Aims. The use of fluoroscopy in orthopaedic surgery creates risk of radiation exposure to surgeons. Appropriate personal protective equipment (PPE) can help mitigate this. The primary aim of this study was to assess if current radiation protection in orthopaedic trauma is safe. The secondary aims were to describe normative data of radiation exposure during common orthopaedic procedures, evaluate ways to improve any deficits in protection, and validate the use of electronic personal dosimeters (EPDs) in assessing radiation dose in orthopaedic surgery. Methods. Radiation exposure to surgeons during common orthopaedic trauma operations was prospectively assessed using EPDs and thermoluminescent dosimeters (TLDs). Normative data for each operation type were calculated and compared to recommended guidelines. Results. Current PPE appears to mitigate more than 90% of ionizing radiation in orthopaedic fluoroscopic procedures. There is a higher exposure to the inner thigh during seated procedures. EPDs provided results for individual procedures. Conclusion. PPE currently used by surgeons in orthopaedic trauma theatre adequately reduces radiation exposure to below recommended levels. Normative data per trauma case show specific anatomical areas of higher exposure, which may benefit from enhanced radiation protection. EPDs can be used to assess real-time radiation exposure in orthopaedic surgery. There may be a role in future medical wearables for orthopaedic surgeons. Cite this article: Bone Jt Open 2022;3(11):907–912

Aims. To benchmark the radiation dose to patients during the course of treatment for a spinal deformity. Methods. Our radiation dose database identified 25,745 exposures of 6,017 children (under 18 years of age) and adults treated for a spinal deformity between 1 January 2008 and 31 December 2016. Patients were divided into surgical (974 patients) and non-surgical (5,043 patients) cohorts. We documented the number and doses of ionizing radiation imaging events (radiographs, CT scans, or intraoperative fluoroscopy) for each patient. All the doses for plain radiographs, CT scans, and intraoperative fluoroscopy were combined into a single effective dose by a medical physicist (milliSivert (mSv)). Results. There were more ionizing radiation-based imaging events and higher radiation dose exposures in the surgical group than in the non-surgical group (p < 0.001). The difference in effective dose for children between the surgical and non-surgical groups was statistically significant, the surgical group being significantly higher (p < 0.001). This led to a higher estimated risk of cancer induction for the surgical group (1:222 surgical vs 1:1,418 non-surgical). However, the dose difference for adults was not statistically different between the surgical and non-surgical groups. In all cases the effective dose received by all cohorts was significantly higher than that from exposure to natural background radiation. Conclusion. The treatment of spinal deformity is radiation-heavy. The dose exposure is several times higher when surgical treatment is undertaken. Clinicians should be aware of this and review their practices in order to reduce the radiation dose where possible. Cite this article: Bone Joint J 2021;103-B(4):1–7

Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain. A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated. The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p<0.005). Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations

Introduction. The vast majority of orthopaedic surgeons use C-arm fluoroscopy in the operating theatre when building a circular external fixator. In the absence of previous research in this area, we hypothesised that the surgeon who builds a circular external fixator is exposed to a greater amount of radiation purely as a result of the presence of the metallic fixator in the x-ray beam. The aim of our study therefore was to investigate how the presence of a circular external fixator affects the radiation dose to the surgeon and the surgical assistant. Materials & Methods. A simulated environment was created using a radiolucent operating table, an acrylic lower limb phantom (below knee segment), various configurations of metalic circular external fixation, and a standard size C-arm image intensifier. The variables investigated were 1. the amount of metal in the beam 2. the orientation of the beam (PA vertical vs lateral) 3. the horizonal distance of the person from the beam (surgeon vs assistant) and 4. the vertical distance of the various body parts from the beam (e.g. thyroid, groin). In terms of radiation dose, we recorded two things : 1. the dose produced by the image intensifier 2. the dose rate at standardised positions in the operating theatre. The latter was done using a solid-state survey sensor. These positions represented both where the surgeon and surgical assistant typically stand plus the heights of their various body regions relative to the operating table. Results. The effect of the presence of the circular external fixator : all frame constructs tested resulted in a statistically significant greater radiation dose both produced by the image intensifier and received by the surgical team. The effect of the beam orientation : the PA (vertical) orientation resulted in a statistically significant greater radiation dose for the surgeon than did the lateral orientation, but made no difference for the assistant. The effect of horizontal distance from the beam : unsurprisingly, the surgeon (who was closer to the beam) received a statistically significant greater radiation dose than the assistant. The effect of vertical distance from the beam : for the surgeon, the dose received was highest at the level of the phantom leg / frame, whilst for the assistant there was no statistically significant difference for any level. Conclusions. To our knowledge, this is the first study investigating the radiation dose rate to the orthopaedic surgeon when building a circular external fixator. We found that the surgeon does indeed receive a ‘double whammy’ because the image intensifier puts out a greater amount of radiation plus the metalic frame scatters more of the x-ray beam. Whilst the amounts are relatively small, we think that it's important to quantify doses that orthopaedic surgeons receive to ensure optimal radiation practices

