The purpose of this study is to establish and apply a correction method for titanium alloy implant in spinal IMRT plan, a corrected CT-density table was revised from normal CT-density table to include the density of titanium alloy implant. Dose distribution after and before correction were calculated and compared to evaluate the dose deviation. Plans were also copied to a spinal cancer simulation phantom. A titanium alloy fixation system for spine was implanted in this phantom. Plans were recalculated and compared with the measurement result. The result of this study shows that the max dose of spinal cord showed significant difference after correction, and the deviation between calculation results and measurement results was reduced after correction. The method for expanding the range CT-density table, which means that the density of titanium alloy was included, can reduce the error in calculation.
Radiotherapy, Intensity-Modulated/methods* ; Titanium ; Radiotherapy Dosage ; Alloys ; Radiometry/methods* ; Radiotherapy Planning, Computer-Assisted/methods*

OBJECTIVE: To propose a sensitivity test method for geometric correction position deviation of cone-beam CT systems. METHODS: We proposed the definition of center deviation and its derivation. We analyzed the influence of the variation of the three-dimensional spatial center of the steel ball point, the projection center and the size of the steel ball point on the deviation of geometric parameters and the reconstructed image results by calculating the geometric correction parameters based on the Noo analytical method using the FDK reconstruction algorithm for image reconstruction. RESULTS: The radius of the steel ball point was within 3 mm. The deviation of the center of the calibration parameter was within the order of magnitude and negligible. A 10% Gaussian perturbation of a single pixel in the 3D spatial coordinates of the steel ball point produced a deviation of about 3 pixel sizes, while the same Gaussian perturbation of the 2D projection coordinates of the steel ball point produced a deviation of about 2 pixel sizes. CONCLUSION The geometric correction is more sensitive to the deviation generated by the three-dimensional spatial coordinates of the steel ball point with limited sensitivity to the deviation generated by the two-dimensional projection coordinates of the steel ball point. The deviation sensitivity of a small diameter steel ball point can be ignored.
Algorithms ; Calibration ; Cone-Beam Computed Tomography ; Steel

The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.
Humans ; Stainless Steel ; Powders ; Cardiovascular System ; Constriction, Pathologic

Znic (Zn) alloys with good cytocompatibility and suitable degradation rate have been a kind of biodegradable metal with great potential for clinical applications. This paper summarizes the biological role of degradable Zn alloy as bone implant materials, discusses the mechanical properties of different Zn alloys and their advantages and disadvantages as bone implant materials, and analyzes the influence of different processing strategies (such as alloying and additive manufacturing) on the mechanical properties of Zn alloys. This paper provides systematic design approaches for biodegradable Zn alloys as bone implant materials in terms of the material selection, product processing, structural topology optimization, and assesses their application prospects with a view to better serve the clinic.
Orthopedics ; Zinc ; Alloys ; Dental Materials ; Prostheses and Implants

OBJECTIVE: To analyze the effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture. METHODS: From January 2016 to June 2021, 26 patients with Ideberg typeⅡglenoid fractures were treated with trans-axillary lag screw combined with supporting plate, including 15 males and 11 females. The age ranged from 21 to 75 years, with an average of (43.12±6.56) years old. The Constant-Murley Shoulder joint Scale and University of California at Los Angeles (UCLA) score were used to evaluate the function and clinical efficacy of shoulder joint. RESULTS: All patients were followed up, and the duration ranged from 19 to 42 months, with an average of (30.6±10.5) months. One year after surgery, the Constant-Murley score increased from preoperative 34.9±2.5(ranged, from 28 to 47) to 87.2±6.8(ranged, from 70 to 95). The UCLA score improved from preoperative 17.9±1.7(9 to 25) to 33.1±2.3(29 to 35). Seventeen patients got an excellent result, with 7 good, and 2 fair. None of the patients had infection, screw, and plate loosening, fracture, and other complications after surgery. Two patients had different degrees of Chronic pain in the shoulder during the follow-up period. CONCLUSION The treatment of Ideberg typeⅡscapular glenoid fractures through axillary approach with lag screws and supporting steel plates has the advantages of convenient exposure, direct visual restoration of the normal anatomical shape of the scapular glenoid, selection of suitable positions for screw and steel plate placement, achieving better treatment results, and fewer complications. It is an effective and reliable surgical method.
Female ; Male ; Humans ; Young Adult ; Adult ; Middle Aged ; Aged ; Scapula ; Bone Plates ; Bone Screws ; Fractures, Bone ; Steel ; Pelvis

