Application of computer-assisted navigation technology in the resection and reconstruction of mandibular ameloblastoma / 口腔医学

Objective@# Using computer-assisted navigation technology to guide the resection and reconstruction of mandibular ameloblastoma, evaluating its treatment effect.@*Methods @# Twelve patients were selected from the Affiliated Stomatological Hospital of Nanjing University from January 2017 to May 2022. All 12 patients accepted same surgery which included resection of mandibular ameloblastoma and reconstruction by fibula musculocutaneous flap. Among them, 6 cases were included in the navigation group; 6 cases were in the non-navigation group. Advantages and disadvantages of computer-assisted navigation technology in this operation were evaluated with these cases. @*Results@# The 12 operations were performed by the same operator. The average time for fixing the navigation bracket and performing navigation in the navigation group was about 15 minutes. Compared with the non-navigation group, the average operation time in the navigation group was shortened by about 10 minutes. In the navigation group, the mandible resection range matched the fibula musculocutaneous flap well, and the occlusal relationship recovered well. @*Conclusion @#Using the mandibular reference frame, under the guidance of computer-assisted navigation technology, the resection and reconstruction of mandibular ameloblastoma can be performed quickly and accurately.

Guidelines for navigation-assisted spine surgery / 医学前沿

Spinal surgery is a technically demanding and challenging procedure because of the complicated anatomical structures of the spine and its proximity to several important tissues. Surgical landmarks and fluoroscopy have been used for pedicle screw insertion but are found to produce inaccuracies in placement. Improving the safety and accuracy of spinal surgery has increasingly become a clinical concern. Computerassisted navigation is an extension and application of precision medicine in orthopaedic surgery and has significantly improved the accuracy of spinal surgery. However, no clinical guidelines have been published for this relatively new and fast-growing technique, thus potentially limiting its adoption. In accordance with the consensus of consultant specialists, literature reviews, and our local experience, these guidelines include the basic concepts of the navigation system, workflow of navigation-assisted spinal surgery, some common pitfalls, and recommended solutions. This work helps to standardize navigation-assisted spinal surgery, improve its clinical efficiency and precision, and shorten the clinical learning curve.

Accuracy Verification of Robot-assisted Mandibular Reconstruction Surgery / 中国医疗器械杂志

Mandible is an important bone of the head and neck. Mandibular defects not only affect patient's face, but also impede patient's daily functions, such as chewing, speech, and so on. Fibular transplantation for mandibular reconstruction is the common method, which requests high accuracy of bone positioning and posture adjustment. Therefore, a robotic system for mandibular reconstruction surgery with fibula flaps was designed to assist surgeons to hold and locate bones, and the model comparison experiments were conducted. The results showed that the robotic system can assist surgeons for mandibular reconstruction to improve quality of surgery.

Clinical analysis of adult spontaneous cerebrospinal fluid rhinorrhea / 临床耳鼻咽喉头颈外科杂志

OBJECTIVES@#To discuss the clinical characteristics, diagnosis and treatment of adult spontaneous cerebrospinal fluid rhinorrhea (CSFR).@*METHODS@#A retrospective study was conducted on 18 patients of CSFR. Nasal secretion was collected for biochemical analysis. Imaging examination was done for identification of the bony defect in skull base.@*RESULTS@#In all cases, the glucose concentration of nasal secretion were more than 1.7 mmol/L, and the β-2 transferrin detected by immunoelectrophoresis technique were positive. Twelve cases were found to have bony defect in skull base. For the rest 6 cases without bony defect, MRI findings of 6 cases showed sinusoidal effusion with similar signals to cerebrospinal fluid, thus predicting the location of the leak. Conservative treatment was successful in one case, and the other 17 patients underwent endoscopic sinus surgery with computer assisted navigation system (CANS). The results of all cases underwent surgery were successful by one time. No recurrence occured during the follow-up time (11 to 24 months).@*CONCLUSIONS@#The incidence of adult CSFR is low, hence it is easily to be missed and misdiagnosed. The majority of CSFR patients are middle-aged and elderly obese women, often combined with hypertension, diabetes, moderate and severe osteoporosis due to no daily exercise habits. Correct medical history collection, reasonable preoperative examination and accurate preoperative localization of bony defect are essential for surgical repairment. CANS used during operation can enable surgeons to locate the site of leakage accurately and shorten the operation time.