Advances in orthopaedic surgery have led to minimally invasive techniques to decrease patient morbidity by minimizing surgical exposure, but also limits direct visualization. This has led to the increased use of intraoperative fluoroscopy for fracture management. Unfortunately, these procedures require the operating surgeon to stay in close proximity to the patient, thus being exposed to radiation scatter. The current National Council on Radiation Protection recommends no more than 50 mSv of radiation exposure to avoid ill-effects. Risks associated with radiation exposure include cataracts, skin, breast and thyroid cancer, and leukemia. Despite radiation protection measures, there is overwhelming evidence of radiation-related diseases in orthopaedic surgeons. The risk of developing cancer (e.g. thyroid carcinoma and breast cancer) is approximately eight times higher than in unexposed workers. Despite this knowledge, there is a paucity of evidence on radiation exposure in orthopaedic surgery residents, therefore the goal of this study is to quantify radiation exposure in orthopaedic surgery residents. We hypothesize that orthopaedic surgery residents are exposed to a significant amount of radiation throughout their training. We specifically aim to: 1) quantify the amount of radiation exposure throughout a Canadian orthopaedic residency training program and 2) determine the variability in resident radiation exposure by rotation assignment and year of training. This ongoing prospective cohort study includes all local orthopaedic surgery residents who meet eligibility criteria. Inclusion criteria: 1) adult residents in an orthopaedic surgery residency program. Exclusion criteria: 1) female residents who are pregnant, and 2) residents in a non-surgical year (i.e. leave of absence, research, Masters/PhD). After completion of informed consent, each eligible resident will wear a dosimeter to measure radiation exposure in a standardized fashion. Dosimeters will be worn on standardized lanyards underneath lead protection in their left chest pocket during all surgeries that require radiation protection. Control dosimeters will be worn on the outside of each resident's scrub cap for comparison. Dosimeter readings will then be reported on a monthly and rotational basis. All data will be collected on a pre-developed case report form. All data will be de-identified and stored on a secure electronic database (REDCap). In addition to monthly and rotational dosimeter readings, residents will also report sex, height, level of training, parental status, and age for secondary subgroup analyses. Residents will also report if they have personalized lead or other protective equipment, including lead glasses. Resident compliance with dosimeter use will be measured by self report of >80% use on operative days. Interim analysis will be performed at the 6-month time point and data collection will conclude at the 1 year time point. Data collection began in July 2018 and interim 6-month results will be available for presentation at the CORA annual meeting in June 2019. This is the first prospective study quantifying radiation exposure in Canadian orthopaedic residents and the results will provide valuable information for all Canadian orthopaedic training programs

Introduction and Objective. When using radiation intraoperatively, a surgeon should aim to maintain the dose as low as reasonably achievable to obtain the diagnostic or therapeutic goal. The UK Health Protection Agency reported mean radiation dose-area-product (DAP) of 4 Gy cm2 for hip procedures. We aimed to investigate factors associated with increased radiation exposure in fixation of proximal femur fractures. Materials and Methods. We assessed 369 neck of femur fractures between April 2019 and April 2020 in one district general hospital. Fractures were classified as extracapsular or intracapsular and into subtypes as per AO classification. Data was collected on type of fractures, implants used, level of surgeon, duration of surgery and DAP. Types of fractures were subclassified as complex (multifragmentary, subtrochanteric and reverse oblique) or simple. Results. Patients with fractures fixed with DHS, short PFNA, long PFNA and cannulated screws were included. 50% of our patients were fixed with hemiarthroplasty or total hip replacement and were therefore excluded. 184 patients were included in the analysis. There was a significant association of higher DAP with fracture subtype (P=0.001), fracture complexity (P<0.001), if an additional implant was used (P=0.001), if fixation was satisfactory (P=0.002) and the operative time (P<0.001). DAP was higher in PFNA than DHS and greatest in Long PFNA. There was some evidence of association between the level of the surgeon and DAP, although this was not statistically significant (P=0.069) and remained not significant after adjusting for the variables (fracture complexity, fixation or implant used) (p=0.32). Conclusions. Increased radiation in proximal femur fractures is seen in fixation of complex fractures, certain subtypes, the type of implant used and if an additional implant was required. Seniority of surgeon did not result in less radiation exposure even when adjusting for other factors, which is in contrast to other published studies

