Preoperative Planning Stage Research Articles

Use of pre-operative 3D planning software for revision shoulder arthroplasty: clinical experience data from a survey in a real-world setting

BackgroundPreoperative 3D planning is routinely used in primary shoulder arthroplasty, while specific challenges in the revision setting make such approaches more cumbersome and less accessible. Recently, an established preoperative planning software (Blueprint; Stryker, Tornier SA, Montbonnot-Saint-Martin, France) was expanded to offer a capability for planning of revision and complex primary shoulder arthroplasty cases. The aim of this study was to survey experienced surgeons on their perception of the new software feature for preoperative 3D planning in the setting of revision shoulder arthroplasty. MethodsAn observational survey was conducted from January 2022 to October 2022 among orthopedic surgeons performing revision shoulder arthroplasty cases. The survey was part of the Early Product Surveillance program, with the primary goal of obtaining observational data from surgical experience in a real-world setting. A two-staged survey process was applied with separate questionnaires to seek voluntary feedback on the preoperative planning phase as well as on the intra-operative evaluation of the software planning features in revision shoulder arthroplasty. ResultsTwenty-five fellowship-trained orthopedic surgeons from the USA and Canada participated in the survey and reported their feedback on 34 revision shoulder arthroplasty cases that were preoperatively planned with use of Blueprint revision planning software. The surgeons were largely in favor of the revision software planning features and confirmed perceived benefits of its use in the preoperative planning stage of revision shoulder arthroplasty cases. Reported benefits in the preoperative planning phase included increased efficiency and improved ease of creating an appropriate surgical plan, as well as increased confidence to execute revision shoulder arthroplasty cases. Surgeons also noted improvements in translation of preoperative planning to intra-operative execution of revision cases, including more appropriate implant selection and improved accuracy of implant placement. ConclusionThe feedback from fellowship-trained shoulder arthroplasty surgeons on the use of the new software feature for preoperative 3D planning of revision shoulder arthroplasty is largely favorable. Further research should be conducted to investigate whether these surgeon-perceived benefits can lead to improved clinical outcomes for patients.

Multimodal MRI segmentation of key structures for microvascular decompression via knowledge-driven mutual distillation and topological constraints.

Microvascular decompression (MVD) is a widely used neurosurgical intervention for the treatment of cranial nerves compression. Segmentation of MVD-related structures, including the brainstem, nerves, arteries, and veins, is critical for preoperative planning and intraoperative decision-making. Automatically segmenting structures related to MVD is still challenging for current methods due to the limited information from a single modality and the complex topology of vessels and nerves. Considering that it is hard to distinguish MVD-related structures, especially for nerve and vessels with similar topology, we design a multimodal segmentation network with a shared encoder-dual decoder structure and propose a clinical knowledge-driven distillation scheme, allowing reliable knowledge transferred from each decoder to the other. Besides, we introduce a class-wise contrastive module to learn the discriminative representations by maximizing the distance among classes across modalities. Then, a projected topological loss based on persistent homology is proposed to constrain topological continuity. We evaluate the performance of our method on in-house dataset consisting of 100 paired HR-T2WI and 3D TOF-MRA volumes. Experiments indicate that our model outperforms the SOTA in DSC by 1.9% for artery, 3.3% for vein and 0.5% for nerve. Visualization results show our method attains improved continuity and less breakage, which is also consistent with intraoperative images. Our method can comprehensively extract the distinct features from multimodal data to segment the MVD-related key structures and preserve the topological continuity, allowing surgeons precisely perceiving the patient-specific target anatomy and substantially reducing the workload of surgeons in the preoperative planning stage. Our resources will be publicly available at https://github.com/JaronTu/Multimodal_MVD_Seg .

Strong Correlation Between Standing Long-Leg Radiographs and CT Scans in Measuring Coronal Knee Alignment.