Application of a computer-assisted navigation system (CANS) in the treatment of complicated orbital fractures / 中华医学美学美容杂志

Objective To evaluate the effectiveness of computer-assisted navigation system on open reduction as treatment for complicated orbital fractures.Methods The computed tomography (CT) data for 6 patients with complicated orbital fractures were obtained before surgery and imported into the surgical planning software.After 3-dimensional (3D) construction and segmentation,data from the unaffected side were used to guide the reduction data,and surgical simulation was performed.All patients underwent open reduction under the guidance of the navigation system.The segments were then reduced to the predetermined places.CT measurements were used to evaluate navigation accuracy and bone symmetry.Results A fairly accurate match between the intraoperative anatomy and the computed tomography images was achieved through registration,with a systematic error of 1 mm difference.With guidance of the navigation system,open reduction of fractures was performed in all cases.The reduction was checked by postoperative computed tomography scans,with a good match with preoperative planning noted.The maximal deviation between the reduction and preoperative planning was less than 2 mm.The postoperative facial appearance of the patients was clearly improved.Conclusions Navigation-guided open reduction of complicated orbital fractures can be regarded as a valuable treatment option for this potentially complicated procedure.

Computer Assisted Navigation in Knee Arthroplasty

Computer assisted surgery (CAS) was used to improve the positioning of implants during total knee arthroplasty (TKA). Most studies have reported that computer assisted navigation reduced the outliers of alignment and component malpositioning. However, additional sophisticated studies are necessary to determine if the improvement of alignment will improve long-term clinical results and increase the survival rate of the implant. Knowledge of CAS-TKA technology and understanding the advantages and limitations of navigation are crucial to the successful application of the CAS technique in TKA. In this article, we review the components of navigation, classification of the system, surgical method, potential error, clinical results, advantages, and disadvantages.

Navigation-Assisted Total Knee Arthroplasty for the Knee Retaining Femoral Intramedullary Nail, and Distal Femoral Plate and Screws

Proper ligament balancing, restoration of the mechanical axis and component alignment are essential for the success and longevity of a prosthesis. In conventional total knee arthroplasty (TKA), an intramedullary guide is used to improve the alignment. An extramedullary guide can be used in cases of severe femoral bowing or intramedullary nailing but its use is more subjective and relies on the surgeon's experience. This paper reports two successful cases of navigation-assisted TKA for severe right knee osteoarthritis retaining a femoral intrameullary nail, and left knee osteoarthritis retaining a distal femoral plate.

Causative Factors for Femoral Pin Track Fractures in Navigated Total Knee Arthroplasty

This retrospective radiographic analysis of 57 patients (62 knees) examined two possible factors involved in pin tract fractures of the femur due to navigated total knee arthroplasty (TKA): the angle of the tracker pin with respect to the lateral femoral cortex, and the distance between the tracker pin and the lateral joint line. Our findings demonstrate a relationship between postoperative pin tract induced stress fractures (3 patients), with pin tract angles exceeding 15. Pin placement at a site more th

Improved computer-assisted fluoroscopic navigation to guide percutaneous kyphoplasty to treat multiple osteoporotic spinal compression fractures / 中国综合临床

