Yanguo Qin

A functional chitosan-based hydrogel as a wound dressing and drug delivery system in the treatment of wound healing

Functional active wound dressings are expected to provide a moist wound environment, offer protection from secondary infections, remove wound exudate and accelerate tissue regeneration, as well as to improve the efficiency of wound healing. Chitosan-based hydrogels are considered as ideal materials for enhancing wound healing owing to their biodegradable, biocompatible, non-toxic, antimicrobial, biologically adhesive, biological activity and hemostatic effects. Chitosan-based hydrogels have been demonstrated to promote wound healing at different wound healing stages, and also can alleviate the factors against wound healing (such as excessive inflammatory and chronic wound infection). The unique biological properties of a chitosan-based hydrogel enable it to serve as both a wound dressing and as a drug delivery system (DDS) to deliver antibacterial agents, growth factors, stem cells and so on, which could further accelerate wound healing. For various kinds of wounds, chitosan-based hydrogels are able to promote the effectiveness of wound healing by modifying or combining with other polymers, and carrying different types of active substances. In this review, we will take a close look at the application of chitosan-based hydrogels in wound dressings and DDS to enhance wound healing.

Gene silencing of NOB1 by lentivirus suppresses growth and migration of human osteosarcoma cells

NIN1/RPN12 binding protein 1 homolog (Saccharomyces cerevisiae) (NOB1) encodes a chaperone protein that joins the 20S proteasome with the 19S regulatory particle in the nucleus and facilitates the biogenesis of the 26S proteasome, which plays a role in maintaining cellular homeostasis by controlling protein degradation. In order to investigate the role of NOB1 in osteosarcoma, NOB1 protein expression in human osteosarcoma cell lines was assessed using western blot analysis. Lentivirus-mediated short hairpin RNA was employed to knock down NOB1, and the effects of NOB1 silencing on cell growth were assessed using MTT, colony formation and cell cycle assays. Cell migration was observed using the Transwell assay. In addition, the expression levels of E-cadherin and β-catenin were examined by western blot analysis. Functional analysis indicated that NOB1-knockdown markedly inhibited cell growth and caused G2/M-phase arrest in human osteosarcoma cells. Furthermore, NOB1 inhibition decreased cell migration and increased E-cadherin and β-catenin expression in U2OS cells. In conclusion, the present study suggested that NOB1 depletion may inhibit osteosarcoma development by increasing E-cadherin and β-catenin expression and, for the first time, indicated the potential of NOB1 as a target in osteosarcoma treatment.

Novel exploration of 3D printed wrist arthroplasty to solve the severe and complicated bone defect of wrist

Purpose Although proximal row carpectomy, wrist arthrodesis and even total wrist arthroplasty were developed to treat wrist disease using bone and cartilage of the wrist, severe and complicated bone defects caused by ferocious trauma and bone tumors remain a stubborn problem for surgeons. Development and application of the three-dimensional (3D) printing technology may provide possible solutions. Design/methodology/approach Computed tomography (CT) data of three cases with severe bone defects caused by either trauma or bone tumor were collected and converted into three-dimensional models. Prostheses were designed individually according to the residual anatomical structure of the wrist based on the models. Both the models and prostheses were produced using 3D printing technology. A preoperative design was prepared according to the models and prostheses. Then arthroplasty was performed after preoperative simulation with printed models and prostheses. Findings The diameter of the stem and radial medullary cavity, the direction and location of the prosthesis, and other components were checked during the preoperative design and simulation process phases. The three cases with 3D printed wrist all regained reconstruction of normal anatomy and part of the function after surgery. The average increasing Cooney score rate of Cases 2 and 3 was 133.34 ± 23.57 per cent, and that of Case 1 reached 85 per cent. The average declining rate of the Gartland and Werley Score in Cases 2 and 3 was 65.21 ± 18.89 per cent, and that of Case 1 dropped to 5 per cent in the last follow-up. The scores indicated that patients experienced pain relief and function regain. In addition, the degree of patient satisfaction improved. Originality/value 3D printed wrist arthroplasty may provide an effective method for severe and complicated cases without sacrificing other bones. Personal customization can offer better anatomy and function than arthrodesis or other traditional surgical techniques.

