About this video
Last updated: 3 November 2026
The video explains that a partial anterior cruciate ligament (ACL) tear means some ACL fibres remain intact, and that while an MRI scan shows what the ligament looks like, it does not always show how well the knee functions. Published studies also note that an MRI cannot always confirm whether a tear is partial, which is another reason the examination matters. Some partially torn ACLs remain stable with rehabilitation, while others continue to give way during movement. A partially torn ACL can go on to tear completely over time; in a study of active people under 30, this happened more often in those aged 20 or younger and in those playing pivoting contact sports, which is one reason for ongoing monitoring.
Key points
- Clinical examination assesses whether the remaining fibres provide enough functional stability during movement.
- Alongside the examination, the video lists three factors that guide decisions: age and activity level, sporting goals, and whether instability affects everyday function.
- Some patients are managed with structured rehabilitation and ongoing monitoring, while those with persistent instability or high-demand sporting goals may be considered for ACL reconstruction if non-operative care is not sufficient.
- The video notes that the MRI scan is one piece of information alongside how the knee performs and what activities the person hopes to return to.
Questions this video answers
Does a partial ACL tear on an MRI always need surgery?
The video says not necessarily. An MRI shows what the ligament fibres look like, and clinical examination is needed to test whether the remaining fibres keep the knee stable during movement. Some people are managed with structured rehabilitation and monitoring, while others with ongoing giving way or high-demand sporting activities may be considered for ACL reconstruction if non-operative care is not sufficient.
What factors help decide between rehabilitation and surgery for a partial ACL tear?
Beyond the MRI and physical examination of knee stability, the video highlights three factors: age and activity level, sporting goals, and whether instability is affecting everyday function.