[Clinical study on the incidence of femoral head posterior tilt angle in non-displaced femoral neck fractures].

OBJECTIVE: To investigate the occurrence of posterior femoral head tilt after clinical non-displaced femoral neck fracture, and to provide a reference basis for clinical surgery and improvement of disease prognosis. METHODS: Total of 165 patients with non-displaced femoral neck fractures of Garden typeⅠandⅡfrom January 2018 to June 2022 were selected as study subjects including 48 males and 117 females, with an average age of (71.5±8.5) years old ranging from 53 to 89, involving 97 cases of typeⅠand 68 of typeⅡ. On the patient's preoperative sagittal or axial CT film of the hip, the angle formed by the radius line of the femoral head and the midline of the femoral neck was used as the posterior tilt angle of the femoral head (α), and the posterior tilt femoral head angle was measured using the method proposed by Palm. The measured data were divided into 6 groups:α<0°, 0°<α< 5°, 5°≤α<10°, 10°≤α<15°, 15°≤α<20°, α≥20°, and the incidence of different ranges of posterior tilt angle was compared. The sex composition ratio of 165 patients were analyzed and compared, and the age of 65 was used as the cut-off point to compare the incidence of fractures between genders. Patients were divided into the posterior tilt <20° group for 135 cases and the posterior tilt ≥20°group for 30 cases according to the preoperative posterior tilt angle, the differences between two groups in terms of gender and age were analyzed. RESULTS: Among 165 patients with non-displaced femoral neck fractures, 143 cases with poaterior tilt of the femoral head occurred with an incidence of 86.7%. Posterior tilt 0°<α<5° accounted for 36 cases with an incidence of 21.8%;5°≤α<10° accounted for 40 cases with an incidence of 24.2%;10°≤α<15° accounted for 27 cases with an incidence of 16.4%;15°≤α<20° accounted for 10 cases with an incidence of 6.1%;posterior tilt angle α≥20° accounted for 30 cases, the incidence was 18.2%, of which the maximum posterior tilt angle was 42.7°. Statistical analysis showed that the percentage of fractures in the 165 patients selected for this study was significantly higher in female than in male, and that the female group was more likely to have fractures before the age of 65 years compared to the male group. However, gender, age and fracture subtypes (GardenⅠ, Ⅱ) were not influential factors for femoral neck fractures with a preoperative posterior femoral head tilt angle >20°(P>0.05). CONCLUSION: The incidence of femoral head posterior tile in non-displaced femoral neck fractures is relatively high, in which severe posterior tile occurs, and the femoral head posterior tile angle≥20° can reach 18.2%. In patients with closed reduction internal fixation, the fracture end needs to be repositioned as much as possible to reduce the risk of postoperative avascular necrosis of the femoral head. In order to prevent femoral neck fractures, special attention should be paid to anti-osteoporosis treatment for female. Preoperative assessment of posterior tilt is critical for patients of different ages, genders and fracture subtypes (GardenⅠ, Ⅱ).

[Research progress of caput femoris posterior tilt and its impact on prognosis in nondisplaced femoral neck fractures].

There are still many unresolved problems in the treatment and prognosis of nondisplaced femoral neck fractures, such as nonunion and avascular necrosis of the caput femoris .In order to reduce the risk of various complications after non-displaced femoral neck fractures, the caput femoris posterior tilt of femoral neck fractures and its impact on prognosis have attracted more and more attention. A large number of scholars' studies have found that when the posterior tilt exceeds 20°, the risk of internal fixation failure increases significantly. Based on this concept, we can choose to use primary artificial joint replacement instead of three-screw internal fixation according to the different posterior tilt angles of patients to reduce the incidence of postoperative complications. At the same time, our analysis found that comminution of the posterior segment of the femoral neck would lead to an increase in the posterior inclination angles. The purpose of this review was to investigate the relationship between caput femoris posterior tilt of femoral neck fractures and surgical outcome, and to introduce a new method for measuring caput femoris posterior tilt of the femoral neck.

[Finite element analysis of optimal selection of cannulated threaded screw for the prevention of femoral neck shortening after internal fixation for femoral neck fracture].

