Combination of Clavicular Hook Plate with Coracoacromial Ligament Transposition in Treatment of Acromioclavicular Joint Dislocation.

OBJECTIVE: To evaluate the clinical efficacy of Arbeitsgemeinschaft für Osteosynthesefragen (AO) clavicular hook plate (CHP) combined with coracoacromial ligament transposition for Rockwood III-V dislocation of AC joint, providing an alternative choice for AC joint dislocation treatment. METHODS: Twenty-five patients diagnosed with Rockwood III-V dislocation of acromioclavicular (AC) joint, including 18 males and seven females, aged 43.5 ± 2.4 years old on average, who had undergone open reduction and AO CHP in combination with coracoacromial (CC) ligament transposition between January 2010 and December 2015, were retrospectively analyzed. Among them, 17 cases were diagnosed as type III, five cases were type IV, and three cases were type V. The surgery mainly included three main steps: bone flap incision, drilling in the clavicle, and hook plate fixation and AC joint reposition. The treatment efficacy was evaluated through clinical examinations and imaging studies for the shoulder joint, including gross observation and measuring coracoid clavicle distance (CC-Dist) using orthophoria X-ray before and 1 year after the surgery, and University of California (UCLA) shoulder rating scale. RESULTS: All the patients were followed up three to four times in 18 months (12-24 months) on average, and the UCLA rating results showed that there were 17 excellent cases (68%), five good cases (20%), and three fair cases (12%). The CC-Dist values after the surgery reduced to 9.7 ± 0.7 mm, which was significantly (P < 0.05) lower compared to that before the surgery (15.8 ± 1.6 mm). Most (88%) of the cases showed almost normal joint function and good anatomical arrangement of the acromioclavicular joint, without any secondary dislocation, and for them, 12 ± 2 weeks on average were needed to regain the normal function of shoulder joint movement. CONCLUSION: Due to the stable fixation, fewer complications, and satisfactory therapeutic effect with great clinical value, the combination of AO CHP and CC ligament transposition is expected to be used for treating Rockwood III-V dislocation of AC joint.

Effects of intramedullary nailing fixation on quality of life and joint function in patients with femoral neck fractures.

OBJECTIVE: This study intended to investigate the changes in quality of life and joint function after intramedullary nailing fixation in patients with femoral neck fractures. METHODS: A total of 38 patients with femoral neck fractures received surgical treatment from February 2016 to November 2018 were enrolled as study subjects, and were divided into the intramedullary nailing group (IIN group, n=13) and the plate fixation group (PO group, n=25). The efficacy, general surgical indices, postoperative complications, hip function scores and imaging results were compared between the two groups. RESULTS: The response rate of the IIN group was 100.00%, significantly higher than 72.00% of the PO group (P<0.05). The length of hospital stay, blood loss, and the length of the healing period in the IIN group were lower than those in the PO group (P<0.05). The incidence of infection, deformity, loosening of internal fixation, and failed internal fixation in the PO group were significantly higher those than in the INN group (P<0.05). At 3, 6, and 12 months after surgery, the INN group had higher Harris scores and SF-36 scores than the PO group (P<0.05). The response rates of Harris scores of patients in the IIN group were significantly higher than those in the PO group at 12 months postoperatively (P<0.05). CONCLUSION: Intramedullary nailing fixation in patients with femoral neck fractures has the advantages of a shorter time in bed and better functional recovery, lower incidence of complications and higher long-term joint function with better quality of life.

Evaluation of the application value of a three-dimensional digital model of the knee in clinical practice.

OBJECTIVE: To compare the knee shape and bone parameters between knee prosthesis products from overseas companies and a Chinese patient's knee, and to apply the anatomical basis for Chinese knee prosthesis design. METHODS: Three-dimensional digital models were built, including prosthesis products for a normal adult. The relevant anatomy index was measured, and physical parameter, radiographic, geometric, knee kinematic, and distal geometry data were collected on the femur and tibia. RESULTS: The width of the femoral condyle (WFC), width of the medial femoral condyle (WMFC), width of the lateral femoral condyle (WLFC), depth of the intercondylar fossa (DICF), sagittal length of the medial femoral condyle (SLMFC), sagittal length of the lateral femoral condyle (SLLFC), angle of the medial femoral condyle (AMFC), and angle of the lateral femoral condyle (ALFC) in the femur and the transverse diameter (ML) and anteroposterior diameter (AP) of the tibial bone were measured. These parameters were significantly lower in the normal group compared with the prosthesis product model group. CONCLUSION: When using an imported knee prosthesis, the osteotomy angle may not fit perfectly. Use of an imported prosthesis may be an important factor in the increasing failure of knee arthroplasty in China.

