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Purpose: This study aimed to compare long-term clinical and radiographic outcomes and survival rates between navigation-assisted (NAV) total knee arthroplasty (TKA) and conventional (CON) TKA using a mobile-bearing insert., Methods: From May 2008 to December 2009, 45 and 63 mobile-bearing TKA patients were enroled in the CON- and NAV-TKA groups with 146.8 months follow-up, respectively. Clinical outcomes (Western Ontario and McMaster University Osteoarthritis Index and Knee Society Scores), radiographic outcomes (hip-knee-ankle [HKA], lateral distal femoral, medial proximal tibial, γ, and δ angles), and survivorship were compared between both groups., Results: The number of HKA angle outliers (more than 3 degrees or less than -3 degree) was significantly lower in the NAV-TKA group (24.4% vs. 9.5%, p = 0.036) than in the CON-TKA group. However, long-term clinical outcomes were similar between both groups. The cumulative survival rate (best-case scenario) was 98.3% in the CON-TKA group and 97.5% in the NAV-TKA group, with no significant difference between the groups (p = 0.883)., Conclusion: Long-term clinical outcomes and survival rates were similar between the two groups despite fewer outliers of postoperative lower-limb alignment in the NAV-TKA group. Excellent survival rates were observed in both groups using mobile-bearing inserts., Level of Evidence: Level IV, case series., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: To determine whether patient-specific instrumentation (PSI), computer-assisted surgery (CAS) or robot-assisted surgery (RAS) enable more accurate rotational alignment of the tibial baseplate in primary total knee arthroplasty (TKA) compared to conventional instrumentation, in terms of deviation from the planned target and the proportion of outliers from the target zone., Methods: The authors independently conducted three structured electronic literature searches using the PubMed, Embase®, and Cochrane Central Register of Controlled Trials databases from 2007 to 2020. Studies were included if they compared rotational alignment of the tibial baseplate during TKA using conventional instrumentation versus PSI, CAS, and/or RAS, and reported deviation from preoperatively planned rotational alignment of the tibial baseplate in terms of absolute angles and/or number of outliers. Methodological quality of eligible studies was assessed by two researchers according to the Downs and Black Quality Checklist for Health Care Intervention Studies., Results: Fifteen studies, that reported on 2925 knees, were eligible for this systematic review, of which 6 studies used PSI, and 9 used CAS. No studies were found for RAS. Of the studies that reported on angular deviation from preoperatively planned rotational alignment, most found smaller deviations using PSI (0.5° to 1.4°) compared to conventional instrumentation (1.0° to 1.6°). All studies that reported on proportions of outliers from a target zone (± 3°), found lower rates of outliers using PSI (0 to 22%) compared to conventional instrumentation (5 to 96%). Most studies reported smaller angular deviation from preoperatively planned rotational alignment using CAS (0.1° to 6.9°) compared to conventional instrumentation (1.1° to 7.8°). Of the studies that reported on proportions of outliers from a target zone (± 3°), most found fewer outliers using CAS (10 to 61%) compared to conventional instrumentation (17 to 78%)., Conclusion: This systematic review and meta-analysis revealed that both CAS and PSI can improve the accuracy of rotational alignment of the tibial baseplate by decreasing angular deviation from the preoperatively planned target and reducing the proportion of outliers from the target zone. The clinical relevance is that PSI and CAS can improve alignment, though the thresholds necessary to grant better outcomes and survival remain unclear., Level of Evidence: IV., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Objectives: To evaluate the performance of the nnU-Net open-source deep learning framework for automatic multi-task segmentation of craniomaxillofacial (CMF) structures in CT scans obtained for computer-assisted orthognathic surgery., Methods: Four hundred and fifty-three consecutive patients having undergone high-resolution CT scans before orthognathic surgery were randomly distributed among a training/validation cohort (n = 300) and a testing cohort (n = 153). The ground truth segmentations were generated by 2 operators following an industry-certified procedure for use in computer-assisted surgical planning and personalized implant manufacturing. Model performance was assessed by comparing model predictions with ground truth segmentations. Examination of 45 CT scans by an industry expert provided additional evaluation. The model's generalizability was tested on a publicly available dataset of 10 CT scans with ground truth segmentation of the mandible., Results: In the test cohort, mean volumetric Dice similarity coefficient (vDSC) and surface Dice similarity coefficient at 1 mm (sDSC) were 0.96 and 0.97 for the upper skull, 0.94 and 0.98 for the mandible, 0.95 and 0.99 for the upper teeth, 0.94 and 0.99 for the lower teeth, and 0.82 and 0.98 for the mandibular canal. Industry expert segmentation approval rates were 93% for the mandible, 89% for the mandibular canal, 82% for the upper skull, 69% for the upper teeth, and 58% for the lower teeth., Conclusion: While additional efforts are required for the segmentation of dental apices, our results demonstrated the model's reliability in terms of fully automatic segmentation of preoperative orthognathic CT scans., Key Points: • The nnU-Net deep learning framework can be trained out-of-the-box to provide robust fully automatic multi-task segmentation of CT scans performed for computer-assisted orthognathic surgery planning. • The clinical viability of the trained nnU-Net model is shown on a challenging test dataset of 153 CT scans randomly selected from clinical practice, showing metallic artifacts and diverse anatomical deformities. • Commonly used biomedical segmentation evaluation metrics (volumetric and surface Dice similarity coefficient) do not always match industry expert evaluation in the case of more demanding clinical applications., (© 2021. The Author(s), under exclusive licence to European Society of Radiology.)

