BACKGROUND: To solve the complications such as screw cut-out, loosening, and insufficient holding force that may occur during internal fixation of osteoporotic fractures, a new cement-reinforced screw combined with PHILOS plate is currently used to treat osteoporotic fracture of the proximal humerus. However, there are few reports on the clinical efficacy of this technique in the treatment of osteoporotic fractures of the proximal humerus in China. OBJECTIVE: To compare the clinical efficacy of a novel cement-reinforced screw combined with locking plate fixation and artificial humeral head replacement in the treatment of osteoporotic fractures of the proximal humerus. METHODS: Twenty-two patients with osteoporotic fractures of the proximal humerus admitted to at Guizhou Provincial People’s Hospital from February 2017 to March 2019 were enrolled, including 8 males and 14 females, aged 68-88 years. Ten patients underwent open reduction using new cement-reinforced screws combined with locking plate internal fixation (internal fixation group), and 12 patients underwent humeral head arthroplasty (humeral head arthroplasty group). The operation time, intraoperative blood loss, and intraoperative and postoperative complications were compared. The Visual Analogue Scale and Constant scores of the shoulder joint were detected at 6 months after surgery. All patients received a postoperative anti-osteoporosis treatment. The study was approved by the Ethics Committee of Guizhou Provincial People’s Hospital, approval No. 2017(02). RESULTS AND CONCLUSION: (1) Twenty-two patients were followed up for 6-15 months, an average of (9.0±1.6) months. (2) No toxicity reaction of bone cement or embolism occurred in both groups. One case of postoperative shoulder stiffness occurred in the internal fixation group. There were no complications in both groups, such as incision infection, heterotopic ossification, delayed healing, and screw cut-out. (3) The operation time and intraoperative blood loss in the internal fixation group were significantly less than those in the humeral head arthroplasty group (P < 0.05). (4) The Visual Analogue Scale and the excellent and good rate of Constant scores of the shoulder joint at 6 months after surgery showed no significant differences between two groups (P > 0.05). (5) In summary, the novel cement-reinforced screw technique combined with locking plate internal fixation has similar clinical efficacy with humeral head arthroplasty. Therefore, this new technique is an alternative internal fixation method for some patients scheduled for shoulder joint arthroplasty.

BACKGROUND: Our previous studies have found that silk fibroin-chitosan scaffold carrying bone marrow mesenchymal stem cells can repair cartilage defect in rabbits, but further exploration on the biocompatibility of tissue engineered cartilage is yet to be done. OBJECTIVE: To explore the biocompatibility of tissue engineered cartilage that is constructed in vitro by silk fibroin-chitosan scaffold with bone marrow mesenchymal stem cells. METHODS: Three-dimensional silk fibroin-chitosan scaffolds were prepared in a ratio of 1:1. Rabbit bone marrow mesenchymal stem cells were extracted, induced and seeded onto the silk fibroin-chitosan scaffold to construct the cell-scaffold composite. The composite was then implanted into a rabbit joint defect model for cartilage repair. There were three groups in the present study: Experiment group with implantation of induced bone marrow mesenchymal stem cells+silk fibroin-chitosan scaffold into the cartilage defect model, control group with implantation of silk fibroin-chitosan scaffold into the cartilage defect model, and blank group without implantation. RESULTS AND CONCLUSION: The three-dimensional silk fibroin-chitosan scaffolds were successfully prepared and combined with bone marrow mesenchymal stem cells (BMSCs) to construct the tissue engineered cartilage for repair cartilage defects in rabbits. Blood routine parameters, procalcitonin levels, erythrocyte sedimentation rates and C-reactive protein levels detected at 2, 4, 8, and 12 weeks post-implantation indicated no obvious signs of systemic infection, and there was no damage to liver and kidney functions in the three groups. There were also no significant differences between the three groups in terms of blood routines and liver and kidney functions (P > 0.05). As shown by gross observation, hematoxylin-eosin staining and scanning electron microscope, in the experimental group, cartilage defects were repaired, with scaffold degradation, no presence of inflammatory cells, and good integration with surrounding tissues. Therefore, tissue engineered cartilage constructed in vitro by silk fibroin-chitosan scaffolds carrying bone marrow mesenchymal stem cells has good biocompatibility, which provides an experimental basis for tissue engineering approaches to cartilage repair.

