Osteoarthritis (OA) of the subtalar joint is a degenerative condition that affects the joint located just below the ankle, where the talus bone meets the calcaneus (heel bone). This joint plays a key role in foot motion, especially when walking on uneven surfaces or turning the foot side to side. When the cartilage in this joint wears down, it can cause pain, stiffness, and difficulty with walking or standing. Subtalar joint OA is often linked to prior trauma and can significantly impact daily function and quality of life.
How Common It Is and Who Gets It? (Epidemiology)
Subtalar joint osteoarthritis is less common than arthritis in larger joints such as the knee or hip, but it is a significant cause of chronic foot pain. It is most often seen in middle-aged and older adults, especially those who have had previous foot or ankle injuries. Studies suggest that up to 60% of cases are related to prior fractures, particularly calcaneal fractures. Individuals with occupations or activities involving repetitive impact on the feet, such as athletes, laborers, or military personnel, are at higher risk.
Why It Happens – Causes (Etiology and Pathophysiology)
The subtalar joint is vulnerable to degeneration because of its complex structure and its role in absorbing shock during walking. The most common cause of OA in this joint is post-traumatic osteoarthritis (PTOA), which develops after an injury such as a fracture or severe sprain. Trauma damages the cartilage and alters joint mechanics, triggering inflammation that accelerates cartilage breakdown. Over time, this leads to loss of joint space, formation of bone spurs (osteophytes), and chronic pain. Less commonly, subtalar OA can develop from long-standing foot deformities, inflammatory conditions, or abnormal joint loading.
How the Body Part Normally Works? (Relevant Anatomy)
The subtalar joint connects the talus bone of the ankle with the calcaneus bone of the heel. It allows inversion and eversion—the side-to-side movements that help the foot adapt to uneven surfaces and absorb shock. The joint is supported by strong ligaments, a joint capsule, and surrounding muscles, all of which work together to maintain stability and smooth motion. Healthy cartilage in the subtalar joint cushions the bones and allows them to glide effortlessly during walking and running.
What You Might Feel – Symptoms (Clinical Presentation)
Patients with subtalar joint OA usually report deep, aching pain in the back or outer side of the foot, especially when walking or standing for long periods. The pain often worsens on uneven surfaces and may improve with rest. Stiffness, swelling, and tenderness in the rearfoot are common. Some patients experience instability, describing a sensation of the foot “giving way.” As the condition progresses, reduced mobility can make walking difficult and may lead to compensatory pain in other joints of the foot or ankle.
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis begins with a detailed medical history and physical examination. The doctor checks for tenderness, swelling, restricted motion, and instability. Weight-bearing X-rays are typically the first imaging test used to assess joint space narrowing and bone changes. In complex cases, CT scans or weight-bearing CT (WBCT) imaging provide a more detailed view of the joint surfaces and alignment. MRI may be used if soft tissue or early cartilage injury is suspected.
Classification
Subtalar joint osteoarthritis can be classified as:
- Primary (Idiopathic) OA – Occurs without a clear cause, often related to aging and wear-and-tear.
- Secondary (Post-Traumatic) OA – Develops after fractures, sprains, or alignment changes in the foot.
Severity may also be graded based on imaging findings: mild (cartilage thinning), moderate (joint space loss and osteophytes), or severe (joint destruction and deformity).
Other Problems That Can Feel Similar (Differential Diagnosis)
Several conditions can mimic subtalar joint OA, including sinus tarsi syndrome, peroneal tendonitis, tarsal coalition, posterior tibial tendon dysfunction, or midfoot arthritis. Careful examination and imaging help distinguish between these conditions and confirm the diagnosis.
Treatment Options
Non-Surgical Care
Conservative management is the first line of treatment for mild to moderate subtalar joint OA.
- Orthotic Management: Custom orthotics and supportive footwear can offload pressure on the subtalar joint, correct alignment, and improve comfort.
- Physical Therapy: Strengthening and flexibility exercises help maintain joint mobility and support surrounding structures. Balance and gait training may also reduce stress on the joint.
- Medication: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed for pain and swelling. Corticosteroid injections can provide short-term relief during flare-ups, but repeated use is discouraged due to potential side effects.
Surgical Care
When conservative measures no longer control symptoms, surgical treatment may be recommended.
- Arthrodesis (Fusion): The most common surgical option for advanced OA. The joint surfaces are fused together to eliminate pain, though motion at the joint is permanently lost. This may slightly alter gait but typically relieves pain effectively.
