Postoperative Computed Tomography Images Research Articles

Extensive Aortic Stent Graft Coverage for Thoracoabdominal Aortic Aneurysm is Associated With Hemorrhagic Complications Induced by Disseminated Intravascular Coagulation

Hybrid endovascular repair for thoracoabdominal aortic aneurysm (TAAA) is a less invasive alternative treatment than conventional open repair. However, disseminated intravascular coagulation (DIC) and hemorrhagic complications can occur postoperatively. We investigated risk factors for hemorrhagic complications after hybrid endovascular TAAA repair. Sixty-one patients who underwent elective hybrid endovascular TAAA repair between 2007 and 2020 were included. Laboratory data before and after placing stent graft were collected, and DIC was diagnosed using a scoring system established by the Japanese Association for Acute Medicine. The length of the stent graft used to cover the aorta was defined as the aortic coverage length, which was measured using the first postoperative computed tomography image. Predictors of unexpected hemorrhagic complications were evaluated. Postoperative thrombocytopenia was observed in 57 (93%) patients, and their platelet count decreased significantly after stent graft placement (14.3 [9.5-18.0] vs. 8.2 [5.4-10.9]×104/µL, P < 0.001). Fifteen (25%) and 45 patients (74%) were diagnosed with DIC before and after stent graft placement, respectively. Hemorrhagic complications were observed in 21 patients (34%). Multivariate logistic regression analysis revealed that aortic coverage length was an independent risk factor for hemorrhagic complications (odds ratio 1.441/50 mm increase; 95% confidence interval, 1.041-1.994, P=0.027). The cutoff value for aortic coverage length obtained from the receiver operating characteristic curve (area under the curve=0.72) was 304.4 mm (sensitivity 0.76, specificity 0.70). Aortic coverage length is a risk factor for hemorrhagic complications. Patients undergoing extensive aortic coverage greater than 304 mm should be closely monitored.

Postoperative computed tomography assessment of anteromedial cortex reduction is a predictor for reoperation after intramedullary nail fixation for pertrochanteric fractures.

Postoperative radiographs are routinely used to assess fracture reduction following intramedullary nail fixation for pertrochanteric fractures, even though computed tomography (CT) is a superior modality. We aimed to determine the association between reduction quality assessed by CT and rates of reoperation and to evaluate the association of reoperation and reduction quality according to the assessment modality (plain radiographs vs. CT). A retrospective analysis of 299 consecutive patients treated with intramedullary nail fixation for pertrochanteric fractures was conducted. Fracture reduction measured by postoperative radiographs and CT was categorized as anatomical type, extramedullary type, or intramedullary type. Postoperative data for analysis included reduction status,tip-apex distance(TAD), screw position in the femoral head, sliding distance, and conditions associated with reoperation. Of the 299 patients included with a mean age of 83.1 ± 8.2years, there were six patients who required reoperation (2.0%). According to the CT assessments, there were 42 intramedullary reductions (14.0%). Patients with a non-intramedullary reduction based on postoperative CT images were significantly more likely to have proper placement of the screw, a reduced TAD, a reduced sliding distance, and a lower reoperation rate than those with an intramedullary reduction (P < 0.05). The reduction quality assessed by postoperative CT was significantly associated with reoperation (95% CI, 1.45-29.31). Intramedullary reduction assessed by CT was associated with reoperation. The reduction quality based on CT findings was more predictive for reoperation than that from plain radiographs.

A Anchoring Technique Using Long Bent Rods for Open Reduction of Thoracolumbar Dislocation.

