Subtalar fusion (arthrodesis) joins the heel bone to the talus to stop painful movement in an arthritic subtalar joint, just below the ankle. It can be done through an open incision or arthroscopically (keyhole). Both work well for arthritis without major deformity; arthroscopic fusion may heal a little faster with fewer wound problems, while open surgery is needed to correct deformity or add bone graft.
This guide from the foot and ankle team at Sports Orthopedics Institute, Bengaluru explains who needs subtalar fusion, how the two approaches compare, and what recovery involves.
Key takeaways
- Most common reason: arthritis after a heel bone (calcaneus) fracture.
- Both approaches work: union rates are around 90–96% in reviews.
- Arthroscopic fusion suits arthritis without significant deformity and may give faster union and return to activity.
- Open fusion is needed for deformity correction, height restoration with bone graft, and many revisions.
- Smoking is the biggest risk for the bones failing to join.
- Recovery: about 6 weeks of protected weight-bearing and 3–4 months until fusion is solid; full recovery can take up to a year.
The Subtalar Joint and Who Needs Fusion
The subtalar joint sits between the talus and the heel bone. It lets your foot tilt in and out, helping you walk on uneven ground. When it becomes arthritic, walking – especially on slopes and rough surfaces – becomes painful.
Common reasons for fusion
- Arthritis after a heel bone fracture – the most common reason
- Wear-and-tear (osteo)arthritis
- Inflammatory arthritis, such as rheumatoid arthritis
- Advanced adult flatfoot with a stiff, arthritic hindfoot
- Tarsal coalition (an abnormal bony or fibrous bridge between bones) that has failed other treatment
- Chronic instability of the joint
Typical symptoms
Pain below and in front of the outer ankle bone, worse on uneven ground, stairs and slopes; stiffness; and swelling around the heel.
Try These First
- Supportive shoes and orthotics to limit hindfoot movement
- An ankle brace or custom ankle-foot orthosis
- Activity changes – walking on even ground, cycling, swimming
- Anti-inflammatory painkillers
- Image-guided steroid injection into the subtalar joint, which also helps confirm the joint is the source of pain
Fusion is considered when pain remains disabling despite these measures.
How the Operation Is Done
In both techniques, the surgeon removes the remaining cartilage from the joint surfaces down to healthy bone, positions the heel correctly, and fixes the bones together with one to three large screws so they heal as one.
|
|
Open fusion |
Arthroscopic fusion |
|---|---|---|
|
Access |
One incision on the outer side of the foot (or the back, for complex cases) |
Two or three small portals, usually from the back with you lying face down, or from the side |
|
Best for |
Deformity correction, bone graft to restore heel height, revision surgery, removal of old hardware |
Arthritis without significant deformity or bone loss |
|
Bone graft |
Easy to add |
Limited |
|
Wound |
Larger scar; more wound and nerve risk |
Small scars |
|
Surgeon skill |
Widely performed |
Technically demanding; needs arthroscopic expertise |
When the heel has collapsed
After a badly healed heel fracture, the heel may have lost height, causing ankle impingement and a flattened talus. A distraction bone-block fusion places a wedge of bone graft into the joint to restore height. This is an open operation, usually through the back of the heel.
Arthroscopic vs Open: What the Evidence Shows
For arthritis without major deformity, both approaches give good results. Arthroscopic fusion shows a trend towards faster union and fewer complications, but the evidence is not yet strong enough to declare it superior.
Systematic review comparing the two
A 2023 systematic review of 22 studies (978 patients: 310 arthroscopic, 668 open) found (J ISAKOS, 2023):
|
Outcome |
Arthroscopic |
Open |
|---|---|---|
|
Union rate |
95.5% |
90.7% |
|
Average time to union |
12.2 weeks |
15.5 weeks |
|
Overall complications |
13.1% |
20.3% |
|
Most common complication |
Hardware-related |
Hardware-related |
Arthroscopic fusion also showed a larger average improvement in function scores. However, the authors concluded the evidence was inconclusive for recommending one technique over the other, because the studies were mostly non-randomised and arthroscopic cases tend to be less complex (PubMed).
Comparative and randomised studies
- Randomised study (54 patients): both techniques significantly improved pain and function, with no significant difference in short-term outcomes or complications; the arthroscopic group returned to activity and fused faster (Foot Ankle Orthop, 2020).
- Comparative study (129 feet): both techniques improved pain and function. Hardware symptoms were more common after arthroscopic fusion, while sural nerve injury was more common after open fusion (JBJS, 2016).
- Arthroscopic-only review (409 operations): union in 95.8% at an average of 11.9 weeks; non-union 4.3%; infection 0.8% (JBJS Rev, 2021).
Bottom line: if you have subtalar arthritis without significant deformity or bone loss, arthroscopic fusion is a good option in experienced hands. If your heel needs realigning or rebuilding, open surgery is the right choice.
Results and Complications
Most people get substantial pain relief, but fusion is a significant operation and the bones do not always join.
