Aims. Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate femoral stem version in postoperative total hip arthroplasty (THA) patients and compare the accuracy of hipEOS to CT. We hypothesize that there will be no significant difference in calculated femoral stem version measurements between the two imaging methods. Methods. In this study, 45 patients who underwent THA between February 2016 and February 2020 and had both a postoperative CT and EOS scan were included for evaluation. A fellowship-trained musculoskeletal radiologist and radiological technician measured femoral version for CT and 3D EOS, respectively. Comparison of values for each imaging modality were assessed for statistical significance. Results. Comparison of the mean postoperative femoral stem version measurements between CT and 3D hipEOS showed no significant difference (p = 0.862). In addition, the two version measurements were strongly correlated (r = 0.95; p < 0.001), and the mean paired difference in postoperative femoral version for CT scan and 3D biplanar radiography was -0.09° (95% confidence interval -1.09 to 0.91). Only three stem measurements (6.7%) were considered outliers with a > 5° difference. Conclusion. Our study supports the use of low-dose biplanar radiography for the postoperative assessment of femoral stem version after THA, demonstrating high correlation with CT. We found no significant difference for postoperative femoral version when comparing CT to 3D EOS. We believe 3D EOS is a reliable option to measure postoperative femoral version given its advantages of lower radiation dosage and shorter examination time. Cite this article: Bone Joint J 2022;104-B(11):1196–1201

Aims

Ankle fracture fixation is commonly performed by junior trainees. Simulation training using cadavers may shorten the learning curve and result in a technically superior surgical performance.

Aims

We introduced a self-care pathway for minimally displaced distal radius fractures, which involved the patient being discharged from a Virtual Fracture Clinic (VFC) without a physical review and being provided with written instructions on how to remove their own cast or splint at home, plus advice on exercises and return to function.

Abstract. Background. Post operative radiographs following total joint arthroplasty are requested as part of routine follow up in many institutions. These studies have a significant cost to the local departments, in terms of financial and clinic resources, however, previous research has suggested they may not alter the course of the patients treatment. The purpose of this study was to assess the significance of elective post operative radiographs on changes in management of patients who underwent total joint arthroplasty. Method. All patients who underwent total knee arthroplasty and total hip arthroplasty at a District General Hospital from 2019 to 2020 were included. Data was collected retrospectively from medical records and radiograph requests. Alterations to clinical management based on radiographic findings were reviewed in clinic letters. Results. A total of 227 Total joint arthroplasty were retrieved. With 111(49%) total hip arthroplasty and 116 (51%) total knee arthroplasty. 54 were excluded due to having no clinical follow up and 173 met inclusion criteria. 56 (32%) had their post operative elective radiograph, while 93 (53.8%) patients had none. There were no abnormalities detected from the elective radiographs and none of the patients returned to the theatre. 24 patients (13%) presented with symptoms and had non-elective radiographs, 16 (67%) did not have any interventions and 8 (4.6%) required intervention and were taken to theatre. Discussion: Not performing these radiographs saves time, cost, and prevents unnecessary radiation exposure. In our institution, a 2-view joint radiograph costs £29 and takes roughly 15 minutes. This does not include indirect costs of additional clinic time and patient waiting time. In the larger context, the cost associated with elective radiographs is significant and our data suggests that routine post-operative radiographs are not beneficial as part of standard post-operative protocol for asymptomatic patients. However, performing imaging remains beneficial for patients who re-present with symptoms. Conclusion. Routine elective post-operative joint radiographs did not detect any true abnormalities. Information from elective radiographs has no clinical significance and did not change management. Therefore, this study recommends that there is no rationale requesting elective post-operative joint radiographs. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Malalignment is often postulated as the main reason for the high failure rate of total ankle replacements (TARs). Only a few studies have been performed to correlate radiographic TAR malalignment to the clinical outcome, but no consistent trends between TAR alignment parameters and the clinical outcome were found. No standard TAR alignment measurement method is present, so reliable comparison between studies is difficult. Standardizing TAR alignment measurements and increasing measurable parameters on radiographs in the clinic might lead to a better insight into the correlation between malalignment and the clinical outcome. This study aims to develop and validate a tool to semi-automatic measure TAR alignment, and to improve alignment measurement on radiographs in the clinic. A tool to semi-automatically measure TAR alignment on anteroposterior and lateral radiographs was developed and used by two observers to measure TAR alignment parameters of ten patients. The Intraclass Coefficient (ICC) was calculated and accuracy was compared to the manual measurement method commonly used in the clinic. The tool showed an accuracy of 76% compared to 71% for the method used during follow-up in the clinic. ICC values were 0.94 (p<0.01) and higher for both inter-and intra-observer reliability. The tool presents an accurate, consistent, and reliable method to measure TAR alignment parameters. Three-dimensional alignment parameters are obtained from two-dimensional radiographs, and as the tool can be applied to any TAR design, it offers a valuable addition in the clinic and for research purposes

Knee joint distraction (KJD) has been associated with clinical and structural improvement and synovial fluid (SF) marker changes. However, structural changes have not yet been shown satisfactorily in regular care, since radiographic acquisition was not fully standardized. AI-based modules have shown great potential to reduce reading time, increase inter-reader agreement and therefore function as a tool for treatment outcome assessment. The objective was to analyse structural changes after KJD in patients using this AI-based measurement method, and relate these changes to clinical outcome and SF markers. 20 knee OA patients (<65 years old) were included in this study. KJD treatment was performed using an external fixation device, providing 5 mm distraction for 6 weeks. SF was aspirated before, during and immediately after treatment. Weight-bearing antero-posterior knee radiographs and WOMAC questionnaires were collected before and ~one year after treatment. Radiographs were analysed with the Knee Osteoarthritis Labelling Assistant (KOALA, IB Lab GmbH, Vienna, Austria), and 10 pre-defined biomarker levels in SF were measured by immunoassay. Radiographic one-year changes were analysed and linear regression was used to calculate associations between changes in standardized joint space width (JSW) and WOMAC, and changes in JSW and SF markers. After treatment, radiographs showed an improvement in Kellgren-Lawrence grade in 7 of 16 patients that could be evaluated; 3 showed a worsening. Joint space narrowing scores and continuous JSW measures improved especially medially. A greater improvement in JSW was significantly associated with a greater improvement in WOMAC pain (β=0.64;p=0.020). A greater increase in MCP1 (β=0.67;p=0.033) and lower increase in TGFβ1 (β=-0.787;p=0.007) were associated with JSW improvement. Despite the small number of patients, also in regular care KJD treatment shows joint repair as measured automatically on radiographs, significantly associated with certain SF marker change and even with clinical outcome

Introduction. Routine radiographs in the follow-up of circular frames is commonplace, however the effect on clinical decision making is unclear. Previous work locally has suggested that >95% of radiographs, particularly at early time points, do not affect clinical management. This study was conducted to assess the impact of a transition to early remote follow-up on circular frame patients with limited radiographic assessment. Materials and Methods. Patients were identified from a prospective limb reconstruction database. Data were collected including the number of clinic appointments, type of clinic appointment, number of radiographs performed, and impact this had on clinical management. This was compared to our previous cohort of 85 patients undergoing standard follow-up. Results. Fourteen patients were eligible for inclusion (mean age 45, range 26–75). Circular frames were indicated for trauma (12), or limb reconstruction (2). Following introduction of remote follow-up, the mean number of face-to-face appointments reduced from 6.1 to 1.7 to the point of frame removal. Conversion from telephone follow-up to face-to-face follow-up was required in just one case where hardware failure occurred. The number of radiographs during treatment was reduced from a mean of 22 to 11 (range 4–20). Conclusions. Remote follow-up of circular frame patients was associated with significantly fewer radiographs and face-to-face appointments, without significantly increasing complications. We believe this is a safe and effective method of follow-up, optimising resource use in line with the NHS long term plan. Data collection is ongoing, and a larger cohort would be available for presentation

Polyethylene wear represents a significant risk factor for the long-term success of knee arthroplasty [1]. This work aimed to develop and in vivo validate an automated algorithm for accurate and precise AI based wear measurement in knee arthroplasty using clinical AP radiographs for scientifically meaningful multi-centre studies. Twenty postoperative radiographs (knee joint AP in standing position) after knee arthroplasty were analysed using the novel algorithm. A convolutional neural network-based segmentation is used to localize the implant components on the X-Ray, and a 2D-3D registration of the CAD implant models precisely calculates the three-dimensional position and orientation of the implants in the joint at the time of acquisition. From this, the minimal distance between the involved implant components is determined, and its postoperative change over time enables the determination of wear in the radiographs. The measured minimum inlay height of 335 unloaded inlays excluding the weight-induced deformation, served as ground truth for validation and was compared to the algorithmically calculated component distances from 20 radiographs. With an average weight of 94 kg in the studied TKA patient cohort, it was determined that an average inlay height of 6.160 mm is expected in the patient. Based on the radiographs, the algorithm calculated a minimum component distance of 6.158 mm (SD = 81 µm), which deviated by 2 µm in comparison to the expected inlay height. An automated method was presented that allows accurate and precise determination of the inlay height and subsequently the wear in knee arthroplasty based on a clinical radiograph and the CAD models. Precision and accuracy are comparable to the current gold standard RSA [2], but without relying on special radiographic setups. The developed method can therefore be used to objectively investigate novel implant materials with meaningful clinical cohorts, thus improving the quality of patient care

Introduction and Objective. Up to 30% of thoracolumbar (TL) fractures are missed in the emergency room. Failure to identify these fractures can result in neurological injuries up to 51% of the casesthis article aimed to clarify the incidence and risk factors of traumatic fractures in China. The China National Fracture Study (CNFS. Obtaining sagittal and anteroposterior radiographs of the TL spine are the first diagnostic step when suspecting a traumatic injury. In most cases, CT and/or MRI are needed to confirm the diagnosis. These are time and resource consuming. Thus, reliably detecting vertebral fractures in simple radiographic projections would have a significant impact. We aim to develop and validate a deep learning tool capable of detecting TL fractures on lateral radiographs of the spine. The clinical implementation of this tool is anticipated to reduce the rate of missed vertebral fractures in emergency rooms. Materials and Methods. We collected sagittal radiographs, CT and MRI scans of the TL spine of 362 patients exhibiting traumatic vertebral fractures. Cases were excluded when CT and/or MRI where not available. The reference standard was set by an expert group of three spine surgeons who conjointly annotated (fracture/no-fracture and AO Classification) the sagittal radiographs of 171 cases. CT and/or MRI were used confirm the presence and type of the fracture in all cases. 302 cropped vertebral images were labelled “fracture” and 328 “no fracture”. After augmentation, this dataset was then used to train, validate, and test deep learning classifiers based on the ResNet18 and VGG16 architectures. To ensure that the model's prediction was based on the correct identification of the fracture zone, an Activation Map analysis was conducted. Results. Vertebras T12 to L2 were the most frequently involved, accounting for 48% of the fractures. Accuracies of 88% and 84% were obtained with ResNet18 and VGG16 respectively. The sensitivity was 89% with both architectures but ResNet18 had a significantly higher specificity (88%) compared to VGG16 (79%). The fracture zone used was precisely identified in 81% of the heatmaps. Conclusions. Our AI model can accurately identify anomalies suggestive of TL vertebral fractures in sagittal radiographs precisely identifying the fracture zone within the vertebral body

Objectives. The radiographic union score for tibial (RUST) fractures was developed by Whelan et al to assess the healing of tibial fractures following intramedullary nailing. In the current study, the repeatability and reliability of the RUST score was evaluated in an independent centre (a) using the original description, (b) after further interpretation of the description of the score, and (c) with the immediate post-operative radiograph available for comparison. Methods. A total of 15 radiographs of tibial shaft fractures treated by intramedullary nailing (IM) were scored by three observers using the RUST system. Following discussion on how the criteria of the RUST system should be implemented, 45 sets (i.e. AP and lateral) of radiographs of IM nailed tibial fractures were scored by five observers. Finally, these 45 sets of radiographs were rescored with the baseline post-operative radiograph available for comparison. Results. The initial intraclass correlation (ICC) on the first 15 sets of radiographs was 0.67 (95% CI 0.63 to 0.71). However, the original description was being interpreted in different ways. After agreeing on the interpretation, the ICC on the second cohort improved to 0.75. The ICC improved even further to 0.79, when the baseline post-operative radiographs were available for comparison. Conclusion. This study demonstrates that the RUST scoring system is a reliable and repeatable outcome measure for assessing tibial fracture healing. Further improvement in the reliability of the scoring system can be obtained if the radiographs are compared with the baseline post-operative radiographs. Cite this article: Mr J.M. Leow. The radiographic union scale in tibial (RUST) fractures: Reliability of the outcome measure at an independent centre. Bone Joint Res 2016;5:116–121. DOI: 10.1302/2046-3758.54.2000628

Introduction. Cross table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). CTL measurements may differ by >10 degrees from CT scan measurements, but the reasons for this discrepancy are poorly understood. We compare anteversion measurements made on CTL radiographs and CT scans to identify spinopelvic parameters predictive of inaccuracy. Methods. THA patients (n=47) with preoperative spinopelvic radiographic analysis and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on post-operative CTL radiographs, and CT scans using 3D reconstructions of the pelvis. Patients were grouped by error (CTL-CT)>10° (n=11) or <10° (n=36), and spinopelvic mobility parameters were compared using t-tests. Correlation between error and mobility parameters was assessed with Pearson coefficient. Results. Patients with CTL error >10° (range 10–14) had stiffer lumbar spines with less lumbar flexion (38° vs 47°, p=0.03), greater sagittal imbalance measured by pelvic incidence-lumbar lordosis mismatch (6° vs −2°, p=0.04), more pelvic extension when seated (pelvic tilt −10° vs −2°, p=0.05), and greater change in pelvic tilt between supine and seated positions (13° vs 4°, p=0.04). The error of CTL measurements showed a positive correlation with increased CTL anteversion (r=0.5, p=0.001), standing lordosis (r=0.23, p=0.05), seated lordosis (r=0.4, p=0.01) and pelvic tilt change between supine and step-up positions (r=0.34, p=0.01). Discussion. Differences in spinopelvic mobility patterns may explain the variable accuracy of acetabular anteversion measurements on CTL radiographs. Patients with stiff spines and increased compensatory pelvic motion have less accurate measurements on CTL radiographs. Flexion of the contralateral hip is required to obtain clear CTL radiographs. In patients with a stiff lumbar spine, this movement may extend the pelvis and increase anteversion of the acetabulum on CTL views. Reliable analysis of acetabular component anteversion in this patient population may require advanced imaging with a CT scan

Over the last few years low dose digital radiography (DR) has all but replaced traditional chemical image processing. This appears to have created a paradigm shift in the suitability of intraoperative radiographic guidance for total hip arthroplasty. It is the purpose of this publication to describe our preferred technique and assess its reliability in achieving the desired parameters of a successful total hip arthroplasty. A consecutive prospective evaluation of 150 primary total hip arthroplasties employing intraoperative digital radiography was carried out. An anteroposterior pelvic radiograph with the patient in the lateral decubitus position was obtained for all hips. The orientation of the intraoperative film was matched to that of the preoperative pelvic radiograph. The image was taken after placement of the acetabular component and best estimate of femoral trial size, position, and head and neck length. The DR system produced an image within 6 seconds of exposure. This trial radiograph was then used to make adjustments. Given that the cassette does not have to be moved for image processing, a precise anteroposterior film was obtained by simply adjusting the operating table. Two to three minutes were allotted for each radiograph. Corrections to stem size, cup position, screw length and position, limb length, and offset were made based on this intraoperative radiograph. The final intraoperative image was then compared to a postoperative standard radiograph in supine position at 2 weeks after total hip arthroplasty to verify the accuracy of intraoperative digital radiography. Abduction angle, limb length, offset, and canal fit and fill were assessed for confirmation of the validity of the intraoperative imaging technique. Acetabular abduction angle was determined with a mean of 43 degrees (range, 35 to 48 degrees). The intraoperative measurement was within 3 degrees of the postoperative measurement in all cases. Adjustment of acetabular cup orientation was performed 10% of the time based on the intraoperative radiograph. Apposition was within 2 mm 100% of the time. Re-seating of the cup was carried out in one hip only. Femoral component was neutral in 92% and between 3 and 5 degrees of varus in 8%. Femoral component was upsized 55% of the time. Intraoperatively measured limb length discrepancy and offset were within 3 mm of the postoperative measurement in all hips. Intraoperative digital imaging is a reliable tool for achieving the desired radiographic results in THA. The technique is efficient and affordable. The high rate of success in this series suggests that this technology should contribute to a paradigm shift in the standard of care in total hip arthroplasty

Evaluation of patient specific spinopelvic mobility requires the detection of bony landmarks in lateral functional radiographs. Current manual landmarking methods are inefficient, and subjective. This study proposes a deep learning model to automate landmark detection and derivation of spinopelvic measurements (SPM).

