Down-Regulation of Ribosomal Protein RPS21 Inhibits Invasive Behavior of Osteosarcoma Cells Through the Inactivation of MAPK Pathway.

OBJECTIVE: The goal of our present study was to explore the expression level, biological function, and underlying molecular mechanism of ribosomal protein s21 (RPS21) in human osteosarcoma (OS). METHODS: Firstly, we evaluated the expression of RPS21 in OS tissue samples based on the Gene Expression Omnibus (GEO) datasets and also measured the RPS21 expression of OS cell lines (MG63, and U2OS) by quantitative real-time polymerase chain reaction (qRT-PCR). siRNA interference method was used to reduce the expression of RSP21 in the OS cells. Cell Counting Kit-8 (CCK-8), colony formation, wound-healing, and transwell assays were conducted to measure the proliferation, migration, and invasion of OS cells. The mitogen-activated protein kinase (MAPK) pathway-related proteins levels were examined by Western blot. RESULTS: Our analyses showed that the expression of RPS21 was significantly increased in OS, compared with normal samples. Upregulation of RPS21 was associated with worse outcomes of OS patients. Knockdown of RPS21 suppressed OS cell proliferation, colony-forming ability, migration, and invasion capacities. Moreover, down-regulation of RPS21 inactivated the MAPK signaling pathway. CONCLUSION: RPS21 plays an oncogenic candidate in OS development via regulating the activity of MAPK pathway; therefore, it may serve as a novel therapeutic target for OS treatment.

[Progress on prevention for anterior knee pain after primary total knee arthroplasty].

Total knee arthroplasty (TKA) identified as an effective treatment for ultimate knee joint disease can effectively relieve pain, correct deformity, improve knee function and enhance the quality of life of patients. Patient satisfaction has been increasingly considered as an important factor in evaluating the success of primary TKA. Anterior knee pain that usually appears in the region of the anterior knee is a recognized complaint for primary TKA and has a strong impact on the improvement of knee function and patient satisfaction of primary TKA. Accordingly, the relief of anterior knee pain has become one of the primary goals of primary TKA. At present, soft tissue lesions around the patellar caused by patellar maltracking and the elevation of internal pressure in subchondral bone because of the high contact stress of patellofemoral joint are both considered as the mechanism of anterior knee pain. For the past few years,on increasing number of studies have focused on the prevention of anterior knee pain following primary TKA. However, none of the past treatment such as patellar resurfacing, patellar denervation without patellar resurfacing or a mobile-bearing prosthesis has a good and affirmative effect on it. The prevention and treatment of anterior knee pain following primary TKA still is a difficult solved problem. To address this problem, we need further researches about the cause of anterior knee pain, knee joint prosthesis and biomechanics of patellofemoral joint, as well as lots of randomized controlled trials.

[Effects of body mass index on postoperative outcome in patients with osteoarthritis after total knee arthroplasty].

OBJECTIVE: To study effects of body mass index (BMI) on postoperative outcome in patients with osteoarthritis after total knee arthroplasty (TKA). METHODS: The data of 148 patients with osteoarthritis who underwent TKA from June 2006 to May 2009 in our hospital and had complete follow-up data were analyzed restrospectively, including 29 males and 119 females, ranging in age from 39 to 89 years old, with an average age of 71.2 years old. According to BMI classification standard, all the patients were divided into 4 groups: non-obese group (BMI ≤ 25.0 kg/m2), had 38 patients (45 knees), including 9 males and 29 females, with a mean age of (70.0 ± 8.2) years old; overweight group (BMI 25.1 to 27.0 kg/m2), had 40 patients (48 knees), including 10 males and 30 females, with a mean age of (72.6 ± 7.4) years old; obesity group (BMI 27.1 to 30.0 kg/ m2), had 30 patients (43 knees), including 7 males and 30 females, with a mean age of (70.4 ± 6.0) years old; morbidly obesity group (BMI > 30.0 kg/m2), 33 patients (39 knees), including 3 males and 30 females, with a mean age of (71.7 ± 6.4) years old. The index such as Knee Society Score (KSS), anterior knee pain and patella cartilage damage during surgery were recorded before surgery and at the time of follow-up. RESULTS: Postoperative KSS increased significantly compared to preoperative KSS, and the good rate reached to 97.1%. In the knee score, preoperative KSS and postoperative KSS had no significant differences among the four groups (preoperative P = -0.789; postoperative P = 0.133). However, compared with other groups, obesity group got the lowest preoperative function score (preoperative P = 0.036; postoperative P = 0.225). While the incidence of anterior knee pain was 9.7% (17/175), including 14 grade I and 3 grade II. There were no significant differences in incidence of anterior knee pain among four groups (χ2 = 0.764, P = 0.862). The average BMI of the patients with anterior knee pain was (27.4 ± 3.6) kg/m2, while the others' BMI was (27.5 ± 4.4) kg/m2. There was no statistically difference between two groups (t = -0.061, P = 0.951). There were no significant differences in patella cartilage damage among groups (χ2 = 7.070, P = 0.314). CONCLUSION: The KSS increases in all the different groups. Those patients get the benefit from TKA, and the obese patients can receive a similar postoperative outcome as the non-obese ones.

