Current and emerging 3D visualization technologies in radiology.

As the field of three-dimensional (3D) visualization rapidly advances, how healthcare professionals perceive and interact with real and virtual objects becomes increasingly complex. Lack of clear vocabulary to navigate the changing landscape of 3D visualization hinders clinical and scientific advancement, particularly within the field of radiology. In this article, we provide foundational definitions and illustrative examples for 3D visualization in clinical care, with a focus on the pediatric patient population. We also describe how understanding 3D visualization tools enables better alignment of hardware and software products with intended use-cases, thereby maximizing impact for patients, families, and healthcare professionals.

Experimental guide wire placement for total shoulder arthroplasty in glenoid models: higher precision for patient-specific aiming guides compared to standard technique without learning curve.

BACKGROUND: Patient-specific aiming devices (PSAD) may improve precision and accuracy of glenoid component positioning in total shoulder arthroplasty, especially in degenerative glenoids. The aim of this study was to compare precision and accuracy of guide wire positioning into different glenoid models using a PSAD versus a standard guide. METHODS: Three experienced shoulder surgeons inserted 2.5 mm K-wires into polyurethane cast glenoid models of type Walch A, B and C (in total 180 models). Every surgeon placed guide wires into 10 glenoids of each type with a standard guide by DePuy Synthes in group (I) and with a PSAD in group (II). Deviation from planned version, inclination and entry point was measured, as well as investigation of a possible learning curve. RESULTS: Maximal deviation in version in B- and C-glenoids in (I) was 20.3° versus 4.8° in (II) (p < 0.001) and in inclination was 20.0° in (I) versus 3.7° in (II) (p < 0.001). For B-glenoid, more than 50% of the guide wires in (I) had a version deviation between 11.9° and 20.3° compared to ≤ 2.2° in (II) (p < 0.001). 50% of B- and C-glenoids in (I) showed a median inclination deviation of 4.6° (0.0°-20.0°; p < 0.001) versus 1.8° (0.0°-4.0°; p < 0.001) in (II). Deviation from the entry point was always less than 5.0 mm when using PSAD compared to a maximum of 7.7 mm with the standard guide and was most pronounced in type C (p < 0.001). CONCLUSION: PSAD enhance precision and accuracy of guide wire placement particularly for deformed B and C type glenoids compared to a standard guide in vitro. There was no learning curve for PSAD. However, findings of this study cannot be directly translated to the clinical reality and require further corroboration.

The Dugdale planning method for high tibial osteotomies underestimates the correction angle compared to the Miniaci method.

PURPOSE: The purpose of this study was to compare the planning methods of Dugdale and Miniaci for high tibial osteotomies (HTO) and to assess how their use could influence on the degree of correction and thus the postoperative weight bearing line (WBL). METHODS: Pre- and postoperative standing hip-knee-ankle (HKA) radiographs were obtained from 70 patients that underwent HTO. The correction angles were determined using Dugdale's and Miniaci's methods, and for the latter, both for an opening wedge as well for a closing wedge osteotomy. In a subset of 50 patients, the calculations were performed twice by two observers to calculate inter- and intra-rater reliability. Regression analysis and Bland-Altman plots were used to compare the methods. Whereas the Dugdale method had been used in the planning of the real operations, a regression model was used to predict how the obtained correction would have been if the Miniaci method had been used instead. RESULTS: Intra- and inter-rater reliability was excellent for the correction angle for both Dugdale's (0.992 and 0.991) and Miniaci's methods (0.988 and 0.987). When planning for an opening wedge osteotomy (OW) and a closing wedge osteotomy (CW), using the Miniaci method and comparing the correction angle with the angle obtained by the Dugdale method, the Miniaci OW and CW angles were larger by a factor of 1.07 (95% CI 1.06-1.08) and 1.10 (95% CI 1.09-1.11). Postoperatively, a mean undercorrection of 2.9° (SD = 2.3) was found. Predicting the correction with use of the calculated Miniaci angles resulted in an undercorrection of 2.5°, indicating that use of the Dugdale method accounted for 14% of the undercorrection. CONCLUSION: It is more likely to underestimate the correction angle when using the Dugdale method compared to the Miniaci method. This could lead to poorer correction accuracy. As the inter-rater reliability is excellent for both methods, choosing to use the Dugdale method on basis of simplicity is not justified. LEVEL OF EVIDENCE: III, Diagnostic study.