Purpose: The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes., Methods: One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively., Results: There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group., Conclusion: The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI., Level of Evidence: Randomised controlled trial, level I., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: Medial open-wedge high tibial osteotomy (MOWHTO) is an accepted option in the treatment of medial compartment osteoarthritis of the knee in young and active patients. Functional results are closely correlated to the correction of the mechanical axis of the lower limb. Although several angular and geometrical methods and values have been proposed in the past, the ideal target is still debated. In addition, it is important to have a deep correlation between the planned correction and the achieved correction after surgery. The aim of the present systematic review was to identify the ideal coronal correction after MOWHTO and the most accurate method to achieve it., Methods: A systematic review of the literature was completed on July 3rd 2020 in the Pubmed, Medline, Cochrane Reviews, and Google Scholar databases using the Medical Subject Headings (MeSH) terms: "high tibial osteotomy" AND "accuracy" OR "planning"., Results: 28 studies were included; 18 were focused on computer-assisted surgery (CAS) and 10 on patient-specific instrumentation (PSI). There were 598 patients in the CAS group and 501 in the control group; the rate of outliers was 16% and 38.2% respectively (P = 0.04), while there was no significant difference between the two groups (SMD = - 0.10; 95% CI 1.31 to 1.12; P = n.s.) in terms of coronal accuracy. Likewise, there were 318 patients in the PSI group and 40 in the control group; the rate of outliers was 15% and 40% respectively (P = 0.98), while there was no significant difference between the two groups (SMD = 0.01; 95% CI 0.58 to 0.59; P = 0.98)., Conclusions: A statistically significant reduced outlier rate and a non-significant increased accuracy emerged with the use of CAS when compared to the traditional surgical technique, whereas the results of PSI were still inconclusive. In addition, it emerged clearly that no consensus still exists on the ideal correction target to be achieved after surgery., Level of Evidence: III., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: Correct positioning and alignment of the prosthesis is a very important factor for durability of prosthesis and implant survival which is improved with the use of technology in total knee arthroplasty. However, the long-term functional outcomes and survivorship are unclear. For this study, it was hypothesized that mechanical axis alignment of lower limb, post-operative joint line restoration, femoral and tibial component alignment is more accurate with the new handheld semi-active robotic-assisted TKA., Method: From April-2019 to March-2020, 60 patients with unilateral knee osteoarthritis who underwent total knee arthroplasties were included in this prospective randomised controlled study. Computer generated randomization was used. Study included 48 female patients and 12 male patients. Pre-operative and post-operative radiographic measurements were done and compared between the two groups., Results: There was a significant difference between two groups with respect to mechanical axis deviation, joint line deviation and coronal alignment of femoral and tibial prosthesis. Mechanical axis deviation > 3° was seen in eight cases (28.5%) in C-TKA group compared to one case (3.1%) in RA-TKA (p 0.019). Joint line deviation of 3.5 mm was noted in C-TKA group as compared to 0.9 mm in RA-TKA group (p < 0.001) which was statistically significant. However, whether this difference of 2.6 mm of joint line elevation between C-TKA and RA-TKA leads to any difference in clinical outcome in terms of knee kinematics and knee flexion needs to be investigated with further studies. Clinically restoring normal joint line is important for improved knee function after primary TKA. No significant difference was noted in femoral component rotation on post-operative computed tomography (CT) scan., Conclusion: The novel imageless, handheld semi-autonomous robotic system for TKA is highly accurate with respect to component positioning in coronal plane and mechanical alignment as compared to conventional TKA. Joint line is elevated in conventional TKA but is accurately restored using the robotic-assisted TKA which may lead to better patellofemoral kinematics., Level of Evidence: I., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The percutaneous nephrolithotomy (PCNL) has become the gold-standard for treating patients with the larger renal stones and staghorn calculi. This study was designed to evaluate the outcomes of flank versus prone position in patients underwent ultrasonic-guided PCNL for treatment of large kidney stones., Methods: This prospective randomized clinical trial was conducted from September 2017 to September 2019 in the department of Urology, Labbafinejad University hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Two hundred patients with kidney stones larger than 2 cm underwent PCNLs in prone (n = 100) or flank position (n = 100). Success rate, operative time, access time, hemoglobin and creatinine changes, hospital stay, auxiliary procedure and surgical complications were compared between the two groups., Results: The two groups were similar in their baseline characteristics. The success rates in prone (87%) versus flank position (85%) were not significantly different at the first post-operative follow-up (p = 0.91). At the three-month follow-up, the overall stone free rates for the prone position PCNLs and flank position PCNLs were 94/100 (94%) and 90/100 (90%) (p = 0.96). There were no significant difference between the groups in operative time (p = 0.42), access time (p = 0.66), hemoglobin (p = 0.46) and creatinine (p = 0.22) changes, hospital stay (p = 0.05), auxiliary procedures (p = 0.75) and surgical complications., Conclusion: Overall, there is no significant difference between prone and flank positions in success rate and complications. More prospective studies must be carried out to identify patient populations who are most apt to benefit from one position over the other., Trial Registration Number: IRCT20200902048597N1 DATE OF REGISTRATION: 2020-11-21, retrospectively registered., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To explore the treatment of pediatric hepatic hemangioma and the role of the Hisense computer-assisted surgery (Hisense CAS) system in diagnosis and treatment., Methods: We collected the clinical and follow-up data of all pediatric hepatic hemangioma cases in our pediatric surgery department from March 2008 to March 2021 for retrospective analysis. The Hisense CAS system was used to create three-dimensional (3D) reconstructions based on computed tomography data., Results: There were 71 patients, mainly infants (prenatal to 39 months). There were more males than females (42 vs. 29), and the alpha-fetoprotein level was significantly increased in 8 cases. 3D reconstruction by the Hisense CAS system showed that hepatic artery tracking was helpful for the differential diagnosis of pediatric hepatic hemangioma. Twenty-three children treated with propranolol showed significant differences in the tumour diameter, volume, and tumour-to-liver volume ratio after treatment (all P < 0.05). Compared with early surgical treatment, the curative effect of this approach was obvious., Conclusion: As a non-surgical treatment for symptomatic pediatric hepatic hemangioma, propranolol can replace surgical resection to a certain extent and reduce the proportion of children who need surgical intervention. Hisense CAS has advantages in evaluating the tumour volume before and after propranolol treatment. The liver volume and the liver tumour volume percentage provide new perspectives for evaluating the tumour outcome., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aimed to standardize the operative technique of indocyanine green (ICG) near-infrared fluorescence (NIRF) laparoscopic partial nephrectomy (LPN) and compare it with the standard technique., Methods: In the last 4 years, we performed 22 LPN (14 right-sided, 8 left-sided) in children with non-functioning moiety of duplex kidney. Patients included 12 girls and 10 boys with a median age of 3.9 years (range 1-10). Patients were grouped according to the use of ICG-NIRF: G1 included 12 patients operated using ICG-NIRF and G2 included 10 patients receiving the standard technique. We standardized the technique of injection of ICG in three different steps., Results: The median operative time was significantly lower in G1 [87 min (range 68-110)] compared with G2 [140 min (range 70-220)] (p = 0.001). One intra-operative complication occurred in G2. At post-operative ultrasound (US), the residual moiety was normal in all patients. An asymptomatic renal cyst related to the site of surgery was visualized at US in 8/22 (36%), with a significantly higher incidence in G2 (6/10, 60%) compared with G1 (2/12, 16.6%) (p = 0.001). Renogram demonstrated no loss of function of residual moiety. No allergic reactions to ICG occurred., Conclusion: ICG-NIRF LPN is technically easier, quicker, and safer compared with the standard technique. The main advantages of using ICG-NIRF during LPN are the clear identification of normal ureter, vasculature of non-functioning pole, and demarcation line between the avascular and the perfused pole. The main limitation of ICG technology remains the need for specific laparoscopic equipment that is not always available., (© 2021. The Author(s).)

Purpose: The aim of this study was to determine the impact and cost-effectiveness of virtual surgical planning during fibula free flap mandibular reconstruction on peri- and postoperative data., Methods: We conducted a retrospective cohort study from January 2012 to December 2016 in four French university centres., Results: Three hundred fibula free flaps for mandibular reconstruction were performed in 294 patients. Surgeries were planned in 29.7% of cases (n = 89). There was no significant difference in the rate of negative-margins excision, median length of hospital stay, operative time, and early complications between planned and non-planned surgeries. Morphological analysis revealed a higher rate of centred occlusion in planned patients (satisfactory alignment of interincisal points: Planned 65.5% vs Non-Planned 33.3%, p = 0.006)., Conclusion: In mandibular reconstruction by fibula free flap, the additional cost generated by virtual surgical planning does not seem to be balanced by savings resulting from a shorter operative course, a reduced hospital stay, or a reduction in postoperative complications. However, virtual surgical planning may provide a higher rate of centred occlusion. Long-term benefits should be assessed by further studies., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Purpose: The ultrasound-guided (US) puncture in percutaneous nephrolithotomy (PCNL) has demonstrated advantages over traditional fluoroscopy access. The aim of this study was to demonstrate the reduction of fluoroscopy time using this technique during PCNL as the surgeon gained experience., Methods: Transversal study performed on 30 consecutive patients undergoing PCNL from March to November 2019. All punctures were performed with US guidance. The patients were divided into 2 groups of 15 each according to the chronological order of the intervention. Demographic data, preoperative parameters, puncture time, fluoroscopy time, stone-free rate and complications were analyzed., Results: The time of fluoroscopy was considerably reduced as the experience in the number of cases increased, reducing from 83.09 ± 47.8 s in group 1 to 22.8 ± 10.3 s in group 2 (p < 0.01), the time required to perform the puncture was reduced of 108.1 ± 68.9 s in group 1, to 92.6 ± 94.7 s in group 2 (p < 0.67). Stone free rate of 83.3% was obtained globally., Conclusion: US percutaneous renal access is safe and reproducible technique; the main advantage is to reduce exposure to radiation without compromising clinical results and has a short learning curve for urologists with prior experience in PCNL., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Overview: The goal of this study was to review the current application and status of three-dimensional printing for craniosynostosis surgery., Methods: A literature review was performed using the PubMed/MEDLINE databases for studies published between 2010 and 2020. All studies demonstrating the utilization of three-dimensional printing for craniosynostosis surgery were included., Results: A total of 15 studies were ultimately selected. This includes studies demonstrating novel three-dimensional simulation and printing workflows, studies utilizing three-dimensional printing for surgical simulation, as well as case reports describing prior experiences., Conclusion: The incorporation of three-dimensional printing into the domain of craniosynostosis surgery has many potential benefits. This includes streamlining surgical planning, developing patient-specific template guides, enhancing residency training, as well as aiding in patient counseling. However, the current state of the literature remains in the validation stage. Further study with larger case series, direct comparisons with control groups, and prolonged follow-up times is necessary before more widespread implementation is justified., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The purpose of this study is to report a new mini-invasive technique to remove an intracranial bullet in a child by using O-arm for intraoperative neuronavigation., Case Report: A 14-year-old refugee boy had suffered a shooting injury 4 years earlier. O-arm imaging-assisted neuronavigation during craniotomy was performed in order to remove a bullet from the intracranial space in a paediatric patient., Conclusion: Navigation using O-arm is a feasible method in removing a foreign material in a child and gave an accurate location of the bullet in the adopted surgical operation position without significant imaging artefacts., (© 2020. The Author(s).)