The purpose of this study was to evaluate the effectiveness of a novel surgical open reduction method for thoracolumbar dislocation. This study included a total of 15 patients of thoracolumbar dislocation. All patients underwent posterior thoracolumbar open reduction and fixation using this technique. Preoperative x-ray, computed tomography (CT), and magnetic resonance imaging were used to evaluate the dislocation. The American Spinal Injury Association grade of spinal cord injury before and afer the operation were record. All patients were followed up for 2 years, and x-ray, CT were used to observe postoperative reduction and fusion. Postoperative x-ray and CT images of all patients indicated good recovery of the spinal sequence, and no neurological deterioration or surgically related complications occurred. All patients were followed up for 2 years, no patients were lost to follow-up. During the follow-up period, x-ray and CT images showed no complications related to internal fixation such as fracture and loosening of screws and rods were found. A anchoring technique using long bent rods is a safe, simple, accurate, and easy to replicate and implement method, which can be applied in the surgical treatment for thoracolumbar dislocation.

Safety and Efficacy of All-In-One Percutaneous Pedicle Screw System.

Retrospective study of the prospectively collected outcomes data. The indications for PPS placement during minimally invasive spine stabilization (MISt) procedures have increased in recent years. To the best of our knowledge, no studies have documented the outcomes of PPS insertion using the all-in-one PPS system. This study compared the conventional methods and the use of all-in-one percutaneous pedicle screw (PPS) system with respect to the speed and accuracy of PPS placement. We also determined the advantages associated with the use of the all-in-one PPS system. We evaluated 54 patients who underwent PPS insertion using the conventional method and the all-in-one PPS system during MISt procedures. We also assessed the number of implanted PPSs, the time taken to implant PPSs, and the accuracy of PPS placement based on postoperative computed tomography images. A total of 254 PPSs were inserted (126 using the conventional method and 128 using the all-in-one PPS system). The PPS insertion time with the all-in-one PPS system (mean, 25.3 ± 9.1 s) was significantly shorter than that using the conventional method (mean, 63.1 ± 13.0 s; P < 0.01). With respect to the accuracy of PPS insertion, ≥ 2 mm pedicle breach was noted in one case each in both groups. PPS placement using the all-in-one PPS system is as safe as conventional methods and has the potential to save the surgical time of MISt procedures.

Subaxial Cervical Pedicular Screw Insertion via the Nonanatomic Axis: Technical Notes and Preliminary Clinical Report.

Retrospective study. To report the technical details of subaxial cervical pedicular screw insertion via the nonanatomic axis (nAA-CPS) and evaluate its clinical safety and accuracy. The nAA-CPS technique was performed in 21 patients. Preoperative and intraoperative management-related details are described, and a manipulation protocol is presented. Clinical outcomes were used to assess the safety and accuracy of screws was evaluated using postoperative computed tomography (CT) according to the pedicle perforation grading system, and the nonanatomic pedicle transverse angle (nPTA) and nonanatomic pedicle axis length (nPAL) were assessed based on pre- and postoperative CT images. According to "one constant entry point (EP) and two perpendicular trajectory angles" protocol, nAA-CPS was performed without much interference from the muscles. No intraoperative or postoperative neurovascular complications related to the technique were observed. Of the 112 inserted screws, 78 (69.64%) were assessed as grade 0, 24 (21.43%) as grade 1, 4 (3.57%) as grade 2 and 6 (5.36%) as grade 3. The overall rate of correct position (grades 0 and 1) was 91.07% (102/112), and the rate of malposition was 8.93% (10/112), including five screws implanted medially and the other five laterally. The nPTA was highly consistent on pre- and postoperative CT (P < .05), while postoperative nPAL was significantly shorter than preoperative nPAL (P > .05). Clinically, the accuracy and safety of nAA-CPS was similar to the traditional CPS technique. The protocol, derived from previous radiological studies and workshops, greatly helped standardize clinical manipulation; thus, nAA-CPS is a promising alternative to the traditional CPS.

