Preoperative CT Scan Research Articles

Change of vertebral orientation, between the supine position and the prone position.

Our aim was to assess the change of vertebral orientation, expressed in the sagittal plane, in the transversal plane and in the frontal plane, at each level from T1 to S1 between the supine position (like in in a CT scan) and the prone position lying on bolsters like in an OR. Thirty-six patients were selected and included for a total number of one hundred and forty-eight vertebral levels. There were 30 females and 6 males. The mean age was 15years and 9months. A semi-automatic image processing technique and software (3D slicer), with a custom-made python script add-on, was used for each patient: paired preoperative CT scan and intraoperative cone beam computed tomography (CBCT) scan were processed to acquire complete spinal reconstructions in a consistent 3D coordinate system. The aim was to automatically compute a set of sagittal, transversal, and frontal rotations of each vertebral level of the same patient describing the 3D vertebral rotation between the supine position and the prone position lying on bolsters. For sagittal analysis, the results showed a behavior in the evolution of rotation depending on the level. Between T01 and T10, the rotation was between - 14° and - 8°. Between T10 and L05, the sagittal rotation increased from - 10° up to + 10°. For frontal and transversal analysis, the rotations were under 6.5°. These results could be valuable to perform a safe virtual templating: the information given by the virtual templating seems to be more accurate in the transversal plane than in the sagittal plane.

36. Cephalometric Imaging Sheds Light on the Effects of Mandibular Distraction on Infants with Robin Sequence

PURPOSE: Upper airway obstruction (UAO) in infants with Robin Sequence (RS) is secondary to micrognathia and resultant posterior displacement of the tongue. Mandibular distraction osteogenesis (MDO) is a safe and effective treatment for significant UAO, but there is a paucity of data examining associated cephalometric changes. This study carefully examines mandibular cephalometric changes of infants with RS who underwent MDO using internal devices to more deeply understand both immediate and longer-term effects of distraction on mandibular shape. METHODS: Consecutive infant MDO cases (n=53) performed by the same surgeon were analyzed using preoperative and postoperative lateral cephalograms and CT scans of the mandible. Population averages for preoperative and postoperative time points were assessed using a two-sample t-test with equal variance. RESULTS: Significant post-operative morphologic changes were seen in 19 of 21 cephalometric parameters. Length, height, width, and airway parameters improved on average by 20.3 mm (60.7%), 9.8 mm (49.7%), 12.6 mm (36.1%), and 211%, respectively. The majority of cephalometric measurements displayed substantial percent change from the preoperative timepoint to device removal and a much less dramatic percent change from device removal to 6-12 months postoperatively. In fact, none of the parameters measuring mandibular length and angular cephalometrics were significant from device removal to 6-12 months after MDO. CONCLUSION: Cephalometric measurement is a powerful tool that provides a concrete metric to understand how MDO affects not just the immediate but also long-term growth of the mandible. Understanding the more quantifiable effects of mandibular distraction will allow for fine-tuning of surgical practice and optimization of outcomes.

P14 CT SCAN DERIVED PARAMETERS PREDICT LEFT VENTRICLE OBSTRUCTION AFTER TAVI

Abstract Introduction Mid Ventricular (MVO) and Left Ventricular Outflow Tract Obstruction (LVOTO) after Trans–catheter Aortic Valve Implantation (TAVI) have been previously described and are associated with adverse outcome. Pre–procedural identification of patient at risk of MVO and LVOTO after TAVI may help pre–operative risk stratification and patient selection and facilitate intra–operative management, finally improving clinical outcomes. This study aims to identify CT–scan and Echocardiographic predictors of Left Ventricular Obstruction (LVO), defined as the composite of MVO and LVOTO. Methods We retrospectively reviewed pre–operative CT scans and Trans–Thoracic Echocardiography of 349 patients treated with TAVI at our Centre between January 2019 and December 2021. Correlations between post–operative development of MVO and LVOTO and pre–operative Echocardiographic and CT scan measurements were tested. Results LVO occurred in 16.3% of patients after TAVI. At univariate analysis clinical factors associated to LVO were female gender (OR=2.2, p=0.006) and body surface area (OR=0.19, p=0.006); pre–procedural echocardiographic parameters identified were end–diastolic–diameter (OR=0.89, p<0.001) and left ventricular ejections fraction (OR=1.09, p<0.001), whereas pre–procedural CT scan measurements associated to LVO were intraventricular septum to leaflet coaptation length (SLCL; OR=0.87, p<0.001) and left ventricular systolic area (OR=0.9, p<0.001). After multivariate analysis, only left ventricular ejection fraction (OR=1.1, p<0.001) and the CT scan derived parameters SLCL (OR=0.9, p<0.001) and left ventricular area (OR=0.9; p<0.001) were able to predict LVO after TAVI. Conclusions Left ventricle obstruction (LVOTO + MVO) after TAVI can be predicted by CT scan derived parameters. Pre–procedural identification of patients at risk may help intraprocedural and postprocedural management, thus improving clinical outcomes.

