3D Group Research Articles

3D-printed antibiotic-loaded bone cement spacers as adjunctive therapy for hip periprosthetic infection after arthroplasty: A clinical assessment

ObjectiveTo explore the effect of 3D-printing technology in assisting the treatment of periprosthetic infection after total hip arthroplasty (THA) by using personalized antibiotic-loaded bone cement (ALBC) spacers. MethodsThe data of 40 patients with postoperative infection after THA were retrospectively analyzed. The patients were divided into 3D printing group (age 47-78 years) and conventional group (age 57-78 years), with 20 cases in each group. In the stage I surgery, the 3D printing group used 3D printed silicone molds to create ALBC spacers, while the conventional group used traditional manual methods. After the infection was controlled, both groups underwent conventional hip revision surgery in the stage II surgery. All patients were evaluated by Harris hip score (HHS) (primary outcome) for hip function. ResultsAll 40 patients had follow-up data, with 3 months after the first stage and 12 months after the second stage. HHS: The intergroup difference was 11.25 points (97.5% confidence interval (CI), 7.92 to 14.58; P <0.01) at 3 months after the first stage, and 9.15 points (97.5% CI, 4.82 to 13.48; P <0.01) at 12 months after the second stage, and the overall difference between the two groups was 9.55 points (97.5% CI, 5.83 to 13.27; P <0.01), which was statistically significant (P<0.05). ConclusionDuring the follow-up period, the hip functional of the 3D printing group were superior to those of the conventional group in the treatment of infections after THA.

The effect of various surface treatments on the repair bond strength of denture bases produced by digital and conventional methods.

There is limited information on the repairability of prostheses produced with digital technology. This study aims to evaluate various surface treatments on flexural bond strength of repaired dentured base resins produced by digital and conventional methods. A total of 360 samples were prepared from one heat-polymerized, one CAD/CAM milled and one 3D printed denture base materials. All of the test samples were subjected to thermocycling (5-55°C, 5000 cycles) before and after repair with auto-polymerizing acrylic resin. The test samples were divided into five subgroups according to the surface treatment: grinding with silicon carbide (SC), sandblasting with Al2O3 (SB), Er:YAG laser (L), plasma (P) and negative control (NC) group (no treatment). In addition, the positive control (PC) group consisted of intact samples for the flexural strength test. Surface roughness measurements were performed with a profilometer. After repairing the test samples, a universal test device determined the flexural strength values. Both the surface topography and the fractured surfaces of samples were examined by SEM analysis. The elemental composition of the tested samples was analyzed by EDS. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis of data. SB and L surface treatments statistically significantly increased the surface roughness values of all three materials compared to NC subgroups (p < 0.001). The flexural strength values of the PC groups in all three test materials were significantly higher than those of the other groups (p < 0.001). The repair flexural strength values were statistically different between the SC-SB, L-SB, and NC-SB subgroups for the CAD/CAM groups, and the L-SC and L-NC subgroups for the 3D groups (p < 0.001). The surface treatments applied to the CAD/CAM and heat-polymerized groups did not result in a statistically significant difference in the repair flexural strength values compared to the NC groups (p > 0.05). Laser surface treatment has been the most powerful repair method for 3D printing technique. Surface treatments led to similar repair flexural strengths to untreated groups for CAD/CAM milled and heat-polymerized test samples.

Enzymological Studies of the Functional State of the Kidney Parenchyma in Children of the Younger Age Group with Congenital Megaureter