Robotic-Navigated Percutaneous Pedicle Screw Placement Has Less Facet Joint Violation Than Fluoroscopy-Guided Percutaneous Screws

To directly compare robotic-versus fluoroscopy-guided percutaneous pedicle screw (PPS) placement in thoracolumbar spine trauma with a focus on clinically acceptable pedicle screw accuracy and facet joint violation (FJV). A retrospective chart review assessed 37 trauma patients undergoing percutaneous thoracic and/or lumbar fixation. Postoperative computed tomography images were reviewed by authors blinded to surgical technique who assessed pedicle screw trajectory accuracy and FJV frequency. Seventeen patients underwent placement of 143 PPS with robotic assistance (robot group), compared with 20 patients receiving 149 PPS using fluoroscopy assistance (control group). Overall, the robot cohort demonstrated decreased FJV frequency of 2.8% versus 14.8% in controls (P= 0.0003). When further stratified by level of surgery (i.e., upper thoracic, lower thoracic, lumbar spine), the robot group had FJV frequencies of 0%, 3.2%, and 3.7%, respectively, compared with 17.7% (P= 0.0209), 14.3% (P= 0.0455), and 11.9% (P= 0.2340) in controls. The robot group had 84.6% clinically acceptable screw trajectories compared with 81.9% in controls (P= 0.6388). Within the upper thoracic, lower thoracic, and lumbar regions, the robot group had acceptable screw trajectories of 66.7%, 87.1%, and 90.7%, respectively, compared with 58.8% (P= 0.6261), 91.1% (P=0.5655), and 97.6% (P= 0.2263) in controls. There was no significant difference in clinically acceptable screw trajectory accuracy between robotic versus fluoroscopy-guided PPS placement. However, the robot cohort demonstrated a statistically significantly decreased FJV overall and specifically within the thoracic spine region. Use of robotic technology may improve radiographic outcomes for a subset of patients or spine surgeries.

Long-term variation in skeletal muscle and adiposity in patients undergoing esophagectomy.

SummaryThis study seeks to define long-term variation in body composition in patients undergoing esophagectomy for cancer and to associate those changes with survival. Assessment of skeletal muscle, visceral (VAT) and subcutaneous adipose tissue (SAT) was performed using computed tomography (CT) images routinely acquired: at diagnosis; after neoadjuvant therapy, and; >6 months after esophagectomy. In cases where multiple CT scans were performed >6 months after surgery, all available images were assessed. Ninty-seven patients met inclusion criteria with a median of 2 (range 1–10) postoperative CT images acquired between 0.5 and 9.7 years after surgery. Following surgical treatment of esophageal cancer, patients lost on average 13.3% of their skeletal muscle, 64.5% of their VAT and 44.2% of their SAT. Sarcopenia at diagnosis was not associated with worse overall survival (66.3% vs. 68.5%; P = 0.331). Sarcopenia 1 year after esophagectomy was however associated with lower 5-year overall survival (53.8% vs. 87.5%; P = 0.019). Survival was lower in those patients who had >10% decrease in skeletal muscle index (SMI; 33.3% vs. 72.1%; P = 0.003) and >40% decrease in SAT 1 year after surgery (40.4% vs. 67.4%; P = 0.015). On multivariate analysis, a decline in SMI 1 year after surgery was predictive of worse survival (HR 0.38, 95%CI 0.20–0.73; P = 0.004). This study provides new insight relating to long-term variation in body composition in patients undergoing esophagectomy for cancer. Findings provide further evidence of the importance of body composition, in particular depletion of skeletal muscle, in predicting survival following esophagectomy.

Improving deformable image registration with point metric and masking technique for postoperative breast cancer radiotherapy.