Impact of three-dimensional printed planning in Paprosky III acetabular defects: a case-control and cost-comparison analysis.

PURPOSE: The main challenges in revision total hip arthroplasty (rTHA) are the treatment of the bone loss and the pre-operative planning. 3D-printed models may enhance pre-operative planning. The aim of the study is to compare the intra- and peri-operative results and costs for Paprosky type 3 rTHAs planned with 3D-printed models to ones accomplished with the conventional imaging techniques (X-rays and CT scan). METHODS: Seventy-two patients with Paprosky type 3 defect underwent rTHA between 2014 and 2021. Fifty-two patients were treated with standard planning and 20 were planned on 3D-printed models. Surgical time, intra-operative blood loss, number of transfused blood units, number of post-operative days of hospitalization, and use of acetabular rings were compared between the two groups. A costs comparison was also performed. RESULTS: The 3D-printed group showed reduced operative time (101.8 min (SD 27.7) vs. 146.1 min (SD 49.5), p < 0.001) and total days of hospitalization (9.3 days (SD 3.01) vs. 12.3 days (SD 6.01), p = 0.009). The cost of the procedures was significantly lower than the control group, with an adjusted difference of 4183 euros (p = 0.004). No significant differences were found for the number of total transfused blood units and blood loss and the number of acetabular rings. CONCLUSION: The use of 3D-printed models led to a meaningful cost saving. The 3D-printed pre-operative planning for complex rTHAs seems to be effective in reducing operating time, hospital stay and overall costs.

Internal Hemipelvectomy for primary bone sarcomas using intraoperative patient specific instruments- the next step in limb salvage concept.

BACKGROUND: During pelvic Sarcoma resections, Surgeons often struggle to obtain negative margins while minimizing collateral damage and maintaining limb function. These complications are usually due to the complex anatomy of the pelvis. Here we present an accurate 3D surgical approach, including pre-operative printing of models and intraoperative patient-specific instruments (PSIs) for optimizing pelvic sarcoma resections. METHODS: This single-center retrospective study (N = 11) presents surgical, functional, and oncological outcomes of patients (average age 14.6 +/- 7.6 years, 4 males) who underwent pelvic sarcoma resections using a 3D surgical approach between 2016 and 2021. All patients were followed up for at least 24 months (mean = 38.9 +/- 30.1 months). RESULTS: Our results show promising surgical, oncological, and functional outcomes. Using a 3D approach, 90.9% had negative margins, and 63.6% did not require reconstruction surgery. The average estimated blood loss was 895.45 ± 540.12 cc, and the average surgery time was 3:38 ± 0.05 hours. Our results revealed no long-term complications. Three patients suffered from short-term complications of superficial wound infections. At 24 month follow up 72.7% of patients displayed no evidence of disease. The average Musculoskeletal Tumor Society (MSTS) score at 12 months was 22.81. CONCLUSION: 3D technology enables improved accuracy in tumor resections, allowing for less invasive procedures and tailored reconstruction surgeries, potentially leading to better outcomes in function and morbidity. We believe that this approach will enhance treatments and ease prognosis for patients diagnosed with pelvic sarcoma and will become the standard of care in the future.

Augmented reality and three-dimensional plate library-assisted posterior minimally invasive surgery for scapula fracture.