The objective: to determine the activity levels of total N-acetyl-β-D-glucosaminidase (NAG), its heat-stable isoenzyme NAG B and β-galactosidase (β-Gal) as enzymological criteria of the functional state of the kidney parenchyma, in particular its tubular part, in the urine of younger children age group with congenital megaureter (MU) depending on the degree of suppression of the urodynamics of the upper urinary tract (UUT). Materials and methods. Before reconstructive treatment 103 children aged 0.5 to 15 years with various clinical variants of congenital MU were examined. According to the degree of suppression of urodynamics of the UUT, the patients were divided into three groups: 1st group – 32 patients with I degree (initial degree), 2nd group – 41 children with II degree (medium one), 3rd group – 30 patients with III degree (expressed one). The control group included 25 practically healthy children. Patients were divided into two subgroups by age. Subgroup “a” included 29 patients aged from 0.5 to 3 years (average age – 1.4±0.5 years), of which 9 patients were examined in the 1st group, 13 persons – in the 2nd group, in 3d group – 7 patients. Subgroup “b” included 74 children aged 4 to 15 years (average age – 8.3±1.5 years). Enzymological activity of the morning portion of urine in patients was determined by the colorimetric method. Statistical processing of data was performed after analyzing the conformity of their distribution to normality. Results. It was established that the total activity of NAG and the activity of NAG B in the urine of all patients with congenital MU with the I degree of suppression of urodynamics of the UUT, regardless of age, probably exceeded the average data of similar indicators in the control group (p&lt;0.05–0.001). In children with congenital MU with II degree suppression of urodynamics of the UUT, regardless of age, a similar trend of changes in the activity levels of all the studied enzymes was determined, compared to patients of the 1st group (р&lt;0.02–0.001). The total activity of NAG, the activity of NAG B and β-Gal in the urine of patients with III degree of suppression of urodynamics of the UUT probably exceeded similar indicators compared to patients of the 2nd group regardless of the age (p&lt;0.001). The results of the study showed that in patients with the I degree of suppression of urodynamics of the UUT between age groups there was no statistical probability of changes in the activity levels of the studied enzymes. In children under 3 years of age with III degree of inhibition of urodynamics of the UUT the levels of enzyme activity probably exceeded similar indicators in the group of patients of 3 years old and over (р&lt;0.05–0.001). Enzyme activity levels of NAG and NAG B in the urine of patients under 3 years old with II degree of suppression of urodynamics of the UUT also statistically significantly exceeded the similar indicators of sick children over 3 years old (p&lt;0.01). Conclusions. The intensity of the increase in the urinary activity of NAG, its thermostable isoenzyme NAG B and β-Gal in patients under 3 years old compared to the group of patients over the age of 3 years growths with an increase in the degree of suppression of the urodynamics of the UUT, which should be taken into account during treatment.

CLINICAL RESULTS OF CERVIX CANCER USING VARIOUS TECHNOLOGIES IN RADIATION THERAPY

Background: clinical results of patients with cervical cancer (CC) who treated with different methodological approaches of radiotherapy (RT) in the transforming from conventional to conformal RT and brachytherapy (BT).&#x0D; Purpose: to evaluate long-term results of treatment, locoregional and distant control.&#x0D; Methods: 137 patients with CC IIb - IIIb in 2013-2016 were analysed: 70 (51%) - conventional gamma therapy and brachytherapy (BT) with two-dimensional planning (2D) 60Сo alone or in combination with cisplatin 40 mg/m2 two groups of n=35. The total dose (TD) for point A 75.08 0.57 Gy, point B 57.9 0.43 Gy. In 67 (49%) with conform radiotherapy following BT with three-dimensional planning (3D) 192Ir alone or in combination with cisplatin 40 mg/m2 - two groups n = 35 and 32, respectively. TD CTV-HR D90 95.0 Gy 0.67 EQD2.&#x0D; Results: 3 and 5-year overall survival with 3D RT versus 2D RT was 84.6 4.5% and 63.1 6.0%; 84.6 4.5% versus 56.1 6.0%, respectively (p = 0.030). It was revealed that modern technologies are important in improving overall survival with image-guided RT: 88.2 6.6% of patients are alive for 3 years versus 59.0 8.4%, respectively (p=0.027). The use of chemoradiotherapy (CRT) showed an advantage of 3-year event-free survival in groups with 2D RT - 67.9 8.4% versus 55.2 8.6% (p = 0.042) in 3D RT - no statistically significant differences. Locoregional control was higher in the 3D RT groups at 3 years follow-up: 97.0 2.9% versus 82.9 5.3%, p = 0.050. CRT allows to reduce the number of local failures in the pelvis in the follow-up period up to 6 months, regardless of the RT technologies. The number of relapses and metastases in pelvis is lower in 3D RT - 3.0 2.1% versus 2D - 15.7 4.4% (p = 0.05). The frequency of metastases did not show statistically significant differences: 2D RT - 5.7 2.8% versus 3D RT - 9.0 3.5% (p 0.05).&#x0D; Conclusion: the study proves the improvement of local control in the treatment of cervical cancer in cases of conformal RT and 3D BT.

Comparison between conventional approach and three-dimensional mapping system in the catheter ablation of accessory pathway associated with coronary sinus diverticulum: A single-center experience.