The objective of this study was to evaluate the correlation in measurements of the lower-limb coronal alignment between long-leg radiographs (LLRs) and computed tomography (CT) scanograms that were made during preoperative planning for robotic-arm-assisted knee arthroplasty. On the basis of published evidence demonstrating a good correlation between these imaging modalities in measuring the lower-limb mechanical axis, we hypothesized that there would be no significant differences between the 2 in the present study. This multicenter cohort study across 3 tertiary centers included 300 patients undergoing primary robotic-arm-assisted total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) for whom LLRs and CT scanograms were available preoperatively. The study involved measuring the medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), hip-knee-ankle angle (HKA), joint line obliquity (JLO), joint-line convergence angle (JLCA), and arithmetic HKA (aHKA). The aHKA represents a method for estimating constitutional alignment using angles that are unaffected by joint-space narrowing. Strong correlations (p < 0.001) between the imaging modalities were found for the HKA (correlation coefficient, 0.912), aHKA (0.883), MPTA (0.820), LDFA (0.871), and JLO (0.778). A weaker correlation was observed for the JLCA in valgus knees as compared with varus knees (Spearman coefficients, 0.412 and 0.518, respectively). Regression models demonstrated that the degree of agreement was associated with the preoperative intra-articular deformity and the positioning of the lower limb during the CT scan (i.e., the lower-limb rotational angle). An initial JLCA within ±5° was associated with higher agreement. We observed a strong correlation between LLRs and CT scanograms that were made during the preoperative planning stage of robotic-arm-assisted knee arthroplasty, implying that CT scanograms can reliably be utilized to estimate the coronal alignment of the knee, potentially replacing the need for LLRs. Nevertheless, to attain a higher degree of agreement, it is crucial to ensure appropriate radiographic positioning of the lower limb. Additionally, surgeons must remain vigilant regarding potential discrepancies in cases involving substantial deformities. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Optimizing Aesthetic Outcomes in Autologous Breast Reconstruction: 20 Pearls for Practice.

Autologous breast reconstruction with a deep inferior epigastric artery perforator (DIEP) flap is an excellent option for many patients proceeding with mastectomy for surgical management of their breast cancer. As microsurgical techniques and results improve and ensure consistent flap survival, optimizing aesthetic outcomes may become a primary focus. This article outlines 20 tips that can improve aesthetic results in DIEP flap breast reconstruction, based on our senior author's 8-year career in microsurgical breast reconstruction, with an emphasis on enhanced cosmesis. We highlight tips on preoperative planning, intraoperative, and revision stages of the reconstruction and provide a schematic for integrating the tips into a reader's microsurgical breast reconstruction practice.

Facial Feminization Surgery: Anatomical Differences, Preoperative Planning, Techniques, and Ethical Considerations.

Facial Feminization Surgery (FFS) is a transformative surgical approach aimed at aligning the facial features of transgender women with their gender identity. Through a systematic analysis, this paper explores the clinical differences between male and female facial skeletons along with the craniofacial techniques employed in FFS for each region. The preoperative planning stage is highlighted, emphasizing the importance of virtual planning and AI morphing as valuable tools to be used to achieve surgical precision. Consideration is given to special circumstances, such as procedure sequencing for older patients and silicone removal. Clinical outcomes, through patient-reported outcome measures and AI-based gender-typing assessments, showcase the efficacy of FFS in achieving proper gender recognition and alleviating gender dysphoria. This comprehensive review not only offers valuable insights into the current state of knowledge regarding FFS but also emphasizes the potential of artificial intelligence in outcome evaluation and surgical planning to further advance patient care and satisfaction with FFS.

Customized Denonvilliers' Fascia Excision: An Advanced Total Mesorectal Excision Technique for Anteriorly Located Rectal Cancer.