Deformable image registration (DIR) is increasingly used for target volume definition in radiotherapy. However, this method is challenging for postoperative breast cancer patients due to the large deformations and non-correspondence caused by tumor resection and clip insertion. In this study, an improved B-splines based DIR method was developed to address this issue for higher registration accuracy. The conventional B-splines based DIR method was improved with the introduction of point metric and masking technique. The point metric minimizes the distance between 2 point sets with known correspondence for regularization of intensity-based B-splines registration. The masking technique reduces the influence of non-corresponding regions in breast computed tomography (CT) images. Two sets of CT images before and after breast surgery were used for image registration. One set was the diagnostic CT image acquired before surgery, and another set was the planning CT image acquired after surgery for breast cancer radiotherapy. A total of 26 sets of CT images from 13 patients were collected retrospectively for the test. The improved DIR method's registration accuracy was evaluated by target registration error (TRE), the Jacobian determinant, and visual assessment. For soft tissue, the difference in the median TRE between the improved DIR method and the conventional DIR method was statistically significant (2.27 vs. 5.88, P<0.05). The Jacobian determinant of the deformation field was positive for all patients. For visual assessment, the improved DIR method with point metric achieved better matching for soft tissue. The improved DIR method's registration accuracy was higher than the conventional DIR method based on the preliminary results. With point metric and masking technique, the influence of large deformations and non-correspondence on registration between pre- and post-operative CT images can be effectively reduced. Therefore, this method provides a feasible way for target volume definition in postoperative breast cancer radiotherapy treatment planning.

CT-Guided Posterolateral Full-Endoscopic Ventral Decompression for Single-Level Cervical Spondylotic Myelopathy

Percutaneous full-endoscopic surgery was recently developed for the treatment of cervical foraminal stenosis and posterolateral disc herniation. However, there are no studies involving endoscopic surgery to treat cervical spondylotic myelopathy (CSM). To observe the safety, feasibility, and efficacy of posterolateral full-endoscopic ventral decompression (PLEVD) via computed tomography (CT)-guided surgery in patients with single-level CSM. A prospective cohort study. The First Affiliated Hospital of Gannan Medical College. From May 2018 to August 2019, 21 patients with single-level CSM underwent CT-guided PLEVD. The posterolateral angle was measured during surgery. The neurologic condition was evaluated via the Japanese Orthopaedic Association (JOA) score and recovery rate, and a Visual Analog Scale (VAS) was used to measure pain relief. The maximum spinal canal diameter (MSCD) was measured on pre- and postoperative CT images. The mean length of follow-up was 11.3 ± 5.3 months. The average posterolateral angle was 36.0° ± 5.6°. The mean VAS score of limbs significantly decreased after surgery. The mean JOA score improved during the follow-up period. Nineteen of the 21 patients achieved good or excellent outcomes, and 2 patients had fair outcomes according to the JOA score 6 months after surgery. The average MSCD was enlarged from 0.55 ± 0.15 cm preoperatively to 1.02 ± 0.18 cm postoperatively. This study was nonrandomized and provides only preliminary clinical results for single-level CSM. Under appropriate indications, PLEVD under CT guidance is an available and safe technique for treating single-level CSM.

Accuracy and Feasibility Analysis of SEEG Electrode Implantation using the VarioGuide Frameless Navigation System in Patients with Drug-Resistant Epilepsy

The objective of the study was to evaluate the feasibility and accuracy of frameless stereoelectroencephalography (SEEG) electrode implantation in patients with drug-resistant epilepsy using the VarioGuide system. The VarioGuide frameless navigation system was used to implant SEEG electrodes in patients with medically drug-resistant epilepsy. Demographic data, surgery duration, number of electrodes, and complications were retrospectively analyzed. Accuracy was compared by measuring the distance between the planned and actual electrode positions as determined by postoperative computed tomography images. A total of 141 SEEG electrodes were implanted in 19 patients from May 2015 to December 2018 with an average of 7.42 (range: 4-10) leads per patient. The average entry point localization error (EPLE) was 1.96 ± 0.47 mm (range: 0.32-3.29) and average target point localization error (TPLE) was 2.47 ± 0.79 mm (range: 0.72-4.83). The average operating time per lead (OTPL) was 14.16 ± 2.68 minutes (range: 8.64-21.58). No complications occurred. The VarioGuide frameless navigation system can be an effective method for SEEG electrode implantation in patients with drug-resistant epilepsy, particularly when the electrodes are concentrated in a relatively small region and the number of implanted electrodes is small.