- Subtalar Joint Replacement: A newer, less common procedure that replaces the damaged joint with an artificial implant. It preserves some motion and may improve function in selected patients.
- Arthroscopic Debridement: In early or moderate OA, removing loose cartilage or bone spurs with a small camera can relieve pain and improve range of motion.
- Corrective Osteotomy: For patients with alignment issues contributing to OA, bone realignment may help reduce uneven joint loading and slow progression.
Recovery and What to Expect After Treatment
Recovery depends on the treatment approach. After conservative care, improvement may take several weeks of consistent therapy. Following fusion surgery, patients typically spend 6–8 weeks in a cast or boot without weight-bearing, followed by gradual return to activity over several months. Full recovery may take up to a year. After replacement surgery, recovery is often faster, though rehabilitation is still essential. Most patients can expect meaningful pain relief and better walking stability after treatment.
Possible Risks or Side Effects (Complications)
Complications may include infection, nerve irritation, stiffness, or continued pain. Fusion surgery can lead to increased stress on nearby joints, potentially causing arthritis elsewhere in the foot. Replacement surgery carries risks of implant loosening or failure. Arthroscopic and osteotomy procedures, while less invasive, still carry risks of incomplete pain relief or recurrence.
Long-Term Outlook (Prognosis)
With proper treatment, most patients achieve significant pain reduction and improved function. Those who undergo fusion often have lasting relief but may notice reduced flexibility. Subtalar joint replacements show promising short- to mid-term results, but long-term durability remains under study. Early diagnosis and management can slow progression and help preserve mobility.
Out-of-Pocket Costs
Medicare
CPT Code 28725 – Subtalar Joint Arthrodesis (Fusion): $182.74
CPT Code 29894 – Arthroscopic Debridement of Subtalar Joint: $119.24
CPT Code 28300 – Calcaneal Osteotomy for Alignment Correction: $153.01
Medicare Part B typically covers 80% of the approved cost for these procedures once your annual deductible has been met, leaving you responsible for the remaining 20%. Supplemental Insurance plans such as Medigap, AARP, or Blue Cross Blue Shield generally cover the remaining 20%, minimizing or eliminating out-of-pocket expenses for Medicare-approved surgeries. These plans are designed to coordinate with Medicare to close the coverage gap and reduce financial responsibility.
If you have Secondary Insurance, such as TRICARE, an Employer-Based Plan, or Veterans Health Administration coverage, it acts as a secondary payer. These plans typically cover any remaining balance, including coinsurance or small deductibles, which generally range from $100 to $300, depending on your plan and provider network.
Workers’ Compensation
If your subtalar joint arthritis is related to a work-related injury or repetitive stress, Workers’ Compensation will cover all treatment costs, including surgery, rehabilitation, and follow-up care. You will not have any out-of-pocket expenses, as the employer’s insurance carrier directly pays for all approved treatments.
No-Fault Insurance
If your subtalar joint arthritis or related condition is linked to an automobile accident, No-Fault Insurance will typically cover the full cost of treatment, including arthroscopy, osteotomy, or fusion. The only potential out-of-pocket cost may be a small deductible or co-payment based on your policy.
Example
Steven Rodriguez was diagnosed with osteoarthritis of the subtalar joint causing chronic hindfoot pain. He underwent subtalar fusion (CPT 28725) with an estimated Medicare out-of-pocket cost of $182.74. Since Steven had supplemental insurance through Blue Cross Blue Shield, his remaining balance was fully covered, leaving him with no out-of-pocket expenses for the surgery.
Frequently Asked Questions (FAQ)
Q. What is osteoarthritis of the subtalar joint?
A. Osteoarthritis of the subtalar joint is a degenerative condition where the cartilage in the joint between the talus and calcaneus bones wears down, leading to pain, stiffness, and reduced mobility.
Q. What causes osteoarthritis of the subtalar joint?
A. It is often caused by previous injuries to the joint, such as fractures or repeated sprains, and can also result from normal wear and tear over time.
Q. What are the symptoms of subtalar joint osteoarthritis?
A. Symptoms include pain in the heel or below the ankle, stiffness, difficulty walking on uneven surfaces, and reduced range of motion in the foot.
Q. How is subtalar joint osteoarthritis diagnosed?
A. Diagnosis typically involves a physical examination, patient history, and imaging studies like X-rays or MRIs to assess the condition of the joint and surrounding structures.
Q. What nonsurgical treatments are available for subtalar joint osteoarthritis?
A. Nonsurgical treatments include anti-inflammatory medications, physical therapy, orthotics, ankle braces, and activity modification to reduce stress on the joint.