PURPOSE: Treating scapular fractures is still a challenging task for surgeons. We aimed to evaluate the feasibility, accuracy, and effectiveness of augmented reality (AR) and three-dimensional (3D) plate library-assisted posterior minimally invasive surgery, named AR-scapular system for scapula fracture. We speculated that using AR-scapular system would improve efficiency and quality for scapular fracture surgery. METHODS: We retrospectively reviewed the records of 21 patients with scapular fractures treated by posterior minimally invasive surgery with reconstruction plates: nine patients were treated with conventional fixation in group I; whereas 12 patients were treated with pre-operative virtual simulation and intra-operative navigation-assisted fixation using AR-scapular system. We compared operative time, blood loss, complication, and Hardegger function between two groups. Statistical analyses evaluated significant differences between the groups for each of these variables. RESULTS: In group II, the pre-operative virtual simulation time was 44.42 ± 15.54 min. The time required for pre-operative contouring of the plates was 16.08 ± 5.09 minutes. The patients in group II had significantly shorter operation time and less blood loss (- 28.75 min and - 81.94 ml, respectively; P < 0.05) than patients in the conventional surgery group. The average numbers of plates used were 1.56 ± 0.53 in group I and 1.25 ± 0.45 in group II. The difference was not statistically significant (P > 0.05). The follow-up function outcome results were similar between groups (P > 0.05). There were no intra-operative or post-operative complications for all patients. CONCLUSION: Augmented reality and 3D plate library-assisted posterior minimally invasive surgery is an effective and reliable method for treating scapular fractures which can provide precise pre-operative planning and intraoperative navigation. This time-saving approach can give a more customized treatment plan, allowing for a safer reduction surgery. What is more, the portable projector is cheap and easy to use.

High intra- and inter-observer reliability of planning implant size in MRI-based patient-specific instrumentation for total knee arthroplasty.

PURPOSE: Patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) uses individually designed disposable guides to determine intraoperative bone cuts. The manufacturer provides the surgeon with proposed planning which can be modified and should be approved by the surgeon before the guides are produced. This study aims to assess the intra- and inter-observer reliability among preoperative planning by orthopaedic surgeons using PSI. The authors hypothesize a high intra- and inter-observer reliability in planning TKA using PSI. METHODS: Four orthopaedic surgeons modified and approved 40 preoperative MRI-based PSI plannings three times. The surgeons were blinded to their own and each other's results. Intra- and inter-observer reliability was obtained for planned implant size, resection, and position of the implant. RESULTS: Intra-observer reliability Intraclass Correlation Coefficients (ICC) were excellent for femoral and tibial implant size with a range of 0.948-0.995 and 0.919-0.988, respectively. Inter-observer reliability for femoral and tibial implant size showed an ICC range of 0.953-0.982 and 0.839-0.951, respectively. Next to implant size, intra- and inter-observer reliability demonstrated good to an excellent agreement (ICC > 0.75) for 7 out of 12 remaining parameters and 6 out of 12 remaining parameters, respectively. CONCLUSION: Preoperative planning of TKA implant size using MRI-based PSI showed excellent intra- and inter-observer reliability. Further research on the comparison of predicted implant size preoperatively to intraoperative results is needed.

Characterizing Patient Questions Before and After Rhinoplasty on Social Media: A Big Data Approach.

BACKGROUND: As an aesthetic surgery, a successful rhinoplasty is often assessed by patient satisfaction, subject to a diverse array of qualitative factors including patient expectations and happiness with care provided. While substantial effort has been dedicated to understanding patients' post-operative concerns, addressing patients' pre-operative questions has been comparatively less studied. This study analysed pre- and post-operative questions about rhinoplasty on social media to gain insights into patients' concerns and develop targeted educational material. METHODS: The most viewed rhinoplasty questions on Realself.com, a social media platform for discussions about cosmetic surgeries, were collected and analysed. Questions were then stratified into pre- and post-operative and further assigned categories based on common topics found in the data. Using a machine learning approach, the most common pre- and post-operative questions were determined. RESULTS: 2014 rhinoplasty questions were collected in total, with 957 pre-operative and 1057 post-operative. The most commonly asked pre-operative questions were about appearance (n = 441, 46.1%), function (n = 102, 10.7%), and cost (n = 94, 9.8%). The most commonly asked post-operative questions were about appearance (n = 502, 47.5%), behaviour allowed/disallowed (n = 283, 26.8%), and symptoms after surgery (n = 235, 22.2%). An educational handout with the 10 most common pre- and post-operative questions was developed using machine learning analysis, with the majority of questions about appearance. CONCLUSIONS: Patients primarily expressed concern about appearance when asking questions about rhinoplasty on social media, along with other aspects of their pre- and post-operative course. The educational handout developed by this study can be applied to address commonly asked patient questions during pre-operative education. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Advanced hepatic vasculobiliary imaging segmentation and 3D reconstruction as an aid in the surgical management of high biliary stenosis.