A deep learning model was developed using an international multicenter imaging database of 26,109 landmarked preoperative, and postoperative, lateral functional radiographs (HREC: Bellberry: 2020-08-764-A-2). Three functional positions were analysed: 1) standing, 2) contralateral step-up and 3) flexed seated. Landmarks were manually captured and independently verified by qualified engineers during pre-operative planning with additional assistance of 3D computed tomography derived landmarks. Pelvic tilt (PT), sacral slope (SS), and lumbar lordotic angle (LLA) were derived from the predicted landmark coordinates. Interobserver variability was explored in a pilot study, consisting of 9 qualified engineers, annotating three functional images, while blinded to additional 3D information. The dataset was subdivided into 70:20:10 for training, validation, and testing.

The model produced a mean absolute error (MAE), for PT, SS, and LLA of 1.7°±3.1°, 3.4°±3.8°, 4.9°±4.5°, respectively. PT MAE values were dependent on functional position: standing 1.2°±1.3°, step 1.7°±4.0°, and seated 2.4°±3.3°, p< 0.001. The mean model prediction time was 0.7 seconds per image. The interobserver 95% confidence interval (CI) for engineer measured PT, SS and LLA (1.9°, 1.9°, 3.1°, respectively) was comparable to the MAE values generated by the model.

The model MAE reported comparable performance to the gold standard when blinded to additional 3D information. LLA prediction produced the lowest SPM accuracy potentially due to error propagation from the SS and L1 landmarks. Reduced PT accuracy in step and seated functional positions may be attributed to an increased occlusion of the pubic-symphysis landmark. Our model shows excellent performance when compared against the current gold standard manual annotation process.

The function of the knee joint is to allow for locomotion and is comprised of various bodily structures including the four major ligaments; medial collateral ligament (MCL), lateral collateral ligament (LCL), anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL). The primary function of the ligaments are to provide stability to the joint. The knee is prone to injury as a result of osteoarthritis as well as ligamentous and meniscal lesions. Furthermore, compromised joint integrity due to ligamentous injury may be a result of direct and indirect trauma, illness, occupational hazard as well as lifestyle. A device capable of non-invasively determining the condition of the ligaments in the knee joint would be a useful tool to assist the clinician in making a more informed diagnosis and prognosis of the injury. Furthermore, the device would potentially reduce the probability of a misdiagnosis, timely diagnosis and avoidable surgeries. The existing Laxmeter prototype (UK IPN: GB2520046) is a Stress Radiography Device currently limited to measuring the laxity of the MCL and LCL at multiple fixed degrees of knee flexion. Laxity refers to the measure of a ligament's elasticity and stiffness i.e. the condition of the ligament, by applying a known load (200N) to various aspects of the proximal tibial and thereby inducing tibial translation. The extent of translation would indicate the condition of the ligament. The Laxmeter does not feature a load applying component as of yet, however, it allows for the patient to be in the most comfortable and ideal position during radiographic laxity measurement testing. The entire structure is radiolucent and attempts to address the limitations of existing laxity measurement devices, which includes: excessive radiation exposure to the radiographic assistant, little consideration for patient ergonomics and restrictions to cruciate or collateral ligament laxity measurements. The study focusses on further developing and modifying the Laxmeter to allow for: the laxity measurement of all four major ligaments of the knee joint, foldability for improved storage and increased structural integrity. Additionally, a load applicator has been designed as an add-on to the system thereby making the Laxmeter a complete Stress Radiography Device. Various materials including Nylon, Polycarbonate, Ultra High Molecular Weight Polyethylene (UHMWPE) – PE 1000, and Acetal/ POM were tested, using the Low Dose X-ray (Lodox) scanner, to determine their radiolucency. All materials were found to be radiolucent enough for the manufacture of the Laxmeter structure as well as the load applicator in order to identify and measure the translation of the tibia with respect to the stationary femur. The Laxmeter allows for the measurement of the laxity of the MCL and LCL at multiple fixed degrees of flexion by providing the ideal patient position for testing. The next iteration of the device will present an affordable and complete Stress Radiography Device capable of measuring the laxity of all four major ligaments of the knee joint at multiple fixed degrees of flexion. Future work would include aesthetic considerations as well as an investigation into carbon-fibre-reinforced plastics

When performing scarf osteotomies some surgeons use intraoperative radiography and others do not. Our experience is that when using intraoperative radiography we often change the osteotomy position to improve the correction of the hallux valgus angle and sesamoid position. We report the results of a single surgeon series of 62 consecutive patients who underwent a scarf osteotomy for hallux valgus. The first 31 patients underwent surgery without the use of intraoperative radiographs and the subsequent 31 patients underwent surgery with the use of intraoperative radiographs, this reflects a change in the surgeons practice. Hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle and sesamoid position using the Hardy Clapham grading system were recorded. All patients had measurements recorded from weight baring radiographs taken pre operatively as well as at 6 and 12 weeks post operatively. Intraoperative measurements were also recorded for all patients in the intraoperative radiography group. The mean hallux valgus angle preoperatively was 28.5° in the control group and 30.5° in the intraoperative radiography group. The mean hallux valgus angle in the control group at 6 weeks was 12.4° and at 12 weeks was 12.6°. The mean hallux valgus angle in the intraoperative radiography group at 6 weeks was 10.5° and at 12 weeks was 9.8°. The median sesamoid position pre operatively was 4 for both groups. At 6 and 12 weeks the sesamoid position improved by a median of 1 position in the control group and 2 positions in the intraoperative radiography group (p<0.05). We recommend that surgeons who do not routinely use intraoperative radiography undertake a trial of this. We have found that the use of intraoperative radiography improves the correction of hallux valgus angle and sesamoid position. These have been shown to increase patient satisfaction and reduce recurrence

Introduction

There are nearly 500,000 people with undiagnosed diabetes mellitus in the UK. The incidental finding vascular calcification on plain radiographs in patients with undiagnosed diabetes has the potential to alter patient management in those presenting with pathology. We hypothesised that the presence of vascular calcification on plain radiographs of the foot may predict the diagnosis of diabetes. The primary aim of this case control study was to determine the positive predictive value of vascular calcification to diagnose diabetes. Secondary aims were to determine the odds of having diabetes dependent on other known risk factors for calcification.

Anteroposterior (AP) radiographs remain the standard of care for pre- and post-operative imaging during total hip arthroplasty (THA), despite known limitation of plain films, including the inability to adequately account for distortion caused by variations in pelvic orientation. Of specific interest to THA surgeons are distortions associated with pelvic tilt, as unaccounted for tilt can significantly alter radiographic measurements of cup position. Several authors have proposed methods for correcting for pelvic tilt on radiographs but none have proven reliable in a THA population. The purpose of our study was to develop a method for correcting pelvic tilt on AP radiographs in patients undergoing primary or revision THA. CT scans from 20 patients/cadaver specimens (10 male, 10 female) were used to create 3D renderings, from which synthetic radiographs of each pelvis were generated (Figure 1). For each pelvis, 13 synthetic radiographs were generated, showing the pelvis at between −30° and 30° of pelvic tilt, in 5° increments. On each image, 8 unique parameters/distances were measured to determine the most appropriate parameters for calculation of pelvic tilt (Figure 2). The most reliable and accurate of these parameters was determined via regression analysis and used to create gender-specific nomograms from which pelvic tilt measurements could be calculated (Figure 3). The accuracy and reliability of the nomograms and correction method were subsequently validated using both synthetic radiographs (n=50) and stereoradiographic images (n=58). Of 8 parameters measured, the vertical distance between the superior margin of the pubic symphysis and the transischial line (PSTI) was determined to be the most reliable (r=−0.96, ICC=0.94). Mean tilt calculated from synthetic radiographs (0.6°±18.6°) correlated very strongly (r=0.96) with mean known tilt (0.5°±17.9°, p=0.98). Mean pelvic tilt calculated from AP EOS images (3.2°±9.9°) correlated strongly (r=0.77) with mean tilt measured from lateral EOS images (3.8°±8.2°, p=0.74). No gender differences were noted in mean tilt measurements in synthetic images (p=0.98) or EOS images (p=0.45). Our method of measuring PSTI and POD on AP images and applying these measurements to nomograms provides a validated and reliable method for estimating the degree of pelvic tilt on AP radiographs during THA. For any figures or tables, please contact authors directly

The shape of the flexion gap in 20 normal knees was evaluated by axial radiography of the distal femur, and the results compared with those obtained in a previous study by MRI. The observed asymmetry was reduced by 29% using radiography, with a mean value of 3.6° (1.5° to 6.3°) compared with that obtained by MRI of 5.1° (2.6° to 9.5°), a mean discrepancy of 1.49°. The results obtained by radiography and MRI showed a strong correlation (r = 0.78). Axial radiography is acceptable for the evaluation of the flexion gap and is less expensive and more comfortable to perform than MRI. Additionally, no metallic artefact occurs when the radiological method is used for assessment after arthroplasty

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs.

Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures.

We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons).

We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries.

Diagnostic interpretation error of paediatric musculoskeletal (MSK) radiographs can lead to late presentation of injuries that subsequently require more invasive surgical interventions with increased risks of morbidity. We aimed to determine the radiograph factors that resulted in diagnostic interpretation challenges for emergency physicians reviewing pediatric MSK radiographs.

Emergency physicians provided diagnostic interpretations on 1,850 pediatric MSK radiographs via their participation in a web-based education platform. From this data, we derived interpretation difficulty scores for each radiograph using item response theory. We classified each radiograph by body region, diagnosis (fracture/dislocation absent or present), and, where applicable, the specific fracture location(s) and morphology(ies). We compared the interpretation difficulty scores by diagnosis, fracture location, and morphology. An expert panel reviewed the 65 most commonly misdiagnosed radiographs without a fracture/dislocation to identify normal imaging findings that were commonly mistaken for fractures.

We included data from 244 emergency physicians, which resulted in 185,653 unique radiograph interpretations, 42,689 (23.0%) of which were diagnostic errors. For humerus, elbow, forearm, wrist, femur, knee, tibia-fibula radiographs, those without a fracture had higher interpretation difficulty scores relative to those with a fracture; the opposite was true for the hand, pelvis, foot, and ankle radiographs (p < 0 .004 for all comparisons). The descriptive review demonstrated that specific normal anatomy, overlapping bones, and external artefact from muscle or skin folds were often mistaken for fractures. There was a significant difference in difficulty score by anatomic locations of the fracture in the elbow, pelvis, and ankle (p < 0 .004 for all comparisons). Ankle and elbow growth plate, fibular avulsion, and humerus condylar were more difficult to diagnose than other fracture patterns (p < 0 .004 for all comparisons).

We identified actionable learning opportunities in paediatric MSK radiograph interpretation for emergency physicians. We will use this information to design targeted education to referring emergency physicians and their trainees with an aim to decrease delayed and missed paediatric MSK injuries.

Background. Dislocation is a common complication following total hip arthroplasty (THA), and accounts for a high percentage of subsequent revisions. The purpose of this study was to develop a convolutional neural network (CNN) model to identify patients at high risk for dislocation based on postoperative anteroposterior (AP) pelvis radiographs. Methods. We retrospectively evaluated radiographs for a cohort of 13,970 primary THAs with 374 dislocations over 5 years of follow-up. Overall, 1,490 radiographs from dislocated and 91,094 from non-dislocated THAs were included in the analysis. A CNN object detection model (YOLO-V3) was trained to crop the images by centering on the femoral head. A ResNet18 classifier was trained to predict subsequent hip dislocation from the cropped imaging. The ResNet18 classifier was initialized with ImageNet weights and trained using FastAI (V1.0) running on PyTorch. The training was run for 15 epochs using ten-fold cross validation, data oversampling and augmentation. Results. The hip dislocation prediction classifier achieved the following mean performance: accuracy= 49.5(±4.1)%, sensitivity= 89.0(±2.2)%, specificity= 48.8(±4.2)%, positive predictive value= 3.3(±0.3)%, negative predictive value= 99.5(±0.1)%, and area under the receiver operating characteristic curve= 76.7(±3.6)%. Saliency maps demonstrated that the model placed the greatest emphasis on the femoral head and acetabular component. Conclusions. Existing prediction methods fail to identify patients at high risk of dislocation following THA. Our prediction model has high sensitivity and negative predictive value. Therefore, it can be helpful in rapid assessment of risk for dislocation following THA. The model further suggests radiographic locations which may be important in understanding the etiology of prosthesis dislocation

INTRODUCTION. Despite our best efforts, orthopaedic surgeons do not always achieve desired results in acetabular cup positioning in total hip arthroplasty. New advancements in digital radiography and image analysis software allow contemporaneous assessment of cup position in real-time during the surgical procedure. The purpose of this study was to describe and validate a technique in obtaining a true AP Pelvis radiograph in the lateral decubitus position to accurately assess cup position intra-operatively (Figure 1). METHODS. 350 consecutive patients undergoing THA through a soft-tissue sparing posterior approach were prospectively enrolled. Standard pre-operative supine radiographs were taken in the office to serve as a reference for intra-operative pelvic orientation and templating. Intra-operative AP Pelvis radiographs were obtained with the patient in the lateral decubitus position to appropriately match the pre-operative radiograph. Adjustments were made to correct for pelvic rotation by rotating the operating room table forward or backward. Radiographic beam angle adjustments allowed the surgeon to match pre-operative and intra-operative pelvic tilt (Figure 2). Two independent observers measured cup abduction angle. RESULTS. 95% of cups were placed within 30–50 degrees of abduction, with a mean angle of 38 degrees (STD +/− 5). 100% of cups measured post-operatively were placed within 3 degrees of their intra-operative measurement. Mean anteversion was 27.5 degrees (STD +/− 3.5). Intra-operative radiographs were repeated in 88% of cases in order to match to the pre-operative radiographs. The cup was repositioned in 28% of cases based on intra-operative measurements. Impingement during range of motion testing occurred in 3% of cases despite acceptable measurements, necessitating cup reposition. The intercross correlation coefficient between the two observers was 0.92. There was one dislocation reported in the 2-year follow-up. Changes in the pelvic inlet and outlet orientation changed the abduction angle measurement in a predictable way. We developed a formula and 3D model to predict the abudction angle based on the pelvic tilt, where a more outlet view would increase the abduction angle measurement (Figure 3). DISCUSSION AND CONCLUSION. Advancements in digital radiography allow for real-time cup position assessment, creating the opportunity for the surgeon to make the appropriate changes and confirm precise placement during the procedure. For figures/tables, please contact authors directly.

Pelvic x-ray is a routine part of the primary survey of Advanced Trauma Life Support (ATLS) guidelines. However, pelvic CT is the gold standard in the diagnosis of pelvic fractures. This study aims to confirm the safety of a modified ATLS algorithm omitting pelvic x-ray in hemodynamically stable polytraumatized patients with clinically stable pelvis, in favour of later pelvic CT scan.

A retrospective analysis of polytraumatized patients in our emergency room was conducted between 2005 and 2006. Inclusion criteria were blunt abdominal trauma, initial hemodynamic stability and clinically stable pelvis. We excluded patients requiring immediate intervention.

We reviewed the records of 452 patients. 91 fulfilled inclusion criteria (56% male, mean age 45 years). 43% were road traffic accidents and 47% falls. In 68/91 (75%) patients, both pelvic x-ray and CT examination were performed; the remainder had only pelvic CT. In 6/68 (9%) patients, pelvic fracture was diagnosed by pelvic x-ray. None false positive pelvic x-ray was detected. In 3/68 (4%) cases a fracture was missed in the pelvic x-ray, but confirmed on CT. 5 (56%) were classified type A fractures, and another 4 (44%) B 2.1 in computed tomography (AO classification). One A 2.1 fracture was found in a clinically stable patient who only received CT scan (1/23).

