Comparison between infrapatellar and suprapatellar approaches for intramedullary nailing for the fractures of the tibial shaft.

INTRODUCTION: This study aimed to compare the outcomes at the clinical and functional levels of suprapatellar (SP) and infrapatellar (IP) approaches for intramedullary nailing in treating tibial shaft fracture. METHODS: Patients who underwent tibial shaft fracture intramedullary nailing by the SP approach or IP approach in a trauma center were retrospectively reviewed. The demographics, intraoperative fluoroscopy time, operation time, blood loss, irrigation volume, postoperative X-ray alignment, and complications of patients were compared between the two groups under different approaches. Lysholm knee score, visual analog score (VAS), and incidence of anterior knee pain (AKP) were assessed 1 year after surgery. RESULTS: The study finally included well-documented 81 patients (38 SP versus 43 IP). The SP group exhibited significantly shorter intraoperative fluoroscopy time than that of the IP group (81.7 ± 14.5 s vs. 122.0 ± 24.3 s, P < 0.001). Both aspects recorded a precise reduction of the fracture: angulation (2.1 ± 1.2° vs 3.1 ± 1.5°, P < 0.05) and translation (0.6 ± 0.8 mm vs 1.4 ± 1.5 mm, P < 0.05) in the coronal plane in the SP group. However, the sagittal plane recorded no such change (P > 0.05). The Lysholm knee score was higher in the SP group than that of the IP group (87 ± 8 vs. 80 ± 15, P < 0.05). The SP group displayed an evidently lower average VAS score than that of the IP approach group (0.3 ± 0.8 vs 1.3 ± 1.4, P < 0.001). Six cases (16%) in the SP group and 16 cases (37%) in the IP group experienced AKP 1-year post-operation (P < 0.05). As far as complications are concerned, neither group showed any significant difference (P > 0.05). CONCLUSION: Compared with the IP approach, the application of intramedullary nailing through the SP approach in treating tibial shaft fractures can effectively shorten the intraoperative fluoroscopy time, correct coronal plane angulation and translation deformity, reduce the incidence of AKP and improve postoperative function.

Capsular Healing in Interportal and Periportal Capsulotomy Methods of Hip Arthroscopy.

OBJECTIVE: To evaluate the midterm outcomes and the capsular healing in patients who had interportal capsulotomy versus periportal capsulotomy of hip arthroscopy. METHODS: Retrospectively reviewed 33 patients with labral tear received hip arthroscopy, with an average age of 41 (27-67) years, including 13 cases of Cam deformity and three cases of Pincer deformity. All patients had positive sign of flexion adduction internal rotation or flexion abduction external rotation. With MRI and radiographic (CT, X plain) imageological examination. MRI showed that all patients had labral tear. Radiographic finding (CT, X plain) showed the pathological changes of acetabular and femoral neck osteophyte. One group with 23 patients were treated with periportal capsulotomy. Another group with 10 patients were treated with interportal capsulotomy. All patients did not close the capsule. Clinical outcomes were measured with the Hip Outcome Score Activities of Daily Living (HOS-ADL) and the modified Harris Hip Score (mHHS), patient satisfaction measured with visual analogue scale (VAS). The healing of the capsule was evaluated by MRI. MRI showed continuous capsular indicated healing, discontinuous capsular indicated unhealing. Postoperatively 6 months, mHHS and HOS-ADL were obtained. Randomized controlled trials were used in this study for analysis. RESULTS: All patients were followed up with average time of 9.3 months(3-29 months). The postoperative symptoms were obviously relieved, the VAS decreased from (4.9 ± 0.6) to (1.2 ± 0.2) after 3 months postoperative. Follow up 6 months post-operation, patients in the interportal group, the mHHS and HOS-ADL scores improvement were respectively 69.4 ± 9.3 & 70 ± 8.8 pre-operation, and 92.5 ± 5.0 & 86.6 ± 5.4 post-operation (P < 0.05); Patients in the periportal group, the mHHS and HOS-ADL scores improvement were respectively 69.9 ± 15.8, 68.1 ± 15.0 pre-operation, and 90.1 ± 9.3 & 86.7 ± 7.9 post-operation (P < 0.05).The differences were statistically significant. Six months after operation, MRI showed that 23 patients with periportal capsulotomy, the capsule have healed, without other complications. Three of the ten patients with interportal capsulotomy were healed and seven were not. CONCLUSION: Interportal and periportal capsulotomy had good outcomes. The technique of periportal capsulotomy had little damage to the joint capsule. Although the capsule did not close, the capsule healed well in postoperative follow-up. The nonunion rate of the joint capsule was high in the interportal capsulotomy without close the capsule.