BACKGROUND: Three-dimensional (3D) models are increasingly used to help surgeons, guiding them through the complex hepatic vasculobiliary anatomy. The biliary tract is a relatively untapped territory with only a few case reports described in medical literature. Our aim is to present an innovative 3D reconstruction methodology for biliary imaging and surgical planning, applied to a case of iatrogenic biliary stricture, with fusion of segmented CT and MRI images. CASE PRESENTATION: A selected case of Bismuth type III iatrogenic biliary stenosis for 3D planning. CT and MR studies were acquired with dedicated protocols for segmentation. Two radiologists performed segmentation and 3D model post-processing, fusing both imaging techniques to faithfully render the anatomical structures. Measurements of anatomical landmarks were taken in both the CT/MRI and the 3D model to assure its accuracy and differences in measurement were calculated. The 3D model replicates anatomical structures and pathology with high accuracy, with only 2.2% variation between STL, CT and MRI measurements. The model was discussed with the surgical team and used in the surgical planning, improving confidence in this delicate procedure, due to the detailed prior knowledge of the patient's anatomy. CONCLUSION: Three-dimensional reconstructions are a rapidly growing area of research with a significant impact in the personalized and precision medicine. The construction of 3D models that combine vascular and biliary anatomy, using different imaging techniques, respectively CT and MRI, will predictably contribute to a more rigorous planning of complex liver surgeries.

Electrical cortical stimulation for treatment of intractable epilepsy originating from eloquent cortex: surgical accuracy and clinical efficacy.

BACKGROUND: Electrical cortical stimulation is shown effective in treating patients with drug-resistant epilepsy. We demonstrated how detailed procedures of pre- and intra-operative planning of cortical stimulation implantation may influence the results of seizure reduction rate. METHODS: To confirm the precision of subdural grids covering the epileptogenic foci in the eloquent regions, pre- and intra-operative video-electroencephalography (VEEG) were performed in patients with drug-resistant epilepsy during a 4-day 24-h monitoring. The localization of the grid was determined via 3D reconstruction imaging of subdural electrodes co-registered onto the patient's cortex. A final quadripolar lead in cyclic stimulation mode was then placed and secured on the target cortex area. Post-operative 3D CT ensured the accurate location of stimulation lead without any misplacement. Bipolar cyclic stimulation and post-implantation VEEG were performed for 7 days. Patients were discharged and followed up regularly for parameters adjustment and recording of seizure outcomes. RESULTS: Eight patients received chronic cortical stimulation implantations between February 2003 and December 2017. The mean age of these patients was 21.1 years old and the average post-operative follow-up was 77.3 months. Comparisons of their seizure frequency at baseline and during the postoperative period revealed a mean reduction in seizures of 60.4% at the first year and 65.6% at the second year. CONCLUSIONS: Pre-surgical planning enhanced the accuracy of electrode placement and led to a favorable seizure reduction rate. Our report confirms that electrical cortical stimulation with detailed implantation procedures is safe and effective for patients with drug-resistant epilepsy originating from eloquent cortex.

Pre-operative planning in THA. Part III: do implant size prediction and offset restoration influence functional outcomes after THA?

