My husband is 30 years old and had spinal fusion back surgery 4 weeks ago. He was injured at work, we went for the 1st neurosurgeon appoitnment and he ordered emergency surgery. He said he only does emergency back surgery 2-3 times per year. But, my husband had a crushed nerve that was causing paralysis in the left leg, he wen to doctor using cane and had been in unbelievable pain for about a month. It has been UNREAL how much better he is already! He will begin physical therapy this week, but immediatly he had the use of his left leg again, he was taking so many pain pills before surgery, now he hasnt even had one in over a week!! But, I have a question about this popping in his back, it happens several times a day. He is following the strict orders from the doctor, wearing restrictive brace all day, bone stimulator, muscle stimulator, etc. But, does anyone know what exactly the popping sound is?