Erythemato-squamous diseases are a general designation of six common skin diseases, of which the differential diagnosis is a difficult problem in dermatology. This paper presents a new method based on virtual coding for qualitative variables and multinomial logistic regression penalized via elastic net. Considering the attributes of variables, a virtual coding is applied and contributes to avoid the irrationality of calculating nominal values directly. Multinomial logistic regression model penalized via elastic net is thence used to fit the correlation between the features and classification of diseases. At last, parameter estimations can be attained through coordinate descent. This method reached accuracy rate of 98.34%±0.0027% using 10-fold cross validation in the experiments. Our method attained equivalent accuracy rate compared to the results of other methods, but steps are simpler and stability is higher.
Polydimethylsiloxane (PDMS) and hydroxyapatite (HA) were combined in our laboratory to fabricate an elastic porous cell scaffold with pore-forming agent, and then the scaffold was used as culture media for rat bone marrow derived mesenchymal stem cells (rBMSCs). Different porous materials (square and circular in shape) were prepared by different pore-forming agents (NaCl or paraffin spheres) with adjustable porosity (62%-76%). The HA crystals grew on the wall of hole when the material was exposed to SBF solutions, showing its biocompatibility and ability to support the cells to attach on the materials.
In the present study, swine thighbone samples with different water contents were prepared through process of dehydration. The influence of water content on the biotribological behavior of the bone tissue was studied with nanoindentation test, reciprocating sliding test and impact wear test. It is shown that the water contents had significant influence on the mechanical properties and biotribological behavior of the swine thighbone samples. In this experiment condition, with decreasing water content, the hardness and elastic modulus of the swine thighbone samples increased, while the tribological properties significantly decreased. The viscoelasticity of bone tissue decreased with decreasing water content, which mainly resulted in different wear mechanisms of the bone tissue samples under applied loading.
ObjectiveTo investigate the mid-term effect of lateral placement of bone graft on shoulder joint degeneration after modified arthroscopic Latarjet surgery with elastic fixation for recurrent anterior shoulder dislocation with an anterior glenoid bone defect.MethodsAccording to the inclusion and exclusion criteria, 18 patients with recurrent anterior shoulder dislocation and anterior glenoid bone defect who received the modified arthroscopic Latarjet surgery with elastic fixation between January 2015 and November 2016 were enrolled in this study. There were 12 males and 6 females with an average age of 26.2 years (range, 19-37 years). The number of shoulder dislocation ranged from 4 to 30 times (mean, 8.8 times). The disease duration was 8-49 months (mean, 23.8 months). The mean anterior glenoid bone defect was 25.2% of the glenoid surface (range, 20%-29%). The mean preoperative Instability Severity Index Score (ISIS) was 7.6 (range, 7-10). According to Samilson-Prieto classification, the shoulder joint degeneration was rated as grade 0 in 13 cases, grade Ⅰ in 3 cases, and grade Ⅱ in 2 cases. Before and after operation, the visual analogue scale (VAS) score, American Society of Shoulder and Elbow Surgery (ASES) score, Walch-Duplay score, Rowe score, and shoulder mobility were used to evaluate the effectiveness. Imaging examination was performed to observe the shoulder joint degeneration, the position of the bone graft, and the postoperative shaping of the scapular glenoid.ResultsAll patients were followed up 55-62 months, with an average of 59.6 months. There was no neurovascular injuries, infections, fixation-related and bone graft-related complications. No re-dislocation and revision occurred. All patients returned to normal life, 17 of whom returned to sport. The VAS score was significantly decreased and ASES, Walch-Duplay, and Rowe scores were significantly improved at last follow-up (P<0.05). No significant difference was found in range of motion of forward flexion, abduction, lateral rotation at 90° abduction, internal rotation at 90° abduction, or lateral rotation at 0° between pre- and post-operation (P>0.05). Three-dimensional CT showed that the centers of all bone grafts were between 3∶30 and 4∶30 (right shoulder) or between 7∶40 and 8∶20 (left shoulder) and no bone grafts were positioned superiorly or inferiorly in the glenoid En-face view. All bone grafts were positioned lateral to the scapular glenoid with an average distance of 3.5 mm (range, 2.3-4.6 mm) in cross-sectional imaging by CT. Compared with the preoperative Samilson-Prieto classification results, all cases showed no progression of shoulder joint degeneration at 36, 48 months and last follow-up. All bone grafts remodeled to a steady state within 24 months after operation. The bone graft and glenoid finally remodeled analogous to the shape of the intact glenoid in the En-face view and became flush with the glenoid rim, remodeling to a curved shape congruent to the humeral head in cross-sectional imaging by CT. The shape of the remodeled glenoid at last follow-up was not significantly different from that at 24 months after operation.ConclusionThe lateral placement of the bone graft during modified arthroscopic Latarjet surgery with elastic fixation do not accelerate the imaging changes of shoulder joint degeneration.
