scholarly journals Anatomical conditions and patient-specific locked navigation templates for TSS placement

2020 ◽  
Author(s):  
Chao Wu ◽  
jiayan deng ◽  
jian pan ◽  
tao li ◽  
Lun Tan
Keyword(s):  
Entry Point ◽  
Screw Placement ◽  
Patient Specific ◽  
Short Axis ◽  
Sacroiliac Screw ◽  
Nerve Root Injury ◽  
Significant Difference ◽  
Sacroiliac Screws ◽  
Ct Data ◽  
Navigation Template

Abstract Objective To analyse the anatomical conditions of transverse sacroiliac screws about the S1 and S2 segments in order to develop and validate a locked navigational template for transverse sacroiliac screw placement. Methods The CT data of 90 normal sacra were analysed. The long axis, short axis and lengths of transverse sacroiliac screw cancellous corridors were measured through 3D modelling. A patient-specific locked navigation template based on simulated screws was designed and 3D printed and then used to assist in transverse sacroiliac screw placement. The operative time, intraoperative blood loss, incision length, and radiation times were recorded. The Matta criteria and grading score were evaluated. The entry point deviation of the actual screw placement relative to the simulated screw placement was measured, and whether the whole screw was in the cancellous corridor was observed.Results S1 screws with a diameter of 7.3 mm could be inserted into 69 pelvises, and S2 screws could be inserted in all pelvises. The S1 cancellous corridor had a long axis of 25.44±3.32 mm in males and 22.91±2.46 mm in females, a short axis of 14.21±2.19 mm in males and 12.15±3.22 mm in females, a corridor length of 153.07±11.99 mm in males and 151.11±8.73 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 35.96±10.31% in males and 33.28±7.2% in females. There were significant differences in the corridor long axis and corridor short axis between sexes (p<0.05), and there were no significant differences in corridor length and proportional position of the optimal entry point in the long axis of the cancellous corridor between sexes (p>0.05). The S2 cancellous corridor had a long axis of 17.58±2.36 mm in males and 16±2.64 mm in females, a short axis of 14.21±2.19 mm in males and 13.14±2.2 mm in females, a corridor length of 129.95±0.89 mm in males and 136.5±7.96 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 46.77±9.02% in males and 42.25±11.95% in females. There were significant differences in the long axis, short axis and corridor length (p<0.05). There was no significant difference in the proportional position of the optimal entry point in the long axis of the cancellous corridor (p>0.05). A total of 20 transversal sacroiliac screws were successfully inserted into 10 patients with the assistance of locked navigation templates. Nineteen screws were grade 0, 1 screw was grade 1, and there were no postoperative complications of infection or nerve root injury. All screw entry point deviations were shorter than the short axis of the cancellous corridor, and all screws were located completely within the cancellous corridor.Conclusion Approximately 76% of males and females can accommodate screws with diameters of 7.3 mm in S1, and all persons can accommodate the same screw in S2. From the standard lateral perspective of the sacrum, the optimal entry point of the transverse screw is in the first 1/3 of the cancellous corridor for S1 and the centre of the cancellous corridor for S2. The patient-specific locked navigation template assisted in transverse sacroiliac screw placement with little trauma and fluoroscopy radiation and secure screw placement.

scholarly journals Anatomic Study and Assembled Navigation Template-Assisted Implantation for Anterograde Transpubic Screws

2021 ◽  
Author(s):  
Chao Wu ◽  
Danwei Shen ◽  
Jiayan Deng ◽  
Bofang Zeng ◽  
Xiangyu Wang ◽  
...  
Keyword(s):  
Blood Loss ◽  
Normal Subjects ◽  
Entry Point ◽  
Screw Placement ◽  
Incision Length ◽  
Screw Channel ◽  
Surface Distance ◽  
Inner Circle ◽  
The Difference ◽  
Navigation Template

