Anteroposterior Images Research Articles

Using the Anatomical Axis as an Alternative to the Mechanical Axis to Assess Knee Alignment

The treatment of knee osteoarthritis and the preparation for total knee arthroplasty require repetitive imaging to guide preoperative planning and operative technique. Full-length standing anteroposterior images are the gold standard in assessing the alignment of the limb via the measurement of the mechanical axis of the knee. The anatomical axis can be obtained from a more limited image of the knee, and as such is less expensive and exposes the patient to less ionizing radiation. The objective of this cross-sectional prospective study was to examine the extent to which the anatomical axis measured on a fixed-flexed posteroanterior (Rosenberg view) radiograph correlates with the mechanical axis. The data of 209 total knee arthroplasty radiographs were analyzed to compare the preoperative correlation between the mechanical and anatomical axis. The anatomical axis correlated with the mechanical axis when it was measured from both the standing full-length anteroposterior radiograph and from a fixed-flexed posteroanterior radiograph. Using an angle of offset found from linear regression, these correlations become closer. Body mass index and Kellgren-Lawrence grade were not found to have a significant effect. It is the conclusion of this study that the anatomical axis, as measured from a limited knee radiography, may serve as a plausible estimate of the mechanical axis when done with a neutral angle of offset, and that offset angle depends on gender and the imaging technique used to determine the anatomical axis.

Minimally invasive plate osteosynthesis for midshaft clavicular fractures using superior anatomic plating

The minimally invasive plate osteosynthesis procedure has been widely applied for long-bone fixations; however, this technique is not commonly used for clavicular midshaft fractures. In this study, we introduced this technique for midshaft clavicular fractures using superior anatomic locking plates and evaluated its clinical and radiographic outcomes. From June 2013 to July 2014, 15 patients with acute midshaft clavicular fractures were treated with the minimally invasive plate osteosynthesis technique using a 3.5-mm clavicular superior anatomic locking plate. Anteroposterior plain X-ray images of the clavicle were taken at 4-week intervals until union was observed. The last clinical follow-up assessments were performed postoperatively at a mean of 16.54 months (range, 10-23 months). In addition, for clinical evaluations, the Constant score and the Disability of the Arm, Shoulder and Hand score were assessed. The average operative time was 60.2 ± 20.1 minutes (range, 40-80 minutes), with blood loss of 25 ± 5 mL (range, 20-30 mL) during the operation. The mean union time for the patients was 10.1 ± 1.4 weeks (range, 8-12 weeks), and no delayed union or nonunion was observed. There were no major complications, including infections, plate breakages, or neurovascular injuries. No skin irritation was observed, and only 2 patients felt local incision numbness. All patients obtained satisfactory shoulder functions. The mean Constant score was 99 ± 1.8 (range, 95-100), and the mean Disability of the Arm, Shoulder and Hand score was 3.8 ± 2.9 (range, 0-10) at the last control visit. The minimally invasive plate osteosynthesis procedure that was introduced in this study for midshaft clavicular fractures with superior anatomic locking plate is a reproducible procedure and an alternative to conventional operative methods.

EFFICACY OF AN EXTRAVASCULAR LUNG WATER DRIVEN NEGATIVE FLUID BALANCE PROTOCOL

The study and monitoring of facial appearance is particularly important in the field of orthodontics and reconstructive maxillo-facial surgery. The introduction of new medical imaging techniques, such as X-ray computerized tomography (CT), has enabled surgery to be planned in three dimensions, compared with conventional methods using lateral and antero-posterior cephalographic images. Whilst it is possible to visualize bone and soft tissue structure the repeated use of CT scanning is undesirable because of the high doses of radiation involved. The research involves the development of a simple, low cost and non-invasive three-dimensional scanning method for facial surfaces. This is achieved using a technique known as structured light, using a standard commercial slide projector, CCD cameras and a framestore linked to a PC. The eventual aim is to provide clinicians a software assisted surgical procedure, by merging X-ray and skin data, allowing the manipulation of bone and soft tissue. This will give the facility to predict and monitor post-surgical appearance, detailing the effects of surgery benefiting both the clinician and patient. The research focuses on how the images are obtained using the scanning system and the subsequent image processing of data to give a realistic 3D image using a standard PC.