Precise Resection of Macrodactyly Under Assistance of Three-Dimensional Reconstruction Technology: A Case Report.

Macrodactyly of the foot is an extremely rare congenital malformation characterized by an increase in the size of all the elements or structures of a digit or digits. Most sources indicate that macrodactyly affects the hand more often than the foot. This rare medical condition usually requires surgical intervention with a precise preoperative plan and postoperative rehabilitation. We present a case of macrodactyly of the right foot in which surgical reduction of the foot under assistance of 3-dimensional image technology was performed with satisfying cosmetic and functional outcomes.

Strontium Ameliorates Glucocorticoid Inhibition of Osteogenesis Via the ERK Signaling Pathway.

Glucocorticoid (GC) has been widely used in clinical work due to its anti-inflammatory and immune-inhibitory properties. However, long-term or high-dose administration is associated with side effects, such as GC-induced osteoporosis (GIOP), which causes great pain for and poses a heavy financial burden on patients. We sought to investigate the potential effects of strontium on GIOP and further explore its underlying mechanisms, including its reversal of the inhibitory effect of GC on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). We incubated BMSCs with Dexamethasone (DEX) in combination with or without strontium and then measured osteogenic and adipogenic gene expression levels by RT-qPCR and Western blot. We added a specific ERK signaling pathway inhibitor, U0126, to evaluate the involvement of that pathway. Strontium promoted osteogenic differentiation and matrix mineralization in DEX-treated BMSCs, accompanied by upregulation of RUNX2, Osx, ALP, BSP, COL1A1, and OCN. DEX blocked the expression of several osteogenesis-related marker genes by activating the ERK signaling pathway. U0126 attenuated the suppression of osteogenesis in DEX-treated BMSCs. These results suggested that strontium could enhance osteogenic differentiation and matrix mineralization by counteracting DEX's inhibitory effect on osteogenesis via the ERK signaling pathway. Therefore, strontium might be a promising therapeutic agent for GIOP.

A finite element analysis of two internal fixation methods for unstable femoral neck fractures in young adults / 中华创伤骨科杂志

Objective:To compare internal fixation with 3 cannulated screws versus with an anteromedial support plate plus 3 cannulated screws using finite element analysis for unstable femoral neck fractures (Pauwels type Ⅲ).Methods:Recruited for this study was a 34-year-old male volunteer with a height of 173 cm and a weight of 75 kg. Continuous thin-layer helical CT was conducted to scan the segment from his hip joint to the middle shaft of his tibia. Digital medical software was used to establish three-dimensional models of the femur based on his femoral CT data. The digital femoral necks were dissected as necessary to simulate femoral neck fractures of Pauwels type Ⅲ. The fractures were fixated with 3 ordinary cannulated screws in a mode of inverted triangle (screw group) and with 3 ordinary cannulated screws in a mode of inverted triangle plus an anteromedial steel plate (screw-plate group). After the 2 groups of models were subjected to identical constraints and 3 kinds of load (slow walking, twisting and standing on one leg), they were compared in terms of distribution of Von Mises stress and deformation.Results:Under various loads in both groups, the maximum deformation occurred in the femoral head. In the condition of slow walking, the deformation in the screw-plate group was 1.97 mm, which was smaller than that in the screw group (2.26 mm). In the conditions of twisting and standing on one leg, similar deformations were observed in both groups. Under all kinds of load, the maximum stress occurred in the middle part of the bottom screw and the fracture line in all the models. In the screw group, the peak stresses were 318.09 MPa, 92.11 MPa and 147.21 MPa for conditions of slow walking, twisting and standing on one leg, greater than those in the screw-plate group (229.86 MPa, 86.94 MPa and 124.48 MPa).Conclusions:The cannulated screws plus an anteromedial support plate are a recommendable fixation method for young adults with unstable femoral neck fracture, because they can effectively share the stress on the cannulated screws, lead to better mechanical stability of the fracture ends than the fixation with merely 3 cannulated screws and effectively prevent shortening of the femoral neck.

