Liver anatomy for totally laparoscopic segment 7 resection from a caudal magnified view-a 3-dimensional computed tomographic analysis.

BACKGROUND: Laparoscopic resection of hepatic segment 7 is considered particularly difficult. We analyzed anatomic variation of this segment in caudally oriented 3-dimensional (3D) magnified computed tomographic (CT) images obtained prior to liver resection. METHODS: Analysis included 105 patients with preoperative 3D CT evaluation preceding liver resection for hepatobiliary malignancies between April 2021 and April 2024. RESULTS: Five ramification patterns were evident from a caudal magnified view. Some patients who had multiple segment 7 (S7) portal pedicles and an S7 pedicle branching ventrally posed difficulty in performing segmentectomy for the exact extent of S7. Distance from the point where a perpendicular line from the right rim of the inferior vena cava (IVC) intersected the right posterior portal pedicle to the point of bifurcation of the S6 and 7 pedicles was 34.6 mm (range, 3.9-78.8; mean ± standard deviation, 35.2 ± 14.8 mm). The median angle between the perpendicular line from the right rim of the IVC and the line from the root of the S7 pedicle to the right rim of the IVC was 77° (10-140); the mean ± standard deviation was 75.3° ± 28.1. Differences among ramification patterns also were evident. The angle between the right posterior portal pedicle and the S7 pedicle was 143° (79-215) or 143.3 ± 26.7, and that between S7 and S6 pedicles was 71°(15-123) or 75.5 ± 21.7°, representing relatively little variation. CONCLUSIONS: Understanding these details of caudal-view anatomy may resolve difficulties and clarify access required for exposing S7 portal pedicles.

Quantification of 3-Dimensional Confluence-Atrial Morphology in Supracardiac Total Anomalous Pulmonary Venous Connection.

Background: Pulmonary vein stenosis (PVS) continues to be a major complication after surgical repair of total anomalous pulmonary venous connection (TAPVC). Recent studies suggest that the morphology of pulmonary venous confluence and the left atrium (LA) is associated with PVS. However, there are limited data on the prognostic value of integrating quantitative confluence-atrial morphology into risk stratification. Objectives: This study sought to evaluate the prognostic impact of novel imaging metrics derived from 3-dimensional (3D) computed tomography angiography (CTA) modeling on postsurgical PVS (PPVS) in the supracardiac TAPVC (sTAPVC) setting. Methods: Patients undergoing sTAPVC repair in 2017 to 2022 from 3 centers were retrospectively reviewed. Study investigators developed 3D CTA modeled geometric features to quantify confluence-atrial morphology that were analyzed with regard to PPVS. Results: Of the 162 patients (median age 61 days; 55% having preoperative pulmonary venous obstruction [prePVO]) included, 47 (29%) with PPVS at a median of 1.5 months ([quartile 1-quartile 3: 1.5-3.0 months]). In the univariable analysis, the indexed total volume of the LA and confluence (iTVLC) and the ratio of the corresponding confluence length to the mean distance between the LA and confluence (CCL/mDBLC ratio) were significantly associated with PPVS. In a multivariable model adjusting for prePVO and age, the iTVLC and CCL/mDBLC ratio independently predicted PPVS (HR: 1.15; 95% CI: 1.06-1.25; and HR: 1.20; 95% CI: 1.08-1.35, respectively, all P < 0.01). Specifically, an iTVLC ≥20 cm3/m2 and a CCL/mDBLC ratio ≥7.7 were significantly associated with a reduced risk of PPVS. Conclusions: Quantification of 3D confluence-atrial morphology appears to offer a deeper and better metric to predict PPVS in patients with sTAPVC.

Comparison of the quadrant method measuring four points and bernard method in femoral tunnel position evaluation on 3-dimensional reconstructed computed tomography after anatomical single-bundle anterior cruciate ligament reconstruction.