Loss of offset after pertrochanteric hip fractures affects hip function one year after surgery with a short intramedullary nail. A prospective cohort study.

We hypothesised that protruding collum screws in intramedullary nails used for pertrochanteric fractures cause lateral pain/discomfort and that loss of offset relates to poorer hip function. Seventy-six patients with an acute pertrochanteric femoral fracture AO types A1 and A2 were operated upon using a short intramedullary nail and were included in a prospective observational cohort study and followed-up for one year. The main outcome variables were lateral pain and hip function as evaluated with the Harris Hip Score. The main exposure was compression along the collum screw and lateral protrusion measured by anteroposterior X-ray images. Perioperative images were compared to images at the follow-up visit. Outcome variables were adjusted in regression models for reduction, fracture type, body mass index, sex and age. A total of 28 (36 %) patients experienced lateral pain at one year. We found a correlation between lateral protrusion and lateral pain, adjusted OR 4.5 per protruding centimetre (95 % CI, 1.1-17.5). Collum compression correlated with a poorer outcome with Harris Hip Score -14.2 per compressed centimetre (95 % CI, -21.8 to -6.7). In patients with type A1 and A2 pertrochanteric fractures operated on using intramedullary nailing, a large compression and lateral protrusion of the collum screw are associated with poorer hip function and lateral pain. New technical improvements for implants should focus on these factors to improve functional outcome after surgery.

Concordance in the radiological diagnosis of thoracolumbar spine fractures

IntroductionThoracolumbar spine fractures are frequent and severe. Early diagnosis and appropriate treatment to obtain good clinical results is essential, with many classifications being proposed for this purpose. ObjectiveTo determine the external validity of radiographic and computed tomography (CT) measurements for the most used classifications, and decide on the type of treatment required. The working hypothesis is the existence of external validity of radiographic measurements. Material and methodA sample of patients with thoracolumbar fracture was selected. Three spine specialists and a resident performed measurements on anteroposterior and lateral radiographic images as well as coronal, sagittal and axial CT slices. Fractures were classified as stable or unstable, evaluating the degree of intra-and interobserver agreement based on a standard observer. Sagittal index of Farcy, lateral wedging, Beck Index, traumatic regional angulation and channel occupancy were studied. ResultsAll indicators studied, except the lateral wedging, showed a high degree of concordance. ConclusionsInstability determinants studied with radiographs and CT, which had obtained statistical significance, are reliable and accurate for the classification of thoracolumbar fractures and, therefore, to indicate an appropriate treatment.

SYNDROME IN QUESTION

The Iso-Kikuchi Syndrome is a rare condition characterized by nail dysplasia involving the index fingers, including micronychia, polyonychia, anonychia, irregular lunula, malalignment and hemionychogryphosis. On the antero-posterior image, radiologic examination reveals a narrowing of the distal phalanx. The lateral image shows a Y-shaped bifurcation of the distal phalanx. We report a case of a patient with typical clinical and radiologic signs of Iso-Kikuchi Syndrome.

