Postoperative Computed Tomography Images Research Articles

Application and evaluation of carbonate apatite granules for mandibular bone defect reconstruction after jawbone cyst enucleation-a retrospective case series.

To evaluate the effectiveness of CO3Ap granules in the mandibular bone defects by using computed tomography (CT) images. This study was retrospective case series of mandibular bone defect reconstruction using CO3Ap granules. Six patients with jawbone cysts treated by simultaneous grafting CO3Ap granules after cyst enucleation were enrolled. Patients without grafting CO3Ap granules were excluded. Mandibular bone height including buccolingual bone height, the change of perpendicular distance between the buccolingual line to the alveolar ridge, and the three-dimensional volume of remaining CO3Ap granules were analyzed using CT images obtained at 3, 6, 12, 18, and 24 months postoperatively. Postoperative CT images showed that cortical and cancellous bone-like structures were formed on the grafting area periphery and inside the defect, respectively, with gradual resorption of the CO3Ap granules. Furthermore, there was no evidence of leaving bone defect even at the center of the lesion when the defect was successfully reconstructed by filling it with CO3Ap granules. The percentage volume of remaining CO3Ap granules to the volume at 3 months postoperatively were 76.1 ± 13.1%, 35.8 ± 22.5%, 25.0 ± 13.0%, and 9.9 ± 6.4% at 6, 12, 18, and 24 months postoperatively, and the volume reduction rate increased significantly within 12 months postoperatively. Grafting CO3Ap granules after the enucleation of a jawbone cyst is a good reconstructive treatment option for postoperative prosthetic treatment because CO3Ap granules are gradually replaced by new bone while preserving the contour of the mandibular bone. Not applicable.

Rotation Preserving Fixation for the Treatment of C1 Burst Fracture Combined With Type II Odontoid Fracture: 2 Case Reports and Literature Review.

This study aimed to evaluate the clinical feasibility and effectiveness of a monoaxial screw-rod system and anterior screw fixation for C1 and type II odontoid fractures. We conducted a retrospective review of 2 consecutive patients with acute C1 and Anderson-D'Alonzo type II odontoid fractures. Both patients underwent treatment using a posterior monoaxial screw-rod system and anterior screw fixation. We reviewed their clinical records, including the visual analog pain scale and Neck Disability Index scores, as well as pre- and postoperative radiographs. Additionally, pre- and postoperative computed tomography images were used to classify the fracture types and assess the C1 to C2 reduction, rotation, and instability. Both patients presented with type II C1 and type II B odontoid fractures, combined with Dickman type II transverse atlantal ligament injuries. All surgical procedures were successfully performed without complications such as vertebral artery injury, neurological deficit, esophageal injury, or wound infection. Both patients achieved almost complete bone healing of the fractures, and C1 to C2 rotation was well preserved (32° and 49°) without atlantoaxial instability after follow-ups of 21 and 25 months, respectively. A monoaxial screw-rod system and anterior screw fixation could be promising surgical strategies for C1 fractures combined with type II odontoid fractures, even in cases involving transverse atlantal ligament injuries. The preservation of C1 to C2 rotation without atlantoaxial instability was observed after fixation. However, extensive case-finding and long-term follow-up are needed to understand the effectiveness of this treatment. In order to preserve the C1-C2 rotation, a monoaxial screw-rod system and anterior screw fixation may be more suitable for patients with C1 fractures combined with type II odontoid fractures.