PURPOSE: This prospective study aimed to compare the postoperative evaluation of the quadrant method measuring four points and Bernard method in femoral tunnel position evaluation on 3-Dimensional (3D) reconstructed computed tomography (CT) following the arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruction. METHODS: Thirty-eight patients with ACL tears that were reconstructed using single-bundle ACL reconstruction between May 2021 and March 2023 were included in this study. Postoperative 3D CT images were obtained after the operation. The femoral tunnel position was measured by use of the quadrant method measuring four points and Bernard method. RESULTS: Average mean position of the femoral tunnel insertion center on the 3D CT image was at 26.16 ± 6.27% in the x-coordinate and at 24.36 ± 5.52% in the y-coordinate according to the Bernard method. Meanwhile, the position of the femoral insertion of the ACL measured by the quadrant method measuring four points was 24.2% ± 6.86% in the x-coordinate and 21.16% ± 5.14% in the y-coordinate. CONCLUSIONS: Both the quadrant method measuring four points and Bernard method were effective in femoral tunnel position evaluation on 3D reconstructed CT. Application of the quadrant method measuring four points on 3D CT showed the advantage that measurement can be taken regardless of the shape of the bone tunnel.

Use of 3D-CT-derived psoas major muscle volume in defining sarcopenia in colorectal cancer.

BACKGROUND: Sarcopenia is characterized by reduced skeletal muscle volume and is a condition that is prevalent among elderly patients and associated with poor prognosis as a comorbidity in malignancies. Given the aging population over 80 years old in Japan, an understanding of malignancies, including colorectal cancer (CRC), complicated by sarcopenia is increasingly important. Therefore, the focus of this study is on a novel and practical diagnostic approach of assessment of psoas major muscle volume (PV) using 3-dimensional computed tomography (3D-CT) in diagnosis of sarcopenia in patients with CRC. METHODS: The subjects were 150 patients aged ≥ 80 years with CRC who underwent primary tumor resection at Juntendo University Hospital between 2004 and 2017. 3D-CT measurement of PV and conventional CT measurement of the psoas major muscle cross-sectional area (PA) were used to identify sarcopenia (group S) and non-sarcopenia (group nS) cases. Clinicopathological characteristics, operative results, postoperative complications, and prognosis were compared between these groups. RESULTS: The S:nS ratios were 15:135 for the PV method and 52:98 for the PA method. There was a strong positive correlation (r = 0.66, p < 0.01) between PVI (psoas major muscle volume index) and PAI (psoas major muscle cross-sectional area index), which were calculated by dividing PV or PA by the square of height. Surgical results and postoperative complications did not differ significantly in the S and nS groups defined using each method. Overall survival was worse in group S compared to group nS identified by PV (p < 0.01), but not significantly different in groups S and nS identified by PA (p = 0.77). A Cox proportional hazards model for OS identified group S by PV as an independent predictor of a poor prognosis (p < 0.05), whereas group S by PA was not a predictor of prognosis (p = 0.60). CONCLUSIONS: The PV method for identifying sarcopenia in elderly patients with CRC is more practical and sensitive for prediction of a poor prognosis compared to the conventional method.

Segmentectomy-oriented anatomical model for enhanced precision surgery of the left upper lobe.

Objective: To optimize surgical outcomes and minimize complications in complex segmentectomy of the left upper lobe, we investigated the topographical anatomy of the left upper lobe and developed a segmentectomy-oriented anatomical model. Methods: A state-of-the-art 3-dimensional computed tomography workstation was used to visualize the intersegmental planes and associated veins to categorize the anatomical patterns influencing surgical procedures during left upper lobe segmentectomy. This included the central vein affecting S1+2 (apicoposterior segment) segmentectomy, the transverse S3 (anterior segment) affecting S3 segmentectomy, and other venous branching patterns in 395 patients who underwent thoracic surgery at our institution. Results: The central vein was observed in 32% of the patients, necessitating access from the interlobar area after segmental artery and bronchus division. Transverse S3 incidence was 27%, revealing that only one-third of the patients required complete left upper lobe transection between S4 and S3 during S3 segmentectomy. A significant negative correlation was observed between the presence of transverse S3 and the central vein (<10% of patients with the central vein had transverse S3 and vice versa). In 6% of patients, the lingular segmental veins partially or entirely drained into the inferior pulmonary vein, potentially causing excessive or insufficient resection during surgery. Conclusions: This study offers valuable insights into the topographic anatomy of the left upper lobe and presents a segmentectomy-oriented anatomical model for complex segmentectomies. Our approach enables a more precise and individualized surgical planning for patients undergoing segmentectomy based on their unique anatomy, which could thereby lead to improved patient outcomes.

