Enhancement of Bone Repair in Diabetic Rats with Metformin-Modified Silicified Collagen Scaffolds.

Regenerating bone defects in diabetic rats presents a significant challenge due to the detrimental effects of reactive oxygen species and impaired autophagy on bone healing. To address these issues, a metformin-modified biomimetic silicified collagen scaffold is developed utilizing the principles of biomimetic silicification. In vitro and in vivo experiments demonstrated that the scaffold enhanced bone tissue regeneration within the diabetic microenvironment through the release of dual bio-factors. Further analysis reveals a potential therapeutic mechanism whereby these dual bio-factors synergistically promoted osteogenesis in areas of diabetic bone defects by improving mitochondrial autophagy and maintaining redox balance. The present study provides critical insights into the advancement of tissue engineering strategies aimed at bone regeneration in diabetic patients. The study also sheds light on the underlying biological mechanisms.

Fixation versus Excision of Osteochondral Fractures after Patellar Dislocations in Adolescent Patients: A Retrospective Cohort Study.

BACKGROUND: Patellar dislocation is one of the most common knee injuries in the adolescent population. It is often combined with osteochondral fracture. The purpose of this study was to compare the outcomes between fixation and excision of osteochondral fractures not involving the bearing surface in adolescent patients with patellar dislocations. METHODS: Patients who underwent surgery for osteochondral fracture following patellar dislocation in our institution from 2007 to 2014 were retrospectively evaluated. Visual analog scale (VAS) of pain and the International Knee Documentation Committee (IKDC) form were used to assess knee pain and function at follow-up. Patient satisfaction was evaluated. Differences in the values of variables among groups were assessed using t-test if equal variance or Mann-Whitney U-test if not equal variance. The Pearson's Chi-square test was applied for dichotomous variables if expected frequency was >5 or Fisher's exact test was applied if not. A value of P < 0.05 was considered statistically significant. RESULTS: Forty-three patients were included, with the average age of 14.1 ± 2.3 (range, 9.0-17.0) years. Nineteen underwent fixation of osteochondral fractures and 24 did not. The average follow-up time was 28 ± 10 months. There was no significant difference in age, gender, follow-up time, causes of injury, times of dislocation, and location of osteochondral fracture between fixation and excision groups. The fixation group had a significantly longer surgery time (82 ± 14 min) and larger size of osteochondral fracture (2.30 ± 0.70 cm2) than the excision group (43 ± 10 min, 1.88 ± 0.62 cm2, respectively, t = 10.77, P < 0.01 and t = 0.84, P < 0.05). At the last follow-up, the average IKDC score in the fixation group (82.52 ± 8.71) was significantly lower than that in the excision group (89.51 ± 7.19, t = 2.65, P < 0.01). There was no significant difference in VAS of pain and patients' satisfaction. There were 7 (16%) patients with recurrent dislocation. CONCLUSION: Excision of osteochondral fractures has equivalent or better outcomes compared to fixation in adolescent patients with patellar dislocations when these fractures do not involve the bearing surface.

Anatomical Knee Variants in Discoid Lateral Meniscal Tears.