Abstract Objective: Research the anatomical parameters of the anterograde transpubic screw corridor and evaluate the safety of anterograde transpubic screw placement assisted by the assembled navigation template.Methods: A total of 50 normal subjects, including 25 males and 25 females, underwent pelvic CT scanning in our hospital from January 2020 to September 2020. A 3D model of the ilium was established. The ilium was divided into zone Ⅰ, Ⅱ and Ⅲ according to Nakatani classification. The anterograde transpubic screw channel completely passes through zone Ⅰ and Ⅱ to form corridor A. The anterograde screw channel completely passes through zone Ⅰ, Ⅱ and Ⅲ to form corridor B. The diameter and length of the inner circle, the distance from the center of the inner circle to the posterior superior and to the inferior iliac spine of corridor A and corridor B were measured, respectively. A total of 9 patients underwent anterograde transpubic screw and transverse sacroiliac screw placement assisted by the assembled navigation template in our hospital, including 5 males and 4 females, were retrospectively analyzed. Operative time, blood loss, incision length and fluoroscopy times were recorded. Grading score and Matta score were evaluated after surgery.Results: In 50 normal subjects, the diameter of corridor A was 11.16±2.13 mm, and that of corridor B was 8.54±1.52mm, and the difference between the two corridors was statistically significant (P=0.000). The length of corridor A was 86.39±9.35 mm, and that of corridor B was 117.05±5.91 mm, with significant difference between the two corridors (P=0.000). The surface distance from the screw entry point to the posterior superior iliac spine in corridor A was 109.31± 11.06mm, and that in corridor B was 127.86± 8.23mm, the difference between the two corridors was statistically significant (P=0.000). The surface distance from the screw entry point to the posterior inferior iliac spine in corridor A was 91.16±10.34 mm, and that in corridor B was 106.92±7.91 mm. The difference between the two corridors was statistically significant (P=0.000). Nine patients successfully completed surgery, and a total of 18 sacroiliac transverse screws and 11 anterograde transpubic screws were inserted with the assistance of assembled navigation templates. The mean operation time of the 9 patients was 108.75±25.71 min, the blood loss was 141.11±50.21 ml, the incision length was 14±4.62 cm, and the intraoperative fluoroscopy was 17.89±4.01 times. Matta scores were excellent in 5 patients and good in 4 patients. One of the anterograde transpubic screw was in Grade 1, and 10 were in Grade 0. One S1 screw was in Grade 1, and 8 S1 screws were in Grade 0. Nine S2 screws were in Grade 0.Conclusions: Majority of the patients can accommodate anterograde transpubic screw s with diameter of 6.5 mm. Anterograde transpubic screw placement assisted by an assembled navigation template is clinically feasible, and with low cortical breaches.

scholarly journals Which of MIS-TLIF and TLIF Can Leads to Better Pedicle Screws Placement Accuracy and Clinical Outcomes with Navigation Guidance?

2021 ◽  
Author(s):  
JiaBin Liu ◽  
JunLong Wu ◽  
Rui Zuo ◽  
ChangQing Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Pedicle Screw ◽  
Pedicle Screws ◽  
Entry Point ◽  
Screw Placement ◽  
Transfusion Rate ◽  
Pedicle Screw Placement ◽  
Multifidus Muscle ◽  
Lower Accuracy ◽  
Significant Difference

Abstract Background Although previous studies have suggested that navigation can improve the accuracy of pedicle screw placement, there are still few studies comparing navigation-assisted transforaminal lumbar interbody fusion (TLIF) and navigation-assisted minimally-invasive TLIF (MIS-TLIF). The pedicle screw insertion entry point of navigation-assisted MIS-TLIF may be deflected from the planned entry point due to uneven bone-surface, which may result in misplacement. The purpose of this study was to explore the pedicle screws accuracy and clinical consequences of MIS-TLIF and TLIF both under O-arm navigation to determine which surgical method is better.MethodsA retrospective study of 54 patients who underwent single-segment navigation-assisted MIS-TLIF (NM-TLIF) or navigation-assisted TLIF (N-TLIF) was conducted. In addition to the patient's demographic characteristics, intraoperative indicators and complications, the ODI and VAS scores were recorded and analyzed preoperatively, at 1, 6, 12 months and at the final follow-up postoperatively. The clinical accuracy and absolute accuracy of pedicle screw placement was assessed by postoperative CT. Multifidus muscle injury were evaluated by T2-weighted MRI.ResultsCompared with N-TLIF, NM-TLIF was more advantageous in the incision length, intraoperative blood loss, drainage volume, time before ambulation, length of hospital stays, blood transfusion rate and analgesia rate (p<0.05). The ODI and VAS for low back pain scores were better than those of N-TLIF at 1 month and 6 months after surgery (p<0.05). There was no significant difference in the screw clinical qualitative accuracy (97.3% vs. 96.2%, p>0.05). The absolute quantitative accuracy results show that the axial translational error, sagittal translational error and sagittal angle error of NM-TLIF group are significantly greater than that in N-TLIF group (P<0.05). The mean T2-weighted signal intensity of multifidus muscle in the NM-TLIF group was significantly lower than that in the N-TLIF group (P<0.05)ConclusionsCompared with N-TLIF, NM-TLIF has more minimally invasive advantages, it does not yield a lower accuracy of screw placement and can achieve better symptom relief in the middle stage of postoperative recovery. However，more attention on real-time adjustment should be paid to pedicle insertion in NM-TLIF, rather than just following the entry point and trajectory of the intraoperative plan.

