Role of radiographs, CT scan and 3-dimensional high frequency-power Doppler in diagnosing postoperative scaphoid union

Abstract

Radiographs and Computed Tomography (CT) scan in the post-operative period can confirm the scaphoid union. Time delay and inter-observer variability in radiographs, radiation, and stair-step artifacts in CT are considered its disadvantages. 3D High Frequency-Power Doppler Ultrasonography (3D-HFDU) is a simple and well reliable diagnostic modality assesses the blood flow, vascularity of the bone graft, and fracture healing. The role of 3D-HFDU in diagnosing post-operative scaphoid union is evaluated and compared with radiographs and CT scan at different time intervals. 18 patients operated for scaphoid non-unions by 1,2-intercompartmental Supraretinacular artery (1,2 ICSRA) vascularized distal radial grafts between January 2012 and July 2014 were assessed with post-operative radiographs, Multidetector computed tomography scan (MDCT) and 3D-HFDU at 6,12 and 18 weeks interval. Two different blind observers analyzed, and the interpreted the results. Postoperative radiographs and MDCT scan detected partial healing of scaphoid nonunion as early as 6 weeks and subsequently bridging trabeculae, closure of gap and graft incorporation, and complete union at 12 and 18 weeks. 3D-HFDU showed decreased blood flow signal intensity and no signs of fracture healing at 6 weeks. At 12 and 18 weeks, there were good blood flow signals, (doppler spectral analysis) persistent and consistent with vascularized graft, neovascularization, and angiogenesis across the bone graft and surrounding tissues confirming fracture healing. Although CT scan is a preferred modality for diagnosing scaphoid union, 3D-HFDU proved to be a simple, real-time, noninvasive and a well reliable modality in assessing the vascularity of the bone graft and the scaphoid union. IV- Diagnostic.