The role of Denonvilliers' fascia in achieving a negative circumferential resection margin during anterior total mesorectal excision has been controversial. Opinions on whether to dissect in the anterior or posterior surgical plane varies among researchers. We performed total mesorectal excision with selective en bloc resection of Denonvilliers' fascia based on preoperative MRI staging, preoperative clinical tumor stage, and tumor level in selected patients with anterior rectal tumors adherent to Denonvilliers' fascia. Between March and August 2021, 5 patients who underwent robotic (n = 4) and laparoscopic (n = 1) total mesorectal excision for anteriorly located low rectal adenocarcinomas after neoadjuvant chemoradiotherapy were enrolled in this study. Transabdominal total mesorectal excision dissection is performed by changing to a plane anterior to Denonvilliers' fascia, with partial or total excision tailored to the tumor level and depth of invasion as a further step in circumferential resection margin clearing. Customized excision of Denonvilliers' fascia was performed by dissecting through the extramesorectal plane. This anterior plane permits resection of Denonvilliers' fascia, exposing the prostate and seminal vesicles. Two tumors were located at the seminal vesicle level and 3 were found at the prostate level. The mean distance from the anal verge to the distal margin of the tumor was 4.8 ± 0.9 cm. Denonvilliers' fascia was preserved in 1 patient and partially excised in 4. Customized Denonvilliers' fascia excision was performed in 3 robotic ultralow anterior resections with coloanal anastomosis, 1 laparoscopic ultralow anterior resection with coloanal anastomosis, and 1 robot-assisted abdominoperineal resection. The circumferential resection margins in all patients were negative. Anterior dissection in front of Denonvilliers' fascia can be selectively performed during total mesorectal excision based on preoperative planning, tumor location, and clinical tumor stage. Preoperative MRI and magnified operative views in minimally invasive platforms provide access to more precise surgical planes for clear circumferential resection, achieving optimal functional outcomes and oncological safety.

Vascularized osseous flaps for head and neck reconstruction: Comparative analysis focused on complications and salvage options

ObjectivesThis study aimed to compare the clinical outcomes of fibular (FFF group) and scapular (SFF group) osseous free flaps for reconstructing head and neck defects for primary surgery and salvage options. MethodsWe analyzed 156 cases of osseous free flaps in 138 patients from a retrospective review of a single institutional database between January 1996 and January 2020 (FFF, 114 cases in 99 patients; SFF, 42 cases in 39 patients). Clinical profiles such as age, sex, primary tumor site, and defect type were investigated in the two groups. In addition, the incidences and types of perioperative complications, flap compromise, and salvage management were compared between the two groups. ResultsFFF was used mostly for oromandibular defects, whereas SFF was preferred for maxillary defect reconstruction. The length of hospital stay was longer in the FFF group than in the SFF group. The flap compromise rate was not significantly different between the two groups; however, donor-site complications were not observed in the SFF group as compared to 7.9% in the FFF group. A regional or free (musculo) cutaneous flap was used as a salvage procedure in partial flap compromise. Contralateral SFF was available to replace a completely compromised SFF, whereas it was not feasible in a completely compromised FFF. Cox proportional hazards analysis showed no significant prognostic factors for flap-related complications. ConclusionThe two osseous free flaps showed differences in defect type, flap donor complications, and options for compromised flap salvage. These findings must be considered carefully in the preoperative planning stage to guarantee early recovery and timely administration of postoperative adjuvant treatment if necessary.

Laparoscopic resection of localized tumors of horseshoe kidney parenchyma using 3D printing: clinical observation

The use of 3D-computer technologies (3D-modeling, 3D-printing) in the surgical treatment of patients with kidney abnormalities contributes to a better understanding of anatomy at the preoperative planning stage and improves intraoperative navigation. We present a clinical observation using 3D-printing during performing organ-preserving laparoscopic surgery in a patient with localized formations of the horseshoe kidney parenchyma.