OBJECTIVE: To propose the an optimal screw placement scheme to prevent femoral neck shortening, finite element analysis was used to evaluate the biomechanical outcome of different numbers formed by full threaded screws at different positions in the treatment of femoral neck fractures of Pauwels type Ⅱ. METHODS: Recruited for this study was a 55-year-old female volunteer with a weight of 70 kg and a height of 165 cm. CT scan data of her right femur was collected. The models of femoral of Pauwels typeⅡ and fully threaded screw(FTS) and partially threaded screw(PTS) were constructed in three-dimensional modeling software. All these screw placement schemes were divided into eight groups simulated the inverted triangular configuration:three PTSs, an anterosuperior FTS and two PTSs, a posterosuperior FTS and two PTSs, an inferior FTS and two PTSs, an anterosuperior PTS and two FTSs, a posterosuperior PTS and two FTSs, an inferior PTS and two FTSs and three FTSs. All fracture internal fixation models were processed in finite element analysis software. Parameters of postoperative femoral neck length, displacement distribution and peak displacement of screws and VonMises stress distribution and peak stress of screws, the proximal femur and fracture section were collected. RESULTS: The maximum VonMises stress of screws was 239.71, 213.44, 199.37, 230.82, 201.63, 215.72, 185.65 and 192.64 MPa, respectively, which was concentrated in the inferior screw near the fracture line. The maximum Von Mises stress of the proximal femur was 269.48, 241.62, 249.43, 269.69, 271.60, 346.64, 236.97 and 439.62 MPa, respectively, which was concentrated in the inferior medial area of subtrochanteric femur. The maximum Von Mises stress of fracture section was 149.12, 143.04, 140.47, 139.63, 139.81, 130.07, 117.77 and 57.89 MPa, respectively, which was concentrated around the partially threaded screw channel instead of the fully threaded screw channel. The maximum displacement of screws was 5.52, 5.43, 5.32, 5.17, 5.05, 5.13, 5.28 and 5.04 mm, respectively, which was along the axis of the femoral neck, and the displacement distribution was concentrated on the tip of the screw. The length of postoperative femoral neck length was 74.69, 74.72, 74.70, 74.70, 74.72, 74.70, 74.72 and 74.74 mm, respectively. CONCLUSION: The placement of one anterosuperior partially threaded screw and two fully threaded screws with an inverted triangular distribution can not only meet the sliding compression effect to promote femoral neck healing and ensure the stability of the proximal femur, but also reduce the degree of postoperative femoral neck shortening and reduce the incidence of hip joint dysfunction. This study provides a new optimal screw placement solution for the treatment of femoral neck fractures.

LncRNA SNHG1 modulates adipogenic differentiation of BMSCs by promoting DNMT1 mediated Opg hypermethylation via interacting with PTBP1.

Recent evidence indicates that the abnormal differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) plays a pivotal role in the pathogenesis of osteoporosis. LncRNA SNHG1 has been found to be associated with the differentiation ability of BMSCs. In this study, we aimed to elucidate the role of lncRNA SNHG1 and its associated pathway on the differentiation of BMSCs in osteoporosis. Mice that underwent bilateral ovariectomy (OVX) were used as models of osteoporosis. Induced osteogenic or adipogenic differentiation was performed in mouse BMSCs. Compared to sham animals, lncRNA SNHG1 expression was upregulated in OVX mice. Also, the in vitro expression of SNHG1 was increased in adipogenic BMSCs but decreased in osteogenic BMSCs. Moreover, overexpression of SNHG1 enhanced the adipogenic capacity of BMSCs but inhibited their osteogenic capacity as determined by oil red O, alizarin red, and alkaline phosphatase staining, while silencing of SNHG1 led to the opposite results. LncRNA SNHG1 interacting with the RNA-binding polypyrimidine tract-binding protein 1 (PTBP1) promoted osteoprotegerin (Opg) methylation and suppressed Opg expression via mediating DNA methyltransferase (DNMT) 1. Furthermore, Opg was showed to regulate BMSC differentiation. Knockdown of SNHG1 decreased the expressions of adipogenic related genes but increased that of osteogenic related genes. However, the knockdown of Opg partially reversed those effects. In summary, lncRNA SNHG1 upregulated the expression of DNMT1 via interacting with PTBP1, resulting in Opg hypermethylation and decreased Opg expression, which in turn enhanced BMSC adipogenic differentiation and contributed to osteoporosis.

lncRNA SNHG1 induced by SP1 regulates bone remodeling and angiogenesis via sponging miR-181c-5p and modulating SFRP1/Wnt signaling pathway.

