How Long Does a Broken Ankle Take to Mend? The Borderline Cases and How They Get Called

A broken ankle unites on X-ray in six to twelve weeks. Symptoms outlast the bone. NHS fracture-clinic leaflets put pain, stiffness and swelling at six to twelve months, and swelling alone at six to nine months after surgery. A stable fracture is normally protected in a boot or cast for about six weeks, weight-bearing as pain allows. A fracture held with a plate and screws no longer means six weeks off the leg. The WAX trial, published in The Lancet in June 2024 across 23 NHS hospitals and 561 patients, found that walking from two weeks after surgery gave slightly better ankle function at four months (mean Olerud-Molander score 65.9 against 61.2) with no significant rise in complications. Age, diabetes, smoking and how much joint surface was involved move every one of those numbers.

Protecting the ankle between appointments

Swelling peaks in the two weeks following injury or surgery, and most of what helps then is mechanical. The NHS fracture-clinic leaflets I compared (Royal United Hospitals Bath, Chelsea and Westminster, East Kent) converge on one list.

1. Keep the foot above heart level when sitting or lying. Some trusts write "above hip level"; the heart is the line that moves fluid.
2. Wear a walking boot only for walking. Take it off to sleep and shower, moving the toes and foot while it is off. In a cast, move the toes only.
3. Never post anything down a cast to scratch it, never trim one that rubs, and skip cold packs over plaster.
4. Move the hip and knee on the injured side daily.
5. Keep the follow-up appointment.

Point five is there because I got it wrong. In my advocacy years I read the two-week slot as ordinary scheduling and helped a caller push hers back to fit a shift rota. It slipped to five weeks. BOAST 12, the British Orthopaedic Association standard, says that where stability is uncertain the patient should be reviewed within two weeks with repeat radiographs, weight-bearing if possible, to catch a fracture that has moved. Hers had, and the next conversation was about an operation rather than a boot.

Fracture or sprain, when both are swollen and neither will take weight

Fewer than 15% of people arriving at an emergency department with an acute ankle injury have a clinically significant fracture. Bruising, swelling and refusing to stand do not separate the groups. The Ottawa ankle rules do, working on where the bone is tender rather than how bad the ankle looks: an X-ray is indicated for bone tenderness at the posterior edge or tip of either malleolus, over the navicular, or at the base of the fifth metatarsal, or if the person could not take four steps at the time and cannot take four now.

Bachmann and colleagues pooled 32 studies and 15,581 patients in the BMJ in 2003 and reported 97.6% sensitivity with median specificity of 31.5%. A 2022 meta-analysis in BMC Musculoskeletal Disorders, covering 8,560 patients across 13 countries, put sensitivity considerably lower at 91%. I would rather give you both than the flattering one. A negative result makes a fracture unlikely enough to go home without a film, while a positive one usually means the X-ray is justified rather than that something is broken. Walking on it proves less than it feels: plenty of stable fractures allow four steps on the day.

Stable or unstable: the millimetres that decide the plan

Once a fracture is on the film, one question governs everything downstream: does the talus still sit square under the tibia when loaded? For an isolated Weber B fracture, where the fibula breaks at joint level, the measure is the medial clear space between malleolus and talus, threshold 5.0 mm.

The stress test used changes the answer to a startling degree. The same injuries are called unstable on up to 3% of weight-bearing films and on 48% of gravity stress films. An arthroscopic study in Foot and Ankle Surgery looked directly at the deep deltoid ligament: for a rupture, the weight-bearing radiograph reached 83.3% sensitivity and 100% specificity, the gravity stress test 100% and 0%. A gravity view calls nearly everything unstable; a weight-bearing film that stays reduced is telling the truth.