Significance of predicted future liver remnant volume on liver failure risk after major hepatectomy: a case matched comparative study.

Future liver remnant volume (FLRV), a risk factor for liver failure (PHLF) after major hepatectomy (MH), is not routinely measured. This study aimed to evaluate the association between FLRV and PHLF. All patients undergoing MH (4 + segments) between 2011 and 2018 were identified from a prospectively maintained single-centre database. Perioperative data were collected for patients with PHLF, who were matched (1:2) with non-PHLF controls. FLRV and FLRV% (i.e., % of total liver volume) were calculated retrospectively from preoperative CT scans using Synapse-3D software, and compared between the PHLF and matched control groups. Of 711 patients undergoing MH, PHLF occurred in 27 (3.8%), of whom 24 had preoperative CT scans available. These patients were matched to 48 non-PHLF controls, 98% of whom were classified as being at high risk of PHLF on preoperative risk scoring. FLRV% was significantly lower in the PHLF group, compared to matched controls (median: 28.7 vs. 35.2%, p = 0.010), with FLRV% < 30% in 58% and 29% of patients, respectively. Assessment of the ability of FLRV% to differentiate between PHLF and matched controls returned an area under the ROC curve of 0.69, and an optimal cut-off value of FLRV% < 31.5%, which yielded 79% sensitivity and 67% specificity. FLRV% is significantly predictive of PHLF after MH, with over half of patients with PHLF having FLRV% < 30%. In light of this, we propose that all patients should undergo risk stratification prior to MH, with the high risk patients additionally being assessed with CT volumetry.

Minimally Invasive Intracerebral Hemorrhage Evacuation Improves Pericavity Cerebral Blood Volume.

Cerebral blood volume mapping can characterize hemodynamic changes within brain tissue, particularly after stroke. This study aims to quantify blood volume changes in the perihematomal parenchyma and pericavity parenchyma after minimally invasive intracerebral hemorrhage evacuation (MIS for ICH). Thirty-two patients underwent MIS for ICH with pre- and post-operative CT imaging and intraoperative perfusion imaging (DynaCT PBV Neuro, Artis Q, Siemens). The pre-operative and post-operative CT scans were segmented using ITK-SNAP software to calculate hematoma volumes and to delineate the pericavity tissue. Helical CT segmentations were registered to cone beam CT data using elastix software. Mean blood volumes were computed inside subvolumes by dilating the segmentations at increasing distances from the lesion. Pre-operative perihematomal blood volumes and post-operative pericavity blood volumes (PBV) were compared. In 27 patients with complete imaging, post-operative PBV significantly increased within the 6-mm pericavity region after MIS for ICH. The mean relative PBV increased by 21.6 and 9.1% at 3 mm and 6 mm, respectively (P = 0.001 and 0.016, respectively). At the 9-mm pericavity region, there was a 2.83% increase in mean relative PBV, though no longer statistically significant. PBV analysis demonstrated a significant increase in pericavity cerebral blood volume after minimally invasive ICH evacuation to a distance of 6 mm from the border of the lesion.

V-001 ROBOTIC E-TEP APPROACH FOR RECURRENT INCISIONAL HERNIA AFTER LAPAROSCOPIC IPOM REPAIR: HAZARD OR RIGHT CHOISE?