Study of the mechanical properties of in vivo corneal materials is an important basis for further study of corneal physiological and pathological phenomena by means of finite element method. In this paper, the elastic coefficient (E) and viscous coefficient (η) of normal cornea and keratoconus under pulse pressure are calculated by using standard linear solid model with the data provided by corneal visualization scheimpflug technology. The results showed that there was a significant difference of E and η between normal cornea and keratoconus cornea (P < 0.05). Receiver operating characteristic curve analysis showed that the area under curve (AUC) for E, η and their combined indicators were 0.776, 0.895 and 0.948, respectively, which indicated that keratoconus could be predicted by E and η. The results of this study may provide a reference for the early diagnosis of keratoconus and avoid the occurrence of keratoconus after operation, so it has a certain clinical value.
ObjectiveTo investigate the effectiveness of closed reduction and internal fixation with elastic nails in treatment of Mason type Ⅱ radial head fracture in adults.MethodsA clinical data of 28 patients with Mason type Ⅱ radial head fractures between May 2013 and March 2017 was retrospectively analyzed. Thirteen patients were treated with closed reduction and internal fixation with elastic nails (trial group); 15 patients were treated with open reduction and internal fixation with Herbert screws (control group). There was no significant difference in gender, age, cause of injury, side of fracture, and the time from injury to operation between the two groups (P>0.05). The operation time, blood loss, and fluoroscopy times in the two groups were recorded and compared. Postoperative X-ray films were used to evaluate the bone healing, heterotopic ossification, and necrosis of radial head. The effectiveness was evaluated according to Mayo score criteria of the elbow at last follow-up. ResultsAll patients were followed up 12-30 months (mean, 21.9 months). The operation time and blood loss were significantly less in the trial group than in the control group (P<0.05), while the fluoroscopy times significantly increased in the trial group than in the control group (P<0.05). X-ray films showed that all fractures healed with the bone healing time of (2.85±0.69) months in the trial group and (3.35±0.88) months in the control group. There was no significant difference in bone healing time between the two groups (t=1.654, P=0.110). Heterotopic ossification occurred in 2 cases in the control group. At last follow-up, there was no significant difference in the Mayo scores between the trial group (90.6±5.3) and the control group (86.4±7.1) (t=1.750, P=0.092).ConclusionClosed reduction and internal fixation with elastic nails, as a minimally invasive technique, has advantages of short operation time and less bleeding in the treatment of Mason type Ⅱ radial head fracture.
ObjectiveTo explore the effectiveness difference between titanium elastic intramedullary nail internal fixation and bone plate internal fixation in the treatment of adult Galeazzi fracture.MethodsNinety-seven patients of Galeazzi fracture according with the selection criteria were divided into 2 groups by prospective cohort study, who were admitted between January 2012 and November 2015. In the patients, 59 were treated with open reduction and bone plate internal fixation (plate group), and 38 with titanium elastic intramedullary nail internal fixation (minimally invasive group). There was no significant difference in the gender, age, cause of injury, fracture site, type of fracture, and time from injury to operation between 2 groups (P>0.05). The operation time, intraoperative blood loss, fracture healing time, and complications were recorded and compared between 2 groups, and the forearm function was evaluated by Anderson score.ResultsAll the patients were followed up 12-23 months (mean, 17 months). The operation time, intraoperative blood loss, fracture healing time of minimally invasive group were significantly less than those in plate group (P<0.05). There were 1 case of fracture nonunion, 1 case of wound infection in plate group, and 1 case of nail tail slight infection in minimally invasive group, which were all cured after the corresponding treatment. The remaining patients had good fracture healing, and no vascular injury, internal fixation failure, deep infection, or other complications occurred. According to Anderson score at 12 months after operation, the forearm function results were excellent in 46 cases, good in 12 cases, and poor in 1 case, with an excellent and good rate of 98.3% in plate group; and the results were excellent in 26 cases, good in 11 cases, and poor in 1 case, with an excellent and good rate of 97.4% in minimally invasive group; showing no significant difference (χ2=0.10, P=0.75).ConclusionMinimally invasive fixation with titanium elastic nail has such advantages as small damage, quick recovery, no skin scarring, etc. As long as the correct indication is selected, minimally invasive titanium intramedullary nail internal fixation of Galeazzi fractures can also get good effectiveness.