[Pressure side and tension side comminution of femoral neck cortex are independent risk factors for aseptic necrosis after femoral neck fracture surgery].

OBJECTIVE: To investigate the related factors of aseptic necrosis of femoral head after closed reduction and internal fixation of femoral neck fracture. METHODS: From January 2009 to January 2016, 236 patients with femoral neck fracture were treated with closed reduction and internal fixation with 3 hollow lag screws, including 111 males and 125 females, aged from 19 to 89 (50.17±12.88) years. According to the follow-up results, the correlation of aseptic necrosis of femoral head was analyzed. Univariate analysis of age, gender, injured side, body weight, injury mechanism, preoperative waiting time, Garden classification and whether there was comminution of femoral neck cortex was conducted to obtain the independent variables with significant difference. Then binary logistic regression analysis was conducted to explore the independent risk factors of avascular necrosis of femoral head. RESULTS: The average follow-up period of 236 cases was 4.58 years. There were significant differences in the range of injury (24.69% vs. 5.16%, χ2=19.405, P=0.000), operation waiting time>48 hours (20.00% vs. 6.38%, χ2=10.065, P=0.002), Garden type Ⅲ/Ⅳ (18.52% vs. 2.97%, χ2=13.357, P=0.000), femoral neck cortex comminution (66.67% vs. 4.88%, χ2=39.968, P=0.000). Multivariate logistic regression analysis showed that:injury mechanism [high energy injury, Exp (B)=4.397, 95%CI=(1.672-11.562), P=0.003], preoperative waiting time >48 h [Exp (B)= 3.060, 95%CI=(1.176-7.966), P=0.022], comminution of femoral neck cortex [comminution of femoral neck pressure side cortex, Exp (B)=3.944, 95%CI=(1.245-12.494), P=0.020;comminution of femoral neck pressure side and tension side cortex, Exp(B)= 23.761, 95%CI=(3.805-148.374), P=0.001) were independent risk factors for avascular necrosis after internal fixation of femoral neck fracture. Garden type Ⅲ/Ⅳ was not an independent risk factor in this study [Exp (B) = 1.985, 95%CI=(0.436-9.032), P=0.375]. CONCLUSION: High energy injury, preoperative waiting time (>48 h) and comminution of femoral neck cortex were independent risk factors for aseptic necrosis of femoral head. In addition, cortical comminution on the pressure side and tension side of the femoral neck is a strong prognostic risk factor for aseptic necrosis of the femoral head, because it indicates a more serious and complex injury mechanism.

Application of the Chinese Aircraft-shaped Sleeve system in the treatment of tibial shaft fractures using a suprapatellar approach for tibial intramedullary nailing: a randomised controlled trial.

