Magnesium and its alloys have been widely studied in the field of orthopaedics for their desirable mechanical properties, biodegradability and biocompatibility. However, the rapid degradation rate of magnesium and its alloys cannot match the healing process of bone itself, and may adversely affect the adhesion, growth and differentiation of surrounding cells, resulting in early loosening of implants, thus limiting their wide clinical application. Surface coating modification is a feasible and promising anti-corrosion solution to solve the problem of uncontrollable corrosion rate of magnesium implants. The surface coating modification technology can optimize the integration of the bone-implant interface by improving the bone induction ability of the implant surface (such as the bio-mimetic coating based on phosphate ceramics) or improving the corrosion resistance (such as the micro-arc oxidation coating with wear resistance and corrosion resistance, and the phytic acid coating with self-healing potential). While optimizing the degradation rate of magnesium implant, it can also realize multiple functions such as promoting osseointegration, drug delivery and photothermal therapy through composite component modification. In this paper, the advantages and disadvantages of different coating modification method on the surface of orthopaedic magnesium implants are comprehensively illustrated, and the key technologies in each preparation process are summarized and the composite modification methods are further discussed, so as to provide references for the preparation of multifunctional magnesium implants that meet the requirements of orthopaedic applications.

Osteoporosis is a common disease of old age that affects millions of people worldwide. Besides, it has been a chronic disease difficult to treat in the elderly, so it is of great significance to develop new drugs for the treatment of senile osteoporosis. The endocannabinoid system contains cannabinoid ligands, endocannabinoid receptors, and enzymes required for the synthesis and degradation of endocannabinoids, which play an important role in bone metabolism. Preclinical studies using endocannabinoid system-based therapies in animal models and in vitro have shown that endocannabinoid systems can prevent senile osteoporosis and highlight their therapeutic potential for senile osteoporosis. In this paper, PubMed, ScienceDirect, CNKY, and Wanfang databases were searched for articles related to the endocannabinoid system and osteoporosis. This paper analyzed the pathogenesis of senile osteoporosis (such as calcium, active vitamin D3 deficiency or insufficiency, sex hormone deficiency, cell function decline and secondary to chronic diseases, etc.), and reviewed the various components of the endocannabinoid system and their application in osteoporosis by regulating bone homeostasis in recent years, providing a new direction for the clinical treatment of senile osteoporosis.

Polyetherketoneketone (PEKK) is a semi-crystalline linear thermoplastic polymer with two ketone bonds and one ether bond in the main chain structure. It has many advantages such as elastic modulus close to that of natural human bone, biocompatibility, good chemical stability, radiolucency, compatibility with MRI, etc, which make it a new biomaterial for the production of orthopedic implants. The development of PEKK composites with better bone bioactivity without compromising the original properties of PEKK through special material preparation processes has become a hotspot. PEKK composites are made by combining biological ceramics (hydroxyapatite, silicon nitride) and metals with good biocompatibility (aluminum, tantalum and titanium). These composites not only retain the elastic modulus similar to that of human bone, but also improve hardness, biocompatibility, antibacterial properties, and bone integration ability, and thus have great potential in the field of orthopedic implants. The application of PEKK and its composites in the orthopedic field was searched in PubMed, Embase, ScienceDirect, CNKI and Wanfang databases. The properties advantages and disadvantages of PEKK and its composite materials modified by various methods in the recnt years (e.g. modification doping mixture, modification of the surface by sulfonation, 3D printing and treatment by surface deposition) were analyzed to provide a reference for the preparation clinically usable orthopedic implants with different functions.