Reliability of the Tibial Spine Versus ACL Stump in Assisting Tibial Tunnel Positioning During ACL Reconstruction: Analysis Based on 3-Dimensional Computed Tomography Modeling.

Background: Several techniques have been used by surgeons for anatomic tibial tunnel placement in anterior cruciate ligament (ACL) reconstruction, including the ACL stump positioning (ASP) technique and the tibial spine positioning (TSP) technique. Purpose/Hypothesis: The purpose of this study was to evaluate whether bony landmarks (medial and lateral tibial spine [MLTS]) can be a reliable reference for improving the accuracy of tibial tunnel placement in anatomic single-bundle ACL reconstruction compared with the ACL stump. It was hypothesized that the MLTS would not be a reliable bony landmark for tibial tunnel placement. Study Design: Cohort study; Level of evidence, 3. Methods: The 3-dimensional computed tomography images of 111 patients who underwent ACL reconstruction between 2020 and 2021 were included in this study. For tibial tunnel placement, the ASP technique was used in 49 patients, and the TSP technique was used in 62 patients. The 3-dimensional computed tomography images were reconstructed to enable measurements of the locations of the MLTS and tunnel center based on a grid method. Statistical analysis was conducted to compare the MLTS location and tibial tunnel position as well as the accuracy (mean distance of each actual location from the anatomic center) and precision (standard deviation of the accuracy, indicating the reproducibility of the tunnel position) of the tunnel position between the ASP and TSP groups. Results: Significant differences were observed between the ASP and TSP groups in terms of the tibial tunnel position on the mediolateral axis (46.7% ± 2.0% vs 45.9% ± 2.2%, respectively; P = .034), while no significant differences were found in terms of the accuracy (4.1% vs 4.6%, respectively; P = .259) or precision (2.1% vs 2.1%, respectively; P = .259) of tibial tunnel positioning between the 2 groups. Conclusion: In anatomic single-bundle ACL reconstruction, the use of the MLTS for tibial tunnel placement achieved comparable accuracy and precision compared with the use of ACL remnants, supporting its role as a reliable bony landmark in tibial tunnel positioning.

Analysis of the therapeutic effect and postoperative complications associated with 3-dimensional computed tomography navigation-assisted intervertebral foraminoscopic surgery in lumbar disc herniation in the elderly: a retrospective cohort study.

Background: With the increasing aging of the population, the incidence of lumbar disc herniation (LDH) is gradually increasing. The 3-dimensional (3D) computed tomography (CT) navigation-assisted intervertebral foraminoscopic surgery for LDH is minimally invasive, and due to its localization and guidance features, it can precisely reach the target location. This study sought to investigate the treatment effect and the incidence of postoperative complications of 3D CT navigation-assisted intervertebral foraminoscopic surgery in elderly patients with LDH to provide a reference basis for improving patient prognosis. Methods: We retrospectively included 213 elderly patients with LDH admitted to our hospital from October 2017 to October 2021 in this study and followed them up for 1 year. Among them, 103 patients (Group A) underwent conventional C-arm fluoroscopy-assisted system alone intervertebral foraminoscopic surgery, and 110 patients (Group B) underwent 3D CT navigation-assisted intervertebral foraminoscopic surgery. The general characteristics of the participants were compiled using a general information questionnaire designed by the investigator. The t-test and chi-square test were used to analyze the relationship between the treatment outcomes and surgical modalities. Binary logistics regression was used to analyze the independent risk factors affecting patient outcomes. Results: The patients who underwent 3D CT navigation-assisted intervertebral foraminoscopic surgery had significantly better outcomes than those who underwent conventional C-arm fluoroscopy-assisted system alone intervertebral foraminoscopic surgery. The binary logistic regression analysis results showed that in addition to the surgical method [odds ratio (OR) =0.258, P=0.042], the history of lumbar trauma (OR =11.001, P=0.005), usual work intensity (OR =4.589, P=0.002), disease duration (OR =3.587, P=0.017), the presence of diabetes (OR =3.315, P=0.026), the presence of a ruptured annulus fibrosus (OR =3.485, P=0.012), the degree of disc degeneration (OR =3.899, P=0.009), and the number of punctures (OR =0.412, P=0.034) were independent risk factors affecting patient outcomes. Conclusions: 3D CT navigation-assisted intervertebral foraminoscopic surgery for LDH effectively reduced the number of punctures, decreased intraoperative bleeding and postoperative drainage volumes, shortened the length of hospitalization, bed rest time and operative time, reduced stress reactions, decreased the degree of low-back pain, and the risk of complications, had better overall efficacy, and significantly improved patient prognosis.