Objective To investigate the feasibility of restoration of cartilage defect with silk fibrin/chitosan(SF-CS)biological scaffold compound by induced bone marrow mesenchymal stem cells (BMSCs)in the elderly rabbits.Methods BMSCs were extracted,cultured and induced to differentiate,then inoculated into SF-CS three-dimensional scaffold restoration.54 rabbits(aged 16-18months)were divided into scaffold restoration,single scaffold and control groups(n=18 per group).The right knee joint was used for building cartilage defect model and implanted by scaffolds.General observation,tissue staining and modified Wakitani histological scoring were performed at 4,8 and 12weeks after operation.Results SF-CS scaffold was structured by multiple interlinked pores.The average pore size was 151.72 μm.The porosity was(92.72±4.78)％.The imbibition rate was (141.10± 6.87)％.BMSCs was grown well and proliferated dynamically in SF-CS scaffold after induction.At 12 weeks,the cartilage defect was basically repaired,type Ⅱ collagen was positively expressed and the scaffold was almost assimilated in scaffold restoration group.In single scaffold group,the cartilage defect was repaired mainly by fiber tissue,type Ⅱ collagen was less expressed and the scaffold almost degraded while the cartilage defect was repaired badly in control group.The scaffold restoration group was superior to single scaffold and control groups(P＜0.05)in improving the Wakitani score.Conclusions The SF-CS scaffold as BMSCs carrier may restore cartilage defect in knee joint of the elderly rabbits.

BACKGROUND:Silk fibroin/chitosan/nano hydroxyapatite (SF/CS/nHA) composite scaffold constructed in preliminary experiments has good physical and chemical properties.
OBJECTIVE:To study the capacity and mechanism of SF/CS/nHA composite scaffold for repair of rabbit radial bone defects.
METHODS:Thirty-six New Zealand white rabbits were selected to make animal models of right radial bone defects, and then randomly divided into SF/CS/nHA group, SF/CS group and blank control group. Blank control group had no treatment after modeling. X-ray radiography, gross observation and histopathological observation were performed at 4, 8, 12, 16 weeks postoperatively.
RESULTS AND CONCLUSION:Sixteen weeks after surgery, bone defects in the SF/CS/nHA group were completed replaced by normal bone tissue on X-ray images, and the bone marrow cavity showed complete recanalization with new bone formation;hematoxylin-eosin staining showed bone trabecula and many fusiform bone cells. In the SF/CS group, the bone mineral density in the defect area was slightly lower than that of the normal bone tissues, the bone marrow cavity was partly rehabilitated, and many chondrocytes were seen around bone cells that arranged irregularly with no bone trabecula or bone lamel a. In the blank control group, the images of bone calcification were consistent with normal bone tissues, and a closed bone ununion was formed at each end;hematoxylin-eosin staining showed that the blank control group was fil ed by fibrous connective tissue and a smal amount of bone-like tissues. SF/CS/nHA composite scaffold is better for repair of rabbit radial bone defects.

Objective To evaluate the clinical effects of the Masquelet technique combined with antibiotic calcium sulfate pellets in treating infected bone defects.Methods From February 2014 to February 2016,9 patients with infected bone defects were treated in our department,including 7 males and 2 females,with an average age of 37.0 years (range,24-56 years).6 cases were infected because of open fractures,3 infected after internal fixation operation.All defects were located in the lower limb diaphysis and metaphysis (3 cases in femur,6 cases in tibia).The length of the bone defects were 4-12 cm after debridement,all defects filled with PMMA loaded with Vancomycin,and fixed with exterual fixators.After 6-10 weeks,the bone cement spacers were taken out and the antibiotic calcium sulfate pellets were implanted into the membrane.A certain amount of autogenous cancellous bone granules would be mixed into the calcium sulfate pellets if the defect was larger than 6-8 cm.5 cases remained fixed with external fixators,3 cases replaced for plates,1 case replaced for plaster external fixator.Regular X-ray follow-ups were taken and complications recorded as well.Evaluate the healing of bone defect and functional recovery of adjacent joints by Samantha X score system,visual analogue scale (VAS) and Paley method,respectively.Results The 9 cases were followed up for a mean duration of 9.3 months (range,6-15 months).All bone defects healed after a mean time of 14 weeks (range,10-24 weeks).The wound poor healing occurred in only 1 case in the first stage of surgery,and cured by dressing changes.No complications of the recurrence of infection and implant failure.At the last follow-up,the average Samantha X score was 4.9,the VAS score was 0 to 3 (average 1.5) for patients standing on crutches and all the bone defect healing graded excellent evaluated by Paley method,the functional recovery of the adjacent joints graded:excellent in 6 cases,good in 2 cases,and fair in 1 case (the excellent and good rate was 89％).Conclusion Masquelet technique combined with antibiotic calcium sulfate particles is effective in the treatment of infected bone defects.