BACKGROUND: The use of the suprapatellar approach for intramedullary nailing has recently become popular for the treatment of tibial fractures. This study aimed to investigate the effectiveness of using the Chinese Aircraft-shaped Sleeve (CASS) system on the clinical outcomes of tibial intermedullary nailing using a suprapatellar approach for the treatment of tibial fractures in a cohort of adult Chinese patients. METHODS: Magnetic resonance images (MRI) of the knee joints of 212 healthy adults with normal lower limb function from May 2011 to May 2015 were obtained from a level I Chinese regional trauma centre. Sixty inpatients at the same trauma centre who underwent treatment for tibial shaft fractures from June 2015 to June 2018 were enrolled. Tibial intramedullary nailing fixation of tibial shaft fractures via the suprapatellar approach was performed with either a CASS system or a conventional sleeve. The measurements of patellofemoral joint anatomy, the surgical time, the assessments of the patellofemoral joint cartilage conditions, and information of residual debris based on arthroscopic analysis were subsequently collected. RESULTS: The mean patellar angle (PA), sulcus angle (SA), sulcus width (SW) and sulcus depth (SD) were 135.40 ± 6.20°, 142.37 ± 5.33°, 33.37 ± 2.73 mm, and 4.29 ± 0.63 mm, respectively. The surgical time until entry reaming commencement and the irrigation time were significantly lower in the CASS group (P < 0.001). The difference in cartilage damage rate between groups was statistically significant (P = 0.031); the difference in residual debris conditions was not statistically significant (P = 0.1967). CONCLUSION: The use of the CASS system could improve clinical outcomes of intramedullary nailing via suprapatellar approach for patients with a small patellofemoral joint space.

[Clinical study of the application of enhanced recovery after surgery in cervical spondylotic myelopathy].

OBJECTIVE: To evaluate the role of enhanced recovery after surgery in treating cervical spondylotic myelopathy. METHODS: The clinical data of 55 patients with cervical spondylotic myelopathy underwent surgical treatment from January 2012 to December 2015 were retrospectively analyzed. There were 30 males and 25 females, age from 36 to 71 years old with an average of (45.2±3.2) years, course of disease was for 1 to 12 months with an average of (4.5±1.8) months. The concept of enhanced recovery after surgery and perioperative management were applied to surgical treatment in 35 patients (study group), and the same period, 20 patients without strategy of enhanced recovery after surgery (control group). Thirty-eight patients were treated by anterior cervical discectomy decompression and fixation(ACDF), 17 patients were treated by posterior single-open door laminoplasty decompression. The activity time out of bed, hospitalization days after surgery were compared between two groups. Japanese Orthopaedic Association (JOA) score and visual analogue score(VAS) before operation, after operation at 1, 7, 30 days and 6, 12 months was respectively used to evaluate the neurological function and pain. RESULTS: All the patients were followed up for 12 to 18 months with an average of (14.3±1.5) months. There was no significant difference in age, gender, surgical methods, preoperative VAS, JOA score between two groups (P>0.05). The activity time out of bed was 3 to 8 h with an average of (5.54±1.54) h, postoperative hospitalization time was 3 to12 d with an average of (5.62±1.59) d in study group, while in control group, the activity time out of bed was 24 to 48 h with an average of (18.80±4.78) h, and postoperative hospitalization time was 7 to 17 d with an average of (9.85±1.94) d; there was significant difference between two groups (P<0.01). There was significant difference in VAS and JOA scores between two groups at 1, 7, 30 d after operation (P<0.01), and there was no significant difference at 6, 12 months after operation(P>0.05). There were no neurologic function deterioration, hematoma, wound infection, internal fixation loosening and other complications in study group during hospitalization and following-up;there were 2 cases of superficial wound infection in the control group, who healed by dressing change for 2 weeks;there was no significant difference between two groups(P>0.05). CONCLUSIONS: The strategy of enhanced recovery after surgery in treating cervical spondylotic myelopathy can promote the early recovery, shorten the length of stay and improve the patient's degree of satisfaction.

Association between expression of nuclear receptor co-activator 5 protein and prognosis in postoperative patients with osteosarcoma.