Posteroseptal accessory pathways (APs) associated with coronary sinus (CS) diverticulum present a rare and challenge for ablation. This study aimed to compare the safety and efficacy of conventional approach and three-dimensional (3D) mapping system in the catheter ablation. This was a retrospective study of all patients (from January 2013 to July 2022) who underwent catheter ablation of posteroseptal AP associated with CS diverticula in our center. Patients who underwent catheter ablation using the traditional fluoroscopy method were included in the conventional method group (n = 13). Patients who underwent catheter ablation using the 3D mapping method were included in the 3D mapping group (n = 11). Clinical characteristics, ablation procedure, and outcomes were recorded and analyzed between the two groups. Out of 669 patients with posteroseptal APs, 24 of them (3.6%) were associated with CS diverticula. All patients in both groups successfully completed the electrophysiological study. In the conventional method group, two patients experienced complications (one patient with pericardial effusion and the other patient with femoral arterial hematoma), and two patients had recurrence. However, no patients suffered from complications or recurrence during follow-up. The procedure time and fluoroscopy time in the conventional method group were significantly longer than those in the 3D mapping method group. The utilization of 3D mapping led to reduced fluoroscopy time, shorter procedure duration, enhanced acute success rates, and decreased incidence of complications.

Comparing Three-dimensional and Two-dimensional Preoperative Planning for Lumbar Transpedicular Screw Placement: A Retrospective Study.

Transpedicular screw (TPS) misplacement is still a nightmare for spine surgeons. Preoperative planning is one of the methods that a surgeon could use to minimize this complication. This study aims to compare the efficacy of three-dimensional (3D) and two-dimensional (2D) preoperative planning in posterior lumbar TPSs placement performed using the freehand technique. Patients who underwent posterior TPSs placement for degenerative lumbar spondylolisthesis or spinal stenosis using the freehand technique between November 2021 and October 2022 were evaluated retrospectively. In total, 33 and 30 patients who met the inclusion criteria were consecutively operated on with preoperative 2D and 3D planning, respectively. The patients were divided into the 2D preoperative planning group (2DG) and 3D preoperative planning group (3DG) and the two groups were compared. Sixty-three patients were operated during the study period. There was no significant difference between the groups regarding blood transfusion, operation time, and radiation exposure. Although the accuracy of TPSs positioning was 94.2 and 96.5% in the 2DG and 3DG, respectively, the difference between the groups was not statistically significant. The upper facet joint violation rate was 12.8% (n = 20) in the 2DG versus 3.5% (n = 5) in the 3DG (p = 0.006). All L4 TPSs were inserted with their standard entry points without any modification (p < 0.0001; relative/risk ratio = 0.64). The modification rate was higher in L1, L2, and L5 TPSs (p < 0.0001; χ 2 = 24.7). For patients with degenerative lumbar diseases, 3D preoperative planning in posterior lumbar instrumentation surgeries performed with the freehand technique decreased the upper facet joint violation rate.

Three-dimensional versus two-dimensional laparoscopy for cholecystectomy in a canine cadaveric study.

To compare the effect of three-dimensional (3D) and two-dimensional (2D) laparoscopy on surgical time and intraoperative complications during cholecystectomies in canine cadavers. Experimental prospective study. Twelve canine cadavers. The laparoscopic cholecystectomies were performed in canine cadavers with four cannulas and with either 2D or 3D cameras by a single surgeon. The following surgical times were recorded: time from insertion of laparoscopic instruments to first endoclip placement, time from first endoclip placement to second endoclip placement, time from second endoclip placement to complete gall bladder dissection, and total surgical time. The cystic duct length distal to the first endoclip, intraoperative complications, and the amount of liver attached to the gall bladder were also recorded. Time from the insertion of the instruments to the application of the first endoclip was shorter for the 3D group than for the 2D group (p = .016). Other surgical times were not different between groups. There was no difference in the cystic duct length distal to the first endoclip, intraoperative complications, or the amount of liver attachment. Three-dimensional laparoscopy shortened the time from insertion of the laparoscopic instruments to placement of the first endoclip. However, total surgical time was not affected by the type of camera in laparoscopic cholecystectomy. Three-dimensional laparoscopy may be beneficial when performing procedures requiring enhanced spatial orientation. However, this technique did not shorten the total surgical time in this cadaveric study. Further studies in a clinical setting are necessary for the optimization of the future use of 3D laparoscopy.

