Postoperative Computed Tomography Research Articles

Robotic Pedicle Screw Placement with 3D MRI Registration: Moving Towards Radiation Free Robotic Spine Surgery

BACKGROUND CONTEXTPreoperative imaging for lumbar spine surgery often includes magnetic resonance imaging (MRI) for soft tissues and computer tomography (CT) for bony detail. While CT scans expose patients to ionizing radiation, whereas MRI scans do not. Emerging MRI techniques allow CT-like three-dimensional (3D) visualization of bony structures, potentially removing the need for ionizing radiation from CT scans. PURPOSEThis study aims to explore the accuracy of robot-assisted lumbar pedicle screw placement based on preoperative CT-like 3D MRI as the data source for robotic registration. STUDY DESIGNHuman cadaveric study. METHODS: CT-like 3D MRI scans of the lumbar spine were acquired in ten human cadavers. A robotic navigation platform was used to plan and navigate pedicle screw placement based on the CT-like 3D MRI. Postoperative CT scans assessed the accuracy of screw positioning compared to preoperative planning based on the Gertzbein-Robbins scale (GRS) and by direct measurement (mm). RESULTSA total of 100 lumbar pedicle screws were robotically placed in ten cadavers (L1 through L5 bilaterally) based on CT-like 3D MRI. On postoperative CT evaluation, 99.0% of the positioned screws achieved an acceptable grade on the GRS (Grade A: n = 89 or Grade B: n = 10), with 89.0% classified as Grade A and 10.0% as Grade B. Meaning that 89.0% of screws were fully contained within the pedicle (GRS A), and 10% had a minor cortical breach <2mm (GRS B). The median deviation from the planned trajectory was 0.2 mm (axial IQR: 0.1 to 0.5 mm; sagittal: IQR: 0.1 to 0.4 mm), in both axial and sagittal planes. CONCLUSIONThis study showed that image registration of CT-like 3D MRI for robotic-assisted spine surgery is technically feasible and that accurate pedicle screw placement can be achieved without preoperative CT. Each CT-like 3D MRI was successfully registered for robotic navigation. CLINICAL SIGNIFICANCEThe results suggest that CT-like 3D MRI has the potential to be a radiation-free alternative for preoperative planning and navigation in lumbar spine instrumentation procedures.

Interobserver variability of clinical target volume delineation in patients undergoing breast-conserving surgery without surgical clips: a pilot study on preoperative magnetic resonance simulation

BackgroundIn patients undergoing breast-conserving therapy without surgical clip implantation, the accuracy of tumor bed identification and the consistency of clinical target volume (CTV) delineation under computed tomography (CT) simulation remain suboptimal. This study aimed to investigate the feasibility of implementing preoperative magnetic resonance (MR) simulation on delineations by assessing interobserver variability (IOV).MethodsPreoperative MR and postoperative CT simulations were performed in patients who underwent breast-conserving surgery with no surgical clips implanted. Custom immobilization pads were used to ensure the same supine position. Three radiation oncologists independently delineated the CTV of tumor bed on the images acquired from MR and CT simulation registration and CT simulation alone. Cavity visualization score (CVS) was assigned to each patient based on the clarity of the tumor bed on CT simulation images. IOV was indicated by generalized conformity index (CIgen), denoted as CIgen−CT and CIgen−MR/CT, and the distance between the centroid of mass (dCOM), denoted as dCOMCT and dCOMMR/CT. The variation of IOV in different CVS subgroups was analyzed.ResultsA total of 10 patients were enrolled in this study. The median and interquartile range (IQR) of maximum pathological diameter of the tumors in all patients were 1.55 (0.80–1.92) cm. No statistical significance was found between the volumes of CTVs on CT simulation and on MR/CT simulation registration images (p = 0.387). CIgen−MR/CT was significantly larger than CIgen−CT (p = 0.005). dCOMMR/CT was significantly smaller than dCOMCT (p = 0.037). The median and IQR of CVS in all patients were 2.34 (2.00–3.08). The difference of CIgen between CIgen−MR/CT and CIgen−CT was larger in the low CVS group (p = 0.016). The difference of dCOM showed a decreasing trend when CVS was lower, although it did not reach statistical significance (p = 0.095).ConclusionsFor patients who underwent breast-conserving surgery without surgical clip implantation, the use of preoperative MR simulation in delineating the CTV of tumor bed decreased the IOV among observers. The consistency of tumor bed identification was improved especially in cases where the margins of tumor bed were challenging to visualize on CT simulation images. The study findings offer potential benefits in reducing local recurrence and minimizing tissue irritation in the surrounding areas. Future investigation in a larger patient cohort to validate our results is warranted.