Q. When is surgery considered for subtalar joint osteoarthritis?
A. Surgery is considered when conservative treatments fail to relieve symptoms and the pain significantly interferes with daily activities.
Q. What surgical options exist for subtalar joint osteoarthritis?
A. The main surgical treatment is subtalar joint fusion, which involves removing the damaged cartilage and fusing the bones together to eliminate pain.
Q. What is the recovery process like after subtalar joint fusion surgery?
A. Recovery includes a period of non-weight bearing with the use of crutches or a walker, followed by gradual return to weight-bearing activities with physical therapy.
Q. Can patients return to normal activities after subtalar joint fusion?
A. Many patients can return to normal activities, although they may experience some loss of foot motion, especially on uneven surfaces.
Q. What is the long-term outlook for patients with subtalar joint osteoarthritis?
A. With proper management, including conservative or surgical treatment, patients can achieve significant pain relief and improved function.
Q. Can subtalar arthritis heal on its own?
A. No, once cartilage damage occurs, it cannot regenerate. However, symptoms can be controlled with conservative care.
Q. Will fusion surgery make walking difficult?
A. Fusion removes motion at the subtalar joint but usually allows near-normal walking once healed.
Q. Can orthotics really help?
A. Yes, orthotics can significantly reduce pain by correcting alignment and decreasing stress on the affected joint.
Q. Is subtalar joint replacement safe?
A. It’s safe for selected patients, though it’s less common and long-term results are still being evaluated.
Summary and Takeaway
Subtalar joint osteoarthritis causes pain and stiffness in the rearfoot, often due to previous trauma or repetitive stress. Conservative treatments—orthotics, physical therapy, and medication—can help in early stages. In more advanced cases, surgical fusion or replacement offers reliable pain relief. Early diagnosis, consistent care, and attention to alignment are key to maintaining mobility and quality of life.
Clinical Insight & Recent Findings
A 2025 case report by Kanemitsu et al. described a patient who developed subtalar joint osteoarthritis following a missed fracture of the lateral process of the talus (FLPT) — a rare injury often overlooked, particularly in cases misinterpreted as ankle sprains.
The 44-year-old man’s untreated fracture progressed to painful nonunion and subtalar OA. After surgical fixation with screws and bone grafting, his pain and joint space markedly improved, and he returned to normal activity within a year.
The report emphasizes that early recognition and surgical stabilization of lateral talar process fractures are crucial to prevent secondary osteoarthritis and restore joint stability. (“A study showed that repairing a missed ankle bone fracture (the lateral talus) can reverse subtalar arthritis and relieve pain — see PubMed.”)
Who Performs This Treatment? (Specialists and Team Involved)
Treatment is usually managed by an orthopedic foot and ankle surgeon. The care team may also include a podiatrist, physical therapist, anesthesiologist, and rehabilitation specialists. Together, they ensure safe surgery, optimal pain management, and effective rehabilitation.
When to See a Specialist?
You should see a specialist if foot or ankle pain lasts more than a few weeks, interferes with walking, or does not improve with rest or over-the-counter medication. A specialist can perform imaging studies and recommend tailored treatment options.
When to Go to the Emergency Room?
Go to the emergency room if you experience sudden, severe foot pain after an injury, an obvious deformity, inability to bear weight, or signs of infection such as redness, swelling, and fever.
What Recovery Really Looks Like?
Recovery may involve a period of restricted weight-bearing, physical therapy, and gradual return to activity. Mild soreness, stiffness, and swelling are normal for several months. Consistent rehabilitation and supportive footwear improve long-term results.
What Happens If You Ignore It?
Ignoring subtalar joint OA can lead to worsening pain, reduced mobility, and deformity. Untreated OA may cause secondary arthritis in nearby joints and long-term gait changes that affect knees, hips, and the lower back.
How to Prevent It?
Wearing supportive shoes, maintaining a healthy weight, and avoiding repetitive high-impact activities help protect the subtalar joint. Treating ankle injuries promptly and using orthotics when needed can reduce long-term risk.
Nutrition and Bone or Joint Health
A diet rich in calcium, vitamin D, and protein supports bone and cartilage health. Staying hydrated and maintaining a balanced diet can reduce inflammation and aid healing after surgery or injury.
Activity and Lifestyle Modifications
Patients should favor low-impact exercises such as swimming or cycling instead of running or jumping. Using supportive footwear and avoiding uneven terrain can help manage symptoms and prevent progression. With proper care, most individuals can return to daily activities with improved comfort and function.
Dr. Mo Athar