Background. The advent of EOS imaging has offered clinicians the opportunity to image the whole skeleton in the anatomical standing position with a smaller radiation dose than standard spine roentgenograms. It is known as the fifth modality of imaging. Current NICE guidelines do not recommend EOS scans over x-rays citing: “The evidence indicated insufficient patient benefit in terms of radiation dose reduction and increased throughput to justify its cost”. Methods. We retrospectively reviewed 103 adult and 103 paediatric EOS scans of standing whole spines including shoulders and pelvis for those undergoing investigation for spinal deformity in a tertiary spinal centre in the UK. We matched this against a retrospective control group of 103 adults and 103 children who underwent traditional roentgenograms whole spine imaging at the same centre during the same timeframe. We aimed to compare the average radiation dose of AP and lateral images between the two modalities. We utilised a validated lifetime risk of cancer calculator (. www.xrayrisk.com. ) to estimate the additional mean risk per study. Results. In the Adult EOS Group (AEG) the mean estimated effective dose of AP was 0.08 mSv (0.04–0.15) and Lateral 0.06 mSv (0.03–0.14). Conversely in the Adult Roentgenograms Group (ARG) the mean AP was 0.49 mSv (0.15–1.88) and Lateral was 0.29 mSv (0.07–1.20). In the Paediatric EOS Group (PEG): the mean dose of AP was 0.07 mSv (0.02–0.21) and Lateral 0.04 mSv (0.02–0.11). Conversely Paediatric Roentgenograms Group (PRG) had a mean dose in AP of 0.37 mSv (0.03–5.92) and in lateral of 0.17 mSv (0.03–0.44). The percentage differences were: ARG:AES AP 613%, ARG:AES Lat 483%, PPG:PEG AP 529%, PRG:PEG Lat 425%. Mean difference 513%. The additional lifetime cancer risk for AEG was 1 in 176056 for males and 1 in 138696 for females, compared to ARG 1 in 31596 for males and 1 in 24894 for females. In PEG that was 1 in 58207 for boys and 1 in 33367 for girls, compared to PRG 1 in 11860 for boys and 1 in 6797 in girls. Differences in additional lifetime risk of cancer per scan: ARG:AES Male 557%, Female 557%, PRG:PEG Male 491%, Females 491%. Conclusion. Standard plain film imaging of the whole spine requires approximately five-times higher doses of radiation compared to dual planar EOS scans. This carries a significant impact when considering the need for repeat imaging on additional lifetime malignancy risk in both children and adults. There is approximately 5-fold increase in risk of cancer for all groups with roentgenograms over EOS. We directly challenge the NICE guidance and recommend EOS dual planar imaging in favour of plane roentgenograms for investigation of spinal deformity

Aims. The aim of this study was to quantify the risk of developing cancer from the exposure to radiation associated with surgery to correct limb deformities in children. Patients and Methods. A total of 35 children were studied. There were 19 girls and 16 boys. Their mean age was 11.9 years (2 to 18) at the time of surgery. Details of the radiological examinations were recorded during gradual correction using a Taylor Spatial Frame. The dose area product for each radiograph was obtained from the Computerised Radiology Information System database. The effective dose in millisieverts (mSv) was calculated using conversion coefficients for the anatomical area. The lifetime risk of developing cancer was calculated using government-approved Health Protection Agency reports, accounting for the age and gender of the child. Results. Correction was undertaken in five femurs, 18 tibiae, and 12 feet. The median duration of treatment was 45 months (11 to 118). The mean effective dose was 0.31 mSv (0.05 to 0.64) for the femur, 0.29 mSv (0.01 to 0.97) for the tibia, and 0.027 mSv (0.001 to 0.161) for the foot. The cumulative exposure gave ‘negligible’ risk in 26 children and ‘minimal’ risk in nine children, according to Public Health England categories. These results are below the mean annual background radiation in the United Kingdom. Conclusion. The lifetime attributable risk of developing cancer from repeated exposure to radiation was negligible or minimal in all children. This is the first study to quantify the exposure to radiation from serial radiographs in children with limb deformities who are treated surgically using circular external fixation, linking this to the risk of developing cancer. Cite this article: Bone Joint J 2019;101-B:241–245