Three-dimensional glass scaffolds improve the In Vitro maturation of porcine cumulus-oocyte complexes and subsequent embryonic development after parthenogenetic activation

In vitro maturation (IVM) methods for porcine oocytes are still deficient in achieving full developmental capacity, as the currently available oocyte in vitro culture systems still have limitations. In vitro embryo production must also improve the porcine oocyte IVM system to acquire oocytes with good developmental potential. Herein, we tested a three-dimensional (3D) glass scaffold culture system for porcine oocyte maturation. After 42 h, we matured porcine cumulus-oocyte complexes (COCs) on either two-dimensional glass dishes (2D-B), two-dimensional microdrops (2D-W), or 3D glass scaffolds. The 3D glass scaffolds were tested for porcine oocyte maturation and embryonic development. Among these culture methods, the extended morphology of the 3D group maintained a 3D structure better than the 2D-B and 2D-W groups, which had flat COCs that grew close to the bottom of the culture vessel. The COCs of the 3D group had a higher cumulus expansion index and higher first polar body extrusion rate, cleavage rate, and blastocyst rate of parthenogenetic embryos than the 2D-B group. In the 3D group, the cumulus-expansion-related gene HAS2 and anti-apoptotic gene Bcl-2 were significantly upregulated (p < 0.05), while the pro-apoptotic gene Caspase3 was significantly downregulated (p < 0.05). The blastocysts of the 3D group had a higher relative expression of Bcl-2, Oct4, and Nanog than the other two groups (p < 0.05). The 3D group also had a more uniform distribution of mitochondrial membrane potential and mitochondria (p < 0.05), and its cytoplasmic active oxygen species content was much lower than that in the 2D-B group (p < 0.05). These results show that 3D glass scaffolds dramatically increased porcine oocyte maturation and embryonic development after parthenogenetic activation, providing a suitable culture model for porcine oocytes.

Real-time telementoring with 3D drawing annotation in robotic surgery.

In telementoring, differences in teaching methods affect local surgeons' comprehension. Because the object to be operated on is a three-dimensional (3D) structure, voice or 2D annotation may not be sufficient to convey the instructor's intention. In this study, we examined the usefulness of telementoring using 3D drawing annotations in robotic surgery. Kyushu University and Beppu Hospital are located 140km apart, and the study was conducted using a Saroa™ surgical robot by RIVERFIELD Inc. using a commercial guarantee network on optical fiber. Twenty medical students performed vertical mattress suturing using a swine intestinal tract under surgical guidance at the Center for Advanced Medical Innovation Kyushu University. Surgical guidance was provided by Beppu Hospital using voice, 2D, and 3D drawing annotations. All robot operations were performed using 3D images, and only the annotations were independently switched between voice and 2D and 3D images. The operation time, needle movement, and performance were also evaluated. The 3D annotation group tended to have a shorter working time than the control group (25.6 ± 63.2 vs. -36.7 ± 65.4min, P = 0.06). The 3D annotation group had fewer retries than the control group (1.3 ± 1.7 vs. -1.1 ± 0.7, P = 0.006), and there was a tendency for fewer needle drops (0.4 ± 0.7 vs. -0.5 ± 0.9, P = 0.06). The 3D annotation group scored significantly higher than the control group on the Global Evaluate Assessment of Robot Skills (16.8 ± 2.0 vs. 22.8 ± 2.4, P = 0.04). The 3D annotation group also scored higher than the voice (13.4 ± 1.2) and 2D annotation (16.2 ± 1.8) groups (3D vs. voice: P = 0.03, 3D vs. 2D: P = 0.03). Telementoring using 3D drawing annotation was shown to provide good comprehension and a smooth operation for local surgeons.