THE LIFETIME MORPHOMETRY OF CARDIOESOPHAGEAL TRANSITION IN PATIENTS WITH HIATAL HERNIA

With the development of X-ray technology and the advent of computed tomography, it became possible not only to accurately diagnose hiatal hernia, but also to conduct morphometry of all its constituent anatomical structures in different projections to use the data obtained at the stage of preoperative planning for its surgical treatment. Currently, due to the improvement in the quality of diagnostics, there is an increase in the detection of patients with this pathology, along with this, the question of choosing the most rational method of treatment is acute. The aim of the study was to study the computed tomographic anatomy of the structures of the cardioesophageal junction in patients with hiatal hernia. A retrospective study of a series of computed tomograms in 53 patients with hiatal hernia, performed on a 64-slice Canon Aquilion Prime tomograph, was carried out. An assessment was made of the diameter of the distal esophagus, the size of the hernia orifice, and the deviation of the axis of the esophagus at the level of the hernial orifice relative to the diaphragm in two planes. As a result of the analysis, it was found that in 79% of cases the esophagus was located on the right and behind the hernial sac, in 13% - behind and in the middle, in 8% - on the left and behind. It was revealed that the diameter of the unchanged part of the esophagus above the hernial sac was 20.9±3.71 mm (min – 15.7 mm, max – 30.2 mm). The dimensions of the hernial orifice varied within 31.21±5.23 mm in the frontal plane (min - 24.7 mm, max - 42 mm) and 32.66±4.36 mm in the sagittal plane (min - 26.2 mm, max - 39.1 mm). The deviation of the axis of the esophagus in the frontal plane was 63.53°±16.74 (min - 19.6°, max - 92.3°). The deviation of the axis of the esophagus in the sagittal plane was 74.12°±21.31 (min - 36.3°, max - 118.1°). Thus, due to the variability in the structure and location of the anatomical structures of the cardioesophageal zone in patients with hiatal hernia, it is necessary to take into account all of the above indicators, including the presence or absence of large branches of the greater omentum in the hernial sac, body type, gender, age of patients, which serves an integral part of preoperative planning of surgical treatment, optimization and reduction of complications, as well as determining the safest method of its surgery.

Correlation between Scoliosis Flexibility Degree on Preoperative Imaging with Postoperative Curve Correction and Mechanical Complications

(1) Background: In the preoperative planning stage of scoliosis surgery, it is routine to use radiographs obtained with and without traction to observe the curve flexibility in order to estimate curve correction, but its association with mechanical complications is not completely understood. (2) Methods: Retrospective cohort study of all patients undergoing infantile, congenital, neuromuscular or idiopathic adolescent scoliosis correction surgery at a single institution between 2015 and 2019, with a minimum follow-up of 24 months. Associations between qualitative variables were tested with the chi-square test. The association between qualitative and quantitative variables were tested with the Mann–Whitney test, and correlations between quantitative variables was tested with Spearman’s correlation. (3) Results: A total of 330 patients, 88 males and 242 females, with a mean age of 16.98 years at surgery, were included. The mean value of preoperative main curves, its flexibility and postoperative value were 54.44 degrees, 21.73 degrees and 18.08 degrees, respectively. (4) Conclusions: Preoperative spinal X-ray examination with traction or bending films is a reasonable option for assessing scoliotic curve flexibility, and patients with neuromuscular scoliosis who are not ambulatory can be informed of the increased risks of late mechanical complications.

Combining simple interactivity and machine learning: a separable deep learning approach to subthalamic nucleus localization and segmentation in MRI for deep brain stimulation surgical planning.

