Objective To discuss the 3D printing modeling used to assist minimally invasive fixation with hollow screws for unstable pelvic fractures.Methods From January 2014 to January 2016,137 patients with unstable pelvic fracture received minimally invasive fixation with hollow screws and obtained complete follow-up at our department.In 65 of them,the fixation was assisted by 3D printing modeling;they were 37 men and 28 women,with an average age of 33.1 ± 4.9 years.In the other 72 cases,conventional fixation was performed without assistance of 3D printing modeling;they were 45 men and 27 women,with an average age of 32.6 ±4.7 years.The 2 groups were compared in terms of operation time,frequency of intraoperative fluoroscopy,reduction quality and curative effect.Results This cohort were followed up for 6 to 15 months (average,9 months).The 3D printing modeling group needed significantly less operation time (58.6 ± 13.4 min) and intraoperative fluoroscopy (29.3 ± 3.6 frequencies) than the conventional group (72.4 ± 12.4 min and 36.6 ± 2.8 frequencies) (P ＜ 0.05).According to the Matta scoring criteria,the quality of pelvic reduction was evaluated as excellent in 21 cases,as good in 30 cases,as fair in 13 cases and as poor in one in the 3D printing group,yielding an excellent and good rate of 78.5％ while as excellent in 22 cases,as good in 36 cases,as fair in 12 cases and as poor in 2 cases in the conventional group,yielding an excellent and good rate of 80.6％.According to the Majeed scoring criteria,the curative effect was evaluated at the last follow-up as excellent in 27 cases,as good in 26 cases,as fair in 11 cases and poor in one in the 3D printing group,giving an excellent and good rate of 81.5％ while as excellent in 30 cases,as good in 28 cases,as fair in 13 cases and as poor in one in the conventional group,giving an excellent and good rate of 80.6％.There were no statistically significant differences between the 2 groups in reduction quality or curative effect (P ＞ 0.05).No nonunion or iatrogenic neurovascular lesions happened during the follow-up period.Conclusion 3D-printing modeling is helpful for a good reduction and minimally invasive fixation with hollow screws for unstable pelvic fractures by reducing operation time and intraoperative fluoroscopy.

Objective To investigate radiological characteristics of the posterior tibial plateau fracture and operative treatments for the fracture.Methods Thirty-one cases of posterior tibial plateau fracture treated between February 2009 and February 2014 were enrolled.There were 19 men and 12 women aged 24-72 years (mean,42.5 years).Injury arose from traffic accidents (13 cases),falls from a height (9 cases),fall on the ground (5 cases),and crash (4 cases).Type Ⅴ in 15 cases and type Ⅵ in 15 cases were classified by the Schatzker classification.Meanwhile,all fractures were identified as three-column pattern.According to the X-ray and CT manifestations of fracture displacement,the cases with minor displacement were grouped as Group A (22 cases) and the cases with major displacement group as Group B (9 cases).Depending on the radiographic characteristics of fracture size and angle off fracture line,anterior approach for reduction and fixation was performed in Group A and combined anterolateral and posteromedial approaches in Group B.Radiographic and functional outcomes were evaluated using the Rasmussen score.Results All cases underwent one-stage surgery uneventfully.Operation time was 80-120 minutes (mean,98 minutes) in group A and was 110-165 minutes (mean,110 minutes) in Group B.Mean total operation time was 105 minutes.Period of follow-up was 6-48 months (mean,21.5 months).Rasmussen radiographic results showed total excellent to good rate of 84％ with 86％ in Group A and 78％ in Group B respectively.Rasmussen functional results showed total excellent to good rate of 87％ with 91％ in Group A and 78％ in Group B respectively.Conclusions Anterior approach or anterolateral approach combined with posteromedial approach for reduction and internal fixation is developed according the radiographic findings and degree of fracture displacement.Clinical outcome is good and associated intraarticular soft tissue injury can be managed concurrently.