In hemodynamically stable patients with clinically stable pelvis, x-ray sensitivity is only 67% and it may safely be omitted in favor of a pelvic CT examination. The results support the safety and utility of our modified ATLS algorithm

Accurate measurement of pelvic tilt (PT) is critical in diagnosing hip and spine pathologies. Yet a sagittal pelvic radiograph with good quality is not always available. Studies explored the correlation between PT and sacro-femoral-pubic (SFP) angle from anteroposterior (AP) radiographs yet demonstrated conflicting conclusions about its feasibilities. This study aims to perform a cohort-controlled meta-analysis to examine the correlation between the SFP angle and PT and proposes an application range of the method.

This study searched PubMed, Embase, Cochrane, and Web of Science databases for studies that evaluated the correlation between SFP angle and PT. The Pearson's correlation coefficient r from studies were tabulated and compared. Pooled r for overall and gender/age (teenage or adult) controlled subgroup were reported using Fisher's Z transformation. Heterogeneity and publication bias were evaluated using Egger's regression test for the funnel plot asymmetry.

Eleven studies were recruited, with nine reported r (totalling 1,247 patients). The overall pooled r was 0.61 with high inter-study heterogeneity (I2 = 75.95%). Subgroup analysis showed that the adult group had a higher r than the teenage group (0.70 versus 0.56, p < 0.001). Although statistically insignificant (p = 0.062), the female group showed a higher r than the male group (0.72 versus 0.65).

The SFP method must be used with caution and should not be used in the male teenage group. The current studies did not demonstrate that the SFP method was superior to other AP landmarks correlating to PT. Identical heterogeneity was observed among studies, indicating that more ethnicity-segregated and gender-specific subgroup studies might be necessary. More data input analysing the errors will be useful.

Fluoroscopic C-arms are operated by medical radiography technologists (RTs) in Canadian operating rooms (ORs). While they do receive formal, accredited training, most of it is theoretical, rather than hands-on. During their first encounters in the OR, new RTs can experience difficulty achieving the radiographic views required by surgeons, often needing several scout X-rays during C-arm positioning. Furthermore, ambiguous language by surgeons often inadequately conveys their request. The result is often frustration, unnecessary radiation exposure, and added OR time. The purpose of this study was to evaluate the value of artificial X-rays in improving C-arm positioning performance, with inexperienced C-arm users. We developed an Artificial X-ray Imaging System (AXIS) that generates Digitally Reconstructed Radiographs (DRRs), or artificial X-ray images, based on the relative position of a C-arm and manikin. 30 participants were enrolled in the user study and performed four activities: an introduction session, an AXIS-guided evaluation, a non-AXIS-guided evaluation, and a questionnaire. The main goal of the study was to assess C-arm positioning performance with and without AXIS guidance. For each evaluation, the participants had to replicate a set of target X-ray images by taking real radiographs of the manikin with the C-arm. During the AXIS evaluation, artificial X-rays were generated at 2 Hz for guidance, while in the non-AXIS evaluation, the participants had to acquire real scout X-rays to guide them toward the correct view. For each imaging task the number of real X-rays and time required per task was recorded, and the C-arm's pose was tracked and compared to the target pose to determine positioning accuracy; these were averaged for each participant and condition. Hypothesis testing on the means and paired t-tests were carried out using a significance level of α=0.05. On average, users took significantly fewer real scout X-ray images (53% fewer (2.8 vs 6.0), p<0.001) when guided by AXIS. Lateral distance accuracy was improved by 10% for final C- arm positions and by 26% for the most accurate intermediate C-arm positions when guided by AXIS (p<0.05). There was no significant difference in average task time or angular accuracies between the AXIS and non-AXIS evaluations. Overall, we are encouraged by these findings and plan to further develop this system with the goal of deploying it both for training and intraoperative uses

Acetabular component orientation can directly influence dislocation rates, polyethylene wear, and revision rates. Precise placement has been found to occur in only 38–47% after total hip arthroplasty (THA). The recent introduction of digital radiography (DR) has enabled a paradigm shift in intra-operative imaging technology. Rather than deal with the cumbersome process of chemical image processing we can now acquire a high quality digital image in a matter of seconds. The functionality approaches that of fluoroscopy, or even a C-arm, however, a digital system can operate with lower radiation, higher resolution, and perhaps most importantly a larger field of view. These features make it very suitable for use during surgery. The purpose of this presentation is to illustrate the current intra-operative technique and share the overwhelmingly positive experience gathered over the past five years. Traditional THA employs use of post-operative radiography for “outcome assessment.” This unfortunately does not allow the surgeon to evaluate the relevant parameters and make necessary adjustments without returning to the operating room. Digital imaging, however, permits intra-operative guidance and “outcome control.” It provides an immediate and complete preview of what the post-operative film will show. There is now an opportunity to optimise component orientation, sizing, apposition, screw position, limb length, and offset, before leaving the operating room. This can be done with minimal intrusion on normal workflow, adding only a few minutes of operating time

Aims

The modified Radiological Union Scale for Tibia (mRUST) fractures score was developed in order to assess progress to union and define a numerical assessment of fracture healing of metadiaphyseal fractures. This score has been shown to be valuable in predicting radiological union; however, there is no information on the sensitivity, specificity, and accuracy of this index for various cut-off scores. The aim of this study is to evaluate sensitivity, specificity, accuracy, and cut-off points of the mRUST score for the diagnosis of metadiaphyseal fractures healing.

Identifying and restoring alignment is a primary aim of total knee arthroplasty (TKA). In the coronal plane, the pre-pathological hip knee angle can be predicted using an arithmetic method (aHKA) by measuring the medial proximal tibial angle (MPTA) and lateral distal femoral angle (aHKA=MPTA - LDFA). The aHKA is shown to be predictive of coronal alignment prior to the onset of osteoarthritis; a useful guide when considering a non-mechanically aligned TKA. The aim of this study is to investigate the intra- and inter-observer accuracy of aHKA measurements on long leg standing radiographs (LLR) and preoperative Mako CT planning scans (CTs).

Sixty-eight patients who underwent TKA from 2020–2021 with pre-operative LLR and CTs were included. Three observers (Surgeon, Fellow, Registrar) measured the LDFA and MPTA on LLR and CT independently on three separate occasions, to determine aHKA. Statistical analysis was undertaken with Bland-Altman test and coefficient of repeatability.

An average intra-observer measurement error of 3.5° on LLR and 1.73° on CTs for MPTA was detected. Inter-observer errors were 2.74° on LLR and 1.28° on CTs. For LDFA, average intra-observer measurement error was 2.93° on LLR and 2.3° on CTs, with inter-observer errors of 2.31° on LLR and 1.92° on CTs. Average aHKA intra-observer error was 4.8° on LLR and 2.82° on CTs. Inter-observer error of 3.56° for LLR and 2.0° on CTs was measured.

The aHKA is reproducible on both LLR and CT. CT measurements are more reproducible both between and within observers. The difference between measurements using LLR and CT is small and hence these two can be considered interchangeable. CT may obviate the need for LLRs and may overcome difficulties associated with positioning, rotation, body habitus and flexion contractures when assessing coronal alignment.

A radiographic method is described for making the diagnosis of talo-navicular subluxation before ossification of the navicular bone occurs. Seven basic combinations of deformities are thought to occur in the club foot. Radiography before operation enables the surgeon to determine which of these combinations exists in a particular foot, and radiography during operation enables him to determine wheter or not all the existing deformities have been corrected, and therefore whether or not the operation must be extended

Introduction

Low dose technology of an EOS scanner allows mechanical axis radiographs to be produced using a continuously moving x-ray emitting a thin beam to form a single image which includes all three joints, without the need for stitching. The aim of this study was to identify necessary improvements to enable effective interpretation of the radiographs, and to assess whether the quality of the radiographs varied by production method compared to a previous audit of CR and DR radiographs.

Despite our best efforts, orthopaedic surgeons do not always achieve desired results in acetabular cup positioning in total hip arthroplasty (THA). Although ideal abduction and anteversion angles vary depending on surgeon preference, patient factors and anatomy, studies have shown that improperly positioned cups lead to increased failure rates in THA. While there have been many technological advancements in THA, including using CT-guided and fluoroscopic techniques, the cost for the hospital and time required to use this technology sometimes force hospitals not to use them. New advancements in digital radiography and image analysis software allow contemporaneous assessment of cup position in real-time during the surgical procedure. Intra-operative, or “trial radiographs” with the patient in lateral decubitus position can be digitally manipulated to match pre-operative radiographs obtained with patients in the supine position to enable calculation of the abduction and anteversion angle in these patients. In our single surgeon experience, digital radiography takes approximately 4–6 seconds in order to obtain an AP pelvic radiograph. The use of the software to measure the cup position adds only 1–2 minutes to the operative time and minimises interference with workflow. The adjustments that can be made intra-operatively with this technology allow the surgeon to learn what factors in his surgical approach and technique are useful in achieving the desired component position. This allows the surgeon to have precise control over the cup position during the operation rather than experience disappointment and frustration while viewing the post-operative film. This cost-effective and efficient tool allows the surgeons to achieve the best results for their patients in real time without having to leave the operating room

Abstract

Bone ingrowth fixation of large diameter, beaded cobalt chromium cups is generally considered to be reliable but this is typically judged radiographically. To date, implant retrieval data of attached bone has been limited. This study evaluated correlations between the pre-revision radiographic appearance and the measured amount of bone attachment on one design of porous coated cup. Methods. Twenty-six monoblock, CoCr Birmingham Hip Resurfacing (BHR, Smith and Nephew, TN, USA) cups with macroscopic beads and hydroxyapatite coating were studied. Seventeen were revised for acetabular malposition with the remainder revised for femoral loosening (4), pain (1), infection (1), dislocation (1) or lysis (2). Median time to revision was 35 months (10 – 70 months). Ten patients were female; the median age of all patients was 54 years. The pre-revision radiographs were visually ranked for cup-bone integration as follows: 0 = none, 1 = < 50%, 2 = 50 – 75%, 3 = 76 – 95%, 4 = > 96% integration. Rankings were made for the superior and inferior aspects, without knowledge of the appearance of bone on the retrievals. The revised cups were photographed at an angle so the dome and the cup periphery were visualized. The area of bone in four equal segments in each of the superior and inferior aspects was measured with image analysis software. A probe was used to differentiate bone from soft tissue. Only bone that covered the beads was counted. Correlation coefficients were calculated for the radiographic and image analysis data. Results. Radiographically, most cups were assessed as having more than 50% of bone attachment and 7 cups were ranked as having almost total integration with bone. Only 2 cups were assessed radiographically as fully loose. Measured total bone attachment ranged from none to 55%. Superior and inferior percent ingrowth were highly correlated (corr=0.68, p<0.001) but there was no correlation between percent bone and x-ray rank (inferior corr=0.01, p=0.96; superior corr=0.23, p=0.26). There was no correlation between cup malpositioning as a reason for revision and x-ray integration ranking (superior p=0.34; inferior p=0.80). Discussion. Despite the radiographic appearance of good fixation, there was little or no correlation between percent area of actual bone attachment and x-ray appearance. One study limitation is the assumption that attached bone was indeed integrated with the beads as destructive sectioning was not done to verify this. Published autopsy retrieval studies have shown that even a small amount of actual ingrowth can provide clinically successful fixation. Another possible limitation was the variable quality of the radiographs. Never-the-less these results raise questions about the accuracy of radiographic analysis of bone fixation. The possibility that inadequate fixation is a cause for pain leading to revision should be considered even when the radiographic appearance indicates otherwise

We have previously developed a radiographic technique, the oblique posterior condylar view, for assessment of the posterior aspect of the femoral condyles after total knee arthroplasty. The purpose of this study was to confirm the validity of this radiographic view based upon intra-operative findings at revision total knee arthroplasty. Lateral and oblique posterior condylar views were performed for 11 knees prior to revision total knee arthroplasty, and radiolucent lines or osteolysis of the posterior aspect of the femoral condyles were identified. These findings were compared with the intra-operative appearance of the posterior aspects of the femoral condyles. Statistical analysis showed that sensitivity and efficacy were significantly better for the oblique posterior condylar than the lateral view. This method can, therefore, be considered as suitable for routine follow-up radiographs of the femoral component and in the pre-operative planning of revision surgery

Introduction. In prosthetic knee surgery, the axis of the lower limb is often determined only by static radiographic analysis. However, it is relevant to determine if this axis varies during walking, as this may alter the stresses on the implants. The aim of this study was to determine whether pre-operative measurement of the mechanical femorotibial axis (mFTA) varies between static and dynamic analysis in isolated medial femorotibial osteoarthritis. Methods. Twenty patients scheduled for robotic-assisted medial unicompartmental knee arthroplasty (UKA) were included in this prospective study. We compared three measurements of the coronal femorotibial axis: in a static and weightbearing position (on long leg radiographs), in a dynamic but non-weightbearing position (intra-operative acquisition during robotic-assisted UKA), and in a dynamic and weightbearing position (during walking by a gait analysis). Results. There was no significant difference in the mFTA between radiological (173.9 ± 3.3°), robotic (174.4 ± 3.4°), and gait analysis (172.9 ± 5.1°) measurements (p < 0.05). Conclusion. There is no significant variation in varus between lying, standing, and while walking in patients who are candidates for medial UKA. This study also allows us to validate the accuracy of the robotic system in varus estimation, and to rely on intra-operative planning as it also reflects the dynamic knee under load

The accurate assessment of compartmental involvement in degenerative arthritis of the knee is important when planning operative treatment. Standard radiographic techniques often fail to define the degree of involvement of the less affected tibiofemoral compartment. The use of stress radiography in the preoperative assessment of 30 knees with degenerative arthritis is described and the radiographic findings correlated with the changes found at arthrotomy

Introduction: It could be shown that an ample number of classical hip parameters for radiographic quantification of hip morphology on anteroposterior (AP) pelvic radiographs vary significantly with individual pelvic tilt and rotation. This could be proven not only for classical hip parameters (e.g. the lateral centre edge angle) but also for more recently described radiographic features such as acetabular retroversion. The resulting misdiagnosis and misinterpretation can potentially impair a correct therapy for the patient. We developed fast and easy-to-use computer software to perform three-dimensional (3D) analysis of the individual hip joint morphology using two-dimensional (2D) AP pelvic radiographs. Landmarks extracted from the radiograph were combined with a cone beam x-ray projection model and a strong lateral pelvic radiograph to reconstruct 3D hip joints. Twenty-five parameters including quantification of femoral head coverage can be calculated for a neutral orientation. The aim of the study was to evaluate the validity of this method for tilt and rotation correction of the acetabular rim and associated radiographic parameters. Methods: The validation comprised three steps:. External validation;. internal validation; and. intra-/interobserver analysis. A series of x-rays of 30 cadaver pelves mounted on a flexible holding device were available for step 1 and 2. External validation comprised the comparison of radiographical parameters of the cadaver hips when determined with our software in comparison with CT-based measurements or actual radiographs in a neutral pelvic orientation as gold standard. Internal validation evaluated the consistency of the parameters when each single pelvis was calculated back from different random orientations to the same neutral pelvic position. The intra-/interobserver analysis investigated the reliability and reproducibility of all parameters with the help of 100 randomized, blinded AP pelvic radiographs of a consecutive patient series. Results:. All but one parameter (acetabular index) showed a substantial to almost perfect correlation with the CT-measurements. Internal validity was substantial to almost perfect for all parameters. There was a substantial to almost perfect reliability and reproducibility of all parameters except the acetabular index. Conclusion: The software could be shown to be an accurate, reliable and reproducible method for correction of AP pelvic radiographs. This computer-assisted method allows standardized evaluation of all relevant radiographic parameters for detection of anatomic morphologic differences. It will be used to study the influence of pelvic malorientation on the radiographic appearance of each individual parameter. In addition, it allows evaluating the clinical significance of standardizing pelvic parameters