Geometric Analysis to Determine Kinking and Shortening of Bridging Stents After Branched Endovascular Aortic Repair

PurposeTo evaluate bridging stent geometry in patients who underwent branched endovascular aortic repair (B-EVAR) and to correlate the outcomes with intrinsic bridging stent characteristics aiming to identify the stent(s) that guarantees the best performance.MethodsPre-operative and post-operative computed tomography images of all patients undergoing B-EVAR between September 2016 and April 2019 were retrospectively analyzed. Following geometrical features were measured: target vessel take-off angle (TOA); longitudinal stent shortening; shape index (SI), intended as ratio between minimum and maximum diameter of the lumen cross sections, averaged on three segments: zone 1 (proximal stented zone), zone 2 (intermediate), and zone 3 (distal).ResultsThirty-eight branches (8 right (RRA) and 8 left renal arteries (LRA), 11 superior mesenteric arteries (SMA), 11 celiac trunks (CTR)) were treated. Fluency (Bard Peripheral Vascular), COVERA (Bard Peripheral Vascular), and VBX (WLGore&Assoc) stent-grafts were implanted in 10, 12, and 16 branches, respectively. Pre-operative TOA was more acute in RRA and LRA when compared to CTR and SMA, and straightened in post-operative configuration (109.86 ± 28.65° to 150.27 ± 21.0°; P < 0.001). Comparable values of SI among the stent types were found in zone 1 (P = 0.08), whereas higher SI in VBX group was detected in zones 2 (P < 0.001) and 3 (P < 0.001). The VBX group was also the most affected by stent shortening (11.12 ± 5.65%; P = 0.001).ConclusionOur early experience showed that the VBX stent offers greater stent circularity than the other devices even if a greater shortening has been observed drawing attention with regards to the decision of the nominal stent length.

Cold Ablation Robot-Guided Laser Osteotome (CARLO®): From Bench to Bedside.

Background: In order to overcome the geometrical and physical limitations of conventional rotating and piezosurgery instruments used to perform bone osteotomies, as well as the difficulties in translating digital planning to the operating room, a stand-alone robot-guided laser system has been developed by Advanced Osteotomy Tools, a Swiss start-up company. We present our experiences of the first-in-man use of the Cold Ablation Robot-guided Laser Osteotome (CARLO®). Methods: The CARLO® device employs a stand-alone 2.94-µm erbium-doped yttrium aluminum garnet (Er:YAG) laser mounted on a robotic arm. A 19-year-old patient provided informed consent to undergo bimaxillary orthognathic surgery. A linear Le Fort I midface osteotomy was digitally planned and transferred to the CARLO® device. The linear part of the Le Fort I osteotomy was performed autonomously by the CARLO® device under direct visual control. All pre-, intra-, and postoperative technical difficulties and safety issues were documented. Accuracy was analyzed by superimposing pre- and postoperative computed tomography images. Results: The CARLO® device performed the linear osteotomy without any technical or safety issues. There was a maximum difference of 0.8 mm between the planned and performed osteotomies, with a root-mean-square error of 1.0 mm. The patient showed normal postoperative healing with no complications. Conclusion: The newly developed stand-alone CARLO® device could be a useful alternative to conventional burs, drills, and piezosurgery instruments for performing osteotomies. However, the technical workflow concerning the positioning and fixation of the target marker and the implementation of active depth control still need to be improved. Further research to assess safety and accuracy is also necessary, especially at osteotomy sites where direct visual control is not possible. Finally, cost-effectiveness analysis comparing the use of the CARLO® device with gold-standard surgery protocols will help to define the role of the CARLO® device in the surgical landscape.

Bone-to-bone ligament preserving laminoplasty technique for reconstruction of laminae.