Computed tomography and structured light imaging guided orthopedic navigation puncture system: effective reduction of intraoperative image drift and mismatch.

Image-guided surgical navigation systems are widely regarded as the benchmark for computer-assisted surgical robotic platforms, yet a persistent challenge remains in addressing intraoperative image drift and mismatch. It can significantly impact the accuracy and precision of surgical procedures. Therefore, further research and development are necessary to mitigate this issue and enhance the overall performance of these advanced surgical platforms. The primary objective is to improve the precision of image guided puncture navigation systems by developing a computed tomography (CT) and structured light imaging (SLI) based navigation system. Furthermore, we also aim to quantifying and visualize intraoperative image drift and mismatch in real time and provide feedback to surgeons, ensuring that surgical procedures are executed with accuracy and reliability. A CT-SLI guided orthopedic navigation puncture system was developed. Polymer bandages are employed to pressurize, plasticize, immobilize and toughen the surface of a specimen for surgical operations. Preoperative CT images of the specimen are acquired, a 3D navigation map is reconstructed and a puncture path planned accordingly. During surgery, an SLI module captures and reconstructs the 3D surfaces of both the specimen and a guiding tube for the puncture needle. The SLI reconstructed 3D surface of the specimen is matched to the CT navigation map via two-step point cloud registrations, while the SLI reconstructed 3D surface of the guiding tube is fitted by a cylindrical model, which is in turn aligned with the planned puncture path. The proposed system has been tested and evaluated using 20 formalin-soaked lower limb cadaver specimens preserved at a local hospital. The proposed method achieved image registration RMS errors of 0.576 ± 0.146 mm and 0.407 ± 0.234 mm between preoperative CT and intraoperative SLI surface models and between preoperative and postoperative CT surface models. In addition, preoperative and postoperative specimen surface and skeletal drifts were 0.033 ± 0.272 mm and 0.235 ± 0.197 mm respectively. The results indicate that the proposed method is effective in reducing intraoperative image drift and mismatch. The system also visualizes intraoperative image drift and mismatch, and provides real time visual feedback to surgeons.

Does More Invasive Surgery Result in Higher Patient Satisfaction? A Long-Term Follow-Up of 136 Zygomaticomaxillary Complex Fractures

Study Design Retrospective with follow-up. Objective To evaluate the long-term satisfaction of surgically treated patients with zygomaticomaxillary complex (ZMC) fractures in relation to the use of internal fixation, number of fixation points, and orbital floor (OF) reconstruction. Secondary objectives were to describe the use of antibiotics and post-operative infections. Methods Patients with unilateral ZMC fractures between 2007-2018 and treatment with either open reduction and internal fixation (ORIF) or closed reduction (CR) were identified from medical records and invited to follow-ups between 2018-2020. Patients were examined, photographed, and completed a questionnaire. A review panel of 3 experienced surgeons evaluated photographs and computed tomography (CT) scans pre- and post-surgery. Results The study sample consisted of 136 patients (108 ORIF, 28 CR) with a median follow-up time of 76 months. Patient satisfaction of surgical outcome was high (97.8%), with no significant differences in relation to the use of internal fixation, number of fixation points, or OF reconstruction. Dissatisfaction was primarily related to hypoesthesia. On post-operative CT scans, malar asymmetry was more often predicted in patients with 1-point fixations. On questionnaires and photographs, malar asymmetry was more common in patients with 3-point fixations. Prophylactic antibiotics had no effect on the rate of post-operative infections. Conclusions Patient satisfaction was not influenced by internal fixation, number of fixation points, or OF reconstruction. Selected ZMC fractures can be treated with less invasive approaches. Caution should be observed when predicting long-term malar asymmetry on post-operative CT scans. The findings of this study highlight the importance of a rational and ethical use of surgery.