Application of custom anatomy-based nerve conduits on rabbit sciatic nerve defects: in vitro and in vivo evaluations.

The intermingling of regenerated nerve fibers inside nerve grafts is the main reason for mismatched nerve fibers. This is one of the key factors affecting limb function recovery after nerve injury. Previous research has shown that the accuracy of axon regeneration can be improved by a bionic structural implant. To this aim, iodine and freeze-drying high-resolution micro-computed tomography was performed to visualize the 3D topography of the New Zealand rabbit sciatic nerve (25 mm). A series of 1-, 2-, 3-, and 4-custom anatomy-based nerve conduits (CANCs) were fabricated based on the anatomical structure of the nerve fascicle. The match index, luminal surface, and mechanical properties of CANCs were evaluated before implanting in a 10-mm gap of the sciatic nerve. Recovery was evaluated by histomorphometric analyses, electrophysiological study, gastrocnemius muscle weight recovery ratio, and behavioral assessments at 12 and 24 weeks postoperatively. The accuracy of nerve regeneration was determined by changes in fluorescence-labeled profile number during simultaneous retrograde tracing. Our results showed that the optimal preprocessing condition for high-resolution micro-computed tomography visualization was treatment of the sciatic nerve with 40% Lugol's solution for 3 days followed by lyophilization for 2 days. In vitro experiments demonstrated that the match index was highest in the 3-CANC group, followed by the 2-, 1-, and 4-CANC groups. The luminal surface was lowest in the 1-CANC group. Mechanical properties (transverse compressive and bending properties) were higher in the 3- and 4-CANC groups than in the 1-CANC group. In vivo experiments demonstrated that the recovery (morphology of regenerated fibers, compound muscle action potential, gastrocnemius muscle weight recovery ratio, pain-related autotomy behaviors, and range of motion) in the 3-CANC group was superior to the other CANC groups, and achieved the same therapeutic effect as the autograft. The simultaneous retrograde tracing results showed that the percentages of double-labeled profiles of the 2-, 3-, and 4-CANC groups were comparatively lower than that of the 1-CANC group, which indicates that regenerated nerve fascicles were less intermingled in the 2-, 3-, and 4-CANC groups. These findings demonstrate that the visualization of the rabbit sciatic nerve can be achieved by iodine and freeze-drying high-resolution micro-computed tomography, and that this method can be used to design CANCs with different channels that are based on the anatomical structure of the nerve. Compared with the 1-CANC, 3-CANC had a higher match index and luminal surface, and improved the accuracy of nerve regeneration by limiting the intermingling of the regenerated fascicles. All procedures were approved by the Animal Care and Use Committee, Xinjiang Medical University, China on April 4, 2017 (ethics approval No. IACUC20170315-02).

Role of the HDAC6/STAT3 pathway in regulating PD-L1 expression in osteosarcoma cell lines.

Histone deacetylases (HDACs), initially described as histone modifiers, have more recently been verified to target various other proteins unrelated to the chromatin environment. On this basis, findings of the current study demonstrates that the pharmacological or genetic abrogation of HDAC6 in osteosarcoma cell lines down-regulates the expression of program death receptor ligand-1 (PD-L1), an important co-stimulatory molecule expressed in cancer cells, which activates the inhibitory regulatory pathway PD-1 in T cells. As shown by our results, the mechanism by which HDAC6 regulated PD-L1 expression was mediated by the transcription factor STAT3. In addition, we observed that selective HDAC6 inhibitors could inhibit tumor progression in vivo. Crucially, these results provide an essential pre-clinical rationale and justification for the necessity of further research on HDAC6 inhibitors as potential immuno-modulatory agents in osteosarcoma.