Usefulness of 3-Dimensional Computed Tomography Assessment of Femoral Tunnel after Anterior Cruciate Ligament Reconstruction.

Positioning of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction is the most crucial factor for successful procedure. Owing to the inter-individual variability in the intra-articular anatomy, it can be challenging to obtain precise tunnel placement and ensure consistent results. Currently, the three-dimensional (3D) reconstruction of computed tomography (CT) scans is considered the best method for determining whether femoral tunnels are positioned correctly. Postoperative 3D-CT feedback can improve the accuracy of femoral tunnel placement. Precise tunnel formation obtained through feedback has a positive effect on graft maturation, graft failure, and clinical outcomes after surgery. However, even if femoral tunnel placement on 3D CT is appropriate, we should recognize that acute graft bending negatively affects surgical results. This review aimed to discuss the implementation of 3D-CT evaluation for predicting postoperative outcomes following ACL re-construction. Reviewing research that has performed 3D CT evaluations after ACL reconstruction can provide clinically significant evidence of the formation of ideal tunnels following anatomic ACL reconstruction.

Native Glenoid Depth and Hill-Sachs Lesion Morphology in Traumatic Anterior Shoulder Instability.

BACKGROUND: Although Hill-Sachs lesions (HSLs) are assumed to be influenced by glenoid characteristics in the context of bipolar bone loss, little is known about how glenoid concavity influences HSL morphology. PURPOSE: To investigate the relationship between the native glenoid depth and HSL morphological characteristics. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Computed tomography images of bilateral shoulders from 151 consecutive patients with traumatic unilateral anterior shoulder instability were retrospectively reviewed. Patients were categorized into flat (<1 mm), moderate (1-2 mm), and deep (>2 mm) groups based on the native glenoid depth measured from the contralateral unaffected shoulder. The HSL morphological characteristics included size (depth, width, length, and volume), location (medial, superior, and inferior extent), and orientation (rim and center angle). The glenoid characteristics included diameter, depth, version, and bone loss. The patient, glenoid, and HSL morphological characteristics were compared among the 3 depth groups. Subsequently, the independent predictors of some critical HSL morphological characteristics were determined using multivariate stepwise regression. RESULTS: After exclusion of 55 patients, a total of 96 patients were enrolled and classified into the flat group (n = 31), moderate group (n = 35), and deep group (n = 30). Compared with those in the flat group, patients in the deep group were more likely to have dislocation (38.7% vs 93.3%; P = .009) at the primary instability and had a significantly larger number of dislocations (1.1 ± 1.0 vs 2.2 ± 1.8; P = .010); moreover, patients in the deep group had significantly deeper, wider, larger volume, more medialized HSLs and higher incidences of off-track HSLs (all P≤ .025). No significant differences were detected among the 3 groups in HSL length, vertical position, and orientation (all P≥ .064). After adjustment for various radiological and patient factors in the multivariate regression model, native glenoid depth remained the strongest independent predictor for HSL depth (ß = 0.346; P < .001), width (ß = 0.262; P = .009), volume (ß = 0.331; P = .001), and medialization (ß = -0.297; P = .003). CONCLUSION: The current study sheds light on the association between native glenoid depth and the morphology of HSLs in traumatic anterior shoulder instability. Native glenoid depth was independently and positively associated with HSL depth, width, volume, and medialization. Patients with deeper native glenoids were more likely to have off-track HSLs and thus require more attention in the process of diagnosis and treatment.

Combined 3-Dimensional CT and Multidirectional CT Arthrography for Femoroacetabular Impingement and Hip Lesions: A Cross-sectional Study Comparing Imaging and Hip Arthroscopic Surgery Findings.