INTRODUCTION: Few studies evaluated clinical benefits of pre-operative templating in total hip arthroplasty (THA). We investigated whether mismatch between planned and real implant sizes and medio-lateral offsets compromises THA outcomes. MATERIALS AND METHODS: We reviewed records of 184 primary THAs with pre-operative CT scans used for templating. Acetabular offset (AO), femoral offset (FO) and global offset (GO) were measured on pre-operative CT scans, during acetate templating, and post-operative antero-posterior radiographs. Multivariable analyses were performed to determine if Forgotten Joint Score (FJS) and Oxford Hip Score (OHS) at > 2 years were associated with differences between post-operative and planned parameters. RESULTS: The FJS and OHS were not influenced by mismatch of component sizes nor of FO and GO. The FJS was better when the post-operative AO was greater than planned (p = 0.050). The FJS differed among arthritic types (p = 0.015). Multivariable analyses confirmed that older patients had better OHS (beta - 0.16; p = 0.033) and FJS (beta 0.74; p = 0.002), medialized hips had worse FJS (beta - 20.1; p = 0.041) and hips with greater AO than planned had better FJS (beta 1.71; p = 0.024) CONCLUSIONS: Implanting a component of different size than planned did not compromise THA outcomes, but medialized hips had worse scores, and conservative acetabular reaming improved scores.

Pre-operative templating in THA. Part II: a CT-based strategy to correct architectural hip deformities.

INTRODUCTION: Pre-operative templating for total hip arthroplasty (THA) remains inaccurate due to improper magnification and alignment. We aimed to describe an improved templating strategy using computed tomography (CT) to predict component sizes and offsets with greater accuracy. MATERIALS AND METHODS: We analysed 184 CT images acquired for pre-operative templating of primary THA. We aimed to restore native (pre-arthritic) femoral offset and limb length, by raising the head center to the level of the templated cup center cranio-caudally, but maintaining the pathologic (pre-operative) head center medio-laterally (except in medialized hips). Acetabular offset (AO) and femoral offset (FO) were measured on pre-operative CT scans, during acetate templating, and on post-operative true antero-posterior radiographs. RESULTS: The post-operative offsets were within ± 5 mm from templated estimates in 174 hips (91%) for AO, in 116 hips (61%) for FO, in 111 hips (58%) for GO, and in 134 hips (70%) for neck cut level. The post-operative hip architecture reproduced the templated hip architecture within ±5 mm in 77 hips (40%). The agreement between planned and post-operative parameters was moderate for stem size (0.57), cup size (0.62), AO (0.50), but fair for FO (0.45). The AO decreased in most arthritic types, notably in lateralized hips (6.6 mm), but remained unchanged in medialized hips. The FO increased in most arthritic types (1.8-3.1 mm) but remained unchanged in medialized and lateralized hips. CONCLUSIONS: We described a strategy for pre-operative templating in THA. Despite the accuracy of CT, the authors found significant variations between planned and post-operative reconstructions, which suggest that pre-operative templating should only be used as an approximate guide.

3D modeling: a future of cardiovascular medicine 1.

Cardiovascular disease resulting from atypical cardiac structures continues to be a leading health concern despite advancements in diagnostic imaging and surgical techniques. However, the ability to visualize spatial relationships using current technologies remains a challenge. Therefore, 3D modeling has gained significant interest to understand complex and atypical cardiovascular disorders. Moreover, 3D modeling can be personalized and patient-specific. 3D models have been demonstrated to aid surgical planning and simulation, enhance communication among surgeons and patients, optimize medical device design, and can be used as a potential teaching tool in medical schools. In this review, we discuss the key components needed to generate cardiac 3D models. We highlight prevalent structural conditions that have utilized 3D modeling in pre-operative planning. Furthermore, we discuss the current limitations of routine use of 3D models in the clinic as well as future directions for utilization of this technology in the cardiovascular field.

Significant differences between manufacturer and surgeon in the accuracy of final component size prediction with CT-based patient-specific instrumentation for total knee arthroplasty.

