Objective: To understand the characteristics of fall injuries among the elderly aged ≥60 years in Zhuhai City, Guangdong Province from 2018 to 2025, so as to provide evidence for the prevention and control of fall injuries in the elderly. Methods: Data on first-visit cases of fall injuries among the elderly aged ≥60 years in the outpatient and emergency departments of 3 national sentinel hospitals in Zhuhai City from 2018 to 2025 were collected through the injury surveillance module of the Guangdong Provincial Comprehensive Management Platform for Population Health Information. Descriptive analysis was conducted on the occurrence time, occurrence location, activity at the time and clinical characteristics of the fall injuryies. Results: A total of 22 145 cases of fall injuries among the elderly were reported from 2018 to 2025, including 8 365 male cases and 13 780 female cases, with a male-to-female ratio of 0.61∶1. The 60-<70 years age group had 10 087 cases (45.55%), the 70-<80 years age group had 6 633 cases (29.95%), and the ≥80 years age group had 5 425 cases (24.50%). More cases of fall injuries were reported in December and during 8∶00-10∶00, with 2 542 cases (11.48%) and 5 196 cases (23.46%), respectively. The main occurrence location of fall injuries was home, with 9 741 cases (43.99%). The main activity at the time off all injuries was leisure activity, with 11 284 cases (50.96%). The top 3 types of fall injuries were fracture/joint dislocation, craniocerebral injury and contusion/abrasion, with 7 530 cases (34.00%), 5 578 cases (25.19%) and 4 974 cases (22.46%), respectively. The leading type of fall injury in males was craniocerebral injury, with 2 340 cases (27.97%); while that in females was fracture/joint dislocation, with 5 281 cases (38.32%). The top 3 body parts of fall injuries were lower extremities, head and neck, and trunk, with 5 765 cases (26.03%), 5 421 cases (24.48%) and 5 406 cases (24.41%), respectively. The leading body part of fall injuries in males was head and neck, with 2 613 cases (31.24%); while that in females was lower extremities, with 3 687 cases (26.76%). The severity of fall injuries was mainly mild, with 15 004 cases (67.75%) . With the increase of age, the constituent ratio of head and neck as the body parts of fall injuries, as well as the constituent ratios of observation, referral and hospitalization as the outcomes of fall injuries among the elderly showed an upward trend (all P<0.05). Conclusions Fall injuries among the elderly in Zhuhai City peaked in December and during the morning period. Home was the main occurrence location of injuries. Females were key populations for prevention and control. Targeted prevention of adverse health outcomes induced by fall injuries is essential for advanced-age elderly populations.

BACKGROUND:As a dominant breed pig in southwest China,the southern Yunnan small-ear pig has been widely used as an experimental animal in the basic research of other disciplines,but there are still no reports on its application in anterior cruciate ligament reconstruction. OBJECTIVE:To establish a large animal model of the southern Yunnan small-ear pig with anterior cruciate ligament with autologous Achilles tendon was established. METHODS:Twenty adult female Yunnan small-ear pigs were equally randomized into two groups.In the autologous Achilles tendon group,the right knee anterior cruciate ligament was reconstructed with autologous Achilles tendon as a graft,while in the sham-operated group,a similar operation was performed on the right knee without any treatment of the anterior cruciate ligament.General conditions of each pig were observed and recorded before and 12 months after surgery.Ligaments and grafts were taken for gross observation and MAS scoring.Hematoxylin-eosin staining was performed to observe morphological characteristics of ligaments.The staining and arrangement of type I and type Ⅲ collagen were evaluated by immunohistochemistry.Transmission electron microscopy was used to observe the type,size,diameter,ratio,and distribution of collagen fibers in ligaments. RESULTS AND CONCLUSION:All animals had normal diet and activity,good wound healing,no obvious inflammatory reaction,no local purulent infection,and no significant changes in mental and urinary conditions compared with those before surgery.The reconstructed cruciate ligament of the knee was intact,with no stiffness and normal range of motion.Both the anterior drawer and Lachman tests were negative.Gross observation of the graft:12 months after surgery,the grafts was in good position,with good integrity,obvious tension,ligament color close to the original anterior cruciate ligament,and complete surface synovial coverage.Most of the intraarticular ligaments in the autologous Achilles tendon group were defined as MAS I type and a few were defined as MAS Ⅱ type.In the sham-operated group,the intraarticular ligament was defined as MAS I type.Hematoxylin-eosin staining indicated that,12 months after surgery,collagen fibers in the autologous Achilles tendon group began to appear bundled,isotropic,and uniformly arranged,with more obvious isotropic corrugations,and the nuclei were mainly linear or spindle-shaped,which were similar to those in normal anterior cruciate ligament tissue of the sham-operated group.Immunohistochemistry results indicated that,12 months after surgery,there was a higher expression of type I collagen and significantly less expression of type Ⅲ collagen in the reconstructed anterior cruciate ligament in the autologous Achilles tendon group.The degree of type I and type Ⅲ staining was similar in the two groups.Under the transmission electron microscope,the diameter,arrangement and density of collagen fibers in the reconstructed anterior cruciate ligament of the autologous Achilles tendon group were similar to those of the original anterior cruciate ligament at 12 months after surgery,indicating that the ligament remodeling process had been basically completed in the autologous Achilles tendon group at 12 months after surgery.Through a comprehensive evaluation of animal general conditions,ligament general view,MAS score,hematoxylin-eosin staining,immunohistochemistry,and transmission electron microscopy observation,we successfully established a large animal model of anterior cruciate ligament reconstruction using autogenous Achilles tendon in southern Yunnan small-ear pigs,with good morphological,histological and ultrastructural results.