Cumulative Radiation Exposure With EOS Imaging Compared With Standard Spine Radiographs

Study DesignRetrospective comparative study. ObjectivesThis study sought to estimate the total radiation exposure to scoliosis patients during the entire treatment course using standard imaging techniques versus EOS posteroanterior (PA) and anteroposterior (AP) views. Summary of Background DataEOS is a slot-scanning X-ray system designed to reduce radiation exposure in orthopedic imaging. There are few independent studies comparing organ and total effective radiation dose from standard EOS PA, AP, and lateral imaging versus conventional projection radiographs for children with spinal deformity. MethodsA total of 42 skeletally immature idiopathic scoliosis patients were treated with bracing (21) or spinal fusion (21) and were followed to skeletal maturity. The number of scoliosis radiographs (PA and lateral) for each patient was recorded. A computerized dosing model was used to calculate estimated patient and organ doses for PA and lateral scoliosis X-rays taken with EOS or computed radiography with a filter (CR) or without a filter (CRF). Assuming that each X-ray taken delivered the same radiation as the phantom calculation, the authors estimated the total effective and organ dose that each adolescent would have received using EOS, CR, or CRF. Annual background radiation is 3 mSv. ResultsMean number of radiographs per patient was 20.9 (range, 8–43). Patients who underwent surgical treatment had a significantly greater number of X-rays than those who were braced (27.3 vs. 14.5; p < .001). Assuming all films were CR, the mean cumulative dose was estimated at 5.38 mSv. With standard EOS films, the mean cumulative estimated dose was 2.66 mSv, a decrease of 50.6%. An AP versus PA EOS radiograph resulted in an 8 times higher radiation dose to the breasts and 4 times higher dose to the thyroid. ConclusionsThe standard EOS imaging system moderately reduced the total radiation exposure to skeletally immature scoliosis patients. Over the entire treatment course, this represented 2.72 mSv mean reduction or 0.91 years of background radiation. Posteroanterior films significantly reduced breast and thyroid dose.

Radiology’sLegacy: Rummaging through the Attic

Early articles in Radiology are based on conventional radiography and provide the foundation for both the way we think about extracting diagnostically important information from images and the spectacular technologic achievements in the decades that followed; therefore, we decided to include in this issue of Radiology a pictorial essay of select figures and our thoughts on the articles themselves to give a taste of the beginnings of so many of our current imaging and research activities.

Contrast enhanced computed tomography and reconstruction of hepatic vascular system for transjugular intrahepatic portal systemic shunt puncture path planning.

To describe a method for the transjugular intrahepatic portal systemic shunt (TIPS) placement performed with the aid of contrast-enhanced computed tomography (CECT) and three-dimensional reconstructed vascular images (3D RVIs), and to assess its safety and effectiveness. Four hundred and ninety patients were treated with TIPS between January 2005 and December 2012. All patients underwent liver CECT and reconstruction of 3D RVIs of the right hepatic vein to portal vein (PV) prior to the operation. The 3D RVIs were carefully reviewed to plan the puncture path from the start to target points for needle pass through the PV in the TIPS procedure. The improved TIPS procedure was successful in 483 (98.6%) of the 490 patients. The number of punctures attempted was one in 294 (60%) patients, 2 to 3 in 147 (30%) patients, 4 to 6 in 25 (5.1%) patients and more than 6 in 17 (3.5%) patients. Seven patients failed. Of the 490 patients, 12 had punctures into the artery, 15 into the bile duct, eight into the gallbladder, and 18 through the liver capsule. Analysis of the portograms from the 483 successful cases indicated that the puncture points were all located distally to the PV bifurcation on anteroposterior images, while the points were located proximally to the bifurcation in the three cases with intraabdominal bleeding. The complications included three cases of bleeding, of whom one died and two needed surgery. Use of CECT and 3D RVIs to plan the puncture path for TIPS procedure is safe, simple and effective for clinical use.

