Entrance skin dose calculation for the mini C-Arm—Establishing a diagnostic reference level for wrist fractures

Abstract

Displaced distal radius fractures are common injuries and present regularly to most orthopaedic surgeons. Several documented treatment modalities for these fractures have been described with a recent trend for internal fixation with volar plating. However, the literature suggests that there is still no consensus as to the best treatment of these injuries. We set out to find the current consensus amongst orthopaedic surgeons in the Northwest and Northeast of England with respect to treatment of displaced distal radius fractures. A questionnaire was sent out to all consultant orthopaedic surgeons practicing in these regions. Antero-posterior and lateral radiographic images of two cases of displaced distal radius fractures (one extraarticular and the other intraarticular) were provided along with a short history. A list of the common modalities of treatment was given. Each surgeon was asked to indicate their ideal method of management of each of these cases. Two hundred and forty-four questionnaires were sent out and a completed form was received from 166 (69%) of surgeons. The results again indicated a wide variety of opinion as to the best way to manage these two cases. The most popular methods of treatment were MUA + Kwiring, volar plating and application of an external fixator. In the extraarticular fracture, 82 (49%) surgeons favoured MUA + K-wiring, 47 (28%) favoured volar plating and 14 (8%) an external fixator. In the intraarticular case, 28 (17%) surgeons favoured MUA + K-wiring, 53 (32%) advocated volar plating and 33 (20%) an external fixator. Upper limb surgeons were more likely to treat these with volar plating (63% in each case) than non upper limb surgeons (18% and 23% for each case). A randomised clinical trial would help elucidate which treatment is best for these common injuries Introduction: The establishment of diagnostic reference levels (DRLs) for all typical radiological examinations became a mandatory requirement following the implementation of the Ionising Radiations Medical Exposure Regulations Act (IRMER) 2000. At present there are no guidelines from the Health Protection Agency (formerly the National Radiation Protection Board) regarding use of fluoroscopy in orthopaedic trauma. The mini C-arm image intensifier allows surgeons to perform fluoroscopy in the out-patient setting in the absence of trained radiographers. Its increasing popularity amongst surgeons has led to concerns regarding use of ionizing radiation by personnel who have not been trained in radiation protection. It is therefore essential to have formal protocols for use of the mini C-arm in order to comply with the law and to maintain safe clinical practice.Objective: To provide data on dosage for wrist fracture manipulations in order to establish a DRL for this procedure.Methods: Screening times were recorded for 80 wrist manipulations in a fracture clinic setting using a mini C-arm image intensifier. The entrance skin doses (ESD) for the procedures were calculated and a diagnostic reference level was set using the third qu...