Incidence and trend of antiresorptive agent-related osteonecrosis of the jaw from 2016 to 2020 in Kure, Japan.

We investigated the incidence/trend of osteonecrosis of the jaw by antiresorptive agent dose over a 5-year period in Kure city, Japan. The incidence was 24 times higher among osteoporosis patients with low-dose agents and 421 times higher among cancer patients with high-dose agents than in the population without agents. PURPOSE: We launched the registry system of osteonecrosis of the jaw (ONJ) cases in 2015 to investigate the trend in ONJ incidence. The purpose of our study was to estimate the ONJ incidence among patients with antiresorptive agent use by dosage and people without antiresorptive agent use in Kure and its trend from 2016 to 2020. METHODS: From 2016 to 2021, 98 eligible ONJ patients were enrolled. Medication-related ONJ (MRONJ) was diagnosed based on the American Association of Oral and Maxillofacial Surgeons criteria. The annual number of those with and without antiresorptive agents was obtained from the claims database. Antiresorptive agents used for cancer and osteoporosis patients were defined as high- and low-dose medications, respectively. RESULTS: The annual incidence of high-dose MRONJ was 2305.8 per 100,000 and that of low-dose MRONJ was 132.5 per 100,000, while the ONJ incidence among people without antiresorptive agents was 5.1 per 100,000. The incidence ratio was 23.6 (p < 0.001, 95% confidence interval (CI) 13.3-41.8) among osteoporosis patients who used low-dose antiresorptive agents and 420.6 (p < 0.001, 95% CI 220.8-801.4) among cancer patients who used high-dose agents compared with people who did not use these agents. MRONJ incidence increased from 2016 to 2020, but the incidence of high-dose MRONJ decreased, although this was nonsignificant. CONCLUSION: We demonstrated the incidence and trend of ONJ by antiresorptive agent dose over a 5-year period in Kure after launching the multiprofession study. This collaborative study for the early detection and prevention of ONJ will continue.

Association between physical function and parameters of hip structural analysis in patients with hip fracture.

OBJECTIVES: The current study sought to investigate whether physical function and activity were associated with hip structural analysis (HSA) parameters on the non-fracture side of patients with hip fractures. METHODS: Participants were patients with unilateral hip fracture treated by surgery. HSA of the proximal femur was conducted based on dual-energy x-ray absorptiometry data. HSA parameters in the narrow neck region included cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (SM), and buckling ratio (BR). Hierarchical multiple regression analysis was conducted to identify predictors of HSA. RESULTS: Except for the adjustment variables, age, gender and BMI, other variables were extracted. Hierarchical multiple regression analysis (standardised partial regression coefficients) identified movement control during one-leg standing on the non-fractured side (0.15) as factors associated with CSA. Hierarchical multiple regression analysis (standardised partial regression coefficients) identified hand grip (0.12, 0.23) as factors associated with CSMI and SM, respectively. Hierarchical multiple regression analysis (standardised partial regression coefficients) identified presence of steroid (0.23) and cerebrovascular disease (0.19) as factors associated with BR. The coefficients of determination adjusted for degrees of freedom (R2) were 0.545, 0.331, 0.401, and 0.148 for CSA, CSMI, SM, and BR, respectively. CONCLUSIONS: Our results indicate that movement control during 1-leg standing and muscle strength may be important for maintaining and improving bone strength.

Improvement of muscle quality assessed using the phase angle is influenced by recovery of knee extension strength in patients with hip fractures.