| Injury | How the call gets made | What holds it | Weight-bearing | Time to mostly normal | |---|---|---|---|---| | Lateral ligament sprain | Ottawa rules negative, no film | Brace or tape, early movement | As pain allows, day one | 1-3 weeks mild, 4-8 moderate | | Stable fracture | Clear space under 5 mm on a weight-bearing film | Boot or cast, about 6 weeks | As tolerated | 6-12 weeks to unite | | Unstable fracture | Shift under load, two malleoli, or syndesmosis | Plate and screws | From 2 weeks post-surgery (WAX) | 6-12 weeks to unite, 4-8 months to sport |

I cannot read your radiograph. I have never been able to tell from a described symptom whether a medial clear space is 4 mm or 6 mm, and that difference is a boot or an operation. What I can do is the work my beat trained me for. The report is a record about you, you can request it, and the line to look for says which view the clear space was measured on.

How long you stay off it: what changed in 2024

Radiographic union is scored as mature callus bridging three of four cortices on two views, and most ankle fractures cross that line between six and twelve weeks. Plain films run behind the biology, which is why a six-week X-ray can look unconvincing beside an ankle that already feels better.

Six weeks of non-weight-bearing was the default for decades and was never properly tested in the people who actually break ankles; earlier trials excluded open fractures, syndesmotic injuries, poor bone quality and anyone over 65. WAX did not. At four months the early group scored 65.9 on the Olerud-Molander scale against 61.2, complications ran at 16% early against 14% delayed (adjusted odds ratio 1.18, 95% CI 0.80 to 1.75), and costs came out at £725 against £785.

I used to hand people that six-week figure as the safe thing to ask for. Families rang the advocacy office worried they were being rushed back onto the leg, and I told them the conservative protocol existed and they could raise it. I stopped in the second half of 2024, once WAX published. The question I ask now is duller: which weight-bearing instruction is written on your discharge letter, and what reason is recorded next to it? BOAST 12 says most patients should bear weight as tolerated unless there is a specific concern about the fixation, peripheral neuropathy, or the soft tissues. "It is what we do here" is not one of those.

Stiff, swollen and still not right at four months

In a prospective cohort of 142 patients aged 18 to 65 whose fractures were fixed, 72% still reported stiffness at one year and only 52% had returned to their pre-fracture activity level. The same study measured a mean side-to-side difference of 3.22 cm on the weight-bearing lunge test at twelve months, a persistent loss of dorsiflexion.

Reference values put dorsiflexion at roughly 20 degrees with the knee bent and 10 with it straight, plantarflexion at 40 to 50, and walking needs about 15 degrees of dorsiflexion. Your clinic measures the injured side against the other one, and that comparison is the number to ask for.

Swelling is worst in the first fortnight, then lingers at the end of long days for six to nine months after surgery. A newly painful or swollen calf is another matter, though symptomatic clots are uncommon. A nationwide analysis in Injury found deep vein thrombosis in 0.4% and pulmonary embolism in 0.3% after foot and ankle fractures, with cast treatment carrying roughly twice the DVT risk of surgery; in matched below-knee cohorts, hindfoot and ankle procedures showed 1.4% venous thromboembolism without chemical prophylaxis and 0.4% with it. Search it yourself and you will hit 5% to 40%, figures from studies that scan everybody and mostly find silent calf clots. I read that same arithmetic for years in maternity notes; it works identically here.

Which symptoms need assessing the same day

Any of these needs looking at today, not at the next appointment.

• Numbness, pins and needles, or a foot that has turned pale, dusky or cold.
• Pain escalating instead of settling, especially deep unrelenting pain under a cast or a burning pressure point.
• New calf pain, swelling or tenderness, and above all breathlessness or chest pain.
• Spreading redness from a surgical wound, discharge, a wound that opens, or fever.
• A cast or boot suddenly loose, or a sudden change in the ankle: a pop, a shift, the loss of a movement you had yesterday.

Diabetes and smoking belong here too. In a propensity-matched analysis, nicotine users having bimalleolar fractures fixed showed higher wound disruption and infection at 90 days and higher nonunion and revision rates at two years. Infection in operatively treated diabetic ankle fractures has been reported as high as 30%.