Comparative Analysis of Shoulder Balance through Growth Guidance Techniques in the Surgical Treatment of Early-onset Scoliosis

Objective: The purpose of this study was to compare the efficacy of growth guidance techniques (single and dual growing rods, Vertical Expandable Prosthetic Titanium Rod-VEPTR) on shoulder balance, in the surgical treatment of early-onset scoliosis. Methods: Thirty six patients with early-onset scoliosis (EOS) due to various etiologies who were operated on in two different institutions were included in the study and they were divided in 3 groups. Group 1 consisted of 11 patients (mean age 7.5 years) who were treated with a single growing rod, Group 2 had 13 patients (mean age 8.1 years) who were treated with dual growing rods, and Group 3 consisted of 12 patients (mean age 4.1 years) who were treated with VEPTR technique. The coracoid height difference (CHD), clavicular tilt angle difference (CTAD) and clavicula-rib cage intersection difference (CRID) were measured on standing anteroposterior X-ray images in the preoperative, early postoperative and the last follow-up periods. Data obtained from these measurements were subject to statistical analysis. Results: The average postoperative follow up period was 3.04 (range: 2.3 to 4.8) years for Group 1, 2.23 (range: 1 to 3.1) years for Group 2 and 2.18 (range: 1 to 3.2) years for Group 3. Clinical improvement in shoulder balance was obtained for Group 1 and Group 2 post-operatively, but there was no significance in the comparison among the three groups. Conclusion: The effect of growth guidance techniques on shoulder balance remains unpredictable in the surgical treatment of early-onset scoliosis.

A comparison of the effects of two different techniques on shoulder balance in the treatment of congenital scoliosis: Vertical expandable prosthetic titanium rib and dual growing rod.

Purpose:The purpose of this study is to compare the effects of two different growth guidance techniques (dual growing rod and vertical expandable prosthetic titanium rib [VEPTR]) on shoulder balance, in the surgical treatment of congenital scoliosis.Materials and Methods:Thirteen patients who were operated due to congenital scoliosis are divided into two groups. The coracoid height difference and clavicular tilt angle difference were measured on standing anteroposterior X-ray images in the preoperative, early postoperative periods, and during the last follow-up.Results:Clinical improvement in shoulder balance was obtained in VEPTR during the last follow-up, but there was no significance in the comparison among the two groups during the last follow-up.Conclusion:The effect of the growth guidance techniques on shoulder balance positively contributes in the surgical treatment of congenital scoliosis.

Bone Marrow Transplantation Followed by Growth Factors Injection in a Patient with Femoral Neck Nonunion: A Case Report

Background: Most fractures of femoral neck typically heal, but a significant proportion of fractures fail to heal, resulting in aseptic bone necrosis, delayed union or persistent nonunion. Specially, nonunion of fractured neck of femur in young adults is a serious problem. Some preclinical evidences show the therapeutic potential of autologous bone marrow for bone fracture healing; however, clinical outcome following of transplantation of bone marrow cells in patients with femoral neck nonunion has never been reported. Case description: We describe a 57-year-old male who had a femoral neck nonunion and received autologous bone marrow transplantation, followed by growth factors injection. The primary endpoint of this study is to achieve radiological fracture healing (union) by evaluating anteroposterior images taken after and on 6th month, following bone marrow therapy and no serious adverse event occurred. Literature review: To our knowledge, this is the first case in the literature of nonunion of femoral neck fracture treated with percutaneous autologous bone marrow transplantation. Clinical relevance: This case suggests that autologous bone marrow transplantation, followed by plasma rich in growth factors (PRGF) could be considered as an exciting option to treat nonunion in femoral neck fracture.

Installation of a Neuromate Robot for Stereotactic Surgery: Efforts to Conform to Japanese Specifications and an Approach for Clinical Use-Technical Notes.