Relations between bone density from computed tomography and bone regeneration after reduction mandibuloplasty

BackgroundBone regeneration in the mandibular angle region after reduction mandibuloplasty may compromise the aesthetics of the lower face and thus lead to revision surgery. Bone quality is known to play an important role in osteogenesis. However, no study has evaluated the relationship between mandibular bone quality and bone regeneration volume. MethodsThe bone density of the mandibular angle immediately after surgery (BD) was determined as the grey level in computed tomography (CT) images. Based on the immediate postoperative and long-term follow-up CT images, the volumes of the regenerated angle (VSA) and the regenerated outer cortex (VOC) were measured after model reconstruction, automatic alignment and Boolean operation. Correlation analyses were then performed between VSA and BD, VOC and BD. Results23 patients (46 mandibular angles) were included in this study. The average BD was 907.09 ± 111.89 HU. The mean VSA was 201.66 (131.73–357.24) mm3. Spearman correlation analysis revealed a positive correlation between BD and VSA (r = 0.5449, p < 0.0001). The mean VOC was 236.23 ± 151.35 mm3. Pearson correlation analysis found a negative correlation between BD and VOC (r = -0.3501, p = 0.0171). ConclusionsCT images can provide a quantitative assessment of mandibular bone quality. BD may influence the volumes of bone regeneration in different areas of the mandibular angle portion after reduction mandibuloplasty, in the regenerated angle area positively and in the regenerated outer cortex region negatively. Therefore, slight over-grinding may be a choice to prevent secondary angulation.

Tomographic Assessment of Fusion Rate, Implant-Endplate Contact Area, Subsidence, and Alignment With Lumbar Personalized Interbody Implants at 1-Year Follow-Up.

Incongruity between irregularly shaped vertebral endplates and the uniform surfaces of stock interbody fusion cages has been identified as contributing to cage subsidence, pseudarthrosis, and unpredictable alignment. Advances in manufacturing techniques have driven the development of personalized interbody cages (PICs) that can match individual endplate morphology and provide the exact shape and size needed to fill the disc space and achieve the planned correction. This study used computed tomography (CT) imaging to evaluate the implant-endplate contact area, fusion, subsidence, and achievement of planned alignment correction in patients receiving PIC devices. This retrospective study included patients treated for adult spinal deformity at a single site and implanted with PIC devices at L4 to L5 or L5 to S1 for segmental stabilization and alignment correction, who received 1-year postoperative CT images as part of their standard of care. An evaluation using 3-dimensional thin-section scans was conducted. Implant-endplate contact and signs of fusion were assessed in each CT slice across both endplates. The degree of subsidence as well as measures of segmental and global lumbar alignment were also assessed. Fifteen patients were included in the study, with a mean age of 68.2 years. Follow-up ranged between 9 and 14 months. Twenty-six total lumbar levels were implanted; 20 with PIC devices via the anterior lumbar interbody fusion approach, 2 with stock cages via the anterior lumbar interbody fusion approach, and 4 with PIC devices via the transforaminal lumbar interbody fusion approach. CT analysis of PIC-implanted levels found an overall implant-endplate contact area ratio of 93.9%, a subsidence rate of 4.5%, a fusion rate of 100%, and satisfactory segmental and global lumbar correction compared with the preoperative plan. PIC implants can provide nearly complete contact with endplate surfaces regardless of the individual endplate morphology. Subsidence, fusion, and alignment assessments in this tomographic study illustrated results consistent with the benefits of a personalized interbody implant.

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

PurposeThis 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.MethodsThirty-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.ResultsAverage 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.ConclusionsBoth 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.

Component rotational mismatch in the standing position is a potential risk factor for unfavourable functional outcomes after total knee arthroplasty.