The aim of the present study was to investigate the association between the expression of nuclear receptor co-activator 5 protein (NCOA5) and the prognosis of postoperative patients with osteosarcoma. Human osteosarcoma samples were collected from 145 patients and normal bone tissues were collected from 100 individuals as controls. Immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) were employed to measure the levels of NCOA5 protein in cases of human osteosarcoma. The results from the RT-PCR analysis demonstrated that the positive rate of NCOA5 mRNA expression in human osteosarcoma was 17.24% (25/145). The positive rate in normal bone tissues was 84.00% (84/100), which was significantly higher compared with that of human osteosarcoma tissues (χ2=33.166; P<0.001). IHC staining indicated that the positive rate of NCOA5 protein in the osteosarcoma samples was 26.21% (38/145). The positive rate in normal bone tissues was 82.00% (82/100), which was significantly increased compared with that of human osteosarcoma tissues (χ2=28.166; P<0.001). NCOA5 mRNA and protein expression levels were consistent in human osteosarcoma tissues, and were lower than in control tissues. The expression of NCOA5 was low in human osteosarcoma tissues, while it was high in normal bone tissues. These low NCOA5 expression levels were associated with postoperative survival of human osteosarcoma.

Ellipticine inhibits the proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes via the STAT3 pathway.

OBJECTIVE: Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole) is an alkaloid isolated from Apocyanaceae plants. This study was designed to investigate the effects of ellipticine on the proliferation and apoptosis of fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis (RA). METHODS: RA-FLSs were exposed to different concentrations of ellipticine (i.e., 0.5, 1, 2, 4 and 8 µM) for 24-72h and measured for viability, proliferation and apoptosis. The involvement of signal transducer and activators of transcription 3 (STAT3) signaling in the action of ellipticine was determined by Western blot analysis, luciferase reporter assay and rescue experiments. RESULTS: Ellipticine treatment significantly inhibited the viability and proliferation of RA-FLSs in a concentration-dependent manner. In contrast, ellipticine exposure did not alter the viability of normal human FLSs. Moreover, ellipticine triggered significant apoptosis and increased caspase-3 activity in RA-FLSs. Mechanistically, ellipticine reduced the phosphorylation of STAT3 and downregulated the expression of Mcl-1, cyclin D1 and Bcl-2. Luciferase reporter assay demonstrated that ellipticine treatment led to a significant inhibition of STAT3-mediated transcriptional activity in RA-FLSs. Overexpression of constitutively active STAT3 reversed the suppressive effects of ellipticine on RA-FLSs, which was accompanied by restoration of Mcl-1, cyclin D1 and Bcl-2. DISCUSSION AND CONCLUSIONS: Ellipticine shows anti-proliferative and pro-apoptotic effects on RA-FLSs through inhibition of the STAT3 pathway and may have therapeutic potential in RA.

X-ray therapy promotes structural regeneration after spinal cord injury in a rat model.

OBJECTIVE: This study aims to investigate the therapeutic effects and mechanisms of x-ray treatment on rats following spinal cord injury (SCI). METHODS: Forty-six female Sprague-Dawley rats were subjected to spinal cord injury using the modified Allen weight-drop method. The animals were randomly divided into six groups. Two of the animal groups were irradiated with 10 Gy at the lesion site; another two groups were irradiated with 20 Gy; and the last two groups without irradiation were regarded as the sham group. One of the each of two animal groups was euthanized at different time points at 4 and 12 weeks, respectively, after irradiation. Spinal cord calluses were assessed using kinology and electrophysiology and histology methods. RESULTS: In all of the groups, the neurofilament (NF) counts at 14 weeks were found to be higher than that at 6 weeks after SCI. Both 10-Gy irradiated and 20-Gy irradiated groups were higher than those of the sham group at each time point (P < 0.05). The myelin basic protein (MBP) count decreased at 14 weeks after SCI in the irradiated groups (P < 0.05) but increased at 14 weeks in the sham group (P < 0.05). Furthermore, the MBP count of the irradiated groups was lower than that of the sham group at 14 weeks (P < 0.05). The glial fibrillary acidic protein (GFAP) and Nogo-A counts at 14 weeks were higher than those at 6 weeks in all the groups (P < 0.05), and there was no statistical significance with kinology and electrophysiology tests in all groups. CONCLUSIONS: A self-repair mechanism exists after spinal cord injury, which lasts at least 14 weeks. X-ray therapy promotes the regeneration of the spinal cord system after injury.

