Deep Trouble
Some complications hurt. Some hide.
After ankle surgery or a serious injury, most of the attention goes to bone healing, pain and getting around. But there’s another complication worth knowing about: blood clots.
A clot that develops in one of the deep veins of the leg is called a deep vein thrombosis (DVT). If part of that clot breaks loose and travels to the lungs, it can cause a pulmonary embolism (PE), which can be life-threatening.
You should know the warning signs and what you can do to reduce your risk.
FROM THE TRENCHES
My fracture friends have had very different experiences with DVTs. One was impossible to ignore. The other was dangerously easy to dismiss.
One woman knew something was wrong because the excruciating pain in her calf demanded attention. After doing everything she had been told to do — getting up, moving around, trying to prevent a clot — an ultrasound confirmed a DVT.
Another patient’s experience was frightening for a completely different reason: her DVT barely announced itself.
She had pain in the back of her calf and what felt like referred pain in the back of her thigh. That was it. No swelling. No redness. Her doctor and physical therapist thought she was having muscle cramps.
Then one night, while comforting her daughter after a bad dream, something happened that she later learned was a small pulmonary embolism. She still didn’t call an ambulance because she didn’t want to wake her family or bother everyone in the middle of the night.
The next day, an ultrasound found a clot in her calf. A CT scan found another in her lung.
Looking back, she reflected that she should have listened to the people who had urged her to get checked, and pushed for an ultrasound no matter how few her symptoms were.
Deep Vein Thrombosis (DVT)
A DVT forms in a deep vein, usually in the leg.
Common symptoms include swelling in one leg, particularly in the calf; pain or tenderness that isn’t readily explained by the injury or incision; warmth in the affected area; and red or discolored skin.
But not every DVT causes obvious symptoms. And swelling and pain are already common after ankle surgery, which can make a clot difficult to distinguish from normal recovery. New, worsening or unexplained symptoms deserve attention.
Pulmonary Embolism (PE)
A pulmonary embolism can occur when part of a blood clot breaks loose, travels through the bloodstream and becomes lodged in an artery in the lungs.
Warning signs can include sudden shortness of breath; chest pain, particularly pain that worsens with a deep breath; rapid heartbeat; lightheadedness or fainting; and coughing up blood.
A pulmonary embolism is a medical emergency. If you develop symptoms suggesting a PE, call 911 immediately. Don't attempt to drive yourself to the hospital.
Why Ankle Surgery and Injury Increase the Risk
Reduced mobility:
Walking normally activates the calf muscles, which help move blood back toward the heart. Non-weight-bearing and limited activity take away much of that pumping action.
Immobilization:
Casts, splints and boots restrict normal ankle and calf movement.
Surgery:
Surgery temporarily increases the body’s tendency to form clots as part of its normal response to tissue injury.
Trauma and inflammation:
The original injury itself may contribute to clotting risk.
Individual risk factors:
Previous blood clots, increasing age and certain medical conditions can raise risk further.
MY TAKE ON IT
After my ankle hardware removal surgery, I was non-weightbearing for two weeks. After I’d been walking—and exercising pretty aggressively—for another two weeks, my calf became very sore. My leg was hot and swollen.
I’d been active for a couple of weeks. I was taking low-dose aspirin. I wasn’t obese. I didn’t smoke. Surely, I didn’t have a DVT. But what if I did?
I spiraled on the merry-go-round of thoughts that most of us have. I was probably okay. But…
The following day, my calf was still sore. I burned up the internet searching for symptoms.
Then I figured, if I went to the ER, the worst-case scenario was that I’d be embarrassed for overreacting. I mean, if I didn’t have a DVT. I messaged my doctor and she advised I get in for an ultrasound right away.
Turns out, getting the ultrasound took a few hours out of my day, cost a little bit of money, and I ended up fine. And a lot less worried.
Even knowing I did the right thing, I’m still a little embarrassed about it. But at least I’m not dead.
Helping Prevent Blood Clots
Your surgeon should decide what level of prevention is appropriate for you. Not every ankle patient needs the same thing.
Medication
Depending on your individual risk and the procedure, your surgeon may recommend aspirin or a prescription anticoagulant. Don’t start aspirin or another blood thinner on your own. These medications can increase bleeding and may not be appropriate for everyone.
Movement
When your surgeon allows it, movement helps keep blood circulating. Even while you’re non-weight-bearing, you may be allowed to move your toes, bend your knee and move the leg.
Ankle pumps can also help activate the calf muscles, with the same caveat—if your surgeon has cleared you for ankle movement.
Compression
Compression stockings or other compression devices may be recommended for some patients to help maintain blood flow in the legs. Ask before using them. Compression may not be appropriate over an incision, cast, splint or certain injuries.
Hydration
Dehydration may contribute to clotting risk, so drink regularly during recovery unless you've been told to restrict fluids for another medical reason. Hydration is no substitute for other clot-prevention measures.
How Common Is DVT After Foot and Ankle Surgery?
The numbers vary considerably depending on the type of injury or surgery, the patient’s individual risk factors and — importantly — whether researchers count only symptomatic blood clots or routinely screen patients who have no symptoms.
One 2024 study of 278 patients who underwent foot and ankle surgery and were screened for DVT with postoperative duplex ultrasound found DVT in 14.7% of patients. Most were isolated distal clots below the knee, and 92.7% of the patients with DVT had no symptoms. Acute trauma, previous DVT and older age were significant risk factors.[i]
That doesn’t mean 14.7% of everyone who has ankle surgery will develop a clinically significant blood clot. It does show something important: DVT can occur without announcing itself, and risk isn’t the same for every patient.
Know What’s Normal for You
Some swelling, warmth and discomfort can be perfectly normal after ankle surgery. That’s precisely what makes DVT tricky.
Pay attention to changes: swelling that suddenly increases, one calf becoming noticeably larger than the other, new calf pain or tenderness, unusual warmth or redness, or symptoms that seem out of proportion to what your ankle has been doing.
If you develop symptoms that could indicate a DVT, seek medical evaluation the same day. Don't wait to see whether they go away. A DVT can't be reliably diagnosed by looking at your leg or checking symptoms alone; imaging, usually an ultrasound, may be needed.
[i] Source: Park YU, et al. “Incidence and Risk Factors of Deep Vein Thrombosis after Foot and Ankle Surgery.” Clinics in Orthopedic Surgery. 2024.