scholarly journals The accuracy and safety of patient-specific 3D printing screws insertion templates based on external fixation for pelvic screw insertion

10.29007/96k5 ◽  
2018 ◽  
Author(s):  
Xing-Guang Tao ◽  
Hui Liang ◽  
Fu-Gen Pan ◽  
Kai Hua Zhou
Keyword(s):  
3D Printing ◽  
External Fixation ◽  
Pelvic Fractures ◽  
Patient Specific ◽  
Sacroiliac Screw ◽  
Screw Insertion ◽  
Sacroiliac Screws ◽  
New Type ◽  
Printing System ◽  
Moderate Cost

Objective: To explore the feasibility and accuracy of the new technique of patient-specific 3D printing screws insertion template in the pelvic fractures.Methods: From January to June in 2017, 6 patients with pelvic fractures were treated by this new type of screw guide templates. Pubis screws and sacroiliac screws were inserted. The patients with external fixation were examined by CT scan before surgery. The patients-specific 3D printing templates were made with photosensitive resin by a 3D printing system to ensure the trajectory of the screws. The templates were sterilized by ethylene oxide and used during surgery. The accuracy and safety of the templates were evaluated by CT scans after surgery.Results: Totally 10 screws were inserted, including 5 pubis screws and 5 sacroiliac screws. The average surgical time for pubis screw was 12.7 min/screw, and 9.2 min/screw for sacroiliac screw. The average time of X-ray exposure was 13.3±3.6s/screw for public screw and 9.6±4.5s/screw for sacroiliac screw. All the screws were inserted in the trajectory as preoperative design and the screw axis deviation was 1.60 ± 0.2mm and 2 ± 0.3 degrees angle deviation by preoperative and postoperative CT verification. Blood loss during the surgery was minimal (12.2ml/screw). Vascular of neurologic complications or injuries did not happen. And no infection, broken screws or screw pullout occurred.ConculsionThe patient-specific screw guide template based on the external fixation can insert the screw accurately and safely with very small incision. This technique is a new kind of intraoperative screw navigations. The patient-specific 3D printing screw insertion template was user-frindly, moderate cost and enabled a radiation-reduced pelvic screw insertion.

scholarly journals Three-dimensional Digital Anatomical Measurement of Modified Sacroiliac Screws

2022 ◽  
Author(s):  
Tingguang Wang ◽  
Bei Zhao ◽  
Jun Yan ◽  
Jia Wang ◽  
Chong Chen ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Three Dimensional ◽  
Screw Placement ◽  
Sacroiliac Screw ◽  
Screw Channel ◽  
Computed Tomography Images ◽  
Sacroiliac Screws ◽  
Two Parameters ◽  
Α Angle ◽  
First Time

Abstract Purpose To rebuild a model of the pelvis and effectively simulate the trajectory of modified sacroiliac screws, we measured the parameters of each screw and screw channel and assessed the safety and feasibility of the parameters in adults.Method and materials One hundred (50 males and 50 females) normal adult pelvic CT (computed tomography) images were randomly selected and imported into Mimics software to rebuild the three-dimensional pelvis model. In these models, each ideal channel of modified screws was simulated, and then we obtained the precise parameters of screws and channels using Mimics and Three-matic software.Results The results of the comparison (right vs. left) showed that there were no significant differences in any of the angles, radius or M1SI parameters (the first modified sacroiliac). However, one parameter (BS) of M2SI (the second modified sacroiliac), two parameters (AP and BS) of M3SI (the third modified sacroiliac), and three parameters (AP、BS、L) of M4SI (the fourth modified sacroiliac) were statistically significant (P < 0.05). The result of comparison (between genders) showed that there were no significant differences in M1SI and M2SI; in contrast, the radius, length and the α angle of M3SI and M4SI were significantly different between genders (P < 0.05), and the radius of M4SI required special attention. If the radius of the limiting screw channel was >3.50 mm, 52 cases (52%, 24 males and 28 females) could not complete the M4SI screw placement among 100 samples. If the radius of the limiting screw channel was >3.0 mm, a total of 10 cases (10%, 2 males and 8 females) could not complete the M4SI screw placement.Conclusion Through the measurement of 100 healthy adult real three-dimensional pelvic models, we obtained the parameters of each modified sacroiliac screw and measured the three angles of each screw based on international coordinates for the first time, which can instruct clinical application.