The neuromate is a commercially available, image-guided robotic system for use in stereotactic surgery and is employed in Europe and North America. In June 2015, this device was approved in accordance with the Pharmaceutical Affairs Law in Japan. The neuromate can be specified to a wide range of stereotactic procedures in Japan. The stereotactic X-ray system, developed by a Japanese manufacturer, is normally attached to the operating table that provides lateral and anteroposterior images to verify the positions of the recording electrodes. The neuromate is designed to be used with the patient in the supine position on a flat operating table. In Japan, deep brain stimulation surgery is widely performed with the patient's head positioned upward so as to minimize cerebrospinal fluid leakage. The robot base where the patient's head is fixed has an adaptation for a tilted head position (by 25 degrees) to accommodate the operating table at proper angle to hold the patient's upper body. After these modifications, the accuracy of neuromate localization was examined on a computed tomography phantom preparation, showing that the root mean square error was 0.12 ± 0.10 mm. In our hospital, robotic surgeries, such as those using the Da Vinci system or neuromate, require operative guidelines directed by the Medical Risk Management Office and Biomedical Research and Innovation Office. These guidelines include directions for use, procedural manuals, and training courses.

The effect of peroneus brevis tendon anatomy on the stability of fractures at the fifth metatarsal base.

Nonunion of classic Jones fractures has typically been attributed to the precarious vascular anatomy of the proximal fifth metatarsal. Despite this theory, the operative treatment of these fractures utilizes biomechanical solutions. The purpose of the present study was to evaluate the influence of the peroneus brevis (PB) tendon on the stability of fractures of the proximal fifth metatarsal. We utilized 5 matched pairs (10 specimens) of fresh-frozen cadaveric specimens. We used 2 loading conditions: (1) a simulated fracture distal to the PB insertion (Jones equivalent) and (2) a simulated fracture within the footprint of the PB insertion (avulsion equivalent). Following the creation of the fracture, each lower extremity was statically loaded through the Achilles and PB tendons. Our primary outcome measure was the degree of fracture diastasis with loading of the PB. Anteroposterior images with and without loading were obtained to evaluate fracture separation. We utilized a paired Student t test and the intraclass correlation coefficient (ICC) for all statistical analyses. The average length of the PB footprint was 15.2 mm. The simulated Jones fractures demonstrated greater fracture widening following loading of the PB tendon compared to the simulated avulsion fractures. The simulated avulsion fractures widened 0.4 mm on loading compared to 1.1 mm of widening in the simulated Jones fractures (P = .02). Intraobserver reliability for all radiographic measurements showed substantial agreement (ICC = 0.91). The PB exerted a deforming force on the proximal fragment of simulated Jones fractures. This deforming force was less pronounced in the simulated avulsion fractures. The principal findings of this study were that proximal fifth metatarsal fractures distal to the PB insertion were significantly more unstable than more proximal fractures. Our findings help support the notion that a mechanical component may contribute to the poor healing potential of Jones fractures secondary to deformation exerted by the PB tendon.

Offset and anteversion reconstruction after cemented and uncemented total hip arthroplasty: an evaluation with the low-dose EOS system comparing two- and three-dimensional imaging.

Accurate evaluation of femoral offset is difficult with conventional anteroposterior (AP) X-rays. The EOS imaging system is a system that makes the acquisition of simultaneous and orthogonal AP and lateral images of the patient in the standing position possible. These two-dimensional (2D) images are equivalent to standard plane X-rays. Three-dimensional (3D) reconstructions are obtained from these paired images according to a validated protocol. This prospective study explores the value of the EOS imaging system for comparing measurements of femoral offset from these 2D images and the 3D reconstructions. We included 110 patients with unilateral total hip arthroplasty (THA). The 2D offset was measured on the AP view with the same protocol as for standard X-rays. The 3D offset was calculated from the reconstructions based on the orthogonal AP and lateral views. Reproducibility and repeatability studies were conducted for each measurement. We compared the 2D and 3D offset for both hips (with and without THA). For the global series (110 hips with and 110 without THA), 2D offset was 40 mm (SD 7.3; 7-57 mm). The standard deviation was 6.5 mm for repeatability and 7.5 mm for reproducibility. Three-dimensional offset was 43 mm (SD 6.6; 22-62 mm), with a standard deviation of 4.6 for repeatability and 5.5 for reproducibility. Two-dimensional offset for the hips without THA was 40 mm (SD 7.0; 26-56 mm), and 3D offset 43 mm (SD 6.6; 28-62 mm). For THA side, 2D offset was 41 mm (SD 8.2; 7-57 mm) and 3D offset 45 mm (SD 4.8; 22-61 mm). Comparison of the two protocols shows a significant difference between the 2D and 3D measurements, with the 3D offset having higher values. Comparison of the side with and without surgery for each case showed a 5-mm deficit for the offset in 35 % of the patients according to the 2D measurement but in only 26 % according to the 3D calculation. This study points out the limitations of 2D measurements of femoral offset on standard plane X-rays. The reliability of the EOS 3D models has been previously demonstrated with CT scan reconstructions as a reference. The EOS imaging system could be an option for obtaining accurate and reliable offset measurements while significantly limiting the patient's exposure to radiation.