BACKGROUND AND AIMS: Studies reported that knee extension strength on the operated side in patients with hip fractures was not recovered to the level on the non-operated side 6 months after surgery or later. In a cross-sectional study, we revealed that a reduction in isometric knee extension muscle strength on the operated side in patients with hip fractures approximately 6 months after surgery was associated with not only a reduction in skeletal muscle mass but also a reduction in muscle quality, characterized by a reduction in the phase angle (PhA). Furthermore, the mechanisms of knee extension strength improvement can be clarified in more detail using the minimal significant change as the index of recovery. However, no longitudinal studies have examined the factors for knee extension strength improvement based on the minimal significant change in patients with hip fractures 6 months after surgery. This study aimed to longitudinally examine the factors influencing the recovery of knee extension strength based on the minimal significant change in patients with hip fractures between 2 weeks and approximately 6 months after surgery. METHODS: In this study, the outcomes used were basic and medical information, PhA, skeletal muscle index (SMI), pain, one-leg standing time, movement control during one-leg standing, and walking speed. For PhA, SMI, pain, one-leg standing time, movement control during one-leg standing, and walking speed, the amount of change was calculated by subtracting the data at 2 weeks from the data at 6 months. Group classification was determined by dividing the patients into two groups using a previous study as a reference: recovery group if the knee extension strength value approximately 6 months after surgery minus that 2 weeks after surgery was ≥3.3 kgf and non-recovery group if the value was <3.3 kgf. Logistic regression analysis was performed to explore the association between the recovery and non-recovery groups. RESULTS: The recovery group contained 55 patients, while the non-recovery group comprised 35 patients. The only significant factor associated with knee extension muscle strength in the recovery group was the amount of change in PhA. The odds ratio for the amount of change in PhA was 2.26. The discrimination rate of the model was 62.5%. CONCLUSIONS: Our results suggest that recovery of knee extension strength in patients with hip fractures after surgery was mainly because of improvements in muscle quality, not improvements in muscle mass or pain.

The effect of anterior support screw (AS2) in unstable femoral trochanteric fractures: A multicenter randomized controlled trial.

OBJECTIVES: This study was conducted to verify the effectiveness of Anterior Support Screw (AS2) for unstable femoral trochanteric fractures. DESIGN: A multicenter, prospective, randomized controlled trial SETTING: This study was conducted across 15 academic medical centers in Japan PATIENTS/PARTICIPANTS: We enrolled 240 cases of femoral trochanteric fractures with posterior crushing and intramedullary displacement of proximal bone fragments across 15 institutions in Japan. INTERVENTION: All patients were subjected to a reduction in which the anterior cortex was brought into contact. The patients were randomly assigned to the anterior support screw group (AS2 group) and the non-screw group (control group). MAIN OUTCOME MEASUREMENTS: Two computed-tomography (CT) scans were taken immediately after surgery and early postoperative period (day 14-21) to investigate the reduction loss rate of the anterior cortex and sliding distances in the early postoperative period. RESULTS: The reduction loss rate was 4.5 % in the AS2 group and 16.8 % in the control group, indicating a significantly lower reduction loss rate in the AS2 group (p = 0.003). The average sliding distance was 1.8 mm in the AS2 group and 2.8 mm in the control group, indicating a significantly shorter sliding distance in the AS2 group (p < 0.0001). CONCLUSION: Adding a screw in front of the intramedullary nail significantly reduces reduction loss, and maintains anterior bony contact. This study also showed that these screws suppress the sliding distance during the postoperative period. LEVEL OF EVIDENCE: Therapeutic Level I.

Not only muscle mass but also muscle quality is associated with knee extension muscle strength in patients with hip fractures.

Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA. PURPOSE: This study aimed to assess the relationship between isometric knee extension muscle strength on the operated or nonoperated sides and PhA in patients with hip fractures at approximately 6 months postoperatively. METHODS: This study was a cross-sectional study. Skeletal muscle index (SMI), PhA, knee extension muscle strength on the operated and nonoperated sides, and other physical function variables were assessed at approximately 6 months postoperatively. To identify predictors of knee extension muscle strength on the operated and nonoperated sides, hierarchical multiple regression analysis was performed. RESULTS: A total of 90 patients with hip fractures were included (mean age, 80.1 ± 6.9 years). SMI (0.45) and PhA on the operated side (0.27) were the significant associated factors extracted for isometric knee extension muscle strength on the operated side (standardized partial regression coefficients), independent of age, sex, and body mass index (BMI). Movement control during one-leg standing on the nonoperated side (0.26), SMI (0.32), and PhA on the nonoperated side (0.40) were the significant associated factors extracted for isometric knee extension muscle strength on the nonoperated side, independent of age, sex and BMI. CONCLUSIONS: Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures at approximately 6 months postoperatively was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