Delayed Maxillary Reconstruction with Free Osteocutaneous Fibula Flap Using CAD-CAM Technology

Abstract Background Maxillary reconstruction poses unique challenges for the reconstructive surgeon because of the complex three-dimensional (3D) anatomy of the maxilla. Undertaking this endeavor on secondary reconstruction makes it more difficult due to problems in recreating the true defect. This study is an attempt to demonstrate the role of virtual surgical planning (VSP), 3D printing, and mock surgery in reconstructing such defects using free fibula flaps. Materials and Methods This was a prospective study involving 10 patients of maxillary defects who underwent delayed reconstruction with a free fibula flap. The planning was done preoperatively using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. A mock surgery with 3D printed models was done before the surgery. After the surgery, the accuracy results were obtained by overlapping and measuring fixed point distances between preoperative virtual planning and postoperative computed tomography (CT) scan data. Results and Discussion Nine patients underwent successful reconstruction and were satisfied with the outcome. One patient had flap loss. The mean shift along the horizontal, vertical, and 3D axes was less than 5 mm between the preoperative virtual planning and postoperative CT scan data, indicating accurate reconstruction. We also suggest strategies for soft-tissue and bony inset including inferolateral pedicle origin, anteriorly facing lateral fibular surface, and two bony struts for the alveolus. Conclusion VSP and CAD-CAM technology in maxillary reconstructions help achieve an anatomically accurate neo-maxilla. The addition of mock surgery to the routine and the use of cutting guide avoid unpredictability and reduce the need for adaptation activities on the operating table. CAD-CAM technology despite its limitations is invaluable in maxillary reconstruction and is an important tool for a reconstructive plastic surgeon.

High Rate of Return to Sport in Contact and Collision Athletes After Arthroscopic Latarjet With Cortical Button Fixation

Background: Contact and collision athletes face a higher risk of recurrent anterior shoulder instability after surgical stabilization. The Latarjet procedure is often preferred given the high incidence of bony lesions. However, this stabilizing procedure, performed either open or arthroscopically, is met with concerns regarding complications and revision surgery rates. Purpose: To evaluate the return to sport (RTS) and assess complication and instability recurrence rates in contact/collision athletes undergoing the arthroscopic Latarjet procedure using a guided technique with suture buttons for coracoid fixations. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was conducted on contact/collision athletes who underwent the arthroscopic Latarjet procedure for recurrent anterior shoulder instability between January 2011 and March 2018. All patients were operated on arthroscopically using glenoid and coracoid guides and suture button fixation of the transferred coracoid. RTS was defined as the patient being able to participate in his or her activity without any restriction postoperatively. Two independent observers assessed patients using postoperative computed tomography (CT) scans to evaluate coracoid positioning and healing. A multivariate analysis was performed to identify predictive factors associated with persistent apprehension. A group comparison was performed to assess RTS failure risk factors. Results: In 136 contact/collision athletes (mean age, 25 ± 7 years), 93% were satisfied, and 98% achieved shoulder stability at a mean follow-up of 60 months (range, 24-117 months). No suture button–related complications or neurovascular issues were reported. Overall, 82% (112/136) returned to contact/collision sports. The mean time to RTS was 5.3 ± 1.2 months (range, 3-7.3 months). In a CT study performed 2 weeks after surgery, 87% (118/136) of bone grafts were positioned below the equator and 93% (126/136) were flush to the glenoid surface. At the 6-month postoperative CT examination, complete bone block healing was achieved in 84% (114/136). On clinical examination at the latest follow-up, 36 patients (26%) reported some anterior apprehension on testing. On multivariate analysis, patients with severe humeral bone defects (medium to large Hill-Sachs lesions, Calandra grade 2 or 3) had a higher risk of postoperative persistent apprehension. On group comparison, a visual analog scale score >3 and persistent anterior apprehension were found to be associated with failure of RTS. Conclusion: The arthroscopic Latarjet procedure with suture button fixation allowed 82% of athletes with recurrent anterior shoulder instability to return to contact or collision sports. Patients with severe humeral bone defects have a higher risk of persistent anterior apprehension and decreased RTS. The arthroscopic-guided procedure with suture button fixation is safe; accurate, with a high rate of anatomic graft positioning and healing; and reliable, with a low recurrence rate.

Risk factors for proximal and distal aortic events after type A acute aortic dissection.