Effects of transcutaneous electrical nerve stimulation on rats with the third lumbar vertebrae transverse process syndrome.

OBJECTIVE: To investigate the analgesic and anti-inflammatory effects of transcutaneous electrical nerve stimulation (TENS) at local or distant acupuncture points in a rat model of the third lumbar vertebrae transverse process syndrome. METHODS: Forty Sprague-Dawley rats were randomly divided into control, model, model plus local acupuncture point stimulation at BL23 (model+LAS) and model plus distant acupuncture point stimulation at ST36 (model+DAS) groups. All rats except controls underwent surgical third lumbar vertebrae transverse process syndrome modelling on day 2. Thereafter, rats in the model+LAS and model+DAS groups were treated daily with TENS for a total of six treatments (2/100 Hz, 30 min/day) from day 16 to day 29. Thermal pain thresholds were measured once a week during treatment and were continued until day 57, when local muscle tissue was sampled for RT-PCR and histopathological examination after haematoxylin and eosin staining. mRNA expression of interleukin-1 ß (IL-1ß), tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) was determined. RESULTS: Thermal pain thresholds of all model rats decreased relative to the control group. Both LAS and DAS significantly increased the thermal pain threshold at all but one point during the treatment period. Histopathological assessment revealed that the local muscle tissues around the third lumbar vertebrae transverse process recovered to some degree in both the model+LAS and model+DAS groups; however, LAS appeared to have a greater effect. mRNA expression of IL-1ß, TNF-α and iNOS in the local muscle tissues was increased after modelling and attenuated in both model+LAS and model+DAS groups. The beneficial effect was greater after LAS than after DAS. CONCLUSIONS: TENS at both local (BL23) and distant (ST36) acupuncture points had a pain-relieving effect in rats with the third lumbar vertebrae transverse process syndrome, and LAS appeared to have greater anti-inflammatory and analgesic effects than DAS. TRIAL REGISTRATION NUMBER: 09073.

Cigarette smoking and risk of hip fracture in women: a meta-analysis of prospective cohort studies.

BACKGROUND AND OBJECTIVES: Whether cigarette smoking can increase the risk of hip fracture in women is unclear. This meta-analysis, which pooled results from 10 prospective cohort studies, was performed to derive a more precise estimation between cigarette smoking and the risk of hip fracture in women. MATERIALS AND METHODS: Pubmed, Cochrane Central Register of Controlled Trials and ISI Web of Science were systematically searched to identify relevant studies. A meta-analysis was performed to examine the association among 10 studies. The pooled risk estimates were calculated by using both random- and fixed-effects model. Heterogeneity among articles and their publications bias were also tested. All of the statistical analyses were performed using the software programs STATA (version 12.0). RESULTS: Relative risk was significantly increased in current female smokers (pooled RR, 1.30; 95%CI, 1.16-1.45). The association was significant among the high-dose smokers (more than 15 cigarettes per day) while not among the low-does smokers (less than 15 cigarettes per day). Omission of any single study had little effect on the pooled risk estimate. Former smokers had a similar RR of hip fracture (RR, 1.02; 95%CI, 0.93-1.11) to published papers. Smoking cessation for ≥10 years leads to a significant decline in risk. CONCLUSIONS: Smoking is associated with an increased hip fracture risk in women. Cessation of smoking for ≥10 years had a decreased impact on risk of hip fracture. Given the inconsistency among the studies in the choice of adjustments, the associations between cigarette smoking and risk of hip fracture in women await further investigation.

