Evaluation of the Healing Status of Lateral Ankle Ligaments 6 Weeks After an Acute Ankle Sprain

Abstract

We aimed to investigate whether there is clinical and MRI evidence of healing of lateral ligaments 6 weeks after acute lateral ankle sprain (LAS). We prospectively enrolled 18 participants (age 32.7 ± 7.5 years) who sustained an acute LAS and underwent conservative treatment. An ankle MRI was acquired up to 48 hours and 6 weeks following the LAS. A partial tear of the anterior talofibular ligament (ATFL) was observed in 10/18 and a complete tear in 8/18 of the patients. The calcaneofibular ligament (CFL) was partially torn in 11/18 and completely torn in 1/18 of the patients. The healing status, intensity, and thickness of the ligaments, Anterior Drawer Test (ADT), and FAOS scale were assessed. A control group (CG) was composed by 17 participants (age 40 ± 13.9 years). Six weeks after the LAS, 89% of the participants presented MRI evidence of ATFL healing. The repaired ATFL was thicker in comparison with the CG (p < .001). The cut-off of 2.5 mm for ATFL thickness in the 6th week maximized sensitivity (62.5%) and specificity (100%). CFL and PTFL presented 94% and 100% of healing signs, respectively. In the 6th week, 11/18 (61%) participants showed mild residual instability and a mean FAOS of 80 ± 11. The MRI revealed signs of the repair process in 89% of ATFL and 94% of CFL tears, 6 weeks after a moderate or severe LAS. The MRI findings were concomitant with enhancements in mechanical ankle stability and function.