BACKGROUND: We aimed to investigate the functions and underlying mechanism of lncRNA SNHG1 in bone differentiation and angiogenesis in the development of osteoporosis. METHODS: The differential gene or proteins expressions were measured by qPCR or western blot assays, respectively. The targeted relationships among molecular were confirmed through luciferase reporter, RIP and ChIP assays, respectively. Alkaline phosphatase (ALP), alizarin red S (ARS) and TRAP staining were performed to measure the osteoblast/osteoclast differentiation of BMSCs. The viability, migration and angiogenesis in BM-EPCs were validated by CCK-8, clone formation, transwell and tube formation assays, respectively. Western blot and immunofluorescence detected the cytosolic/nuclear localization of ß-catenin. Ovariectomized (OVX) mice were established to confirm the findings in vitro. RESULTS: SNHG1 was enhanced and miR-181c-5p was decreased in serum and femoral tissue from OVX mice. SNHG1 directly inhibited miR-181c-5p to activate Wnt3a/ß-catenin signaling by upregulating SFRP1. In addition, knockdown of SNHG1 promoted the osteogenic differentiation of BMSCs by increasing miR-181c-5p. In contrast, SNHG1 overexpression advanced the osteoclast differentiation of BMSCs and inhibited the angiogenesis of BM-EPCs, whereas these effects were all reversed by miR-181c-5p overexpression. In vivo experiments indicated that SNHG1 silencing alleviated osteoporosis through stimulating osteoblastogenesis and inhibiting osteoclastogenesis by modulating miR-181c-5p. Importantly, SNHG1 could be induced by SP1 in BMSCs. CONCLUSIONS: Collectively, SP1-induced SNHG1 modulated SFRP1/Wnt/ß-catenin signaling pathway via sponging miR-181c-5p, thereby inhibiting osteoblast differentiation and angiogenesis while promoting osteoclast formation. Further, SNHG1 silence might provide a potential treatment for osteoporosis.

The Effect on the Fracture Healing following Femoral Neck Shortening after Osteoporotic Femoral Neck Fracture Treated with Internal Fixation: Finite Element Analysis.

OBJECTIVE: To evaluate the stress status of fracture site caused by femoral neck shortening and to analyze the stress of fracture site and the implants from the finite element point of view. METHODS: CT scan data of hip of a normal adult female were collected. Three-dimensional reconstruction MICs and related module function simulation was used to establish the postoperative shortening model of femoral neck fracture with Pauwels angle > 50°, which was treated with cannulated screws. The models were divided into four groups: normal femoral neck, shortening in 2.5 mm, shortening in 7.5 mm, and shortening in 12.5 mm. The finite element analysis software msc.nastran2012 was used, and the data of maximum stress and stress nephogram of fracture site and implants were carried out. RESULTS: From normal femoral neck to shortening in 12.5 mm of the femoral neck, the maximum tensile stress increased gradually in the fracture site above the cannulated screws while compressive stress decreased gradually in the fracture site below the cannulated screws, and the maximum stress of the cannulated screws increased gradually with obvious stress concentration at the screw holes in the fracture site, and the peak value of stress concentration was about 179 MPa. CONCLUSION: The biomechanical environment of the fracture site changed by femoral neck shortening. With the increasing of femoral neck shortening, the stress of the fracture site and implants would be uneven; then, the stability of fracture site would become worse, and the possibility of implant sliding or even breakage would be increased.

[Progress of parathyroid hormone regulating bone metabolism via different signaling pathways].

Parathyroid hormone is one kind of osteoanabolic agents widely used in clinic for osteoporosis. However, parathyroid hormone needs to be further optimized in the treatment of osteoporosis due to its two way regulatory effect of bone formation with low-dose intermittent treatmentand bone resorption with high-dosecontinuous treatment. Hence, based on the molecular mechanism of parathyroid hormone regulating bone metabolism, we conclude that parathyroid hormone regulates bone metabolism mainly through the following signaling pathways: (1) Gs/cAMP/PKA signaling pathway, whichis the main mechanism of parathyroid hormone regulating bone metabolism to lead to bone formation or bone resorption. (2) Gq/11/PLC/PKC signaling pathway, whose f_6_main function is to inhibit osteogenesis.(3)nonPLC/PKC signaling pathway, which is considered to playosteogenic effect, but whose specific content is not completely clear. (4) ß-arrestin signaling pathway, which can only induceosteogenesis without osteoclastic activation byreceptor desensitization and endocytosis. In this work, we will review the specific contents and functions of the four main signaling pathways activated by parathyroid hormoneto find more optimalosteoanabolic agents. Among them, SOST and Dickkopf-1 monoclonal antibodies are novel targeted drugs. Parathyroid hormone-related peptide that specifically activates the nonPLC/PKC signaling pathway or ß-arrestin signaling pathway is worthy of further development and application.