Abstract The video shows the case of a 40-year-old male patient with a recurrent umbilical hernia after a laparoscopic IPOM repair. The preoperative CT scan with Valsalva shows a M3 defect with a width of 7 cm at the lower border of the intraperitoneal mesh, associated with upper midline diastasis. We decide to address the hernia repair with a robotic e-TEP approach and a lateral docking. Despite a difficult access and dissection of the retromuscular space due to the adhesions beetwen the rectus muscle and the non-absorbable tacks, the procedure was successful and the patient was discharged the day after the surgery. No complications or recurrence were detected at the 6-month follow-up.

V-023 ETEP REPAIR OF AN M2-3 W2 INCISIONAL HERNIA WITH AN ASSOCIATED SPIEGEL HERNIA. A CASE REPORT

Abstract Aim To describe a case of an extended-view totally extraperitoneal approach for both an M2-3 W2 incisional hernia with an associated right Spiegel hernia. Material &amp; Methods A 68a female with a previous medical history of a midline laparotomy after diffuse peritonitis presented with a midline bulge in the upper third of the previous surgical wound. Preoperative CT scan showed a midline hernia of 4cm and found a right-sided Spiegel hernia of 3cm. Endoscopic treatment of both defects was offered and accepted. Results Patient was placed in supine position. Retromuscular space was created using blunt dissection with a balloon, which helped with direct visualization. Two 5mm trocars were placed in the left pararectal region. Dissection was performed and crossover from left to right was achieved following standard eTEP procedure. Reduction of preperitoneal fat was performed, and midline defects identified. Dissection was continued to the Retzius space and Cooper's ligaments. Identification and reduction of the Spiegel hernia followed. After completing the dissection of the retro rectus and preperitoneal space, primary closure was performed. A lightweight polypropylene mesh was deployed. No complications ocurred and discharge was on the 2nd day. Conclusions Treatment of incisional hernias is in evolution, as minimally invasive techniques have developed greatly since their description and now have a more widespread use among surgeons. eTEP is a novel approach that can be used for the treatment of midline incisional and some primary hernias, as shown in the case, with satisfactory short-term results and similar long-term outcomes to other techniques.

OC-011 SARCOPENIA IN COMPLEX ABDOMINAL WALL SURGERY: IMPACT ON THE POSTOPERATIVE COMPLICATIONS

Abstract Aim Sarcopenia is defined as the skeletal muscle mass loss and is considered as a prognostic factor in oncological surgical patients, liver transplant and trauma surgery. It can be reversed with exercise and diet. Nonetheless there is a lack of evidence of its impact on complex abdominal wall surgery. The aim is to evaluate the impact of sarcopenia in postoperative complications after complex incisional hernia repair. Material and Methods Retrospective study of patients undergoing surgery for complex incisional hernias &amp;gt;10cm (W3 of European Hernia Society classification) between 2014–2021. Sarcopenia was stablished as the skeletal muscle index (SMI), measured at L3 transversal section of a preoperative CT-scan. Previously defined literature-based SMI cutoff values were used: men &amp;lt;52,4cm2/m2, women &amp;lt;38,5cm2/m2. Results We included 105 patients, of which 29 (27,6%) were sarcopenic. The mean follow-up was 24,11 (19,28) months. The mean age and body mass index was 65,34 (10,98) and 31,85 (5,55), respectively. Sarcopenia was significantly associated with a higher risk of death [OR 11,21 (IC95% 2,76–45,52); p=0,001]. We observed a difference in need of intensive care unit (ICU) stay [OR 2,24 (IC95% 0,88–5,69); p=0,089] and cardiac complications [OR 2,96 (IC95% 0,79–11,11); p=0,108], not reaching statistical significance. Differences in surgical site occurrence or infection were not observed. After analysing by possible cofounding factors (age, comorbidities, ICU stay), sarcopenia remains associated with a higher risk of death [OR 9,08 (IC95% 2,08–39,59); p=0,003]. Conclusions Given the results of our study sarcopenia might increase the risk of death, independent of age, comorbidities and ICU stay.