Trabecular bone score in female patients with systemic sclerosis: comparison with rheumatoid arthritis and influence of glucocorticoid exposure.

Systemic sclerosis (SSc) is associated with an increased risk of osteoporosis and fractures. To date, the etiology of bone loss in SSc is unclear. Trabecular bone score (TBS) provides an indirect measurement of bone microarchitecture, independent of areal bone mineral density (aBMD). The aims were to assess bone involvement in SSc using TBS in comparison with a "high-risk" population with rheumatoid arthritis (RA) and controls, and to investigate the determinants of a low TBS. This was a cross-sectional study of 65 women with SSc, 138 age-matched female patients with RA, and 227 age-matched female controls. Spine and hip aBMD were assessed using dual-energy X-ray absorptiometry. TBS was calculated from the anteroposterior image of the spine aBMD. TBS was significantly lower in SSc compared to controls (p < 0.0001) and did not differ from RA (p = 0.128), despite lower cumulative and daily glucocorticoid (GC) dose (p < 0.0001). Further, patients with SSc receiving GC ≥ 5 mg/day had a significantly lower TBS than those receiving GC < 5 mg/day (p = 0.001). Multivariate analysis revealed that a low TBS was independently associated with daily GC dose (OR 5.6, 95% CI 1.7-19.2) and a T score ≤ -2.5 SD (OR 5.0, 95% CI 1.5-7.0) in SSc. No association between GC and TBS was found in RA. Our results support the development of a combined approach using both TBS and aBMD for the assessment of bone microarchitecture in inflammatory rheumatic diseases. Our study showed that SSc-related bone involvement is characterized by an impairment in bone quality in addition to reduced bone quantity, and highlights that TBS can identify the negative effect of GC on bone microarchitecture.

Concordancia en el diagnóstico radiológico de las fracturas del raquis toracolumbar

IntroductionThoracolumbar spine fractures are frequent and severe. Early diagnosis and appropriate treatment to obtain good clinical results is essential, with many classifications being proposed for this purpose. ObjectiveTo determine the external validity of radiographic and computed tomography (CT) measurements for the most used classifications, and decide on the type of treatment required. The working hypothesis is the existence of external validity of radiographic measurements. Material and methodA sample of patients with thoracolumbar fracture was selected. Three spine specialists and a resident performed measurements on anteroposterior and lateral radiographic images as well as coronal, sagittal and axial CT slices. Fractures were classified as stable or unstable, evaluating the degree of intra-and interobserver agreement based on a standard observer. Sagittal index of Farcy, lateral wedging, Beck Index, traumatic regional angulation and channel occupancy were studied. ResultsAll indicators studied, except the lateral wedging, showed a high degree of concordance. ConclusionsInstability determinants studied with radiographs and CT, which had obtained statistical significance, are reliable and accurate for the classification of thoracolumbar fractures and, therefore, to indicate an appropriate treatment.