Accuracy of Preoperative 3D vs 2D Digital Templating for Cementless Total Hip Arthroplasty Using a Direct Anterior Approach

BackgroundAn important aspect of preoperative planning for total hip arthroplasty is templating. Although two-dimensional (2D) templating remains the gold standard, computerized tomography (CT)-based three-dimensional (3D) templating is a novel preoperative planning technique. This study aims to compare the accuracy of a 2D and 3D plan using an anterior approach for the placement of the same uncemented prosthesis. MethodsTwo consecutive cohorts of 100 patients each were retrospectively analyzed. We analyzed the accuracy of the size of the implant (stem, cup, head), the length of head, and offset. As a secondary criterion, we analyzed the rates of stems with more than 3° of varus, fracture, and/or subsidence at 3 months postoperatively. ResultsWithin the exact size, the accuracy of the stem and cup size with the 2D plan was 69% and 56%, respectively. With the 3D plan accuracy being 88% (P = .0046) and 96% (P < .0001), respectively. Regarding size and length of the implant head, accuracy was 86% and 82% with the 2D plan and 100% (P < .0001) and 94% (P = .016), respectively, with the 3D plan. The offset of the implants increased beyond 3 mm in 23% of patients in the 2D group and in 5% of patients in the 3D group (P = .0003). The rate of varus stems was 10% in the 2D group and 2% in the 3D group (P = .03). Two fractures and one case of subsidence occurred in the 2D group. None were identified in the 3D cohort. ConclusionsA CT-based 3D plan is more accurate for implant size selection, allows better prosthetic offset, and reduces the rate of varus stems.

A Randomized Trial of Dolutegravir Plus Darunavir/Cobicistat as a Switch Strategy in HIV-1-Infected Patients With Resistance to at Least 2 Antiretroviral Classes.

Suppressed patients with drug-resistant HIV-1 require effective and simple antiretroviral therapy to maintain treatment adherence and viral suppression. This randomized, open-label, noninferiority, multicenter pilot study involved HIV-infected adults who met the following criteria: confirmed HIV-1 RNA <50 copies/mL for ≥6 months preceding the study randomization, treatment with at least 3 antiretroviral drugs, and a history of drug resistance mutations against at least 2 antiretroviral classes but remaining fully susceptible to darunavir (DRV) and integrase inhibitors. Participants were randomized 1:1 to switch to dolutegravir (DTG; 50 mg once per day) plus DRV boosted with cobicistat (DRV/c; 800/150 mg once per day; 2D group) or continue with their baseline regimen (standard-of-care [SOC] group). The primary endpoint was the proportion of patients with HIV-1 RNA <50 copies/mL at week 48 relative to time to loss of virologic response, with a noninferiority margin set at -12.5%. Virologic failure was defined as confirmed HIV-1 RNA ≥50 copies/mL or a single determination of HIV-1 RNA >50 copies/mL followed by antiretroviral therapy discontinuation. Forty-five participants were assigned to the 2D group and 44 to the SOC group. Time to loss of virologic response showed no difference in the proportion maintaining HIV-1 RNA <50 copies/mL at week 48: 39 of 45 (86.7%; 95% CI, 73.21%-94.95%) in the 2D group vs 42 of 44 (95.4%; 95% CI, 84.53%-99.44%) in the SOC group (log-rank P = .159) with an estimated difference of -8.7 (95% CI, -22.72 to 5.14). Only 2 (4.5%) in the SOC group experienced virologic failure, and 3 participants from the 2D group experienced adverse events leading to treatment discontinuation. In suppressed patients with at least 2 resistant antiretroviral classes, noninferiority could not be demonstrated by fully active DRV/c plus DTG. Nevertheless, there were no unexpected adverse events or virologic failure. DRV/c plus DTG may be considered a once-daily therapy option only for well-selected patients. Clinical Trials Registration. ClinicalTrials.gov (NCT03683524).

Three-dimensional lung reconstructions for the localization of lung nodules to be resected during surgery.

The localization of lung nodules is challenging during thoracoscopy. In this study, we evaluated the use of three-dimensional (3D) lung reconstruction for use in the operating room to guide the identification of lung nodules during thoracoscopy. This was a single-center retrospective study. All consecutive patients undergoing thoracoscopic resection of lung nodules were included in the study. Patients were retrospectively divided into two groups based upon whether the thoracoscopic resection was performed with the assistance (3D group) or not (standard group) of 3D lung reconstruction. The operative time (minutes) to detect lung nodules was statistically compared between the two study groups in relation to the characteristics of lung nodules as size, localization, and distance from the visceral pleura. Our study population consisted of 170 patients: 85 in the 3D group and 85 in the standard group. No intergroup difference differences were found regarding the characteristics and histological diagnosis of lesions. The standard group compared to the 3D group was associated with a significantly longer operative time for the detection of lesions <10 mm (13.87 ± 2.59 vs. 5.52 ± 1.01, p < 0.001), lesions between 10 and 20 mm (5.05 ± 0.84 vs. 3.89 ± 0.92; p = 0.03), lesions localized in complex segments (7.49 ± 4.25 vs. 5.11 ± 0.97; p < 0.001), and deep lesions (9.58 ± 4.82 vs. 5.4 ± 1.01, p < 0.001). Our 3D lung reconstruction model for use in the operating room may be an additional tool for thoracic surgeons to guide the detection of small and deep nodules during thoracoscopy. It is a noninvasive and cost saving procedure and may be widely used.