Purpose: Augmented reality improves planning and execution of surgical procedures. The aim of this study was to evaluate the feasibility of a 3D augmented reality hologram in live parotic surgery. Another goal was to develop an accuracy measuring instrument and to determine the accuracy of the system., Methods: We created a software to build and manually align 2D and 3D augmented reality models generated from MRI data onto the patient during surgery using the HoloLens ® 1 (Microsoft Corporation, Redmond, USA). To assess the accuracy of the system, we developed a specific measuring tool applying a standard electromagnetic navigation device (Fiagon GmbH, Hennigsdorf, Germany)., Results: The accuracy of our system was measured during real surgical procedures. Training of the experimenters and the use of fiducial markers significantly reduced the accuracy of holographic system (p = 0.0166 and p = 0.0132). Precision of the developed measuring system was very high with a mean error of the basic system of 1.3 mm. Feedback evaluation demonstrated 86% of participants agreed or strongly agreed that the HoloLens will play a role in surgical education. Furthermore, 80% of participants agreed or strongly agreed that the HoloLens is feasible to be introduced in clinical routine and will play a role within surgery in the future., Conclusion: The use of fiducial markers and repeated training reduces the positional error between the hologram and the real structures. The developed measuring device under the use of the Fiagon navigation system is suitable to measure accuracies of holographic augmented reality images of the HoloLens.

Purpose: To present the first known pediatric utilization of cone-beam navigation system (CBNS) for hemivertebra resection and spondylodesis CASE PRESENTATION: A 14-year-old female with congenital scoliosis, diagnosed at 8 years of age, presenting with progressive symptoms, a Cobb angle (L3-5) of 38° at time of surgery, treated historically with conservative measures. Presence of spinal intramedullary disease was excluded prior to operation via whole spine MRI., Results: Patient successfully underwent surgical correction utilizing the CBNS (O-arm™, Medtronic®). Post-operative Cobb angle (L3-5) was restored to 8°. Following four different pediatric patient's radiation exposures (two receiving correction via the O-arm platform and two via the traditional method employing fluoroscopy), we show a reduction in radiation exposure using the CBNS system., Conclusion: We present the first known pediatric case of the utilization of the CBNS system for hemivertebra correction. We demonstrate that utilizing the CBNS platform can not only increase surgical accuracy but also decrease pediatric patient's radiation exposure as a preoperative CT scan is not needed. Future studies should continue to explore additional benefits of implementing the system into surgical practice.

Objectives: To test the hypothesis that intraoperative cone beam computed tomography (CBCT) using the Allura augmented reality surgical navigation (ARSN) system in a dedicated hybrid operating room (OR) matches computed tomography (CT) for identification of pedicle screw breach during spine surgery., Methods: Twenty patients treated with spinal fixation surgery (260 screws) underwent intraoperative CBCT as well as conventional postoperative CT scans (median 12 months after surgery) to identify and grade the degree of pedicle screw breach on both scan types, according to the Gertzbein grading scale. Blinded assessments were performed by three independent spine surgeons and the CT served as the standard of reference. Screws graded as Gertzbein 0 or 1 were considered clinically accurate while grades 2 or 3 were considered inaccurate. Sensitivity, specificity, and negative predictive value were the primary metrics of diagnostic performance., Results: For this patient group, the negative predictive value of an intraoperative CBCT to rule out pedicle screw breach was 99.6% (CI 97.75-99.99%). Among 10 screws graded as inaccurate on CT, 9 were graded as such on the CBCT, giving a sensitivity of 90.0% (CI 55.5-99.75%). Among the 250 screws graded as accurate on CT, 244 were graded as such on the CBCT, giving a specificity of 97.6% (CI 94.85-99.11%)., Conclusions: CBCT, performed intraoperatively with the Allura ARSN system, is comparable and non-inferior to a conventional postoperative CT scan for ruling out misplaced pedicle screws in spinal deformity cases, eliminating the need for a postoperative CT., Key Points: • Intraoperative cone beam computed tomography (CT) using the Allura ARSN is comparable with conventional CT for ruling out pedicle screw breaches after spinal fixation surgery. • Intraoperative cone beam computed tomography can be used to assess need for revisions of pedicle screws making routine postoperative CT scans unnecessary. • Using cone beam computed tomography, the specificity was 97.6% and the sensitivity was 90% for detecting pedicle screw breaches and the negative predictive value for ruling out a pedicle screw breach was 99.6%.

Purpose: To determine the impact of intraoperative ultrasound on robotic-assisted radical nephrectomy with inferior vena cava (IVC) tumor thrombectomy in renal cell carcinoma (RCC)., Methods: We retrospectively analyzed intraoperative records of 27 patients with RCC and invasion of the IVC who underwent robotic-assisted nephrectomy with tumor thrombectomy at our center between December 2017 and July 2018. Diagnostic utility and impact of intraoperative transesophageal echocardiography (TEE), intraoperative robotic-assisted ultrasonography, and intraoperative contrast-enhanced ultrasound (CEUS) on surgical management were extracted from the surgical notes and intraoperative ultrasound reports., Results: Twenty-seven patients with thrombus had intraoperative ultrasound. Complete tumor removal was achieved in 22 patients, IVC transection in 5 patients, and no residual tumor was observed in all patients. Intraoperative TEE changed the robotic surgical strategy in three patients by monitoring thrombus-level regression. Downstaging of the thrombus level occurred in three patients: Levels IV to III in one and Levels III to II in two. Intraoperative robotic-assisted ultrasonography has facilitated safe VC clamp placement and identification and protection of collateral vessels during IVC transection in five patients. Intraoperative CEUS helped to differentiate the boundary between tumor thrombus (enhancement and small vessel pulsation) and bland thrombus (hypoechoic or no enhancement) in eight (29.6%) patients with bland thrombus., Conclusions: Intraoperative ultrasound is a safe, minimally invasive technique that can provide accurate real-time information regarding the presence and extent of IVC involvement and guidance for placement of a vena cava clamp, confirming the character of the thrombus to plan an optimal surgical approach.

Objectives: To investigate the predictive value of peritoneal carcinomatosis (PC) quantification by DWI in determining incomplete tumour debulking in ovarian carcinoma (OC)., Methods: Prospective patients with suspected stage III-IV or recurrent OC were recruited for DWI before surgery. PC on DWI was segmented semi-automatically by k-means clustering, retaining voxels with intermediate apparent diffusion coefficient (ADC) to quantify PC burden. A scoring system, functional peritoneal cancer index (fPCI), was proposed based on the segmentation of tumour volume in 13 abdominopelvic regions with additional point given to involvement of critical sites. ADC of the largest PC was recorded. The surgical complexity and outcomes (complete vs. incomplete tumour debulking) were documented. fPCI was correlated with surgical PCI (sPCI), surgical complexity, and its ability to predict incomplete tumour debulking., Results: Fifty-three patients with stage III-IV or recurrent OC were included with a mean age of 56.1 ± 11.8 years old. Complete tumour debulking was achieved in 38/53 patients (71.7%). Significant correlation was found between fPCI and sPCI (r > 0.757, p < 0.001). Patients with high-fPCI (fPCI ≥ 6) had a high surgical complexity score (p = 0.043) with 84.2% received radical or supra-radical surgery. The mean fPCI was significantly higher in patients with incomplete tumour debulking than in those with complete debulking (10.27 vs. 4.71, p < 0.001). fPCI/ADC combined with The International Federation of Gynecology and Obstetrics stage achieved 92.5% accuracy in predicting incomplete tumour debulking (AUC 0.947)., Conclusions: DWI-derived fPCI offered a semi-automated estimation of PC burden. fPCI/ADC could predict the likelihood of incomplete tumour debulking with high accuracy., Key Points: • Functional peritoneal cancer index (fPCI) derived from DWI offered a semi-automated estimation of tumour burden in ovarian carcinoma. • fPCI was highly correlated with surgical PCI (sPCI). • fPCI/ADC could predict the likelihood of incomplete tumour debulking with high accuracy.

Purpose: To perform a systematic literature review on the clinical impact of augmented reality (AR) for urological interventions., Methods: As of June 21, 2018, systematic literature review was performed via Medline, Embase and Cochrane databases in accordance with the PRISMA guidelines and registered at PROSPERO (CRD42018102194). Only full text articles in English were included, without time restrictions. Articles were considered if they reported on the use of AR during urological intervention and the impact on the surgical outcomes. The risk of bias and the quality of each study included were independently assessed using the standard Cochrane Collaboration risk of bias tool and the Risk Of Bias In Non-randomised Studies-of Interventions Tool (ROBINS-I)., Results: 131 articles were identified. 102 remained after duplicate removal and were critically reviewed for evidence synthesis. 20 studies reporting on the outcomes of the use of AR during urological interventions in a clinical setting were considered. Given the mostly non-comparative design of the studies identified, the evidence synthesis was performed in a descriptive and narrative manner. Only one comparative study was found, with the remaining 19 items being single-arm observational studies. Based on the existing evidence, we are unable to state that AR improves the outcomes of urological interventions. The major limitation of AR-assisted surgery is inaccuracy in registration, translating into a poor navigation precision., Conclusions: To date, there is limited evidence showing superior therapeutic benefits of AR-guided surgery when compared with the conventional surgical approach to the respective disease.