On November 17, 2013, the Second Affiliated Hospital of Kunming Medical University admitted a 23-year-old male patient with a high-temperature steel bar penetration injury from scrotum to buttocks who was transferred from another hospital. Expanded debridement, suture, and drainage of the perineum, right thigh, and right hip were performed as soon as possible after admission. A sputum suction tube was used as the guide mark for expanded debridement during the operation to ensure the accuracy of the direction and scope of expanded debridement. The incision was treated with vacuum sealing drainage (VSD) and full drainage. On the 20^th day after the operation (the 25^th day after admission), the unhealed wound was transplanted with split-thickness skin graft from the right thigh, and the drainage of the operation area and dressing change were strengthened. On the 53^rd day after injury, the patient was discharged after complete wound healing. This case suggests that VSD after early debridement is an effective means to treat high-temperature steel bar penetration injuries.
Adult ; Buttocks ; Debridement ; Drainage ; Humans ; Male ; Negative-Pressure Wound Therapy ; Scrotum/surgery* ; Skin Transplantation ; Steel ; Temperature ; Treatment Outcome ; Young Adult

To solve the problems of small one-time ablation range and easy charring of the tissue around the electrode associated with the tumor radiofrequency ablation needle, based on the multiphysical field coupling analysis software COMSOL, the effects of needle material, the number of sub needles and the bending angle of sub needles on the ablation effect of radiofrequency ablation electrode needle were studied. The results show that compared with titanium alloy and stainless steel, nickel titanium alloy has better radiofrequency energy transmission efficiency and it is the best material for electrode needle. The number of sub needles has a great influence on the average necrosis depth and the maximum necrosis diameter. Under the same conditions, the more the number of sub needles, the larger the volume of coagulation necrosis area. The bending angle of the needle has a great effect on the maximum diameter of the coagulated necrotic area, but has little effect on the average necrotic depth. Under the same other conditions, the coagulation necrosis area formed by ablation increased with the increase of the bending angle of the sub needle. For the three needles with bending angles of 60 °, 90 ° and 120 ° analyzed in this paper, the one with bending angle of 120 ° can obtain the largest coagulation necrosis area. In general, the design of nickel titanium alloy with 120 ° bending 8-pin is the optimal. The average depth of radiofrequency ablation necrosis area is 32.40 mm, and the maximum necrosis diameter is 52.65 mm. The above optimized design parameters can provide guidance for the structure and material design of tumor radiofrequency ablation needle.
Humans ; Needles ; Temperature ; Catheter Ablation/methods* ; Necrosis ; Neoplasms/surgery* ; Alloys