Overcoming cisplatin resistance in osteosarcoma through the miR-199a-modulated inhibition of HIF-1α.

Dysregulation of miRNAs has been shown to contribute to multiple tumorigenic processes, as well as to correlate with tumour progression and prognosis. miR-199a has been shown to be dysregulated in multiple tumour types. However, the association between miR-199a and the chemoresistance features of osteosarcoma are not well understood, the target genes for miR-199a and the regulatory mechanisms are also unknown. In the present study, we demonstrated that miR-199a is expressed at low levels in osteosarcoma cells and patient samples. By the selection and establishment of cisplatin resistant osteosarcoma cell line, we observed a correlation between miR-199a and cisplatin resistance in osteosarcoma cells: resistant cells exhibit attenuated miR-199a expressions and exogenous overexpression of miR-199a sensitizes osteosarcoma cells to cisplatin. Moreover, we identified HIF-1α as a direct target for miR-199a. Intriguingly, cisplatin resistant osteosarcoma cells display significantly elevated HIF-1α expression under hypoxia. We report here overexpression of miR-199a resensitizes cisplatin resistant cells to cisplatin through inhibition of HIF-1α in vitro and in vivo. Finally, by analysing the clinical osteosarcoma patient samples, we demonstrate a reverse correlation between miR-199a and HIF-1α mRNAs. Our study will provide mechanisms for the miRNA-mediated anticancer therapy and miR-199a may be considered a promising therapeutic agent for osteosarcoma patients who fail to respond to conventional chemotherapy.

Outcomes of post-traumatic tibial osteomyelitis treated with an Orthofix LRS versus an Ilizarov external fixator.

OBJECTIVE: To compare the therapeutic effects of the Orthofix limb reconstruction system (LRS) versus the Ilizarov external fixator on osteomyelitis of a tibial bone defect. MATERIALS AND METHODS: Among 153 patients hospitalized for bone lengthening therapy from January 1, 1996 to January 1, 2015, 129 patients were selected for a retrospective analysis. Forty-three of the candidate patients were treated using the Orthofix LRS and the other 86 were treated using an Ilizarov external fixator. The average follow-up was 96 months. We evaluated the patients at follow-up visits, and compared the length of time the patients wore the fixation devices. We also examined the scores of Activities of Daily Living (ADL) tests and a Self-rated Anxiety Scale (SAS), the range of motion, and the incidence of pin track infections. RESULTS: The results indicated that both approaches were effective for treating the bone defect. Compared with the patients who wore an Ilizarov fixator for the treatment of post-traumatic osteomyelitis, those who wore an Orthofix LRS tended to be more satisfied with their quality of life and the outcome after the operation. CONCLUSION: Although both approaches were effective for treating the bone defect, the overall patient outcomes were superior for the Orthofix LRS, suggesting that it should be considered as the first option in the treatment of traumatic osteomyelitis of the tibial diaphysis.

NRSN2 promotes osteosarcoma cell proliferation and growth through PI3K/Akt/MTOR and Wnt/ß-catenin signaling.

Osteosarcoma is the most common bone cancer in children and adults. However, its pathogenesis, especially molecular mechanisms remain elusive. In current study, we screened GEO Database and found a poorly studied protein Neurensin-2 (NRSN2), which is highly expressed in osteosarcoma tissues. Neurensin-2 (NRSN2) is a small neuronal membrane protein and localized in small vesicles in neural cells, previous study found that it has been implicated in hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC). We here report that the expression of NRSN2 is more commonlyelevated in 18 fresh osteosarcoma tissues. Furthermore, both loss- and gain-functions assays revealed that NRSN2 could promote osteosarcoma cell proliferation and growth both in vitro and in vivo. In addition, we further found that those effects on osteosarcoma by NRSN2 are associated with the dysregulated PI3K/AKT/mTOR signaling and Wnt/ß-catenin signaling. In conclusion, our study found a novel oncogenic protein, NRSN2, which promotes osteosarcoma cell proliferation and as a membrane protein, NRSN2 also could be a potential treatment target for osteosarcoma.

