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BACKGROUND: The anatomical structure of cervical spine is complex, and the important structures of blood vessels, nerves, esophagus and trachea are adjacent to the tumor. The operation is difficult. OBJECTIVE: To explore the application of three-dimensional (3D) printing model in surgical resection and reconstruction of cervical tumor. METHODS: Eleven patients with cervical tumors, who were treated in the Gansu Provincial Hospital from September 2016 to December 2018, were selected, including 7 males and 4 females, at the age of 35-68 years. Eleven patients were scanned by cervical CT before operation. The image information obtained by CT was saved in DICOM format, and then the data were imported into Mimics 3D modeling software to reconstruct the 3D model. Finally, the reconstruction results were imported into the 3D printer in STL format, and the 1 ∶ 1 anatomical model was printed layer by layer according to the 3D model. According to the 3D printed model, the surgical resection and reconstruction plan of cervical tumor was made. After 6-12 months of follow-up, the visual analogue scale score and Oswestry dysfunction index were compared before and after surgery. This study was approved by the Ethics Committee of Gansu Provincial Hospital. RESULTS AND CONCLUSION: (1) Eleven cases were operated successfully, and no serious complications such as spinal cord, nerve root and vertebral artery injury occurred; postoperative X-ray reexamination showed that the lesion site was completely removed, and the implant was in a good position without loosening. (2) The visual analogue scale score and Oswestry dysfunction index of eleven patients were significantly improved in 1 week, 1 and 3 months after operation (P < 0.05). (3) The results showed that 3D printing model could make a complete resection and reconstruction plan before operation, including the specific resection scope, fixed segment, screw and steel plate size, familiar with the anatomical relationship between the focus and the surrounding tissue, avoid the injury of important nerves and blood vessels during operation, reduce the risk of operation and improve the clinical effect.
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Objective To explore the role of a customized 3D printing guide in total hip arthroplasty (THA).Methods A retrospective analysis was performed of the 60 patients who had been treated by THA for avascular necrosis of the femoral head at Department of Orthopaedics and Traumatology,Foshan Hospital of Traditional Chinese Medicine from January 2018 to May 2019.Half of them used the personalized 3D printing guide in THA and half did not.In the guide group there were 17 men and 13 women with an age of 53.4 ± 8.9 years while in the conventional group 19 men and 11 women with an age of 54.7 ± 9.4 years.The acetabular cups were orientated at an abduction angle of 40° and an anteversion angle of 15°.The intraoperative blood loss,operation time and acetabular abduction angle were compared between the 2 groups.Results The 2 groups were comparable due to insignificant differences between them in gender,age,body mass,cause of disease or staging of avascular necrosis of the femoral head (P ＞0.05).The guide group had significantly less intraoperative blood loss (286.7 ± 150.8 mL) and operation time (90.5 ± 34.4 min) than the conventional group did (438.3 ± 292.6 mL and 115.6 ± 58.6 min) (P ＜0.05).The acetabular cup abduction was 38.9° ± 4.2° in the guide group and 37.2° ± 5.5° in the conventional group,showing no significant difference (t =1.315,P =0.194).Conclusion Use of a personalized 3D printing guide in THA can shorten the time for installation of an acetabular prosthesis and reduce the amount of intraoperative blood loss,but it leads to insignificant difference in the postoperative acetabular cup abduction compared with no use of the guide.
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Objective@#To explore the role of a customized 3D printing guide in total hip arthroplasty (THA).@*Methods@#A retrospective analysis was performed of the 60 patients who had been treated by THA for avascular necrosis of the femoral head at Department of Orthopaedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine from January 2018 to May 2019. Half of them used the personalized 3D printing guide in THA and half did not. In the guide group there were 17 men and 13 women with an age of 53.4±8.9 years while in the conventional group 19 men and 11 women with an age of 54.7±9.4 years. The acetabular cups were orientated at an abduction angle of 40° and an anteversion angle of 15°. The intraoperative blood loss, operation time and acetabular abduction angle were compared between the 2 groups.@*Results@#The 2 groups were comparable due to insignificant differences between them in gender, age, body mass, cause of disease or staging of avascular necrosis of the femoral head (P>0.05). The guide group had significantly less intraoperative blood loss (286.7±150.8 mL) and operation time (90.5±34.4 min) than the conventional group did (438.3±292.6 mL and 115.6±58.6 min) (P< 0.05). The acetabular cup abduction was 38.9°±4.2° in the guide group and 37.2°±5.5° in the conventional group, showing no significant difference(t=1.315, P=0.194).@*Conclusion@#Use of a personalized 3D printing guide in THA can shorten the time for installation of an acetabular prosthesis and reduce the amount of intraoperative blood loss, but it leads to insignificant difference in the postoperative acetabular cup abduction compared with no use of the guide.
