Dear Jesse, The symptom of numbness as mentioned in your post can be attributed to nerve compression which might have occurred during the post surgery period period. The roots of the nerve which supply the foot arise from lower back. Any post operative compression in the area will cause such symptoms. Though symptomatic relief may be obtained with nervigenic agents like Vit B6, Vit B12, Folic acid, etc. the underlying cause needs to be treated. So, kindly consult a Neurologist & get a proper clinical examination done, including nerve conduction studies. The ringing sensation in ear can be due to many reasons like infection, eustachian tube dysfunction, noise trauma, ototoxic drugs, systemic conditions like hypertension, anemia, etc. Kindly visit an ENT specialist for proper evaluation & management. Wishing you a good health. Take care.