Objective To study the accuracy of preoperative planning and postoperative satisfaction of prosthesis posi?tion by applying the personal surgical cutting guide (PSCG) to total knee arthroscopy (TKA) based on 3D printing technique. Meth?ods In this randomized study, 20 patients were selected from August 2014 to October 2015, who were randomly divided into two groups. In PSCG group, 4 males and 6 females were enrolled, with a mean age of 70.9±6.69 (from 59 to 78) years. In con?ventional instrumentation group, 2 males and 8 females were enrolled, with a mean age of 69.9 ± 6.35 (from 58 to 77) years. The conventional instrumentation group was treated with conventional TKA, while the PSCG group was treated with personal surgical cutting guides. Then the knee valgus angle of patients, the angle between prosthesis components on the coronal and the sagittal plane of two groups were evaluated. Subsequently the correlation of the actual osteotomy amount, the valgus angle, caster angle, external rotation angle between intra? and preoperative planning were compared in the PSCG group. Results Compared with the ideal value of each angle, the mean deviation of the hip?knee?ankle angle 0.77°±0.51°, frontal femoral compo?nent angle 0.37° ± 0.53° and frontal tibial component angle 0.11° ± 0.24° showed statistically significant difference between two groups (P<0.05). The mean deviation of the lateral femoral component angle and the lateral tibial component angle (respectively 8.26°±0.85°, 0.71°±0.77°) were smaller than that of the conventional instrumentation group, while the differences all had no statis?tically significant difference (P>0.05). The actual osteotomy amount, the valgus angle, caster angle, external rotation angle corre?lated well between intra?and preoperative planning (t=-2.547, 3.864, 0.537,-0.040,-1.290, P>0.05). Conclusion TKA assist?ed by PSCG can make lower extremity alignment and accuracy of prosthesis implantation more accurate compared with convention?al TKA, especially in hip?knee?ankle angle, frontal femoral component angle and frontal tibial component angle.

BACKGROUND:With significantly individual differences in the anatomy of the knee joint, traditional total knee replacement is difficult to accurately predict the position of locating limb alignment, size of the prosthesis and osteotomy amount of patients during operation. OBJECTIVE:To investigate the clinical effect of total knee replacement based on the assistance of medical image reconstruction, computer-aided design technology and 3D-printing personalized surgical navigation template. METHODS:Medical image data of patients were col ected using CT or magnetic resonance scanning equipment. The three-dimensional reconstruction of the bone was conducted by two-dimensional medical image processing technology. The navigation template was designed by computer-aided design technology. The personalized surgical navigation templates were produced by 3D printing technology, and the clinical total knee replacement was conducted. The postoperative results were evaluated using imageology. RESULTS AND CONCLUSION:Arigin 3D Pro (Arigin Medical Co., Ltd.) can accurately reconstruct a three-dimensional model of the lower limb bones. The three-dimensional design software Arigin Surgical Templating by their independent research and development can precisely pinpoint related lower limb axis, including limb alignment, rotation axis of the femur and osteotomy reference point. The personalized navigation template we researched and produced for knee surgery fitted tightly with femoral condyle and tibial plateau bone anatomy during operation, without significant movement. The deviation of patients’ limb alignment was less than 3° after total knee replacement.

Objective: To investigate the effects of exposing Trichophyton rubrum fungus to microwaves at different intensities in terms of the activity of succinic dehydrogenase and beta-(1, 3)-D-glucan synthase. Methods: Trichophyton rubrum organisms were randomly divided into a control group and experimental groups. The experimental groups were incubated at 27 ℃ after direct radiation with 2450 MHz microwaves at 20, 40, 60 or 80 W for 15 min, repeated 8 times. The control group was incubated without any irradiation. Thirty days later, the beta-(1, 3)-D-glucan synthase and succinate dehydrogenase activities were determined using enzyme-linked immunosorbent assays. Results: The enzymatic activity decreased gradually with increasing radiation intensity. When the output power was 80 W, the beta-(1, 3)-glucan-synthase-D activity was 0.730±0.74 U/ml and that of the succinate dehydrogenase was 1.828±1.774 U/L, both significantly lower than in the groups subjected to less powerful irradiation. Conclusions Microwave radiation can decrease the enzymatic activity of Trichophyton rubrum in a dose-dependent manner. Higher intensity is more effective. Microwave irradiation can decrease the activity of succinate dehydrogenase and beta-(1, 3)-glucan synthase from Trichophyton rubrum in vitro, resulting in the destruction of fungal cell walls and interfering with the tricarboxylic acid cycle, furthering cell death. Moreover, the temperature change possibly also helps promote the biological effects of microwave radiation.