Type A acute aortic dissection (TAAAD) is a life-threatening condition often requiring emergency surgery, with approximately 30% of patients needing reoperation. This study aimed to identify predictors of long-term aortic events from early postoperative computed tomography (CT) examinations. A total of 336 cases underwent TAAAD surgery at two institutions between 2002 and 2018. Of these, 302 patients received CT examinations immediately after initial TAAAD surgery. Predictors of aortic events were evaluated from these early postoperative CT exams. Aortic events were defined as any events involving aortic-related death, open surgery, reoperation, endovascular stenting, or thoracic aorta diameter enlargement to ≥ 55mm. Excluding 34 in-hospital deaths (10.1%; 34/336), the 1-, 5-, and 10-year actuarial survival rates after primary TAAAD surgery were 98.2%, 88.6%, and 81.7%, respectively. Over a mean follow-up period of 7.4 ± 5.1years, 67 aortic events (proximal: 19, distal: 45, both: 3) were observed. Freedom from proximal aortic events was 98.6%, 93.9%, and 85.2% at 1, 5, and 10years, respectively. Proximal anastomosis new entry was identified as a significant risk factor for aortic events, with a 92% vs. 42% incidence at 10years (p < 0.001). Freedom from distal aortic events was 99.6%, 84.5%, and 67.2% at 1, 5, and 10years, respectively. A false/true area ratio greater than 1 and distal anastomosis new entry were significant risk factors for aortic events (low-risk group: 83.3% vs. high-risk group: 42.3% at 10years, p < 0.001). Detailed analysis of early postoperative CT scans following primary TAAAD surgery may help identify predictors of subsequent aortic events, potentially improving long-term patient management and outcomes.

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.

Sealing Zone Failure Decreases the Long Term Durability of Endovascular Aneurysm Repair

Endovascular aneurysm repair (EVAR) has higher long term aneurysm related mortality compared with open surgery, mainly due to aneurysm rupture. Loss of stent graft-vessel apposition at the EVAR sealing zones is a potential cause of post-EVAR rupture. This study aimed to investigate sealing zone failure and its relation to post-EVAR rupture. This was a retrospective structured review of pre-operative and post-operative computed tomography (CT) scans of 399 consecutive patients treated with standard bifurcated EVAR. The primary outcome was total loss of seal at last post-operative CT. Secondary outcomes were partial loss of seal, standard follow up detection, post-EVAR rupture, aneurysm sac development, and endoleaks. During a median follow up of 5.3 years, total and partial loss of seal occurred in 85 (21.3%) and 78 (19.5%) patients, respectively. Initial mean sealing zone lengths were within current recommendations but decreased over time, mainly due to vessel dilatation. Mean proximal sealing length at one month CT was 15.5 ± 10.5 mm (95% confidence interval [CI] 12.6 - 18.5 mm) in the group with total loss of seal, 14.3 ± 6.9 mm (95% CI 12.2 - 16.4 mm) with partial loss of seal, and 23.2 ± 7.4 mm (95% CI 22.3 - 24.0 mm) with preserved seal through follow up (p < .001). Mean iliac sealing lengths were 22.4 ± 12.1 mm (95% CI 18.9 - 25.8 mm) if total loss and 21.8 ± 10.0 mm (95% CI 19.6 - 24.0 mm) if partial loss of seal vs. 34.7 ± 12.4 mm (95% CI 33.8 - 35.7 mm) if preserved seal. Larger vessel diameters were associated with loss of seal both in proximal and distal sealing zones. During the study period, 13 post-EVAR ruptures occurred, all preceded by CT findings of total (n = 7) or partial (n = 6) loss of seal. Aneurysm sac expansion was seen in 40% of patients with total loss of seal, 18% with partial loss of seal, and 6.6% with preserved seal. Loss of seal after EVAR is frequent and associated with post-EVAR rupture. Increased recommended sealing zones lengths and focus on sealing zones in surveillance may reduce post-EVAR ruptures and aneurysm related mortality.

Clinical and radiological outcome of extended lateral approach via epicondyle osteotomy in complex lateral tibia plateau fractures involving the central and postero-lateral segments