[Augmentative locking compression plate (LCP) combined with bone graft for the treatment of aseptic femoral shaft nonunion after intramedullary nailing].

OBJECTIVE: To investigate the effect of augmentative locking compression plate combined with bone graft in treating aseptic femoral shaft nonunion after intramedullary nailing. METHODS: Twenty-one cases with aseptic femoral shaft nonunion after intramedullary nailing from January 2007 to January 2013 were treated,including 18 males and 3 females with a mean age of 37.7 years (ranged from 23 to 64 years). The mean period of nonunion after surgery was 23.9 months (ranged from 9 to 62 months). According to Weber-Cech classification,10 of those 21 cases were hypertrophic nonunion,7 were atrophic, and 4 had oligotrophic fracture nonunion. All patients retained the original intramedullary nail, and applied with augmentation plating of 6 to 8 holes locking compression plate, unicortical fixation with 2 to 3 locking screws in the proximal or distal end, with simultaneous autologous iliac bone grafting. After treatment,all patients were allowed to partial weight-bearing until full weight-bearing according to the radiological results. All patients were followed up and were evaluated with clinical and imaging results. RESULTS: All patients were followed up from 8 to 24 months, averaged (13.5±3.5) months,which showed clinical union at 4 to 8 months, averaged (6.0±1.0) months and radiological solid union at 7 to 12 months, averaged (9.1±1.5) months. No such complications as infection,hardware loosening or breaking were found. CONCLUSION: Augmentative locking compression plate(LCP) combined with bone graft for aseptic femoral shaft nonunion after intramedullary nail has a satisfied clinical efficacy. It's an useful and simple method.

[Percutaneous kyphoplasty for the treatment of senior patient with acute and chronic osteoporotic vertebral compression fractures].

OBJECTIVE: To discuss the clinical effects of percutaneous kyphoplasty (PKP) for acute and chronic osteoporotic vertebral compression fractures (OVCF). METHODS: From June 2006 to October 2011,42 senior patients with OVCF were treated with PKP. There were 5 males and 37 females,ranging in age from 60 to 86 years old with an average of (73.3+/-7.5) years old. The patients were divided into two groups (acute group and chronic group) according to the course,MRI and whether or not undergoing systematically conservative. VAS and ADL scoring systems were used to evaluate the pain and daily activities. X-ray was used to evaluate the vertebral height restoration rate and the kyphosis correction rate. RESULTS: All patients were followed up from 10 to 64 months with an average of 17 months. At 1 week and 6 months after operation in two groups, VAS and ADL scores decreased significantly (P<0.05) ;VAS and ADL scores at 6 months after operation were higher than at 1 week after operation (P>0.05). But the improvement rates of the pain and daily activities of acute group were better than that of chronic group (P<0.05). At 1 week after operation,the restoration rate of anterior and middle vertebral height,the kyphotic correction rate in acute group were better than that of chronic group (P<0.05). CONCLUCSION: Using PKP to treat both acute and chronic osteoporotic vertebral compression fractures can get good effects,but acute patients can obtain better effects than chronic patients,it has obviously advantages of relieving pain,correcting kyphotic angle,recovering vertebral height.