This study assessed rotational mismatch between components after total knee arthroplasty (TKA) in the supine and standing positions and aimed to investigate the effect of rotational mismatch in the standing position on postoperative patient-reported outcome measures (PROMs). Seventy-one patients (71 knees) who underwent TKA for medial knee osteoarthritis were used to investigate rotational mismatches between components. Rotational mismatches between components were examined on postoperative standing whole-leg and supine knee radiographs using a three-dimensional-to-two-dimensional model image registration technique, and the angles between the reference axes of the components were measured. Component alignment was evaluated using postoperative computed tomography images, and a questionnaire (2011 version of the Knee Society Score: [KSS 2011]) was mailed to investigate postoperative PROMs. In the entire cohort, rotational mismatches in the supine and standing positions were similar (p = 0.9315). In 15% of patients, the mismatch was large (>5°) in the supine position but small (<5°) in the standing position (overestimated group). However, in 23% of patients, the mismatch was small (<5°) in the supine position and large (>5°) in the standing position (underestimated group). The underestimated group had severe preoperative varus deformity, resulting in external rotation of both femoral and tibial components. Rotational mismatch in the standing position (p = 0.0032) was a significant risk factor for unfavourable PROMs. Patients with a mismatch in the standing position had significantly lower scores than those without a mismatch (p = 0.0215), exceeding the minimal clinically important difference values. The underestimated group is clinically important because the surgical procedure and intraoperative assessment of component placement are performed in the supine position. In cases of severe preoperative varus deformity, care should be taken not to place the component in malrotation to avoid rotational mismatch in the standing position. Ⅳ, Case series.

Periacetabular osteotomy using computed tomography-based navigation: preoperative planning and accuracy evaluation

PurposeSince 2011, we have used computed tomography (CT)-based navigation to perform safe and accurate rotational acetabular osteotomy (RAO) for treating developmental dysplasia of the hip. We developed a new method with four fiducial points to improve the accuracy of a published technique. In this study, we introduced a new method to achieve reorientation in accordance with planning and evaluated its accuracy.MethodsThis study included 40 joints, which underwent RAO used CT-based navigation. In 20 joints, reorientation was confirmed by touching the lateral aspect of the rotated fragment with navigation and checking whether it matched the preoperative plan. A new fiducial point method was adopted for the remaining 20 joints. To assess the accuracy of the position of the rotated fragment in each group, postoperative radial reformatted CT images were obtained around the acetabulum and three-dimensional evaluation was performed. The accuracy of acetabular fragment repositioning was evaluated using the acetabular sector angle (ASA).ResultsThe absolute value of ΔASA, which represents the error between preoperative planning and the actual postoperative position, was significantly smaller in the new fiducial method group than the previous method group in the area from 11:30 to 13:30 (p < 0.05). The Harris Hip Score at 1 year after surgery did not differ significantly between the previous and new fiducial point methods.ConclusionThe new fiducial point method significantly reduced reorientation error in the superior-lateral area of the acetabulum: significantly fewer errors and fewer cases of under-correction of lateral acetabular coverage were recorded. The four-reference fiducial method facilitates reorientation of the acetabulum as planned, with fewer errors. The effect of the improved accuracy of the fiducial point method on clinical outcomes will be investigated in the future work.

Development of Air Cell System Following Canal Wall Up Mastoidectomy for Pediatric Cholesteatoma.

Background: The development of temporal bone pneumatization is related to the postnatal middle ear environment, where the development of air cells is suppressed with otitis media in early childhood. However, whether air cell formation restarts when mastoidectomy is performed during temporal bone pneumatization remains unclear. Herein, we evaluated temporal bone pneumatization after canal wall up (CWU) tympanomastoidectomy for middle ear cholesteatoma in children. Methods: In total, 63 patients, including 29 patients with congenital cholesteatoma (CC) and 34 patients with acquired cholesteatoma (AC), were assessed using a set of pre- and postoperative computed tomography images. The air cells of the temporal bone were divided into five areas: periantral (anterior), periantral (posterior), periantral (medial), peritubal, and petrous apex. The number of areas with air cells before and after surgery was compared to evaluate temporal bone pneumatization after surgery. Results: A total of 63 patients, comprising 29 with CC and 34 with AC (pars flaccida; 23, pars tensa; 7, unclassified; 4), were evaluated. The median age of patients (18 males and 11 females) with CC was 5.0 (range, 2-15 years), while that of the AC group (23 males and 11 females) was 8 (range, 2-15 years). A significant difference in air cell presence was identified in the CC and AC groups after surgery (Mann-Whitney U, p < 0.001 and p = 0.003, respectively). Between the two groups, considerably better postoperative pneumatization was observed in the CC group. A correlation between age at surgery and gain of postoperative air cell area development was identified in the CC group (Spearman's rank-order correlation coefficient, r = -0.584, p < 0.001). In comparison with the postoperative pneumatization rate of each classified area, the petrous apex area was the lowest in the CC and AC groups. Conclusions: Newly developed air cells were identified in the temporal bones after CWU mastoidectomy for pediatric cholesteatoma. These findings may justify CWU tympanomastoidectomy, at least for younger children and CC patients, who may subsequently develop air cell systems after surgery.