Axial radiographs were obtained under valgus and external rotation stress at 45° of knee flexion with and without contraction of the quadriceps muscle in order to assess the dynamics of patellar subluxation or dislocation. The radiography was performed on 82 knees in 61 patients with patellofemoral instability, and on 44 normal knees. The lateral patellofemoral angle and the congruence angle were measured and compared with the conventional Merchant views. Both parameters showed greater differences between symptomatic and normal knees on the stress radiographs obtained without quadriceps contraction. There was a major difference in the lateral patellofemoral angles between the groups, which clearly distinguished symptomatic knees from normal controls. Congruence angles on stress radiography had a significant correlation with the functional scores obtained after a period of conservative treatment and a positive correlation with the frequency of patellar subluxation. When the quadriceps contracted, two patterns of patellar shift were observed. While the patella reduced into the trochlear groove in all normal knees and about 70% of the symptomatic knees, contraction of the quadriceps caused further subluxation of the patella in the remaining symptomatic knees. All the knee joints which showed this displacement failed to respond to conservative treatment and eventually required surgical treatment. Thus, this technique of stress radiography is a simple, cost-effective and useful method of evaluating patellar instability and predicting the prognosis

An uncomplicated, quantitative method of determining density from X-rays would be of extreme value to clinicians. In this study we perform a thorough assessment of applying a step wedge to grey level calibration method to X-rays obtained using Computed Radiography (CR). An Aluminium step wedge of ten, 5mm-thick steps was X-rayed with a Fuji CR system together with a knee phantom (3M) at various energy and Fuji processing settings. Automatic detection of the steps by means of the Hough transform was used to assess optimum CR settings. Background variation due to the anode Heel effect was evaluated by acquiring an “empty field” X-ray at different energy settings and with copper filtering. The effects of beam hardening were considered with a custom-made phantom which was also used to assess correcting for soft tissue and bone thickness. X-rays taken at higher energy settings and with wider windowing imaged the widest number of steps (nine) and gave the best accuracy in modelling the step thickness to grey level relationship. Fitting a straight line to the log of the net grey levels gives an excellent model of the data (R2 = 0.99). X-rays of copper sheeting show that automatic histogram analysis is performed by the Fuji CR system, which can have unpredictable effects on aluminium thickness to grey level relationship. Background variation in the anode-cathode direction due to the Heel effect was corrected with a 1D exponential model (R2 = 0.99), allowing position-independent measurements to be obtained. Correcting for bone thickness, soft tissue and beam hardening further improves measurement quality. Use of step wedge calibration to provide quantitative information on plain X-rays without altering their clinical quality is possible using digital radiography. However, a thorough assessment of the entire X-ray process is necessary to achieve accurate and comparable information

Two critical steps in achieving optimal results and minimizing complications (dislocation, lengthening, and intra-operative fracture) are careful pre-operative planning and more recently, the option of intra-operative imaging in order to optimise accurate and reproducible total hip replacement. The important issues to ascertain are relative limb length, offset and center of rotation. It is important to start the case knowing the patient's perception of their limb length. Patient perception is equally important, if not more important, than the radiographic assessment. On the acetabular side, the teardrop should be identified and the amount of reaming necessary to place the inferior margin of the acetabular component adjacent to the tear drop should be noted. Superiorly the amount of exposed metal that is expected to be seen during surgery should be measured in millimeters. Once the key issues of limb length, offset, center of rotation, and acetabular component position relative to the native acetabulum have been confirmed along with the expected sizing of the acetabular and femoral components, it is critical that the operative plan is reproduced at the time of surgery and this can best be consistently performed with the use of intra-operative imaging. Advances in digital imaging now make efficient, cost-effective assessment of hip replacement possible. Embedded software allows accurate confirmation of the pre-operative plan intra-operatively when correction of potential errors is easily possible. Such technology is now mature after years of clinical use and studies have confirmed its success in avoiding outliers and achieving optimal results

Radiological examination is a useful tool in assessing osteoarthritis (OA) in the knee. We have compared the extent of osteoarthritis in the knee graded on radiographs and by intraoperative observation to determine if there is significant difference with relevance to preop-erative planning. Radiographs for fifty-eight patients were graded for OA under blind conditions using the Ahlback classification system and direct measurement of the medial and lateral joint spaces. Intraoperative assessment of the corresponding joint surfaces was performed under blind conditions by a separate surgeon and graded using the Outerbridge classification system. OA was found to be more common in the medial compartment than the lateral, both on radiographs and intraoperatively. Spearman correlation coefficient for the medial compartment comparing joint space narrowing and intraoperative assessment was −0.545. For the lateral compartment the Spearman correlation coefficient was lower at –0.406. Positive predictive values for OA in the medial and lateral compartments on radiography were 90% and 66.67% respectively. Negative predictive values for OA in the medial and lateral compartments on radiography were 44.74% and 34.69% respectively. Conclusion: We have demonstrated that although radiographs have reasonable to good accuracy at showing OA in both compartments the absence of OA on radiographs does not correlate well with the absence of OA in the knee. This is of importance when planning operations, particularly unicompartmental knee replacement, as intraoperative findings of bilateral disease will change the operation required

Radiological measurements are an essential component of the assessment of outcome following knee arthroplasty. However, plain radiographic techniques can be associated with significant projectional errors because they are a two-dimensional (2D) representation of a three-dimensional (3D) structure. Angles that are considered within the target zone on one film may be outside that zone on other films. Moreover, these parameters can be subject to significant inter-observer differences when measured. The aim of our study therefore was to quantify the variability between observers evaluating plain radiographs following Unicompartmental knee arthroplasty. Twenty-three observers, made up of Orthopaedic Consultants and trainees, were asked to measure the coronal and sagittal alignment of the tibial and femoral components from the post-operative long-leg plain radiograph of a Unicompartmental knee arthroplasty. A post-operative CT scan using the low dose Imperial knee protocol was obtained as well and analysed with 3D reconstruction software to measure the true values of these parameters. The accuracy and spread of the pain radiographic measurements were then compared with the values obtained on the CT. On the femoral side, the mean angle in coronal alignment was 1.5° varus (Range 3.8, SD 1, min 0.1, max 3.9), whereas the mean angle in sagittal alignment was 8.6° of flexion (Range 7.5, SD 1.5, Min 3.7, Max 11.2). The true values measured with CT were 2.4° and 11.0° respectively. As for the tibial component, the mean coronal alignment angle was 89.7° (Range 11.6, SD 3.3, Min 83.8, Max 95.4), and the mean posterior slope was 2.4° (Range 8.7, SD 1.6, Min -2, Max 6.7). The CT values for these were 87.6° and 2.7° respectively. We conclude that the plain radiographic measurements had a large scatter evidenced by the wide ranges in the values obtained by the different observers. If only the means are compared, the plain radiographic values were comparable with the true values obtained with CT (that is; accuracy was good) with differences ranging from 0.3° to 2.4°. The lack of precision can be avoided with the use of CT, particularly with the advent of low-dose scanning protocols

The recent introduction of digital radiography has enabled a paradigm shift in intra-operative imaging technology. Rather than deal with the cumbersome process of chemical image processing we can now acquire a high quality digital image in a matter of seconds. The functionality approaches that of fluoroscopy, or even a C-arm, however, a digital system can operate with lower radiation, higher resolution, and perhaps most importantly a larger field of view. These features and the greater ability for post-acquisition, digital image enhancement make it very suitable for use during surgery. The purpose of this presentation is to illustrate the intra-operative technique and share the overwhelmingly positive experience gathered over the past few years. The current paradigm in total hip arthroplasty (THA) employs use of post-operative radiography for “outcome assessment.” This unfortunately does not allow the surgeon to evaluate the relevant parameters and make necessary adjustments without returning to the operating room. The new paradigm, however, permits intra-operative guidance and “outcome control.” We now have an opportunity to add a “trial radiograph” to our practice of performing a trial reduction. This provides an immediate and complete preview of what the post-operative film will show. There is now an opportunity, during the course of any hip arthroplasty, to optimise component orientation, sizing, apposition, screw position, limb length, and offset, before leaving the operating room. This can be done with minimal intrusion on normal workflow, adding only a few minutes of operating time

Aims

The primary aim of this study was to report the radiological outcomes of patients with a dorsally displaced distal radius fracture who were randomized to a moulded cast or surgical fixation with wires following manipulation and closed reduction of their fracture. The secondary aim was to correlate radiological outcomes with patient-reported outcome measures (PROMs) in the year following injury.

Purpose: To determine the need for routine serial radiographs in the management of forearm fractures in children. Material and Methods: A binational study was conducted in 202 consecutive children with closed forearm fractures. In the 91 patients with stable fractures that did not require reduction, clinical and radiographic examination was performed one week after the start of treatment and again on cast removal 4–6 weeks later. In the remaining 111 patients who underwent closed reduction, an additional X-ray was taken two weeks after cast placement. Outcome was defined as the occurrence of redisplacement. Results: Redisplacement occurred during the first 2 weeks of cast management in 9 of the children who required reduction and in none of the children who did not. Conclusion: Radiographs should be performed one week after cast placement for greenstick or complete fractures that do not require reduction, and repeated at 2 weeks from start of treatment for fractures that require reduction. They need not be performed on cast removal, if clinical examination does not show signs of nonunion or malalignment. The adoption of these recommendations will lead to more cost-effective management and will spare children unnecessary radiographic exposure

Iterative finite element (FE) models are used to simulate bone remodelling that takes place due to the surgical insertion of an implant or to simulate fracture healing. In such simulations element material properties are calculated after each iteration of solving the model. New material properties are calculated based on the results derived by the model during the last iteration. Once the FE model has gone through a number of such iterations it is often necessary to assess the remodelling that has taken place. The method widely used to do this is to analyse element Young's modulus plots taken at particular sections through the model. Although this method gives relevant information which is often helpful when comparing different implants, the information is rather abstract and is difficult to compare with patient data which is commonly in the form of radiographs. The authors suggest a simple technique that can be used to generate synthetic radiograph images from FE models. These images allow relatively easy comparisons of FE derived information with patient radiographs. Another clear advantage of this technique is that clinicians (who are familiar with reading radiographs) are able to understand and interpret them readily. To demonstrate the technique a three dimensional (3D) model of the proximal tibia implanted with an Oxford Unicompartmental Knee replacement was created based on CT data obtained from a cadaveric tibia. The model's initial element material properties were calculated from the same CT data set using a relationship between radiographic density and Young's modulus. The model was subject to simplified loading conditions and solved over 365 iterations representing one year of in vivo remodelling. After each iteration the element material properties were recalculated based on previously published remodelling rules. Next, synthetic anteroposterior radiographs were generated by back calculating radiographic densities from material properties of the model after 365 iterations. A 3D rectangular grid of sampling points which encapsulated the model was defined. For each of the elements in the FE model radiographic densities were back calculated based on the same relationships used to calculate material properties from radiographic densities. The radiographic density of each element was assigned to all the sampling grid points within the element. The 3D array of radiographic densities was summed in the anteroposterior direction thereby creating a 2D array of radiographic densities. This 2D array was plotted giving an image analogous to anteroposterior patient radiographs. Similar to a patient radiograph denser material appeared lighter while less dense material appeared darker. The resulting synthetic radiographs were compared to patient radiographs and found to have similar patterns of dark and light regions. The synthetic radiographs were relatively easy to produce based on the FE model results, represented FE results in a manner easily comparable to patient radiographs, and represented FE results in a clinician friendly manner

Accurate evaluation of lower limb coronal alignment is essential for effective pre-operative planning of knee arthroplasty. Weightbearing hip-knee-ankle (HKA) radiographs are considered the gold standard. Mako SmartRobotics uses CT-based navigation to provide intra-operative data on lower limb coronal alignment during robotic assisted knee arthroplasty. This study aimed to compare the correlation between the two methods in assessing coronal plane alignment.

Patients undergoing Mako partial (PKA) or total knee arthroplasty (TKA) were identified from our hospital database. The hospital PACS system was used to measure pre-operative coronal plane alignment on HKA radiographs. This data was correlated to the intraoperative deformity assessment during Mako PKA and TKA surgery.

443 consecutive Mako knee arthroplasties were performed between November 2019 and December 2021. Weightbearing HKA radiographs were done in 56% of cases. Data for intraoperative coronal plane alignment was available for 414 patients. 378 knees were aligned in varus, and 36 in valgus. Mean varus deformity was 7.46° (SD 3.89) on HKA vs 7.13° (SD 3.56) on Mako intraoperative assessment, with a moderate correlation (R= 0.50, p<0.0001). Intraoperative varus deformity of 0-4° correlated to HKA measured varus (within 3°) in 60% of cases, compared to 28% for 5-9°, 17% for 10-14°, and in no cases with >15° deformity. Mean valgus deformity was 6.44° (SD 4.68) on HKA vs 4.75° (SD 3.79) for Mako, with poor correlation (R=0.18, p=0.38).

In this series, the correlation between weightbearing HKA radiographs and intraoperative alignment assessment using Mako SmartRobotics appears to be poor, with greater deformities having poorer correlation.

Introduction. Alumina-on-alumina bearings exhibit low wear rates in vitro and one commonly used ceramic implant is the Trident system (Stryker, Mahwah, NJ). There are some reports of incomplete seating of the ceramic liner in the Trident acetabular shell. However, it is often difficult to detect incomplete seating intraoperatively. We sought to prevent incomplete seating using intraoperative radiography. Materials and Methods. We retrospectively reviewed 19 hips in 17 patients who had undergone primary total hip arthroplasty using a Trident shell with a metal-backed alumina liner between 2007 and 2010. There were 16 women and 1 man, with an average age of 45.7 years. Preoperative diagnosis revealed 14 cases of osteoarthritis and 5 cases of osteonecrosis. All procedures were performed using a posterolateral approach with PSL cups. The minimum follow-up time was 12 months (average 28 months). All procedures included an intraoperative anteroposterior view radiograph to evaluate cup seating. If incomplete seating was recognized we reinserted the liner. Postoperatively, radiographs (supine anteroposterior and cross table lateral views) and computed tomography were performed in all cases in order to assess any residual incomplete seating. We investigated whether it was possible to avoid incomplete seating using intraoperative radiography. Results. Six (32%)of 19 hips had evidence of incomplete seating. Of these, 3 revealed incomplete seating on intraoperative radiography, 2 were reinserted adequately, and the liner was replaced with a polyethylene liner in one case. Postoperative radiography revealed incomplete seating in 3 cases. One hip had become correctly seated as shown by follow-up radiography at 3 months and the other hips remained incompletely seated for the follow up period. The location of the gap between the socket and liner caused by incomplete seating was inferomedial in all cases, as seen on the intraoperative anteroposterior view radiographs. We were able to avoid incomplete seating in all of these cases except for one, which was missing the gap. Cases in which the location of the gap was anterior could not be diagnosed by intraoperative radiographs, and were diagnosed postoperatively. Incomplete seating was seen in 3 of 9 cases that used a 2.8 mm shell thickness, and in 3 of 10 cases that used a 3.8 mm thickness. No case had complete dislocation or failure of the ceramic liner. There were no revision surgeries. Discussions. Although there have been no published case reports regarding complete dislocation or failure of the ceramic liner caused by incomplete seating, adverse influences that are caused by incomplete seating remain uncertain. Some reports describe that incomplete seating was potentially attributed to poor exposure, bony and soft tissue impingement, and cup deformity. The attempt to avoid incomplete seating using intraoperative radiography was effective in cases where medial or lateral gaps were seen. However, it was ineffective in cases where gaps were anterior or posterior. Trident system ceramic liners need to be used with care to avoid incomplete seating

Background. Component positioning in total hip arthroplasty (THA) is critical to achieve optimal patient outcomes. Recent literature has shown acetabular component positioning may be inaccurate using traditional techniques. Robotic-assisted THA is a recent platform introduced to decrease the risk of malpositioned components. However, to date, a paucity of data is available comparing the intra-operative component position generated by the navigation system to post-operative radiographs. Purpose. The purpose of this study was to compare the component position measurements of a navigation system, used during robotic-assisted THA, to component position measurements obtained on post-operative radiographs. Methods. Intra-operative component position measurements for acetabular inclination, acetabular anteversion, leg length change, and offset change for 145 patients were recorded. Pre-operative and post-operative radiographs of the same 145 patients were then measured for the same parameters. A comparison of component position provided by the navigation system and radiographic data was then performed. Sub-group analyses of posterior and direct anterior measurements were performed. Results. Correlation between the navigation system and post operative radiographs was within 10° for 95.9% of cases for inclination and 96.6% for anteversion. Correlation within 10 mm of radiographic-measured values occurred in 97.7% of cases for change in leg length and 94.0% for change in global offset. 100% of the cases ended up with radiographic leg length discrepancy of less than 10 mm. Conclusion. The intra-operative component position data obtained from the navigation system utilized during robotic-assisted THA demonstrated correlated well with component position data obtained from radiographs