Three-dimensional printed cast assisted screw fixation of calcaneal fractures: a prospective study

BackgroundTreatment of displaced intra-articular calcaneal fractures (DIACFs) with percutaneous screw fixation remains defective in some aspects. A novel three-dimensional (3D) printed cast was devised to assist screw placement. This study assessed the radiological and functional outcomes of 3D-printed cast assisted screw fixation for patients with DIACFs.MethodsPatients with unilateral Sanders type II or III DIACFs admitted to a single-centre hospital underwent either 3D-printed cast assisted screw fixation (3D group) or minimally invasive plate fixation (control group) from September 2020 to November 2022. All patients were assessed at one, two, three, and six months of follow-up. Comparison between groups was conducted in operative duration, fluoroscopic times, radiographic measurements of the calcaneus, and the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score.ResultsA total of 32 patients were enrolled (19 in the 3D group versus 13 in the control group). Significant differences were detected between the 3D group and control group in operative duration (53.63±8.95 min, 95.08±8.31 min, P <0.001), fluoroscopic times (7.37±1.21, 16.85±1.57, P <0.001). At a follow-up of six months, the 3D group showed better restoration than the control group in calcaneal width, height, Bohler angle, and AOFAS Ankle-Hindfoot scores (all P <0.001). No significant differences were shown in calcaneal length and Gissane angle (P >0.05). No wound-related complications occurred in either group.ConclusionThe 3D-printed cast assisted screw fixation has shown superiority over minimally invasive plate fixation in the operative duration, fluoroscopic exposure, morphological restoration of the calcaneus, and functional outcomes in the treatment of DIACFs.

3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture

PurposeThis study aimed to compare the effects of conventional surgery and three-dimension (3D) printing technology-assisted surgery in the treatment of posterolateral tibial plateau fractures (PTPF).MethodsA cohort of 61 patients afflicted with PTPF, spanning from June 2015 to October 2021, was enrolled. They were divided randomly into two groups: 31 cases of 3D printing group, 30 cases of conventional group. The personalized 3D-printed models were used to simulate the surgical procedures in 3D printing group. The demographic characteristics and clinical data were recorded, encompassing operation duration, intraoperative blood loss, intraoperative fluoroscopy shoots and fracture union time. The radiographic outcomes were gauged, encompassing tibiofemoral angle (FTA), tibial plateau angle (TPA), posterolateral slope angle (PSA) and Rasmussen’s anatomical score. The functional outcomes were assessed at the 12-month postoperative juncture, encompassing range of motion, Hospital for Special Surgery (HSS) score and Rasmussen’s functional score. Furthermore, fracture complications were evaluated,, encompassing infections, traumatic osteoarthritis, and delayed union.ResultsThe 3D printing group exhibited the operation time of 95.8 ± 30.2 min, intraoperative blood loss of 101.1 ± 55.3 ml, and intraoperative fluoroscopy shoots of 6.3 ± 2.3 times, while the conventional group recorded respective values of 115.5 ± 34.0 min, 137.0 ± 49.2 ml and 9.13 ± 2.5 times. Noteworthy disparities were evident between the conventional and 3D printing groups (p < 0.05). Furthermore, in comparison to the conventional group, the 3D printing group exhibited commendable radiological and functional outcomes both immediately and 12 months post-surgery, although statistical significance was not attained. Moreover, the 3D printing group experienced a paucity of complications compared to the conventional group, although without achieving statistical significance.ConclusionThis study demonstrated the clinical feasibility of 3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture.

Enhancing surgical precision and efficiency: a study and comparison of a three-dimensional surgical video system in proliferative diabetic retinopathy surgery.