Acetate templating on calibrated standing digital radiograph improves accuracy of preoperative templating for total hip arthroplasty

BACKGROUND The accuracy of preoperative templating with respect to leg length, femoral offset, and the size of femoral and acetabular components is essential to the success of total hip arthroplasty (THA). Traditionally, templating has been performed using printed film with acetate templates. However, preoperative templating designed by different prosthetic manufacturers cannot be used directly on the film due to varying acetate template amplification ratios. Computer-based templating needs specialized digital templating software, which has cost implications. To address these shortcomings, we bring forward several questions: (1) the accuracy of traditional manual templating combined with the calibrated digital radiograph for preoperative templating, (2) the inter- and intraobserver reliability of this method. HYPOTHESIS Using calibrated digital radiograph with traditional manual templating improves the accuracy and reproducibility of preoperative templating for THA. PATIENTS AND METHODS We designed a stepwise method that combines the traditional manual templating with standing digital radiograph calibrated by a scaling ball. Two separate observers (XJL, QYG) analyzed data of 82 patients (109 THAs) who had undergone THA with preoperative templating using the calibrated digital templating. The intra- and interobserver reliability was assessed by intraclass correlation coefficient. RESULTS The size of the acetate template acetabular based on our method was identical to the actual implanted acetabular size in 55.0% (XJL 110/218 [50.5%]; QYG 130/218 [59.6%]) of the cases indicating moderate accuracy. The intraclass correlation coefficient (ICC) for acetabular templating indicated almost perfect interobserver (ICC=0.918 [95% CI, 0.893-0.937]) and intraobserver agreement (ICC=0.932 [95% CI, 0.912-0.947]). While the exact implanted femoral size was predicted in 55.3% (XJL 122/218 [56.0%]; QYG 119/218 [54.6%]) of the cases. The ICC for femoral component templating indicated almost perfect interobserver (ICC=0.944 [95% CI, 0.927-0.957]) and intraobserver agreement (ICC=0.909 [95% CI, 0.883-0.930]). DISCUSSION This new stepwise method may prove to be a more reliable preoperative design choice to accurately calibrate magnification with radiograph, and could solve the incompatibility of the preoperative template designed by different prosthetic companies for direct use with the x-ray film. The method described is practical, convenient, cost-effective and does not require specialized equipment or software, thus making it particularly suitable for use in underdeveloped settings. LEVEL OF EVIDENCE Level IV, case series without controls.

Customized Knee Prosthesis in Treatment of Giant Cell Tumors of the Proximal Tibia: Application of 3-Dimensional Printing Technology in Surgical Design

Background We explored the application of 3-dimensional (3D) printing technology in treating giant cell tumors (GCT) of the proximal tibia. A tibia block was designed and produced through 3D printing technology. We expected that this 3D-printed block would fill the bone defect after en-bloc resection. Importantly, the block, combined with a standard knee joint prosthesis, provided attachments for collateral ligaments of the knee, which can maintain knee stability. Material/Methods A computed tomography (CT) scan was taken of both knee joints in 4 patients with GCT of the proximal tibia. We developed a novel technique – the real-size 3D-printed proximal tibia model – to design preoperative treatment plans. Hence, with the application of 3D printing technology, a customized proximal tibia block could be designed for each patient individually, which fixed the bone defect, combined with standard knee prosthesis. Results In all 4 cases, the 3D-printed block fitted the bone defect precisely. The motion range of the affected knee was 90 degrees on average, and the soft tissue balance and stability of the knee were good. After an average 7-month follow-up, the MSTS score was 19 on average. No sign of prosthesis fracture, loosening, or other relevant complications were detected. Conclusions This technique can be used to treat GCT of the proximal tibia when it is hard to achieve soft tissue balance after tumor resection. 3D printing technology simplified the design and manufacturing progress of custom-made orthopedic medical instruments. This new surgical technique could be much more widely applied because of 3D printing technology.