Aims. To assess the long-term effect of distal trochanteric transfer (DTT) on the clinical and radiographic outcomes of patients with Legg-Calvé-Perthes’ disease (LCPD) following a varus derotational osteotomy (VDRO). Patients and Methods. For this single centre cross-sectional retrospective study we analysed the data of 22 patients (24 hips) with LCPD who had greater trochanteric overgrowth (GTO), following a VDRO performed in our institution between 1959 and 1983. GTO was defined as an articular trochanteric distance (ATD) of < 5 mm. We compared the radiographic and clinical outcomes of patients who underwent DTT for GTO (ten patients, ten hips) with those who did not (12 patients, 14 hips). Age at presentation was 6.9 years (4 to 10) and 8.0 years (3.2 to 12) respectively. Symptoms associated with the hip and general quality of life were assessed using the Harris hip score (HHS) and the Short Form (SF)-36 questionnaires. Results. At long-term follow-up of the DTT group, the ATD was 21.7 mm (standard deviation (. sd. ) 9.8) and the centro-trochanteric distance (CTD) was 13.8 mm (. sd. 8.3). In the control group the ATD was -0.6 mm (. sd. 7.8) and the CTD was 32.5 mm (. sd. 10.2). These differences were statistically significant (p < 0.001). The mean HHS and SF-36 scores were 68.4 (. sd. 25.0) and 62.0 (. sd. 27.7) for the DTT group and 73.2 (. sd. 24.2) and 73.3 (. sd. 21.5) for the control group, respectively. There was no statistically significant difference in the HHS (p = 0.63) or SF-36 score (p = 0.25). There were four patients who had undergone hip arthroplasty in the DTT group (40%) and one patient (7.1%) in the control group (p = 0.07). The mean age at the time of arthroplasty was 45.3 years (42.1 to 56.5) and 43.6 years respectively. Six patients in the DTT group suffered from moderate to severe osteoarthritis (Tönnis grade 2 or 3) compared with eight patients in the control group (60% versus 57.1%, p = 0.61). Conclusion. Although DTT improved the radiographic results in the long-term follow-up of patients with GTO following VDRO, there was no clinical benefit seen in the HHS, SF-36 or incidence of osteoarthritis compared with patients who had not undergone DTT. Cite this article: Bone Joint J 2017;99-B:987–92

Aim: To describe the radiographic findings of soft tissue sarcoma. Materials and Method: The retrospective review of 100 consecutive patients with a histological diagnosis of primary soft tissues sarcoma of the extremities. Results: Fifty five patients had plain radiographs at initial presentation. This was mainly due to the fact that most patients were tertiary referrals or had other initial imaging. Histological diagnosis in these patients was: liposarcoma in 24 patients, leiomyosarcoma in 8, undifferentiated spindle cell sarcoma in 5, malignant schwannoma in 4, synovial sarcoma in 4, MFH in 2, fibrosarcoma in 2, haemangiopericytoma, epithelioid sarcoma, malignant GCT, melanoma and spindle cell histiocytoma in one. The upper limb was involved in 18 patients and the lower limb was involved in 37. Thirty-five (63.6%) patients had a visible soft tissue mass on plain film. Eleven had mineralisation within the soft tissue mass and seven had either bone involvement or periosteal response. Those with a distinct soft tissue mass and evidence of fat content on plain film were noted to be diagnosis of liposarcoma in 86.7% of the cases. Mineralization was noted in synovial sarcoma (2), liposarcoma (3), leiomyosarcoma (1), MFH (2) and poorly differentiated sarcomas (2). Conclusion: The plain radiograph is useful in assessing soft tissue tumour and abnormality is seen in 2/3 of cases reviewed. Mineralization as a radiographic finding features in malignant sarcoma notably liposarcoma. With tumours demonstrating fat on plain film this can correlate with MRI and facilitate surgical treatment avoiding biopsy

After a unicompartmental Oxford knee replacement, a clear lateral radiographic view of the components may be obtained without the shadow of prosthetic components in the other compartment. Radiographs of 20 knees were studied; with the patient supine and the muscles relaxed, views with the knee at full extension and 90 degrees of flexion were obtained and the movement of the meniscal bearings over this range of flexion was measured. The bearings were found to move backwards on the tibia through an average distance of 4.4 mm (range 0.0 to 13.5 mm) in the medial compartment and 6.0 mm (range 1.6 to 13.0 mm) in the lateral compartment. These movements were in the same direction as that observed in cadaver specimens but smaller in magnitude. At 90 degrees of flexion, radiographs were obtained with the tibia twisted manually to the limits of medial and lateral rotation. The average movement of the bearings between these extremes was found to be 6.6 mm in the medial compartment and 5.1 mm in the lateral; their movements on the tibia were in opposite directions in the two compartments. Bearing movement was still present in knees examined five years after operation

A prospective clinical investigation to determine the optimum knee flexion angle for the ‘skyline’ patellofemoral joint radiograph. Plain radiography of the patello-femoral joint includes the axial or ‘skyline’ radiograph. The optimum knee flexion angle for making this image remains unclear. We therefore performed a prospective clinical study in which patients underwent three skyline radiographs with knee flexion angles of 30(or minimal flexion), 50 and 90 degrees. The patients were new patients, aged between 12 and 30, presenting to a knee clinic with anterior knee pain. Two observers evaluated the radiographs, making a standardised series of measurements. Blinding was organised so that the observers were unable to use any information other than the radiographic image alone. One observer evaluated all the films on two separate occasions to allow calculation of intra- and interassessor agreement. There were 67 knees from 46 patients. There was a high level of intra- and inter-observer agreement. There were a number of patients in which the radiographic appearance of the patello-femoral varied markedly between the different views; in all cases the abnormality was best demonstrated by the 30-degree view. There were however a number of minimal flexion views in which the film contained incomplete information because part of the patello-femoral joint was missing from the image. We conclude that whilst a minimal flexion skyline view is the most sensitive method for the detection of patellar tilt and subluxation, not all knees can be successfully imaged at the required position. A flexible approach is therefore needed, to obtain satisfactory images at minimal flexion

Purpose. Radial head implant over-lengthening, a common cause of capitellar wear and clinical failure, is difficult to diagnose using radiographs of the injured elbow. The purpose of this study was to determine if a novel measurement technique based on contralateral elbow radiographs, termed the RACER method, could be used to accurately estimate the magnitude of radial head implant over-lengthening. Part I of this study examined the side-to-side consistency of radiographic landmarks used in the measurement technique. Part II of this study validated the technique using simulated radial head implant over-lengthening in a cadaveric model. Method. Part I: A side-to-side comparison of elbow joint dimensions was performed in 50 patients (100 radiographs). Part II: Radial head prostheses of varying lengths (0,+2mm,+4mm,+6mm,+8mm) were implanted in 4 paired cadaveric specimens (8 elbows). Radiographs were obtained and measurements were performed by 2 examiners blinded to implant size to determine if contralateral radiographs could diagnose and provide a valid estimate of the magnitude of implant over-lengthening. Intra and inter-rater reliability was determined. Results. No significant side-to-side differences (p>0.2) in radiographic measurements were identified between paired elbows. The RACER measurement technique using contralateral radiographs was successful in predicting the implant size (1mm) in 104 of 120 (87%) of scenarios tested. The sensitivity of the technique, the ability of the test to correctly identify over-lengthening when it was present within 1mm, was 98%. The intra-rater agreement for a single orthopaedic surgeon measuring on 2 separate occasions was excellent (ICC>0.90). The inter-rater agreement between two separate surgeons was also excellent, with the 95% lower confidence interval exceeding 0.90 in all cases. Conclusion. A novel measurement technique based on contralateral elbow radiographs can be used to diagnose and calculate the magnitude of radial head implant over-lengthening. Clinical Significance: Implantation of an incorrectly sized radial head prosthesis is not uncommon. The described technique can be used to effectively diagnose and determine the magnitude of over-lengthening

Background: Acetabular retroversion has been proposed to contribute to the development of osteoarthritis of the hip. For the diagnosis of this condition, conventional AP pelvic radiographs may represent a reliable, easily available diagnostic modality as they can be obtained with a reproducible technique allowing the anterior and posterior acetabular rims to be visible for assessment. This study was designed to. establish a method to directly quantify anatomic acetabular version on AP pelvic radiographs and to. determine the validity of the radiographic “cross-over-sign” to detect acetabular retroversion. Methods: Using 43 desiccated pelves (86 acetabuli) the anatomic acetabular versions were measured at three different transverse planes (cranially, centrally and caudally). From these pelves, standardized AP pelvic radiographs were obtained. To directly measure central acetabular version (AV), a modified radiographic method is introduced for the use of AP pelvic radiographs. Moreover, the validity of the radiographic “cross-over-sign” to detect cranial acetabular retroversion was determined. Results: The mean central and caudal anatomic AV were approximately 20°, the mean cranial AV was 8°. Cranial retroversion (AV < 0°) was present in 19 of 86 hips (22%). A linear correlation was found between the central and cranial AV. Below 10° of central AV, all acetabuli were cranially retroverted. Between 10° and 20°, 30% of the acetabuli were cranially retroverted and above 20°, only one of 45 acetabuli was cranially retroverted. The radiographic measurement of the central AV (20.3° ± 6.5) correlated strongly with the anatomic AV (20.1° ± 6.4). The sensitivity of the ‘cross-over-sign’ to detect an cranial acetabular anteversion of less than 4° was 96%, its specificity 95%, and the positive predictive and negative predictive values 90% and 98%, respectively. Conclusions: The cranial AV is on average 12° lower than the central AV, with the latter directly measurable from AP pelvic radiographs. A central AV of less than 10° was associated with cranial retroversion. The presence of a positive ‘cross-over-sign’ is a highly reliable indicator of cranial AV of < 4°

Aim:. To Determine Whether Maximal Rib Prominence Measured On Lateral Radiographs Can Be Used As A Surrogate To Rib Rotation Determined By Surface Tomography (Quantecscanning) In Assessment Of Spinal Rotation. Method:. Patients With Adolescent Idiopathic Scoliosis Underwent Plain Lateral Radiographs And Quantec Scans. Maximal Rib Prominence On The Lateral Radiograph Was Defined Pre- And Post-Operatively By Distance From Most Posterior Aspect Of The Rib To The Facet Joint And Instrumented Rod, Respectively. Rib Rotation Was Measured By Surface Tomography Quantec Scan Using The Suzuki Method. This Was Then Repeated At A Later Time And By An Additional Investigator To Assess Intra- Observer And Inter-Observer Variability. The Correlation Between Maximal Rib Prominence And The Suzuki Ratio Was Determined. Results:. 20 Patients, Median Age 15 Years, Were Evaluated. The Correlation Coefficient Between Radiograph Determined Maximal Rib Prominence And Quantec Derived Suzuki Ratio Was 0.68, R2=0.46 (See Figure). Discussion:. There Was A Weak Positive Correlation Between Radiograph Determined Maximal Rib Prominence And Quantec Derived Suzuki Ratio. Further Investigation In A Larger Cohort Is Warranted. Conflict Of Interest Statement: No conflict of interest

It is difficult to establish the diagnosis of an injured shoulder if only one radiographic projection is used. We have compared two lateral projections, the Neer trans-scapular and the apical oblique in 80 patients; the radiographs were presented randomly to 10 casualty officers and nine radiologists. The apical oblique view was found to permit more accurate diagnosis of fractures and of dislocation by both groups

We studied the development of ball-and-socket deformity of the ankle by arthrography and radiography in 14 ankles of ten patients with congenital longitudinal deficiency of the fibula accompanied by various anomalies. The mean follow-up was for 18 years 10 months. In three ankles in infants less than one year old the lateral and medial sides of the ankle were already slightly round. In another seven ankles the ball-and-socket appearance developed before the age of five years. This was thought to be due to osseous coalition which limits eversion and inversion. In another four ankles in children who were over the age of one year at the initial examination, the deformity was demonstrated by arthrography and radiography at their first examination. Ball-and-socket deformity accompanied by tarsal coalition is an acquired deformity secondary to limitation of movement of the subtalar and midtarsal joints. It has completely developed by about five years of age

Introduction. Total hip replacement (THR) is a very common procedure performed for the treatment of osteoarthritis of the hip. The aim of THR is to restore function and quality of life of the patients, by restoring femoral offset, leg length, centre of rotation, and achieving stability, to avoid dislocation postoperatively. Method. We aimed to perform preoperative assessment of femoral offset on anteroposterior (AP) radiographs of the hip, and on corresponding CT scans, for patients undergoing primary THR. Patients were positioned according to a standardised protocol prior to obtaining radiographs of the hip and CT scan. Inter- and intra-observer reliability was evaluated between 3 observers of differing levels of seniority – an orthopaedic trainee, a fellow, and a consultant. CT scan measurements of offset were performed by one consultant radiologist. The researchers measuring radiographic offset were blinded to the results of the CT measurements. Results. In the entire cohort of 50 patients, the mean femoral offset was 44 mm on AP radiographs of the hip and 45 mm on CT scans. No significant difference in mean femoral offset was seen between AP radiographs of the hip and CT. There was good inter and intra-observer reliability in the measurement of femoral offset on AP radiographs of the hip. There was no difference in the radiographic measurements between observers of differing levels of seniority. Conclusions. Accurate restoration of femoral offset is very important in the good functioning of THR. AP radiographs of the hip are accurate, and should be routinely obtained preoperatively for templating, prior to THR

Digital radiographs are routinely used for preoperative planning, both in trauma and elective patients; particularly in preoperative templating for total hip replacement. Traditional wisdom holds that radiographs are oversized, though the degree to which this occurs is unclear. Although digital templating systems offer the use of calibration markers, this option is not always availed. We aimed to ascertain the typical magnification in departmental xrays of the hip, both to determine the typical degree of magnification as well as ascertain its consistency. All patients undergoing dynamic hip screw fixation (DHS) in our unit over the past 12 months were identified. Using the PACS system, subsequent xrays of the patient with the implant in situ were identified; both anteroposterior abdominal and pelvic films were used. The width of a standard DHS screw (12.5 mm) was compared with the width measured on the xrays to determine a magnification factor. 164 patients were identified, of these 39 had undergone DHS fixation with subsequent xrays. 3 films were focused on the abdomen but provided good coverage of the hip also. 2 xrays were excluded – both due to limited quality. The average magnification was 26.4% (range 15.5%–42%). There was limited consistency between images. Radiographs are a core investigation in the assessment of the orthopaedic patient. The advent of picture archiving and communications systems (PACS) has allowed the enterprising surgeon to pre-emptively plan their surgical technique and implant use. However, the utility of non-calibrated images in planning implant size is limited by variation in magnification. Surgeons should be cautious in using such images to guide their implant usage

Background. A cautious outlook towards neck injuries is the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce the unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods. This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs done for suspected neck injuries were included in the study. Data on patient demographics, Canadian Cervical Spine rule, cervical spine radiography results and further visits after discharge were recorded. Results. 14 patients were included in the high risk category according to the Canadian Cervical Spine rule. 100 patients were assessed according to the low risk category. If the Canadian Cervical Spine rule was applied, there was a significant reduction in cervical spine radiographs (p<0.001) as 86/100 patients (86%) in the low risk category would not have needed cervical spine radiograph. 2/100 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion. Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and cost benefits

Aims

Limb-lengthening nails have largely replaced external fixation in limb-lengthening and reconstructive surgery. However, the adverse events and high prevalence of radiological changes recently noted with the STRYDE lengthening nail have raised concerns about the use of internal lengthening nails. The aim of this study was to compare the prevalence of radiological bone abnormalities between STRYDE, PRECICE, and FITBONE nails prior to nail removal.

