Usually there is fall involving a blow to the front of the knee or perhaps a more serious injury such as a car accident. These injuries usually require a more significant level of trauma than a simple ACL tear.
The knee will usually swell and require the use of crutches.
The degree of the injury (whether it is minor and partial or complete and major) determines the recovery and whether surgical treatment is needed. Often there are other injuries to structures in and around the knee. Menisci can be torn; other ligaments can be injured.
The new internal bracing treatment systems such as Fibretape ( insert R) have allowed an entirely new approach to the management of these injuries.
Whilst we use to treat a number of these injuries without surgery, there is an increasing trend to surgical reconstruction EARLY in the post-injury period.
For minor injuries this may well be the treatment of choice, combined with physiotherapy and a brace for a short period of time.
Either internal bracing or perhaps a formal PCL reconstruction may be required.