V-048 COMBINED ETEP AND OPEN APPROACH FOR M4 AND L3 VENTRAL HERNIA AFTER COMPLICATED INGUINAL HERNIA REPAIR

Abstract We present the case of a 49 y-o woman with a previous open inguinal hernia repair with a superficial surgical site infection during the immediate postoperative period. She required surgical debridement and negative pressure therapy. Ten months after surgery she persisted with discharge and inflammatory changes. The preoperative CT-scan revealed a misplaced mesh with chronic inflammatory changes in the right inguinal and hypogastric region. An M4 3,5cm diameter defect with a right lateralized 13×5×10cm hernia sac was also observed. A combined open and eTEP approach for mesh removal and retrorectus hernia repair was proposed. Retrorectus dissection began at the left rectus muscle, using two 5 mm trocars for dissection and after crossover a contralateral Hasson trocar was placed. A M4-5W2 and L3 hernia with omental fat and partial bladder sliding into the hernia sac was observed. The right posterior fascia was fibrotic and laterally retracted. After sac contents were fully mobilized, a right partial TAR was necessary in order to close the peritoneum and obtain an adequate dissection for mesh placement. A 25×20cm polypropylene mesh was placed in the retrorectal space. Using a right inguinal incision, previously infected mesh was removed and a silver coated polypropylene mesh was placed below the anterior fascia. The patient was discharged on the third postoperative day and her one month follow up visit was uneventful. We conclude that in this case a hybrid approach can provide an adequate mesh placement via eTEP, with mesh removal by a less invasive approach.

Is preoperative sarcopenia associated with postoperative complications after pelvic exenteration surgery?

PurposePelvic exenteration (PE) involves radical surgical resection of pelvic organs and is associated with considerable morbidity. Sarcopenia is recognised as a predictor of poor surgical outcomes. This study aimed to determine if preoperative sarcopenia is associated with postoperative complications after PE surgery.MethodsThis retrospective study included patients who underwent PE with an available preoperative CT scan between May 2008 and November 2022 at the Royal Adelaide Hospital and St. Andrews Hospital in South Australia. Total Psoas Area Index (TPAI) was estimated by measuring the cross-sectional area of the psoas muscles at the level of the third lumbar vertebra on abdominal CT, normalised for patient height. Sarcopenia was diagnosed based on gender-specific TPAI cut-off values. Logistic regression analyses were performed to identify risk factors for major postoperative complications with a Clavien-Dindo (CD) grade ≥ 3.ResultsIn total, 128 patients who underwent PE were included, 90 of whom formed the non-sarcopenic group (NSG) and 38 the sarcopenic group (SG). Major postoperative complications (CD grade ≥ 3) occurred in 26 (20.3%) patients. There was no detectable association with sarcopenia and an increased risk of major postoperative complications. Preoperative hypoalbuminemia (P = 0.01) and a prolonged operative time (P = 0.002) were significantly associated with a major postoperative complication on multivariate analysis.ConclusionSarcopenia is not a predictor of major postoperative complications in patients undergoing PE surgery. Further efforts aimed specifically at optimising preoperative nutrition may be warranted.

A Pilot Human Cadaveric Study on Accuracy of the Augmented Reality Surgical Navigation System for Thoracolumbar Pedicle Screw Insertion Using a New Intraoperative Rapid Registration Method.

To evaluate the feasibility and accuracy of AR-assisted pedicle screw placement using a new intraoperative rapid registration method of combining preoperative CT scanning and intraoperative C-arm 2D fluoroscopy in cadavers. Five cadavers with intact thoracolumbar spines were employed in this study. Intraoperative registration was performed using anteroposterior and lateral views of preoperative CT scanning and intraoperative 2D fluoroscopic images. Patient-specific targeting guides were used for pedicle screw placement from Th1-L5, totaling 166 screws. Instrumentation for each side was randomized (augmented reality surgical navigation (ARSN) vs. C-arm) with an equal distribution of 83 screws in each group. CT was performed to evaluate the accuracy of both techniques by assessing the screw positions and the deviations between the inserted screws and planned trajectories. Postoperative CT showed that 98.80% (82/83) screws in ARSN group and 72.29% (60/83) screws in C-arm group were within the 2-mm safe zone (p < 0.001). The mean time for instrumentation per level in ARSN group was significantly shorter than that in C-arm group (56.17 ± 3.33s vs. 99.22 ± 9.03s, p < 0.001). The overall intraoperative registration time was 17.2 ± 3.5s per segment. AR-based navigation technology can provide surgeons with accurate guidance of pedicle screw insertion and save the operation time by using the intraoperative rapid registration method of combining preoperative CT scanning and intraoperative C-arm 2D fluoroscopy.