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Objective To explore the clinical efficacy of 3D printing technique in assisting sacroiliac screwing in combination with front ring nail-rod system for treatment of unstable pelvic fractures.Methods From July 2015 to June 2017,3D printing technique was used to assist the sacroiliac screwing in combination with front ring nail-rod system for 16 patients with unstable pelvic fracture at Orthopaedic Center,The Fourth People's Hospital of Zigong.They were 9 males and 7 females,aged from 19 to 60 years (average,39.8 years).By the Tile classification,5 cases were type B1,6 type B2,3 type B3 and 2 type C.Their operation duration,bleeding,fluoroscopy frequency,incision length,postoperative fracture reduction,success rate of sacroiliac screwing,accuracy of sacroiliac screwing,perioperative complications,weight-bearing exercise time,fracture healing time and the Majeed scores at the last follow-up were documented.Results All the 3D models and navigation templates were successfully designed and printed.Surgery succeeded in all the patients.Follow-ups ranged from 6 to 18 months,averaging 13.3 months.The bleeding ranged from 100 to 250 mL,averaging 162.4 mL;the operation duration ranged from 60 to 120 min,averaging 73.2 min;the intra-operative fluoroscopy frequency ranged from 13 to 31 times,averaging 17.4 times;the incision length ranged from 16 to 32 cm,averaging 21.1 cm.All the incisions healed by the first intention and all the fractures obtained osseous union after 90 to 120 d (average,102.3 d).No significant complications like neurovascular injury or pulmonary embolism happened.The weight-bearing exercise time ranged from 25 to 40 d,averaging 31.5 d.According to the Matta imaging scores,the reduction was rated as excellent in 12 cases and good in 4.Altogether 28 screws were inserted with a success rate of 100％.Compared with the preoperative simulated screwing,the actual screwing angle deviated postoperatively by 0.12° ± 0.32°,the X axis by 0.36 ± 1.24 mm,the Y axis by 0.36 ± 1.24 mm and the Z axis by 0.22 ± 1.26 mm,showing no statistically significant difference between the actual 3D deviations and the test value of 0 (P ＞ 0.05).Conclusion In the treatment of unstable pelvic fractures,3D printing technique can be used in preoperative preparation of the connecting rod in the front ring nail-rod system to assist the sacroiliac screwing,significantly shortening the operation duration,reducing bleeding,ensuring safe and accurate screwing,and facilitating functional recovery.
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<p><b>OBJECTIVE</b>The aim of this study is to build a digital dental model with cone beam computed tomography (CBCT), to fabricate a virtual model via 3D printing, and to determine the accuracy of 3D printing dental model by comparing the result with a traditional dental cast.</p><p><b>METHODS</b>CBCT of orthodontic patients was obtained to build a digital dental model by using Mimics 10.01 and Geomagic studio software. The 3D virtual models were fabricated via fused deposition modeling technique (FDM). The 3D virtual models were compared with the traditional cast models by using a Vernier caliper. The measurements used for comparison included the width of each tooth, the length and width of the maxillary and mandibular arches, and the length of the posterior dental crest.</p><p><b>RESULTS</b>3D printing models had higher accuracy compared with the traditional cast models. The results of the paired t-test of all data showed that no statistically significant difference was observed between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>Dental digital models built with CBCT realize the digital storage of patients' dental condition. The virtual dental model fabricated via 3D printing avoids traditional impression and simplifies the clinical examination process. The 3D printing dental models produced via FDM show a high degree of accuracy. Thus, these models are appropriate for clinical practice.</p>
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Objective To research and prepare the individualized knee in vitro guided plate by 3D printing technique and to investigate the feasibility of its application in 8-plate epiphysiodesis.Methods Twelve children patients with knee varus or valgum in our hospital from January 2014 and November 2016,7 boys and 5 girls,average age of 8.2 years old,were performed the lower extremity continuous spiral CT scanning in the knee straight position.The Dicom format stored CT data were imported into software Mimics 15.0 for reconstructing the knee joint 3D model.The knee joint data after reconstruction were guided into software Geomagic1 1.0 with the.stl format.According to the demand that screws without perforating epiphyseal and joint surface,paralle ling to the epiphyseal and locating in the anterior-posterior median line of epiphyseal,the 8-plate placing screw navigation template was designed and printed by using the 3D printing technique;the 8-plate plate and screw internal fixation was conducted by intraoperative template location.The placed screw position was evaluated by postoperative CT.Results The imaging identification showed that 8-plate epiphysiodesis by using 3D printing individualized in vitro guided plate had accurate screw placement.The cases were followed from 6 months to 2 years,the satisfactory orthopedic effect was obtained in all cases.Conclusion Preparing the individualized knee in vitro guided plate by applying 3D printing technique in assisted 8-plate epiphysiodesis for treating child knee varus or valgum has accurate screw position and satisfactory effect.