Accuracy and Clinical Outcomes of Fluoroscopy-Guided and Robotic-Assisted Percutaneous Pedicle Screw Fixation Performed by a Single Surgeon at a Single Center

Objective: Fluoroscopy-guided percutaneous pedicle screw fixation (FGPSF) and its further development, robot-assisted percutaneous pedicle screw fixation (RAPSF), are minimally invasive spinal surgery (MISS) techniques. FGPSF is a standard technique at our hospital, and RAPSF incorporating artificial intelligence has been performed at our hospital since October 2021. This study compared these 2 techniques and analyzed their differences, accuracy, and clinical outcomes based on our experiences.Methods: This study conducted a detailed analysis of screw accuracy and the clinical outcomes of 2 MISS techniques, FGPSF, and RAPSF. Screw accuracy was evaluated using the Gertzbein and Robbins scale, categorizing placements into grades A–E, with grades A and B considered clinically acceptable. Accuracy was assessed using postoperative computed tomography images for FGPSF and intraoperative O-arm scan images for RAPSF. Clinical outcomes were compared by examining parameters, such as hospitalization duration, C-reactive protein (CRP) normalization period, estimated blood loss (EBL), and preoperative/postoperative visual analogue scale (VAS) scores. Screw-related complications were reviewed. Independent image evaluations by nonparticipating spine specialists ensured objective and reliable assessments.Results: Both FGPSF and RAPSF demonstrated high rates of clinically acceptable screw placement, with minimal breaches that required no repositioning. The clinically acceptable rates of FGPSF and RAPSF were similar (99.17% and 99.19%, respectively). Both groups also demonstrated similar clinical outcomes. The CRP normalization period, EBL, and ΔVAS (preoperative—postoperative) scores revealed no statistically significant differences between FGPSF and RAPSF. Neither group experienced screw-related complications; however, the RAPSF group exhibited a statistically significant shorter hospital stay than the FGPSF group.Conclusion: This study compared the accuracy and clinical outcomes of FGPSF and RAPSF. Both methods demonstrated no significant differences in accuracy or clinical outcomes. Spine surgeons selected between the 2 methods based on individual patient needs, and additional research is required to fully understand the practical advantages of each technique in the clinical field.

Comparison of Cervical Pedicle Screw Placement Accuracy With Robotic Guidance System Versus Image Guidance System Using Propensity Score Matching.

A retrospective study. To compare the accuracy of cervical pedicle screw (CPS) placement using a robotic guidance system (RGS) with that of using an image guidance system (IGS; navigation system) through propensity score matching. The RGS may provide accurate CPS placement, which may outperform IGS. However, no study has directly compared the accuracy of CPS placement with the RGS to that with the IGS. We retrospectively reviewed the data of patients who had undergone cervical fusion surgery using CPS with the RGS or IGS. To adjust for potential confounders (patient demographic characteristics, disease etiology, and registration material), propensity score matching was performed, creating robotic guidance (RG) and matched image guidance (IG) groups. The accuracy of CPS placement from C2 to C6, where the vertebral artery runs, was evaluated on postoperative computed tomography images according to the Neo classification (grade 0 to grade 3). Furthermore, the intraoperative CPS revisions and related complications were examined. Using propensity score matching, 22 patients were included in the RG and matched groups each, and a total of 95 and 105 CPSs, respectively, were included in the analysis. In both the axial and sagittal planes, the clinically acceptable rate (grades 0 + 1) of CPS placement did not differ between the RG and matched IG groups (97.9% vs 94.3% and 95.8% vs 96.2%, respectively). The incidence of CPS revision was similar between the groups (2.1% vs 2.9%), and no CPS-related complications were documented. Meanwhile, the incidence of lateral breach (grades 1 + 2 + 3) was significantly lower in the RG group than in the matched IG group (1.1% vs 7.7%, P= 0.037). The RGS and IGS can equally aid in accurate and safe CPS placement in clinical settings. Nonetheless, RGS can further reduce the lateral breach, compared with IGS.