Introduction:Laminoplasty is a method used in spinal intradural tumor surgery to reduce the possibility of iatrogenic deformity. In classic laminoplasty, the interspinous, supraspinous, and ligamentum flavum integrity may be impaired, thereby creating a risk of deformity despite the laminoplasty. The aim of this study was to review the outcomes of bone-to-bone ligament preserving laminoplasty (BLP laminoplasty) technique.Materials and Methods:The data of 14 cases who underwent BLP laminoplasty for intradural spinal tumor between 2017 and 2019 were reviewed. Through examination of preoperative and postoperative computed tomography images and flexion-extension lateral X-rays, the fusion and kyphotic changes were evaluated in the laminas. An axial Visual Analog Scale (VAS) was used to evaluate clinical satisfaction.Results:The cases comprised 10 females and 4 males, with a mean age of 39.2 years (range, 16–52 years). The masses were intramedullary in six cases and extramedullary in eight. Lumbar region localization was most frequent. Ependymoma was determined in 8 cases, schwannoma in 4, and meningioma in 2. Laminoplasty was applied at 43 levels (10 thoracic and 33 lumbar). No complications were observed, and fusion was obtained in all the cases at the end of 1 year. No segmental kyphotic changes were determined. In the clinical evaluation, the VAS scores improved from 3.4 ± 2.0 preoperatively to 1.8 ± 2.1 postoperatively.Conclusion:BLP laminoplasty is a safe technique which preserves posterior ligamentous integrity. Furthermore, the use of ultrasonic bone scalpel provides a narrower gap between laminae and other bones, preventing dislocation, and allowing for more fusion, and consequently preventing kyphosis.

A computational fluid study on hemodynamics in visceral arteries in a complicated type B aortic dissection after thoracic endovascular repair

ObjectiveTo report a numerical research on the effect of a renal artery arising from false lumen (FL) on the treatment outcome of thoracic endovascular repair (TEVAR) for complicated type B aortic dissection (TBAD). MethodsThe original patient-specific model with the right renal artery (RRA) partially supplied by the FL (TFM) was reconstructed from its postoperative computed tomography images. Two additional models were reconstructed by artificially modifying the RRA either fully arising from the FL(CFM) or true lumen (CTM). Computational fluid dynamics (CFD) simulations were performed. ResultsFirst, for all the models, the flow splits to all the visceral arteries were much less than those of a healthy aorta. Second, the flow split to RRA in the CFM and in CTM was the least and largest respectively. Third, in TFM, the pressure gradient between the true lumen (TL) and FL was negative at the proximal FL and the entire FL was full of active blood flow. In the contrast, in CTM and CFM, the pressure differences between the two lumens remained positive and little flow was present in FL. Finally, both TL and proximal FL of this particular patient expanded and the diameters of all visceral arteries decreased at one-year follow-up. ConclusionsCompared to a healthy aorta, a renal artery arising from FL following TEVAR would result in severe visceral ischemia including RA and superior mesenteric artery (SMA). In addition, our numerical simulation of the postoperative hemodynamics of this particular patient perfectly matched with its TL remodeling, FL expansion and contraction of the visceral arteries at one-year follow-up, and a patient-specific CFD simulation may be adopted to obtain information on visceral perfusion after endovascular repair for TBAD patients.

Prosthetic Accuracy Depends on the Design of Patient-Specific Instrumentation: Results of a Retrospective Study Using Three-Dimensional Imaging.

To determine accuracy of patient-specific instrumentation (PSI), the preoperative three-dimensional (3D) plan should be superimposed on the postoperative 3D image to compare prosthetic alignment. We aimed to compare prosthetic alignment on a preoperative 3D computed tomography (CT) plan and postoperative 3D-CT image, and evaluate the accuracy of PSI during total knee arthroplasty (TKA). Thirty consecutive knees (30 patients) who underwent TKA using PSI were retrospectively evaluated. The preoperative plan was prepared using 3D CT acquisitions of the hip, knee, and ankle joints. The postoperative 3D CT image obtained 1 week after surgery was superimposed onto the preoperative 3D plan using computer software. Differences in prosthetic alignment between the preoperative and postoperative images were measured using six parameters: coronal, sagittal, and axial alignments of femoral and tibial prostheses. Differences in prosthetic alignment greater than 3 degrees were considered outliers. Two observers performed all measurements. All parameters were repeatedly measured over a 4-week interval. This measurement method's intraobserver and interobserver reliabilities were more than 0.81 (very good). For the femoral and tibial prostheses, absolute differences between the preoperative and postoperative 3D CT images were significantly larger in the sagittal than in the coronal and axial planes (p < 0.001). The outlier rate for the sagittal alignment of femoral and tibial prostheses was significantly higher than that for the alignment of coronal and axial planes (p < 0.001). However, there were no significant differences in the range of motion (ROM) before and after TKA when comparing cases with and without outliers in the sagittal plane. Even though the present study did not reveal any issues with the ROM that depended on the presence of an outlier, accurate verification of prosthetic alignment for individual PSI models may be necessary because the designs, referenced images, and accuracy are different in each model.

