Hello dear, Though symptomatic relief from pain can be obtained with application of Naproxen ointment, the underlying cause needs to be treated to avoid recurrence. Investigation like X ray of the knee joint will be helpful to rule out any pathological cause for the symptoms. Leg cramps at night can also be due to peripheral neuropathy or electrolyte imbalance in the body. You need to take nervigenic agents (like Vit B6, B12, Folic acid). Multivitamin & mineral supplements containing iron, calcium need to be added to your diet. Wishing you a good health. Take care.