Purpose: To provide a comprehensive analysis about safety and efficacy of fluoroscopy-free total ultrasound-guided percutaneous nephrolithotomy (TUPN) versus ultrasound with fluoroscopy-guided percutaneous nephrolithotomy (UFPN)., Patients and Methods: 3-dimensional ultrasound-guided PCNL was retrospectively analyzed in 377 patients from 2015 to 2017. TUPN was performed in 185 patients and UFPN was finished in 192 patients. In TUPN group, the entire procedures of puncture and dilation were real-time monitored by three-dimensional ultrasound alone. Conversely, in UFPN group, the puncture was performed under the guidance of real-time ultrasound, while the dilation was monitored by fluoroscopy. Preoperative demographic data, intraoperative parameters and postoperative complications were compared., Results: Groups were comparable in baseline characteristics. Fifty percent of patients were Guy's score III-IV and over half of the patients were mild or none of hydronephrosis. All renal punctures were successfully performed. The primary successful rates of dilation were more than 95% in both groups (95.1% in TUPN and 95.8% in UFPN, p = 0.74). Two or more accesses were established in 33 patients (17.8%) in TUPN group and 25 patients (13%) in UFPN group (p = 0.20). Post-operative instant stone-free rates were 88.6% and 90.1%, TUPN versus UFPN, respectively, p = 0.65. Most of the complications were minor and there were no differences in Clavien-Dindo complications in both groups. Mean operating time and hospitalization were comparable., Conclusions: Our findings show that fluoroscopy-free total ultrasound-guided PCNL represents an alternatively safe and efficient approach for the treatment of renal stones. Further study will be required to evaluate fluoroscopy-free TUPN in various clinical settings.

Purpose: This study aimed to examine the accuracy of tibial implant alignment using an accelerometer-based portable navigation system in unicompartmental knee arthroplasty (UKA)., Methods: This retrospective matched case-control study reviewed 51 UKAs performed using an accelerometer-based portable navigation system, matched with 51 UKAs performed using conventional extramedullary rods. Coronal alignment and posterior slope of the tibial implant were measured on postoperative radiographs, and differences from preoperative planning were examined. Outliers and accuracy of tibial implant alignment were compared between the portable navigation and conventional groups using Fisher's exact test and Mann-Whitney U test, respectively., Results: In the portable navigation group, 100% of the implants were aligned within 3.0° of both target coronal and sagittal implant alignment. In the conventional group, 76.5% and 88.2% of the implants were within 3.0° of both target coronal and sagittal implant alignment. Statistical analysis revealed that outliers of coronal and sagittal alignment were significantly less in the portable navigation group than in the conventional group (P < 0.05). In addition, the absolute value difference between postoperative measurement and preoperative planning of both coronal and sagittal alignment was significantly smaller in the portable navigation group than in the conventional group (P < 0.05)., Conclusion: The portable navigation system improved the accuracy of tibial implant alignment in UKA. We found that 100% of the implants were aligned within 3.0° of both target coronal and sagittal implant alignment. The portable navigation system decreased the outliers of tibial coronal and sagittal alignment., Level of Evidence: Retrospective case-control study, Level III.

Purpose: The accuracy of patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) is still controversial, especially in the tibial prosthesis. It was hypothesized that the design modification of PSI improved the tibial prosthetic alignment and reduced the associated complications. The aim of this study was to compare the accuracy of a conventional PSI with that of a newly designed PSI for total knee arthroplasty (TKA) using a new three-dimensional (3D) measurement method., Methods: Thirty TKAs each using the conventional and newly designed PSIs were studied. The postoperative 3D-computed tomography (3D CT) image was superimposed on the preoperative 3D CT plan. The absolute differences in the tibial prosthetic alignment between the preoperative and postoperative 3D CT images were directly measured in the coronal, sagittal, and axial planes. Knees in which the difference in the prosthetic alignment was > 3° were considered deviations., Results: The new PSI showed less mean absolute differences and lower rate of deviations than the conventional PSI in the coronal and axial planes (p = 0.045 and p = 0.004, respectively). The deviations (> 3°) of the tibial prosthesis using the conventional PSI were 27, 30, and 63% and of those using the new PSI were 0, 20, and 20% in the coronal, sagittal, and axial planes, respectively., Conclusions: This is the first report to evaluate the effect of improvement in PSI design on the postoperative alignment using 3D method, and it clearly showed that the modification significantly improved the accuracy of alignment and reduced the deviations., Level of Evidence: Therapeutic study, case-control study, Level III.

Purpose: The purpose of this study was to test the hypotheses that the joint distraction force changes the three-dimensional articulation between the femur and the tibia and that the presence of posterior cruciate ligament (PCL) affects the three-dimensional articulation during joint gap evaluation in total knee arthroplasty (TKA)., Methods: Cruciate-retaining TKA procedures were performed on 6 cadaveric knees using a navigation system. The joint center gap and varus ligament balance were measured using Offset Repo-Tensor ® with the knee at 90° of flexion before and after PCL resection for joint distraction forces of 89, 178, and 266 N. The three-dimensional location of the tibia relative to the femur and the axial rotational angle of the tibia were also assessed., Results: Regardless of PCL resection, the joint center gap became larger (p = 0.002, p = 0.020) and varus ligament balance became more varus (p = 0.002, p = 0.002) with increasing joint distraction force, whereas the tibia was more internally rotated (p = 0.015, p = 0.009) and more anteriorly located (p = 0.004, p = 0.009). The tibia was more internally rotated (p = 0.015) and more posteriorly located (p = 0.026) after PCL resection than before resection., Conclusions: Joint distraction force changed three-dimensional articulation regardless of PCL preservation. PCL function was revealed as a factor restraining both tibial posterior translation and internal rotation. Surgeons should recognize that joint gap evaluation using a tensor device is subject to three-dimensional changes depending on the magnitude of the joint distraction force.

Purpose: Coronal correction errors after medial opening wedge high tibial osteotomy (MOWHTO) occasionally occur even with the assistance of navigation. The purpose of the present study was to determine the navigation accuracy in MOWHTO and to identify factors that affect the coronal correction error after navigation-assisted MOWHTO., Methods: A total of 114 knees treated with navigation-assisted MOWHTO were reviewed retrospectively. Mechanical axis (MA) on standing radiograph and medial proximal tibial angle (MPTA) were measured preoperatively and at 6 months postoperatively, and the differences (ΔMA and ΔMPTA) were calculated. Joint line convergence angle (JLCA) on supine and standing radiographs was measured preoperatively, and their difference (ΔJLCA) was calculated. To assess the navigation accuracy, ΔMA and ΔMPTA were compared with the coronal correction by navigation (ΔNMA) using intraclass correlation coefficients (ICCs). Univariable and multivariable regression analyses were used to identify factors that affect coronal correction discrepancy (ΔMA - ΔNMA)., Results: The reliability of navigation was good in terms of bony correction (ICC between ΔNMA and ΔMPTA, 0.844) and fair in terms of MA correction (ICC between ΔNMA and ΔMA, 0.706). The mean coronal correction discrepancy was 2.0° ± 2.4°. In the multivariable analysis, ΔJLCA was shown to be a predictive factor of coronal correction discrepancy (unstandardized coefficient, 1.026; R 2 , 0.470)., Conclusion: Navigation in MOWHTO provided reliable information about bony correction; however, MA tended to be overcorrected. The difference in JLCA between the supine and standing radiographs was the most important preoperative factor that predicted the coronal correction discrepancy after MOWHTO. In patients with larger ΔJLCA, each degree of ΔJLCA should be subtracted from the planned amount of correction angle when preoperative planning is performed using standing radiographs., Level of Evidence: IV.

Introduction: The surgical correction of craniostenosis in children is a time-consuming and taxing procedure. To facilitate this procedure, especially in infants with complex craniostenosis, we refined the computer-aided design and manufacturing technique (CAD/CAM) based on computed tomography (CT)-generated DICOM data. We used cutting guides and molding templates, which allowed the surgeon to reshape and fixate the supraorbital bar extracorporeally on a side table and to control the intracorporal fit without removing the template., Method and Patients: To compare our traditional concept with the possibility of preoperative virtual planning (PVP) technique, the surgical treatment and courses of 16 infants with complex craniostenosis following fronto-orbital advancement (FOA) (age range 8-15 months) were analyzed in two groups (group 1: traditional, control group n = 8, group 2: CAD/CAM planned, n = 8)., Results: While in both groups, the head accurately reshaped postoperatively during the follow-up; the CAD group 2 showed a significantly shorter operating time with a mean of 4 h 25 min compared with group 1 with a mean of 5 h 37 min (p = 0.038). Additionally, the CAD group 2 had a significantly lower volume of blood loss (380 ml vs. 575 ml mean, p = 0.047), lower blood transfusion volume (285 ml vs. 400 ml mean, p = 0.108), lower fresh frozen plasma (FFP) volume (140 ml vs. 275 ml mean, p = 0.019), shorter stay in the pediatric intensive care unit (PICU) (3 vs. 5 days mean (p = 0.002), and shorter total length of hospital stay (6 days vs. 8 days mean, p = 0.002)., Conclusion: CAD/CAM cutting guides and templates offer optimizing operative efficiency, precision, and accuracy in craniostenosis surgery in infants. As shown in this single-center observational study, the use of on-site templates significantly accelerates the reconstruction of the bandeau. The virtual 3D planning technique increases surgical precision without discernible detrimental effects.