Objective To investigate the possibility,surgical methods,outcome and surgical indications of minimal invasion dynamic hip plate (MIDHP) through percutaneous limited open reduction in treatment of subtrochanteric femur fractures.Methods All cases underwent percutaneous limited open reduction with MIDHP.Duration of operation,intraoperative bleeding volume,length of incision,incidence of intra-or post-operative complications of all case were recorded.X-ray films were reviewed periodically after operation to analyze aspects of fracture displacement,loosening of intemal fixation,screw cutting femoral neck,screw penetrating out of or withdrawing from femoral head,bending or breaking of internal fixation,and fracture healing.Hip joint function was evaluated according to Huang' s criteria.Results Operation lasted for 45-55 minutes (average 50 minutes),showing the incision length of 4.0-5.0 cm (average 4.5 cm) and blood loss of 50-200 ml (average 150 ml).A total of 21 cases were enrolled in the study and were followed up for 6-28 months (average 18 months).In the follow-up,loosening or bending of internal fixation,fracture displacement,screw cut-out,and screw penetrating or withdrawing from femoral head did not occur.In the meantime,incision,bone,and joint were not infected.All cases had bony fusion within 3 months with the fracture healing rate of 100％.According to Huang' s criteria,hip function was excellent in 19 cases and good in two.Conclusions MIDHP with percutaneous limited open reduction is characterized by less trauma,small incision,less blood loss,less postoperative complications,firm fixation,early functional exercise,free load,and good hip functional recovery and hence is suitable for cases of different subtrochanteric femur fractures,especially for cases combined with osteoporosis.

Objective To investigate the injury and disruption of anterior sacroiliac ligament (ASIL) and sacrotuberous/sacrospinous ligament complex(STL/SSL),as well as the displacement of pubic symphysis (PS) and sacroiliac joint (SIJ),associated with anterior-posterior compression (APC) of Young-Burgess type Ⅱ.Methods Test models of APC of Young-Burgess type Ⅱ were created in 10 fresh human pelvic cadaveric specimens which were randomized into 2 equal groups (n =5).The fight hemipelvis in one group was fixed to a table (the limited group) while that in the other was not (the unlimited group).At the disruption point of ASIL during external rotation of the hemipelvis,displacement of PS,separation distance between the anterior parts of the sacroiliac joint,and injury and disruption of STL/SSL were recorded.When STL/SSL was gradually made to breakdown and fracture with continuous external rotation of the hemipelvis,bony changes and injuries to the posterior pelvic ligaments were observed and recorded.Results At the failure point of ASIL,the mean displacement of PS was 23.8 ± 2.8 mm and that of SIJ was 10.9 ± 4.4 mm,showing no significant difference between the limited and unlimited groups (P ＞ 0.05);the mean external rotation angle was 40.1°± 9.8° and the mean torsion was 646.7 ± 131.5 N,showing significant differences between the limited and unlimited groups (P ＜ 0.05).At the disruption point of ASIL,obvious injuries or disruption of STL/SSL were not observed in the unlimited group but observed in the limited group.With extreme external rotation,obvious disruption of STL/SSL was not found in the unlimited group but observed in the limited group.When ASIL and STL/SSL were all fractured,the mean displacement of PS was 41.8 mm and that of SIJ was 16.8 mm in the limited group.Conclusions Since APC injury can lead to 2 situations,limited or unlimited hemipelvis,external rotation injuries to the ligaments differ in the 2 different situations.When ASIL fails,the displacement of PS will fluctuate greatly.