scholarly journals Clinical Analysis of Single and Double Sacroiliac Screws in the Treatment of Tile C1 Pelvic Fracture

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Hong-Li Deng ◽  
Dong-Yang Li ◽  
Yu-Xuan Cong ◽  
Bin-Fei Zhang ◽  
Jin-Lai Lei ◽  
...  
Keyword(s):  
Blood Loss ◽  
Functional Recovery ◽  
Operative Time ◽  
Pelvic Fractures ◽  
Intraoperative Blood Loss ◽  
Sacroiliac Screw ◽  
Significant Difference ◽  
Sacroiliac Screws ◽  
Screw Group

We investigated the difference between fixation of single and double sacroiliac screws in the treatment of Tile C1 pelvic fractures. The data of 54 patients with Tile C1 pelvic fractures who were admitted to the trauma center of the Red Society Hospital Affiliated to Xi’an Jiaotong University between August 2016 and August 2020 were retrospectively analyzed. All patients with posterior pelvic ring injuries underwent fixation with sacroiliac screws assisted by a percutaneous robotic navigation system. The operative time, amount of intraoperative blood loss, and postoperative follow-up time between the two groups (single sacroiliac and double sacroiliac screw groups) were compared. The Matta and Majeed scores at the last follow-up were compared between the groups to evaluate fracture reduction and functional recovery. Forty-nine patients were followed up for 17.2 (±4.5) months and 16.2 (±3.4) months in the single and double sacroiliac screw groups, respectively. All patients had excellent fracture reduction immediately after surgery, according to the Matta score. All fractures healed without complications. There was no statistically significant difference in preoperative general information, amount intraoperative blood loss, intraoperative anterior ring fixation method, and postoperative follow-up time between the two groups ( P > 0.05 ). The operative time of the single sacroiliac screw group was shorter than that of the double sacroiliac screw group ( P < 0.05 ). At the last follow-up, the Matta score of the double sacroiliac screw group was significantly better than that of the single sacroiliac screw group ( P < 0.05 ), and there was no statistically significant difference in the Majeed functional scores ( P > 0.05 ). For Tile C1 pelvic fractures, double sacroiliac screw fixation of posterior ring injuries can provide a more stable treatment with no statistically significant difference in functional recovery.

Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT

2007 ◽  
Vol 46 (01) ◽  
pp. 38-42 ◽  
Author(s):  
V. Schulz ◽  
I. Nickel ◽  
A. Nömayr ◽  
A. H. Vija ◽  
C. Hocke ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
One Dimension ◽  
Patient Specific ◽  
Data Sets ◽  
Facet Joints ◽  
Lumbar Vertebral Body ◽  
Ct System ◽  
Ct Data ◽  
Attenuation Corrected

SummaryThe aim of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated. Methods: Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). Results: After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p <0.05). Conclusions: AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting leftto- right ratios. Therefore, at clinical evaluation of attenuation- corrected scans special attention should be given to possible misalignments between SPECT and CT.

scholarly journals A comparison between Asians and Caucasians in the dimensions of the femoral isthmus based on a 3D-CT analysis of 1189 adult femurs

2021 ◽  
Author(s):  
Darius M. Thiesen ◽  
Dimitris Ntalos ◽  
Alexander Korthaus ◽  
Andreas Petersik ◽  
Karl-Heinz Frosch ◽  
...  
Keyword(s):  
Proximal Femur ◽  
Strong Predictor ◽  
Matched Pair ◽  
3D Ct ◽  
Femur Fractures ◽  
Matched Pair Analysis ◽  
Significant Difference ◽  
Ct Analysis ◽  
Ct Data ◽  
The Individual