Introduction. Patients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study was to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, non-tantalum, porous acetabular components in the setting of prior pelvic radiation. Methods. We retrospectively reviewed 33 patients (38 hips) with prior therapeutic pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (Depuy-Synthes) in 76%, followed by Trident (Stryker) in 8%, Tritanium (Stryker) in 8%, Trilogy (Zimmer-Biomet) in 5%, and G7 (Zimmer-Biomet) in 3%. Eighty-seven percent of cups were fixed with screws, of which the mean number used was 3. The mean age at primary THA was 74 years, 76% were male, and the mean BMI was 30 kg/m. 2. Mean follow-up was 5 years. Results. The 10-year survivorship free of revision for aseptic loosening, free of any revision, and free of any reoperation were 100%, 89%, and 89%, respectively. There were three revisions; one each for taper corrosion, recurrent dislocation, and infection. Radiographically, all cups had evidence of osteointegration and none had radiographic evidence of loosening. The mean Harris hip score improved from 50 to 84 postoperatively (p<0.0001). Conclusion. Contemporary non-tantalum porous acetabular components with supplemental screws provided excellent implant fixation in patients with prior therapeutic pelvic radiation. At 10 years, 100% of these components were free of revision for aseptic loosening and 100% were radiographically well-fixed. Summary. Contemporary non-tantalum porous uncemented acetabular cups provided 100% survivorship free from revision for aseptic loosening for patients undergoing THA following therapeutic pelvic radiation

Radiological imaging is necessary in a wide variety of trauma and elective orthopaedic operations. The evolving orthopaedic workforce includes an increasing number of pregnant workers. Current legislation in the United Kingdom, Europe and United States allows them to choose their degree of participation, if any, with fluoroscopic procedures. For those who wish to engage in radiation-prone procedures, specific regulations apply to limit the radiation dose to the pregnant worker and unborn child. This paper considers those aspects of radiation protection, the potential effects of exposure to radiation in pregnancy and the dose of radiation from common orthopaedic procedures, which are important for safe clinical practice

Background. Radiation exposure remains a significant occupational hazard for Orthopaedic surgeons. There are no references values for trauma procedures performed with Image Intensifier (II). We aimed to determine and compare reference values for patient radiation exposure for common trauma operations, and to analyse the effect of surgeon grade on II usage. Methods. Data collected prospectively from 849 cases between 01/05/2013 and 01/10/2014 were analysed. Statistical analysis was performed to calculate reference values for dose area product (DAP), screening time (ST), and number of II images taken for common trauma procedures where n>9 (n=808). Results. Dynamic hip screw (DHS) fixation required significantly less radiation than proximal femoral nail (PFN) for intertrochanteric hip fractures for median DAP (668mG/cm2 vs 1040mG/cm2, p<0.001), ST (00:36 vs 00:48, p<0.001), and number of II images (65 vs 110, p<0.001). Radiation exposure was statistically significantly less when Consultant Orthopaedic surgeons were first surgeon compared to Staff grade doctors and Orthopaedic trainees for DAP (90.55mGy/cm2 vs 175.5mGy/cm2 vs 366.5mGy/cm2), screening time (00:26 vs 00:32 vs 00:36), and number of II images (49 vs 59 vs 66). Conclusions. We reported reference values for common trauma operations that are essential to enable monitoring of patient radiation exposure. PFN required greater radiation exposure than DHS for intertrochanteric hip fracture. Increased surgical experience lead to lower radiation exposure in trauma operations, which could be developed to assess trauma competence within surgical training. Level of evidence. III