Morphologic prognostic factor for thoracoabdominal aortic dilation after acute type A dissection repair.

Risk factors for late-term aortic dilation after acute type A aortic dissection repair have not been well examined. The goal of this study was to determine the relationship between the abdominal aortic true lumen location and thoraco-abdominal aortic dilation after surgical repair for acute type A aortic dissection. Patients who were preoperatively diagnosed with acute type A aortic dissection between April 2014 and July 2022 were included in this study. We evaluated the renal artery-level dissected aortic morphology and classified the study population into 2 groups: the ventral (those with the true lumen located on the ventral side) and the dorsal (other patients not assigned to the ventral group) groups, based on the location of the true lumen. Aortic dilation was defined as thoraco-abdominal aortic expansion ≥5 mm on 1-year postoperative computed tomography images. We examined 49 surgical patients who were assigned to the ventral (n = 22) and dorsal (n = 27) groups. The number of patients with ≥5 mm thoraco-abdominal aortic dilation after the operation was significantly higher in the ventral group than in the dorsal group (90.9% vs 51.9%, P = 0.009). The multivariable logistic regression analysis showed that the ventral type was an independent prognostic factor for thoraco-abdominal aortic dilation after the operation (odds ratio, 6.01; 95% confidence interval, 1.56-23.77; P = 0.009). The location of the true lumen of the abdominal aorta in acute type A aortic dissection may be a prognostic factor for thoraco-abdominal aortic dilation after surgical repair.

Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note

BackgroundShoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model.MethodsWe developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration.ResultsThe 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels.ConclusionsThe findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

Longitudinal Study on Pre- and Post-Operation CT Imaging for Predicting Pedicle Screw Loosening in Patients with Lumbar Degenerative Disease.

We conducted a longitudinal study to examine the predictive role of risk factors in the occurrence of pedicle screw loosening, assessed through pre- and post-operative computed tomography (CT) scans. A total of 103 patients with degenerative lumbar disease who had undergone L4/5 pedicle screw fixation (involving 412 screws) were included in this study. They were subsequently categorized into two groups-the "loosening group" and the "non-loosening group". The axial and sagittal angles of the screw trajectory in pre- and post-operative CT images were measured, and the deviation angles were computed. Additionally, measurements were taken of the Hounsfield unit (HU) within the screw entry point area, the pedicle, and the vertebral body in preoperative CT images. Logistic regression analysis was employed to ascertain the risk factors influencing the occurrence of screw loosening. Elderly patients who experienced screw loosening tended to have bilateral screw issues at the L5 level (p < 0.005). The HU of the pedicle (p < 0.001), age (p < 0.001), and the axial deviation angle (p = 0.014) were identified as independent factors predicting screw loosening. Additionally, when HU of the pedicle < 126.5 or age ≥ 53.5 years, the axial deviation angle was found to be smaller in the group experiencing screw loosening (p = 0.018 and p = 0.019). Loosening of screws positioned at L5 was found to be more prevalent in elderly patients, particularly exhibiting a bilateral occurrence. Independent predictors of this phenomenon included a low HU value in the pedicle, advanced age in patients, and a substantial axial deviation angle. In the case of elderly patients with a low HU value in the pedicle, a reduced axial surgical deflection was necessitated to prevent the occurrence of screw loosening.

