Rationale and objectives: This study aims to quantitatively compare T2* measurements of the talar cartilage between chronic lateral ankle instability (LAI) patients with lateral ligament injury and healthy volunteers, and to assess the association of T2* value with American Orthopedic Foot and Ankle Society (AOFAS) score.
Materials and methods: Nineteen consecutive patients with chronic LAI (LAI group) and 19 healthy individuals (control group) were enrolled. Biochemical magnetic resonance examination of the ankle was performed in all participants using three-dimensional gradient-echo T2* mapping. Total talar cartilage was divided into six subcompartments, including medial anterior (MA), central medial, medial posterior, lateral anterior, central lateral (LC), and lateral posterior regions. T2* values of respective cartilage areas were measured and compared between the two groups using Student t test. AOFAS scoring was performed for clinical evaluation. Then, the association of T2* value with AOFAS score was evaluated by Pearson correlation.
Results: The T2* values of total talar cartilage, as well as MA and LC cartilage compartments, in the chronic LAI group were significantly higher than control values (P < .001, P = .039, and P = .014, respectively). Furthermore, the T2* value of MA in the chronic LAI group was negatively correlated with AOFAS score (r = -0.8089, P < .001).
Conclusions: Chronic LAI with lateral ligament injury may have a causal connection with early cartilage degeneration in the ankle joint, especially in MA and LC cartilage compartments, as assessed by quantitative T2* measurements. The clinical score correlates highly with T2* value of the MA cartilage compartment, indicating that MA may be the principal cartilage area conferring clinical symptoms.
Keywords: Chronic lateral ankle instability (LAI); T2* mapping; cartilage degeneration.
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