Assessment of stability in ankle fractures is key in deciding the most appropriate mode of treatment. Stress radiographs have been suggested as a potential method for assessing ankle stability in patients with apparently isolated lateral malleolar fractures. Whilst stress radiographs have been found to be both sensitive and specific in cadaveric experiments, recent clinical studies have suggested that a widened medial clear space (MCS) on stress radiographs may not equate to a functionally unstable ankle. We aimed to assess whether patients with an apparently isolated lateral malleolar fracture on presentation but with a positive gravity stress radiograph (GSR) could be successfully managed non-operatively. A prospective study of all patients with lateral malleolar fractures presenting to our orthopaedic trauma department was undertaken. Patients with an oblique distal fibular fracture pattern and no obvious MCS widening on routine radiographs underwent a GSR. Measurements of the radiographic MCS and superior clear space (SCS) were made and compared with published criteria. 155 patients were included in the study and treated non-operatively fully weight bearing in either a cast or removable boot. Following fracture union all patients had both anatomical alignment of the ankle mortise and good or excellent function. The MCS of 79% of these patients was found to be greater than 4 mm with 19% greater than 6 mm. All of these patients were successfully managed non-operatively. The currently used criteria for measurements on stress radiographs result in high numbers of false positive cases. This may be leading to unnecessary surgery. Further investigation is required in order to identify other clinical or radiographic criteria that may be of use in the assessment of functional ankle stability after fracture

It is believed by some that knee radiographs may underestimate the extent of osteoarthritis. Often severe changes are noted at arthroscopic assessment despite the observation of preserved joint spaces on plain radiographs. This has important implications regarding the indications for different types of partial joint replacement if damage is underestimated. Aims:. To determine the correlation if any between radiographic findings and arthroscopic findings. To determine which radiographs are consistently useful for assessment of osteoarthritis and to determine the limitations. To identify the proportions of patients with certain patterns of damage who might be suitable in the future for different types of partial replacement. Methods and patient selection: The pre-operative radiographs and intra-operative articular surface mappings were collected for 100 consecutive patients undergoing prospectively audited outcome of arthroscopic debridement. All the patients examined were aged 40 and above with knee pain. The intra-operative findings and any work done (debridement of meniscal tears or cartilage flap tears) were also recorded on zoned articular maps and meniscal diagrams. The pre-operative radiographs (AP standing, lateral, Rosenberg and skyline views) were examined and graded using the Kellgren and Lawrence grading system. Results: Correlations made between arthroscopic findings and AP standing views yielded a sensitivity of 72% and specificity of 64%. The positive predictive value was 91% and negative predictive value was 32%. Rosenberg views were better at predicting the presence of osteoarthritis (sensitivity 76%, specificity 88%, positive predictive value 97%, negative predictive value 44%). Skyline views were found to particularly unreliable in assessment of patello-femoral damage. Analysis of the actual patterns of articular damage found at arthroscopy did show that it is possible to identify cohorts of patients who may in future be suitable for different types of partial replacement. Conclusions: Radiographs and in particular skyline views are limited in terms of sensitivity and specificity in the prediction of osteoarthritis. Rosenberg views offer better prediction of osteoarthritis compared with weight bearing AP radiographs. Arthroscopy carried out in any event for clinical indications appears to offer useful additional information regarding indications for future surgery

Anteroposterior (AP) pelvic radiographs are the standard tool used for pre-operative planning and post-operative evaluation during total hip arthroplasty (THA). The accuracy of this imaging modality is, however, limited by errors in pelvic orientation and image distortion. Pelvic obliquity is corrected for by orienting measurements to a reference line such as the interteardrop line or the interischial line, while several methods for correcting for pelvic tilt have been suggested, with varying levels of success. To date, no reliable method for correcting for pelvic rotation on pelvic imaging is available. The purpose of this study was to evaluate a novel method for correcting pelvic rotation on a standard anteroposterior (AP) radiographs. Computed tomography (CT) scans from 10 male cadavers and 10 female THA patients were segmented using 3D Slicer and used to create 3D renderings for each pelvis. Synthetic AP radiographs were subsequently created from the 3D renderings, using XRaySim. For each pelvis, images representing pelvic rotation of 30° left to 30° right, at 5° increments were created. Four unique parameters based on pelvic landmarks were used to develop the correction method: i) the horizontal distance from the upper edge of the pubic symphysis to the sacroiliac joint midline (PSSI), ii) the ratio of the horizontal distances from the upper edge of the pubic symphysis to the outer lateral border of both obturator foramina (PSOF), iii) the width ratio of the obturator foramina (OFW) and iv) the ratio of the horizontal distance from each anterior superior iliac spine to the sacroiliac joint midline (ASISSI). The relationships between the chosen parameters and pelvic rotation were investigated using a series of 260 (13 per pelvis) synthetic AP radiographs. Male and female correction equations were generated from the observed relationships. Validation of the equations was done using a different set of 50 synthetic radiographs with known degrees of rotation. In males, the PSSI parameter was most reliable in measuring pelvic rotation. In females, PSOF was most reliable. A high correlation was noted between calculated and true rotation in both males and females (r=0.99 male, r=0.98 female). The mean difference from the male calculated rotation and true rotation value was 0.02°±1.8° while the mean difference from the female calculated rotation and true rotation value was −0.01°±1.5°. Our correction method for pelvic rotation using four pelvic parameters provides a reliable method for correcting pelvic rotation on AP radiographs.

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The inability to consistently position components is associated with the major complications of hip replacement including instability, wear, liner breakage, limb length discrepancy, and limited function. This was a major catalyst for the demise of hard-on-hard bearings. The greatest challenge is accurate, reproducible positioning of acetabular component which is obtained in a surprisingly low percentage of cases. Other major issues include consistently obtaining proper limb length, offset, component sizing, and complete seating without fracture of either the acetabulum or the femur. There are two approaches to this issue; to either use virtual reality which applies technology that provides surrogates to direct visualization of components. The major issues with computer assisted techniques include questions of accuracy and increased time and cost. The other approach is to utilise intraoperative imaging which has been the gold standard traditionally, however, previously it has been a challenge to utilise intraoperative imaging without adding substantial time and cost. Historically intraoperative imaging has not been adopted because it disrupts work flow, the quality of images has been inadequate, and it has added too much additional time to allow for a series of repeat radiographs to be obtained. Modifications of existing portable imaging that utilise direct radiography (DR plate technology) allow for intraoperative images that display within seconds. Imbedded software allows measurement of all parameters of interest. Three or 4 systems are currently in use, and this is not virtual reality but it is the gold standard. Advantages include higher quality images, faster service speed, minimal impact on OR work flow, eventual reduction in operating costs, elimination of processing of chemicals and film room/storage room, and most importantly the elimination of outliers and return to the operating room due to unexpected findings on recovery room radiographs. Intraoperative imaging has been utilised at a number of centers in recent years and has led to numerous intraoperative changes to optimise component implantation in a surprisingly high percentage of cases. Advances in technology have made intraoperative digital imaging a practical feasible strategy to avoid outliers that increase complications and compromise results. The rapidly evolving technology makes this a very attractive option for optimising total hip component placement. In addition it is an excellent teaching tool that is rapidly embraced by residents and fellows and is an extremely effective in eliminating outliers

There is no consensus on the benefit of arthroscopically assisted reduction of the articular surface combined with fixation using a volar locking plate for the treatment of intra-articular distal radial fractures. In this study we compared the functional and radiographic outcomes of fluoroscopically and arthroscopically guided reduction of these fractures. Between February 2009 and May 2013, 74 patients with unilateral unstable intra-articular distal radial fractures were randomised equally into the two groups for treatment. The mean age of these 74 patients was 64 years (24 to 92). We compared functional outcomes including active range of movement of the wrist, grip strength and Disabilities of the Arm, Shoulder, and Hand scores at six and 48 weeks; and radiographic outcomes that included gap, step, radial inclination, volar angulation and ulnar variance. . There were no significant differences between the techniques with regard to functional outcomes or radiographic parameters. The mean gap and step in the fluoroscopic and arthroscopic groups were comparable at 0.9 mm (standard deviation. (sd). 0.7) and 0.7 mm (. sd. 0.7) and 0.6 mm (. sd. 0.6) and 0.4 mm (. sd. 0.5), respectively; p = 0.18 and p = 0.35). . Arthroscopic reduction conferred no advantage over conventional fluoroscopic guidance in achieving anatomical reduction of intra-articular distal radial fractures when using a volar locking plate. Cite this article: Bone Joint J 2015; 97-B:957–62

We compared goniometric assessment of passive ankle movement with radiographic measurements in 100 normal ankles. Significant differences were recorded in both dorsiflexion and plantarflexion; clinical measurements overestimated the range of movement. For scientific documentation of tibiotalar mobility, radiographic measurements should be used

Background: A cautious outlook towards neck injuries has been the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce the unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods: This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs done for suspected neck injuries were included in the study. Data on patient demographics, Canadian Cervical Spine rule, cervical spine radiography results and further visits after discharge were recorded. Results: 14 patients were included in the high risk category according to the Canadian Cervical Spine rule. 100 patients were assessed according to the low risk category. If the Canadian Cervical Spine rule was applied, there was a significant reduction in cervical spine radiographs (p< 0.001) as 86/100 patients (86%) in the low risk category would not have needed cervical spine radiograph. 2/100 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion: Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and cost benefits

Radiographs are frequently ordered following acute knee injury. However, it is suggested that only 6 % of patients with a knee trauma have a fracture. Decision rules such as the Ottawa rules and the Pittsburgh rules have been developed to reduce the unnecessary use of radiographs following knee injury. We prospectively reviewed all acute knee injury patients who were referred to our clinic from the emergency department over a 3 month period. The reason for ordering radiographs was analysed. The Ottawa and the Pittsburgh rules were applied to individual patients to evaluate the need for radiographs. In patients with a diagnosis of fracture, the accuracy of the Ottawa and the Pittsburgh rules was studied. A total, of 106 patients were referred to the acute knee clinic from the emergency department. 95.28 % (101) of these patients had radiographs of their knee in the emergency department. Five (4.72%) patients had a fracture of their knee and all these cases, the Ottawa and the Pittsburgh knee rules for ordering radiographs was fulfilled. In a vast majority of cases without any fracture, the clinical reason for ordering radiographs was not clear. Using the Ottawa rules for knee radiography 25.47% (27) radiographs could be avoided without missing a fracture. Using the Pittsburgh rules, 30.19 % (32) knee radiographs could be avoided without missing a fracture. The Ottawa and the Pittsburgh rules have a high sensitivity for the detection of knee fractures. Use of these rules can aid efficient clinical evaluation of the knee in an emergency situation without adverse clinical outcome. They may also have an implication on reducing the work load of radiology department and reduction of health costs

A series of 75 patients who had undergone anterior cervical fusion between 1965 and 1977 were reviewed. The patients were divided into two groups: those in Group A had had the level of fusion indicated by cine radiography, whereas in Group B the level had been determined by plain radiographs and clinical symptoms and signs. Results showed that cine radiography was the more accurate diagnostic technique. Accurate diagnosis of the level to be fused, the careful clinical selection of patients and sound bony union were found to be vital to the success of anterior cervical fusion. The incidence of pseudarthrosis was significant in single-level fusions and was even greater in double-level fusions and in patients with a history of trauma, especially whiplash injuries. It was rare to develop recurrence of symptoms in adjacent levels after fusion of a level localised by cine radiography

Aim: The aim of this study was to asses the accuracy of skyline radiographs in the assessment of the patellofemoral joint, when compared to open intraoperative assessment. Methods: Eighty nine patients undergoing knee replacement surgery were included in the study. Skyline radiographs were obtained preoperatively. These radiographs were assessed and graded by an experienced musculoskeletal radiologist using the Altman and Ahlbäck classifications. The grades were calculated for both the medial and lateral facets of the PFJ. Intraoperative assessment of the Patellofemoral joint was undertaken at the time of surgery. The damage was graded using the modified Collins classification (0: Normal, 1: Superficial damage, 2: Partial thickness cartilage loss, 3: Focal Full thickness cartilage loss < 2cm2, 4: Extensive full thickness cartilage loss < 2cm2). Data was obtained for the Medial Facet, Lateral Facet and Trochlea. Results: Spearman’s rank correlation coefficient between the radiographic and macroscopic changes within the lateral PFJ were poor with both the Altman 0.22 (p=0.0350) and Ahlbäck 0.24 (p=0.018). The correlation of the medial PFJ was slightly better with a coefficient for Altman 0.42 (P< 0.0001) and Ahlbäck 0.34 (P> 0.001). Conclusion: In conclusion skyline radiographs provide a poor to moderate preoperative assessment of the degree of osteoarthritis within the patella-femoral joint. This has significant implications for establishing radiographic criteria for planning patella-femoral joint replacement

The purpose of this study was to describe a clinical evaluation of the etiological factors in osteochondritis dissecans (OCD) of the knee from radiographic and arthroscopic findings. Twenty-two knees of 20 patients (16 male and 4 female, 16.1 years old in average at surgery) with symptomatic OCD of the femoral condyle were studied. The medial femoral condyles were affected in 16 knees of 14 patients (medial group) and the lateral femoral condyle in 6 knees of 6 patients (lateral group). These two groups were compared using radiological location and arthroscopic findings. In radiography, the location of OCD was classified in accordance with Cahill et al. (1989). On the anteroposterior view, five zones were numbered 1 to 5 from medial to lateral. On the lateral view, three zones were labeled A,B and C from anterior to posterior. In the medial group, the locations of OCD were 23BC(12), 2BC(1), 23ABC(1) and 23C(2); 14(88%) of 16 knees involved in non-meniscal area. In the lateral group, the locations of OCD were 45C(4), 5C(1) and 4BC(1); 5(83%) of 6 knees involved in meniscal area. In arthroscopy the medial group did not have medial meniscal tear, while the lateral group had 5 lateral meniscal lesions of 6 knees; 3 discoid meniscus (2 with tear and 1 without tear), 2 bucket-handle type tear and one no meniscal lesion. Lateral meniscal lesions (with or without discoid) might cause OCD of the lateral femoral condyle. In the medial femoral condyle, we thought that OCD did not relate to meniscal lesions

The medial displacement osteotomy of Chiari has an established place in the management of older children and adults with severe hip dysplasia. The results claimed for the operation are, however, variable. There have also been reports of sciatic nerve lesions. In this study ten cadavers were operated upon. Chiari osteotomy was performed upon five, and five acted as controls. The hemipelvis was removed from each cadaver; each specimen was deep-frozen and sectioned transversely. The distance of the sciatic nerve from the nearest bony point was measured in each section and the results were recorded graphically. A further radiographic and photographic study was performed to determine whether apparent displacement at the osteotomy might be misleading. The conclusion was drawn that the sciatic nerve is angulated at the osteotomy and further endangered by the risk of bone splintering at the sciatic notch. The radiographic study suggested that some poor clinical results may be explained by a radiological artefact, because there is a tendency for the osteotomy to hinge posteriorly at the sciatic notch opening anteriorly like a book. Radiographs may suggest excellent medial displacement whereas in fact the femoral head is very poorly covered

Polyethylene wear is the most important risk factor affecting the durability of total knee arthroplasty. We developed a new method of measuring wear of the tibial polyethylene insert in total knee arthroplasty (TKA) on standard standing radiographs. Methods: We developed a new method of measuring the shortest distance between the femoral component and the tibial metal tray taking its 3-D position into consideration. The accuracy of the method was examined in 3 conditions. An in vitro examintion measured the thickness of the polyethylene on radiographs of a new PFC prosthesis set on a table. The radiographs were taken from various directions. An in vivo examination measured the polyethylene thickness on patient discharge radiographs of 78 knees. These measurements were compared with known thicknesses of the used inserts. In the third study, wear of the tibial polyethylene insert was measured retrospectively in a series of 84 PFC TKAs with follow-up of 2 to 10 years (6.6 years on average). Results: The average measurement error was 0.05 mm (SD 0.09 mm) in the in vitro study and 0.14 mm (SD 0.17 mm) in the in vivo study using discharge radiographs. In the series of 84 PFC TKAs, impending failure occurred in 7 knees, 4 of which were revised. Radiographically measured wear of the tibial insert was significantly greater in these failed TKAs than in the other TKAs. The radiographic measurements were well correlated with 3-D measurements of 4 retrieved inserts. Discussion: Although the radiographic measurement of the tibial insert in TKA was less accurate than that of the socket in THA, it is useful enough to identify TKAs at risk of failure. When the radiographic wear exceeded 1mm, there was a significantly increased probability of impending failure or need for revision

We compared the usefulness of radiography, CT and MRI in 25 children with spinal tuberculosis. Radiography provided most of the information necessary for diagnosis and treatment. Axial CT was the most accurate method for visualising the posterior bony elements. Sagittal MRI best showed the severity and content of extradural compression and helped to differentiate between an abscess and fibrous tissue. The main value of CT and MRI is in the preoperative evaluation of the small proportion of patients who require surgical treatment for paraplegia

