I have periodic intense pain on the top of my foot.Feels like a knife going through my foot.This can occur several times a day or only a few times.It doesn't really matter if I am wearing orthotics or bare feet. Podiatrist said it was a strained tendon. X-ray shows no fracture. Pain comes and goes. I could be resting, walking, action doesn't seem to matter. Not affected by ice, NSAIDs,. What is causing this?
Although I cannot say for sure what is going on with your foot, I will tell you that tendonitis generally hurts all the time. Since it is an inflammation of the tendons that bring your toes upwards it would tend to hurt every time you walk, in varying degrees. Additionally, there will be mild swelling over the area where the tendon is inflamed. If you take your hand and manually bend your toes downward that will tend to make the tendonitis, if it is that, painful. Other things that can cause pain on the top of the foot would include a midtarsal fault (you can read about it, to the left of this column). That is a problem where the top of the arch collapses too much causing a "jamming" of two of the bones on top of the foot and that jamming will cause pain. Orthotics tend to help this condition simply because they prevent the foot from collapsing when you ambulate. You do not mention why you have orthotics but I would be curious to know if it has any thing to do with a midtarsal fault. Next thing to consider might be a strained ligament. A ligament is a leather like material that attaches two bones together so that they stay in place. Sprained ligaments are very common in the ankle, but they do occur in multiple places on the foot and they could pain that can be very intense while at other times not so much. The last thing that comes to mind is a stress fracture. The problem with this is that usually fractures hurt all the time, more intense than other times. Keep in mind that not all fractures will initially show up on an x-ray. So...what should you do? The first thing is that you need an accurate diagnosis. If the pain is as intense as you state you need to rule out a neurological or vascular problem. I do not know how old you are so I do not know the potential for these being the source of your foot pain. I will also assume your podiatrist has also checked your circulation and your neurological status. The next thing you should consider doing would be to have an MRI of the foot, the purpose of which would be to get a better look at what might be the source of your pain. An MRI can be very good at finding small fractures which would not be picked up on x-ray. Additionally, an MRI would tell you if there is any soft tissue damage such as ligament or tendon damage. This is all about your degree of comfort. If the pain is as intense as you state and you are finding it is occurring more frequently, then you should move forward in finding an answer to your problem.