard dose CT protocol for orthopedic imaging and should reduce radiation exposure.