Purpose: Evaluation of 3D Dyna-CTs to improve cochlear implantation (CI) planning and intraoperative electrically elicited stapedius reflex threshold (ESRT) measurements., Methods: A prospective observational cohort study was performed. Anonymized data collection of Dyna-CTs and CI surgeries in which a retrofacial approach was implemented to access the stapedius muscle. 3D Dyna-CTs of 30 patients and the intraoperative confirmation of the predication in 5/30 patients during CI surgery were evaluated. Inter-rater reliability was also analyzed along with the predictive value of this evaluation., Results: 36 representative structures of the middle and inner ear and 3D renderings of the Dyna-CTs were evaluated by four otoneurological surgeons. Fleiss' kappa values for the evaluation of the visibility were high (> 0.7) for most of the anatomical structures. The stapedius muscle was visible in 90% of the cases. Using the 3D data, the retrofacial access to the stapedius muscles was estimated as feasible in 86.7%. Fleiss' kappa value of the evaluation of the accessibility was 0.942. The intraoperative exploration of the stapedius muscle confirmed the preoperative prediction in all five selected patients (four patients with predicted accessibility and one patient with predicted inaccessibility)., Conclusions: The use of Dyna-CT and 3D rendering is a helpful tool for preoperative planning of cochlear implantations and ESRT measurements from the stapedius muscle via the retrofacial approach.

Objectives: To evaluate the effect of intensified treatment parameters on safety, functional outcomes, and PSA after MR-Guided Transurethral Ultrasound Ablation (TULSA) of prostatic tissue., Patients and Methods: Baseline and 6-month follow-up data were collected for a single-center cohort of the multicenter Phase I (n = 14/30 at 3 sites) and Pivotal (n = 15/115 at 13 sites) trials of TULSA in men with localized prostate cancer. The Pivotal study used intensified treatment parameters (increased temperature and spatial extent of ablation coverage). The reporting site recruited the most patients to both trials, minimizing the influence of physician experience on this comparison of adverse events, urinary symptoms, continence, and erectile function between subgroups of both studies., Results: For Phase I and TACT patients, median age was 71.0 and 67.0 years, prostate volume 41.0 and 44.5 ml, and PSA 6.7 and 6.7 ng/ml, respectively. All 14 Phase I patients had low-risk prostate cancer, whereas 7 of 15 TACT patients had intermediate-risk disease. Baseline IIEF, IPSS, quality of life, and pad use were similar between groups. Pad use at 1 month and quality of life at 3 months favored Phase I patients. At 6 months, there were no significant differences in functional outcomes or adverse events., Conclusion: TULSA demonstrated acceptable clinical safety in Phase I trial. Intensified treatment parameters in the TACT Pivotal trial increased ablation coverage from 90 to 98% of the prostate without affecting 6-month adverse events or functional outcomes. Long-term follow-up and 12-month biopsies are needed to evaluate oncological safety.

The robotic surgical system was designed to overcome the drawbacks of conventional endoscopic surgery. Since national health insurance in Japan began covering robotic-assisted thoracoscopic surgery (RATS) for malignant lung and mediastinal tumors in 2018, the number of RATS procedures being performed domestically has increased rapidly. This review evaluates the advantages and disadvantages of RATS for patients with lung cancers, based on an electronic literature search of PubMed. The main advantages of RATS are its ability to achieve excellent lymph-node removal with low morbidity and mortality, and minimal postoperative pain. Conversely, its disadvantages include a long operation time and the need for specialized instruments. However, the learning curve for RATS is reported to be shorter than that for VATS: some studies recommend that a surgeon needs to perform 18-22 robotic operations to attain sufficient skill. RATS for lung cancer is more expensive than VATS and the cost of training is high. Although the main disadvantage of RATS is that it reduces operator's tactile senses, the endoscope, which is directly manipulated by the surgeon at the console, using various magnifications, and 3D HD images on the monitor, may compensate for this. Ultimately, RATS offers better maneuverability, accuracy, and stability over VATS.

Purpose: Well planned re-surgery is critical for recurrent/persistent thyroid cancer (TC). We aimed to investigate the clinical outcome of radioguided-occult lesion localization (ROLL) guided surgery in patients with recurrent/persistent TC., Methods: This study includes 29 patients [F/M: 22/7, median age 43 ± 12 years (18-58)] with a diagnosis of TC (22 papillary, 2 follicular and 5 medullary). Before surgery, all patients underwent ultrasonography (USG) guided mapping and intra-lesional radioactivity injection. Surgery was performed based on the excision of radioactivity injected lesions by a gamma probe and non-injected tumor foci via USG-neck map. Researchers determined surgical success by post-operative tumor markers and neck-USG., Results: Among 29 patients, 60 metastatic lesions were identified by USG [median size 10 ± 6.3 mm (range 5-30)]. Neck-USG performed after surgery provided no evidence of disease (NED) in %97 (28/29) of TC patients. In the follow-up, stimulated thyroglobulin (Tg) levels were less than 1 ng/ml in 79%(19/24) of DTC patients and suppressed Tg < 0.2 ng/ml was noted in 92% (22/24).In patients with DTC with an incomplete structural response, we dramatically changed the American Thyroid Association (ATA) response category and achieved an excellent response in 92% (22/24) of patients. Among patients with MTC, 5/5 patients had normal USG and calcitonin levels were reduced by 60-80% in 4/5 and > 80% in1/5 patients., Conclusions: In this study we have shown that, ROLL-guided surgery yielded NED rate of %97 (28/29) and increased excellent response rates according to ATA guidelines. Further studies with larger patient groups and longer follow-up should be performed to confirm the efficacy of this surgery.

Purpose: Accurate puncture of the renal collecting system is crucial to the success of percutaneous nephrolithotomy and presents a technical challenge for urologists. Here, we introduced the Surgical Approach Visualization and Navigation (SAVN) system, a novel navigation system to assist puncture and reduce intraoperative radiation., Materials and Methods: Twenty kidneys of 10 cadavers were randomly divided into two groups for renal calyx puncture. In the control group, traditional fluoroscopy was used for guidance, while SAVN system was used in the experimental group. Puncture duration, number of puncture attempts, total number of intraoperative fluoroscopies, and number of fluoroscopies during the puncture procedure were recorded., Results: The puncture duration was 14.2 ± 2.5 s in SAVN group and 48.3 ± 7.1 s in conventional group (P < 0.05). One puncture attempt was needed for successful puncture in SAVN group, while more than one in conventional group (P = 0.28). The total number of intraoperative fluoroscopies was 3.3 ± 1.0 in SAVN group and 14.5 ± 3.1 in control group (P < 0.05),while the number of fluoroscopies during the puncture procedure was 0 and 11.2 ± 2.4, respectively (P < 0.05)., Conclusions: The novel SAVN system has a simplified structure and is easy to use. It can be used to successfully assist with puncture of the renal calyx, thus reducing puncture duration and radiation dose.

Purpose: To evaluate the efficacy and safety of ultrasound-guided (UG) versus fluoroscopy-guided (FG) percutaneous nephrolithotomy (PCNL)., Methods: A systematic search of PubMed (MEDLINE), Embase, and the Cochrane Library was conducted to identify randomized controlled trials that compared UG-PCNL with FG-PCNL, and a meta-analysis of those studies was completed. The primary outcomes assessed were stone-free rate (SFR) and complication rate. Secondary outcomes assessed were the successful access-creation rate, time necessary for entrance into the target calyx, auxiliary procedure rate, transfusion rate, hemoglobin decrease after surgery, surgery duration, and hospital stay., Results: Eight studies comprising 966 patients were included in the meta-analysis. Compared with FG-PCNL, UG-PCNL had comparable stone-free rates [odds ratio (OR) 0.95; 95% confidence interval (CI) 0.67-1.35; p = 0.79] irrespective of the patient's position, and a favorable safety profile resulting in a lower complication rate (OR 0.56; 95% CI 0.36-0.86; p = 0.009). No statistical difference was found between UG and FG groups in secondary outcomes., Conclusions: UG-PCNL is as effective as FG-PCNL and has the advantage of lower complication rates. In addition, UG-PCNL could be performed with patients in the supine position without compromising its efficacy.