Effects of hook plate on shoulder function after treatment of acromioclavicular joint dislocation.

INTRODUCTION: Internal fixation with hook plate has been used to treat acromioclavicular joint dislocation. This study aims to evaluate the effect of its use on shoulder function, to further analyze the contributing factors, and provide a basis for selection and design of improved internal fixation treatment of the acromioclavicular joint dislocation in the future. METHODS: A retrospective analysis was performed on patients treated with a hook plate for acromioclavicular joint dislocation in our hospital from January 2010 to February 2013. There were 33 cases in total, including 25 males and 8 females, with mean age of 48.27 ± 8.7 years. There were 29 cases of Rockwood type III acromioclavicular dislocation, 4 cases of type V. The Constant-Murley shoulder function scoring system was used to evaluate the shoulder function recovery status after surgery. Anteroposterior shoulder X-ray was used to assess the position of the hook plate, status of acromioclavicular joint reduction and the occurrence of postoperative complications. RESULTS: According to the Constant-Murley shoulder function scoring system, the average scores were 78 ± 6 points 8 to 12 months after the surgery and before the removal of the hook plate, the average scores were 89 ± 5 minutes two months after the removal of hook plate. Postoperative X-ray imaging showed osteolysis in 10 cases (30.3%), osteoarthritis in six cases (18.1%), osteolysis associated with osteoarthritis in four cases(12.1%), and steel hook broken in one case (3%). CONCLUSION: The use of hook plate on open reduction and internal fixation of the acromioclavicular joint dislocation had little adverse effect on shoulder function and is an effective method for the treatment of acromioclavicular joint dislocation. Osteoarthritis and osteolysis are the two common complications after hook plate use, which are associated with the impairment of shoulder function. Shoulder function will be improved after removal of the hook plate.

Assessment of tibial rotation and meniscal movement using kinematic magnetic resonance imaging.

OBJECTIVE: This work aimed to assess tibial rotations, meniscal movements, and morphological changes during knee flexion and extension using kinematic magnetic resonance imaging (MRI). METHODS: Thirty volunteers with healthy knees were examined using kinematic MRI. The knees were imaged in the transverse plane with flexion and extension angles from 0° to 40° and 40° to 0°, respectively. The tibial interior and exterior rotation angles were measured, and the meniscal movement range, height change, and side movements were detected. RESULTS: The tibia rotated internally (11.55° ± 3.20°) during knee flexion and rotated externally (11.40° ± 3.0°) during knee extension. No significant differences were observed between the internal and external tibial rotation angles (P > 0.05), between males and females (P > 0.05), or between the left and right knee joints (P > 0.05). The tibial rotation angle with a flexion angle of 0° to 24° differed significantly from that with a flexion angle of 24° to 40° (P < 0.01). With knee flexion, the medial and lateral menisci moved backward and the height of the meniscus increased. The movement range was greater in the anterior horn than in the posterior horn and greater in the lateral meniscus than in the medial meniscus (P < 0.01). During backward movements of the menisci, the distance between the anterior and posterior horns decreased, with the decrease more apparent in the lateral meniscus (P < 0.01). The side movements of the medial and lateral menisci were not obvious, and a smaller movement range was found than that of the forward and backward movements. CONCLUSION: Knee flexion and extension facilitated internal and external tibial rotations, which may be related to the ligament and joint capsule structure and femoral condyle geometry.

Calcitonin treatment is associated with less severe osteoarthritis and reduced toll-like receptor levels in a rat model.

