About one in four bunion corrections comes back. That number surprises most people, and it is not because the surgery failed in the operating room — it is usually because the deformity was measured in two dimensions and corrected in two dimensions, when the problem was always in three.
This article is about what the X-ray actually decides before anyone picks up a scalpel, and why two patients with what looks like the same bunion can need entirely different operations.
The bump is not the deformity
The lump on the side of the foot is the part everybody points at, and it is the least interesting part of the problem.
A bunion — hallux valgus — is not an overgrowth of bone. It is a drift. The first metatarsal, the long bone behind the big toe, migrates away from the second metatarsal, toward the inside of the foot. The big toe leans the opposite way to compensate. The prominence you can see is simply the head of that first metatarsal, now sitting where there used to be nothing.
Shave off the bump and leave the drift, and the drift wins. That is the oldest lesson in this operation, and it is why nobody serious performs a simple bumpectomy any more.
Two angles decide which operation you get
Bunion surgery is not one procedure. It is a family of them, and the choice between them is made on a weight-bearing X-ray using two measurements.
The hallux valgus angle (HVA) is the angle between the big toe and the first metatarsal — how far the toe itself has leaned over. The intermetatarsal angle (IMA) is the angle between the first and second metatarsals — how far the bone behind the toe has drifted.
Published classification puts the thresholds roughly here:
| Severity | Hallux valgus angle | Intermetatarsal angle |
|---|---|---|
| Normal | under 15° | under 9° |
| Mild | under 20° | 9° to 11° |
| Moderate | 20° to 40° | 11° to 16° |
| Severe | over 40° | over 16° |
Those bands are not academic. They map onto procedures. Mild deformity is generally addressed with a distal osteotomy — a cut near the head of the metatarsal, which can shift the bone sideways a limited distance. Moderate deformity usually calls for a proximal osteotomy, a cut further back where a small angular change at the base produces a much larger movement at the far end. Severe deformity points toward a proximal correction or a first tarsometatarsal fusion, which stabilises the joint at the very base of the metatarsal where the drift often originates.
The logic is leverage. A cut near the toe end has a short lever and a hard ceiling on how much it can correct. Ask it to do a moderate or severe deformity’s worth of work and it will run out of bone before it runs out of deformity.
A worked example
Take a patient whose weight-bearing films show an HVA of 28° and an IMA of 14°.
Both land squarely in the moderate band — the toe is well past the 20° mark, and the metatarsal drift is past 11°. On the classification above, that is a proximal correction. If it were done with a distal osteotomy instead, the surgeon would be asking a procedure built for a 9° to 11° gap to close a 14° one. It might close on the table. The question is whether it stays closed at year five, and the honest answer is that it often does not.
Now change one number. Same 28° toe, but an IMA of 10°. That is a mild drift with a toe that has leaned further than the bone has, and a distal procedure with a soft tissue release is a reasonable plan. Same-looking foot in a shoe. Different operation.
The sesamoids are the part nobody mentions
Underneath the head of the first metatarsal sit two small bones, the sesamoids, embedded in the tendon that flexes the big toe. They run in a groove on the underside of the metatarsal head, and they are the reason the big toe can push off with real force.
As a bunion develops, the metatarsal does not only drift sideways — it rotates. The sesamoids stay roughly where they are, tethered by their tendons, so the metatarsal head effectively rolls off them. On an X-ray this shows up as the sesamoids appearing to sit further and further to the outside of the metatarsal, and it is graded on a scale from 1, meaning normal position, to 7, meaning complete dislocation.
This is the measurement that predicts whether a correction lasts. In a meta-analysis of 23 studies covering 2,914 patients, the pooled prevalence of recurrence after hallux valgus surgery was 24.86%, and the two strongest correlates of recurrence were the postoperative hallux valgus angle and postoperative sesamoid position — a sesamoid grade above 4 being the point at which risk climbed sharply.
Read that carefully, because it is the whole argument. Recurrence was not predicted by the patient’s age, or shoes, or how bad it looked before. It was predicted by how completely the correction restored normal anatomy, including the rotational component. A correction that closes the angles on the post-op film but leaves the sesamoids uncovered has not put the foot back together. It has made it look right in one plane.
Dr. Albert Samandarov walks through how a bunion is measured before surgery, and why the rotational component is the part that decides whether a correction lasts:
Where this goes wrong
These are the failures worth understanding before consenting to anything.
The bunion comes back
Roughly one in four, on the pooled figure above. In the long-term literature the numbers move around a great deal depending on where you set the threshold — one long-term review of shaft osteotomies at eight to fourteen years’ follow-up found 40% of feet had an HVA above 15°, 20% above 20°, and only 2% above 25°. In other words, a lot of feet drift back a little, and a small minority drift back enough to matter clinically. Whether your surgery is called a recurrence depends partly on where the line is drawn.
What matters to a patient is whether the toe hurts and whether it fits a shoe. Ask about that, not about the angle.
The rotation was never addressed
This is the mechanism behind most of the first failure. The sideways gap gets closed, the films look tidy at six weeks, and the metatarsal is still rotated. The sesamoids never come back under the bone, the tendon that flexes the toe keeps pulling along a line that drags the toe outward, and the deformity has a reason to redevelop from the day the cast comes off.