We carried out a prospective study over a period of 12 months to measure the exposure to radiation of the hands of a dedicated foot and ankle surgeon. A thermoluminescent dosimeter ring (TLD) was used to measure the cumulative dose of radiation. Fluoroscopy was used in operations on the foot and ankle. The total screening time was 3028 s, with a mean time per procedure of 37.4 s (0.6 to 197). This correlated positively with the number of procedures performed (r = 0.92, p < 0.001), and with the dose of radiation in both the left (r = 0.85, p = 0.0005) and right TLDs (r = 0.59, p = 0.419). There was no significant difference in the dose of radiation between the two hands (t-test, p = 0.62). The total dose to the right TLD over the 12 months was 2.4 millisieverts. This is a simple and convenient method for evaluating the exposure of a single surgeon to radiation. The radiation detected was well below the annual dose limit set by the International Commission on Radiological Protection

Aims. Minimally invasive transforaminal lumbar interbody fusion (MITLIF) has been well validated in overweight and obese patients who are consequently subject to a higher radiation exposure. This prospective multicentre study aimed to investigate the efficacy of a novel lumbar localisation system for MITLIF in overweight patients. Patients and Methods. The initial study group consisted of 175 patients. After excluding 49 patients for various reasons, 126 patients were divided into two groups. Those in Group A were treated using the localisation system while those in Group B were treated by conventional means. The primary outcomes were the effective radiation dosage to the surgeon and the exposure time. Results. There were 62 patients in Group A and 64 in Group B. The mean effective dosage was 0.0217 mSv (standard deviation (. sd. ) 0.0079) in Group A and 0.0383 mSv (. sd. 0.0104) in Group B (p <  0.001). The mean fluoroscopy exposure time was 26.42 seconds (. sd. 5.91) in Group A and 40.67 seconds (. sd. 8.18) in Group B (p < 0.001). The operating time was 175.56 minutes (. sd. 32.23) and 206.08 minutes (. sd. 30.15) (p < 0.001), respectively. The mean pre-operative localisation time was 4.73 minutes (. sd. 0.84) in Group A and 7.03 minutes (. sd. 1.51) in Group B (p < 0.001). The mean screw placement time was 47.37 minutes (. sd. 10.43) in Group A and 67.86 minutes (. sd. 14.15) in Group B (p < 0.001). The pedicle screw violation rate was 0.35% (one out of 283) in Group A and 2.79% (eight out of 287) in Group B (p = 0.020). Conclusion. The study shows that the localisation system can effectively reduce radiation exposure, exposure time, operating time, pre-operative localisation time, and screw placement time in overweight patients undergoing MITLIF. Cite this article: Bone Joint J 2017;99-B:944–50

Objectives. Computed tomography (CT) plays an important role in evaluating wear and periacetabular osteolysis (PAO) in total hip replacements. One concern with CT is the high radiation exposure since standard pelvic CT provides approximately 3.5 millisieverts (mSv) of radiation exposure, whereas a planar radiographic examination with three projections totals approximately 0.5 mSv. The objective of this study was to evaluate the lowest acceptable radiation dose for dual-energy CT (DECT) images when measuring wear and periacetabular osteolysis in uncemented metal components. Materials and Methods. A porcine pelvis with bilateral uncemented hip prostheses and with known linear wear and acetabular bone defects was examined in a third-generation multidetector DECT scanner. The examinations were performed with four different radiation levels both with and without iterative reconstruction techniques. From the high and low peak kilo voltage acquisitions, polychrmoatic images were created together with virtual monochromatic images of energies 100 kiloelectron volts (keV) and 150 keV. Results. We could assess wear and PAO while substantially lowering the effective radiation dose to 0.7 mSv for a total pelvic view with an accuracy of around 0.5 mm for linear wear and 2 mm to 3 mm for PAO. Conclusion. CT for detection of prosthetic wear and PAO could be used with clinically acceptable accuracy at a radiation exposure level equal to plain radiographic exposures. Cite this article: B. Sandgren, M. Skorpil, P. Nowik, H. Olivecrona, J. Crafoord, L. Weidenhielm, A. Persson. Assessment of wear and periacetabular osteolysis using dual energy computed tomography on a pig cadaver to identify the lowest acceptable radiation dose. Bone Joint Res 2016;5:307–313. DOI: 10.1302/2046-3758.57.2000566