Cross-sectional Anatomy of Ilium for Guiding Acetabular Component Placement Using High Hip Center Technique in Asian Population.

Background:Many clinical studies have been published involving the use of a high hip center (HHC), achieved good follow-up. However, there is a little anatomic guidance in the literature regarding the amount of bone stock available for initial implant coverage in this area of the ilium. The purpose of this study was to evaluate the thickness and width of the human ilium and related acetabular cup coverage for guiding acetabular component placement in HHC. Methods:A total of 120 normal hips in 60 cases of adult patients from lower extremities computer tomographic angiography Digital Imaging and Communications in Medicine data were chosen for the study. After importing the data to the mimics software, we chose the cross sections every 5-mm increments from the rotational center of the hip to the cephalic of the ilium according the body sagittal axis, then we measured the thickness and width of the ilium for each cross section in axial plane, calculated the cup coverage at each chosen section. Results:At the acetabular dome, the mean thickness and width of the ilium were 49.71 ± 4.88 mm and 38.92 ± 3.67 mm, respectively, whereas at 1 cm above the dome, decreased to 41.35 ± 5.13 and 31.13 ± 3.37 respectively, and 2 cm above the dome, decreased to 31.25 ± 4.04 and 26.65 ± 3.43, respectively. Acetabular cup averaged coverage for 40-, 50-, and 60-mm hemispheric shells, was 100%, 89%, and 44% at the acetabular dome, 100%, 43.7%, and 27.5% for 1 cm above the dome, and 37.5%, 21.9%, and 14.2% for 2 cm above the dome. Conclusions:HHC reconstructions within 1 cm above the acetabular dome will be an acceptable and smaller diameter prosthesis would be better.

Three-dimensional reconstruction method for measuring the knee valgus angle of the femur in northern Chinese adults.

The purpose of this study was to establish a method for measuring the knee valgus angle from the anatomical and mechanical axes on three-dimensional reconstruction imaging models, and to use this method for estimating an average knee valgus angle value for northern Chinese adults. Computed tomographic angiography data in DICOM format for 128 normal femurs from 64 adult subjects were chosen for analysis. After the femur images were subjected to three-dimensional reconstruction, the deepest point in the intercondylar notch (point A), the midpoint of the medullary cavity 20 cm above the knee-joint line (point B), and the landmark of the femoral head rotation center (point C) were identified on each three-dimensional model. The knee valgus angle was defined as the angle enclosed by the distal femoral anatomical axis (line AB) and the femoral mechanical axis (line AC). The average (mean±SD) of knee valgus angle for the 128 femurs was 6.20°±1.20° (range, 3.05° to 10.64°). Significant positive correlations were found between the knee valgus angles of the right and left sides and between the knee valgus angle and age. During total knee arthroplasty, choosing a valgus cut angle of approximately 6° may achieve a good result in reestablishing the natural mechanical alignment of the lower extremity for patients of northern Chinese ethnicity. Larger valgus cut angles should be chosen for older patients.概要研究目的利用三维重建影像模型获取膝外翻角, 并通过使用这种方法来测量中国北方成人膝外翻角的平均估计值。创新要点本研究所获取的膝外翻角平均值对于在中国北方人群进行膝关节置换术时有着重要的参考意义, 新的三维重建测量法使得膝外翻角的术前个体化测量更加精确。研究方法利用64 名患者的CT 血管造影(CTA)的DICOM数据获取共128 件股骨三维重建模型。 在重建的股骨模型上分别定位髁间凹最高点(点A)、 膝关节线上20 cm 截面的髓腔中点(点B)和股骨头旋转中心(点C)。 之后膝关节外翻角即由股骨远端解剖轴(线AB)与股骨机械轴(线AC)所围成(上述定位过程详见图5)。 经统计分析后, 128 件股骨的平均外翻角值为6.20°±1.20°。 统计分析还发现, 膝外翻角与个体年龄呈显著性正相关, 同一个体的左右侧外翻角呈显著性正相关。重要结论在对北方成年人群进行膝关节置换术时, 选取外翻角为6°可会在重建人体下肢力线上获得更好的术后效果。 在对年长患者进行手术时应选用更大的外翻角。