Objective To explore clinlical outcomes of using improved computer-assisted fluoroscopic navi-gation to guide the percutaneous vertebroplasty to treat multiple osteoporotic spinal compression fractures. Methods Twenty-eight multiple osteoporotic spinal compression fractures patients with 73 painful vertebral body were got an-terio posterior,lateral and oblique radiographic imaging by using computer-assisted fluoroscopic navigation to imitate anterior- posterior. Lateral spinal and axial pedicle virtual image was obtained to guide the percutaneous kyphoplas-ty. Results All painful vertebral body were one-sided punctured,all percutaneous kyphoplasties were succeed by guiding with computer-assisted fluoroscopic navigation. Navigation virtual puncture needle image basically matched with reality view. PMMA dosage was 2.5 ～ 4 ml. Postioporational CT showed that the PMMA filled spinal focus very well. 11 cases completely relieved and 17 cases partially relieved. Conclusion Using improved computer-assisted fluoroscopic navigation to guide the PKP to treatment multiple osteoporotic spinal compression fractures decreases op-erative time and radiation injury. It is a safe,precise,minimally invasive method.

Total Knee Arthroplasty Using Computer-Assisted Navigation in Patient with Ipsilateral Hemiarthroplasty and Angle Blade Plate Fixation: A Case Report

A 79-year-old female patient had bipolar hemiarthroplasty because of a nonunion of the intertrochanteric fracture of the right femur seven months ago. As she got hurt from slip down during rehabilitation and supracondylar fracture of the ipsilateral femur occurred, she underwent open reduction and internal fixation with angle blade plate. Her walking and daily living were seriously limited because of degenerative arthritis of the right knee joint. She underwent the total knee arthroplasty using computer-assisted navigation without removal of the hard wares inserted in the femur.

Comparison of Radiologic Measurements of Total Knee Replacement using Computer-assisted Navigation System and Conventional System in Varus Deformity of the Knee / 대한정형외과학회잡지

PURPOSE: To compare the radiologic measurements of the mechanical axis and the implant position of Total Knee Arthroplasty (TKA) using a computer-assisted navigation system with those using conventional TKA in varus deformity. MATERIALS AND METHODS: From January 2004 to January 2005, 49 TKAs using a CT-free navigation system (Vector Vision(R), BrainLab, Heirnstetten, Germany) (Group I) and 24 TKAs using the conventional technique (Group II) were performed on patients who had a preoperative varus deformity>10degrees. The patients were also subdivided into two groups, patients with a varus deformity 20degrees (group B). The PFC Sigma implants were used in both groups. The mechanical axis and implant position were measured by 2 observers according to the reontgenographic evaluation system of the American Knee Society. RESULTS: There was no significant difference in alpha, beta, delta angle and mechanical axis between group I and II. There was a significant difference in the gamma angle between group I and II (p20degrees tended to have more postoperative varus mechanical alignment than those with a preoperative varus deformity between 10degrees and 20degrees after TKA. More careful attention during the registration of the femoral mechanical axis should be paid in patients with a larger varus deformity in TKA using a computer-assisted navigation system. On the other hand, a reasonable mechanical valgus angle should be considered in femoral bone cutting for a varus deformity of the distal femur in conventional TKA. In addition, inadequate positioning of intramedullary rod should be recognized in conventional TKA.

Evaluation of Bone Cutting Error of the Total Knee Arthroplasty with Computer-assisted Navigation