Purpose: To present the safety and efficacy of totally ultrasonography-guided Super-mini percutaneous nephrolithotomy (SMP) in the treatment of upper urinary tract stones both in children and adults., Patients and Methods: We carried out SMP in 104 patients (including 48 children and 56 adults) with upper urinary tract stones between June 2015 and February 2017. All steps of renal access were performed by ultrasonography. The lithotripsy was performed using either Holmium laser or pneumatic lithotripter. Perioperative and postoperative parameters along with operative data were recorded in detail., Results: The mean age of children and adult patients were 4.4 ± 3.6 and 44.3 ± 15.7 years old, respectively. The stone burden was comparable for both groups (1.72 ± 0.66 vs 1.74 ± 0.56 cm, p = 0.852). Mean operation time was not significant different between two groups (p = 0.052), while the mean haemoglobin drop in children was much lower in adult patients (6.3 ± 6.9 vs 10.9 ± 8.69, p = 0.004). Both groups had similar SFRs in postoperative 1 day and at 1-month follow-up (p = 1.000, p = 0.912). Mean hospital stay of children and adult patients was 2.3 ± 0.8 and 2.2 ± 0.76 days (p = 0.484). The total complication rate was significantly lower in two groups (p = 1.000); none of the patients required blood transfusion., Conclusions: Ultrasonography-guided SMP was a safe and effective treatment option for moderate-sized upper urinary tract stones, and has the advantage of preventing radiation hazard, especially for pediatric stone patients.

Purpose: The influence of different implantation techniques in TKA on tibiofemoral kinematics was analysed in few investigations so far. However, the influence on patellar kinematics remain unclear. The aim of the present investigation was to compare patellar kinematics of the natural knee with those of knees after both kinematically and mechanically aligned TKAs., Methods: Patellar kinematics of ten cadaveric knees before and after TKAs implanted using both a kinematic and mechanic alignment technique were investigated and compared using a commercial optical computer navigation system., Results: There was a statistically significant difference between natural patellar kinematics and both implantation techniques analysing mediolateral shift. Patellar lateral tilt showed significant better results in the kinematically compared to the mechanically aligned TKAs. In terms of patella rotation, the patella of both mechanically and kinematically aligned TKAs showed significant higher values for external rotation compared to the natural knee. Regarding epicondylar distance again a significant better restoration of natural kinematics could be found in the kinematically aligned TKAs., Conclusion: Kinematically aligned TKAs showed a better overall restoration of patellar kinematics compared to a conventional mechanical alignment technique. In terms of clinical usefulness, the present study highlights the potential benefit for clinical outcome using a kinematically aligned implantation technique in TKA to achieve a better restoration of natural patellofemoral kinematics.

Purpose: With the increasing use of new minimally invasive approaches in temporal bone surgery, the need arises for evaluation of the risk of injury to sensitive anatomical structures. The factors that influence the measurement uncertainty (variation in representation of position and shape of anatomical structures) of imaging are of relevance. We investigate the effect of patients' anatomy on the measurement uncertainty of medical CT., Methods: Six formalin-fixed temporal bones were used, fiducial markers were bone-implanted, and 20 CT scans of each temporal bone were generated. Surgically threatened anatomical structures of importance were defined. Manual segmentation was performed to create 3D surface models, and different Gaussian filters were applied. Analysis points were established along the border of the superior semicircular canal to determine the deviation between the 3D images of the labyrinth. The standard uncertainty was calculated, and one-way analysis of variance was performed (significance level = 5%) to evaluate the effect of certain factors (patient, side, Gaussian filter) on the measurement uncertainty., Results: The influence of patient-specific anatomy on the measurement uncertainty of medical CT (p = 0.049) was demonstrated for the first time. The applied Gaussian filter (p = 0.622) and the patient's side (p = 0.341) showed no significant effect., Conclusion: The applied method and the results of the statistical analysis suggest that the patient's individual anatomical conditions affect the measurement uncertainty of medical CT. Thus, the patient's anatomy must be considered as an important influencing factor during risk evaluation concerning minimally invasive and image-guided surgery.

Objective: The objective of this study was to evaluate the clinical outcomes of conventional two-dimensional (2D) endoscope with a novel computer-based three-dimensional (3D) imaging system for otologic surgical procedures., Methods: A conventional 2D monocular endoscope with a novel computer-based 3D imaging system was applied to 18 otologic surgical procedures, including chronic otitis media (COM), cholesteatoma, otosclerosis, external canal osteoma and cochlear implant. Operation duration and complications of COM and attic cholesteatoma were recorded to compare 2D and 3D endoscopic ear surgery. Questionnaires were completed by 35 observers participating in the procedures and were used to evaluate clinical and potential side effects., Results: The surgical procedures were performed smoothly for all patients. No patient required switching to conventional 2D endoscopic surgery. No significant differences were apparent in operation duration using the 3D imaging system for chronic otitis media and attic cholesteatoma compared with conventional 2D endoscopic ear surgery. Thirty-five observers completed the questionnaires. Most of them agreed that this 3D imaging system enabled them to perceive stereoscopic vision (94%), provide superior depth perception (85%). Furthermore, 97.1% reported no visual fatigue or discomfort when observing the 3D images., Conclusion: Our study demonstrated that the computer-based 3D imaging system enables the application of 3D vision technology to otologic surgery. The system has no obvious side effects, such as visual fatigue or time delay. It not only facilitates performing the related surgical procedures but also helps in teaching and learning endoscopic ear surgeries.

Purpose: The purpose of this study was to evaluate the differences in flexion space balance when the femoral component is implanted parallel to the surgical transepicondylar axis (TEA) or with 3° of external rotation from the posterior condylar line (PoCoLi). It was hypothesized that implantation parallel to the TEA will produce a more reliably balanced flexion space., Methods: Forty-eight consecutive patients with a varus deformity were prospectively randomized to undergo total knee arthroplasty with a femoral component implanted parallel the TEA, or with 3° of external rotation from the PoCoLi. The posterior condylar angle (PCA) was measured. Intraoperative load measurements were taken at 10°, 45°, and 90° of flexion., Results: The PCA was similar between groups (TEA group: 4.2° ± 1.5° and PoCoLi group: 4.0° ± 1.3°; n.s.). The mean difference in load values between the medial and lateral compartments was significantly lower in the TEA group than in the PoCoLi group at the 45 (0 ± 8 vs. 9 ± 13 lbs; respectively, p = 0.008) and 90° flexion angles (1 ± 9 vs. 10 ± 15 lbs; respectively, p = 0.01). The PoCoLi group had a linear increase in the difference of load values between the medial and lateral compartments with increasing magnitude of the posterior condylar angle (45°, p = 0.0013; 90°, p = 0.0006), but this was not observed in the TEA group., Conclusion: Femoral component implantation parallel to the TEA resulted in a more balanced flexion gap as compared to implantation at 3° of external rotation from the PoCoLi. The intraoperative use of the TEA rather than the PoCoLi to set femoral component rotation may provide a more balanced flexion space and decrease the need for extensive soft tissue releases., Level of Evidence: II.

Purpose: The aim of this study was to compare the intraoperative kinematics of medial and lateral unicompartmental knee arthroplasty (UKA) with those of the native knee using a navigation system., Methods: Six fresh-frozen cadaveric knees were included in the study. Medial UKA was performed in all right knees and lateral UKA was performed in all left knees. All UKA procedures were performed with a computerised navigation system. The tibial internal rotation angle and coronal alignment of the mechanical axis during passive knee flexion were assessed as rotational and varus/valgus kinematics before and after surgery using the navigation system., Results: The rotation angles of the tibia in the early flexion phase of medial UKA were significantly larger than those of native knees (p = 0.008 at minimum knee flexion, p = 0.008 at 0° knee flexion). The rotational kinematics of lateral UKA was similar to those of the native knees throughout knee flexion. There were no significant differences in varus/valgus kinematics between native and UKA knees., Conclusion: The rotational kinematics of the native knee was not restored after medial UKA but was preserved after lateral UKA. There were no significant differences in the varus/valgus kinematics after either medial or lateral UKA when compared with those of the native knees. Thus, the geometry of the medial tibial articular surface is a determinant of the ability to restore the rotational kinematics of the native knee. Surgeons and implant designers should be aware that the anatomical medial articular geometry is an important factor in restoration of the native knee kinematics after knee arthroplasty.

