Frozen ankle, medically termed adhesive capsulitis of the ankle (ACA), is a rare but debilitating condition that causes stiffness, pain, and a progressive loss of motion in the ankle joint. It results from inflammation and thickening of the joint capsule, which leads to restricted movement and significant functional limitation. Although adhesive capsulitis is well known in the shoulder, its occurrence in the ankle is uncommon and often underrecognized.
How Common It Is and Who Gets It? (Epidemiology)
Adhesive capsulitis of the ankle is extremely rare compared to frozen shoulder, with only scattered case reports and small studies in the literature. Most cases are diagnosed in adults aged 40 to 70 years, with no significant gender predominance. The condition may occur idiopathically (without a clear cause) but is often secondary to trauma, surgery, or systemic conditions such as diabetes, hypothyroidism, or gout. Individuals with repeated ankle sprains, fractures, or prolonged immobilization are more likely to develop ACA.
Why It Happens – Causes (Etiology and Pathophysiology)
The exact cause of frozen ankle remains unclear, but both inflammatory and fibrotic mechanisms play central roles. Inflammation within the joint capsule leads to thickening and fibrosis, which restricts normal motion.
Common triggers include:
- Trauma or surgery: Recurrent ankle sprains, fractures, or previous operations cause capsular scarring.
- Metabolic disorders: Diabetes and hypothyroidism increase the risk of capsular fibrosis due to altered collagen turnover and microvascular changes.
- Prolonged immobilization: After injury or casting, restricted joint movement can accelerate capsule contracture.
Microscopically, the joint capsule shows fibroblastic proliferation, increased collagen deposition, and elevated inflammatory mediators such as interleukin (IL)-1, IL-6, and transforming growth factor-beta (TGF-β).
How the Body Part Normally Works? (Relevant Anatomy)
The ankle joint (tibiotalar joint) is a synovial hinge joint formed by the tibia, fibula, and talus. It allows for dorsiflexion (upward movement) and plantarflexion (downward movement). The joint capsule surrounds the articulation and provides stability while allowing smooth motion. In frozen ankle, inflammation and fibrosis of this capsule lead to adhesions and decreased joint space, resulting in pain and rigidity.
What You Might Feel – Symptoms (Clinical Presentation)
Patients with adhesive capsulitis of the ankle typically report:
- Gradual onset of pain in the front, back, or sides of the ankle.
- Progressive stiffness and restricted range of motion, particularly dorsiflexion and plantarflexion.
- Aching discomfort that worsens with movement or prolonged standing.
- Muscle atrophy around the ankle from disuse.
- Difficulty walking or performing daily activities such as climbing stairs.
Symptoms usually evolve through three stages:
- Freezing phase – Increasing pain and gradual stiffness.
- Frozen phase – Persistent stiffness with less pain.
- Thawing phase – Slow improvement in range of motion over months.
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis is primarily clinical, based on progressive stiffness and loss of both active and passive ankle motion.
- Physical exam: Reveals restricted movement in all planes, often accompanied by mild swelling and tenderness.
- Arthrography: Considered the gold standard for diagnosis; demonstrates decreased joint volume and restricted capsule expansion.
- MRI: Helps rule out alternative diagnoses (ligament tears, osteoarthritis, or fracture) and may show capsular thickening or synovitis.
- Ultrasound: Useful to assess soft-tissue inflammation or fibrotic adhesions.
X-rays are usually normal but may be performed to exclude bony causes of stiffness.
Classification
Frozen ankle can be classified based on cause and chronicity:
- Primary (idiopathic): No identifiable trigger.
- Secondary: Associated with trauma, surgery, systemic disease, or prolonged immobilization.
It can also be staged clinically as:
- Freezing stage – Painful inflammation predominates.
- Frozen stage – Pain decreases, but stiffness peaks.
- Thawing stage – Gradual recovery of motion.
Other Problems That Can Feel Similar (Differential Diagnosis)
- Post-traumatic arthritis
- Chronic ankle instability
- Osteochondral lesions of the talus
- Tarsal coalition
- Synovitis due to gout or rheumatoid arthritis
Accurate imaging and clinical correlation help distinguish ACA from these conditions.
Treatment Options
Non-Surgical Care
Most cases respond to conservative management:
- Physical Therapy: The cornerstone of treatment, focusing on gentle stretching, joint mobilization, and range-of-motion exercises to maintain mobility.
- Extracorporeal Shock Wave Therapy (ESWT): Promotes pain relief and stimulates tissue regeneration.
- Corticosteroid Injections: Reduce intra-articular inflammation and pain, particularly in early stages.
- Laser Therapy: Combined with exercise, can enhance flexibility and decrease stiffness.
- NSAIDs: Help control pain and inflammation.
- Activity modification: Reducing high-impact or repetitive ankle strain prevents symptom worsening.
Surgical Care
Surgery is indicated when conservative measures fail after several months.
- Arthroscopic Capsular Release: Minimally invasive removal of fibrotic tissue and adhesions to restore motion.
- Synovectomy: Removes inflamed synovial lining contributing to stiffness.
- Open capsulotomy: Reserved for severe, refractory cases.
Postoperative physical therapy is critical to maintaining motion and preventing recurrence.
Recovery and What to Expect After Treatment
Improvement can be gradual and may take 6–12 months. Early rehabilitation is vital for success. After surgery, patients usually regain functional range of motion within 3–6 months with dedicated physical therapy. Persistent stiffness may occur if therapy is delayed or discontinued prematurely.
Possible Risks or Side Effects (Complications)
- Persistent stiffness or recurrence of capsulitis.
- Postoperative infection or swelling.
- Pain due to over-aggressive stretching or manipulation.
- Rarely, nerve irritation or instability after arthroscopic release.