The pain relocates to the second toe
Most bunion procedures shorten the first metatarsal slightly, or lift it a little. Both reduce how much load the big toe carries, and that load has to go somewhere — usually straight to the second metatarsal head, producing pain under the ball of the foot that was not there before. It is called transfer metatarsalgia.
There is a measurement that flags the risk in advance. In one series of 126 patients, 34 of them — 27% — developed transfer metatarsalgia, and the preoperative relative length of the second metatarsal separated the two groups clearly. A cutoff of about 2 mm of relative excess length identified those at risk with 79% sensitivity and 78% specificity, and each additional millimetre carried roughly a fivefold increase in risk.
If your second toe is already noticeably longer than your big toe, that is worth raising at the consultation. It does not rule out surgery. It changes how much shortening is acceptable, and it is a reason some patients have a second-toe procedure or a hammertoe correction planned at the same sitting rather than a year later.
The joint ends up stiff
The big toe joint needs roughly 60° of upward motion to walk normally. Scarring, an overtightened repair, or a fusion performed higher up the foot can all leave less than that. The result is a toe that no longer bends at push-off, so the foot rolls off the outside instead — which is comfortable for nobody and hard on the outer forefoot over years.
Stiffness is far easier to prevent than to fix. Early controlled motion, once the surgeon allows it, is not optional physiotherapy — it is part of the operation.
The operation was done for the bump
A bunion that does not hurt, does not stop you wearing reasonable shoes and is not progressing does not need an operation. Correction performed for appearance alone has the worst satisfaction figures in the entire procedure, because the patient starts from no pain, and the only available directions are sideways and down.
A widening bunion in a teenager, or one that has visibly moved in two years, is a different conversation. Progression is an argument. Appearance on its own is not.
Shoes went back on by the calendar
Bone heals on its own schedule, not on a diary. Going back into a normal shoe before the osteotomy has consolidated puts a bending force straight across the cut — a way of losing correction that has nothing to do with how good the surgery was. Cutting protected weight-bearing short because the foot feels fine is one of the few post-operative decisions a patient makes entirely alone.
What a proper pre-operative assessment includes
If you are being worked up for a correction, these should all have happened:
- Weight-bearing X-rays. Not lying down. A bunion partially reduces when the foot is unloaded, so non-weight-bearing films understate the deformity, sometimes substantially.
- Both angles measured and told to you. The HVA and the IMA, in degrees, along with which severity band they put you in.
- Sesamoid position assessed. If the rotational component has not been discussed, ask.
- Relative metatarsal lengths looked at. Specifically whether the second is long.
- The first tarsometatarsal joint checked for motion. Excess motion at the base of the metatarsal is a reason to stabilise there rather than further forward.
- A named procedure, with a reason. Not “we’ll see when we get in there.” The films should already have decided most of it.
Conservative care sits alongside all of this and is worth exhausting first in most adults. It will not straighten the toe — nothing non-surgical does — but wide shoes, offloading pads and custom orthotics can control the symptoms well enough that surgery stops being necessary, which is a perfectly good outcome.
Common questions
Will a splint or a toe spacer straighten my bunion?
No. They can ease symptoms by holding the toe in a more comfortable position while you wear them, and there is no harm in trying. They do not move bone, and the deformity returns the moment they come off.
How long before I can drive and go back to work?
It depends heavily on the procedure and which foot. A desk job is often manageable within two to three weeks with the foot elevated much of the day; a job on your feet all day is usually six to twelve weeks. Driving needs the right foot to be reliable for an emergency stop, which for a right-sided correction is typically several weeks beyond the point at which the foot feels fine. Your surgeon’s figure for your specific operation is the one to use.
Can both feet be done at once?
Sometimes, and it is a genuine trade-off rather than a right answer. One recovery instead of two is a real advantage. Against that, you lose the good foot to stand on, which makes the first fortnight considerably harder and matters more if you live alone or have stairs.
Does a bunion come back because of my shoes?
Shoes are a contributor to developing one, not the main reason a corrected one recurs. The evidence points at how completely the deformity was corrected, particularly the rotational component. That said, going back into a narrow toe box after correction is not doing the repair any favours.
I had this done years ago and it has come back. Can anything be done?
Usually yes, though revision is a bigger operation than the original and the assessment matters even more. The key question is why it recurred — an under-corrected drift, an unaddressed rotation, or instability at the base of the metatarsal each point to a different revision. A revision planned without answering that question tends to reproduce the original result.
Where to take this next
If you have films already, bring them. If you do not, ask for weight-bearing views and ask what your two angles are. A patient who knows their HVA and IMA can ask the one question that matters most: how does this procedure address the rotation, not just the angle?
You can read how bunion surgery at the Astoria and Floral Park offices is planned and what the recovery involves, including which procedures are performed for which severity.
Ideal Podiatrist Foot-Ankle DPM Bunion Surgery & Foot Fungus Laser
Astoria, Queens
31-16 30th Avenue, Suite 203
Astoria, NY 11102
718-626-3338
To have a bunion assessed, call 718-626-3338 to book with Dr. Albert.
This article is general information and not a diagnosis or medical advice. Figures quoted are population averages from published research and do not predict any individual result. For advice about your own feet, see a podiatrist.
