Hello and hope you are doing well.
You have not mentioned what the spinal infection was and the therapy received. Levothyroxine is unlikely to cause the foot and toe cramps. The ongoing pain in the leg could indicate that there is progressive damage to the nerves. NCS, nerve conduction studies may show the effects on the nerve. The compression on the nerves needs to be relieved. Therapy for spinal disorders can be conservative (non operative) and surgical (operative) management. Non operative therapies are ultrasound application, spinal traction, transcutaneous electric nerve stimulation and spinal injections. I would advise you to discuss various options with your doctor and initiate the right therapy for relief from pain.
Hope this helped and do keep us posted.