Abstract Introduction For successful intramedullary implant placement at the femur, such as nailing in unstable proximal femur fractures, the use of an implant that at least reaches or exceeds the femoral isthmus and yields sufficient thickness is recommended. A number of complications after intramedullary femoral nailing have been reported, particularly in Asians. To understand the anatomical features of the proximal femur and their ethnic differences, we aimed to accurately calculate the femoral isthmus dimensions and proximal distance of Asians and Caucasians. Methods In total, 1189 Asian and Caucasian segmented 3D CT data sets of femurs were analyzed. The individual femoral isthmus diameter was precisely computed to investigate whether gender, femur length, age, ethnicity or body mass index have an influence on isthmus diameters. Results The mean isthmus diameter of all femurs was 10.71 ± 2.2 mm. A significantly larger diameter was found in Asians when compared to Caucasians (p < 0.001). Age was a strong predictor of the isthmus diameter variability in females (p < 0.001, adjusted r2 = 0.299). With every year of life, the isthmus showed a widening of 0.08 mm in women. A Matched Pair Analysis of 150 female femurs showed a significant difference between isthmus diameter in Asian and Caucasian femurs (p = 0.05). In 50% of the cases the isthmus was found in a range of 2.4 cm between 16.9 and 19.3 cm distal to the tip of the greater trochanter. The female Asian femur differs from Caucasians as it is wider at the isthmus. Conclusions In absolute values, the proximal isthmus distance did not show much variation but is more proximal in Asians. The detailed data presented may be helpful in the development of future implant designs. The length and thickness of future standard implants may be considered based on the findings.

An evaluation of a shoulder rehabilitation class in a UK hospital following evidence-based modifications

2021 ◽  
pp. 1-8
Author(s):  
Emily Kell ◽  
John A. Hammond ◽  
Sophie Andrews ◽  
Christina Germeni ◽  
Helen Hingston ◽  
...  
Keyword(s):  
Patient Satisfaction ◽  
Shoulder Pain ◽  
Management Strategies ◽  
Cost Effective ◽  
Rehabilitation Programme ◽  
Patient Specific ◽  
Satisfaction Survey ◽  
Evidence Based ◽  
Patient Satisfaction Survey ◽  
Significant Difference

OBJECTIVES: Shoulder pain is a common musculoskeletal disorder, which carries a high cost to healthcare systems. Exercise is a common conservative management strategy for a range of shoulder conditions and can reduce shoulder pain and improve function. Exercise classes that integrate education and self-management strategies have been shown to be cost-effective, offer psycho-social benefits and promote self-efficacy. This study aimed to examine the effectiveness of an 8-week educational and exercise-based shoulder rehabilitation programme following the introduction of evidence-based modifications. METHODS: A retrospective evaluation of a shoulder rehabilitation programme at X Trust was conducted, comparing existing anonymised Shoulder Pain and Disability Index (SPADI) and Patient-Specific Functional Scale (PSFS) scores from two cohorts of class participants from 2017-18 and 2018-19 that were previously collected by the physiotherapy team. Data from the two cohorts were analysed separately, and in comparison, to assess class efficacy. Descriptive data were also analysed from a patient satisfaction survey from the 2018-19 cohort. RESULTS: A total of 47 patients completed the 8-week shoulder rehabilitation programme during the period of data collection (2018-2019). The 2018-19 cohort showed significant improvements in SPADI (p 0.001) and PSFS scores (p 0.001). No significant difference was found between the improvements seen in the 2017-18 cohort and the 2018-19 cohort. 96% of the 31 respondents who completed the patient satisfaction survey felt the class helped to achieve their goals. CONCLUSION: A group-based shoulder rehabilitation class, which included loaded exercises and patient education, led to improvements in pain, disability and function for patients with rotator cuff related shoulder pain (RCRSP) in this outpatient setting, but anticipated additional benefits based on evidence were not observed.

Design, Fabrication, and Accuracy of a Novel Noncovering Lock-Mechanism Bilateral Patient-Specific Drill Guide Template for Nondeformed and Deformed Thoracic Spines

2021 ◽  
pp. 155633162199633
Author(s):  
Mehran Ashouri-Sanjani ◽  
Shima Mohammadi-Moghadam ◽  
Parisa Azimi ◽  
Navid Arjmand
Keyword(s):  
Thoracic Spine ◽  
Sagittal Plane ◽  
Ct Scanning ◽  
Entry Point ◽  
In Vivo Studies ◽  
Patient Specific ◽  
Plane Angle ◽  
Severe Scoliosis ◽  
3D Printed

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.

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