Typical dose values for intra-operative fluoroscopy during orthopaedic trauma surgery at Larnaca general hospital in cyprus: A five-year retrospective study

Abstract

The purpose of this study was to establish typical dose values at orthopaedic operating rooms of the Larnaca General Hospital (LGH). Kerma area product (KAP), fluoroscopy time (FT) and cumulative air-kerma (K_a,r) measurements were collected for 821 patients who underwent common and reproducible trauma surgery over a five-year period, with three mobile C-arm systems; two equipped with an image-intensifier and one with a flat-panel detector. Dose indices were automatically extracted from radiation dose structured reports or DICOM meta-data files archived in the PACS, using custom-made software. The procedures were categorised based on the anatomical area and included foot/ankle, tibia/fibula, knee (distal femur, tibia plateau), femur/trochanter, hip, hand, radius/ulna, elbow, and humerus. The medians of KAP, FT and K_a,r were defined as typical dose values. Variations in dose values among the C-arm systems or different surgical operations involving femur/hip, tibia/fibula, and humerus were analysed as secondary outcomes. For the procedures on upper extremities, the typical dose values ranged between 20.1-197 mGycm² for KAP, 4.50-14.5 s for FT and 0.07-0.71 mGy for K_a,r, whilst for the procedures on lower extremities ranged between 46.6-202 mGycm² for KAP, 4.86-24.0 s for FT and 0.16-0.74 mGy for K_a,r. The largest values were reported for dynamic hip screw (889 mGycm², 14.3 s, 3.10 mGy), and femur/trochanter intramedullary (long/short nail: 2007/1326 mGycm², 52.3/36.0 s, 6.53/4.05 mGy) nailing, respectively. A decrease of up to 65 %, and 74 % was found in median KAP, and K_a,r, and an increase of up to 119 % (except knee's) in median FT values for the procedures performed with the flat-panel systems. Additionally, when comparing surgical operations, only femur/trochanter long/short and tibia intramedullary nailing demonstrated a significant increase in median KAP, FT and K_a,r values compared to dynamic hip screw and fixation with a locking plate, respectively. The typical dose values reported could be used as a guide to appropriate levels of intra-operative fluoroscopy in orthopaedic trauma surgery at LGH, and to encourage further optimisation by providing a baseline for audit of local practice in the absence of national reference doses. These values could also contribute to the establishment of the first national DRLs for orthopaedic trauma surgery.

Keywords: Fluoroscopy; Fluoroscopy time; Kerma area product; Orthopaedic trauma; Radiation; Typical dose values.