CE-454611-3 HIGH RISK LEFT ATRIAL APPENDAGE CLOSURE IN PATIENTS WITH A PERSISTENT LEFT ATRIAL APPENDAGE THROMBUS

Left atrial appendage closure (LAAC) in patients with a persistent left atrial appendage (LAA) thrombus is controversial. To introduce a novel utilization of a cerebral protection device during high risk LAAC in patients with a persistent LAA thrombus. N/A Case 1: A 50-year-old male with persistent atrial fibrillation (AF) and remote left ventricular thrombus with a thromboembolic stroke presented for an AF ablation. He was found to have a persistent LAA thrombus on multiple pre-operative CT scans despite changing anticoagulation regimen with rivaroxaban and subsequently warfarin with aspirin. The ablation was aborted. He underwent LAAC (Watchman FLXTM, Boston Scientific) with the cerebral protection device (SentinelTM, Boston Scientific) in place. The transesophageal echocardiogram during the procedure confirmed persistent LAA thrombus (Figure A). At the end of the procedure, embolic debris were identified within the SentinelTM (Figure B). The patient was discharged with no neurologic symptoms at the time of discharge and remains neurologically intact 10 months post procedure. Case 2: A 68-year-old female with persistent AF on a therapeutic warfarin dose presented for an AF ablation. She was noted to have a LAA thrombus on the pre-operative CT scan and the procedure was aborted. Her anticoagulation was switched to apixaban. A repeat CT revealed no change in LAA thrombus, and more aggressive anticoagulation was limited by hematuria. Therefore, she underwent LAAC with the SentinelTM for cerebral protection. Of note, the intraoperative TEE revealed filamentous LAA thrombus (Figure C). The patient tolerated the procedure well and was safely discharged the following day. She had no post-operative changes in her neurologic status and the Watchman FLXTM on routine TEE remained in stable position (Figure D). The presence of LAA thrombus is a common concern in patients referred for LAAC. While classically avoided, this case series suggests that a thrombus being present is not a contraindication for LAAC. A cerebral protection device may be used to prevent cardioembolic stroke in selected patients with a persistent LAA thrombus. Further studies are needed to determine the safety and efficacy of this strategy.

Quantifying the Differences between 3D Virtual Planning and Attained Postoperative Reduction on CT for Patients with Tibial Plateau Fractures; a Clinical Feasibility Study.

Background: Three-Dimensional Virtual Planning (3DVP) has been proven to be effective for limiting intra-articular screw penetration and improving the quality of reduction for numerous fractures. However, the value of 3DVP for patients with tibial plateau fractures has yet to be determined. Purposes: The research question of this study is: Can Computed Tomography Micromotion Analysis (CTMA) provide a reliable quantification of the difference between 3DVP and the postoperative reduction on CT for tibial plateau fractures? Methods: Nine consecutive adult patients who received surgical treatment for a tibial plateau fracture and received pre- and postoperative CT scans were included from a level I trauma center in the Netherlands. The preoperative CT scans of the patients were uploaded in a 3DVP software. In this software, fracture fragments were reduced and the reduction was saved as a 3D file (STL). The quality of the reduction from the 3DVP software was compared with the postoperative results using CT Micromotion Analysis (CTMA). In this analysis, the translation of the largest intra-articular fragment was calculated by aligning the postoperative CT with the 3DVP. Coordinates and measurement points were defined in the X, Y, and Z axes. The combined values of X and Y were used to define the intra-articular gap. The Z-axis was defined as the line from cranial to caudal and was used to define intra-articular step-off. Results: The intra-articular step-off was 2.4 mm (Range 0.5-4.6). Moreover, the mean translation of the X-axis and Y-axis, which was defined as the intra-articular gap, was 4.2 mm (Range 0.6-10.7). Conclusions: 3DVP provides excellent insight into the fracture and its fragments. Utilizing the largest intra-articular fragment, it is feasible to quantify the difference between 3DVP and a postoperative CT using CTMA. A prospective study to further analyze the use of 3DVP in terms of intra-articular reduction and surgical and patient-related outcomes has been started by our team.