The accuracy of a novel pedicle screw insertion technique assisted by a special angular scale in the subaxial cervical spine using lateral mass as a reference marker

BackgroundPosterior cervical pedicle screw (CPS) internal fixation has better biomechanical stability than other posterior cervical fixation methods. However, this technique is limited in clinical practice due to the complex anatomical structure and the adjacent relationship of the cervical pedicle, and the high risk of neurovascular injury. The purpose of this study was to describe a novel subaxial CPS insertion technique assisted by a special angular scale using lateral mass as a reference marker and to evaluate the accuracy of CPS placement and the distribution characteristics of CPS misplacement.MethodsA total of 36 patients with subaxial cervical spine diseases who underwent posterior CPS fixation were consecutively selected. The optimal entry point on the posterior surface of the lateral mass was identified on the three-dimensional cervical model reconstructed from preoperative computed tomography (CT) images. The pedicle transverse angle (PTA) and pedicle-lateral mass angle (PLMA) were measured on the transverse and sagittal CT images respectively. The pedicle screws were inserted according to the preoperatively planned entry point and angles. We analysed the postoperative CT images for CPS misplacement rates and perforation directions following the Lee classification.ResultsOverall, 177 pedicle screws were inserted, of which 119 (67.2%) were classified as grade 0, 43 (24.3%) as grade 1, 12 (6.8%) as grade 2 and 3 (1.7%) as grade 3 by the postoperative CT images. The accuracy rate of CPS placement was 91.5%. Of the 15 misplaced pedicle screws (grades 2 and 3), 11 were lateral pedicle perforations, 3 were superior perforations and 1 was an inferior perforation. There were no neurovascular injuries related to CPS misplacement.ConclusionsWith our technique, the optimal entry point and two angles (PTA and PLMA) were identified for CPS insertion. The novel CPS insertion technique assisted by a special angular scale provides high accuracy and few complications.

Accuracy of Le Fort I osteotomy with combined computer-aided design/computer-aided manufacturing technology and mixed reality

The aim of this study was to verify the reproducibility and accuracy of preoperative planning in maxilla repositioning surgery performed with the use of computer-aided design/manufacturing technologies and mixed reality surgical navigation, using new registration markers and the HoloLens headset. Eighteen patients with a mean age of 26.0 years were included. Postoperative evaluations were conducted by comparing the preoperative virtual operation three-dimensional image (Tv) with the 1-month postoperative computed tomography image (T1). The three-dimensional surface analysis errors ranged from 79.9% to 97.1%, with an average error of 90.3%. In the point-based analysis, the errors at each point on the XYZ axes were calculated for Tv and T1 in all cases. The median signed value deviation of all calculated points on the XYZ axes was −0.03mm (range −2.93mm to 3.93mm). The median absolute value deviation of all calculated points on the XYZ axes was 0.38mm (range 0mm to 3.93mm). There were no statistically significant differences between any of the points on any of the axes. These values indicate that the method used was able to reproduce the maxilla position with high accuracy.