OBJECTIVE: To explore the technique of autogenous bone graft combined with plate fixation in total knee arthroplasty(TKA) with severe proximal medial tibial bone defect. METHODS: From March 2012 to October 2018, 21 patients (9 males and 12 females) with severe bone defects in the proximal medial tibia during primary total knee arthroplasty were treated with autogenous structural bone grafting and steel plate fixation, with an age of 61 to 77 years old with an average of (69.6±9.1) years and a course of 64 to 257 months with an average of (73.6±170.7) months. According to Rand classification, there were 13 cases of type Ⅲb and 8 cases of type Ⅳb. Postoperative complications were observed, and knee joint function was evaluated by the Hospital for Special Surgery (HSS) score and SF-36 quality of life score. RESULTS: All 21 patients were followed up for 37 to 64 months with an average of (49.5±13.7) months. The incisions of all patients healed smoothly, and 2 patients developed lower limb intermuscular venous plexus thrombosis after operation. There were no periprosthetic infection, loosening of prosthesis and other complications. The autogenous bone grafts of all patients achieved bony healing during postoperative X-ray follow-up, and the healing time was 8 to 13 months with an average of (10.1±2.3) months. The HSS score of patients increased significantly from 30 to 48 with an average of (53.4±4.2) before operation to 75 to 92 with an average of (81.2±8.4) at the final follow-up (P<0.05). The SF-36 quality of life score of patients after operation was significantly different from that before operation (P<0.05). CONCLUSION The technique of autogenous bone graft combined with steel plate fixation can achieve satisfactory osseointegration effect in the treatment of severe proximal tibial bone defects in primary knee arthroplasty, with less complications and obvious improvement in knee function.
Male ; Female ; Humans ; Middle Aged ; Aged ; Arthroplasty, Replacement, Knee/methods* ; Tibia/transplantation* ; Bone Transplantation/methods* ; Quality of Life ; Transplantation, Autologous ; Steel

OBJECTIVE: To develop a new type of puncture needle for indwelling needle, which can overcome the performance problems of the existing puncture needle, reduce producing cost, and enhance clinical operability. METHODS: In this design, solid needle thread is used to replace the traditional hollow pipe thread, three cutting edges are used to replace the existing two cutting edges, and the shaft edge form (the needle tip is on the needle thread's axis) is used to replace the original back blade or edge blade; the slot on the side of the solid core wire is used to replace the hollow and side hole on the traditional pipe. Finally, a new solid core puncture needle is formed by a section of solid core steel wire with a spiral groove, the cross-section of which is a circular slotted needle with a triangular shape at one end. Through the comparative analysis of stiffness mutation and puncture force in the experiment, the characteristics and advantages of new puncture needle are reflected. RESULTS: The new solid core needle can meet the need of puncture in the course of treatment, and can avoid the potential risk caused by the rigidity mutation of the needle used in the traditional indwelling needle, at the same time, it also has the space to reduce the demand of needle diameter, that means it has the potential to develop smaller needle products. CONCLUSIONS The new type of trocar puncture needle, from hollow to solid core, can not only meet the basic requirements of puncture and observation of blood return, but also can avoid the risk of traditional puncture needle due to stiffness mutation, the utility model also has the advantages of better performance (less puncture force) and larger expansion space.
Needles ; Punctures ; Steel ; Surgical Instruments

Objective: To analyzes the various occupational health investment and occupational health output of a steel enterprise, and propose a reasonable occupational health investment plan for this enterprise. Methods: In march 2016, various occupational health input and output data of various branches of an iron and steel company in 2015 were collected, and the efficiency of occupational health inputs and outputs of each branch was evaluated using data envelopment analysis (DEA) , and the branches with non-optimal efficiency were adjusted to propose a reasonable occupational health investment plan. Results: Among the branch plants investigated by this steel company, the occupational health input-output efficiency values of ironmaking north plant, power plant, hot rolling plant and stainless steel plant were 1, while the occupational health input-output efficiency of gas making plant, cold rolling plant, metallurgical furnace charge plant, coking plant, ironmaking south plant and long product plant were not the best, and the cold rolling plant has the lowest efficiency value of 0.759. For the cold rolling plant, only the parameters of acid rolling plant satisfy α=1 and s(-)=0, s(+)=0, while the remaining four workshops do not meet. After adjusting the inputs of each part according to the parameters, the occupational health output of the remaining four workshops can reach 1.7044, 2.0238, 1.3152 and 1.2136 times of the current workshop, respectively. Adjustment plans for other branch factories with unreasonable investment structures are also presented in the corresponding tables. Conclusion: The occupational health investment structure of the ironmaking south plant and other branches in this steel enterprise is unreasonable, and the adjustment using data envelopment analysis can maximize the benefits of its occupational health output.
Financial Management ; Iron ; Metallurgy ; Occupational Health ; Steel