Background: There is limited research investigating the diagnostic strength of 3-dimensional computed tomography (3D-CT) and multidirectional CT arthrography (CTA) for femoroacetabular impingement (FAI) and related hip lesions. Purpose: To evaluate the diagnostic strength of combined 3D-CT and CTA in patients with FAI and related hip lesions by comparing it with hip arthroscopic surgery findings. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: This study included patients who were suspected of having FAI and related hip lesions and who underwent a combination of 3D-CT and CTA and subsequent hip arthroscopic surgery between December 2013 and December 2017. The CT and intraoperative arthroscopic findings were recorded and compared. The sensitivity, specificity, and accuracy of 3D-CT for FAI and those of CTA for related hip lesions were calculated. Results: A total of 114 patients with 114 hips were included in our study. There were 101 patients with positive findings and 13 patients with negative findings for FAI (including cam, pincer, and combined morphology) according to 3D-CT. The sensitivity, specificity, and accuracy of 3D-CT for FAI were 91.58%, 57.14%, and 89.47%, respectively. The sensitivity, specificity, and accuracy of CTA for labral tears were 94.64%, 100.00%, and 94.73%, respectively. For acetabular cartilage defects, the sensitivity, specificity, and accuracy of CTA were 60.71%, 91.37%, and 76.31%, respectively. For femoral cartilage defects, the sensitivity, specificity, and accuracy of CTA were 82.22%, 76.81%, and 78.94%, respectively. Conclusion: The study results indicated that 3D-CT was able to provide excellent accuracy for FAI compared with hip arthroscopic surgery findings. In addition, multidirectional CTA demonstrated promising diagnostic strength for hip lesions such as labral tears and chondral defects.

Intrathoracic pouch migration in one-anastomosis gastric bypass with and without hiatoplasty: A 3-dimensional-computed tomography volumetry study.

BACKGROUND: Currently, 4.8% of bariatric operations worldwide are one-anastomosis gastric bypass (OAGB) procedures. If a hiatal hernia is detected in a preoperative gastroscopy, OAGB can be combined with hiatoplasty. Intrathoracic pouch migration (ITM) is common after bypass procedures because the fundus, a natural abutment, is separated from the pouch. OBJECTIVE: The aim of this study was to find out whether OAGB or OAGB combined with hiatoplasty carries a higher risk of ITM and, therefore, also gastroesophageal reflux disease (GERD). SETTING: University hospital. METHODS: Fifty patients (group 1: 25× primary OAGB; group 2: 25× primary OAGB with hiatoplasty) were included in this study. History of weight, GERD, and quality of life were recorded in patient interviews and pouch volume and ITM were evaluated using 3-dimensional-computed tomography volumetry. RESULTS: There were no differences in terms of patient characteristics, history of weight, pouch volume, or quality of life between both groups. ITM was found in group 1 in 60% (n = 15) and group 2 in 76% (n = 19) of all patients (P = .152). The ITM mean length was significantly lower in group 1 with .9 ± 1.1 cm than in group 2 with 1.8 ± 1.2 cm (P = .007). Regarding GERD, there was no difference between both groups; nevertheless, significantly more patients with ITM (38.2%; n = 13) had GERD compared with patients without ITM (6.3%; n = 1). CONCLUSION: In primary OAGB, an additional hiatoplasty was not associated with higher rates of ITM or GERD; nevertheless, the length of ITM was higher after hiatoplasty. If ITM occurs, patients have a risk of developing GERD.

Left ventricular remodeling following septal myectomy in hypertrophic obstructive cardiomyopathy.

Objectives: The purpose of this study is to determine whether or not left ventricular remodeling can be induced after septal myectomy in patients with obstructive hypertrophic cardiomyopathy, and if so, how it occurs, using gated cardiac computed tomography. Methods: Fifty patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy along the septal band between March 2016 and July 2020 were retrospectively reviewed. Recent consecutive 19 patients underwent postoperative cardiac computed tomography. In these patients, volumes of the septal band and thickness of 17 left ventricular myocardial segments were measured to determine the changes after surgery. Results: The resection volume predicted by preoperative computed tomography and the actual resection volume were 6.7 ± 3.3 mL and 6.4 ± 2.7 mL. In-hospital mortality was 0%. Moderate or greater mitral valve regurgitation and systolic anterior motion decreased from 56% to 6% and 86% to 6%, respectively. Median preoperative ventricular septal thickness and left ventricular outflow tract pressure gradient at rest decreased from 20.0 mm (interquartile range, 17.0-24.0 mm) and 74.0 mm Hg (interquartile range, 42.5-92.5 mm Hg) to 14.0 mm (interquartile range, 11.5-16.0 mm) and 15.5 mm Hg (interquartile range, 12.1-21.5 mm Hg), respectively. Postoperative computed tomography confirmed a reduction in septal band volume of 5.7 ± 2.8 mL. Total left ventricular myocardial volume was reduced by 12.9 ± 8.8 mL, which exceeded the volume reduction of the resected septal band. All segments except the basal inferior and basal inferolateral regions showed a significant decrease in wall thickness by a median of 6.4%. Conclusions: Properly performed septal myectomy may induce remodeling of the entire left ventricle, not just the resected area.