ObjectiveTo evaluate the effectiveness of titanium elastic nails for severe displaced proximal humeral fractures in older children. MethodsBetween April 2009 and July 2012, 31 cases of severe displaced proximal humeral fractures were treated with closed or open reduction and fixation with 2 titanium elastic nails, and the clinical data were retrospectively analyzed. There were 23 boys and 8 girls, aged from 10 to 15 years (mean, 12.8 years). The causes of injury were sports injury (16 cases), traffic accident (11 cases), and falling from height (4 cases). The interval from injury to operation was 6 hours to 7 days (mean, 72 hours). According to Neer-Horwitz classification, 17 cases were rated as type III fracture and 14 cases as type IV fracture. There were 21 cases of metaphyseal fractures and 10 cases of epiphyseal fractures. ResultsSatisfactory reduction of fracture and stable fixation were obtained in all patients (closed reduction in 23 cases and open reduction in 8 cases). Primary healing was achieved in all incisions; no infection and neurovascular injury occurred. All patients were followed up 12-36 months with an average of 20 months. X-ray films showed that all fractures healed at 7-10 weeks (mean, 8 weeks). During follow-up, no disturbance of development or angulation deformity caused by premature physeal closure or bone bridge formation was observed. At last follow-up, the average Neer score of the shoulder was 95.7 (range, 83-100). The appearance and motion of the shoulder were normal. There was no significant difference in the upper extremity length between affected side and contralateral side[(67.68±2.56) cm vs. (67.61±2.54) cm; t=-1.867,P=0.072]. ConclusionTitanium elastic nails for severe displaced humeral fractures in older children is a safe and effective method with a low complication incidence.
【Abstract】 Objective To explore the midterm efficacy of superelastic cage implantation for the treatment of osteonecrosisof femoral head (ONFH). Methods From July 1996 to January 1998, 54 patients (75 hips) of ONFH were treatedwith superelastic cage and followed up. Among 54 patients, 5 patients were lost to follow up and 3 patients were dead of myocardialinfarction, renal failure and gastric cancer, respectively. Forty-six patients completed follow up including 32 males and14 females, aged from 21 to 61 with an average of 39 years old. Twenty-nine hips were classified as Ficat Stage Ⅱ and 36 as StageⅢ . Harris score was 58.20 ± 13.82. All patients were evaluated both cl inically and radiographically. Results Postoperatively,forty-six patients (65 hips) were followed up for 86 to 125 months with an average of 8 years and 8 months. Harris score was 80.78 ± 18.77. Twenty-nine hips were rated excellent, 21 good, 2 fair and 13 poor．A total of 76.9% of overall cl inical results were rated as good or excellent. Eight hips (12.3%) with the cage broken were turned to total hip replacement. Radiographicevaluation: 16 hips (24.6%) rated as grade Ⅰ , 34 (52.3%) grade Ⅱ and 15 (23.1%) grade Ⅲ . Conclusion Superelastic cage implantation is one of alternative treatments for ONFH at early and midterm stages. However, long-term follow-up is needed to know whether it is able to cure ONFH and whether cages will be broken as time passes by.
In order to establish the best procedure to store the femur samples from the biomechanical viewpoint, we compared the effects of different storage methods on the mechanical properties of mouse femurs. We obtained femurs surgically from twenty C57BL/6J female mice, 12 weeks old, and randomly divided them into 5 groups, i.e. fresh control group, 4% paraformaldehyde fixation group, 4℃ storage group, -20℃ storage group and -80℃ storage group, respectively, with five mice in each group. For the three low-temperature storage groups, each group was stored for 1 week, 2 months, 6 months at their respective temperatures. After rewarming, three-point bending test was performed to test the load and deflection changes. The results showed that both the elastic modulus and deflection decreased significantly in the 4% paraformaldehyde group. The maximum load and elastic modulus of the samples in the 4℃ group after one week storage was significantly reduced; The mechanical properties were close to the fresh control group in the -20℃ group stored for 2 months but the maximum load was also reduced after 6 months. However, mechanical properties, such as elastic load, maximum load and elastic modulus, were not changed obviously in the -80℃ storage group. Accordingly, -80℃ cryopreservation had little influence on the mechanical properties of bone tissues, which proved that the temperature -80℃ is a suitable one for long-term preservation.