IntroductionThe purpose of this study was to evaluate the clinical and radiological results of complex lateral tibial plateau fractures involving the central segments of the lateral tibial plateau. It was hypothesized that an extended lateral approach by using the lateral epicondyle osteotomy improves the rate of malreduction and yields to good and excellent clinical results at a mid-term follow-up. MethodsThis retrospective case series conducted at two centers evaluated complex lateral tibial plateau fractures treated with an extended lateral approach by lateral epicondyle osteotomy. Fractures were classified according to the AO/OTA and 10-segment classification, with only B/C type fractures involving the antero-latero-central (ALC) and postero-latero-central (PLC)/postero-latero-lateral (PLL) segments. Postoperative computer tomography scans were used to assess the quality of reduction. Clinical outcomes and postoperative complications were evaluated with a minimum follow-up of 2 years. ResultsSixty-five patients (mean age: 47.7 ± 11.5 years) were included, with an average follow-up of 51.9 ± 3.6 months. Radiological outcomes revealed a postoperative fracture step at the ALC/PLC crossing of 0.8 ± 1.1 mm, at the PLC/PLL crossing of 0.4 ± 1.1 mm, and a fracture gap of 1.8 ± 4.0 mm, yielding a Rasmussen Score of 15.1 ± 3.2. No significant differences among type B and C fractures were identified. No case of nonunion of the lateral epicondyle osteotomy was recorded. The mean Knee injury and Osteoarthritis Outcome Score was 80.4 ± 16.2 (type B 85.6 ± 11.9 vs. type C 76.1 ± 18.4, p < 0.05), Lysholm score was 83.4 ± 17.1 (B 89 ± 11.3 vs. C 78.7 ± 20.1, p < 0.05) and International Knee Documentation Committee score was 69.9 ± 18.8 (type B 76.5 ± 15.7 vs. type C 64.3 ± 20.1, p < 0.05). Early complication rate requiring surgical revision due to malreduction or infection were 7 %. None of the patients reported about subjective lateral knee instability at the time of clinical follow-up. ConclusionThe extended lateral approach with lateral epicondyle osteotomy demonstrated excellent radiological alignment and favorable mid-term clinical outcomes. An overall low complication rate was recorded. Notably, long-term revisions due to lateral instability were absent, indicating the safety and efficacy of lateral epicondyle osteotomy as an operative technique.

Accuracy of Implant Placement Based on Three-Dimensional Preoperative Planning in Total Elbow Arthroplasty.

Background: Accurate implant placement in the optimal position is important to obtain favourable clinical outcomes and prevent complications in total joint arthroplasty. We aimed to assess the accuracy of implant placement based on three-dimensional (3D) preoperative planning for unlinked total elbow arthroplasty (TEA) and to clarify the effect of implant placement on clinical outcomes. Methods: This study included 20 patients (22 elbows, 17 with rheumatoid arthritis and 5 with osteoarthritis, with a mean follow-up period of 47 months) who underwent TEA with an unlinked-type implant after computed tomography (CT)-based 3D preoperative planning. Implant placement was planned preoperatively and several parameters were set to reflect it intraoperatively. TEA was performed based on the plan, and postoperative CT was conducted to evaluate differences in implant placement by comparing the preoperative plan and postoperative implant placement. Furthermore, we evaluated the relationship between implant placement differences and postoperative clinical outcomes, including range of motion, Visual Analogue Scale, Mayo Elbow Performance Score 1 year after surgery and complications at the last follow-up. Results: The mean absolute translation was within 2 mm, the mean absolute tilt was within 4°, the mean absolute rotation of the humeral component was within 4° and the mean absolute rotation of the ulnar component was 10.2° ± 6.8°. In the ulnar components, 15/22 (68%) cases were externally rotated, and the mean external rotation was 7.1° ± 10.2°. We defined the absolute ulnar component's rotational difference of more than 10° as a 'malrotation' group (n = 8) and 10° or less as a 'control' group (n = 14). We compared the clinical outcomes between both groups, however, no significant differences were observed in clinical outcomes and complications. Conclusions: We observed notable malrotation in the postoperative positioning of the ulnar component. Intraoperative support devices may be necessary to accurately reproduce the preoperative plan in the surgical field. Level of Evidence: Level IV (Therapeutic).

Mandibular reconstruction after post-traumatic complex fracture: Comparison analysis between traditional and virtually planned surgery

BackgroundJaw reconstruction after complex post-traumatic fracture is still a challenge for surgeons using traditional surgery. Virtual surgical planning has proven to be a valid tool for managing these fractures. The aim of this study is to quantitatively evaluate the VSP effectiveness compared to traditional surgery in the management of complex mandibular fractures. Methods30 patients with diagnosis of complex mandibular fracture were enrolled and divided in two groups: Group A (virtually planned surgery), The plate was pre-modeled and employed during the surgery; Group B (traditional surgery), the plate was shaped directly during the surgery. Virtually planned and post-operative Computer Tomography were after compared for both the groups to highlight discrepancies in mm. ResultsFracture surgical reduction was successful without intraoperative complications. In Group A, all the mean discrepancies’ values were <1 mm while in Group B the values were included between 1.36 and 1.94 mm. The mean operative time was 69 min for Group A, while 106 min for Group B. ConclusionsFracture virtual reduction and realization of pre-modeled plate are able to guarantee a more anatomically correct reduction and a decrease in operating times. These outcomes translate into a decrease in both short and long-term complications.