Driving, work and sport: the months nobody schedules

Egol and colleagues put 31 patients with fixed right ankle fractures into a braking simulator, publishing in the Journal of Bone and Joint Surgery in 2003. Total braking time was still prolonged at six weeks, worth about 23 feet of extra stopping distance at 60 mph, and normalised at nine weeks.

The strongest case against me is a good one. Ho and colleagues, in Archives of Orthopaedic and Trauma Surgery in 2018, went past the simulator: they ran patients with surgically treated right ankle fractures through a full on-road assessment with a driving instructor, and those patients passed a standard driving test at six weeks, some before weight-bearing had started. A road test measures the thing we care about; total braking time is only a proxy, and I grant it. What neither study can tell you is what your insurer will accept after a collision, so get the clearance written down. In the UK the obligation is to be in full control of the vehicle, not to have reached a particular week.

Work and sport diverge. In the 142-patient cohort, 97% of those in work were back within a year, with delays concentrated among older workers, construction trades and falls from height. A 2025 systematic review of 17 studies and 1,422 patients found an 87.1% return-to-sport rate at an average of 134.5 days. A retrospective series of 93 patients split it by pattern: unimalleolar 100% by a median of four months, bimalleolar 80.8% by six months, trimalleolar 65.2% by eight months. Only 40.9% were back at their pre-injury level a year on.

Will the joint be the same afterwards?

Ankle arthritis is an injury disease: 70% to 80% of ankle osteoarthritis is post-traumatic, the reverse of the pattern at hip and knee. A 2022 systematic review in EFORT Open Reviews pooled the radiographic figures: osteoarthritis, defined as joint space narrowing, appeared in 25% of ankle fractures (95% CI 18 to 32), rising to 34% (95% CI 23 to 45) with the posterior malleolus involved. Trauma severity was the strongest prognostic factor, and the review could not say when arthritis starts to hurt.

Radiographic arthritis and painful arthritis are not the same population, and the gap is where most people live. Risk clusters around age 60 and over, BMI of 28 or more, heavy physical work, a posterior malleolar fragment covering more than a quarter of the joint surface, and any step-off left after fixation. That last one is worth raising at your post-operative review, because it is the only item on the list that was somebody's decision.

Frequently asked questions

How long should you stay off a broken ankle?

It depends on the fracture and what is holding it. Stable fractures are usually weight-bearing as pain allows from the start, in a boot for around six weeks. After surgery the WAX trial supports walking from two weeks. Follow the instruction written on your discharge letter.

Will my ankle ever be the same after a break?

Often close, rarely identical. A one-year study of 142 surgically treated patients found 72% still reported stiffness and only 52% had returned to their pre-fracture activity level. Radiographic arthritis appears in about 25% over time. Most people walk, work and exercise normally with some loss of end-range movement.

How long does a broken ankle take to heal with surgery?

The bone unites on X-ray in roughly six to twelve weeks, the same window as a fracture treated without surgery; metalwork holds the position rather than speeding healing. Function lags. Average return to sport across 1,422 patients was 134.5 days, and swelling can persist six to nine months.

When can you start walking after a broken ankle?

With a stable fracture, usually straight away, weight-bearing as tolerated in a boot or cast under BOAST 12. After fixation of an unstable fracture, the WAX trial found walking from two weeks post-surgery gave better function at four months than waiting six, with no significant rise in complications.

How is a stable ankle fracture different from an unstable one?

Stability describes whether the talus stays centred under the tibia when the joint takes load. A stable fracture keeps the medial clear space under about 5 mm on a weight-bearing radiograph and is treated in a boot. An unstable one shifts, or breaks two sides, and is fixed surgically.

Which symptoms after a fracture need urgent assessment?

Numbness, a cold or pale foot, escalating pain under a cast, new calf pain or swelling, breathlessness or chest pain, spreading redness or discharge from a wound, fever, or the sudden loss of a movement you had yesterday. Any of these means same-day assessment.