BACKGROUND: Discoid lateral meniscus was a common meniscal dysplasia and was predisposed to tear. There were some anatomical knee variants in patients with discoid lateral meniscus. The aim of this study was to analyze the relationship between anatomical knee variants and discoid lateral meniscal tears. METHODS: There were totally 125 cases of discoid lateral meniscus enrolled in this study from February 2008 to December 2013. Eighty-seven patients who underwent arthroscopic surgery for right torn discoid lateral meniscus were enrolled in the torn group. An additional 38 patients who were incidentally identified as having intact discoid lateral menisci on magnetic resonance imaging (MRI) findings were included in the control group. All patients were evaluated for anatomical knee variants on plain radiographs, including lateral joint space distance, height of the lateral tibial spine, height of the fibular head, obliquity of the lateral tibial plateau, squaring of the lateral femoral condyle, cupping of the lateral tibial plateau, lateral femoral condylar notch, and condylar cutoff sign. The relationship between anatomical variants and meniscal tear was evaluated. These anatomical variants in cases with complete discoid meniscus were also compared with those in cases with incomplete discoid meniscus. RESULTS: There were no significant differences between the two groups in lateral joint space distance (P = 0.528), height of the lateral tibial spine (P = 0.927), height of the fibular head (P = 0.684), obliquity of the lateral tibial plateau (P = 0.672), and the positive rates of squaring of the lateral femoral condyle (P = 0.665), cupping of the lateral tibial plateau (P = 0.239), and lateral femoral condylar notch (P = 0.624). The condylar cutoff sign was significantly different between the two groups, with the prominence ratio in the torn group being smaller than that in the control group (0.74 ± 0.11 vs. 0.81 ± 0.04, P = 0.049). With the decision value of the prominence ratio (0.78) in predicting discoid lateral meniscal tear, the sensitivity and specificity of the cutoff sign were 66% and 71%, respectively. There were no significant differences in radiographic variants between the complete and incomplete discoid lateral meniscal groups. CONCLUSIONS: The condylar cutoff sign observed on the tunnel view of the radiograph is helpful in predicting meniscal tear in adult patients with discoid lateral meniscus. As for these patients, further MRI test is recommended.

Relationship between Inflammatory Response and Estimated Complication Rate after Total Hip Arthroplasty.

BACKGROUND: After total hip arthroplasty (THA), there is a noteworthy inflammatory response. The inflammatory response is associated with postoperative recovery and complications. However, there had been few reports on the relationship between inflammatory response and postoperative complication rate. The aim of the present study was to investigate early inflammatory response in the first 3 days after THA, and to identify the relationship between inflammatory response and estimated complication rate after surgery. METHODS: It was a prospective, nonrandomized cohort study. There were 148 patients who underwent unilateral THA in our hospital enrolled. Blood samples were collected preoperatively in the morning of the surgery and at 24, 48, and 72 h after surgery. C-reactive protein (CRP) and interleukin-6 (IL-6) in peripheral blood were measured. The modified physiological and operative severity score for the enumeration of the morbidity (POSSUM) was recorded pre- and intra-operatively. Based on the score, estimated complication rate was calculated. Harris score was used to assess hip function before and after surgery. RESULTS: IL-6 levels reached the peak at 24 h after surgery and CRP at 48 h. After that, both of the levels decreased. The mean Harris scores significantly increased from 41.62 ± 23.47 before surgery to 72.75 ± 9.13 at 3 days after surgery. The Harris scores after surgery did not have a significant relation with either IL-6 or CRP peak levels (P = 0.165, P = 0.341, respectively). Both CRP and IL-6 peak levels significantly and positively correlated with estimated complication rate after surgery. The estimated complication rate calculated using the POSSUM system was 43 cases of 148 patients. Actually, there were only 28 cases that were observed to get postoperative complications during hospitalization. However, there was no significant difference between estimated and observed complication rates (P = 0.078). In the group with complications, the CRP and IL-6 peak levels were significantly higher than those in the group without complications (both P< 0.001). CONCLUSIONS: There were significantly positive relationships between both peak levels of CRP and IL-6 and estimated complication rate after THA. Inflammatory response could predict the incidence of complications after THA.

Roles of leptin in bone metabolism and bone diseases.

Adipose tissue has been more accepted as an active contributor to whole body homeostasis, rather than just a fat depot, since leptin, a 16 kDa protein, was discovered as the product of the obese gene in 1994. With more and more studies conducted on this hormone, it has been shown that there is a close relationship between adipose tissue and bone, which have important effects on each other. Bone is the source of many hormones, such as osteocalcin, that can affect energy metabolism and then the anabolism or catabolism of fat tissue. In contrast, the adipose tissue synthesizes and releases a series of adipokines, which are involved in bone metabolism through direct or indirect effects on bone formation and resorption. Interestingly, leptin, one of the most important cytokines derived from fat tissue, seems to account for the largest part of effects on bone, through direct or indirect involvement in bone remodeling and by playing a significant role in many bone diseases, such as osteoporosis, osteoarthritis, rheumatic arthritis, bone tumors and even fractures. In this review, we will discuss the progress in leptin research, particularly focusing on the roles of leptin in bone diseases.