Will the bones fuse?
Union rates in modern reviews are around 90–96%. In a large series of 184 isolated subtalar fusions, union occurred in 84% overall – 92% in non-smokers but only 73% in smokers – and was also lower after revision surgery, with dead (avascular) bone, or next to a previous ankle fusion. Once these groups were excluded, union rose to 96% (Easley et al., JBJS 2000).
Other possible complications
|
Complication |
Notes |
|---|---|
|
Prominent or painful screws |
The most common complication; screws can be removed once fused |
|
Non-union |
Bones fail to join; may need revision with bone graft |
|
Nerve irritation |
Numbness or pain on the outer foot (sural nerve), more with open surgery |
|
Wound problems or infection |
Less common with arthroscopic surgery; higher with smoking and diabetes |
|
Malalignment |
Heel fused tilted too far in or out |
|
Arthritis in neighbouring joints |
The ankle and midfoot take more load over the years |
Living with a fused subtalar joint
The ankle still moves up and down, so most people walk normally on flat ground. Uneven surfaces, slopes and side-to-side movements feel stiffer. Low-impact sports such as cycling, swimming, golf and walking are usually possible; high-impact sports may be limited.
Recovery Timeline
|
Time |
What happens |
|---|---|
|
Weeks 0–2 |
Splint or boot; no weight on the foot; keep it elevated; stitches out around 2 weeks |
|
Weeks 2–6 |
Boot; non-weight-bearing or touch-down only, depending on your surgeon; ankle and toe exercises |
|
Weeks 6–12 |
X-rays show early healing; gradual weight-bearing in the boot, then into a supportive shoe |
|
Months 3–4 |
Fusion becoming solid (a CT scan may be used to confirm); walking normally; physiotherapy for strength and balance |
|
Months 6–12 |
Return to most activities and recreational sport; swelling continues to settle |
Stop smoking before surgery and throughout healing – it is the single biggest thing you can do to help the bones fuse.
Driving: after left foot surgery, usually once off strong painkillers in an automatic car; after right foot surgery, usually not until you are out of the boot and can brake safely, often around 8–12 weeks.
Questions to Ask Your Surgeon
- Is the subtalar joint definitely the source of my pain?
- Do I need deformity correction or bone graft, or is arthroscopic fusion an option?
- How many arthroscopic and open subtalar fusions do you perform?
- How long will I be non-weight-bearing?
- What can I do to improve my chances of the bones fusing?
How Sports Orthopedics Institute Can Help
Our foot and ankle team in HSR Layout, Bengaluru offers both arthroscopic and open subtalar fusion, including complex reconstruction after heel fractures, with CT-based planning and structured rehabilitation.
Call +91 6364538660 or +91 9008520831 to book a consultation.
Frequently Asked Questions
What is subtalar arthrodesis?
An operation that permanently joins the talus and heel bone so the painful, arthritic subtalar joint no longer moves.
Is arthroscopic subtalar fusion better than open surgery?
For arthritis without major deformity, studies suggest arthroscopic fusion may heal faster with fewer complications, but a systematic review found the evidence inconclusive. Open surgery is needed for deformity correction or bone grafting.
What is the success rate?
Bones fuse in around 90–96% of cases in recent reviews. Smoking, revision surgery and poor bone quality lower the chance of union.
How long until I can walk?
Usually about 6 weeks of protected weight-bearing, then gradual walking in a boot, with most people in normal shoes by about 3 months.
Will I walk normally afterwards?
On flat ground, most people walk well because the ankle still moves up and down. Uneven ground and slopes feel stiffer.
Can I play sport after subtalar fusion?
Low-impact activities are usually fine. Running and pivoting sports may be possible for some, but expect some limitation.
Will the screws need removing?
Only if they cause discomfort, which is fairly common. They can be removed once the fusion is solid.
What is the difference between subtalar fusion and ankle fusion?
Subtalar fusion joins the joint below the ankle and keeps up-and-down ankle movement. Ankle fusion joins the main ankle joint and keeps side-to-side subtalar movement.
References
- Silvampatti SR, et al. Inconclusive evidence that arthroscopic techniques yield better outcomes than open techniques for subtalar arthrodesis: a systematic review. J ISAKOS, 2023;8(2):114–121.
- Rungprai C, et al. Outcomes and complications of open versus posterior arthroscopic subtalar arthrodesis: a prospective randomized multicenter study. Foot & Ankle Orthopaedics, 2020.
- Rungprai C, et al. Outcomes and complications after open versus posterior arthroscopic subtalar arthrodesis in 121 patients. J Bone Joint Surg Am, 2016;98(8):636–646.
- Isolated arthroscopic-assisted subtalar fusion: a systematic review. JBJS Reviews, 2021.
- Easley ME, et al. Isolated subtalar arthrodesis. J Bone Joint Surg Am, 2000;82(5):613–624.
Disclaimer: This article is for general information and does not replace advice from a qualified foot and ankle surgeon.