A Mouse Model of Ankle-Subtalar Complex Joint Instability.

Ankle sprains are perhaps the most common sports injuries in daily life, often resulting in instability of the ankle-subtalar complex joint (ASCJ), and can eventually lead to post-traumatic osteoarthritis (PTOA) in the long term. However, due to the complexity of the injury mechanism and the clinical manifestations, such as ecchymosis, hematoma, or tenderness in the lateral foot, there is no clinical consensus on diagnosing and treating ASCJ instability. Since the musculoskeletal structure of the bones and ligaments of the mouse hindfoot is comparable to that of humans, an animal model of ASCJ instability in mice was established by the transection of ligaments around the ASCJ. The model was well-validated through a series of behavioral tests and histological analyses, including a balance beam test, a footprint analysis (an assessment of exercise level and balance ability in mice), a thermal nociception assessment (an assessment of foot sensory function in mice), micro-computed tomography (CT) scanning, and section staining of the articular cartilage (an assessment of articular cartilage damage and degeneration in mice). The successful establishment of a mouse model of ASCJ instability will provide a valuable reference for clinical research on the injury mechanism and result in better treatment options for ankle sprain.