Chronic pain in ball of foot after bunion surgery (nerve pain?)

by Lars
(CA)

I am 45 years old, 6'2" and 166 lbs. I had bunion surgery on both feet almost 6 months ago (bunionectomy with fixation). After about 2 weeks, I was able to start walking some and after 3 weeks, the pins were removed. I gradually worked up from a few minutes to 30 minutes; after 8 weeks I was taking daily walks of about 30-45 minutes. There was extra pressure under the fifth metatarsal (especially on the left foot), but was told that it will go away and nothing worry about. It has not gone away.

After about 10 weeks, there was one day when I took two walks of about 45 minutes in the same day; I felt barely any discomfort except for at the end of the last walk when my feet started getting sore and a bit painful. The following days were fine, but about a week after that day I suddenly regressed and my feet became quite painful and I had a hard time walking at all. I stayed off my feet for several days and it calmed down some.

I am not sure if the extra walking that one day had anything to do with it, but I still have not recovered from that regression. I am now over 5 months past the surgery and still cannot walk (or even stand) without discomfort / pain. If I walk more than about 5-10 minutes, it tends to flare up again and hurt more for several days.

The pain is centered around the fifth metatarsal on both feet (the left is the worst), but the whole ball of the foot seems tender and sensitive (with fleeting pain in other areas, such as the first metatarsal). The pain is of an aching, burning kind (slightly prickly - hard to describe). However, some weeks ago, there was a couple of periods of a few hours when the feet felt almost normal – virtually no discomfort or extra pressure on the fifth metatarsals.

The podiatrist who did the surgery does not know why it still hurts and said it can take up to a year to fully heal.

Since there is absolutely no sign of improvement and this condition is keeping from doing anything that requires more than 5-10 minutes of being on my feet, I am getting desperate and do not want to just sit and wait for it to hopefully eventually go away.

I recently saw a highly regarded orthopedic surgeon for a second opinion. He noted that the fifth metatarsal on the left foot was not correctly set (I do not remember the word he used): the pinkie toe is pointing a bit upwards instead of being flat as the other toes, which make the area where the bone was cut a bit lower than it should; this explains the extra pressure under the left foot fifth metatarsal. I have attached a picture to illustrate.

Question #1: is it common that the surgeon accidentally fixates the metatarsal not quite straight like this?

So there is a mechanical issue with the left fifth metatarsal, but that does not explain why other areas of the foot, as well as the right foot also hurt. The pain in the other areas (not around the fifth metatarsal) is more diffuse (=the ache is usually less intense, but still burning and slightly prickly).

I have tried two pairs of orthotics, but they provide only little relief (even with metatarsal pads); however, perhaps once the nerve issue (or whatever it is that is causing the general diffuse ball of the foot pain) has been resolved, the orthotics will work fine for me.

On the surgeon's suggestions, I have done blood tests for arthritis, lupus, etc. They were all negative.

Question #2: as a last resort if nothing else has worked, what is your opinion on a revision surgery to straighten out the left foot fifth metatarsal? 70% of the pain is in this area.

I did physical therapy for a few weeks, but that only provided temporary relief after each visit (perhaps the ultrasound or massage). Rolling a ball under my foot and calf stretches daily did not seem to help.

Question #3: Do you think Voltaren gel for a couple of weeks could help? The amount of pressure under the fifth metatarsals varies, so perhaps inflammation is causing variation in swelling of the metatarsophalangeal joint?

Your opinion and recommendations would be greatly appreciated.

RESPONSE

Hi Lars,

Question #1: is it common that the surgeon accidentally fixates the metatarsal not quite straight like this?

I am assuming your original pain was on the outside of the fifth metatarsal as opposed to the under side of the metatarsal head. This is usually the problem.

That being the case your surgeon probably performed an osteotomy, cutting of bone, to move the metatarsal head closer to the fourth metatarsal head. It appears that not only did he move it over, but he also slightly plantarflexed it (moved it downward) when he fixated it. That is why you have the added pressure underneath the head

In foot surgery, when a metatarsal head is plantarflexed, it will force the toe upward. This is why your fifth toe is not touching the ground.

In defense of your surgeon, this type of surgery is not an exact surgery and problems like this can and do happen. I have no hard statistics on how often it happens but I would venture to guess not terribly often, because in most cases the patient does not have any issues even if the alignment is "off" a little bit.

What I do not like about your whole narrative is the fact that you did so much walking early on after the surgery. You mention K wires were removed and I will assume they were the only means of fixation for the osteotomy. If I am wrong let me know.

Call me conservative, but when I do these types of procedures, and use k-wires, I also put my patients in walking boots to further stabilize the osteotomy site and have them rest their foot, not go out on long walks.

That is also the reason I only do one foot at a time when doing an osteotomy, to give the surgical site all the protection it needs to properly heal.

What I am saying here is that all the walking you did with minimal protection may have dislodged the osteotomy slighty and may be part of the problem.

So, unless I do not totally understand the time line here, I am concerned about the instructions you were given after surgery.

I think it is worth mentioning that one possibility for your pain might be from damage to the nerves on the bottom of your foot which may have occurred during surgery. Either excessive dissection or using too large a bone saw blade might have actually done damage to the nerves of the branches of the lateral plantar nerve that pass through that area. Difficult to know from this side of the internet.

Question #2: as a last resort if nothing else has worked, what is your opinion on a revision surgery to straighten out the left foot fifth metatarsal? 70% of the pain is in this area.

First of all, it has only been six months since the surgery and your surgeon is correct that it can take upwards of a year for bone to remodel itself, although I do not think your problem is in the bone, but you never know. You would not consider revision surgery until at least one year has passed.

Making the assumption that the osteotomy site has completely healed, both on x-ray and clinically by pressing on the bone itself to see if there is any pain, my suggestion would be to consider a cortisone injection underneath the head of the bone, or even consider a round of oral prednisone.

I suggest this because over the years when I have had post op patients with "soft tissue" issues of pain, I have found that an injection or a round of oral prednisone can be very effective in alleviating the pain.

As far as revisional surgery goes, you will have to use my "risk vs. reward" formula. What any honest surgeon will tell you is that every time you have surgery on the same spot, particularly a small area such as the fifth metatarsal head, additional surgery could make matters worse usually because of excessive scarring that occurs.

If you do eventually have a second surgery you better make sure the surgeon knows exactly what the problem is, because in these instances the risk vs. reward ratio is working against you.

Question #3: Do you think Voltaren gel for a couple of weeks could help? The amount of pressure under the fifth metatarsals varies, so perhaps inflammation is causing variation in swelling of the metatarsophalangeal joint?

Voltaren is harmless enough to try and probably useless in the long run. I have tried it a number of times and have been underwhelmed by its effect, but there is no downside risk to using it.

Based on what you have written, I do not think this is a joint problem, but again, I do not have the luxury of actually examining you. Joint pain generally does not cause burning. Personally I think an injection or oral prednisone would be a better option.

Good luck.

Marc Mitnick DPM
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