CT-derived psoas muscle area and density are associated with length of stay and discharge disposition after liver transplantation

Prolonged length of stay (LOS) and discharge disposition following liver transplantation are associated with postoperative complications and increased healthcare utilization. This study evaluated the relationship between CT-derived psoas muscle measurements and hospital LOS, intensive care unit (ICU) LOS, and discharge disposition after liver transplant. The psoas muscle was chosen given its ease of measurement with any radiological software. A secondary analysis assessed the relationship between the American Society for Parenteral and Enteral Nutrition and the Academy of Nutrition and Dietetics (ASPEN/AND) malnutrition diagnosis criteria and CT-derived psoas muscle measures. CT-derived measures of psoas muscle density (mHU) and cross-sectional area at the level of the third lumbar vertebrae were obtained from preoperative CT scans of liver transplant recipients. Cross-sectional area measures were corrected for body size to generate a psoas area index variable (cm2/m2; PAI). Each 1-unit increase in PAI was associated with a reduced hospital LOS of 4 days (R2=0.07). Each 5-unit increase in mean Hounsfield units (mHU) was associated with a reduced hospital and ICU LOS of 5 and 1.6 days, respectively (R2=0.22 and 0.14, respectively). Mean PAI and mHU were higher in patients who discharged to home. PAI was reasonably identified through ASPEN/AND malnutrition criteria, but there was no difference in mHU between those with and without malnutrition. Measures of psoas density were associated with both hospital and ICU LOS and discharge disposition. PAI was associated with hospital LOS and discharge disposition. CT-derived measures of psoas density may be a valuable complement to preoperative liver transplant nutrition assessment using traditional ASPEN/AND malnutrition criteria.

Influence of operative timing on perioperative outcomes of patients with the seatbelt sign

BackgroundThe seatbelt sign (SBS) is a pattern of bruising/contusions on the chest and abdominal wall following motor vehicle collisions. The aim of this analysis is to investigate the influence of time to surgery following identification of the SBS on perioperative outcomes. MethodsA retrospective review of the Trauma Quality Improvement Program database from 2017 to 2019 was performed. Patients included in this retrospective analysis were involved in motor vehicle collisions, experienced blunt abdominal trauma, presented with skin abrasions/contusions in the SBS distribution, were hemodynamically stable, and underwent laparotomy. Demographics, vital signs, injury severity score, Glasgow coma scale, preoperative CT scans (P-CT), and time from presentation to surgery were recorded. Time from presentation to surgery was subdivided by data quartiles as immediate (<1.3 h), early (1.3–4 h), and delayed (>4 h). The influence of operative timing on postoperative mortality, hospital length of stay (LOS), intensive care unit (ICU) LOS, and ventilator days was assessed in multivariate analyses. ResultsA total of 1523 patients were included; 280 underwent immediate, 610 early, and 633 delayed surgery. Patients undergoing surgery in the early and delayed groups who received P-CT scans had shorter mean times to operation (4.52 h vs 5.24 h, p < 0.01). In multivariate analysis, patients who underwent delayed surgery stayed in the hospital 2.5 days longer (p < 0.001), spent 2.8 additional days in the ICU (p < 0.001), and spent 3.75 additional days on a ventilator (p < 0.001) than patients who received early surgery. Within the early and delayed surgical groups, P-CT was associated with lower mortality (OR 0.46 95 % CI 0.24–0.88, p < 0.01) in multivariate analysis. ConclusionsEarly surgical intervention was associated with improved patient outcomes by reducing hospital and ICU LOS and ventilator days. Conducting P-CT reduced the time to surgery and mortality. Utilization of P-CT for screening hemodynamically stable patients with the SBS upon admission may expedite identification of the potential need for surgical management of abdominal injury.