Clinical validation of artificial intelligence-based preoperative virtual reduction for Neer 3- or 4-part proximal humerus fractures

BackgroundIf reduction images of fractures can be provided in advance with artificial-intelligence (AI)-based technology, it can assist with preoperative surgical planning. Recently, we developed the AI-based preoperative virtual reduction model for orthopedic trauma, which can provide an automatic segmentation and reduction of fractured fragments. The purpose of this study was to validate a quality of reduction model of Neer 3- or 4-part proximal humerus fractures established by AI-based technology.MethodsTo develop the AI-based preoperative virtual reduction model, deep learning performed the segmentation of fracture fragments, and a Monte Carlo simulation completed the virtual reduction to determine the best model. A total of 20 pre/postoperative three-dimensional computed tomography (CT) scans of proximal humerus fracture were prepared. The preoperative CT scans were employed as the input of AI-based automated reduction (AI-R) to deduce the reduction models of fracture fragments, meanwhile, the manual reduction (MR) was conducted using the same CT images. Dice similarity coefficient (DSC) and intersection over union (IoU) between the reduction model from the AI-R/MR and postoperative CT scans were evaluated. Working times were compared between the two groups. Clinical validity agreement (CVA) and reduction quality score (RQS) were investigated for clinical validation outcomes by 20 orthopedic surgeons.ResultsThe mean DSC and IoU were better when using AI-R that when using MR (0.78 ± 0.13 vs. 0.69 ± 0.16, p < 0.001 and 0.65 ± 0.16 vs. 0.55 ± 0.18, p < 0.001, respectively). The working time of AI-R was, on average, 1.41% of that of MR. The mean CVA of all cases was 81%±14.7% (AI-R, 82.25%±14.27%; MR, 76.75%±14.17%, p = 0.06). The mean RQS was significantly higher when AI-R compared with MR was used (91.47 ± 1.12 vs. 89.30 ± 1.62, p = 0.045).ConclusionThe AI-based preoperative virtual reduction model showed good performance in the reduction model in proximal humerus fractures with faster working times. Beyond diagnosis, classification, and outcome prediction, the AI-based technology can change the paradigm of preoperative surgical planning in orthopedic surgery.Level of evidenceLevel IV.

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.

Intra-articular fracture reduction: a comparative observational study of clinical results after the surgical treatment of distal radius fractures

Purpose: This study compared the outcomes of intra-articular fracture reduction for distal radius fractures. Methods: Among 180 patients who underwent open reduction and plate fixation, the exclusion criteria were as follows: non-acute fracture (&gt;1 month), an accompanying ulnar neck fracture, a distal ulnar fracture requiring fixation, fixation through the dorsal approach, other accompanying hand fractures, the absence of preoperative or postoperative computed tomography (CT), and follow-up for &lt;1 year. Intra-articular fractures were evaluated through CT. Forty-eight patients with intra-articular fractures were studied. Displaced intra-articular fractures were defined as: (1) articular step-off ≥1 mm, (2) fracture gap ≥2 mm, or (3) gross incongruence. Reduction was classified as good (n=23) or poor (n=25) based on postoperative CT. The pain visual analogue scale (pVAS), the quick Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and range of motion of the wrist joint were compared between both groups.Results: No significant between-group differences were found in the preoperative demographic data and the postoperative pVAS and quick DASH scores (pVAS: 0.6 vs. 0.8 and quick DASH: 9.4 vs. 10.2 in the good vs. poor reduction groups, respectively). However, the flexion-extension arc was significantly restricted in the poor reduction group (162° in the good reduction group vs. 146° in the poor reduction group, p&lt;0.001).Conclusion: The reduction of the articular surface was not related to pain and functional results at the mid-term follow-up after the surgical treatment of intra-articular distal radius fractures. However, insufficient fracture reduction affected the postoperative range of motion.