PURPOSE: Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) may improve component sizing. Little has been reported about accuracy of the default plan created by the manufacturer, especially for CT-based PSI. The goal of this study was to evaluate the reliability of this plan and the impact of the surgeon's changes on the final accuracy of the guide sizes. METHODS: Forty-five patients eligible for primary TKA were prospectively enrolled. The planned implant sizes were prospectively recorded from the initial manufacturer's proposal and from the final plan adjusted in light of the surgeon's evaluation; these two sizes where then compared to the actually implanted sizes. Fisher's exact test was used to test differences for categorical variables. Agreement between pre-operative plans and final implant was evaluated with the Bland-Altman method. RESULTS: The manufacturer's proposal differed from the final implant in 9 (20.0%) femoral and 23 (51.1%) tibial components, while the surgeon's plan in 6 (13.3%, femoral) and 12 (26.7%, tibial). Modifications in the pre-operative plan were carried out for five (11.1%) femoral and 23 (51.1%) tibial components (p = 0.03). Appropriate modification occurred in 22 (88.0%) and 19 (76.0%) cases of femoral and tibial changes. The agreement between the manufacturer's and the surgeon's pre-operative plans was poor, especially with regard to tibial components. CONCLUSION: The surgeon's accuracy in predicting the final component size was significantly different from that of the manufacturer and changes in the initial manufacturer's plan were necessary to get an accurate pre-operative plan of the implant sizes. CLINICAL RELEVANCE: Careful evaluation of the initial manufacturer's plan by an experienced knee surgeon is mandatory when planning TKA with CT-based PSI. LEVEL OF EVIDENCE: II.

Using pre-operative MRI to predict intraoperative hamstring graft size for anterior cruciate ligament reconstruction.

PURPOSE: Large variation in tendon size between individuals makes hamstring graft diameter for anterior cruciate ligament (ACL) reconstruction unpredictable. Inadequate graft diameter may necessitate an alternative source of tissue requiring pre-operative planning. The purpose of this study was to determine whether magnetic resonance image (MRI) measurements and clinical anthropometric data are predictive of hamstring tendon graft diameter. METHODS: Data from 109 patients having ACL reconstruction with semitendinosus-gracilis (STGT) autograft were retrospectively evaluated. Cross-sectional area (CSA) of the gracilis tendon (GT) and semitendinosus tendon (ST) were determined from pre-operative MRI scans. Variables included pre-operative height, weight, body mass index (BMI), age and gender; and intra-operative graft diameter. RESULTS: Correlations between anthropometric variables, hamstring tendons CSA and intra-operative graft diameter were calculated. Multiple stepwise regression was performed to assess the predictive value of these variables to graft diameter. Sensitivity and specificity were calculated to evaluate the utility of MRI CSA measurements in accurately identifying inadequate graft diameter (<8 mm). All anthropometric variables were positively correlated with intraoperative graft diameter (p < 0.01). Semitendinosus-gracilis tendon CSA (p < 0.001) and STGT CSA and weight (p < 0.001) were significantly predictive models of graft diameter. Sensitivity and specificity were 79 and 74 %, respectively. CONCLUSION: The strongest indicators of a four-stranded STGT graft for primary ACL reconstruction were STGT CSA on MRI plus weight. Measurement of graft diameter can be performed pre-operatively via MRI to identify tendons that may be of inadequate size for ACL reconstruction. This can assist with surgical planning to determine the most appropriate graft choice. LEVEL OF EVIDENCE: III.

Comparison between cylindrical axis-reference and articular surface-reference femoral bone cut for total knee arthroplasty.

PURPOSE: Reproducing a functional flexion-extension axis (FEA) of the femur is key to achieving successful collateral ligament balance and joint line in total knee arthroplasty (TKA). This study compared the feasibility of cylindrical axis (CA)-reference bone cut and articular surface-reference bone cuts in reproducing the FEA for Japanese osteoarthritis patients. METHODS: The study enrolled 122 knees from 86 patients who underwent primary TKA due to grade III or IV osteoarthritis. Data from pre-operative CT were reconstructed into three-dimensional (3D) models using 3D-planning software. Cylindrical radii of the condyles were measured, and femoral bone cut angles relative to anatomical landmarks were determined in the coronal and axial reference planes based on CA-reference and articular surface-reference methods. RESULTS: Mean cylindrical radii for medial and lateral femoral condyles were 17.4 ± 1.6 and 17.3 ± 1.4 mm, respectively. Of the 122 knees, 46 exhibited >1 mm of difference between condyles. Fifty-three and 22 knees exhibited >2° of angular difference between CA-reference and articular surface-reference bone cuts in the coronal and axial planes. Mean angle of the CA and surgical epicondylar axis in 3D space was 4.6 ± 2.1°. As practical parameters for TKA, the angle between CA and IM rod was significantly larger than that between the distal articular surface line and IM rod in the coronal plane (p < 0.0001), indicating that CA-reference involves a smaller valgus bone cut of the distal femur than articular surface reference. CONCLUSIONS: CA-reference bone cut of the femur is preferable to articular surface-reference bone cut for reproducing FEA in Japanese OA patients, in whom more than one-third of knees exhibited asymmetry of radii between medial and lateral condyles. In clinical practice, the CA-reference bone cut represents a good technical option for kinematically aligned TKA in the Japanese population.