The ankle radiograph is a commonly requested investigation as the ankle joint is commonly injured. Each radiograph exposes 0.01 mSv of radiation to the patient that is equivalent to 1.5 days of natural background radiation [1]. The aim of the clinical audit was to use the Ottawa Ankle Rule to attempt to reduce the number of ankle radiographs taken in patients with acute ankle injuries and hence reduce the dose of ionising radiation the patient receives. A retrospective audit was undertaken. 123 ankle radiograph requests and radiographs taken between May and July 2018 were evaluated. Each ankle radiograph request including patient history and clinical examination was graded against the Ottawa Ankle Rule. The rule states that 1 point(s) indicates radiograph series; (1) malleolar and/or midfoot pain; (1) tenderness over the posterior 6cm or tip of the lateral or medial malleolus (ankle); (1) tenderness over the navicular or the base of the fifth metatarsal (foot); (1) unable to take four steps both immediately and in the emergency department [2]. Patients who score 0 do not need radiograph series. Each radiograph was reviewed if a fracture was present or not. The clinical audit identified 14 true positives where the Ottawa Ankle Rule scored 1 and the patient had an ankle fracture, and 2 false negatives (sensitivity 88%). There were 81 false positives, and 23 true negatives (specificity 22%). Therefore, a total of 23/123 ankle radiographs were unnecessary which is equivalent to 34.5 days of background radiation. The negative predictive value of the Ottawa Ankle Rule in this audit was 92%. The low rate of Ottawa rule utilisation may unnecessarily cause patient harm that should be addressed. An educational intervention with physicians combined with integration of the Ottawa rule scoring in ankle radiograph requests is planned with re-audit in 6 months

Despite of the significance of computed tomography (CT) images in surgery planning and guidance, CT scans are not always applicable due to high radiation exposure, particularly risky for children and youth. It is critical to reduce radiation exposure for high sensitive candidates and statistical atlas based approach has therefore been an alternative with minimal radiation exposure. We addressed the aforementioned challenges through statistical atlas constructions, 3D atlas to 2D radiography registration to get patient-specific models with minimal radiations and multiple-objective optimisation for planning the treatments. Statistical atlas can be employed to construct the global reference map. The atlas then can be registered to a pair of intra-operative fluoroscopy images for constructing a patient-specific model. In this way, we can reduce the radiation exposure to the patients significantly. To characterise shape variations, a statistical shape atlas is constructed using Point Distribution Model, by which a mean shape, modes of shape variation and shape variation are obtained. To construct the patient specific model from the statistical atlas, 3D-2D registration is essential and a back-projected ray based 3D-2D Iterative Closest Point registration method is investigated. Then the treatment planning module for optimal insertion is investigated to avoid critical zone and unnecessary punctures. The experiment shows the feasibility of the proposed method for atlas-based, image-guided orthopaedic interventions using minimal radiograph and optimal planning. The proposed framework can be extended to other potential applications and one example is for periacetabular osteotomy, particularly for young females which is of great importance to minimise radiation dose during surgical planning and navigation

Background. Heterotopic ossification (HO) is a known complication following total hip arthroplasty, with increased incidence in certain patient populations. Current prophylaxis options include oral non-steroidal anti-inflammatory drugs (NSAIDs) and radiation therapy, but an optimal radiation protocol has yet to be clearly defined. We performed a randomized, double-blinded clinical trial in high-risk total hip arthroplasty patients to determine the efficacy of 400 cGy versus 700 cGy doses of radiation. Methods. 147 patients at high risk for HO undergoing total hip arthroplasty (THA) at Rush-St. Luke's- Presbyterian medical center were randomized to either a single 400 cGy or 700 cGy dose of radiation. High risk was defined as diagnosis of diffuse idiopathic skeletal hyperostosis (DISH), hypertrophic osteoarthritis, ankylosing spondylitis, or history of previous heterotopic ossification. Radiation was administered over a 14 × 6 cm area of soft tissue and given on the first or second post-operative day. A blinded reviewer graded anterior-posterior (AP) and lateral radiographs taken immediately post-operatively and at a minimum of 6 months post-operatively. Progression was defined as an increase in Brooker classification from the immediate post-operative to the long-term post-operative radiograph. Operative data including surgical approach, use of cemented implants, revision surgery, and post-operative range of motion data were also collected. Results. A significantly greater portion of patients who received the 400 cGy dose demonstrated progression of HO than patients who received the 700 cGy dose. No pre-operative factors were associated with a higher rate of progression. Patients who progressed had less flexion on physical exam than patients who did not progress, but this was not clinically significant. Conclusion. To the authors' knowledge this is the largest randomized prospective study to date comparing two single-dosages of radiation treatment. 700 cGy demonstrates superiority over 400 cGy in preventing HO formation following total hip arthroplasty in high-risk patients and may be the more effective treatment in this population