This study aimed to investigate the safety and efficacy of three-dimensional (3D) surgical video systems for proliferative diabetic retinopathy (PDR). This retrospective clinical case study included 30 patients (30 eyes) with PDR. Patients were divided into two groups: one underwent surgery using a 3D surgical video system (14 cases, 14 eyes), while the other underwent traditional microscope surgery (16 cases, 16 eyes). Safety and efficacy were assessed through predetermined surgical parameters, including surgical duration, intraoperative membrane removal rate, and occurrences during intraoperative and postoperative phases. Our study revealed noteworthy differences in various aspects between the 3D surgical video system group and the traditional microscope surgery group. Specifically, the mean surgical time was 30.25 ± 14.43 mins in the 3D surgical video system group, while it was 38.56 ± 18.71 mins in the traditional microscope surgery group (p = 0.051). Furthermore, the mean membrane removal time was significantly shorter in the 3D group at 2.53 ± 1.52 mins, as compared to 3.23 ± 1.76 mins in the traditional group (p = 0.042). Importantly, the membrane removal rate also displayed a significant difference, with the 3D group at 0.55 ± 0.07 and the traditional group at 0.41 ± 0.11 (p = 0.018). However, no notable differences were observed between the two groups in terms of intraoperative and postoperative incidences. The safety and efficacy obtained using the 3D surgical video system in PDR surgery were comparable to those obtained in traditional microscopic surgery.

The use of mobile applications in logistics of services

The article focuses on the importance of mobile applications in enterprises with a focus on logistics in the service sector. In the theoretical part, individual software applications in the field of occupational health and safety, fire protection, which are used in Slovakia and the Czech Republic are clearly described. The article contains a brief overview of the legislative regulations on the basis of which the obligations for management decisions in enterprises arise. A telephone survey was conducted in 110 micro, small and medium-sized enterprises between 2022 and 2023 in order to determine the use of software solutions in ensuring the fulfilment of obligations in the field of occupational safety and health and fire protection. To collect data, research questions were set and a questionnaire was developed, which included 6 merit questions, identification questions and a specific question aimed at finding out the prioritisation of the most preferred mobile application features in the study area. The questions were closed-ended, with options where the respondent could choose only one answer. SPSS for Windows version 21.0 was used for statistical analysis and processing of the collected data. We used methods of statistical description, analysed using relative abundance, arithmetic mean, standard deviation and median. At the level of statistical inference, we used chi-square goodness-of-fit tests to analyse categorical variables. We also used nonparametric tests, Friedman analysis of variance, 3D pie charts, and 3D group bar charts. We found that business representatives had a significantly higher preference for the functionality "record of initial and recurrent BOZP and PO training", followed by the second most preferred functionality "OSH inspections and fire prevention inspections". The research focused on logistics enterprises.

Software for Animation and Graphic Visualization of Mechatronic Elements and Control Process of FMS

The issue of graphical visualization of the simulation, animation and design of mechatronic elements and control process in the example of the mechanical assembly shop of the flexible manufacture system (FMS), which is considered a complex technical system, is set. The purpose of the work is the development of graphics-mode software that provides computer experiments of 2D, 3D designer-modeling, animation and graphic visualization of the interface for evaluating the feasibility of the design process of the flexible mechanical assembly cell (FMAC) As the main research issues, the construction of the 2D and 3D grouping scheme of the static and dynamic elements of the research object, the development of 3D software for the animation models of the activities of its active elements, and the development of the generalized software for the graphic visualization of the interface for the design of the management system were set. Based on the issues raised, the 3D grouping scheme of static and dynamic elements of the FMAC was established, the positioning coordinates of the 2D static and dynamic elements of the FMAC were determined in the PROOF Animation system, the analysis of the technological process of the FMS was carried out to build an animation model, and the animation movements of technological operations were MOVE (management unguided movement) or PATH (guided movement) operators. An animation model of the static and dynamic active elements of the FMAC was built, experiments were conducted, and as a result, it was possible to calculate a technological cycle in the research object and determine the productivity of the workshop. The software for the graphic visualization of the design of the control system of the FMAC was developed, and the procedures and operations of each software module of the interface were planned.

A clinical study of the effect of 3D reconstruction on exophthalmos after an operation on an old orbital wall fracture.