[Finite element optimization analysis of minimally invasive screw treatment for Sanders typeâ ¡calcaneal fracture].

OBJECTIVE: To explore biomechanical characteristics of minimally invasive different screw fixations in treating Sanders typeⅡcalcaneal fractures. METHODS: Dicom data of calcaneus by CT scan were input into Mimics 21.0 software and Ansys15.0 software to construct three-dimensional finite element digital model of calcaneus;this model was input into UG NX 10.0 software, and calcaneus was cut according to Sanders classification to establish Sanders typeⅡ calcaneus model with posterior articular surface collapse;then simulated minimally invasive screw internal fixation after calcaneal fracture:a screw from posterior articular surface was used to outside-in fix sustentaculum tali, other 4 screws were used to fix calcaneus by different methods through calcaneal tuberosity, and 4 different calcaneal models were obtained. Under the same conditions, 4 types of internal fixation models were loaded respectively, and nonlinear finite element analysis was performed to calculate the stress distribution of different internal fixation models. RESULTS: Under the same condition of loading, the model 3 had smaller displacement value, maximum calcaneus displacement value and maximum equivalent stress value of the screw than other three internal fixation models, and the stress was more dispersed. CONCLUSION: In minimally invasive screw internal fixation of calcaneus fracture, after 1 sustentaculum tali screw fixation, 2 screws crossed fix posterior articular surface from calcaneal tuberosity, 2 screws fix parallelly calcaneocuboid joint from calcaneal tuberosity are more suitable for biomechanical requirements, and could provide basic theory for clinical treatment.

[Preliminary development of guided template of middle and upper thoracic percutaneous vertebroplasty in thoracic pedicle approach due to three dimentional soft tissue print technique].

OBJECTIVE: To investigate the feasibility of a drill template for the placement of guided template of middle and upper thoracic percutaneous vertebroplasty in thoracic pedicle approach on digital design and 3D printing technology. METHODS: The preoperative CT images of 20 patients with thoracic fracture were collected retrospectively. With the 3D soft tissue printing technology, the data was reconstructed by 3D imaging reconstruction software to produce 1∶1 three dimensional soft tissue model. The pedicle screw channel and the digital template were designed by the 3-matic module of Mimics15.0 software. After guide template was printed by 3D printer and three dimensional template was fixed on the model, 2.0 mm Kirschner was placed and the accuracy of a drill template was observed by CT scans, bone cement was injected through the puncture tube and verified with images. The time of nail guide design, guide template production and cost were recorded. RESULTS: The effectiveness of three dimensional thoracic model and digital guided template of middle and upper thoracic percutaneous vertebroplasty of thoracic fractures in thoracic pedicle approach was confirmed. Kirschner was placed and the accuracy of screw placement was confirmed with CT scanning. Template and the corresponding anatomical landmark fitted well, bone cement had showed good filling. The average printing time of upper thoracic spine model with soft tissue, the mean time of nail guide design, guide template production and cost were (719.00±3.03) min, (12.30±1.01) min, (55.50±10.30) min and RMB 3 150 yuan on average respectively. CONCLUSION: By means of individual design and 3D soft tissue printingtechnology, accurate placement of guided template of middle and upper thoracic percutaneous vertebroplasty could be realized.

[Meta-analysis of direct anterior approach and other approaches for hemiarthroplasty in elderly patients with femoral neck fracture].