Long-Term Outlook (Prognosis)
The prognosis for frozen ankle is generally good with early recognition and treatment. Most patients achieve significant improvement in mobility and pain reduction. However, recovery may be incomplete in cases with severe fibrosis or systemic comorbidities such as diabetes.
Out-of-Pocket Costs
Medicare and most insurance plans typically cover physical therapy, corticosteroid injections, and arthroscopic procedures.
- CPT Code 29898 – Arthroscopic capsular release: $130.96
- CPT Code 97110 – Physical therapy, therapeutic exercise: $50.00 per session
- CPT Code 20610 – Corticosteroid injection, major joint: $90.00
Secondary insurance, such as Medigap or BCBS, usually covers the remaining costs.
Frequently Asked Questions (FAQ)
Q. What is a frozen ankle?
A. A frozen ankle refers to significant stiffness and loss of motion in the ankle joint, often due to arthritis, trauma, or prolonged immobilization.
Q. What are the main causes of frozen ankle?
A. Frozen ankle is commonly caused by post-traumatic arthritis, degenerative arthritis, or prolonged immobility after an injury or surgery.
Q. What are the symptoms of a frozen ankle?
A. Symptoms include stiffness, pain, decreased range of motion, and difficulty with walking or performing daily activities.
Q. How is a frozen ankle diagnosed?
A. Diagnosis involves clinical evaluation and imaging studies such as X-rays or CT scans to assess joint degeneration and bone alignment.
Q. What non-surgical treatments are available for frozen ankle?
A. Non-surgical options include physical therapy, bracing, anti-inflammatory medications, and cortisone injections.
Q. When is surgery considered for frozen ankle?
A. Surgery is considered when conservative treatments fail and symptoms significantly affect quality of life or function.
Q. What surgical options are available for frozen ankle?
A. Surgical treatments may include arthroscopic debridement, ankle distraction arthroplasty, or ankle fusion depending on the severity of the condition.
Q. What is ankle fusion?
A. Ankle fusion is a surgical procedure that joins the bones of the ankle joint to eliminate pain from arthritis and improve stability.
Q. What is the goal of ankle fusion surgery?
A. The goal is to relieve pain and improve function by eliminating motion at the arthritic joint.
Q. What is ankle distraction arthroplasty?
A. Ankle distraction arthroplasty is a joint-preserving procedure where an external fixator is used to temporarily unload the ankle joint to stimulate cartilage repair.
Q. What is arthroscopic debridement?
A. Arthroscopic debridement involves removing inflamed tissue, bone spurs, or loose bodies from the ankle joint using a minimally invasive technique.
Q. What is the recovery like after surgery for frozen ankle?
A. Recovery depends on the type of surgery but typically involves a period of non-weight bearing, physical therapy, and gradual return to activity.
Q. Can a frozen ankle be prevented?
A. Prevention includes early mobilization after injury, proper rehabilitation, and management of arthritis or joint degeneration.
Summary and Takeaway
Frozen ankle (adhesive capsulitis of the ankle) is a rare but serious cause of stiffness and pain due to inflammation and fibrosis of the ankle joint capsule. It often follows trauma, immobilization, or systemic disease. Early recognition and non-surgical management with physical therapy, ESWT, and corticosteroid injections are highly effective. Refractory cases may require arthroscopic capsular release. A structured rehabilitation program remains essential for recovery and long-term mobility.
Clinical Insight & Recent Findings
A 2023 review published in Biomedicines explored adhesive capsulitis of the ankle (“frozen ankle”) as a rare but disabling condition causing progressive stiffness, pain, and loss of movement. The study emphasized that inflammation, fibrosis, and metabolic factors like insulin resistance and chronic low-grade inflammation all contribute to the disease process.
Early diagnosis through arthrography and targeted therapies—such as extracorporeal shock wave therapy, stretching, corticosteroid injections, and physical therapy—are key to improving outcomes.
The authors also highlighted emerging interest in biologic and regenerative treatments, including stem cell and platelet-rich plasma (PRP) therapy, and called for standardized diagnostic criteria and greater research into how lifestyle factors, such as immobility and metabolic health, may influence recovery. (“Study on the pathophysiology and treatment of frozen ankle – see PubMed.“)
Who Performs This Treatment? (Specialists and Team Involved)
Frozen ankle is typically managed by orthopedic foot and ankle surgeons, podiatrists, and physical therapists. Rheumatologists and endocrinologists may assist in cases with systemic associations.
When to See a Specialist?
Consult a specialist if you experience persistent stiffness, pain, or limited ankle motion for more than 4–6 weeks after an injury or immobilization.
When to Go to the Emergency Room?
Emergency evaluation is rarely needed unless the stiffness follows acute trauma, severe swelling, infection, or suspected fracture.
What Recovery Really Looks Like?
Recovery requires commitment to a consistent rehabilitation plan. Gradual gains in mobility and pain relief occur over several months. Surgical patients must continue therapy postoperatively to maintain improvement.
What Happens If You Ignore It?
Untreated frozen ankle can lead to chronic stiffness, permanent loss of motion, and functional disability. Early treatment offers the best chance for full recovery.
How to Prevent It?
- Begin gentle ankle exercises soon after injury or surgery (as medically cleared).
- Maintain joint mobility and avoid prolonged immobilization.
- Manage metabolic disorders such as diabetes and hypothyroidism.
- Use supportive footwear and maintain an active lifestyle to promote circulation.
Nutrition and Bone or Joint Health
A diet rich in antioxidants, omega-3 fatty acids, and vitamins C, D, and E supports joint health and reduces inflammation. Adequate hydration and blood sugar control also play key roles in preventing fibrosis.
Activity and Lifestyle Modifications
Dr. Mo Athar