Free-hand technique of C7 pedicle screw insertion using a simply defined entry point without fluoroscopic guidance for cervical spondylotic myelopathy patients with C3 to C6 instrumented by lateral mass screws: a retrospective cohort study

BackgroundNowadays, both lateral mass screw (LMS) and pedicle screw were effective instrumentation for posterior stabilization of cervical spine. This study aims to evaluate the feasibility of a new free-hand technique of C7 pedicle screw insertion without fluoroscopic guidance for cervical spondylotic myelopathy (CSM) patients with C3 to C6 instrumented by lateral mass screws.MethodsA total of 53 CSM patients underwent lateral mass screws instrumentation at C3 to C6 levels and pedicle screw instrumentation at C7 level were included. The preoperative 3-dimenional computed tomography (CT) reconstruction images of cervical spine were used to determine 2 different C7 pedicle screw trajectories. Trajectory A passed through the axis of the C7 pedicle while trajectory B selected the midpoint of the base of C7 superior facet as the entry point. All these 53 patients had the C7 pedicle screw inserted through trajectory B by free-hand without fluoroscopic guidance and the postoperative CT images were obtained to evaluate the accuracy of C7 pedicle screw insertion.ResultsTrajectory B had smaller transverse angle, smaller screw length, and smaller screw width but both similar sagittal angle and similar pedicle height when compared with trajectory A. A total of 106 pedicle screws were inserted at C7 through trajectory B and only 8 screws were displaced with the accuracy of screw placement as high as 92.5%.ConclusionIn CSM patients with C3 to C6 instrumented by LMS, using trajectory B for C7 pedicle screw insertion is easy to both identify the entry point and facilitate the rod insertion.

Patient-Specific Implant Customization for Treatment of Internal Orbital Fractures Using Office-Based Three-Dimensional Printing.

Three-dimensional (3D) modeling technology aids the reconstructive surgeon in designing and tailoring individualized implants for the reconstruction of complex craniofacial fractures. Three-dimensional modeling and printing have traditionally been outsourced to commercial vendors but can now be incorporated into both private and academic craniomaxillofacial practices. The goal of this report is to present a low-cost, standardized office-based workflow for restoring bony orbital volume in traumatic orbital fractures. Patients with internal orbital fractures requiring open repair were identified. After the virtual 3D models were created by iPlan 3.0 Cranial CMF software (Brainlab), the models were printed using an office-based 3D printer to shape and modify orbital plates to correctly fit the fracture defect. The accuracy of the anatomic reduction and the restored bony orbital volume measurements were determined using postoperative computed tomography images and iPlan software. Nine patients fulfilled the inclusion criteria: 8 patients had unilateral fractures and 1 patient had bilateral fractures. Average image processing and print time were 1.5 hours and 3 hours, respectively. The cost of the 3D printer was $2500 and the average material cost to print a single orbital model was $2. When compared with the uninjured side, the mean preoperative orbital volume increase and percent difference were 2.7 ± 1.3mL and 10.9 ± 5.3%, respectively. Postoperative absolute volume and percent volume difference between the orbits were -0.2 ± 0.4mL and -0.8 ± 1.7%, respectively. Office-based 3D printing can be routinely used in the repair of internal orbital fractures in an efficient and cost-effective manner to design the implant with satisfactory patient outcomes.