Objective:To investigate the effect of arthroscopic superior capsular reconstruction (ASCR) of irreparable massive rotator cuff tears (RCTs) using the "Sandwich" patch graft (autologous fascia lata + LARS artificial ligament + autologous fascia lata).Methods:The patients with irreparable massive RCTs who underwent ASCR by using "Sandwich" patch graft were retrospectively evaluated between December 2016 and October 2018. All cases were followed up more than two years. The pain and function of the shoulder were evaluated by visual analogue scale (VAS), active forward elevation (aFE), American Shoulder & Elbow Surgeons score (ASES), University of California Los Angeles (UCLA) score, and Constant-Murley score. The acromiohumeral distance (AHD) and patch healing were assessed by shoulder X-ray and MRI scan.Results:Twenty-nine patients (12 males and 17 females) were enrolled for final analysis. The average age was 66.0±5.88 years (range 55-77 years). The average length of follow-up was 35.3±7.20 months (range 24-46 months). The tendon of the subscapularis muscle was intacted in 13 cases and repairable in 16 cases. All patients' teres minor muscles were intact and the function of deltoid muscles was all complete. Based on Hamada classification of massive RCTs, 11 cases with type 2, 14 cases with type 3, and 4 cases with type 4. At the last follow-up visit, the AFE of the surgical shoulder was 158.45°±23.87° (range 70°-180°), which was significantly higher than before the surgery 92.59°±45.99° (range 20°-160°, t=6.190, P<0.001). The ASES score was 92.92±9.08 (range 64-100), UCLA score was 31.62±3.93 (range 19-35), and Constant-Murley score was 85.8±8.44 (range 68-94), which were higher than those before the operation 30.69±12.99 (range 68-95), 10.93±3.43 (range 4-17), 39.62±12.68 (range 14-55). There were significant differences between them, respectively ( t=21.145, P<0.001; t=21.348, P<0.001; t=16.333, P<0.001). The VAS was 0.41±0.57 (range 0-2 points), which was significantly lower than that of 4.90±1.05 (range 3-7 points) before operation ( t=20.267, P<0.001). At the last follow-up visit, MRI showed that the AHD increased from 3.31±1.57 mm (range 1.1-6.6 mm) to 6.94±1.76 mm (range 3.0-10.8 mm) significantly ( t=12.195, P<0.001). Radiological outcomes were evaluated according to MRI, the total healing rate was 89.7% (26/29). There were two cases of complete tears, which including one case of infection and 1 partial tears. Conclusion:ASCR of irreparable massive RCTs using "Sandwich" patch graft showed the high healing rate in the short-term follow-up, which is possible to restore the shoulder functions early. It is an effective method for the treatment of irreparable massive RCTs.

Objective: To investigate the clinical outcomes of arthroscopic bridging reconstruction of irreparable massive rotator cuff tears using autogenous fascia lata. Methods: From July 2015 to July 2017, a total of 10 cases (4 male and 6 female) who were treated with arthroscopic bridging reconstruction for irreparable massive rotator cuff tears using autogenous fascia lata were retrospectively analyzed. The age before surgery was 61.3±2.9 years (range 57-67 years). There were 7 patients with right shoulders and 3 with left shoulders. The dominate sides were involved in 7 cases. The trauma history was documented in 2 shoulders. The duration of preoperative symptoms was 14.0±13.5 months (1-48 months). The case with revision surgery was not included. The patients were examined with magnetic resonance imaging (MRI) to evaluate the healing of fascia lata patch bridging in the joint at one week, six months, one year and two years after operation. The motion range of shoulder and the clinical scores, including visual analogue scale (VAS), University of California Los Angeles (UCLA) score, Constant-Murley score and American Shoulder & Elbow Surgeons (ASES) score, were measured before surgery and at follow-up duration. Results: All cases were reconstructed the horizontal couple. No perioperative complication was occurred and all surgery were completed safely and successfully. At the end of two years, the score of ASES was 92.2±3.5 (range 88.3-98.3), UCLA 31.6±2.0 (range 28-34), Constant-Murley 85.2±5.4 (range 78-93) with significant difference (t=11.254, P=0.000; t=12.111, P=0.000; t=8.948, P=0.00) comparing with that before surgery. The VAS pain score was 0.6±0.5 (range 0-1) which was significantly lower than that preoperatively (t=11.326, P=0.000). At 2 years after operation, MRI shows that fascia lata patches healed well in 9 patients. However, one case was with re-tear and patch absorption. The range of motion of shoulder was significantly improved in all patients but with different degrees of weakness (3-4). Conclusion Arthroscopic bridging reconstruction using autogenous fascia lata could effectively improve shoulder function in patients with irreparable massive rotator cuff tears. The autogenous fascia lata patch can heal with the help of rotator cuff tissue through bridging reconstruction.