OBJECTIVE: To systematically evaluate the clinical efficacy of high-quality direct anterior approach (DAA) and other approaches for the treatment of elderly patients with femoral neck fracture. METHODS: Literatures published in English or Chinese about the direct anterior approach and other approaches for hemiarthroplasty in femoral neck fracture were searched on Cochrane Library, PubMed, EMBASE, Web of science, Wanfang, CNKI databases from their establishment to May 2019. According to the inclusion and exclusion criteria, two researchers independently screened the literatures, and extracted the data. The quality of RCT were evaluated by Cochrane Risk of Bias Assessment Tool, and non-RCT were evaluated by the NOS scale. Meta-analysis was performed using the RevMan 5.3 software. RESULTS: A total of 9 articles were included with 901 cases, in which 429 cases used DAA, and 472 used other approaches. DAA had a significantly lower dislocation rate compared to subgroup of posterior and posterolateral approach [OR=0.19, 95%CI (0.06, 0.61), P=0.005]. No significant differences were found between DAA group and subgroup of direct lateral and anterolateral approach[OR=1.08, 95%CI(0.20, 5.76), P=0.93]. Also there were no relevant differences between the DAA group and control in infection rate[OR=1.07, 95%CI(0.47, 2.43), P=0.88], perioperative fracture rate[OR=0.95, 95%CI(0.36, 2.50), P=0.92], re operation rate[OR=0.76, 95%CI(0.30, 1.89), P=0.55], overall complication rate [OR=0.88, 95%CI (0.63, 1.22), P=0.44], mortality [OR=1.33, 95%CI (0.84, 2.11), P=0.23], operative time[MD=1.43, 95%CI(-5.85, 8.71), P=0.70]. CONCLUSION: The current evidenceindicates that the DAA was associated with a significantly lower dislocation rate compared to posterior capsular approaches for hemiarthroplasty. There was no significant difference in dislocation rate with the lateral and anterolateral approach.

[Comparative study of percutaneous bridging plate and retrograde suprapubic intramedullary screw fixation for anterior pelvic ring fracture].

OBJECTIVE: To compare the effect of percutaneous bridging plate and retrograde suprapubic intramedullary screw in the treatment of anterior ring fracture of pelvis. METHODS: From January 2013 to June 2017, 40 patients with unstable pelvic fractures involving anterior ring were analyzed retrospectively. According to the fixation method, they were divided into two groups, there were 20 patients in percutaneous bridging plate group (plate group) including 9 males and 11 females; according to tile classification, fractures were classified as type B1 in 1 case, type B2 in 14, type B3 in 2, type C1 in 2 and type C2 in 1. There were 20 cases in retrograde suprapubic intramedullary screw group (screw group) including 10 males and 10 females; according to tile classification, there were 1 case of type B1, 12 cases of type B2, 3 cases of type B3, 3 cases of type C1 and 1 case of type C2. The incision length, operation time, times of fluoroscopy, intraoperative bleeding volume, postoperative Matta score, postoperative complications and the last follow-up Majeed function score of the two groups were compared and analyzed. RESULTS: Both groups were followed up for 8 to 15 (12.25±2.24) months in the plate group and 6 to 18 (12.4±2.6) months in the screw group, there was no significant difference between the two groups. The incision length of screw group was (3.85±0.75) cm shorter than that of steel plate group (7.05±1.39) cm; the operation time of screw group was (27.70±5.36) min longer than that of steel plate group (15.10±2.07) min; the fluoroscopy times of screw group was (6.00±1.83) more than that of steel plate group (3.75±1.33) . The bleeding volume was (22.50±10.82) ml in of screw group, (25.00±9.93) ml in steel plate group, there was no significant difference between the two groups (P>0.05) . There was no significant difference in Matta evaluation and Majeed functional score in the last follow-up. One case of superficial skin infection occurred in screw group, one case of superficial skin infection and one case of transient paralysis of lateral femoral cutaneous nerve occurred in steel plate group. CONCLUSION: Percutaneous bridging plate and retrograde suprapubic intramedullary screw fixation of pelvic anterior ring fracture have the same effect. The operation time of the percutaneous plate group was shorter, the times of intraoperative fluoroscopy was less, and the learning curve was shorter, but the variation of the lateral femoral cutaneous nerve should be noted during the operation.

[Application of reverse dermal revascularization combined with vacuum sealing drainage in the large area of skin avulsion of the lower extremities].