Dependence of knee range of motion on the alignment of femoral and tibial components after medial unicompartmental knee arthroplasty

This study evaluated the relationship between postoperative knee flexion angles and the position of femoral and tibial components in unicompartmental knee arthroplasty (UKA). Eighteen patients (atotalof 22 knees: three men, four knees; 15 females, 18 knees) who underwent navigation-assisted UKA were included. Pre- and postoperative computed tomography images were applied on 3D software, which were matched and used to calculate the position of femoral and tibial components. Correspondingly, we investigated the relationship between the knee range of motion (ROM) at 1-year postoperative follow-up and the position of femoral and tibial components. At 1-year post-UKA, the knee flexion angle was associated with the posterior flexion angle of tibial components. This particular angle was significantly greater in the group with equal or greater postoperative knee ROM compared to preoperative ROM (5.2 ± 2.1°) than in the group with less postoperative knee ROM compared to preoperative ROM (2.6 ± 1.6°, p < 0.01). There was no significant difference between both groups in the femoral component position, preoperative posterior slope of the medial tibial plateau, change in the pre- to postoperative posterior tibial slope, and postoperative knee society score. The posterior flexion angle of the tibial component affected the improvement/deterioration of the postsurgery knee flexion angle in navigation-assisted UKA. For improved outcomes after UKA using navigation systems, surgeons should aim to achieve a 5° to 8° posterior flexion angle of the tibial component.

The length of the left superior pulmonary vein stump after left upper lobectomy depends on its position to the left atrial appendage.

BackgroundA longer left superior pulmonary vein (LSPV) stump may increase the risk for postoperative cerebral infarction. Although the residual stump is generally longer after left upper lobectomy (LUL) than for other lobectomies, the length of the LSPV stump after LUL may be influenced by the anatomical relationship between the left atrial appendage (LAA) and the LSPV. Our aim in this study was to investigate the influence of this anatomical relationship on the residual length of the LSPV stump after LUL.MethodsThis was a retrospective analysis of 85 patients who underwent LUL at our institution, between January 2014 and March 2018. Based on pre-operative computed tomography (CT) images, the anatomical relationship between the LSPV and the LAA was classified into two patterns, namely an antero-superior and a postero-inferior pattern. The length of the LSPV stump for these two patterns was evaluated on postoperative CT images and compared between the two groups.ResultsOf the 85 patients, 49 were classified in the antero-superior pattern and 36 in the postero-inferior pattern. The mean length of the LSPV stump after LUL, overall, was 21.9 (range, 15–38) mm, with the stump being significantly longer for the antero-posterior (24.2 mm) than postero-inferior (18.9 mm) pattern.ConclusionsThe anatomical relationship between the LSPV and LAA, identified on pre-operative CT images, was associated with the length of the LSPV stump after LUL.

Minimally invasive surgery versus standard posterior approach for Lenke Type 1-4 adolescent idiopathic scoliosis: a multicenter, retrospective study.

To compare the safety and efficacy of posterior minimally invasive surgery (MIS) to standard posterior spinal fusion (PSF) surgery for Lenke Type 1-4 adolescent idiopathic scoliosis (AIS). This multicenter retrospective study enrolled 112 patients with Lenke Type 1-4 AIS who treated with MIS (n = 64) or PSF (n = 48) between March 2007 and January 2015. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. Operative time, level of fusion, intraoperative blood loss, blood transfusion, and intraoperative radiation exposure were recorded. 22-item Scoliosis Research Society questionnaire (SRS-22) was applied for assessment of life quality. The accuracy of pedicle screw placement was assessed according to postoperative computed tomography images, and the complications were collected in follow-up period. The baseline characteristics of 2 groups were matched. There was no significant difference between 2 groups in terms of radiographic parameters immediately after surgery and at the last follow-up. The MIS group had significantly longer operative time, more level of fusion, less intraoperative blood loss, and lower blood transfusion rate (p < 0.001). The evaluation of pain using SRS-22 showed significantly lower score in MIS group (p < 0.05). No significant difference was found between 2 groups in terms of accuracy of pedicle screw placement and complications. Posterior MIS is a safe and effective alternative to standard open approach for Lenke Type 1-4 AIS patients with curves < 70° and reasonable flexibility. Mid-term results showed MIS had the advantages of less blood loss and pain with more fusion segments.