• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.198-207
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• 2012

This paper presents an overview of automated robotic system for skull drilling, which is performed to access for some neurosurgical interventions, such as brain tumor resection. Currently surgeons use automatic-releasing cranial perforators. The drilling procedure must be performed very carefully to avoid penetration of brain nerve structures; however failure cases are reported. The presented prototype system utilizes both preoperative and intraoperative information. Preoperative CT image is used for robot path planning. A NeuroMate robot with a six-DOF force sensor at the end effector is used for intraoperative operation. Intraoperative cutting force from the force sensor is the key information to revise an initial registration and preoperative path plans. Some possibilities are verified by path simulation but cadaver experiments are required for validation of this prototype.

• The korean journal of orthodontics
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• v.51 no.5
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• pp.321-328
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• 2021

Objective: To examine the accuracy of computer-aided intraoperative navigation (Ci-Navi) in bimaxillary orthognathic surgery by comparing preoperative planning and postoperative outcome. Methods: The study comprised 45 patients with congenital dentomaxillofacial deformities who were scheduled to undergo bimaxillary orthognathic surgery. Virtual bimaxillary orthognathic surgery was simulated using Mimics software. Intraoperatively, a Le Fort I osteotomy of the maxilla was performed using osteotomy guide plates. After the Le Fort I osteotomy and bilateral sagittal split ramus osteotomy of the mandible, the mobilized maxilla and the distal mandibular segment were fixed using an occlusal splint, forming the maxillomandibular complex (MMC). Real-time Ci-Navi was used to lead the MMC in the designated direction. Osteoplasty of the inferior border of the mandible was performed using Ci-Navi when facial symmetry and skeletal harmony were of concern. Linear and angular distinctions between preoperative planning and postoperative outcomes were calculated. Results: The mean linear difference was 0.79 mm (maxilla: 0.62 mm, mandible: 0.88 mm) and the overall mean angular difference was 1.20°. The observed difference in the upper incisor point to the Frankfort horizontal plane, midfacial sagittal plane, and coronal plane was < 1 mm in 40 cases. Conclusions: This study demonstrates the role of Ci-Navi in the accurate positioning of bone segments during bimaxillary orthognathic surgery. Ci-Navi was found to be a reliable method for the accurate transfer of the surgical plan during an operation.

• The Journal of the Korean dental association
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• v.25 no.9 s.220
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• pp.847-854
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• 1987

Genioplasty may considerably change a person's face which needs surgical correction of deformed chin. Comprehensive treatment planning is therefore decisive for the treatment to be successful. A three-dimensional analysis of chin relative to cranial base, upper and lower jaws using the frontal and lateral facial photographs and cephalographs permits classification of the defective chin position and provides a basis for operation planning and deciding upon the operation method. A chin miniplate system has been developed for intraoperative registration securing the sagittal, vertical and horizontal position of the osteotomized chin and ould reduce the relapse rate.

• Korean Journal of Computational Design and Engineering
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• v.16 no.5
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• pp.331-343
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• 2011

High tibial osteotomy (HTO) is a widely accepted treatment for unicompartmental osteoarthritis of the knee and other lower extremity deformities, particularly for young and active patients. However, it is generally recognized as a technically demanding procedure. Thus the limitations of conventional surgical methods have been reported. Currently, the use of computer-aided surgery (CAS) system for successful surgery was increased. However it has been reported many problems such as expensive equipment, infection or fracture caused by inserting half-pin and delaying surgery. Therefore we propose a novel method which can be tracked by using tracking-pin inserted in arbitrary locations of the femur and tibia, and fluoroscopic images obtained from G-arm of antero-posterior and lateral-medial.

• Archives of Hand and Microsurgery
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• v.22 no.3
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• pp.137-146
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• 2017

Brachial plexus injury is regarded as one of the most devastating injuries of the upper extremity. Accurate diagnosis is important to obtain the successful results. Basic preoperative evaluation includes simple radiography, cervical myelography. Magnetic resonance imaging, angiography, electrophysiologic studies and intraoperative studies. Furthermore, proper timing of surgery, surgical indication, plan and sufficient understanding of patients about the prognosis are the key for the satisfactory outcomes. This article provides an overview of the evaluation, diagnosis, intraoperative monitoring, and proper surgical planning for the treatment of posttraumatic brachial plexus injuries.