Orbital blowout fracture is common in ocular trauma. Accurate measurement of orbital volume after fracture is key in improving intraocular correction. This study aims to explore the impact of 3D reconstruction technology in restoring normal exophthalmos in patients with old orbital wall fractures. A total of 31 patients were randomly divided into an experimental group (n= 15) and a control group (n= 16). For orbital wall repair and reconstruction, the conventional group used the conventional surgical scheme, and the 3D group used 3D printing technology. There was no statistical difference between the preoperative mean extraocular muscle volume of the healthy eye and the affected eye. However, the mean orbital volume (24.76 vs 27.11, P= 0.005) and mean retrobulbar fat volume (17.53 vs 16.42, P= 0.006) were significantly different between the healthy eye and the affected eye. After an average follow-up of 16 weeks, the differences in pre- and post-surgery exophthalmos in the two groups were 0.42 ± 0.08 mm and 1.63 ± 0.51 mm, respectively. The difference between the two groups was statistically significant (t= 4.42, P= 0.003). The complications were not statistically different. Using 3D reconstruction technology preoperatively can significantly improve exophthalmos in patients with old orbital wall fractures.

Mechanical properties of 3D-printed and milled composite resins for definitive restorations: An in vitro comparison of initial strength and fatigue behavior.

To evaluate the flexural strength and fatigue behavior of a novel 3D-printed composite resin for definitive restorations. Fifty disc-shaped specimens were manufactured from each of a nanohybrid composite resin (NHC), polymer-infiltrated ceramic network (PICN), and 3D-printed composite resin (3D) with CAD-CAM technology. Biaxial flexural strength (σin ) (n = 30 per group) and biaxial flexural fatigue strength (σff ) (n = 20 per group) were measured using piston-on-three-balls method, employing a staircase approach of 105 cycles. Weibull statistics, relative-strength degradation calculations, and fractography were performed. The results were analyzed with 1-way ANOVA and Games-Howell post hoc test (α = 0.05). Significant differences in σin and σff among the groups (p < 0.001) were detected. The NHC group provided the highest mean ± standard deviation σin and σff (237.3 ± 31.6 MPa and 141.3 ± 3.8 MPa), followed by the PICN (140.3 ± 12.9 MPa and 73.5 ± 9.9 MPa) and the 3D (83.6 ± 18.5 MPa and 37.4 ± 23.8 MPa) groups. The 3D group exhibited significantly lower Weibull modulus (m = 4.7) and up to 15% higher relative strength degradation with areas of nonhomogeneous microstructure as possible fracture origins. The 3D-printed composite resin exhibited the lowest mechanical properties, where areas of nonhomogeneous microstructure developed during the mixing procedure served as potential fracture origins. The clinical indications of the investigated novel 3D-printed composite resin should be limited to long-term provisional restorations. A cautious procedure for mixing the components is crucial before the 3D-printing process, since nonhomogeneous areas developed during the mixing could act as fracture origins.

745 The Effect of 3D Versus 2D Training Models in Laparoscopic Skills Acquisition: A Randomised Controlled Trial of Novice Medical Students

Abstract Aim Determining whether the effect of laparoscopic technical skills acquisition will be superior with the use of low-fidelity 3D training models with contours compared to flat, 2D LapPass training models in novice medical students. Method This was a prospective, single-centre, two-arm, randomised controlled trial. Participants were randomised equally into either 3D or 2D group and performed two standardised laparoscopic tasks: (1) grasping and manipulation and (2) intracorporeal suturing on separate days. Performance was based on the GOALS tool, completion time and number of errors via 3 assessments (baseline, interim and post-training) each session. A post-study survey was used to measure participant-perceived confidence and performance. Results Sixty-two participants completed the study from April to June 2022. The two groups were homogenous regarding demographic data (p&amp;gt;0.05). Both groups had significantly superior performance post-training compared to baseline in the two tasks via the intra-group comparison (p&amp;lt;0.017). In the inter-group comparison, the 3D group had statistically significantly greater improvements in GOALS score parameter and depth perception domain in all comparisons in the two tasks (p&amp;lt;0.05). The time improvement and error reduction also favoured the 3D group. In the post-study survey, the 3D group reported significantly greater perceived post-training confidence and performance in the suturing task only (p&amp;lt;0.05). Conclusions The 3D training models resulted in a superior laparoscopic skills acquisition for novices in two tasks compared to 2D LapPass training models and should be incorporated into laparoscopic training curricula. Further work should focus on their long-term efficacy on a competency-based endpoint.