Objective To evaluate application of Steinmenn pins to assist reduction in the treatment of unstable intertrochanteric fractures with proximal femoral nail antirotation(PFNA).Methods From February 2010 to June 2013,38 unstable intertrochanteric fractures were treated by us.There were 23 men and 15 women,aged from 32 to 69 years.By Evans-Jensen classification,18 cases were type Ⅲ,13 type Ⅳ and 7 type Ⅴ.They were divided into 2 groups (n =19).Group A received reduction on a traction bed assisted by Steinmenn pins plus PFNA fixation while group B received reduction only on a traction bed plus PFNA fixation.The 2 groups were compared in terms of fracture reduction,operation time,intro-operative blood loss,fracture healing time,and Harris scores one year postoperation.Results According to the evaluation system modified by Baumgaetner et al.,the postoperative quality of fracture reduction was fine in 15 cases and fair in 4 in group A while it was fine in 9 cases,fair in 8 and poor in 2 in group B,showing a significant difference between the 2 groups (P ＜ 0.05).The operation time in group A (50.7 ± 11.9 min) was significantly shorter than in group B (63.4 ± 15.1 min),and the hip joint Harris score (89.4 ±4.4) one year after operation for group A was significantly higher than that for group B (79.6 ±6.4) (P ＜ 0.05).There were no significant differences between the 2 groups regarding intraoperative blood loss,fracture heeling time and follow-up time (P ＞ 0.05).No cases of refracture,delayed union,nonunion,or avascular necrosis of the femoral head were reported.Conclusion In the treatment of unstable intertrochanteric fractures,compared with reduction only on a traction bed plus PFNA fixation,application of Steinmenn pins to assist reduction on a traction bed plus PFNA fixation may lead to better curative efficacy due to its limited invasion,simplicity and beneficial assistance in reduction.

Objective:To investigate whether the Garden indexes can serve as a criterion for rotational displacement of femoral neck fracture.Methods:Ten cadaveric specimens of healthy human proximal femur were used for this study. They came from 3 males and 2 females who had died at the age from 45 to 70 years old. A Kirschner wire of 2.0 mm in diameter was implanted into the center of the femoral head. Osteotomy was conducted perpendicular to the middle line of the femoral neck. The rotational angles were marked on the distal osteotomy surface. Each cadaveric specimen was rotated sequentially at pronation and supination angles of 0°, 10°, 20°, 30°, 40°, 50°, 70° and 90°, respectively. X-ray images of anterior-posterior and lateral views were taken to record all the rotations of the specimens. Picture Archiving and Communication Systems (PACS) were used to measure the Garden indexes and compare them among anterior-posterior and lateral X-ray films of different pronation and supination angles. Changes in the area of the femoral head fovea at different rotation angles were observed as well.Results:There were no significant differences in the auterior-posterior or latera Garden indexes from 0° to pronation or supination 30°, with all the Garden values >155° ( P>0.05); from pronation of 40° to pronation of 90°, the Garden indexes were 152.36°±1.41°, 146.04°±1.64°, 143.95°±0.60° and 141.73°±0.60° for anterior-posterior views and 172.54°±0.86°, 168.57°±0.98°, 157.18°±1.17° and 156.47°±1.63° for lateral views, showing a significant difference between rotational angles ( P<0.05); from supination of 40° to supination of 90°, the Garden indexes were 151.67°±1.06°, 147.32°±1.82°, 142.77°±0.75° and 139.88°±1.48° for anterior-posterior views and 172.28°±0.79°, 166.76°±1.02°, 155.67°±1.74° and 154.16°±1.27° for lateral views, showing a significant difference between rotational angles ( P<0.05). The area of the femoral head fovea decreased gradually with the increase in pronation angle, and increased gradually with the increase in supination angle. Conclusions:The Garden indexes cannot serve as an accurate indication of rotational displacement in reduction of femoral neck fracture when the pronation or supination angles ranges from 0° to 30°. Changes in the area of the femoral head fovea can help determine the rotational displacement of the femoral neck fracture.

Based on Ag nanoparticles as the surface-enhanced Raman spectroscopy (SERS)-active nanostructure, the SERS of uric acid was presented in the paper. The absorption spectroscopies of uric acid and the mixture of silver colloids and uric acid were measured. The possible enhancing mechanism of the uric acid on silver colloid was speculated. The characteristic SERS bands of uric acid were tentatively assigned. The influence of absorption time and different ion on the SERS of uric acid were also discussed. The SERS spectral intensity changes linearly with the uric acid concentration, which indicated that the SERS might provide a new kind of direct and fast detecting method for the detection of uric acid. The detection limit of uric acid in silver sol is found to be 1 mg/L.
Metal Nanoparticles ; chemistry ; Silver ; chemistry ; Spectrum Analysis, Raman ; methods ; Surface Properties ; Uric Acid ; analysis