You can go without a surgery if you are never going to get involved in high impact activities like running, jogging or field sports.
Also if your are overweight you should opt for a surgery
As you are young and might want to do the above activities more frequently than the elderly an orthopedic would advice you a surgery
Good exercise protocol and functional training can help you a lot if you
Next Steps
The final call is yours after taking into consideration your physical activity level and weight
Health Tips
Use a brace to support to knee at least for 6weeks from the date of injury while walking and sleeping
Apply ice packs to release pain and reduce swelling if any
If you decide not to get operated get a good rehabilitation
Rehabilitation is must whether or not you get operated