Objective To evaluate the accuracy of cone?beam breast CT (CBBCT) on tumor sizing in patients with invasive breast carcinoma and analyze the influence factors. Methods The preoperative CBBCT images of 82 female patients (85 breast lesions) with invasive breast carcinoma confirmed by pathology from November, 2011 to December, 2017 in Tianjin Medical University Cancer Hospital were included in this retrospective study. All the patients underwent the pathology and immunohistochemical test after operation. Tumor size estimation were performed on preoperative CBBCT images. Referring to tumor size measurement on pathology, all the lesions were divided into two groups. Concordance was defined as the discrepancy in diameter less than 0.5 cm, and the discordance was more than 0.5 cm. Pathology examination was performed after resection, and estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2(HER?2) and Ki?67 result were recorded. All the lesions were classified into molecular subtype, including 14 Luminal A, 50 Luminal B, 11 HER?2?enriched and 10 triple?negative. Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to analyze the reliability of CBBCT on tumor sizing. CBBCT?pathology discordance was analyzed based on the clinical, histopathology and CBBCT features by using t test, Chi?square and Fisher exact test. ROC curve was used to analyze the cut?off value between tumor size and CBBCT?pathology discordance. Results The agreement between CBBCT (2.155 ± 0.799) cm and pathology (1.986 ± 0.933) cm measurement was on moderate degree based on the ICC value (ICC=0.781, P<0.01) and had positive correlation (r=0.803, P<0.01). CBBCT?pathology concordance was found in 71 lesions, and discordance in 14 lesions. The factors of family history, symptom, pathology type, molecular subtypes, histological grade, surrounding fat invasion, lymphatic invasion, axillary lymph node metastasis, HER?2 positive and Ki?67 high expression had no significant difference between two groups. ER or PR positive had significant difference, suggesting that the accuracy of evaluation on ER or PR negative lesions could be reduced. The cut?off value of ROC curve between tumor size and CBBCT?pathology discordance was 2.08 cm, and the area under curve was 0.70. In 85 lesions. 66 of 75 mass lesions and 5 of 10 non?mass lesions were consistent. The lesion type had significant difference between two groups (χ2=6.705, P=0.010), which suggested the CBBCT evaluation on non?mass could have discrepancy with pathology. Conclusion CBBCT has high accuracy on tumor size evaluation on invasive carcinoma. ER or PR negative, large lesions or non?tumor lesions should be alert to the impact of CBBCT?pathology discordance before surgery which may cause the alteration of surgical protocols.

Although the incidence of prosthesis joint infection(PJI) is low, it is one of more serious complications recognized by joint surgery because of the difficulty in diagnosis and treatment, so it is very important to diagnose PJI in time. Currently, clinical diagnostic techniques for PJI are immature, and each technique has certain limitations in terms of sensitivity or specificity of diagnosis. In general, the diagnosis of PJI relies mainly on clinical symptoms, laboratory tests and imaging examinations. The detection of pathogenic microorganisms is the basis of laboratory diagnosis and clinical treatment. The results of microbial susceptibility testing are also the main basis for the clinical application of sensitive antibiotics to treat PJI. However, the current positive rate of PJI pathogen culture is not high. In comparison, polymerase chain reaction(PCR) technology does not depend on the premise that unknown microorganisms can be cultured in vitro, and it is rapid and highly sensitive. Therefore, the use of genetic technology, especially PCR technology to diagnose PJI has become one of the current research hot spots. In order to understand the research and development of PCR diagnostic techniques for joint prosthesis infection in recent years, in this paper, the research progress of genetic technology is reviewed, especially PCR technology in the diagnosis of PJI.

Objective:To discuss the value of CT quantitative parameters in prediction of the invasiveness of pulmonary mixed ground glass nodules(mGGNs).Methods:CT images of 164 patients with pulmonary ground-glass nodules(mGGNs),enrolled in Tianjin Medi-cal University Cancer Institute and Hospital from January 2013 to September 2016,confirmed by surgical pathology were analyzed ret-rospectively.CT quantitative parameters including maximum diameter,largest diameter perpendicular to the maximum diameter,vol-ume on both pulmonary window and mediastinal window,mean CT value and TDR(tumor shadow disappear rate)were evaluated be-tween minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC) with ROC and Logistic regression analysis. Re-sults:Logistic regression analysis showed that the maximum diameter of the pulmonary window(OR=3.080,95% CI:1.135-8.355,P=0.027)and the maximum diameter of the mediastinal window(OR=5.881,95%CI:1.634-21.166,P=0.007)independently predicted the invasiveness of mGGNs;the corresponding values of area under the curve of the combination of two parameters were 0.855,with sen-sitivity of 77.61% and specificity of 86.67 %.The cut-off point to the corresponding value of the maximum diameter on pulmonary win-dow and mediastinal window was 1.902cm and 1.273cm,respectively.Conclusions:CT quantitative parameters are helpful in predict-ing the invasiveness of mGGNs.The maximum diameters on both pulmonary window and mediastinal window are independent predic-tors.