Significance of Measuring Lumbar Spine 3-Dimensional Computed Tomography Hounsfield Units to Predict Screw Loosening.

BACKGROUND: Osteoporosis is a well-known risk factor of screw loosening. Classically, dual-energy x-ray absorptiometry (DEXA) scan is an easy and cost-effective method of detecting bone mineral density (BMD). However, T-score on DEXA scan can be overestimated in patients with degenerative changes of the spine. Our objective was to identify correlation between Hounsfield unit (HU) measured by 3-dimensional computed tomography (3D-CT) and screw loosening. METHODS: A total of 113 patients treated with lumbosacral spinal fusion were reviewed and categorized into a screw loosening group and a normal group to compare their average values of preoperative CT HU. Screw loosening was defined as radiolucent area around screw that was thicker than 1 mm with a "double halo sign". RESULTS: There were statistically significant differences in patient age and steroid use between screw loosening and non-loosening groups. There was no significant difference in BMD or T-score between the 2 groups. However, HU values measured in axial, coronal, and sagittal images were significantly different between the 2 groups. In the receiver operating characteristic for HU values measured in CT images, the greatest area under the curve was 0.774 and that was in case of Hounsfield unit measured by axial CT images from L1 to L4. CONCLUSIONS: Preoperative CT HU is associated with screw loosening. It can be a better predictor of screw loosening than DEXA scan. The best predictor of screw loosening in this study is the average value of HU from L1 to L4 in axial cut.

Thoracoscopic right middle lobe subsegmentectomy: A single-center, retrospective review.

Objective: The right middle lobe subsegmentectomy (including multisubsegmentectomy and subsubsegmentectomy) has never been reported. This study aimed to describe a thoracoscopic right middle lobe subsegmentectomy. Methods: This retrospective study included 94 patients who underwent thoracoscopic right middle lobe subsegmentectomy between August 2018 and February 2021. All procedures were performed with the help of the preoperative 3-dimensional computed tomography bronchography and angiography. Results: Ninety-four patients underwent thoracoscopic right middle lobe subsegmentectomy. The median operative time was 56 minutes (range, 35-86 minutes) and median blood loss was 86 mL (range, 50-150 mL). The median duration of chest tube retention was 2.5 days (range, 1-4 days). There were neither cases of postoperative right middle lobe torsion nor instances of perioperative death. The median size of the tumor in the resected segment was 1.3 cm (range, 1.1-1.8 cm). The median margin was 3.3 cm (range, 2.9-4.3). There were 88 cases of lung cancer and 6 cases of benign lesions. The median number of N1 lymph nodes sampled was 3 (range, 2-4). No lymph node involvement was observed postoperatively. No recurrence or mortality was observed during the median follow-up period of 26 months (range, 6-36 months). Conclusions: Thoracoscopic right middle lobe subsegmentectomy is feasible and safe. It may be valuable to preserve the lung parenchyma in patients with noninvasive lung cancer, multiple lung cancer, and benign diseases. Long-term lung function, survival, and cancer-free data are being collected.

Anatomical study of all carpal and adjoining bones of the wrist using 3D CT reconstruction -Finding the ultimate biomechanical theory.