OBJECTIVE: To summarize the clinical effect of emergency subcutaneous vascular network reverse skin replantation combined with vacuum sealing after drainage of large area skin avulsion injury. METHODS: Clinical data of 30 patients with extensive skin avulsion of the lower limb treated between July 2010 and March 2018 were collected. There were 20 males and 10 females, ranging in age from 16 to 67 years old, with an average of(48±13) years old. Cause of injury: 19 cases of car accident injury, 11 cases of crush injury. The surgery time was 3 to 10 h, with an average of (5±1) h. All cases were completely debrided in stage I. The subdermal vascular network was reversed and skin grafted with multiple incision drainage combined with negative pressure closed drainage technique for 7 to 10 days. The wounds were removed by VSD observation:if the necrotic area is large, debridement is required. After the granulation growth of the wound is satisfactory, the skin grafting is performed again after electrification; the small area of necrotic skin strengthens the dressing and heals. RESULTS: 30 patients were followed up for 7 to 48 months, with an average of (20±11) months.No infection in 1 case appeared, 30 patients, living area more than 85% of the wound after treatment survival in the stage I; The skin necrosis ranged from about 12% in 5 patients in the stage II. The second stage was healed after redebriding free skin grafts. The other patients were healed after the dressing, capillary meshwork layer of skin color, good elasticity, feeling, wearable pressure, each joint activities is good, no obvious skin adhesion cause physical activity is limited. CONCLUSIONS: Reverse skin grafting combined with VSD for the treatment of large skin avulsion of lower limb can greatly reduce wound infection rate, promote the application of skin and wound, conducive to drainage, improve the survival rate of reverse skin grafting and improve the function of lower limb joints.

T-plate fixation for unstable proximal clavicula fractures.

OBJECTIVE: The aim of this study was to evaluate the clinical results of T-plate fixation and anterior sternoclavicular ligament repair in proximal clavicle fractures. METHODS: Between August 2013 and August 2016, a total 12 patients (10 men and 2 women; mean age: 44.1 ± 9.1 years (range, 25-59 years)) with unstable proximal clavicle fractures (Throckmorton, type D) were treated with T-type plate fixation, bridging the sternoclavicular joint, and anterior sternoclavicular ligament repair. Average operative time, associated injuries, postoperative complications, postoperative fracture healing time and follow-up time were recorded. The outcomes were evaluated with radiographic assessment, visual analog scale (VAS) pain score and Rockwood SCJ scoring system. All the patients were evaluated on postoperative 3rd, 6th, and 12th months. RESULTS: The average surgery time was 78.0 ± 8.47 minutes while fracture healing time was 4.51 ± 0.95 months. According to Rockwood SCJ scoring system, 9 cases (75%) were in excellent, 2 cases (16.7%) in good and 1 case (8.3%) in fair condition at 12 months follow-up. The average Rockwood SCJ score was 7.7 ± 0.75 preoperatively, 12.7 ± 0.86 by 3 months, 13.0 ± 0.73 by 6 months and 13.3 ± 0.49 by 12 months. The VAS pain score was 7.9 ± 1.15 (preoperative score), 3.4 ± 1.52 (3 months follow-up), 3.0 ± 1.32 (6 months follow-up) and 2.1 ± 1.07 (12 months follow-up). The VAS and Rockwood SCJ scores were significantly improved postoperatively (p < 0.05). There was no intraoperative complication, while one patient had redislocation of the sternoclavicular joint after implant removal. CONCLUSION: T-type plate fixation with anterior sternoclavicular ligament repair might be a reliable and effective treatment method in unstable proximal clavicle fractures (type D) with few complications and satisfactory clinical results after 12 months follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic study.

[Surgical treatment of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach].

OBJECTIVE: To investigate the surgical treatment and outcome of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach. METHODS: From September 2012 to September 2016, 15 patients with capitellum and trochlea fractures were treated by Kaplan approach associated with anteromedial approach. Of the 15 cases, there were 6 males and 9 females, aged from 21 to 69 years old, with a mean of (42.0±10.5) years old. Eight patients had fractures on the left and 7 patients on the right. All the fractures were classified into type IIA(5 cases), type IIIA(4 cases) and type IIIB (6 cases) according to Dubberley classification. The results were evaluated by Mayo elbow function score for analysis. RESULTS: All the patients were followed up, the mean follow-up duration was(13.0±4.7) months(ranged 8 to 26 months). The mean Mayo elbow function score was 85.6±5.3(ranged 76 to 94). Postoperative follow-up had 4 cases excellent, 7 cases good, and 4 cases fair. Average arc of motion in elbow was(129.2±12.1)° in flexion and(6.6±1.9)° in extension. CONCLUSIONS: The surgical treatment of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach can better expose the fractures to achieve the satisfactory exposure and finish the surgical procedure, and the short-term outcome is satisfactory.