Objective To understand the situation of iodine deficiency disorders and iodine nutrition of children in Yunnan Province after the implementation of new standard of salt iodine,and provide the basic data for prevention and control of iodine deficiency disorders.Methods Using multistage sampling method,Yunnan provincial evaluations for iodine deficiency disorders elimination were carried out.According to the comparative analysis of 2010 (pre-adjustment) and 2015 (post-adjustment) evaluation results,the changes of the median of salt iodine,the coverage rate of iodized salt,the qualified rate of iodized salt,the rate of qualified iodized salt consumption,goiter rate of school children aged 8-10 and the median of urinary iodine were evaluated.Salt iodine was tested using the "Salt Industry General Test Method for Determination of Iodine" (GB/T 13025.7-1999);thyroid volume examination of children using B-scan ultrasonography,thyroid volume calculation and enlargement judgment using "Diagnostic Criteria for Endemic Goiter" (WS 276-2007);and urinary iodine detection using "Urinary Iodine Arsenic Cerium Catalytic Spectrophotometry" (WS/T 107-2006).Results The medians of salt iodine in 2010 and 2015 were 30.6 and 22.4 mg/kg,respectively,the difference was statistically significant (U =317 503.50,P ＜ 0.01).The coverage rates of iodized salt in 2010 and 2015 were 99.6％ (1 681/1 688) and 98.9％ (2 592/2 622),the qualified rates of iodized salt were 98.6％ (1 657/1 681) and 89.7％ (2 325/2 592),and the rates of qualified iodized salt consumption were 98.2％ (1 657/1 688) and 88.7％ (2 325/2 622),and the differences were statistically significant (x2 =6.42,125.11,130.18,P ＜ 0.01);the rates of children goiter in 2010 and 2015 were 0.8％ (25/3 272) and 1.4％(44/3 245),respectively;the medians of urinary iodine of children were 289.0 and 157.3 μg/L,respectively,the difference was statistically significant (U =1 121 669.50,P ＜ 0.01).Conclusion After decreasing of salt iodine level starting from 2012 in Yunnan Province,the children iodine nutrition condition is in a more proper level.

Objective: To compare the diagnostic efficiency of lesion in dense breast between cone beam breast computer tomography (CBBCT) and mammography. Methods: From May 2012 to August 2014, 160 patients with 165 breasts who underwent mammography and CBBCT examinations were included in this study. The diagnostic results of CBBCT and mammography were reviewed and compared with pathological results. Results: In the 165 breast, 24 were dense breasts and 141 were dense breasts. The diagnostic results were similar in 109 lesions, but different in 56 lesions. According to the analysis of the 165 breasts using receiver operation characteristics (ROC) curve, the area under the ROC curves (AUC) of CBBCT and mammography were 0.923 (95%CI: 0.878-0.967, P<0.05) and 0.959 (95%CI: 0.926-0.992, P<0.05), respectively. With Breast Imaging-Reporting and Data System (BI-RADS) 4b as the critical value, the sensitivity and specificity were 70.0% and 98.7% using mammography, and 83.3% and 97.3% using CBBCT, respectively. The AUC of CBBCT and mammography of the 141 dense breasts was 0.919(95%CI: 0.868-0.969, P<0.05) and 0.973(95%CI: 0.947-0.999, P<0.05), respectively. With BI-RADS 4b as the critical value, the sensitivity and specificity were 69.0% and 98.6% by mammography, and 83.1% and 98.6% by CBBCT, respectively. Conclusions CBBCT showed higher sensitivity and specificity in the diagnosis of breast malignant tumors compared to mammography. It is expected to be applied to breast cancer detection in the future, especially in dense breast.