• Clinics in Shoulder and Elbow
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• v.26 no.2
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• pp.117-125
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• 2023

Background: Preoperative traditional software planning (TSP) is a method used to assist surgeons with implant selection and glenoid guide-pin insertion in shoulder arthroplasty. Mixed reality (MR) is a new technology that uses digital holograms of the preoperative plan and guide-pin trajectory projected into the operative field. The purpose of this study was to compare TSP to MR in a simulated surgical environment involving insertion of guide-pins into models of severely deformed glenoids. Methods: Eight surgeons inserted guide-pins into eight randomized three-dimensional-printed severely eroded glenoid models in a simulated surgical environment using either TSP or MR. In total, 128 glenoid models were used and statistically compared. The outcomes compared between techniques included procedural time, difference in guide-pin start point, difference in version and inclination, and surgeon confidence via a confidence rating scale. Results: When comparing traditional preoperative software planning to MR visualization as techniques to assist surgeons in glenoid guide pin insertion, there were no statistically significant differences in terms of mean procedure time (P=0.634), glenoid start-point (TSP=2.2±0.2 mm, MR=2.1±0.1 mm; P=0.760), guide-pin orientation (P=0.586), or confidence rating score (P=0.850). Conclusions: The results demonstrate that there were no significant differences between traditional preoperative software planning and MR visualization for guide-pin placement into models of eroded glenoids. A perceived benefit of MR is the real-time intraoperative visibility of the surgical plan and the patient's anatomy; however, this did not translate into decreased procedural time or improved guide-pin position.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.296-299
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• 2006

A 35-year-old woman, previously treated for systemic metastases from retroperitoneal yolk sac tumor, presented with progressive painful paraparesis. Preoperative images showed severe cord compression by the metastatic infiltration of the lumbar vertebrae and epidural mass as well as a huge retroperitoneal mass. While performing unremarkable surgery in prone position, the patient abruptly fell into hypoxic insults and circulatory arrest. Intraoperative pulmonary tumor embolism was deemed a cause of death. When planning operative procedure for this dangerous malignancy, scrupulous manipulation is mandated and the possibility of fatal pulmonary tumor embolism should also be addressed and fully discussed preoperatively.

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.418-425
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• 2023

Objective : Deciphering the anatomy of posterior communicating artery (PCoA) aneurysms in relation to surrounding structures is essential to determine adjuvant surgical procedures. However, it is difficult to predict surgical structures through preoperative imaging studies. We aimed to present anatomical structures using preoperative high-resolution three-dimensional proton density-weighted turbo spin-echo magnetic resonance (PDMR) imaging with simple classification. Methods : From January 2020 to April 2022, 30 patients underwent PDMR before microsurgical clipping for unruptured PCoA aneurysms in a single tertiary institute. We retrospectively reviewed the radiographic images and operative data of these patients. The structural relationship described by PDMR and intraoperative findings were compared. Subsequently, we classified aneurysms into two groups and analyzed the rate of adjuvant surgical procedures and contact with the surrounding structures. Results : Correlations between preoperative PDMR predictions and actual intraoperative findings for PCoA aneurysm contact to the oculomotor nerve, temporal uncus, and anterior petroclinoid fold (APCF) reported a diagnostic accuracy of 0.90, 0.87, and 0.90, respectively. In 12 patients (40.0%), an aneurysm dome was located on the plane of the oculomotor triangle and was classified as the infratentorial type. Compared to the supratentorial type PCoA aneurysm, adjuvant procedures were required more frequently (66.7% vs. 22.2%, p=0.024) for infratentorial type PCoA aneurysm clipping. Conclusion : Preoperative PCoA aneurysm categorization using PDMR can be helpful for predicting surgical complexity and planning of microsurgical clipping.

• Archives of Plastic Surgery
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• v.47 no.4
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• pp.365-370
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• 2020

The ability to directly harvest thin and superthin perforator flaps without jeopardizing their vascularity depends on knowledge of the microsurgical vascular anatomy of each perforator within the subcutaneous tissue up to the dermis. In this paper, we report our experience with ultrahigh-frequency ultrasound (UHF-US) in the preoperative planning of thin and superthin flaps. Between May 2017 and September 2018, perforators of seven patients were preoperatively evaluated by both ultrasound (using an 18-MHz linear probe) and UHF-US (using 48- and 70-MHz linear probes). Thin flaps (two cases) and superthin flaps (five cases) were elevated for the reconstruction of head and neck oncologic defects and lower limb traumatic defects. The mean flap size was 6.5×15 cm (range, 5×8 to 7.5×23 cm). No complications occurred, and all flaps survived completely. In all cases, we found 100% agreement between the preoperative UHF-US results and the intraoperative findings. The final reconstructive outcomes were considered satisfactory by both the surgeon and the patients. In conclusion, UHF-US was found to be very useful in the preoperative planning of thin and superthin free flaps, as it allows precise anticipation of very superficial microvascular anatomy. UHF-US may represent the next frontier in thin, superthin, and pure skin perforator flap design.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.117-124
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• 2021

Although current surgical techniques have reduced the incidence of malunion, it is still observed because of the complexity of the fracture or associated injuries. Osteotomy is needed when the amount of malunion is expected to result in an overload of cartilage and instability of the joint. Preoperative planning is essential when performing an osteotomy for malunion. Inadequate planning can result in serious complications, such as iatrogenic malalignment, intraoperative fracture, postoperative recurrence of deformity, or soft tissue injuries. In addition, a poor functional result can occur secondary to poor patient selection. This review article includes the surgical indications and planning to correct malunion. Various methods of corrective osteotomy are described according to the kinds of plane and fixation implants.