BACKGROUND: The complex interplay of single wrist bones acting in combination with their ligamentous connections is still not fully understood. In this regard various theories exist, divisible in columnar and ring/row theories. The object of this study was to examine the mobility of the individual carpal bones as well as the ulna and metacarpals relative to each other in wrists of cadaveric hands using CT scans. METHODS: The regular wrist mobility of a total of 21 cadaveric hands was examined by CT imaging in neutral position, radial/ulnar abduction as well as wrist flexion and extension. The data were evaluated as 3D models by using a standardized global coordinate system and object coordinate systems. Rotation and translation of each carpal bone as well as radius/ulna and all metacarpal bones were evaluated. RESULTS: The principal motion took place in the carpus between the radius and the proximal carpal row followed by the midcarpal joint and the carpometacarpal joints and not mainly between the individual bones of a row. The scaphoid moves out of its row aggregate mainly during flexion and adapts to the motion of the distal carpal row. The trapezium and first metacarpal bones play a specific role detached from the remaining bones. CONCLUSIONS: With this study, a better understanding of the motion of the individual bones of the carpus, the metacarpals and the radius/ulna is shown. The study supports the row theory, where most motion takes place between the individual rows and not between the carpal bones, leaving the scaphoid and the first ray in a special role between the rows.

Factors influencing postoperative residual diastasis after the operative treatment of acute Lisfranc fracture dislocation.

INTRODUCTION: Clinically, surgeons may frequently encounter residual diastasis between the medial cuneiform and 2nd metatarsal base after the operative treatment of acute Lisfranc fracture dislocations. The purpose of this study was to identify factors influencing postoperative residual diastasis. We specifically focused on the preoperative fracture pattern using 3-dimensional computed tomography (3D-CT). MATERIALS AND METHODS: Radiographic and clinical findings of 66 patients who underwent operative treatment for acute Lisfranc fracture dislocation were reviewed. Patients were grouped according to residual diastasis evaluated by weight-bearing anteroposterior radiograph of the foot at the final follow-up. Residual diastasis was defined as distance between the medial cuneiform and 2nd metatarsal base greater than the distance on the contralateral side by 2 mm or more. Demographic parameters and fracture patterns based on preoperative foot 3D-CT were compared. A paired t test was used to compare continuous numeric parameters, while a Chi-square test was used for the proportional parameters. Statistical significance was set at P value less than 0.05 for all analyses. RESULTS: The mean age at operation, sex, body mass index, and the rate of underlying diabetes were not significantly different between the two groups (P > 0.05 each). Preoperative foot 3D-CT evaluation showed that the rate of large (> 25% of 2nd tarsometatarsal joint involvement), displaced (> 2 mm) fracture fragments on the plantar side of the 2nd metatarsal base was more pronounced in the group with residual diastasis (P = 0.001), while medial wall avulsion of the 2nd metatarsal base was more frequent in the group without residual diastasis (P = 0.001). CONCLUSIONS: While treating acute Lisfranc injuries, surgeons should be aware of the presence of a 2nd metatarsal base plantar fracture. A dorsoplantar inter-fragmentary fixation can be considered if the fragment is large and displaced.

Bipolar Bone Defects in Shoulders With Primary Instability: Dislocation Versus Subluxation.

BACKGROUND: In shoulders with traumatic anterior instability, a bipolar bone defect has been recognized as an important indicator of the prognosis. PURPOSE: To investigate bipolar bone defects at primary instability and compare the difference between dislocation and subluxation. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: There were 156 shoulders (156 patients) including 91 shoulders with dislocation and 65 shoulders with subluxation. Glenoid defects and Hill-Sachs lesions were classified into 5 size categories on 3-dimensional computed tomography (CT) scans and were allocated scores ranging from 0 (no defect) to 4 points (very large defect). To assess the combined size of the glenoid defect and Hill-Sachs lesion, the scores for both lesions were summed (range, 0-8 points). Patients in the dislocation and subluxation groups were compared regarding the prevalence of a glenoid defect, a bone fragment of bony Bankart lesion, a Hill-Sachs lesion, a bipolar bone defect, and an off-track Hill-Sachs lesion. Then, the combined size of the bipolar bone defects was compared between the dislocation and subluxation groups and among patients stratified by age at the time of CT scanning (<20, 20-29, and ≥30 years). RESULTS: Hill-Sachs lesions were observed more frequently in the dislocation group (75.8%) compared with the subluxation group (27.7%; P < .001), whereas the prevalence of glenoid defects was not significantly different between groups (36.3% vs 29.2%, respectively; P = .393). The combined defect size was significantly larger in the dislocation versus subluxation group (mean ± SD combined defect score, 2.1 ± 1.6 vs 0.8 ± 0.9 points, respectively; P < .001) due to a larger Hill-Sachs lesion at dislocation than subluxation (glenoid defect score, 0.5 ± 0.9 vs 0.3 ± 0.6 points [P = .112]; Hill-Sachs lesion score, 1.6 ± 1.2 vs 0.4 ± 0.7 points [P < .001]). Combined defect size was larger in older patients than younger patients in the setting of dislocation (combined defect score, <20 years, 1.6 ± 1.2 points; 20-29 years, 1.9 ± 1.5 points; ≥30 years, 3.4 ± 1.6 points; P < .001) but was not different in the setting of subluxation (0.8 ± 1.0, 0.7 ± 0.9, and 0.8 ± 0.8 points, respectively; P = .885). An off-track Hill-Sachs lesion was observed in 2 older patients with dislocation but was not observed in shoulders with subluxation. CONCLUSION: The bipolar bone defect was significantly more frequent, and the combined size was greater in shoulders with primary dislocation and in older patients (≥30 years).