Osteoarthritis is one of the most common chronic diseases in orthopedics.With increasing populations of aging and obese people,its incidence has risen year by year and become a major public health problem.The hallmark of osteoarthritis is cartilage destruction,the main cause of which is degradation of extracellular matrix by catabolic enzymes and death of chondrocytes caused by apoptosis or autophagy.Articular cartilage is a hypoxic environment because it lacks blood supply and the joint cavity is relatively closed.A hypoxic environment induces chondrocytes to produce a series of hypoxia-related molecules which can regulate the expression of catabolic enzymes,autophagy and apoptosis of chondrocytes for osteoarthritis.This paper aims to review recent reports on the relationship between hypoxic-related molecules and pathogenesis of osteoarthritis and discuss the role of hypoxia-related molecules in the pathogenesis of osteoarthritis.

Objective To investigate the efficacy of suprapatellar versus infrapatellar approach in tibial intramedullary nail fixation for tibial fracture. Methods Clinical trials that evaluated suprapatellar approach and infrapatellar approach for tibia intramedullary nailing fixation were searched in PubMed, EMBASE, Cochrane Central Register of Controlled Trials ( CENTRAL ) , Chinese Biology Medicine ( CBM) , Wanfang, Weipu and CNKI databases. Methodological qualities of the included studies were assessed using the Cochrane Collaboration tool and Newcastle-Ottawa Scale. Sensitivity analyses were performed to determine whether overall results were reliable. Publication bias was detected using Begg's test and Egger's test. Lysholm score, reoperation rate, Hospital for Special Surgery ( HSS ) score, operation time, intraoperative blood loss and hospital stay were selected to evaluate the clinical effect of suprapatellar approach and infrapatellar approach in tibial intramedullary nail fixation for tibial fracture. Results Two randomized controlled trials and six case-controlled studies involving 787 patients were included in the analysis. Sensitivity analyses indicated that the results were statistically significant. No significant publication bias was detected by Begg's test or Egger's test. Our meta-analysis indicated that suprapatellar approach had significantly higher Lysholm score ( MD=1. 04, 95％CI 0. 82 -1. 26, P<0. 05, I2 =10. 5％) and HSS score ( MD =0. 97, 95％CI 0. 65 -1. 30, P <0. 05, I2 =0 ) than infrapatellar approach ( P <0. 05 ) . Additionally, there were no statistical differences between the two procedures in reoperation rate, operation time, intraoperative blood loss and hospital stay (P>0. 05). Conclusion Compared with infrapatellar approach, suprapatellar approach in intramedullary nail fixation for tibial fracture can better relieve the pain, keep stability and motion of the knee joint and promote function recovery of knee joint.

To investigate the differentiation of bone mesenchymal stem cells(BMSCs) into chon-drocytes by miRNA-206 and its mechanism in osteoarthritis(OA). Methods From January, 2017 to July, 2018, rat BMSCs were isolated, and their CD90 and CD45 were detected by flow cytometry. Transfection of miRNA-206 or miRNA-206 inhibitors into BMSCs using lentiviral vectors, dexamethasone induction for 14 d, then use alician blue staining and type II collagen immunostaining to detect chondrogenic differentiation. MTT assay was used to detect the proliferation of mesenchymal stem cells. Western blot analysis was used to detect the Aggrecan, Col II, Sox9 and Runx2 markers in chondroblast cells. The expression level of the marker gene of Sox9 mRNA in chondroblasts were detected by RT-PCR.OA rat models were treated with lentiviral vectors transfected with miRNA-206 or miRNA-206 inhibitors, and Aggrecan, Col II, Sox9, Runx2 which were the markers of chondrogenesis were detected by Western blot. Results The purity of isolated BMSCs was (80.7±3.9)%. BMSCs transfected with miRNA-206 could promote cell proliferation and increase chondrogenic differentiation. Western blot results showed that the expression of Aggre-can, Col II and Sox9 was increased in the miRNA-206 transfection group, and the expression of Runx2 was down-regulate. Meanwhile, RT-PCR results showed that miRNA-206 can up-regulate the expression of the chondroblast marker gene Sox9 mRNA in BMSCs.Compared with the OA group, miRNA-206 could increase the expression of Aggre-can, Col II and Sox9 signaling proteins in cartilage tissue (P＜0.05), and down-regulate the expression level of Runx2 (P＜0.05). Conclusion The miRNA-206 can positively regulate the differentiation of BMSCs into chondrocytes, increase the ability of cell proliferation, up-regulate the expression of Aggrecan, Col II and Sox9, and down-regulate Runx2.The miRNA-206 increase chondrogenic capacity in rat models of osteoarthritis.