Correlation of Prediction and Actual Outcome of Three-Dimensional Simulation in Breast Augmentation Using a Cloud-Based Program.

BACKGROUND: Breast augmentation is among the most frequently performed cosmetic plastic surgeries. Providing patients with "realistic" 3D simulations of breast augmentation outcomes is becoming increasingly common. Until recently, such programs were costly and required significant equipment, training, and office space. New simple user-friendly cloud-based programs have been developed, but to date there remains a paucity of objective evidence comparing these 3D simulations with the post-operative outcomes. OBJECTIVES: To determine the aesthetic similarity between pre-operative 3D simulation generated by Crisalix and real post-operative outcomes. METHODS: A retrospective review of 20 patients receiving bilateral breast augmentation was conducted comparing 6-month post-operative outcomes with 3D simulation using Crisalix software. Similarities between post-operative and simulated images were measured by three attending plastic surgeons and ten plastic surgery residents using a series of parameters. RESULTS: Assessment reveals similarity between the 3D simulation and 6-month post-operative images for overall appearance, breast height, breast width, breast volume, breast projection, and nipple correction. Crisalix software generated more representative simulations for symmetric breasts than for tuberous or ptotic breasts. Comparison of overall aesthetic outcome to simulation showed that the post-operative outcome was more appealing for the symmetric and tuberous breasts and less appealing for the ptotic breasts. CONCLUSIONS: Our data suggest that Crisalix offers a good overall 3D simulated image of post-operative breast augmentation outcomes. Improvements to the simulation of the post-operative outcomes for ptotic and tuberous breasts would result in greater predictive capabilities of Crisalix. Collectively, Crisalix offers good predictive simulations for symmetric breasts. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Radiographic templating of total hip arthroplasty for femoral neck fractures.

PURPOSE: The purpose of this study was to evaluate the use of pre-operative digital templating to minimize complications including limb length discrepancy (LLD), intraoperative fractures and early dislocations in patients with intracapsular femoral neck fractures. METHODS: We retrospectively compared 23 patients undergoing total hip arthroplasty (THA) for intracapsular femoral fractures with pre-operative digital templating and 48 patients without templating. RESULTS: The mean post-operative LLD was significantly lower in patients who had pre-operative templating than in the control group (6.7 vs. 11.5 mm, p = 0.023). Only three patients (13 %) with templating had LLD greater than 1.5 cm, compared to the 15 patients (31 %) without templating (p = 0.17). In eight cases the final femoral stem size matched the templated size, while 19 patients were within two size increments. Complications included one dislocation and one intra-operative fracture in the control group. CONCLUSION: The present study demonstrated that careful pre-operative planning may reduce LLD in patients undergoing THA due to intracapsular hip fractures.

[Application of 3D soft print models of the kidney for treatment of patients with localized cancer of the kidney (a pilot study)].