BACKGROUND: Studies indicate that inflammation promotes progression of osteoarthritis. Cartilage damage is aggravated by the binding of toll-like receptors and endogenous ligands that release large amounts of cytokines and inflammation mediators. Calcitonin can inhibit degeneration of articular cartilage, by inhibiting activation of toll-like receptors and generation of endogenous ligands. To study the effect of calcitonin in the pathogenesis of osteoarthritis and the underlying molecular mechanism, we monitored levels of toll-like receptors during osteoarthritis progression, and after calcitonin injection. METHODS: Male Sprague-Dawley rats were randomly assigned to either a surgery-only or a calcitonin-treatment group (n = 35, each). To induce osteoarthritis, the anterior cruciate ligament and the medial meniscus were cut in the right knees of both groups. Rats in the calcitonin-treatment group received a subcutaneous injection of 15 IU/kg calcitonin once every other day, starting one day post-surgery, until euthanised. Signs of osteoarthritic changes were noted. The amount of collagen II was measured by antibody staining. The amounts of MMP1 and MMP3 in cartilage were measured by use of ELISA. RNA from operated and matched control knee cartilage was extracted to determine expression levels of Col2a1, ACAN, Tlr2, Tlr3, and Tlr4. RESULTS: Signs of osteoarthritis were less severe in rats treated with calcitonin. In the surgery-only group, Tlr2 levels increased early after surgery and then decreased substantially by the latter stages. Tlr3 levels gradually increased and correlated with the severity of osteoarthritis. Tlr4 levels were high but fluctuated over the experimental period. Calcitonin treatment was associated with lower Tlr3 and Tlr4 levels than in the surgery-only group whereas Tlr2 expression was initially lower but increased 28 days after administration of calcitonin. CONCLUSION: Calcitonin treatment may lessen the severity of osteoarthritis in the rat model, perhaps by inhibition of Tlr expression in cartilage.

Low-dose X-ray irradiation promotes osteoblast proliferation, differentiation and fracture healing.

Great controversy exists regarding the biologic responses of osteoblasts to X-ray irradiation, and the mechanisms are poorly understood. In this study, the biological effects of low-dose radiation on stimulating osteoblast proliferation, differentiation and fracture healing were identified using in vitro cell culture and in vivo animal studies. First, low-dose (0.5 Gy) X-ray irradiation induced the cell viability and proliferation of MC3T3-E1 cells. However, high-dose (5 Gy) X-ray irradiation inhibited the viability and proliferation of osteoblasts. In addition, dynamic variations in osteoblast differentiation markers, including type I collagen, alkaline phosphatase, Runx2, Osterix and osteocalcin, were observed after both low-dose and high-dose irradiation by Western blot analysis. Second, fracture healing was evaluated via histology and gene expression after single-dose X-ray irradiation, and low-dose X-ray irradiation accelerates fracture healing of closed femoral fractures in rats. In low-dose X-ray irradiated fractures, an increase in proliferating cell nuclear antigen (PCNA)-positive cells, cartilage formation and fracture calluses was observed. In addition, we observed more rapid completion of endochondral and intramembranous ossification, which was accompanied by altered expression of genes involved in bone remodeling and fracture callus mineralization. Although the expression level of several osteoblast differentiation genes was increased in the fracture calluses of high-dose irradiated rats, the callus formation and fracture union were delayed compared with the control and low-dose irradiated fractures. These results reveal beneficial effects of low-dose irradiation, including the stimulation of osteoblast proliferation, differentiation and fracture healing, and highlight its potential translational application in novel therapies against bone-related diseases.

Lateral patellar translation effects after arthroscopic partial meniscectomy of torn discoid lateral meniscus.

OBJECTIVE: To investigate the effects of arthroscopic partial meniscectomy of torn discoid lateral meniscus on patellar tracking. METHODS: In all, 112 patients (112 knees) who underwent arthroscopic partial meniscectomy participated in the study. All subjects were examined with standing weight-bearing magnetic resonance imaging (MRI) preoperatively and one month postoperation. Axial-plane images through the maximum width of the patella and the maximum dorsal area of the femoral condyles were superimposed and the bisect offset index used to quantify patellar translation. Differences between pre- and postoperation in the bisect offset indexes were calculated and compared by Student's paired t-test. P < 0.05 was considered statistically significant. RESULTS: Before surgery, the mean bisect offset index was 0.574 (0.437-0.692). One month postoperation, the mean bisect offset index was 0.622 (0.510-0.801). The postoperation bisect offset index increased by an average of 0.048 (-0.018 to 0.129) compared with the preoperation value; this difference is statistically significant result (t = 18.33, P < 0.01). CONCLUSION: After arthroscopic partial meniscectomy, the patella translates more lateral to the femoral trochlear groove. These results suggest that arthroscopic partial meniscectomy may result in patellar maltracking.