Purpose: The use of radiology is integral to Orthopaedic Trauma surgery and there has been increasing dependence on image intensifiers in the operating room. A study was undertaken to assess the radiation exposure of the surgeon. Methods: One full time orthopaedic trauma surgeon has worn a dosimeter on his waist since November 1996, under a lead apron when using a large image intensifier and when using a mini C-arm. Since November 2001, a second dosimeter was worn at the neck, unshielded in all cases. Since June 2005, a ring dosimeter was worn on the dominant ring finger and the all surgical cases were prospectively documented in regard to the type of intensifier used and the amount of fluoroscopy used. Results: In the nine years of monitoring the truncal dosimeter has never recorded any radiation. In four years of monitoring the neck dosimeter has recorded 5.72 mSv (average 1.4 mSv / yr). In last 2 months (6 months data will be available at the time of presentation), 99 operative cases were done. In 31 cases no intra-operative radiology was used, 33 cases used a mini C-arm and in 35 cases a large C-arm was used. A total of 40.2 minutes of mini fluoro time (average 1.22 minutes / case) and 118.09 minutes of full sized C-arm fluoro time (average 3.37 minutes / case) was used. In these 2 months the ring dosimeter recorded 5.4 mSv of radiation (annualized dose 32.4 mSv). Conclusions: The International Commission on Radiological Protection annual recommended dose limits for “radiation workers” are: whole body 20 mSv, eyes 150 mSv and skin / hands 500 mSv. For members of the public these limits are 1 mSv, 15 mSv and 50 mSv, respectively. The exposure of an Orthopaedic Trauma surgeon fall well below the annual recommended dose limits in the industry but begin to approach the limits for the public. From this study it would appear to be safe not to use a lead apron for mini C-arm cases. The surgeons hands are exposed to the most radiation and strategies to reduce this exposure should be pursued

Introduction:. Conventional radiographic images are the gold standard method for postoperative evaluation of uncemented cups in patients with total hip arthroplasty. A conventional radiographic image of the pelvis gives a radiation dose of 0.7 mSv. Normally two images are needed. At present, dual energy CT is becoming more accessible in clinical practice and could allow lower radiation dose. Aim:. We wanted to assess what radiation dose was possible without sacrificing image resolution. Materials and methods:. We used a pig cadaver to assess a wide variety of radiation doses. A 13 mm “osteolysis” was drilled into the acetabulum dorsally-apically of the cup. A two mm wear was made on the apical part of the liner. There were bilateral uncemented hip replacements inserted into the pelvis to imitate a case with metal artefacts. Radiation doses for human adults were estimated from scans of Kyoto Kagaku PBU-60 with extra attenuation (prosthesis) with parameters from the cadaver. We used dual energy CT with 50% reduction of radiation dose. The images were enhanced using a software package called SAFIRE (Siemens). Similar softwares are available on all CT machines. Results:. The image quality was surprisingly good. Both wear and osteolysis were easy to detect without much disturbing metal artefact. Conclusion:. Dual energy computed tomography can produce high resulotion images with a radiation dose equivalent to two conventional radiographs of the pelvis

Aims. To monitor the performance of services for developmental dysplasia of the hip (DDH) in Northern Ireland and identify potential improvements to enhance quality of service and plan for the future. Methods. This was a prospective observational study, involving all infants treated for DDH between 2011 and 2017. Children underwent clinical assessment and radiological investigation as per the regional surveillance policy. The regional radiology data was interrogated to quantify the use of ultrasound and ionizing radiation for this population. Results. Evidence-based changes were made to the Northern Ireland screening programme, including an increase in ultrasound scanning capacity and expansion of nurse-led screening clinics. The number of infant hip ultrasound scans increased from 4,788 in 2011, to approximately 7,000 in 2013 and subsequent years. The number of hip radiographs on infants of less than one year of age fell from 7,381 to 2,208 per year. There was a modest increase in the treatment rate from 10.9 to 14.3 per 1,000 live births but there was a significant reduction in the number of closed hip reductions. The incidence of infants diagnosed with DDH after one year of age was 0.30 per 1,000 live births over the entire period. Conclusion. Improving compliance with the regional infant hip screening protocols led to reduction in operative procedures and reduced the number of pelvic radiographs of infants. We conclude that performance monitoring of screening programmes for DDH is essential to provide a quality service. Cite this article: Bone Joint J 2020;102-B(4):495–500