Inter-rater agreement between radiologists using the novel CT-TDV (T3c+; tumour deposits; EMVI) system in patients with potentially curable right colon cancer.

The novel CT-TDV scoring system, identifying T3c + disease; the presence/absence of tumour deposits and EMVI has been shown to be superior in predicting prognosis when compared to the CT-TNM staging system in the evaluation of colon cancer. Reproducibility of this scoring system between specialist GI radiologists has not been assessed previously. The aim of this study was to assess the inter-rater agreement of gastrointestinal radiologists in assessing the novel pre-operative CT-TDV scoring of patients with potentially curable right-sided colon cancer. Ninety-three right colon cancer pre-operative CT scans were graded as CT TDV "good" versus TDV "poor" by four radiologists. Inter-rater agreement was assessed using the intraclass correlation coefficient (ICC) between all four readers and individual readers against the central radiologist using Cohen's κ statistic. The ICC comparing those graded as TDV "good" versus TDV "poor" for all 93 cases was 0.61 (0.51-0.70) indicating moderate reliability. Individual κ scores across the 93 cases were 0.76, 0.59 and 0.59 (p < 0.001) indicating moderate to substantial agreement. The CT TDV scoring system is reproducible amongst trained gastrointestinal radiologists in the assessment of newly diagnosed right colon cancer. This further validates the clinical utility of the CT TDV scoring system as a prognostic tool to guide the management of patients with potentially curable right colon cancer.

Accuracy and Reliability of Computerized Surgical Planning Software in Anatomic Total Shoulder Arthroplasty.

The primary purpose of this study was to assess the concordance between preoperatively determined implant parameters using CT-based planning software and surgically implanted prostheses. Secondarily, we sought to evaluate the agreement between preoperative plans performed by surgeons at different levels of training. Patients with primary glenohumeral osteoarthritis who underwent anatomic total shoulder arthroplasty (aTSA) and had a preoperative CT scan according to Blueprint (Stryker, Mahwah, NJ) protocol to be used for preoperative planning were included. A cohort of short-stemmed (SS) and stemless cases performed between October 2017 and December 2018 was randomly selected from an institutional database for the study. Planning was performed separately by four observers at different levels of orthopedic training at a minimum of six months following the actual surgery. Concordance between the surgical decisions during planning and the actually utilized implants was calculated. Additionally, inter-rater agreement was analyzed using the intra-class correlation coefficient (ICC). Implant parameters assessed were glenoid size, backside radius of curvature, and the need for posterior augment, in addition to humeral stem/nucleus size, head size, head height, and head eccentricity. Twenty-one patients were included (10 stemmed and 11 stemless) with a cohort comprising 12 (57%) females with a median age of 62 years (IQR 59.5,67). There was a total of 544 decision possibilities based on the above parameters. The total number of decisions that matched surgical data was 333 (61.2%). Prediction of glenoid component augmentation need and size was the variable that matched most with surgical data (83.3%), whereas nucleus/stem size was the worst (42.9%). Interobserver agreement was excellent in one variable, good in three variables, moderate in one, and poor in two. The best interobserver agreement was with regard to head height. Preoperative planning using CT-based software may be more accurate for the glenoid component when compared to humeral-sided parameters. Specifically, planning may be most helpful in determining the need and the size of glenoid component augmentation. Utilizing computerized software demonstrates high reliability, even among surgeons early in their orthopedic training.

A multi-view interactive virtual-physical registration method for mixed reality based surgical navigation in pelvic and acetabular fracture fixation.

