There are two appearances of chronic ACL tears
- An ACL deficient knee
- A fibrosed reattached ACL
This is when there is no ACL seen. It occurs because the ACL completely ruptures and over time the torn fibres are resorbed. On MRI you see no ACL at all ( Image below Blue arrows point to absence of ACL)
A chronic tear that has fibrosed and reattached is much less common. Look for
- Fibres look continuous
- But alignment is abnormal
The two images in the next section demonstrate the MRI findings. Slide the Semi circle and arrow to demonstrate the findings.