Activation of AMPK protects against hydrogen peroxide-induced osteoblast apoptosis through autophagy induction and NADPH maintenance: new implications for osteonecrosis treatment?

Elevated hydrogen peroxide (H2O2) causes osteoblast dysfunction and apoptosis, serving as an important contributor to the development of osteonecrosis. Here we aimed to understand the role of AMP-activated protein kinase (AMPK) in the process. We observed a high level of AMPK activation in surgery isolated patients' osteonecrosis tissues. In cultured osteoblastoma MG63 cells, H2O2 stimulation induced significant AMPK activation, oxidative stress, cell death and apoptosis. Inhibition of AMPK by its inhibitor (compound C) or by shRNA-mediated knockdown dramatically enhanced H2O2-induced MG63 cell apoptosis, while over-expression of AMPK in HEK-293 cells alleviated H2O2-induced cell damage. These results confirmed that H2O2-activated AMPK is pro-cell survival. We observed that H2O2 induced protective autophagy in MG63 cells, and AMPK-dependent Ulk1 activation and mTORC1 (mTOR complex 1) inactivation might involve autophagy activation. Further, AMPK activation inhibited H2O2-induced oxidative stress, probably through inhibiting NADPH (nicotinamide adenine dinucleotide phosphate) depletion, since more NADPH depletion and oxidative stress were induced by H2O2 in AMPK deficient MG63 cells. Finally, we observed a significant AMPK activation in H2O2-treated primary cultured and transformed (MC3T3-E1) osteoblasts, and AMPK inhibitor compound C enhanced death by H2O2 in these cells. Based on these results, we concluded that H2O2-induced AMPK activation is pro-survival and anti-apoptosis in osteoblasts. Autophagy induction and NADPH maintenance are involved in AMPK-mediated pro-survival effects. AMPK might represent a novel molecular target for osteonecrosis treatment.

Inhibition of the mammalian target of rapamycin leads to autophagy activation and cell death of MG63 osteosarcoma cells.

It has been well documented that the inhibition of the mammalian target of rapamycin (mTOR) induces autophagy in proliferative cells. Therefore, mTOR inhibitors have been proposed for the treatment of cancer. As autophagy plays significant roles in tumor cell survival, the present study aimed to investigate the contribution of autophagy activation to the antitumor effects of cis-diamminedichloroplatinum (CDDP). An MTT assay was used to determine the cytotoxic effects of rapamycin on MG63 osteosarcoma cells. The cell cycle was assessed using a flow cytometry analysis subsequent to staining the DNA with propidium iodide. The mitochondrial membrane potential (Δψ) was measured using the fluorescent probe, JC-1. Western blot analysis was used to determine the expression of the proteins that are involved in apoptosis and autophagy, including p53, p62, light chain 3 (LC3) and Beclin-1. The viability of the MG63 cells was inhibited following rapamycin or CDDP treatment. The mitochondrial Δψ collapsed following treatment with rapamycin or CDDP. Rapamycin induced cell death and enhanced the effects of the induction of MG63 cell death by CDDP. Western blot analysis detected the induced expression of the p53 and Beclin-1 proteins and the autophagic proteins, LC3 and p62. Rapamycin was observed to induce the death of cancer cells through apoptotic and autophagic mechanisms. Rapamycin may enhance the effects of the activation of autophagy and the induction of apoptosis by CDDP.