[Meta analysis of unilateral condylar replacement and high tibial osteotomy in the treatment of medial compartment osteoarthritis of the knee].

OBJECTIVE: Meta-analysis was used to compare the clinical efficacy of high tibial osteotomy(HTO) and unicondylar arthroplasty (UKA) in the treatment of medial compartment osteoarthritis (MIOA) and provide a better surgical choice for patients with MIOA. METHODS: The Cochrane Library (Issue 6, 2017), PubMed, Ovid, ELSIVE, CNKI and Wanfang databases were searched by a computer. Literatures on HTO and UKA for MIOA from January 1, 1970 to June 30, 2017, including complications, knee joint score, knee mobility, revision rate and excellent and good rate, were searched and screened out according to the inclusion criteria, and strict quality evaluation was carried out. RevMan 5.0 software provided by Cochrane collaboration network was used to conduct the meta-analysis of the included research results and to test the heterogeneity of the data. RESULTS: Total 13 articles met the inclusion criteria, and the total sample size was 1 043. Among them, 462 were HTO treatment group and 581 were UKA treatment group. By comparison between HTO treatment group and UKA treatment group, there were significant differences in the contralateral deterioration rate[WMD=3.21, 95%CI(1.13, 9.10)], pre-operative knee range of motion[WMD=6.55, 95%CI(1.44, 11.66)], Lysholm knee score[WMD=-3.15, 95%CI(-4.77, -1.53)], complications[WMD=2.78, 95%CI(1.52, 5.11], revision rate[WMD=1.81, 95%CI(1.17, 2.80)], the rate of excellent and good[WMD=0.49, 95%CI(0.30, 0.80)], and femorotibial angle changes[WMD=-2.37, 95%CI, (-3.63, -1.11)](P<0.05). There were no significant differences between the HTO treatment group and the UKA treatment group in patellofemoral deterioration rate[WMD=1.59, 95%CI(0.65, 3.84)] and the free walking speed[WMD=-0.02, 95%CI(-0.09, 0.04)](P>0.05). CONCLUSIONS: Based on the limited data, high tibial osteotomy is a better choice for the treatment of medial compartment osteoarthritis in the comparison of short and medium-term clinical outcomes, and long-term clinical outcomes may need further study.

Effects of erythropoietin for precaution of steroid-induced femoral head necrosis in rats.

BACKGROUND: Steroids such as glucocorticoid have been widely used for their excellent anti-inflammatory, anti-immune, and anti-shock properties. However, the long-term use in high doses has been found to cause necrosis of femoral head and other serious adverse reactions. Thus, it is of great importance to safely use these medications on patients without inducing bone necrosis. METHODS: In this preclinical study, we examined the effects of erythropoietin (EPO) to attenuate the induction of steroid-induced femoral bone necrosis using rats to build up the in-vivo models. Rats were randomly divided into three groups: negative control group (group A), disease group (group B), and EPO group (group C). 20 mg/kg methylprednisolone was administrated into group B and group C for 6 weeks with two intramuscular injections per week per rat. Group C was further given daily intraperitoneal injections of rHuEPO during this period. Group A received only injection of saline at the same schedule. 12 weeks after the initial drug administration, the rats' femoral tissues were harvested for HE staining, immunohistochemistry studies for PECAM-1(also CD31) expression and Western Blotting for VEGF expression. RESULTS: Histology studies showed that compared with the disease group, EPO group had significant improvement and bone morphology being much closer to the negative control group. Immunohistochemical studies revealed that EPO group had statistically much more expression of PECAM-1 than the other groups did. Western Blot demonstrated that the EPO group had significantly higher VEGF expression than the disease group. CONCLUSION: Results suggested that simultaneous injection of EPO could partially prevent steroid-induced ANFH.

[Biomechanical study of the stability of subaxial cervical anterior transpedicular screw fixation for three-column injury].