Purpose: Deep brain stimulation (DBS) is an interventional treatment for some neurological and neurodegenerative diseases. For example, in Parkinson's disease, DBS electrodes are positioned at particular locations within the basal ganglia to alleviate the patient's motor symptoms. These interventions depend greatly on a preoperative planning stage in which potential targets and electrode trajectories are identified in a preoperative MRI. Due to the small size and low contrast of targets such as the subthalamic nucleus (STN), their segmentation is a difficult task. Machine learning provides a potential avenue for development, but it has difficulty in segmenting such small structures in volumetric images due to additional problems such as segmentation class imbalance. Approach: We present a two-stage separable learning workflow for STN segmentation consisting of a localization step that detects the STN and crops the image to a small region and a segmentation step that delineates the structure within that region. The goal of this decoupling is to improve accuracy and efficiency and to provide an intermediate representation that can be easily corrected by a clinical user. This correction capability was then studied through a human-computer interaction experiment with seven novice participants and one expert neurosurgeon. Results: Our two-step segmentation significantly outperforms the comparative registration-based method currently used in clinic and approaches the fundamental limit on variability due to the image resolution. In addition, the human-computer interaction experiment shows that the additional interaction mechanism allowed by separating STN segmentation into two steps significantly improves the users' ability to correct errors and further improves performance. Conclusions: Our method shows that separable learning not only is feasible for fully automatic STN segmentation but also leads to improved interactivity that can ease its translation into clinical use.

Thoracolumbar and Lumbar Posterior Vertebral Resection for the Treatment of Rigid Congenital Spinal Deformities in Pediatric Patients: A Long-Term Follow-up Study

ObjectiveWe sought to determine whether a posterior vertebral resection on congenital deformities of thoracolumbar and lumbar vertebrae leads to more complications and provides less correction.MethodsTwenty-three patients underwent a posterior vertebral resection for a rigid congenital spinal deformity, which included scoliosis (13 patients), kyphoscoliosis (6 patients), and pure kyphosis (4 patients). The surgeries involved removing 1 to 2 vertebrae using multiaxial pedicle screws in all but 2 of the patients. All surgeries were performed under intraoperative spinal cord monitoring. Thoracic curve, lumbar lordosis, focal kyphosis, shift, and sagittal vertical axis were collected at baseline and during the last follow-up (taking place after at least 3 years) and were then statistically analyzed.ResultsThe major curve correction was about 55% in cases of scoliosis, with focal kyphosis improving from 54.3 ± 19.1 degrees to 21.3 ± 15 degrees. Two patients experienced intraoperative neuromonitoring changes, with data returning to baseline without any surgical intervention. Sensory or motor palsy after the surgery was not reported in patients.Despite improving sagittal or coronal deformities, 8 patients experienced excessive sagittal decompensation during follow-up, 1 of whom underwent revision surgery. Sagittal decompensation was by far the most common complication. Larger kyphoscoliosis or focal kyphosis angles were preoperative risk factors for postoperative sagittal imbalance (P value < 0.05).ConclusionsUsing a lumbar or thoracolumbar posterior vertebral resection enables surgeons to correct rigid curves in the pediatric population without major risk to nerve roots. The primary complications would be sagittal decompensation and the likelihood of undercorrection, which requires mindful addressing during the preoperative planning stages.

Generalization of the relationships between sagittal balance geometric parameters

Sagittal balance of the spine characterizes its physiological alignment by muscular forces in the most effective way. Optimal spinal-pelvic relationships form a biomechanically efficient and optimal sagittal profile of the spine, which reduces energy consumption for an equilibrium state maintaining and also decrease the risk of degenerative damage to the intervertebral discs. Sagittal balance is described using the main angular parameters: pelvic incidence, lumbar lordosis, pelvic tilt and sacral slope. To form optimal spinal-pelvic relationships during surgical treatment surgeons measure the actual balance parameters of the patient and use empirical formulas to calculate their theoretical values at preoperative planning stage. To calculate the optimal parameters of the sagittal balance of a particular patient, various scientific groups have developed a number of empirical dependencies. However, there is no consensus in the scientific community on what specific formulas to use when planning treatment. This paper attempts to generalize the data available in the scientific literature on the parameters of the sagittal balance and to develop new generalizing regression dependencies that allow one to link the parameters of the sagittal balance. For this purpose, the source data used for constructing such dependencies were collected from the literature. The results of the sagittal balance measurement of Saratov State Medical University patients were also used in this study. We selected the initial numerical data linking the main parameters of the sagittal balance from the literature. The data was digitized and processed using statistics methods. Regression dependencies were obtained that allow calculating lumbar lordosis pelvic tilt, and sacral slope through the pelvic incidence of a particular patient. Generalizing dependences make it possible to systematize the clinical experience accumulated in the literature and were used in the development of the world's first system for preoperative planning of surgical treatment of the consequences and diseases of the spine-pelvic complex with biomechanical support of the doctor's decision.

