I guess that is an excerpt from your MRI/CT report. May I ask why did you get C5-6 disc replacement in the first place? I am not sure whether this had already been present before your C5-6 disc replacement surgery or it is a response/side effect associated with your surgery.
However, your symptoms of muscle weakness, tingling and spasm can be caused by the exit foraminal narrowing, because the narrowing could compress the spinal nerves! I think you may make an appointment with your surgeon and discuss whether the MRI/CT findings require any further treatment.