Purpose: Patient-specific instrumentation (PSI) for unicompartmental knee arthroplasty (UKA) has been available for a few years. However, limited literature is available on this subject. Hence, the aim of this cohort study is to evaluate the 2 years' results of our first experiences with the use of PSI in UKA. It is hypothesised that there is no advantage in rate of adverse events and in radiological and functional outcomes in comparison to literature on the conventional method., Methods: This cohort included 129 knees of 122 patients, operated by one surgeon. Outcome measures were the rate of adverse events (AEs); implant position as determined on radiographs; the accuracy of the default and approved planning of the implant sizes and the patient-reported outcome measures (PROMs) preoperatively, and at 3, 12 and 24 months, postoperatively., Results: A total of 6 (4.9%) AEs were observed in this study, with 4 (3.3%) tibial fractures being the main complication. The mean postoperative biomechanical axis was 176.4° and in the majority of cases, the radiographic criteria, as determined by the manufacturer, were met. The tibial component showed 20 (16.4%) outliers in the sagittal and 3 (2.5%) outliers in the frontal plane. There were no outliers of the femoral component. For the femoral and tibial components, respectively, in 125 (96.9%) and 79 (61.7%) cases, there was an agreement between approved planning and implanted component size. All PROMs improved significantly after surgery., Conclusion: Tibial fracture was the most common AE, probably related to the transition from cemented to uncemented UKA. Perioperative modifications to the surgical technique were made in order to prevent this AE. Improvements should be made to the operation technique of the uncemented tibial plateau to obtain an adequate placement and at the same time reduce the risk for tibial fracture. The PSI technique was a reliable tool for the placement of the femoral component. Functional outcome was in line with literature on the conventional method. It is strongly recommended that the surgeon approves every preoperative plan, in order to optimise the accuracy during the PSI surgery., Level of Evidence: III.

Purpose: The benefits of simultaneous bilateral total knee arthroplasty (SBTKR) include reduced hospital costs, single anaesthetic exposure and in many cases is also the patient's preference. Despite these potential benefits, risk-adversity with respect to assumed complications and mortality make it difficult for the orthopaedic surgeon and patient to make an informed decision. This study aimed to address the inconsistencies and lack of consensus in previous literature regarding the short-term complications and clinical safety of SBTKR in patients with end-stage knee osteoarthritis (OA)., Methods: A cohort of 950 knees (475 patients) undergoing surgery between 2008 and 2013 was extracted from a prospectively collected clinical database and retrospectively linked to the Australian Joint Replacement Registry and hospital records. Patients underwent sequential SBTKR by their treating surgeon under one anaesthetic. Basic demographic data and outcome data including complications and mortality were collected. All data were analyzed using descriptive statistics only., Results: A total of 413 patients and 826 knees were included. The average age of the cohort was 70 years with range between 46 and 88 years. 50% of patients were female. The overall mortality rate during the study follow-up period was 1.9%, with an average time to death postoperatively of 23.8 months. There were no cases of acute postoperative mortality (< 6 weeks). Medical complication rates were low., Conclusions: In contrast to the higher mortality and complication rates suggested in previous literature, this study has demonstrated that SBTKR is safe, with low mortality and complication rates under the current surgical protocol., Level of Evidence: IV.

Purpose: Patient-specific instruments (PSIs) are already in relatively common use, and their post-operative radiographic results are equal to those for total knee arthroplasty (TKA) with conventional instrumentation. PSI use requires a preoperative MRI scan, CT scan, or a combination of MRI and a long-leg standing radiograph. However, there is no consensus as to which of these modalities, MRI or CT, is the preferred imaging modality when performing TKA with PSIs., Methods: This systematic literature review and meta-analysis studied the differences in alignment outliers between CT- and MRI-based PSI for TKA. A search of the Cochrane Database of Systematic Reviews, MEDLINE/PubMed and Embase was conducted, without restriction on date of publication. Only level I evidence studies written in English that included TKA with the use of MRI- and CT-based PSI were selected. A meta-analysis was then performed of the rate of outliers in the biomechanical axis and individual femoral and tibial component alignment. Where considerable heterogeneity among studies was present or the data did not provide sufficient information for performing the meta-analysis, a qualitative synthesis was undertaken., Results: Twelve randomized controlled trials, studying 841 knees, were eligible for data extraction and meta-analysis. MRI-based PSI resulted in a significantly lower proportion of coronal plane outliers with regard to the lateral femoral component (OR 0.52, 95% CI 0.30-0.89, P = 0.02), without significant heterogeneity (n.s.). There were no significant differences regarding the biomechanical axis or frontal femoral and individual tibial component alignment., Conclusion: This systematic review and meta-analysis demonstrate that alignment with MRI-based PSI is at least as good as, if not better than, that with CT-based PSI. To prevent for malalignment, MRI should be the imaging modality of choice when performing TKA surgery with PSI., Level of Evidence: I.

Purpose: Managing focal cartilage injuries in the middle-aged patient poses a challenge. Focal prosthetic inlay resurfacing has been proposed to be a bridge between biologics and conventional joint arthroplasty. Patient selection and accurate implant positioning is crucial to avoid increased contact pressure to the opposite cartilage surface. A customized femoral condyle implant for focal cartilage injuries was designed to precisely fit each patient's individual size and location of damage. The primary objective was to assess implant safety profile, surgical usability of the implant and instruments, and implant migration with radiostereometric analysis (RSA)., Methods: Ten patients 36-56 years with focal chondral defects, ICRS 3-4 of the femoral cartilage and failed earlier conservative or surgical interventions with VAS pain > 40. The patients were followed for 2 years with subjective outcome measures (VAS, EQ5D, KOOS) and RSA. The customized implant and guide instruments were manufactured by computer-aided design/computer-aided manufacturing (CAD/CAM) techniques using MRI data., Results: VAS, EQ5D and KOOS showed improvements that reached significance for VAS (p ≤ 0.001), Tegner (p = 0.034) and the KOOS subscores ADL (p = 0.0048), sport and recreation (p = 0.034) and quality of life (p = 0.037). VAS and KOOS scores improved gradually at 3, 6 and 12 months. The improvements in EQ5D, KOOS pain and KOOS symptoms did not reach statistical significance. No infections, deep venous thrombosis or other complications occured in the postoperative period. No radiographic signs of damage to the opposing tibial cartilage was noted. The surgical usability of implants and instruments were good. RSA did not show any implant migration., Conclusion: This is the first clinical report of a new customized, focal knee resurfacing system. The short-term implant safety and patient-related outcome measures showed good-to-excellent results., Level of Evidence: Prospective case series, Level 4.

Purpose: The primary aim of the study was to examine stability and alignment after total knee arthroplasty (TKA) using patient-specific instrumentation (PSI) and conventional instrumentation (CI). The hypothesis was that stability and alignment would be better using PSI than CI, 12 months postoperatively. The secondary aim included the evaluation of clinical outcomes after TKA., Methods: In this prospective randomized controlled trial, 42 patients with knee osteoarthritis received a Genesis II PS prosthesis with either PSI or CI. Patients visited the hospital preoperatively and postoperatively after 6 weeks and 3 and 12 months. To evaluate stability, varus-valgus laxity was determined in extension and flexion using stress radiographs 12 months postoperatively. Three months postoperatively, a long-leg radiograph and CT scan were obtained to measure hip-knee-ankle (HKA) alignment and component rotation. Furthermore, frontal and sagittal alignment of the components, the Knee Society Score, VAS Pain, VAS Satisfaction, Knee injury and Osteoarthritis Outcome score, Patella score (Kujala), University of California Los Angeles activity score, anterior-posterior laxity, (serious) adverse device-related events, and intraoperative complications were reported. The clinical outcomes were compared using independent t tests or non-parametric alternatives, and repeated measurements ANOVA with a significance level of p < 0.05., Results: No significant differences were found between the two groups regarding stability, HKA angle, and rotational alignment. In four patients, the PSI did not fit correctly on the tibia and/or femur requiring intraoperative modifications. Both groups improved significantly over time on all clinical outcomes, with no significant differences between the groups 12 months postoperatively. The PSI group showed less tibial slope than the patients in the CI group [PSI 2.6° versus CI 4.8° (p = 0.02)]. Finally, the PSI group more frequently received a thinner insert size than the CI group (p = 0.03)., Conclusions: Patients operated with PSI did not differ from CI in terms of stability and alignment. However, in the PSI group ligament releases were more often required intraoperatively. Furthermore, the two methods did not show different clinical results. It seems that the preoperative planning for the PSI facilitates more conservative bone cuts than CI, but whether this is clinically relevant should be investigated. Since PSI is more expensive and time consuming than CI, and does not outperform CI with regard to clinical results, we recommend to use CI., Level of Evidence: I.

