Meniscus is within the joint. Meniscal injuries may sometimes be associated with capsular tears which may mimic a never related pain in the back of the knee. What you might be experiencing is probably the capsular injury in the back of the knee joint. Nerve pains are usually radiating or is along a group of muscles. It's highly unlikely that you sustained a nerve injury along with Meniscal injury. If there is indeed a nerve related problem, it must be an incidental finding and is definitely not related to the meniscal injury
Next Steps
MRI of the Knee Joint
Apply Ice and give rest to the knee
take a pain killer in case of severe pain
Health Tips
Do not Massage over the pain area or swelling area