Objective:To compare the clinical efficacy of minimally invasive anterior column screw placement assisted by orthopedic robot with anterior subcutaneous internal fixation (INFIX) in the treatment of unstable pelvic fracture.Methods:A retrospective cohort study was conducted to analyze 42 patients (25 males and 17 females; aged 16-68 years [(41.8±3.2)years] with unstable pelvic fracture admitted to Guizhou Provincial People′s Hospital from June 2018 to December 2021. Anterior column screw group ( n=22) received orthopedic robot-assisted anterior column screw fixation of anterior pelvic ring fracture, and INFIX group ( n=20) received subcutaneous INFIX of anterior pelvic ring fracture. Posterior pelvic ring injuries were treated with closed reduction and percutaneous sacroiliac screw internal fixation. The operation time of anterior pelvic ring fixation, intraoperative blood loss, intraoperative fluoroscopy times, off-bed activity time when the visual analogue scale (VAS) was<3 points during weight-bearing and fracture healing time were compared between the two groups. The quality of pelvic fracture reduction was assessed according to the Matta scoring criteria at 2 days after surgery. The Majeed functional score was used to assess the functional status at the last follow-up. Intraoperative and postoperative complications were observed in both groups. Results:All patients were followed up for 6-24 months [(11.3±0.5)months].The operation time of anterior pelvic ring fixation was (33.4±2.6)minutes in anterior column screw group and (30.2±2.9)minutes in INFIX group ( P>0.05). The intraoperative blood loss was (15.9±3.1)ml in anterior column screw group and (41.4±6.2)ml in INFIX group ( P<0.01). The intraoperative fluoroscopy times were 12.2±2.4 in anterior column screw group and 14.7±2.5 in INFIX group ( P>0.05). The off-bed activity time was (3.2±0.4) weeks in anterior column screw group and (6.6±1.2)weeks in INFIX group ( P<0.01). The fracture healing time was (12.7±1.4)weeks in anterior column screw group and (16.2±1.9) weeks in INFIX group ( P<0.01). According to Matta scoring criteria, the excellent and good rate of posterior pelvic ring reduction quality was 100% in both groups, while the excellent and good rate of the quality of anterior pelvic ring reduction was 100% (excellent in 16 patients and good in 6) in anterior column screw group compared with 90.0% (excellent in 11 patients, good in 7, and fair in 2) in INFIX group ( P<0.05). During the final follow-up, the excellent and good rate of Majeed functional score was 90.9% (excellent in 16 patients, good in 4 and fair in 2) in anterior column screw group, significantly different from 80.0% (excellent in 10 patients, good in 6 and fair in 4) in INFIX group ( P<0.05). During the operation, no important tissue injuries such as blood vessels, nerves or spermatic cord occurred in either group. In anterior column screw group, no postoperative complications such as infection, spermatic cord injury or implant breakage occurred; in INFIX group, there were 2 patients with incision fat liquefaction, 4 with lateral femoral cutaneous nerve symptoms and 1 with heterotopic ossification, without the occurrence of implant breakage. Conclusion:Compared with anterior subcutaneous INFIX, orthopedic robot-assisted anterior column screw internal fixation for the treatment of unstable pelvic fracture has advantages of less bleeding, earlier tambulation, faster fracture healing, better fracture reduction quality, more satisfied postoperative functional recovery, and fewer complications.