A clinico-statistical study of factors associated with intraoperative bleeding in orthognathic surgery

BackgroundExcessive bleeding is a major intraoperative risk associated with orthognathic surgery. This study aimed to investigate the factors involved in massive bleeding during orthognathic surgeries so that safe surgeries can be performed. Patients (n=213) diagnosed with jaw deformities and treated with bimaxillary orthognathic surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) in the Department of Oral and Maxillofacial Surgery at the Suidobashi Hospital, Tokyo Dental College between January 2014 and December 2016 were included. Using the patients’ medical and operative records, the number of cases according to sex, age at the time of surgery, body mass index (BMI), circulating blood volume, diagnosis of maxillary deformity, direction of maxillary movement, operative duration, incidence of bad split, injury of nasal mucosa, and blood type were analyzed.ResultsThe results revealed that BMI, circulating blood volume, nasal mucosal injury, and operative time were associated with the risk of intraoperative massive bleeding in orthognathic surgeries. Chi-square tests and binomial logistic regression analyses showed significant differences in BMI, circulating blood volume, direction of maxillary movement, operative duration, and injury to the nasal mucosa. Operative duration emerged as the most important risk factor. Furthermore, a >4-mm upward migration of the posterior nasal spine predicted the risk of massive bleeding in orthognathic surgery.ConclusionsThe upward movement of the maxilla should be recognized during the preoperative planning stage as a risk factor for intraoperative bleeding, and avoiding damage to the nasal mucosa should be considered a requirement for surgeons to prevent massive bleeding during surgery.

Evaluation and Verification of Fast Computational Simulations of Stent-Graft Deployment in Endovascular Aneurysmal Repair.

Fenestrated Endovascular Aortic Repair, also known as FEVAR, is a minimally invasive procedure that allows surgeons to repair the aorta while still preserving blood flow to kidneys and other critical organs. Given the high complexity of FEVAR, there is a pressing need to develop numerical tools that can assist practitioners at the preoperative planning stage and during the intervention. The aim of the present study is to introduce and to assess an assistance solution named Fast Method for Virtual Stent-graft Deployment for computer assisted FEVAR. This solution, which relies on virtual reality, is based on a single intraoperative X-ray image. It is a hybrid method that includes the use of intraoperative images and a simplified mechanical model based on corotational beam elements. The method was verified on a phantom and validated on three clinical cases, including a case with fenestrations. More specifically, we quantified the errors induced by the different simplifications of the mechanical model, related to fabric simulation and aortic wall mechanical properties. Overall, all errors for both stent and fenestration positioning were less than 5 mm, making this method compatible with clinical expectations. More specifically, the errors related to fenestration positioning were less than 3 mm. Although requiring further validation with a higher number of test cases, our method could achieve an accuracy compatible with clinical specifications within limited calculation time, which is promising for future implementation in a clinical context.