Cluster analysis of emphysema for predicting pulmonary complications after thoracoscopic lobectomy.

OBJECTIVES: Despite significant advances in surgical techniques, including thoracoscopic approaches and perioperative care, the morbidity rate remains high after lung resection. This study focused on a low attenuation cluster analysis, which represented the size distribution of pulmonary emphysema and assessed its utility for predicting postoperative pulmonary complications after thoracoscopic lobectomy. METHODS: From April 2013 to September 2018, lung cancer patients who received spirometry and computed tomography (CT) before surgery and underwent thoracoscopic lobectomy were included. The cumulative size distribution of the low attenuation area (LAA, defined as ≤-950 Hounsfield unit on CT) clusters followed a power-law characterized by an exponent D-value, a measure of the complexity of the alveolar structure. D-value and LAA% (LAA/total lung volume) were calculated using preoperative 3-dimensional CT software. The relationship between pulmonary complications and patient characteristics, including D-value and LAA%, was investigated. RESULTS: Among 471 patients, there were 61 respiratory complication cases (12.9%). Receiver operation characteristic curve analysis revealed that the best predictive cut-off value of D-value and LAA% for pulmonary complications was 2.27 and 16.5, respectively, with an area under the curve of 0.72 and 0.58, respectively. D-value was significantly correlated with % forced expiratory volume in 1 s. Per univariate analysis, gender, smoking history, forced expiratory volume in 1 s/forced vital capacity, LAA% and D-value were risk factors for predicting postoperative pulmonary complications. In the multivariate analysis, D-value remained a significant predictive factor. CONCLUSION: Preoperative assessment of emphysema cluster analysis may represent the vulnerability of the operated lung and could be the novel predictor for pulmonary complications after thoracoscopic lobectomy.

Utility of skull radiographs in infants undergoing 3D head CT during evaluation for physical abuse.

BACKGROUND: Clinical practice guidelines recommend performing head CT and skull radiographs (SR) when evaluating infants for physical abuse. We compared the accuracy of 3-dimensional CT (3DCT) and SR for detecting skull fractures. METHODS: We reviewed children <12 months evaluated for physical abuse undergoing 3DCT and SR between January 2017 and December 2018. 3DCT and SR images were blindly read by 2 radiologists. Interrater reliability (IRR) was calculated. Diagnostic accuracy was compared using McNemar's test. RESULTS: 158 infants with a mean age of 5.0 months underwent 3DCT and SR. Consensus reading identified 46 fractures (29.1%) on 3DCT and 40 fractures (25.3%) on SR. IRR was higher for 3DCT (κ = 0.95) than for SR (=0.65). 11 fractures were identified on 3DCT but not SR. 5 fractures were identified on SR but not 3DCT. There was no difference in the diagnostic accuracy of 3DCT and SR (χ2 = 1.56, p = 0.211). CONCLUSIONS: We found no difference in the accuracy of 3DCT and SR for detecting skull fractures in infants. Because 3DCT has better IRR and evaluates for both bony and intracranial injuries it is superior to SR. Omitting SRs may be acceptable if a 3DCT is performed, and would reduce radiation exposure without compromising diagnostic accuracy.