PUD@HA/PEEK Scaffold Induces Subchondral Bone Regeneration to Repair Osteochondral Defect in Rabbits.

Osteochondral defects (OCDs) pose a significant challenge in clinical practice, and recent advancements in their repair indicate that satisfying subchondral bone repair may be critical for this. Herein, a series of hydroxyapatite/poly(ether ether ketone) (HA/PEEK) scaffolds were fabricated with varying mass percentages (0, 20, 30, and 40%) to induce subchondral bone regeneration. Subsequently, an optimal scaffold with 40% HA/PEEK was selected to establish osteochondral scaffolds with poly(ether urethane) urea-Danshensu (PUD) for repairing the OCD. The material characteristics of HA/PEEK and PUD were investigated using scanning electron microscopy, tensile, swelling, and fatigue tests, and cytological experiments. The effects of serial HA/PEEK scaffolds on subchondral bone repair were then assessed by using microcomputed tomography, hard tissue slicing, and histological staining. Furthermore, the optimal 40% HA/PEEK scaffold was used to develop osteochondral scaffolds with PUD to observe the effect on the OCD repair. HA/PEEK materials exhibited an even HA distribution in PEEK. However, when composited with HA, PEEK exhibited inferior mechanical strength. 40%HA/PEEK scaffolds showed an optimum effect on in vivo subchondral bone repair. Cartilage regeneration on 40%HA/PEEK scaffolds was pronounced. After PUD was introduced onto the HA/PEEK, the PUD@40%HA/PEEK scaffold produced the expected effect on the repair of the OCD in rabbits. Therefore, achieving satisfactory subchondral bone repair can benefit surficial cartilage repair. The PUD@40%HA/PEEK scaffold could induce subchondral bone regeneration to repair the OCD in rabbits and could provide a novel approach for the repair of the OCD in clinical practice.

The epidemic of stroke mortality attributed to high body mass index in mainland China: Current trends and future prediction.

Background: High body mass index (BMI) is an important risk factor for stroke. The aim of this study was to assess the long-term trend of high BMI-attributed stroke mortality and make projections through 2030. Methods: Data were extracted from the Global Burden of Disease Study 2019 and World Population Prospects 2019. An age-period-cohort framework was used in the analysis. Results: From 1990 to 2019, the age-standardized mortality rate (ASMR) of high BMI-attributed stroke among females decreased by 15.2%, while among males, it increased by 31.1%. All of the age groups studied showed an increasing pattern over the last 30 years in males, and in female, the age groups encompassing participants who were 25-69 years old showed a decreasing pattern. In the same birth cohort, high BMI-attributable stroke mortality rates increased exponentially with age in both sexes. For females, the period rate ratios (RR) showed a downward trend after 2000-2004, and the cohort RR also showed a downward trend after the birth cohort 1930-1934. For males, the period RR showed an upward trend, but this increase was halted in the most recent period, and the cohort RRs showed a monotonic increasing pattern. It was projected that the ASMR of high BMI-attributed stroke would decrease among females and increase among males in the near future and that the proportion of elderly individuals with death due to high BMI-attributed stroke was projected to increase. Conclusions: Over the last three decades, the high BMI-attributed stroke mortality rate decreased among females and increased among males, and these trends are projected to continue in the future. In addition, the proportion of elderly individuals with high BMI-attributed stroke mortality was projected to increase gradually in both men and women. More health-promoting efforts are needed, especially for elderly individuals and males.

Biomechanical Characteristics of the Femoral Isthmus during Total Hip Arthroplasty in Patients with Adult Osteoporosis and Developmental Dysplasia of the Hip: A Finite Element Analysis.

OBJECTIVE: This study investigated the underlying mechanisms of high fracture incidence in the femoral isthmus from a biomechanical perspective. METHODS: We retrospectively analyzed a total of 923 primary total hip arthroplasty (THA) patients and 355 osteoporosis (OP) patients admitted from January 2010 to January 2018. Through a series of screening conditions, 47 patients from each group were selected for inclusion in the study. The datasets on the unaffected side and affected side of the patients with unilateral developmental dysplasia of the hip (uDDH) were respectively classified as the normal group (Group I) and he tDDH group (Group II), and that of patients with osteoporosis were classified as the OP group (Group III). In this study, first, we collected computed tomography (CT) images and measured geometric parameters (inner and outer diameters) of the isthmus. Thereafter, to study biomechanical properties, we established six finite element models and calculated values of von Mises stress for each group with the methods of data conversion and grid processing. RESULTS: Compared with those of patients in the normal group, the values of the inner and outer diameters of femoral isthmus of patients in the DDH group were significantly lower (P < 0.001), while the inner diameters of patients in the OP group were significantly higher (P < 0.001) and the outer diameters of patients in the OP group showed no significant difference (P> 0.05). The cortical rates of patients in the normal group and the DDH group appeared insignificant (P > 0.05), and those of patients in normal group were significantly higher than those of patients in the OP group (P < 0.001). Moreover, patients in the DDH group showed a higher von Mises stress value than patients in the normal group (P < 0.001), but statistically speaking the values between patients in the OP and normal groups were insignificant (P > 0.05). CONCLUSIONS: The relatively shorter inner and outer diameters of the isthmus in DDH resulted in intensive von Mises stress under the torque of the hip location, and induced a high fracture incidence. However, in patients in the OP group, the geometric morphology exhibited no anatomical variation, and the fracture was not due to the intensity of von Mises stress.