The treatment of pelvic and acetabular fractures remains technically demanding, and traditional surgical navigation systems suffer from the hand-eye mis-coordination. This paper describes a multi-view interactive virtual-physical registration method to enhance the surgeon's depth perception and a mixed reality (MR)-based surgical navigation system for pelvic and acetabular fracture fixation. First, the pelvic structure is reconstructed by segmentation in a preoperative CT scan, and an insertion path for the percutaneous LC-II screw is computed. A custom hand-held registration cube is used for virtual-physical registration. Three strategies are proposed to improve the surgeon's depth perception: vertices alignment, tremble compensation and multi-view averaging. During navigation, distance and angular deviation visual cues are updated to help the surgeon with the guide wire insertion. The methods have been integrated into an MR module in a surgical navigation system. Phantom experiments were conducted. Ablation experimental results demonstrated the effectiveness of each strategy in the virtual-physical registration method. The proposed method achieved the best accuracy in comparison with related works. For percutaneous guide wire placement, our system achieved a mean bony entry point error of 2.76 ± 1.31mm, a mean bony exit point error of 4.13 ± 1.74mm, and a mean angular deviation of 3.04 ± 1.22°. The proposed method can improve the virtual-physical fusion accuracy. The developed MR-based surgical navigation system has clinical application potential. Cadaver and clinical experiments will be conducted in future.

Correlations between 3D preoperative planning and postoperative reduction in the osteosynthesis of distal humeral fractures

BackgroundThree-dimensional preoperative planning has been applied to the osteosynthesis of distal humerus fractures. The present study investigated the correlations between 3D preoperative planning and postoperative reduction for the osteosynthesis of distal humerus fractures using 3D parameters.MethodsTwenty-three elbows of 23 distal humerus fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. 3D images of the distal humerus were created after taking preoperative CT scans of the injured elbow. Fracture reduction, implant selection, and placement simulations were performed based on 3D images. Postoperative CT images were taken 1 month after surgery. Correlations were evaluated with preoperative plans and postoperative 3D images. The longitudinal axis and coordinates of the humerus were defined on the 3D images. The coronal angle (CA) was defined as the angle formed by the long axis and the line connecting the medial and lateral margins of the trochlea of the humerus on a coronal plane image. The sagittal angle (SA) was defined as the angle formed by the long axis and the line connecting the top of the lateral epicondyle and the center of the humeral capitellum on a sagittal plane image. The axial angle (AA) was defined as the angle between the sagittal plane and the line connecting the medial and lateral margins behind the trochlea of the humerus. The intraclass correlation coefficients (ICC) of each measurement value were assessed between preoperative planning and postoperative images.ResultsPreoperative planning and postoperative measurement values were CA: 85.6 ± 5.9°/85.8 ± 5.9°, SA: 140.9 ± 8.5°/139.4 ± 7.9°, and AA: 84.0 ± 3.1°/82.6 ± 4.9°, respectively. ICCs were CA: 0.75 (P < 0.01), SA: 0.78 (P < 0.01), and AA: 0.34 (P < 0.05), respectively.ConclusionsThe 3D preoperative planning of distal humeral fractures achieved the good correlations of coronal and sagittal angles, but the relatively poor correlation of the axial angle. This may be attributed to an inability to assess the rotation angle during surgery. We propose the measurement indices shown in the present study as a three-dimensional evaluation index for distal humerus fractures.Trial registrationRegistered as NCT04349319 at ClinicalTrials.gov.

Redefining radiocarpal fracture-dislocations with injury specific management and a clinical classification system: a retrospective review.

Unlike articular shear fractures of the distal radius, radiocarpal fracture-dislocations defined as complete dislocation of the lunate from its articular facet of the radius are relatively uncommon. The management principles of these fractures have not been defined and there is no consensus on approach to management of these injuries. The aim of this study is to review our series of radiocarpal fracture-dislocations and propose a radiographic classification to guide surgical management. This study is reported based on STROBE guidelines. A total of 12 patients underwent open reduction and internal fixation. All the fracture-dislocations were dorsal and satisfactory objective outcomes achieved were comparable to literature. Injury morphology-specific management approach was used based on the size of dorsal lip fragment and the volar teardrop fragment attached to the short radiolunate ligament assessed by preoperative CT scans. All patients with known outcome (n = 10) went on to resume their prior occupation and hobbies that included high-demand activities and manual labour at mean follow-up of 27 weeks. Average wrist flexion was 43° and wrist extension was 41° while radial and ulnar deviation were 14° and 18° respectively. Average forearm pronation was 76° and supination was 64° at final follow-up. We describe four injury patterns of radiocarpal fracture-dislocations based on preoperative CT scans that guide fixation. We believe that early recognition of radiocarpal fracture-dislocations and appropriate management can yield satisfactory outcomes.