MIXED-REALITY GUIDANCE FOR PELVIC OSTEOTOMY AND ACETABULAR REALIGNMENT: PROOF OF CONCEPT

Mixed Reality has the potential to improve accuracy and reduce required dissection for the performance of peri-acetabular osteotomy. The current work assesses initial proof of concept of MR guidance for PAO.A PAO planning module, based on preoperative computed tomography (CT) imaging, allows for the planning of PAO cut planes and repositioning of the acetabular fragment. 3D files (holograms) of the cut planes and native and planned acetabulum positions are exported with the associated spatial information. The files are then displayed on mixed reality head mounted device (HoloLens2, Microsoft) following intraoperative registration using an FDA-cleared mixed reality application designed primary for hip arthroplasty (HipInsight). PAO was performed on both sides of a bone model (Pacific Research). The osteotomies and acetabular reposition were performed in accordance with the displayed holograms. Post-op CT imaging was performed for analysis. Cutting plane-accuracy was evaluated using a best-fit plane and 2D angles (°) between the planned and achieved supra (SA)- and retroacetabular (RA) osteotomy and retroacetabular and ischial osteotomies (IO) were measured.To evaluate the accuracy of acetabular reorientation, we digitized the acetabular rim and calculated the acetabular opening plane. Absolute errors of planned and achieved operative inclination and anteversion (°) of the acetabular fragment, as well as 3D lateral-center-edge (LCE) angles were calculated.The mean absolute difference between the planned and performed osteotomy angles was 3 ± 3°.The mean absolute error between planned and achieved operative anteversion and inclination was 1 ± 0° and 0 ± 0° respectively. Mean absolute error between planned and achieved 3D LCE angle was 0.5 ± 0.7°.Mixed-reality guidance for the performance of pelvic osteotomies and acetabular fragment reorientation was feasible and highly accurate. This solution may improve the current standard of care by enabling reliable and precise reproduction of the desired acetabular realignment.

Intraoperative computerised tomography scan for percutaneous fixation of the pelvis: a retrospective case series

PurposeFractures and dislocations of the pelvic ring are complex injuries that when treating require meticulous attention to detail and often specialized technical skill. These injuries can be the result of high-energy trauma, particularly in younger patients, or low energy trauma more often found in the elderly. Regardless of mechanism, these injuries lie on a spectrum of severity and can be treated conservatively or surgically. Percutaneous fixation under fluoroscopic guidance is the preferred standard technique when treating these fractures. This technique can be challenging for a variety of reasons including patient characteristics, intra-operative image quality, fracture morphology, among others.MethodsThis retrospective study evaluated the use of intra-operative computed tomography (CT) using an O-arm imaging system for critical evaluation of fluoroscopic-guided screw placement in twenty-three patients. We retrospectively reviewed all cases of patients who were treated by three fellowship-trained orthopaedic traumatologists during a one-year span. Patients undergoing percutaneous pelvis fixation using both standard fluoroscopy and intraoperative CT with the Medtronic O-arm® (Minneapolis, MN) imaging system. Additionally, procedures performed included open reduction internal fixation (ORIF) of the pelvic ring, acetabulum, and associated extremity fractures.ResultsTwenty-three patients were included in this study. On average, the use of intraoperative CT added 24.4 min in operative time. Five patients (21.7%) required implant adjustment after O-arm spin. Fourteen patients underwent additional post-operative CT. No secondary revision surgeries were attempted after any post-operative CT.ConclusionsOur study suggests that intra-operative CT scan, compared to post-operative CT scan, can be utilized to prevent take-back surgery for misplaced implants and allow for adjustment in real-time.

Early Bone and Suture Reformations in Different Cranial Regions After Cranial Vault Remodeling for Sagittal Craniosynostosis.

Cranial vault remodeling (CVR) is a common procedure for correcting sagittal craniosynostosis. Some approaches leave significant craniectomy defects. The authors investigated the reosteogenesis in different cranial defect areas after CVR. A cross-sectional study was conducted in nonsyndromic sagittal craniosynostosis. Available early postoperative computed tomography (CT) scans were analyzed. The segmentation of three-dimensional reconstructed images was performed. Different cranial defect areas, including coronal, vertex, and occipital regions, were further investigated using an automated three-dimensional analysis software for reosteogenesis percentage. Forty-four CT scans were included. The average age at CVR was 8.8 months. The median time of postoperative CT scans was 6.1 weeks. The median bone reformation percentage of the entire cranial defect was 56.7%. Given the similar postoperative CT timing, the median bone reformation at the coronal, vertex, and occipital areas demonstrated 44.21%, 41.13%, and 77.75%, respectively (P < 0.001). In the simultaneously removed coronal and lambdoid sutures, there were 45% with coronal and lambdoid sutures reformation, followed by lambdoid suture reformation alone, no suture reformation and coronal reformation alone in 35%, 20%, and 0%, respectively (P = 0.013). There was no coronal reformation in the removed coronal suture group. However, 40% demonstrated lambdoid suture reformation after the isolated lambdoid suture removal. The occipital region has the highest reosteogenesis compared with the other cranial defects after CVR in nonsyndromic sagittal craniosynostosis. Within the removed previous patent sutures, the lambdoid suture reformation showed a higher rate than the coronal suture.