Pedicle screw placement accuracy in robot-assisted versus image-guided freehand surgery of thoraco-lumbar spine (ROBARTHRODESE): study protocol for a single-centre randomized controlled trial

BackgroundRobotic spinal surgery may result in better pedicle screw placement accuracy, and reduction in radiation exposure and length of stay, compared to freehand surgery. The purpose of this randomized controlled trial (RCT) is to compare screw placement accuracy of robot-assisted surgery with integrated 3D computer-assisted navigation versus freehand surgery with 2D fluoroscopy for arthrodesis of the thoraco-lumbar spine.MethodsThis is a single-centre evaluator-blinded RCT with a 1:1 allocation ratio. Participants (n = 300) will be randomized into two groups, robot-assisted (Mazor X Stealth Edition) versus freehand, after stratification based on the planned number of pedicle screws needed for surgery. The primary outcome is the proportion of pedicle screws placed with grade A accuracy (Gertzbein-Robbins classification) on postoperative computed tomography images. The secondary outcomes are intervention time, operation room occupancy time, length of stay, estimated blood loss, surgeon’s radiation exposure, screw fracture/loosening, superior-level facet joint violation, complication rate, reoperation rate on the same level or one level above, functional and clinical outcomes (Oswestry Disability Index, pain, Hospital Anxiety and Depression Scale, sensory and motor status) and cost-utility analysis.DiscussionThis RCT will provide insight into whether robot-assisted surgery with the newest generation spinal robot yields better pedicle screw placement accuracy than freehand surgery. Potential benefits of robot-assisted surgery include lower complication and revision rates, shorter length of stay, lower radiation exposure and reduction of economic cost of the overall care.Trial registrationClinicalTrials.gov NCT05553028. Registered on September 23, 2022

Brain Shift during Staged Deep Brain Stimulation for Movement Disorders

Introduction: Deep brain stimulation (DBS) is a routine neurosurgical procedure utilized to treat various movement disorders including Parkinson’s disease (PD), essential tremor (ET), and dystonia. Treatment efficacy is dependent on stereotactic accuracy of lead placement into the deep brain target of interest. However, brain shift attributed to pneumocephalus can introduce unpredictable inaccuracies during DBS lead placement. This study aimed to determine whether intracranial air is associated with brain shift in patients undergoing staged DBS surgery. Methods: We retrospectively evaluated 46 patients who underwent staged DBS surgery for PD, ET, and dystonia. Due to the staged nature of DBS surgery at our institution, the first electrode placement is used as a concrete fiducial marker for movement in the target location. Postoperative computed tomography (CT) images after the first electrode implantation, as well as preoperative, and postoperative CT images after the second electrode implantation were collected. Images were analyzed in stereotactic targeting software (BrainLab); intracranial air was manually segmented, and electrode shift was measured in the x, y, and z plane, as well as a Euclidian distance on each set of merged CT scans. A Pearson correlation analysis was used to determine the relationship between intracranial air and brain shift, and student’s t test was used to compare means between patients with and without radiographic evidence of intracranial air. Results: Thirty-six patients had pneumocephalus after the first electrode implantation, while 35 had pneumocephalus after the second electrode implantation. Accumulation of intracranial air following the first electrode implantation (4.49 ± 6.05 cm³) was significantly correlated with brain shift along the y axis (0.04 ± 0.35 mm; r (34) = 0.36; p = 0.03), as well as the Euclidean distance of deviation (0.57 ± 0.33 mm; r (34) = 0.33; p = 0.05) indicating statistically significant shift on the ipsilateral side. However, there was no significant correlation between intracranial air and brain shift following the second electrode implantation, suggesting contralateral shift is minimal. Furthermore, there was no significant difference in brain shift between patients with and without radiographic evidence of intracranial air following both electrode implantation surgeries. Conclusion: Despite observing volumes as high as 22.0 cm³ in patients with radiographic evidence of pneumocephalus, there was no significant difference in brain shift when compared to patients without pneumocephalus. Furthermore, the mean magnitude of brain shift was <1.0 mm regardless of whether pneumocephalus was presenting, suggesting that intracranial air accumulation may not produce clinical significant brain shift in our patients.

Remission of Nonalcoholic Fatty Liver Disease After Radical Surgery in Patients with Colorectal Cancer: A Single-Center Retrospective Study.

