T -Mapping evaluation of early cartilage alteration of talus for chronic lateral ankle instability with isolated anterior talofibular ligament tear or combined with calcaneofibular ligament tear.

PURPOSE

To quantitatively evaluate the cartilage alteration of talus for chronic lateral ankle instability (LAI) with isolated anterior talofibular ligament (ATFL) tear and combined ATFL and calcaneofibular ligament (CFL) tear using T -mapping at 3.0T.

MATERIALS AND METHODS

In all, 27 patients including 17 with isolated ATFL tear and 10 with ATFL+CFL tear, and 21 healthy subjects were recruited. All participants underwent T -mapping scan at 3T and patients completed American Orthopaedic Foot and Ankle Society (AOFAS) scoring. The total talar cartilage (TTC) was segmented into six compartments: medial anterior (MA), medial center (MC), medial posterior (MP), lateral anterior (LA), lateral center (LC), and lateral posterior (LP). The T value of each compartment was measured from T -mapping images. Data were analyzed with one-way analysis of variance (ANOVA), Student's t-test, and Pearson's correlation coefficient.

RESULTS

The T values of MA, MC, MP, TTC in the ATFL group and MA, MC, MP, LC, LP, TTC in the ATFL+CFL group were higher than those in the control group (P < 0.05). Moreover, the T values of MC, MP, LC, and TTC in the ATFL+CFL group were higher than those in the ATFL group (P < 0.05). The T values of MA in both patient groups were negatively correlated with AOFAS scores (r = -0.596, r = -0.690, P < 0.05).

CONCLUSION

Chronic LAI with ATFL tear had a trend of increasing cartilage T values in talar trochlea, mainly involving medial cartilage compartments. Chronic LAI with ATFL+CFL tear might result in higher T values in a much larger cartilage region than with ATFL tear. MA could be the main cartilage compartment that may affect the patient's clinical symptoms.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:69-77.