Patient-centered oncosurgical planning with cancer models in subspecialty education

BackgroundA fundamental aspect of oncosurgical planning in organ resections is the identification of feeder vessel details to preserve healthy organ tissue while fully resecting the tumors. The purpose of this study was to determine whether three-dimensional (3D) cancer case models of computed tomography (CT) images will assist resident-level trainees in making appropriate operative plans for organ resection surgery. MethodsThis study was based on the perception of surgery residents who were presented with 5 different oncosurgical scenarios. A five-station carousel including cases of liver mass, stomach mass, annular pancreas, pelvic mass and mediastinal mass was formed for the study. The residents were required to compare their perception level of the cases with their CT images, and 3D models in terms of identifying the invasion of the mass, making differential diagnosis and preoperative planning stage. ResultsAll residents have given higher scores for models. 3D models provided better understanding of oncopathological anatomy and improved surgical planning. In all scenarios, 70–80% of the residents preferred the model for preoperative planning. For surgical choice, compared to the CT, the model provided a statistically significant difference in terms of visual assessment, such as tumor location, distal or proximal organotomy (p:0.009). In the evaluation of presacral mass, the perception of model was significantly better than the CT in terms of bone-foramen relationship of chondrosarcoma, its origin, geometric shape, localization, invasion, and surgical preference (p:0.004). The model statistically significantly provided help to evaluate and prepare the case together with the colleagues performing surgery (p:0.007). Commenting on the open-ended question, they stated that the tumor-vessel relationship was clearly demonstrated in the 3D model, which has been very useful. ConclusionsWith the help of 3D printing technology in this study, it is possible to implement and evaluate a well-structured real patient scenario setup in cancer surgery training. It can be used to improve the understanding of pathoanatomical changes of multidisciplinary oncologic cases. Namely, it is used in guiding the surgical strategy and determining whether patient-specific 3D models change pre-operative planning decisions made by surgeons in complex cancer mass surgical procedures.

Robotic Surgical Assistant Rehearsal: Combining 3-Dimensional-Printing Technology With Preoperative Stereotactic Planning for Placement of Stereoencephalography Electrodes.

The use of frameless stereotactic robotic technology has rapidly expanded since the Food and Drug Administration's approval of the Robotic Surgical Assistant (ROSA) in 2012. Although the use of the ROSA robot has greatly augmented stereotactic placement of intracerebral stereoelectroencephalography (sEEG) for the purposes of epileptogenic focus identification, the preoperative planning stages remain limited to computer software. To describe the use of a 3-dimensionally (3D)-printed patient model in the preoperative planning of ROSA-assisted depth electrode placement for epilepsy monitoring in a pediatric patient. An anatomically accurate 3D model was created and registered in a preoperative rehearsal session using the ROSA platform. After standard software-based electrode trajectory planning, sEEG electrodes were sequentially placed in the 3D model. Utilization of the 3D-printed model enabled workflow optimization and increased staff familiarity with the logistics of the robotic technology as it relates to depth electrode placement. The rehearsal maneuvers enabled optimization of patient head positioning as well as identification of physical conflicts between 2 electrodes. This permitted revision of trajectory planning in anticipation of the actual case, thereby improving patient safety and decreasing operative time. Use of a 3D-printed patient model enhanced presurgical positioning and trajectory planning in the placement of stereotactic sEEG electrodes for epilepsy monitoring in a pediatric patient. The ROSA rehearsal decreased operative time and increased efficiency of electrode placement.

A simplified preoperative risk assessment tool as a predictor of complications in the surgical management of forearm fractures

PurposeFrailty is a well-known predictor of adverse postoperative outcomes and is often considered in the preoperative planning stage of surgery. In recent years, the modified frailty index (mFI), a novel metric used to quantify frailty, has become increasingly used in the orthopedic literature as a risk assessment tool. In this study, we analyze the utility of the mFI in predicting unplanned repeat operations and morbidity in the surgical treatment forearm fractures. MethodsWe used the American College of Surgeons National Surgical Quality Improvement Program 2006–2014 dataset to identify patients undergoing open fixation of forearm fractures. The mFI was calculated based on 5 possible comorbid conditions. Demographic and predictor variables were analyzed for associations with each outcome. In order to assess frailty in both the general and elderly population, two analyses were completed: one for the entire population and one for a population of age 65 or older. The primary outcome of interest was unplanned repeat operation. Secondary outcomes included discharge destination and major post-operative complications. Chi square and logistic regression analyses were used to identify associations. ResultsA total of 4641 patients were included in our final analysis. There was a higher prevalence of females and patients between the ages of 61 and 80 compared to other age groups. An mFI score ≥2 was a positively associated with unplanned repeat operation in the general population. An mFI score ≥2 was also positively associated with a discharge destination other than home and major post-operative complications. In the elderly population, mFI ≥2 was similarly associated with a discharge destination other than the patient’s home. ConclusionsPatients undergoing open treatment of forearm fractures were at an increased likelihood of having an unplanned repeat operation and having major complications as frailty score increased, demonstrating that the mFI may be clinically applicable risk assessment tool for these patients.