Purpose: Malalignment of implants is a major source of failure during total knee arthroplasty. To achieve more accurate 3D planning and execution of the osteotomy cuts during surgery, the Signature (Biomet, Warsaw) patient-specific instrumentation (PSI) was used to produce pin guides for the positioning of the osteotomy blocks by means of computer-aided manufacture based on CT scan images. The research question of this study is: what is the transfer accuracy of osteotomy planes predicted by the Signature PSI system for preoperative 3D planning and intraoperative block-guided pin placement to perform total knee arthroplasty procedures?, Methods: The transfer accuracy achieved by using the Signature PSI system was evaluated by comparing the osteotomy planes predicted preoperatively with the osteotomy planes seen intraoperatively in human cadaveric legs. Outcomes were measured in terms of translational and rotational errors (varus, valgus, flexion, extension and axial rotation) for both tibia and femur osteotomies., Results: Average translational errors between the osteotomy planes predicted using the Signature system and the actual osteotomy planes achieved was 0.8 mm (± 0.5 mm) for the tibia and 0.7 mm (± 4.0 mm) for the femur. Average rotational errors in relation to predicted and achieved osteotomy planes were 0.1° (± 1.2°) of varus and 0.4° (± 1.7°) of anterior slope (extension) for the tibia, and 2.8° (± 2.0°) of varus and 0.9° (± 2.7°) of flexion and 1.4° (± 2.2°) of external rotation for the femur., Conclusion: The similarity between osteotomy planes predicted using the Signature system and osteotomy planes actually achieved was excellent for the tibia although some discrepancies were seen for the femur. The use of 3D system techniques in TKA surgery can provide accurate intraoperative guidance, especially for patients with deformed bone, tailored to individual patients and ensure better placement of the implant.

Purpose: Patient-specific instrumentation (PSI) has been proposed as a means of improving surgical accuracy and ease of implantation during technically challenging procedures such as unicompartmental knee arthroplasty (UKA). The purpose of this prospective randomised controlled trial was to compare the accuracy of implantation and functional outcome of mobile-bearing medial UKAs implanted with and without PSI by experienced UKA surgeons., Methods: Mobile-bearing medial UKAs were implanted in 43 patients using either PSI guides or conventional instrumentation. Intra-operative measurements, meniscal bearing size implanted, and post-operative radiographic analyses were performed to assess component positioning. Functional outcome was determined using the Oxford Knee Score (OKS)., Results: PSI guides could not be used in three cases due to concerns regarding accuracy and registration onto native anatomy, particularly on the tibial side. In general, similar component alignment and positioning was achieved using the two systems (n.s. for coronal/sagittal alignment and tibial coverage). The PSI group had greater tibial slope (p = 0.029). The control group had a higher number of optimum size meniscal bearing inserted (95 vs 52%; p = 0.001). There were no differences in OKS improvements (n.s)., Conclusion: Component positioning for the two groups was similar for the femur but less accurate on the tibial side using PSI, often with some unnecessarily deep resections of the tibial plateau. Although PSI was comparable to conventional instrumentation based on OKS improvements at 12 months, we continue to use conventional instrumentation for UKA at our institution until further improvements to the PSI guides can be demonstrated., Level of Evidence: Therapeutic, Level I.

Purpose: Patient-specific instruments (PSI) were initially developed for the alignment of both total knee- (TKA) and partial knee arthroplasty (PKA). We hypothesize that CT-based PSI for PKA-to-TKA revision surgery can restore biomechanical limb alignment and prosthetic component positioning in vivo as calculated pre-operatively, resulting in a limited percentages of outliers., Methods: An imaging analysis was performed using CT-based 3D measurement methods based on a pre- and post-revision CT scan. Imaging data were gathered on 10 patients who were operated for PKA-to-TKA revision with the use of PSI based on CT imaging. The planned femur and tibia component position in vivo were compared with the pre-revision planned component position. Outliers were defined as deviations >3.0° from pre-revision planned position for the individual implant components. Adjustments (e.g. resection level and implant size) during surgery were recorded., Results: The HKA axis was restored accurately in all patients with a mean post-operative HKA axis of 178.1° (1.4°). Five femoral (2 varus, 2 internal rotation and 1 extension) and 14 tibial guides (2 varus, 6 anterior slope, 3 internal rotation and 3 external rotation) on a total of 60 outcome measures were identified as outliers. During surgery, an intraoperative tibial resection of 2 mm extra was performed in three patients. In 80 and 70% for, respectively, the femur and tibia, the surgeon-planned size was implanted during surgery. All patient-specific guides fitted well in all patients. No intraoperative or post-operative complications related to surgery were registered., Conclusions: This study introduced a unique new concept regarding PSI, PKA-to-TKA revision surgery. Based on the results, we were unable to fully confirm our hypothesis. PSI as a "new" tool for PKA-to-TKA revision surgery appears to be an accurate tool for the alignment of the TKA femur component. The tibial guide seems more susceptible to errors, resulting in a substantial percentage of outliers., Level of Evidence: Prospective cohort study, Level II.

Objective: To analyze the effectiveness of the multiplanar analysis of the retromandibular vein in establishing the position of the parotid gland tumor and its relationship with the facial nerve, together with the most common radiological criteria (facial nerve line, Utrecht line, retromandibular vein and parapharyngeal space variations) using the magnetic resonance imaging., Study Design: Retrospective study SETTING: Tertiary Academic Hospital SUBJECTS AND METHODS: 128 preoperative magnetic resonances were analyzed to study preoperative tumor location (medial or lateral to the expected course of the facial nerve) based on comparison between the radiological criteria and the surgical findings., Results: FN line had the lowest accuracy at 77%, whereas the retromandibular vein achieved 85% accuracy and the UT line achieved accuracy of 93%. The retromandibular vein could not be identified in 11 cases (9%). The multiplanar evaluation of the retromandibular vein allowed us to identify it on almost all MR images (99% of cases) and reach 87% of accuracy. The parapharyngeal space evaluation achieved 92% of accuracy. In the subgroup of 66 cases where the neoplasms were strictly related to the main trunk, where the surgery entailed manipulation if situated laterally to the tumor, the multiplanar evaluation of the retromandibular vein reached 98% of accuracy and UT line achieved 94%., Conclusions: The multiplanar modality, combined with the evaluation of the parapharyngeal space, is effective in helping the surgeon to achieve accurate planning: it enables the tumor to be located and the facial nerve course predicted with a good precision.

Introduction: Sagittal synostosis affects 1 in 1000 live births and may result in increased intracranial pressure, hindrance of normal neural development, and cosmetic deformity due to scaphocephaly. Historically, several approaches have been utilized for surgical correction and recently, computed tomography (CT)-guided reconstruction procedures are increasingly used. In this report, the authors describe the use of a CT-derived virtual and stereolithographic (3D printed) craniofacial models, which are used to guide intraoperative bone placement, and intraoperative CT guidance for confirmation of bone placement, to ensure the accuracy of surgical correction of scaphocephaly, as demonstrated to parents., Methods: Preoperative high-resolution CT imaging was used to construct 3D image sets of the skulls of two infants (a 14-month-old female and a 6-month-old male) with scaphocephaly. These 3D image sets were then used to create a virtual model of the proposed surgical correction for each of the infants' deformities, which was then printed and made available for use intraoperatively to plan the bone flap, fashion the bone cuts, and optimize graft placement. After the remodeling, adherence to the preoperative plan was assessed by overlaying a CT scan of the remodeled skull with the virtual model. Deviations from the preoperative model were noted., Results: Both patients had excellent postoperative cosmetic correction of head shape and contouring. The mean operative time was 5 h, blood loss was 100 ml, and one child required modification of the subocciput after intraoperative imaging showed a deviation of the reconstruction from the surgical goal as depicted by the preoperative model., Conclusion: The addition of neuro-navigation to stereolithographic modeling ensured the accuracy of the reconstruction for our patients and provided greater confidence to both surgeons and parents. While unisutural cases are presented for clarity, correction was still required for one patient. The cost of the models and the additional CT required must be weighed against the complexity of the procedure and possibly reserved for patients with potentially complicated corrections.

Purpose: The aim of this study was to determine factors that contribute to bone cutting errors of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by an image-free navigation system. The hypothesis is that preoperative varus alignment is a significant contributory factor to tibial bone cutting errors., Methods: This was a prospective study of a consecutive series of 72 TKAs. The amount of the tibial first-cut errors with reference to the planned cutting plane in both coronal and sagittal planes was measured by an image-free computer navigation system. Multiple regression models were developed with the amount of tibial cutting error in the coronal and sagittal planes as dependent variables and sex, age, disease, height, body mass index, preoperative alignment, patellar height (Insall-Salvati ratio) and preoperative flexion angle as independent variables., Results: Multiple regression analysis showed that sex (male gender) (R = 0.25 p = 0.047) and preoperative varus alignment (R = 0.42, p = 0.001) were positively associated with varus tibial cutting errors in the coronal plane. In the sagittal plane, none of the independent variables was significant., Conclusion: When performing TKA in varus deformity, careful confirmation of the bone cutting surface should be performed to avoid varus alignment. The results of this study suggest technical considerations that can help a surgeon achieve more accurate component placement., Level of Evidence: IV.