A group of patients were studied 10 years after stopping work in a high-pressure environment. Radiographs of their long bones showed little change during the period, but only two of 12 scintigrams were normal. The 10 abnormal scintigrams contained 18 "hot-spots" which were not always associated with an abnormal radiographic appearance; the findings suggest that some lesions may never become visible on a radiograph. A reactive or repair process associated with these lesions may be prolonged and may not be beneficial, as structural failure of the joint may subsequently occur. Prognosis should therefore be guarded

Three-dimensional (3D) weight-bearing alignment of the lower extremity is crucial for understanding biomechanics of the normal and pathological functions at the hip, knee, and ankle joints. In addition, implant position with reference to bone is a critical factor affecting the long-term survival of artificial joints. The purpose of this study was to develop a biplanar system using a slot-scan radiography (SSR) for assessing weight-bearing alignment of the lower extremity and for assessing implant positioning with respect to bone. A SSR system (Sonial Vision Safire 17, Shimadzu, Kyoto, Japan) with a custom-made rotation table was used to capture x-ray images at 0 deg and 60 deg relative to the optical axis of an x-ray source [Fig.1]. The SSR system uses collimated fan beam x-rays synchronized with the movement of a flat-panel detector. This system allows to obtain a full length x-ray image of the body with reduced dose and small image distortion compared with conventional x-ray systems. Camera calibration was performed beforehand using an acrylic reference frame with 72 radiopaque markers to determine the 3D positions of the x-ray source and the image plane in the coordinate system embedded in the reference frame. Sawbone femur and tibia and femoral components of the Advance total knee system (Wright Medical Technology, Arlington, TN, USA) were used. Computed tomography of the sawbone femur and tibia was performed to allow the reconstruction of the 3D surface models. For the component, the computer aided design (CAD) model provided by the manufacturer was used. Local coordinate system of each surface model was defined based on central coordinates of 3 reference markers attached to each model. The sawbone femur and tibia were immobilized at extension, axial rotation, and varus deformity and were imaged using the biplanar SSR system. The 3D positions of the femur and tibia were recovered using an interactive 2D to 3D image registration method [Fig.2]. Then, the femoral component was installed to the sawbone femur. The 3D positions of the femur and femoral component were recovered using the above-mentioned image registration method. Overall, the largest estimation errors were 1.1 mm in translation and 0.9 deg in rotation for assessing the alignment, and within 1 mm in translation and 1 deg in rotation for assessing the implant position, demonstrating that this method has an adequate accuracy for the clinical usage

Summary Statement. The current study introduced the effects of projection errors on ankle morphological measurements using CT-based simulated radiographs by correlation analysis between 2D/3D dimensions and reliability analysis with randomised perturbations while measuring planar parameters on radiographs. Introduction. Clinical success of total ankle arthroplasty (TAA) depends heavily on the available anatomy-based information of the morphology for using implants of precisely matched sizes. Among the clinically available medical imaging modalities, bi-planar projective radiographs are commonly used for this purpose owing to their convenience, low cost, and low radiation dose compared with other modalities such as MRI or CT. However, the intrinsic articular surface of the ankle joint is not symmetrical and oblique which implies that it is difficult to describe all the anatomical dimensions in detail with only one radiograph, thereby hindering the determination of accurate ankle morphometric parameters. The purposes of this study were to compare the measurements of ankle morphology using 3D CT images with those on planar 2D images; and to quantify the repeatability of the 2D measurements under simulated random perturbations. Patients & Methods. Fifty-eight fresh frozen cadaveric ankle specimens were used in the current study. Each specimen was fixed in the neutral position with a plastic frame. After fixation, the specimen-fixation construct was scanned using a 16-slice spiral CT scanner (GE BrightSpeed 16, C&G Technologies, USA) with a slice thickness of 0.625 mm. A global coordinate system was embedded in the ankle specimen with the origin at the geometric center of the talus, the anteroposterior (A/P) axis in parallel to the base-plate, the superoinferior (S/I) axis perpendicular to the base-plate, and the mediolateral (M/L) axis as the line perpendicular to both the A/P and S/I axes. Fourteen 3D morphological parameters were automatically determined using a house-developed program in MATLAB R2010a (The MathWorks, Inc., USA). A simulated standard digital radiography system, in which the X-ray focus was 1 meter away from the image plane, was also introduced to determine the planar 2D morphological parameters for comparing with those determined in 3D. Reliability with randomised perturbations during measurements was also assessed in terms of the intra-class correlation coefficients using a 2-way mixed-effects average model (ICC3, k) for intra-examiner assessments. All statistical analysis was performed using SPSS 13.0 (SPSS Inc., USA). Results. Most of the morphological parameters had high correlation and reliability, except for the maximal tibial thickness (MTiTh), distance between most vertex of tibial mortise to the level of MTiTh (MDV) and radius of trochlea tali (TaR) had moderate to low correlation which were 0.54, 0.37 and 0.09 respectively. The ICC coefficients indicated that the MDV, talus width (TaW) and inclination angle between two most vertex points of trochlea tali (MLATa) had moderate and poor reliability which were 0.59, 0.49 and 0.07 respectively. Discussion/Conclusion. The current study introduced the effects of projection errors on ankle morphological measurements using CT-based simulated radiographs by correlation analysis between 2D/3D dimensions and reliability analysis with randomised perturbations while measuring planar parameters on radiographs. MTiTh and MDV are the important parameters to help surgeon pre-surgical decision-making. TaW is one of the critical parameters for choosing accurate sise of TAA implant. It implies that the respectively accurate pose of ankle is critical during bi-planar radiography

Purpose of study: The aim of this project was to ascertain whether tibio-femoral joint space width (JSW) measured both on Schuss and full extension radiographic views were predictive and accurate relative to the articular cartilage findings on arthroscopy. Methods & Results: The study was a prospective trial. The criterion for recruitment was knee pain indicative of arthritis that required arthroscopic assessment with a view to possible surgical management. Joint space narrowing (JSN) was assessed in the affected knee, in both the standing full extension and Schuss views. Joint arthroscopy was performed and each compartment area of the knee was calibrated and graded corresponding to the arthritic changes identified. In the 60 patients recruited, 61.7% were found to have grade 4 arthritic changes on knee arthroscopy. JSN in those with associated grade 4 changes on arthroscopy on either full extension or Schuss views was 75.7% and 78.4% respectively. However in 24.3% of those with grade 4 changes on arthroscopy no JSN was demonstrated on either full extension or Schuss views. Arthroscopic assessment of severe arthritic changes of the knee was significantly superior compared to the radiographic method (p< 0.05). Conclusions: The findings suggest that despite narrowed JSW measured on either radiographic view being indicative of severe articular cartilage loss, neither view accurately predicts articular cartilage loss in less advanced cases. In cases of grade 4 changes and no JSN the sites of articular cartilage loss corresponded to sites that are less likely to be accurately represented on either radiographic view. Our findings suggest that knee arthroscopy may be better suited to identifying smaller patches of cartilage loss whose surface area may not be sufficient to cause JSN but may still cause symptoms. We suggest knee arthroscopy is indicated in patients with knee pain suspicious of arthritis but who lack obvious JSN on either full extension or Schuss views. This enables micro-fracture techniques to be used with the aim of attenuating disease progression, and offers a thorough lavage that may also provide symptom relief

Abstract

Purpose: Despite the development of new imaging techniques (MRI, CT scan) longitudinal studies of total hip arthroplasty (THA) are still conducted with conventional radiographs. New techniques for conventional radiograpy such as luminous screens with memory raise the question of longitudinal study in patients with THA where the new screen-film might produce artefacts. Material and method: This prospective study examined intermethod and interobserver agreement. Thirty-seven patients were included in the series from July 1st, 1998 and September 30, 1998. Each patient had a double radiography series: three plain films using the conventional technique (C) and three digitalized screen films (D). The C were taken with a 1/1 ratio on a Philips Diagnost 90 table and developed using the Kodak M6 method using a 36 x 43 cm cassette for the pelvic x-ray and a 24 x 30 cm cassette for the x-ray of the prosthetic hip. The D were made on the Philips Diagnost 90 table and developed with the Agfa ADC70 procedure on a memory screen with a 5 pl/mm spatial resolution for 36 x 43 cm for the pelvic x-ray and 28 x 35 for the prosthetic hip. The same operator performed the complete radiography series in the same patient (C and D). The images were read examining the cement/bone interfaces and the prosthesis/cement interfaces looking for the classical radio-lucent lines in the De Lee and Charnley sectors. The presence and the thickness of the radiolucent line were classed in three groups: no line, line less than 2 mm, line greater than 2 mm. For each patient, the films were placed in anonymous folders and two subgroups were selected at random for the readers (a radiologist and an orthopaedic surgeon) who did not read successively the same films for the same patient. The results were recorded with an Excel data sheet and the statistical analysis was done with the BMDP software. Results: Thirty-seven patients were included (22 women and 15 men) with 40 THA. Mean age was 64 years (42–86). Mean follow-up of the THA was 25 months (2–248). Four patients had mechanical pain or deceased joint amplitude and 33 patients had no clinical sign. Only one lucent line was found measuring less than 2 mm in the 1st quadrant of the cup and the 3, 4, and 5 zones on the AP view and the 10, 11, 12 zones on the lateral view on the tail of the pros-thesis. In this study, the kappa value was less than 0.5 for the mean concordance according to the Landis and Koch classification. The Kappa was higher for the intermethod analysis irrespective of the reader, than for the interobserver analysis. Discussion, conclusion: Independent readers of the two types of images (C and D) did not demonstrate any difference for cemented or noncemented prosthesis in a longitudinal study of THA. The reproducibility between the C and D techniques was small. However, our study only analysed a few of the numerous radiographic signs considered to favour loosening (stress shielding, lucent lines etc.…). However, the analysis of the Kappa results demonstrated mean concordance between the techniques better than mean concordance between observers

Impaction bone grafting for the reconstitution of bone stock in revision hip surgery has been used for nearly 30 years. Between 1995 and 2001 we used this technique in acetabular reconstruction, in combination with a cemented component, in 304 hips in 292 patients revised for aseptic loosening. The only additional supports used were stainless steel meshes placed against the medial wall or laterally around the acetabular rim to contain the graft. All Paprosky grades of defect were included. Clinical and radiographic outcomes were collected in surviving patients at a minimum of ten years after the index operation. Mean follow-up was 12.4 years (. sd. 1.5) (10.0 to 16.0). Kaplan–Meier survival with revision for aseptic loosening as the endpoint was 85.9% (95% CI 81.0 to 90.8) at 13.5 years. Clinical scores for pain relief remained satisfactory, and there was no difference in clinical scores between cups that appeared stable and those that appeared radiologically loose. . Cite this article: Bone Joint J 2014;96-B:188–94

Introduction. Lisfranc joint injuries account for only 0.2% of all fractures but early diagnosis improves the chances of a better outcom]. Radiographic signs, such as diastasis (>2mm) of the 1–2 interspace, are subtle and. often missed, leading to a poorer outcome. We present a new radiographic sign, less likely to result in missed diagnoses. Null nypothesis: The intermetarsal angle remains unchanged in Lisfranc injuries. Method. A series of radiographs demonstrating Lisfranc injury were interspersed with normal and postoperative cases. Evidence of fixation was obscured. A selection of Foundation and Core Trainee medical staff measured the intermetatarsal angle (IMA) on two separate occasions. The measuring technique was demonstrated with no explanation for the reason behind the measurement. Results. The intra-class correlation (ICC) between observers was 0.96 and a mean 0.86 (range 0.69–0.96) for individual observers. IMA on comparative weight bearing AP views of injured and normal side, using Wilcoxon-signed rank test demonstrated a P< 0.0001 with mean values of 6.6 degrees (normal) versus 4.85 degrees (injured) and standard deviation of 1.97 & 1.91 degrees respectively. Conclusion. The high ICC value suggests that this radiographic sign is easily taught, reliable and reproducible. Analysis of individual angles suggests that there is a significant difference between the normal and pathological IMA. We therefore reject our null hypothesis. The data supports our proposition that that the IMA becomes more parallel in Lisfranc injuries and that this is an easily recognised sign, which could help reduce the incidence of missed injuries. Elucidation of the exact anatomical pathology responsible is the basis for further, anatomical, studies

Objective: The purpose of this study is to determine the accuracy of the push-pull radiographs in predicting the surgical correction in neuromuscular scoliosis. Study Design: Retrospective radiographic review. Subjects: Radiographs of 26 patients with neuromuscular scoliosis secondary to Duchennes Muscular Dystrophy were reviewed. All the patients had a posterior instrumented correction of the deformity by the same surgeon with the Universal Spinal System. Duchennes Muscular Dystrophy was chosen as a model for neuromuscular scoliosis since it represents a homogenous group with regards to the spinal deformity. Outcome measures: The Cobb angle, the translation of the apex of the deformity from the central sacral line, pelvic tilt and the number of motion segments in the curve were compared between pre-operative erect, push-pull view and the post-operative radiographs. Results were analysed using student’s t test for significance and Pearson’s coefficient for correlation with the SPSS software. Results: A correlation was seen in the form of an improvement in the Cobb angle, pelvic tilt and the apical translation when comparing the push-pull views and the post-operative radiographs. The improvement was statistically significant. Conclusion: The push-pull view provides an adequate assessment of the fl exibility that guides a safe deformity correction

A radiographic suvey has been carried out of 147 first-degree relatives of forty-seven patients treated in Edinburgh for spondylolisthesis of the fifth lumbar vertebra; twelve patients had the dysplastic (congenital) type and thirty-five an isthmic defect. The survey identified 19 per cent of relatives with spondylolysis, and index patients with each type of spondylolisthesis had relatives with the opposite type. Index patients with the dysplastic form had a higher proportion of affected relatives (33 per cent) than had those with the isthmic type (15 per cent), but both figures were significantly in excess of the estimated frequency for the general population of under 1 per cent and 5 per cent respectively. Spina bifida occulta at the fifth lumbar or first sacral level or both, and lumbosacral segmental defects were commoner amongst all individuals with spondylolysis than amongst unaffected relatives (dysplastic form 94 per cent, isthmic type 32 per cent, unaffected relatives 7 per cent). However, there was no single instance of a neural tube defect (anencephaly, spina bifida with or without meningocele, other generalised vertebral anomalies or spinal dysraphism) amongst 826 first-, second- or third-degree relatives. It is concluded that the developmental defects of the vertebrae associated with spondylolysis are not aetiologically related to the neural tube defects. The one in three risk of spondylolysis to near relatives of patients with the dysplastic form of spondylolisthesis is emphasised in order that the deformity in their sibs and children can be recognised at any early age

A method is described which provides standardised reproducible radiographic images of the lower limb. Anteroposterior and lateral radiographs are digitised and processed by computer to provide graphic/numeric displays of angles and linear measurements, relating the centre points of the hip, knee, and ankle. Two cases illustrate how surgical planning is facilitated when standardised data are available. These data confirm the close relationship between postoperative limb alignment and positioning of prosthetic elements

We recorded inter- and intra-observer variations in the classification of ankle fractures by the Lauge Hansen and Weber systems. Radiographs of 94 patients were classified independently by four observers. The observer variation was calculated by kappa statistics, which corrects the obtained values for the agreement expected by chance. There was an acceptable level of agreement for the overall classification into both systems. For the staging of supination-adduction and supination-eversion fractures in the Lauge Hansen system the agreement was poor. The results indicate that future classification systems should be subject to reliability analysis before they are accepted

Objective The hypothesis of this study is that the flexibility of idiopathic scoliosis curves as measured by traction radiography performed under general anaesthetic (TUA) will be superior to supine bending radiography. Subsequently, this may aid in determining the surgical approach, sparing patients anterior release surgery, and show greater correlation with the postoperative result. This is a new technique, not previously reported in the literature. Design A prospective comparison between TUA and supine bending radiography to determine curve flexibility, and examine their relationship with anterior release surgery and postoperative correction. Subjects This study was based on 21 patients with a diagnosis of idiopathic scoliosis, admitted for corrective surgery at our unit. Outcome measures The amount of correction achieved by each of the two methods on the preoperative curve was examined using a paired t-test. The influence of the TUA on the decision for anterior release surgery was noted, along with the correlation of each method with postoperative correction. Results On statistical analysis with a paired t-test, TUA showed significantly greater curve flexibility than that shown by supine bending radiographs (p< 0.001) irrespective of curve classification or magnitude. Of the 11 patients planned for anterior release surgery with posterior fusion, the use of TUA obviated this in 9 (82%) by demonstrating greater preoperative curve flexibility. Excluding thoracolumbar curves, TUA showed significantly greater postoperative correlation than supine bending radiography (R=0.79, R=0.61 respectively). Conclusion In our unit, traction radiography performed under general anaesthetic is superior to supine bending radiography in assessing curve mobility prior to surgery. Performing TUA has significant benefits to patients in avoiding unnecessary anterior release surgery, and has greater correlation with postoperative correction. In studying fulcrum bending radiographs, Cheung. 1. showed similar benefits in avoiding anterior release and we therefore recommend the use of these methods by other institutions