Three-Dimensional Printed Anatomical Models Help in Correcting Foot Alignment in Hallux Valgus Deformities.

Hallux valgus (HV) is the most common pathologic entity affecting the great toe. The goal of corrective surgery is to restore foot mechanics and provide pain relief. The purpose of the study was to create individual angle using life-size foot models with three-dimensional (3D) printing technology to design a section on HV osteotomy. Ten female patients with a diagnosis of HV were included. Radiologic [HV angle and intermetatarsal (IM) angle] and clinical [American Orthopaedic Foot and Ankle Score (AOFAS)] assessment was done pre- and postoperatively. All the operations were planned together with 3D life-size models generated from computed tomography (CT) scans. Benefits of using the 3D life-size models were noted. The 3D model's perception was evaluated. The mean AOFAS score, mean HV, and IM angles had improved significantly (P < 0.05). The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical planning. At the first tarsometatarsal joint, the HV models showed significantly greater dorsiflexion, inversion, and adduction of the first metatarsal relative to the medial cuneiform. At the first metatarsophalangeal joint, the HV models showed significantly greater eversion and abduction of the first proximal phalanx relative to the first metatarsal. It provided satisfactory results about operation time and blood loss. 3D model's perception was statistically significant (P < 0.05). 3D models help to transfer complex anatomical information to clinicians, which provide guidance in the preoperative planning stage, for intraoperative navigation. It helps to create a patient-specific angle section on osteotomy to correct IM angle better and improve postoperative foot function. The 3D personalized model allowed for a better perception of information when compared to the corresponding 3D reconstructed image provided.

Variant Anatomy of the Renal Arteries: a Computed Tomography Angiography Study

The article discusses variant anatomy of the renal arteries, potentials of three-dimensional modeling and use of these data in clinical practice. Despite a large number of studies based on both morphological and clinical approaches there is no general consensus regarding options for dividing the renal artery, the number of its branches, their topolocalization. This is due to the fact that most of the research studies are based on cadaveric material, fixed and unfixed. It is difficult to apply these data to explain medical conditions and pathologies of particular patients. Computed tomography allows performing in vivo investigation of various morphometric parameters of the renal arteries, and these findings can subsequently be used in disease diagnostics and treatment.The aim of the study was to identify patterns of topography, linear dimensions and variant anatomy of the human renal arteries based on computed tomography angiography (CTA) with three-dimensional modeling, and to apply CTA findings in clinical practice.Material and methods. The study included CTA images of the abdomen of 130 patients, and their threedimensional models. A hardware-software complex "Luch-S" and software complex "Avtoplan" (Russian project) were used to perform morphometric analysis. The diameter of the renal artery mouth, the level of origin of the renal artery mouths, as well as the angles between the renal arteries and the abdominal aorta were analyzed morphometrically and statistically.Results. The authors have developed recommendations how to use three-dimensional modeling of vascular- organ complexes in patients at the stage of preoperative planning and intraoperative navigation in clinical practice. Generated dataset of personalized morphometric data can be applied to teach basic operation techniques involving possible damage to abnormal vessels, as well as training specific surgical procedures involving the kidney and its vessels in a simulation-based surgical clinic.