What Are the Interobserver and Intraobserver Variability of Gap and Stepoff Measurements in Acetabular Fractures?

BackgroundGap and stepoff values in the treatment of acetabular fractures are correlated with clinical outcomes. However, the interobserver and intraobserver variability of gap and stepoff measurements for all imaging modalities in the preoperative, intraoperative, and postoperative phase of treatment is unknown. Recently, a standardized CT-based measurement method was introduced, which provided the opportunity to assess the level of variability.Questions/purposes(1) In patients with acetabular fractures, what is the interobserver variability in the measurement of the fracture gaps and articular stepoffs determined by each observer to be the maximum one in the weightbearing dome, as measured on pre- and postoperative pelvic radiographs, intraoperative fluoroscopy, and pre- and postoperative CT scans? (2) What is the intraobserver variability in these measurements?MethodsSixty patients with a complete subset of pre-, intra- and postoperative high-quality images (CT slices of < 2 mm), representing a variety of fracture types with small and large gaps and/or stepoffs, were included. A total of 196 patients with nonoperative treatment (n = 117), inadequate available imaging (n = 60), skeletal immaturity (n = 16), bilateral fractures (n = 2) or a primary THA (n = 1) were excluded. The maximum gap and stepoff values in the weightbearing dome were digitally measured on pelvic radiographs and CT images by five independent observers. Observers were free to decide which gap and/or stepoff they considered the maximum and then measure these before and after surgery. The observers were two trauma surgeons with more than 5 years of experience in pelvic surgery, two trauma surgeons with less than 5 years of experience in pelvic surgery, and one surgical resident. Additionally, the final intraoperative fluoroscopy images were assessed for the presence of a gap or stepoff in the weightbearing dome. All observers used the same standardized measurement technique and each observer measured the first five patients together with the responsible researcher. For 10 randomly selected patients, all measurements were repeated by all observers, at least 2 weeks after the initial measurements. The intraclass correlation coefficient (ICC) for pelvic radiographs and CT images and the kappa value for intraoperative fluoroscopy measurements were calculated to determine the inter- and intraobserver variability. Interobserver variability was defined as the difference in the measurements between observers. Intraobserver variability was defined as the difference in repeated measurements by the same observer.ResultsPreoperatively, the interobserver ICC was 0.4 (gap and stepoff) on radiographs and 0.4 (gap) and 0.3 (stepoff) on CT images. The observers agreed on the indication for surgery in 40% (gap) and 30% (stepoff) on pelvic radiographs. For CT scans the observers agreed in 95% (gap) and 70% (stepoff) of images. Postoperatively, the interobserver ICC was 0.4 (gap) and 0.2 (stepoff) on radiographs. The observers agreed on whether the reduction was acceptable or not in 60% (gap) and 40% (stepoff). On CT images the ICC was 0.3 (gap) and 0.4 (stepoff). The observers agreed on whether the reduction was acceptable in 35% (gap) and 38% (stepoff). The preoperative intraobserver ICC was 0.6 (gap and stepoff) on pelvic radiographs and 0.4 (gap) and 0.6 (stepoff) for CT scans. Postoperatively, the intraobserver ICC was 0.7 (gap) and 0.1 (stepoff) on pelvic radiographs. On CT the intraobserver ICC was 0.5 (gap) and 0.3 (stepoff). There was no agreement between the observers on the presence of a gap or stepoff on intraoperative fluoroscopy images (kappa -0.1 to 0.2).ConclusionsWe found an insufficient interobserver and intraobserver agreement on measuring gaps and stepoffs for supporting clinical decisions in acetabular fracture surgery. If observers cannot agree on the size of the gap and stepoff, it will be challenging to decide when to perform surgery and study the results of acetabular fracture surgery.Level of EvidenceLevel III, diagnostic study.     

Curve location influences spinal balance in coronal and sagittal planes but not transversal trunk motion in adolescents with idiopathic scoliosis: a prospective observational study

European Spine Journal - In adolescent idiopathic scoliosis (AIS), spinal deformity can be seen in the thoracic or in the lumbar area. Although differences according to curve location are well...     

Upfront use of eculizumab to treat early acute antibody-mediated rejection after kidney allotransplantation and relevance for xenotransplantation

Acute antibody-mediated rejection (AMR) early after transplant remains a challenge, both in allotransplantation and in xenotransplantation. We report the case of an early and severe acute AMR episode in a kidney transplant recipient that was successfully treated with upfront eculizumab. A 58-year-old woman had been on dialysis since 2014. She underwent a first kidney transplant in 2018 with primary non-function and received several blood transfusions. Postoperatively, she developed anti-HLA antibodies. One year later, she received a second allograft from a deceased donor. At day 0, there was only one preformed low-level donor-specific antibody (DSA) anti-DQ7. After initial excellent allograft function, serum creatinine increased on days 7-9, and this was associated with oligo-anuria. On day 7, there was an increase in her DSA anti-DQ7 and 4 de novo DSA had developed at high MFI values. Allograft biopsy showed severe active AMR with diffuse C4d deposits in peritubular capillaries. The early acute AMR episode was treated with upfront eculizumab administration (2 doses) with efficient CH50 blockade (< 10% CH50). Rituximab was also administered on day 12, and intravenous immunoglobulin (IVIG) was given over the following days. There was an excellent clinical response to eculizumab administration. Eculizumab administration rapidly reversed the acute AMR episode without the need for plasmapheresis. Rituximab and IVIG were also used as B-cell immunomodulators to decrease DSA. Blocking efficiently the terminal complement pathway may become a useful strategy to treat acute AMR in sensitized recipients of allografts, and possibly in recipients of discordant xenografts.     

Does gastric tonometry monitor splanchnic perfusion?

OBJECTIVE: To define whether the gastric mucosal-arterial PCO2 gradient (PCO2 gap) reliably reflects hepatosplanchnic oxygenation in septic patients. DESIGN: Prospective observational clinical study. SETTING: An adult, 31-bed medical/surgical department of intensive care of a university hospital. PATIENTS: A total of 36 hemodynamically stable, invasively monitored, mechanically ventilated, sedated, paralyzed patients with severe sepsis. INTERVENTIONS: In each patient, hepatosplanchnic blood flow was determined by the continuous indocyanine green infusion technique and gastric mucosal PCO2 by the saline tonometry technique. Suprahepatic venous blood oxygen saturation and PCO2 also were measured. The mesenteric veno-arterial PCO2 gradient was determined as the difference between the suprahepatic venous blood PCO2 and the arterial blood PCO2. MEASUREMENTS AND MAIN RESULTS: There were significant correlations between the hepatosplanchnic blood flow and the suprahepatic venous blood oxygen saturation (r2 = .56; p<.01), between the hepatosplanchnic blood flow and the mesenteric veno-arterial PCO2 gradient (r2 = .55; p<.01), and also between the suprahepatic venous blood oxygen saturation and the mesenteric veno-arterial PCO2 gradient (r2 = .64; p<.01). There was no statistically significant correlation between the PCO2 gap and the hepatosplanchnic blood flow, the suprahepatic venous blood oxygen saturation or the mesenteric veno-arterial PCO2 gradient. CONCLUSIONS: In stable septic patients, the PCO2 gap is not correlated with global indexes of gut oxygenation. The interpretation of PCO2 gap is more complex than previously thought.     

Real-world outcomes following 12 months of intravitreal aflibercept monotherapy in patients with diabetic macular edema in France: results from the APOLLON study

Graefe's Archive for Clinical and Experimental Ophthalmology - To report the effectiveness of intravitreal aflibercept (IVT-AFL) treatment for diabetic macular edema (DME) in French clinical...