It is generally accepted that Hip-Knee-Ankle (long-leg) radiographs are a good measurement tool for biomechanical axis of the knee and they have been used as the outcome measure for many studies. Most of the surgeons recommend having pre operative and post operative long leg radiographs for total knee replacement surgery, although practice is not as common. We studied the biomechanical axis on long-leg films and compared it with computer navigation. The objectives were to find out repeatability of measurements of biomechanical axis with inter observer readings on long leg radiographs and to compare biomechanical axis measurements with Navigation values obtained during total knee replacement surgery. Our institution routinely uses long-leg radiographs for total knee replacement (TKR) surgery both pre- and post-operatively. A series of 209 patients who had navigated TKR between Jan 2007 and 2008 were selected. Stryker and Orthopilot systems for navigation were used. The intra-operative biomechanical axis measurements from the computer navigation files both pre-and post- implant were recorded. The long leg films were measured with a defined protocol from the digital images on PACS system. Centre of the head of femur was taken as the upper point. For the knee centre the midpoint of a line joining the distal femoral notch centre and upper tibia was used. For the ankle centre midpoint of the upper talar margin was used. An angle between the three points represented the radiological biomechanical axis. To investigate inter-observer error, two observers measured the pre- and post-operative biomechanical axis on long leg radiographs independently on 57 patients. For the inter-observer measurements on 57 patients, the intraclass correlation coefficient was 0.99 for pre-operative radiographs and 0.98 for post-operative radiographs. Maximum difference between the two observers was 2° in four cases. All other cases showed the same readings or 1° difference. There was a strong correlation, which was statistically significant, between the pre-operative radiographic and navigated measurements with Pearson correlation coefficient of 0.810 (p< 0.001). The maximum difference between the radiographic and navigated measurement was 24 degrees. The relationship between the postoperative measurements was weaker but statistically significant with Pearson correlation coefficient of 0.323 (p< 0.001). The maximum difference between the two methods of measurement was larger 15.5. It can be concluded from this study that biomechanical axis on a long leg radiograph is a repeatable measure with good inter-observer correlation. Although it is statistically significantly correlated with navigated readings, the absolute values may be different with both the methods. This raises the question on the reliability of long leg radiographs for the prediction of true biomechanical axis. Most of the larger value differences had a fixed flexion deformities (9 – 45 degrees). This can affect the readings on the long leg radiographs and make the deformity look either smaller or bigger. Also as our knee kinematic study has proven that the deformity does not remain the same in flexion as it was in extended knee that could also account for the difference in the readings. Other reasons for difference in the pre operative readings could be weight bearing status and surgical opening of the joint before taking the pre operative biomechanical axis measurements. Difference in the post operative readings could be attributed to weight bearing status, time length between navigation and radiographic measurements (6–12 wks), scarring of the soft tissues in the time and flexed posture of knee in the early post operative period

Eleven articulated scoliotic spines were examined radiographically and morphometrically. Measurement of the curve on anteroposterior radiographs of the specimens gave a mean Cobb angle of 70 degrees, though true anteroposterior radiographs of the deformity revealed a mean Cobb angle of 99 degrees (41% greater). Lateral radiographs gave the erroneous impression that there was a mean kyphosis of 41 degrees while true lateral projections revealed a mean apical lordosis of 14 degrees. Morphometric measurements confirmed the presence of a lordosis at bony level, the apical vertebral bodies being significantly taller anteriorly (P less than 0.02). There were significant correlations (P less than 0.01) between the true size of the lateral scoliosis, the amount of axial rotation and the size of the apical lordosis. This study illustrates the three-dimensional nature of the deformity in scoliosis and its property of changing in character and magnitude according to the plane of radiographic projection

It is generally accepted that Hip-Knee-Ankle (long-leg) radiographs are a good measurement tool for biomechanical axis of the knee and they have been used as the outcome measure for many studies. Most of the surgeons recommend having pre operative and post operative long leg radiographs for total knee replacement surgery, although practice is not as common. We studied the biomechanical axis on long-leg films and compared it with computer navigation. The aims were. To find out repeatability of measurements of biomechanical axis with inter observer readings on long leg radiographs. To compare X-ray biomechanical axis measurements with Navigation values obtained during total knee replacement surgery. Our institution routinely uses long-leg radiographs for total knee replacement (TKR) surgery both pre- and postoperatively. A series of 209 patients who had navigated TKR between Jan 2007 and 2008 were selected. Stryker and Orthopilot systems for navigation were used. The intra-operative biomechanical axis measurements from the computer navigation files both pre-and post- implant were recorded. The long leg films were measured with a defined protocol from the digital images on PACS system. Centre of the head of femur was taken as the upper point. For the knee centre the midpoint of a line joining the distal femoral notch centre and upper tibia was used. For the ankle centre midpoint of the upper talar margin was used. An angle between the three points represented the radiological biomechanical axis. To investigate inter-observer error, two observers measured the pre- and postoperative biomechanical axis on long leg radiographs independently on 57 patients. For the inter-observer measurements on 57 patients, the intraclass correlation coefficient was 0.99 for pre-operative radiographs and 0.98 for post-operative radiographs. Maximum difference between the two observers was 2° in four cases. All other cases showed the same readings or 1° difference. There was a strong correlation, which was statistically significant, between the pre-operative radiographic and navigated measurements with Pearson correlation coefficient of 0.810 (p< 0.001). The maximum difference between the radiographic and navigated measurement was 24 degrees. The relationship between the post-operative measurements was weaker but statistically significant with Pearson correlation coefficient of 0.323 (p< 0.001). The maximum difference between the two methods of measurement was larger 15.5. It can be concluded from this study that biomechanical axis on a long leg radiograph is a repeatable measure with good inter-observer correlation. Although it is statistically significantly correlated with navigated readings, the absolute values may be different with each method. This raises the question of the reliability of long leg radiographs for the prediction of true biomechanical axis. Most of the larger value differences had a fixed flexion deformities (9 – 45 degrees). This can affect the readings on the long leg radiographs and make the deformity look either smaller or bigger. Also, our knee kinematic study has proven that the deformity does not remain the same in flexion and in the extended knee. This could also account for the difference in the readings. Other possible reasons for differences in the pre operative readings: the weight bearing status and the surgical opening of the joint, before taking the pre operative biomechanical axis measurements. Differences in the post operative readings could be attributed to: weight bearing status, time length between navigation and radiographic measurements (6–12 wks), scarring of the soft tissues in the meantime and flexed posture of knee in the early post operative period

Introduction

A comprehensive understanding of pelvic orientation prior to total hip arthroplasty is necessary to allow proper cup positioning and mitigate the risks of complications associated with component malpositioning. Measurements using anteroposterior (AP) radiographs have been described as effective means of accurately predicting pelvic orientation. The purpose of our study was to describe the inter- and intra-observer reliability and predictive accuracy of predicting pelvic tilt using AP radiographs.

To assess the effect of improved methods of femoral cementing on the loosening rates in young patients, we reviewed 50 'second-generation' cemented hip arthroplasties in 44 patients aged 50 years or less. The femoral stems were all collared and rectangular in cross-section with rounded corners. The cement was delivered by a gun into a medullary canal occluded distally with a cement plug. A clinical and radiographic review was undertaken at an average of 12 years (10 to 14.8) and no patient was lost to follow-up. No femoral component was revised for aseptic loosening, and only one stem was definitely loose by radiographic criteria. By contrast, 11 patients had undergone revision for symptomatic aseptic loosening of the acetabular component and 11 more had radiographic signs of acetabular loosening

A computerised image analyser has been used experimentally to determine its possible usefulness in quantifying bone density. Rats were prepared for this purpose and ash weight/volume readings were obtained on femora which had been radiographed and studied to estimate radiographic density by means of the image analyser. The findings indicated that rats can be prepared by administering oestradiol or by allowing an additional week's growth, both of which give a statistically significant increase of bone density. The computerised image analyser was able to detect these differences but the correlations, although real and linear, between ash weight/volume and radiographic density were not large. Further refinements in techniques will be needed before the system is applied clinically

We report two new radiographic projections for evaluating avulsion fractures at the lateral malleolus. We used seven freshly amputated legs with simulated avulsion fractures and radiopaque markers to assess their value. The projections allow accurate assessment of the displacement of fragments without superimposition, and also show whether they affect the anterior talofibular or the calcaneofibular ligament or both

To assess the accuracy of plain digitised radiographic images for measurement of neck-shaft and stem-shaft angles in hip resurfacing arthroplasty. Fifteen patients having undergone hip resurfacing arthroplasty with the Birmingham Hip Resurfacing (BHR) were selected at random. Digital radiographs were analyzed by three observers. Each observer measured the femoral neck-shaft angles (NSA) of the pre-operative and stem-shaft angles (SSA) of the postoperative radiographs on two separate occasions spanning one week. The effect of femur position on SSA measured by digital radiographs was also analyzed. A BHR prosthesis was cemented into a third generation Sawbone composite femur. Radiographs were taken with the synthetic specimen positioned in varying angles of both flexion and external rotation in increments of 10° ranging from 0° to 90°. The mean intraobserver difference in measured angle was 3.13° (SD 2.37°, 95% CI +/−4.64°) for the NSA group and 1.49° (SD 2.28°, 95% CI +/−4.47°) for the SSA group. The intraclass correlation coefficient for the NSA group was 0.616 and for the SSA group was 0.855. Flexion of the synthetic femur of twenty degrees resulted in a five degree discrepancy in measured SSA and flexion of forty degrees resulted in a thirteen degree discrepancy. External rotation of the synthetic specimen of twenty and forty degrees resulted in a three and nine degree discrepancy in measured SSA, respectively. Patient malposition during radiographic imaging can contribute to erroneous NSA and SSA results. Significant intra- and inter-observer variation was noted in the measurement of neck shaft angle however, variation was less marked for measurement of stem shaft angle

We present the results of prospective evaluation of digital compared to plain radiographic pre-operative templating for primary total knee replacement. All consecutive patients undergoing primary knee replacement under the senior author (AS) were eligible. Patients with previous knee replacement or without calibrated digital or plain radiographs were excluded. Plain radiographs were templated against acetate templates supplied by the manufacturer. Digital images were templated with the help of commercial software TraumaCad. A 25mm spherical metal ball placed nearest to the affected knee joint acted as calibration object. AS performed all the templating. The ICC value for intra-rater reliability was 0.846 for tibial templating and 0.840 for femoral templating. PFC sigma cruciate substituting components were implanted in all patients. 28 consecutive patients between April 2006 and June 2007 were included. Accurate digital templating score was 80% for tibial implant and 40% for femur. Accuracy of analog templating was 55% for tibial implant and 50% for femur. There was no mismatch of over one size. The differences between templated and implanted sizes were plotted against their mean in Bland-Altman plot. The 95% confidence interval of the differences between digital and actual sizes were: 0.78 to − 0.75 sizes for tibial implant and 1.15 to −0.93 sizes for femoral implant. The 95% confidence interval of the differences between plain and actual sizes were: 0.38 to −0.99 size for tibial implant and 0.93 to −1.32 size for femoral implant. The two tailed P value for difference between digital and analog templating from a Wilcoxon matched pair signed rank test was 0.021 for tibia and 0.006 for femur. We found preoperative templating by the operating surgeon reliable and accurate but digital templating did not offer any additional advantage

Introduction: The most widely accepted method for measuring bone mineral density (BMD) is Dual-energy X-ray Absorptionmetry (DXA). However, the need for relatively expensive equipment and trained personnel lower the accessibility of DXA as a routine screening tool. Plain pelvic X-ray radiography is a simple and inexpensive examination. In principal, the gray level of the bone in the X-ray radiograph is related to BMD. However, several factors render plain X-ray radiographs of the hip unsuitable for BMD measurements, mainly the variability in X-ray exposure levels and the soft tissue surrounding the bone. In this study, we aimed to develop new modifications of plain X-ray radiography of the proximal femur. Patients and methods: The study population consisted of 18 women with an average age of 77 years (range 57–96 years) who were hospitalized due to a low-energy fracture of the neck of the femur. Each patient’s contralateral hip was radiographed with an aluminium step-wedge positioned near the hip as a standard reference, using a computerized radiography system. A DXA examination of the same hip followed the plain radiograph. On each radiograph, regions of interest (ROI) were determined in concordance with the ROI of the DXA examination. The mean gray level was measured for each ROI. The neck-shaft angle and the femoral head diameter were also measured. Results: Comparing the gray levels of the plain radiograph with the BMD levels obtained by the DXA revealed a coefficient ratio of R=0.499. Correction of the gray levels using the step wedge as a standard reference revealed a ratio of R=0.576. If further correction was made with measurement of the soft tissue gray levels, a ratio of R=0.708 was obtained. Using the anatomical measurements (neck-shaft angle and femoral head diameter), a ratio of R=0.948 was obtained. Conclusion: This study shows that a plain digital radiograph of the pelvis can provide valuable information concerning the bone mineral content of the proximal femur, which is comparable to the results of the DXA examination. Ultimately, the research can lead to the development of a fast, available and relatively inexpensive technique to diagnose osteoporosis

Purpose: The Instability Severity Index Score (ISIS) is a 6-item questionnaire that has been reported to predict failure of arthroscopic Bankart repair among patients treated for recurrent anterior glenohumeral instability. Two of the ISIS items pertain to radiographic features (presence of a Hill-Sachs lesion, loss of glenoid contour). These, however have yet to be validated. The goal of this study was to examine the inter – and intra-rater agreement and corresponding reliability of the radiographic aspects of the ISIS. Method: Fifty-two plain, randomly selected, true antero-posterior radiographs in 45° gleno-humeral external rotation were evaluated by five assessors (three upper extremity orthopaedic surgeons, one senior orthopaedic resident and one musculoskeletal radiologist). Radiographs were retrieved for patients with documented recurrent shoulder instability requiring surgical stabilization and placed in a blinded Microsoft Powerpoint presentation for evaluation. Assessors were asked to determine the presence/absence of a Hill-Sachs lesion and if a loss of glenoid contour was present. Radiographs were evaluated in random order on two occasions, separated by a one-week time interval. Intra – and inter-rater reliability was assessed using percentage of agreement and kappa statistics. Results: For session one, the number of Hill-Sachs lesions observed among raters ranged from 11 to 32. This resulted in inter-rater agreement ranging from 48% to 78% (k = 0.07 to 0.42), indicating poor to fair reliability. Cases with loss of glenoid contour ranged from seven to 14 with inter-rater agreement of 66% and 90% (k = 0.01 to 0.61), suggesting poor to moderate reliability. Session two led to modest increases in inter-rater agreement. The number of Hill-Sachs lesions observed ranged from four to 30 (agreement of 48% to 84%; k = 0.11 to 0.60) indicating fair to moderate reliability and the number of cases with loss of glenoid contour ranged from three to 14 (agreement of 66% to 94%; k = – 0.04 to 0.69), ranging from poor to moderate reliability. With respect to intra-rater reliability, agreement ranged from 71% to 94% (k = 0.41 to 0.86) for Hill-Sachs lesions, indicating fair to good reliability and 76% to 94% (k= 0.20 to 0.74) for loss of glenoid contour, ranging from fair to good reliability. Intra-rater agreement and corresponding kappa values were highest among the upper extremity surgeons and the musculoskeletal radiologist, particularly for loss of glenoid contour (85% to 94%; k = 0.56 to 0.74) suggesting there is moderate to good reliability in this measurement. Conclusion: Our results indicate that the intra-rater reliability of the ISIS radiographic features was highest among upper extremity specialists and the musculoskeletal radiologist, suggesting that the ISIS may have utility in an experienced clinician’s individual practice. As the inter-rater reliability appears low, particularly for Hill-Sachs lesions, its wide-spread use across surgeons should be examined in further research