PURPOSE: To investigate the degree of bone cutting errors and its deviation and to evaluate the differences between a planned value before sawing and an achieved value after sawing in total knee arthroplasty (TKA) with computer-assisted navigation system. MATERIALS AND METHODS: 95 knees of 95 patients(81 females and 14 males) who underwent TKA with computer-assisted navigation (Orthopilot(R), AESCULAP) were studied. The planned value according to cutting block position and the achieved value according to achieved cutting planes were measured and compared. The bone cutting error which means a difference between the achieved value and the planned valued in each plane were statistically analysed. RESULTS: On each cutting planes, there were significant differences between planned values and measured values in coronal and sagittal plane of tibia and sagittal plane of femur (respectively p=0.0008, p=0.0002, p<0.0001), but coronal plane of femur showed insignificant difference (p=0.39). There was significant difference between bone cutting errors with valgus 0.05degrees (SD+/-0.66) in coronal plane and extension 0.47degrees (SD+/-0.91) in sagittal plane of femur and valgus 0.31degrees (SD=+/-0.80) in coronal plane band extension 0.21degrees (SD+/-2.09) in sagittal plane of tibial cutting (respectively p=0.0012, p<0.0001). CONCLUSION: Achieved values of bone cutting in coronal and sagittal plane of tibia and sagittal plane of femur on TKA were significantly different from planned values. The deviation of bone cutting errors showed valgus and extension in both femur and tibia. The bone cutting errors in sagittal plane were more significant than the coronal plane. Surgeons should take this bone cutting errors into consideration on operation.

Analysis of errors of computer-assisted cervical pedicle screw installation / 中国矫形外科杂志

[Objective]To evaluate the accuracy of computer-assisted cervical pedicle screw installation and discuss the reasons of screw malposition.[Method]Totally 144 cervical pedicle screws were installed by computer-assisted navigation in 25 patients with lower cervical spinal disease.All the patients were examined by X-rays and CT after operation.Screw position and direction were measured on the sagittal and transsection image of intraoperative navigation and post-operative CT.The result was analyzed statistically.[Result]Two screws perforated the upper pedicle wall,3 deviated from the lateral pedicle wal1.There was no statistical difference in screw position or direction between navigation and CT image.Navigational images were based on the principle of rigid tissue.[Conclusion]Computer-assisted navigation can improve the accuracy of cervical pedicle screw installation.Screw malposition is responsible for the excursion phenomenon.

Study of common problems in the treatment of thoracolumbar fracture and the clinical application of computer assisted navigation technique / 中国矫形外科杂志

[Objective]To study the methods and clinical results of infrared fluoroscopic navigation guiding system guided operations for the treatment of thoracolumbar fracture and analysis the common problems in the treatment of thoracolumbar fracture.[Method]A retrospective analysis was carried out in 56 cases with thoracolumbar fracture and dislocation from March 2003 to December 2006.There were 36 males and 20 females,ranging from 18-56 years(average 35 years).Segments involved:T11 10 cases,T12 13 cases,L1 21 cases,L29 cases,L3 3 cases.According to the classification of AO:there were 26 cases of type A,17 cases of type B,13 cases of type C.According to the classification of ASIA:there were 11 cases of type A,18 cases of type B,13 cases of type C,8 cases of type D,6 cases of type E,among which 35 cases had neurological disfunction symptom.Operation were performed under the suspection of computer assisted navigation system,32 cases underwent posterior decompession approach,withAF transpedicular screw internal fixation in thoracolumbar spine.Fifteen cases underwent anterior approach spondylectomy with bone graft and plate internal fixation.Other cases underwent conservative treatment.The vertebral stabilization and the struction of the three columns were reconstructed.[Result]The mean operati on time was 200 min,ranging from 160 to 300 min.The mean blood loss during operation was 1 000 ml ranging from 800 to 2 000 ml.All patients were followed up for 6 to 36 months(10 months on average).Neurological status improved to A ASIA grade in 4 cases,B grade 5 cases,C grade 11 cases,D grade 14 cases,E grade 22 cases.[Conclusion]The patient had remarkable improvement in clinical relief.In order to achive the best effect in the treatment of thoracolumbar fracture,correct treatments of primary trauma and injury type and appropriate management are necessary for the treatment of thoracolumbar fracture.Also,computer assisted navigation system enhances accuracy and further improves the safety of spine surgery.