Bone defects following post-traumatic tibial osteomyelitis treated by bone transportation with Orthofix versus Ilizarov external fixation / 中华创伤骨科杂志

Objective To compare the curative effects of Orthofix extended external fixator versus Ilizarov external fixator in the treatment of bone defects following post-traumatic tibial osteomyelitis.Methods During the period from January,1996 through January,2015,129 patients were selected for a retrospective analysis.They were 106 males and 23 females,aged from 14 to 60 years (average,36.5 years).Orthofix extended external fixator was used in 43 of them and Ilizarov external fixator in 86.Bone transportation started 7 to 10 dlays after surgery at a speed of 1 mm/d and was completed in 4 turns.The 2 groups were compared in terms of mineralization time for the extended bone,hone lengthening length,fixation time,union indexes,Activity of Daily Living Scale (ADL),Self-Rating Anxiety Scale (SAS),knee range of motion (ROM) and complications.Results The patients were followed up for 13 to 216 months (average,96 months).Orthofix group and llizarov group were not significantly different in mineralization time for the extended bone,bone lengthening length,fixation time or union indexes (P ＞ 0.05).In Orthofix group and Ilizarov group respectively,there were 6 versus 73 patients with mildly limited self-living abilities and 37 versus 13 patients with little limited self-living abilities by ADL scores;there were 33 versus 16 cases of mild anxiety,8 versus 63 cases of moderate anxiety and 2 versus 7 cases of grave anxiety by SAS scores;there were 39 versus 10 cases of limited knee ROM of 15° to 30° and 4 versus 76 cases of limited knee ROM of 30° to 60°.There were significant differences between the 2 groups in the above indexes (P ＜ 0.05).The rate of complications in Orthofix treatment group(79.1％,34/43) was significantly lower than in Ilizarov group (88.4％,76/86) (P ＜ 0.05).Conclusions In the treatment of bone defects following post-traumatic tibial osteomyelitis,the curative effects of Orthofix extended external fixator are similar to those of Ilizarov external fixator.However,they may have different effects on the life and psychology of the patients in the long run.Therefore,specific therapeutic scheme should be decided in consideration of the advantages of the 2 treatments as well as the conditions of specific patients.

[Effect of patellar non-resurfacing on clinical results after total knee arthroplasty/].

OBJECTIVE: To evaluate the influence of patellar non-resurfacing on the effectiveness after total knee arthroplasty (TKA). METHODS: Between April 2008 and April 2011, 163 patients with degenerative osteoarthritis of the knee underwent TKA without patellar resurfacing, and the clinical data were retrospectively analyzed. There were 65 males and 98 females, with a mean age of 63 years (range, 54-78 years). According to Outerbridge classification for cartilage degeneration, 22 cases were classified as grade I, 38 cases as grade II, 64 cases as grade III, and 39 cases as grade IV. There was no significant difference in gender, age, and sides among patients at 4 grades (P > 0.05). The intraoperative tourniquet-using time and postoperative complications were recorded; the knee society score (KSS), patella score (PS), patients' satisfaction, and anterior knee pain [using visual analogue scale (VAS)] were used to evaluate the knee function. X-ray films were routinely taken to observe the position of the prosthesis and the patella. RESULTS: The mean tourniquet-using time was 125 minutes (range, 90-150 minutes). All incisions obtained healing by first intention, and no early postoperative complication occurred. All patients were followed up 2-5 years (mean, 3.6 years). The KSS and PS scores were significantly improved at 6 months and last follow-up when compared with preoperative scores (P < 0.05), but no significant difference between at 6 months and last follow-up (P > 0.05). Significant differences in KSS and PS scores were found among patients with different grades of cartilage degeneration at preoperation (P < 0.05), but no significant difference at last follow-up (P > 0.05). At last follow-up, 7 patients experienced anterior knee pain (mild pain in 5, moderate pain in 2). The results of satisfaction were very satisfied in 90 cases, satisfied in 66 cases, not certain in 5 cases, and not satisfied in 2 cases. No significant difference was found in satisfaction and anterior knee pain among patients with different grades of cartilage degeneration (P > 0.05). CONCLUSION: Patellar non-resurfacing has no effect on the effectiveness after TKA.