Incidence of clinical vertebral fractures and hip fractures of the elderly (65 years or over) population-large-scale data analysis using claim database in Kure City, Hiroshima, Japan.

Using the claim database, we investigated the incidence rate of clinical vertebral fractures per 1,000 in the elderly residents, over 65 years of age, in Kure city. The incidence rate, of clinical vertebral fractures, was 15.58 (7.29 male, 21.17 female, 2.90 female/male ratio). PURPOSE: To elucidate the incidence of clinical vertebral and hip fractures using the claim database, in those over 65 years of age in Kure city, and to compare with the previous reports. METHODS: We used, for residents in 2015, the medical care information of the National Health Insurance or Senior Elderly Care System in Kure City (Hiroshima Prefecture, Japan). Those with vertebral fractures as disease name, and either treatment/operation/hospitalization were defined as clinical vertebral fractures. Among the claim database, we extracted the clinical vertebral fracture and investigated the number of occurrences and the incidence rate per 1,000. We also investigated the incidence rate of hip fractures and compared those to the clinical vertebral fractures. RESULT: The incidence rate of clinical vertebral fractures of the elderly population (65 years or over) per 1,000 was 15.58 (7.29 male, 21.17 female, 2.90 female/male ratio). In both men and women, the incidence rate increased with aging. The incidence rate of hip fractures per 1,000 was 9.17 (3.55 male, 12.96 female, 3.65 male/female ratio). Clinical vertebral fractures were more frequent than hip fractures, and the ratio of incidence rate of vertebral fractures to hip fractures was 1.70 (male, 2.05, female, 1.63). For both fractures, the incidence rate increases with age, apart from the women where the incidence of vertebral fracture reduces slightly in the older age group CONCLUSION: This is the first report that investigated the incidence rate of the clinical vertebral fractures using the claim database, which covered almost the whole number of 230,000 population area.

Resorption of apatite-wollastonite containing glass-ceramic and beta-tricalcium phosphate in vivo.

Apatite-wollastonite containing glass ceramic is considered to be difficult to resorb, but we experienced the disappearance of the porous type of Apatite-wollastonite glass ceramic particles . In this study, the resorption of porous apatite-wollastonite glass-ceramic implanted in the femurs of rabbits was investigated, and the process was compared with beta-tricalcium phosphate, a resorbable ceramics. Porous apatite-wollastonite glass-ceramic (70, 80, and 90% porosity) and beta-tricalcium phosphate (75% porosity) were implanted in the femurs of Japanese white rabbits. Samples were harvested and examined 0, 4, 8, 12, 24 and 36 weeks after implantation. Quantitative analysis of the radiographic and histologic findings was performed with NIH Image software. Radiographic examination demonstrated that the radiopacity and size of the porous apatite-wollastonite glassceramic cylinders decreased gradually after implantation. Histologic examination revealed that the surface area of the apatite-wollastonite glass-ceramic cylinders decreased continuously, and approached 20% of the original area 36 weeks after implantation. However, the resorption rate of porous apatite-wollastonite glass-ceramic was slower than that of beta-tricalcium phosphate. Toluidine blue staining showed abundant new bone formation on the surface of the apatite-wollastonite glassceramic matrix. Considering its mechanical strength, gradual resorption characteristics, and good osteochonductive activity, porous apatite-wollastonite glass-ceramic appears to be a suitable artificial bone substitutes.