Comparative Analysis of Image-free Navigation System-Assisted TKA and Conventional TKA

PURPOSE: To compare the roentgenographic results between Image-free navigation system-assisted total knee arthroplasty (TKA) using the OrthoPilot(R) and conventional TKA. MATERIALS AND METHODS: Of 120 primary TKA that operated by one surgeon, 60 cases were operated with a Image-free navigation system (OrthoPilot(R) 4.0, Aesculap, Tuttlingen, Germany) (group A) and 60 cases were operated with conventional method (manual alignment system) (group B). The alignment of the lower extremity and the position of the components were determined on postoperative long-leg standing anteroposterior radiogram and lateral radiogram. RESULTS: Mechanical axis was significantly more accurate in group A than group B(95% compared with 80%). The coronal inclination of femoral component to mechanical axis (theta) was significantly more accurate in group A than group B(96.7% compared with 80%). There were no significant differences between two groups in the sagittal inclination of femoral component(gamma), the coronal inclination of tibial component (beta) and the sagittal inclination of tibial component(delta). In all five measurements being excellently implanted, a significantly higher number was in group A(60% compared with 40%). CONCLUSION: Image-free navigation system-assisted TKA using the OrthoPilot(R) led to significantly increased precision of restoration of the alignment of the lower extremity and the position of the components compared with the conventional method. Potential benefits in long-term outcome and functional improvement require further investigation.

Intraoperative versus Postoperative Measurement in Total Knee Arthroplasty using Computer-Assisted Orthopaedic Surgery (CAOS): Accuracy of CAOS / 대한정형외과학회잡지

PURPOSE: The purpose of this research was to compare the intra-operative and post-operative measured angle in total knee arthroplasty (TKA) and to evaluate the postoperative improvement in the mechanical axis. MATERIALS AND METHODS: Forty TKAs were performed using CAOS between February and May 2004. We measured the mechanical axis in the preoperative orthograms. After inserting the implant, we measured the femoral component angle (FCA), tibial component angle (TCA) and tibial component slope (TCS) using the verification tool in CAOS, on the post-operative orthogram and X-ray of the lateral tibial view, 2 observers measured the FCA, TCA, TCS and mechanical axis. RESULTS: The mean FCA, TCA and TCS using the verification tool in CAOS, were valgus 0.03+/-0.85degrees, valgus 0.49+/-1.02degrees, nd 4.26+/-1.64degrees. The mean FCA, TCA and TCS by observer 1 were valgus 0.67+/-1.24degrees, varus 0.54+/-1.54degrees, and 4.57+/-1.74degrees and those by observer 2 were valgus 0.48+/-1.17degrees, varus 0.52+/-1.44degrees, and 4.24+/-2.83degrees. There was a positive correlation between the measured angle by respective observers and the angle measured by the CAOS (p<0.05). The mechanical axis by observers 1 and 2 improved from varus 13.96degrees to valgus 0.04degrees and from varus 14.12degrees to valgus 0.08degrees respectively. CONCLUSION: CAOS affords the possibility of precisely placing the femoral and tibial components. The angles measured by the respective observers and in the CAOS were significantly correlated.

Pedicle Screw Placement under the Guidance of Computer-Assisted Navigation System / 中国微创外科杂志

Objective To investigate the clinical value of computer-assisted navigation system (CANS) in pedicle screw placement. Methods From August 2002 to June 2006, we carried out 66 cases of pedicle screw placement under the guidance of CANS; 66 cases of traditional pedicle screw placement were set as a control. Results The mean operation time of CANS group was significantly shorter [(142.3?5.3) min vs (173.4?7.1) min; t=-28.301, P=0.000] and the blood loss was significantly fewer [(798.3?10.9)ml vs (912.2?14.3) ml; t=-51.463, P=0.000] than those in the control. X-ray and CT scan respectively showed that the placement of pedicle screw in CANS group was significantly more accurate than that in the control. (?2=29.424, P=0.000; ?2=36.829, P=0.000). Conclusion Pedicle screw placement under the guidance of CANS is more accurate, safe, and micro-invasive than traditional operation.