Purpose: The purpose of this study was to investigate the relationship between remission of nonalcoholic fatty liver disease (NAFLD) and radical surgery for colorectal cancer (CRC) patients. Methods: From January 2014 to December 2021, data of patients with concurrent CRC and NAFLD who underwent radical surgery in a single-center hospital were retrospectively collected. NAFLD was defined as a mean computed tomography (CT) liver attenuation value of <40 Hounsfield units (HUs). Comparison of preoperative and 1-year postoperative CT images was performed to evaluate the change of NAFLD. Multivariate logistic regression analysis was performed to identify independent predictive factors for NAFLD remission. The Kaplan-Meier method was used to estimate overall survival (OS) and disease-free survival (DFS) between the remission group and no remission group. Results: In this study, a total of 55 eligible patients were included. The remission group had 33 (60.0%) patients and the no remission group had 22 (40.0%) patients. The mean preoperative weight was 66.1 ± 9.9 kg. The mean preoperative body mass index (BMI) was 25.4 ± 2.5 kg/m2. We found that the average weight was significantly decreased (P < 0.01), average BMI was significantly decreased (P < 0.01), and HU score was significantly increased (P < 0.01). By comparing baseline characteristics between the remission group and no remission group, we found that the remission group exhibited larger tumor sizes (P = 0.036) than the no remission group. In the multivariate logistic regression analysis, we found that weight change was a predictor for NAFLD (odds ratio = 0.764, 95% confidence interval = 0.618-0.944, P = 0.013). We did not find any statistically significant differences in OS (P = 0.182) or DFS (P = 0.248) between the remission group and no remission group. Conclusions: The NAFLD remission rate reached 60.0% for CRC patients 1 year after radical surgery. In addition, we found that weight change was a predictor of NAFLD remission.

Computed Tomography Versus Simple Radiography for Detecting and Classifying Heterotopic Ossification after Reverse Shoulder Arthroplasty.

Heterotopic ossification (HO) is difficult to characterize and classify on simple radiographs. Therefore, we attempted to evaluate intraobserver and interobserver reliability of simple radiography and computed tomography (CT) for detecting and classifying HO after reverse shoulder arthroplasty (RSA). It was hypothesized that CT would provide more reliable results than simple radiography. This retrospective study reviewed 30 patients who underwent RSA performed by a single surgeon. Patients were included if they had both postoperative simple radiographs and CT images taken immediately after surgery and at 1 year after surgery and if they had completed clinical assessment at least 1 year after surgery. We first evaluated the intraobserver and interobserver reliability for the detection of the presence of HO and Modified Brooker's classification both on simple radiographs and CT scans with the use of Kappa statistics. Then, we analyzed the correlation of HO observed in simple radiographs and CT scans with clinical outcomes. All radiographic evaluations were performed by 2 independent reviewers in random orders with 3 weeks of intervals. The intraobserver reliability outcomes of both reviewers in simple radiography and CT were almost perfect or perfect for the detection of HO and classification. However, CT images improved the interobserver reliability for the detection of HO (kappa value for simple radiographs [KXR] = 0.6018 and kappa value for CT [KCT] = 0.8316) and classification (KXR = 0.5300 and KCT = 0.6964). At a mean follow-up of 25 months (range, 12-54 months), clinical scores were not significantly different according to the presence of HO based on simple radiographs. However, when CT images were used, the University of California, Los Angeles score and physical component score of short-form 36-item health survey were significantly lower in patients with HO than in patients without HO (27.0 vs. 30.4, p = 0.045 and 57.6 vs. 70.7, p = 0.034, respectively). Both simple radiography and CT provided excellent intraobserver reliability for detecting and classifying HO after RSA. Compared to simple radiography, CT tended to improve interobserver reliability and defined the presence and severity of HO more clearly.

Anomalous origin of the right coronary artery originating from the pulmonary trunk: pre- and postoperative computed tomography images and virtual reality reconstructions.

Anomalous origin of the right coronary artery originating from the pulmonary trunk: pre- and postoperative computed tomography images and virtual reality reconstructions.