AIM: To evaluate the possibility of using 3D-printing in the management of patients with localized kidney cancer. MATERIALS AND METHODS: The study comprised five patients with localized kidney cancer who were treated at the Urology Clinic of the I.M. Sechenov First Moscow State Medical University from January 2016 to April 2017. Along with the standard examination, the patients underwent multispiral computed tomography (MSCT) to produce patient-specific 3D-printed models of the kidney tumors using 3D modeling and 3D printing. To evaluate the effectiveness of using 3D-printed models, two-stage preoperative planning was conducted, and five surgeons were surveyed using a four-question multiple choice questionnaire. At the first stage, the planning of operations was carried out based on MSCT findings. At the second stage, the surgeons were given patient-specific soft 3D models of the kidney with a tumor for preoperative training. After preoperative training, patients underwent laparoscopic resection of the kidney with a tumor. RESULTS: According to the survey results, each of the participating surgeons at least once changed surgical plan based on data obtained with 3D printed models of the kidney with the tumor. The implementation of preoperative training using 3D printed models of the kidney turned out to be effective. All patients underwent laparoscopic surgery performed by a single surgeon with extensive experience in this type of surgery. The mean operative time was 187 minutes. All operations were performed with main renal artery occlusion. The men warm ischemia time was 19.5 minutes and the mean blood loss was 170 ml. There were no conversions to open surgery and organ-removing operations. There were no postoperative complications or deaths. All surgical margins were negative. Morphological examination showed that four patients had renal cell carcinoma one patient had the oncocytoma. CONCLUSION: The study demonstrated the promise of using 3D printing for preoperative planning and surgical performance due to a high-precision three-dimensional soft patient-specific model of the localized kidney.

Application of three-dimensional computerised tomography reconstruction and image processing technology in individual operation design of developmental dysplasia of the hip patients.

PURPOSE: Acetabular coverage deficiency displays individual difference among patients with developmental dysplasia of the hip (DDH). Therefore, the correct direction and degree of the acetabular fragment is patient-specific during Bernese periacetabular osteotomy (PAO). This paper introduces a feasible method using 3D computed tomography (CT) and computer image processing technology for customised surgical planning. METHODS: CT data of 96 hips in 60 DDH patients (male 15, female 45; average age/range 30 ± 8/14-49 years) and 53 normal hips (male 13, female 37; average age/range 52 ± 13/16-69 years) were reconstructed using commercially available software Mimics and Imageware. Geometric parameters of each hip were measured in relation to the anterior pelvic plane after correcting for pelvic tilt and rotation. Deficiency types and degrees of acetabular dysplasia in patients with DDH were determined by comparison with normal hips, and improvement in femoral-head coverage was analysed again after virtual PAO. A customised surgery programme for each DDH patient was designed and provided the reference for the actual operation. RESULTS: We produced a 3D pelvic model using image processing software, doing precise measurement and with close approximation to the actual PAO. Lateral centre-edge angle (LCEA), anterior centre-edge angle (ACEA), acetabular anteversion angle (AAVA), anterior acetabular sector angle (AASA) and posterior acetabular sector angle (PASA) of normal hips in the control group were 35.128 ± 6.337, 57.052 ± 6.853, 19.215 ± 5.504, 61.537 ± 7.291 and 99.434 ± 8.372°, respectively. Angles of hips with DDH before surgery were 11.46 ± 11.19, 35.79 ± 13.75, 22.77 ± 6.13, 43.58 ± 9.15 and 88.46 ± 8.24, which were corrected to 33.81 ± 2.36, 55.38 ± 2.09, 20.16 ± 2.18, 58.29 ± 7.60, and 4.71 ± 7.75°, respectively, after surgery. After virtual Bernese PAO, LCEA, ACEA, AAVA, AASA and PASA were corrected significantly (p < 0.01). There was no statistically significant differences between LCEA, ACEA and AAVA after virtual Bernese PAO and normal hips (p = 0.06, p = 0.23, p = 0.06°, respectively). AASA improved significantly (p = 0.002) post-operatively at the cost of reducing posterior coverage represented by PASA, which is significantly smaller than in normal and pre-operative hips of DDH patients (p < 0.01). CONCLUSIONS: The geometric feature of the pelvis for patients with DDH can be assessed comprehensively by using 3D-CT reconstruction and image processing technology. Based on this method, surgeons can design individualised treatment scheme and improve the effect of PAO.