Which type of supra-syndesmal fractures Weber C or Equivalent Weber C have the best reduction of the distal tibio-fibular syndesmosis? A prospective CT-scan investigation on 60 ankles

IntroductionThe reduction of the distal tibiofibular syndesmosis (SyTFd) is a crucial factor in the functional prognosis following a suprasyndesmotic ankle fracture. Few studies have compared, using computed tomography (CT), the quality of SyTFd reduction in Weber C ankle fractures (WebC) and Equivalent Weber C (EqWebC) fractures, where there is a medial ligament injury instead of a bony malleolar lesion. This CT-based study aimed to answer the following questions: (1) Do Weber C fractures allow for better reduction of the distal tibiofibular syndesmosis compared to Equivalent Weber C fractures? (2) Are the functional outcomes one year postoperatively better for Weber C fractures compared to Equivalent Weber C fractures? HypothesisThe hypothesis was that WebC fractures would present better reduction of the SyTFd than EqWebC fractures due to the restoration of bone anatomy, considering the bony nature of the medial ligament involvement. Materials and methodsSince December 2021, all patients presenting with an ankle fracture were included in a database. Suprasyndesmotic fractures were extracted, and between December 2021 and February 2022, 60 patients underwent surgery for a suprasyndesmotic fracture (28 WebC – 32 EqWebC). All patients were operated on using the same technique and underwent a postoperative bilateral CT scan in axial slices with both ankles in a neutral position (foot at 90 ° to the leg). An analysis of 8 measurements was performed under the same conditions. Each fractured ankle was compared to the healthy contralateral ankle, and a delta was obtained for each measurement. The follow-up was standardized. At one year, an AOFAS Score and a Maryland Foot Score (MFS) were recorded. Statistical differences between the two groups were measured using the Student's t-test and Chi-square test. ResultsThere was a significant difference between the WebC and EqWebC groups for clinical scores at one year postoperatively: AOFAS: 92.0 ± 6.3 [78–100] vs. 80.1 ± 5.4 [62–100], p < 0.05; MFS: 90.9 ± 6.4 [78–100] vs. 81.6 ± 5.2 [64–100], p < 0.05. CT scan analysis of the SyTFd reduction found significantly better reduction in the WebC group. DiscussionWebC fractures showed better clinical scores associated with better SyTFd reduction on postoperative CT scans. The anatomical reduction related to the bone reduction criteria during surgery could explain our findings. Level of evidenceIII; Case-Control Comparative Study.

Computer-Assisted Hip Arthroscopic Surgery for Secondary Femoroacetabular Impingement After Rotational Acetabular Osteotomy Using Capsular Takedown Techniques

Secondary femoroacetabular impingement (FAI) is a severe complication observed after acetabular osteotomy; however, the diagnostic and treatment strategies of FAI have not been well established, especially with respect to arthroscopic techniques. We here describe hip arthroscopic osteochondroplasty for secondary FAI using computer-assisted techniques. The main features and tips of our technique are preoperative computed tomography (CT)-based surgical planning and the intraoperative capsule takedown method. Computer modeling produces a patient-specific 3-dimensional CT bone model. Subsequently, we identify the impingement point between the acetabulum and the femoral neck using dynamic simulation. The excess bony bumps are resected through computer surgical simulation, and pre- and postoperative 3-dimensional CT bone models are combined to identify the appropriate resection area. For the surgical technique, it is important to detach the capsule to visualize the acetabulum bony excess. Once the resection area has been sufficiently visualized, the bone resection is performed. Finally, the capsule is reattached to the excavated acetabulum, and the delaminated labrum is sewn up with the capsule in a round bale shape.