Heat treatment effect on the mechanical properties, roughness and bone ingrowth capacity of 3D printing porous titanium alloy

The weak mechanical strength and biological inertia of Ti–6Al–4V porous titanium alloy limit its clinical application in the field of orthopedics. The present study investigated the influence of different solution temperatures (e.g. 800 °C, 950 °C and 1000 °C) on the mechanical properties, roughness and bone ingrowth capacity of Ti–6Al–4V porous titanium alloy prepared by Electron Beam Melting. It was found that the compressive and shear strength were promoted with the increase of solution temperature because of the transformed crystallinity of Ti–6Al–4V titanium alloy and phase changes from TiAl to TiAl + TiV. In addition, the topological morphology, surface roughness and wettability of the porous titanium alloy scaffolds were improved after heat treatment, and in turn, the adhesion rate and cell proliferation of bone marrow mesenchymal stem cells were enhanced. Compared with the scaffolds before and after heat treatment at 800 °C, the scaffolds heat-treated at 950 °C and 1000 °C achieved better bone ingrowth, extracellular matrix deposition and osseointegration. These findings indicate the great potential of heat treatment in possessing Ti–6Al–4V porous titanium alloy for orthopedic implant.

Correcting pelvic obliquity in the lateral position to improve acetabular component orientation during total hip arthroplasty

BACKGROUND The acetabular component orientation during total hip arthroplasty (THA) impacts future hip function and early revision. Correcting pelvic obliquity may improve outcomes. OBJECTIVE To correct pelvic obliquity in the lateral position by applying a gradienter and plumb during THA using fluoroscopy. METHODS Fifty patients undergoing THA were randomized and divided into 2 groups. In controls, acetabular components were placed using traditional methods. In experimental patients, acetabular components were placed after correcting pelvic obliquity. We measured pelvic obliquity and recorded intra-operative and post-operative abduction angles, comparing abduction angle bias between post-operative measurements and intra-operation estimations. RESULTS Before correction, the average pelvic obliquity was -1.647∘± 4.512∘ in experimental patients. The average abduction angle in experimental patients was 42.685∘± 3.355∘ postoperatively, differing by 1.962∘± 1.515∘ from intra-operative estimates, while in control patients, it was 44.534∘± 4.844∘ postoperatively, differing by 4.244∘± 3.042∘ from intra-operative estimates. The bias of the abduction angle was much greater in control than in experimental patients (P< 0.05). CONCLUSION The pelvic obliquity in the lateral position affects surgeon judgment during THA. By correcting pelvic obliquity with a gradienter and plumb, the abduction angle bias can be reduced.

A rare case report: enlarged iliopsoas cystic solid mass associated with femoral head necrosis induced by heavy alcohol consumption

Rationale: This article presents an unusual case of a large iliopsoas cystic solid mass associated with femoral head necrosis in a patient with heavy alcohol consumption for years. Patient concerns: The patient reported pain and limitation of movement at the right hip for 4 months. A soft tissue mass can be palpated deep in the groin several days after the onset of pain. Diagnoses: The laboratory assessments indicated an inflammatory response of the patient. Imaging was performed on the femoral head and iliopsoas cyst. The pathological feature of the mass was evaluated through biopsy examination. It was found that iliopsoas cystic solid mass is secondary to the femoral head necrosis induced by heavy alcohol consumption. Interventions: The patient underwent elective total hip arthroplasty. The bursa was excised and the anterior hip capsule closure was performed. Outcomes: After the surgery, imaging results showed a well-positioned prosthesis. At 1-year follow-up, the prosthesis was still well-positioned and no signs of recurrence of iliopsoas bursa were found. Lessons: We suggested the performance of elective total hip arthroplasty, bursa excision, and closure of the anterior hip capsule in patients with femoral necrosis and iliopsoas bursitis presented simultaneously.