Complication Avoidance and Management Using the O-arm for Odontoid Screw Fixation: Technical Note

Objectives: Odontoid screw fixation is an accepted surgical approach for type 2 odontoid fractures with an intact transverse ligament. Typically, intraoperative bi-planar flouroscopy is used for placement of an odontoid screw. However, the quality of the images obtained with biplanar flouroscopy in the operating room is variable (due to patient body habitus) and screws may be misplaced. We report our technique for the use of the O-arm (Medtronic Navigation, Louisville, Colorado) to place and revise odontoid screw fixation. Methods and Results: The O-arm is sterilely draped into the surgical field. Intraoperative navigation is not needed. Using anteroposterior and lateral flouroscopic images obtained from the O-arm, the trajectory of the Kirschner wire, drill, tap, and screw can be visualized in real time. The final screw position can then be checked with a computed tomographic reconstruction view done with the O-arm while the patient is still draped sterilely in the operating room. We have utilized the Oarm to avoid a screw malposition in one patient with an odontoid fracture with osteopenia (which made visualization of the cervical spine difficult with standard flouroscopy). We have also utilized O-arm visualization to retrieve a malpositioned and migrated odontoid screw placed outside of our institution.

Efficacy of skull plain films in follow-up evaluation of cerebral aneurysms treated with detachable coils: quantitative assessment of coil mass.

Skull plain films of coiled aneurysms have been used in a limited role, including morphologic comparison of the coil mass. We aimed to evaluate the efficacy of skull plain films in patients treated with detachable coils by using quantitative assessment. In this retrospective study, 78 pairs of the initial and follow-up skull anteroposterior and lateral images were reviewed independently by 2 neuroradiologists. The largest diameter, the perpendicular diameter, and area of the coil mass were measured separately on plain film, and quantitative changes of parameters were compared between subgroups, which were determined by consensus, depending on the need for retreatment. Subgroup analysis was also performed according to aneurysm size, packing attenuation, and ruptured status. On skull lateral images, mean quantitative changes of the largest diameter (0.53 ± 0.43 mm versus 1.17 ± 0.91 mm, P < .01), the perpendicular diameter (0.56 ± 0.48 mm versus 1.20 ± 1.05 mm, P < .01), and the area of the coil mass (5.21 ± 7.51 mm(2) versus 10.55 ± 10.93 mm(2), P < .02) differed significantly between subgroups. Receiver operating characteristic analysis showed quantitative change of the largest diameter (>1.1 mm; sensitivity, 50.0%; specificity, 90.3%), the perpendicular diameter (>.9 mm; sensitivity, 62.5%; specificity, 85.5%), and the area (>8.5 mm(2); sensitivity, 50.0%; specificity, 83.9%) on skull lateral films to be indicative of aneurysm recurrence, and the diagnostic accuracy of these parameters increased significantly in the high-packing-attenuation group. Quantitative measurement of the coil mass by using skull plain lateral images has the potential to predict aneurysm recurrence in follow-up evaluations of intracranial aneurysms with coiling.

Assessment of prosthesis alignment after revision total knee arthroplasty using EOS 2D and 3D imaging: a reliability study.

IntroductionA new low-dose X-ray device, called EOS, has been introduced for determining lower-limb alignment in 2D and 3D. Reliability has not yet been assessed when using EOS on lower limbs containing a knee prosthesis. Therefore purpose of this study was to determine intraobserver and interobserver reliability of EOS 2D and 3D knee prosthesis alignment measurements after revision total knee arthroplasty (rTKA).MethodsForty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Varus/valgus angles were measured in 2D (VV2D) and 3D (VV3D). Intraclass correlation coefficients and the Bland and Altman method were used to determine reliability. T-tests were used to test potential differences.ResultsIntraobserver and interobserver reliability were excellent for VV2D and VV3D. No significant difference or bias between the first and second measurements or the two observers was found. A significant mean and absolute difference of respectively 1.00° and 1.61° existed between 2D and 3D measurements.ConclusionsEOS provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between varus/valgus measurements in 2D and 3D.