OBJECTIVE: To compare the stability of subaxial cervical anterior transpedicular screw(ATPS) fixation and three traditional fixations for three-column injury. METHODS: Six specimens of cervical spine were prepared. After measurememt of the range of motion(ROM) in intact state, the specimens were made into three-column injury models. The models were reconstructed with an anterior cervical cage, and stabilized by ATPS, anterior plate(AP), anterior plate + lateral mass screw(AP+LMS) and posterior transpedicular screw(PTPS). The ROM of the models in the four states were measured, and the results of data were compared after standardization. RESULTS: The normalized ROM of ATPS state in flexion-extension, lateral bending, axial rotation were(77.17±4.75)%, (82.00±2.61)%, (83.17±2.23)%, which were significant small than those in intact state(P<0.05). The normalized ROM of AP state in flexion-extension, lateral bending, axial rotation were(119.67±7.42)%, (116.33±7.53)%, (112.67±5.99)% , which were significant larger than those in intact state(P<0.05). The normalized ROM of AP in all directions were significant larger than those of ATPS(P<0.05). There was no significant difference between normalized ROM of PTPS state and those of ATPS state in flexion-extension and lateral bending(P>0.05). The normalized ROM of PTPS state in axial rotation was(6.83±2.48)% and was significant larger than that of ATPS state(P=0.009). The normalized ROM of AP+LMS state in flexion-extension was(68.50±2.43)%, which was significant smaller than that of ATPS state(P=0.003). There was no significant difference between the normalized ROM of AP+LMS state and those of ATPS state in lateral bending and axial rotation(P>0.05). CONCLUSIONS: Subaxial cervical three-column injury model reconstruction by ATPS can provide the adequate primary stability, of which biomechanics property is superior compared to AP and PTPS, and is similar to that of AP+LMS. It can be applied to the patients with no need to decompression and reduction through posterior approach.

Down-regulated miR-448 relieves spinal cord ischemia/reperfusion injury by up-regulating SIRT1.

MicroRNAs play a crucial role in the progression of spinal cord ischemia/reperfusion injury (SCII). The role of miR-448 and SIRT1 in SCII was investigated in this study, to provide further insights into prevention and improvement of this disorder. In this study, expressions of miR-448 and SIRT1 protein were determined by qRT-PCR and western blot, respectively. Flow cytometry was used to analyze cell apoptosis. The endogenous expression of genes was modulated by recombinant plasmids and cell transfection. Dual-luciferase reporter assay was performed to determine the interaction between miR-448 and SIRT1. The Basso, Beattie, and Bresnahan score was used to measure the hind-limb function of rat. The spinal cord ischemia reperfusion injury model of adult rats was developed by abdominal aorta clamping, and the nerve function evaluation was completed by motor deficit index score. In SCII tissues and cells treated with hypoxia, miR-448 was up-regulated while SIRT1 was down-regulated. Hypoxia treatment reduced the expression of SIRT1 through up-regulating miR-448 in nerve cells. Up-regulation of miR-448 induced by hypoxia promoted apoptosis of nerve cells through down-regulating SIRT1. Down-regulated miR-448 improved neurological function and hind-limb motor function of rats with SCII by up-regulating SIRT1. Down-regulated miR-448 inhibited apoptosis of nerve cells and improved neurological function by up-regulating SIRT1, which contributes to relieving SCII.

Stability of two anterior fixations for three-column injury in the lower cervical spine: biomechanical evaluation of anterior pedicle screw-plate fixation.

Objectives This study aimed to evaluate the stability of anterior pedicle screw-plate (APSP) fixation and anterior vertebral body screw-plate (AVBSP) fixation for three-column injury in the lower cervical spine. Methods Six fresh-frozen human cadaveric specimens of the lower cervical spine were prepared. After measurement of the range of motion (ROM) in the intact state, the specimens were prepared as three-column injury models. The models were stabilized by AVBSP or APSP fixation. The ROM of the models in the two states was measured. The ROM in the two states was compared. Results The ROM of the intact state in all directions was significantly smaller than that of the AVBSP state and significantly larger than that of the APSP state. The ROM of the AVBSP state in all directions was significantly larger than that of the APSP state. Conclusions This study shows that APSP fixation can provide sufficient stability for three-column injury in the lower cervical spine. The primary stability of our models using APSP fixation is superior to that of AVBSP fixation. These results suggest that APSP can be used for three-column injury in the lower cervical spine.