Objective: Adjacent vertebral fractures (AVFs) are frequent in the early postoperative period following balloon kyphoplasty (BKP) for osteoporotic vertebral fractures (OVFs); however, the mechanism remains unclear. This study aimed to elucidate the mechanism of AVF by comparing early radiographic changes in patients with and without AVF. Methods: Sixty-three patients who underwent BKP within 60 days of OVF onset and were followed for at least 3 months postoperatively were included. Patients were divided into AVF and non-AVF groups. Comparative analyses were conducted for demographics, volume of bone cement injected, and radiological assessments presurgery, postsurgery, 1 and 2 weeks postoperatively, and at final follow-up. Key radiographic parameters, including vertebral kyphotic angle (VKA) and anteroposterior vertebral height ratio (A/P ratio), were evaluated between the groups. Results: AVF occurred in 8 out of 63 patients (12.7%). Demographics and bone cement volume showed no significant differences between groups. Radiographic analysis revealed earlier VKA deterioration in the non-AVF group, with significant differences at 2 weeks postoperatively. In the AVF group, VKA and the A/P ratio showed more pronounced changes from preoperative to postoperative measurements. The change in the A/P ratio was significantly greater in the AVF group than in the non-AVF group. Conclusions Vertebral correction deteriorated earlier in the non-AVF group, while BKP resulted in a more substantial correction of vertebral bodies in the AVF group. These findings suggest that the mechanical stability achieved by BKP may contribute to the differential progression of AVF, highlighting the need for tailored postoperative management.

BACKGROUND: Irisin is a myokine implicated in lipid and glucose metabolism. The objective of this study is to examine the effect of a body weight reduction on the serum irisin level and physical indicators in obese Japanese patients without diabetes. METHODS: The subjects were 22 patients (male/female, 5/17; age, 46.1±16.0 years; body mass index [BMI], 36.9±5.0 kg/m²) who completed a 6-month body weight reduction program at our clinic. The program included diet, exercise therapy and cognitive behavioral therapy. Blood parameters, body composition, exercise tolerance, homeostasis model assessment of insulin resistance (HOMA-IR), and serum irisin were determined before and after intervention, and relationships among changes in these data were examined. RESULTS: There were significant decreases in body weight and BMI after the intervention. Irisin before the intervention was significantly positively correlated with HOMA-IR (r=0.434, P<0.05). The mean irisin level showed no significant change after the intervention in all participants. However, improvements in % body fat, subcutaneous fat area, triglycerides, and fasting glucose were significantly greater in patients with an increase in irisin compared to those with a decrease in irisin after the intervention. Patients with an increase in irisin also had significantly lower fasting insulin (9.7±4.8 vs. 16.4±8.2, P<0.05) and HOMA-IR (2.2±1.1 vs. 3.7±1.6, P<0.05) after the intervention, compared to patients with a decrease in irisin. CONCLUSION: Body weight reduction did not alter irisin levels. However, irisin may play important roles in fat and glucose metabolism and insulin resistance, and the effects of body weight reduction on irisin kinetics may be a key for obesity treatment.
Adipose Tissue ; Asian Continental Ancestry Group ; Body Composition ; Body Mass Index ; Body Weight* ; Cognitive Therapy ; Diet ; Exercise Therapy ; Exercise Tolerance ; Fasting ; Glucose ; Homeostasis ; Humans ; Insulin ; Insulin Resistance ; Kinetics ; Metabolism ; Obesity ; Subcutaneous Fat ; Triglycerides