Posterior Tibial Tendon Dysfunction: An Overview
Posterior Tibial Tendon Dysfunction (PTTD), also known as posterior tibial tendon insufficiency or adult-acquired flatfoot, is a progressive condition that weakens or damages the posterior tibial tendon—the primary structure that supports the arch of the foot. When this tendon becomes inflamed or torn, the arch gradually collapses, leading to flatfoot deformity, pain, and impaired function. Without treatment, PTTD can progress to advanced deformity and arthritis, limiting mobility and daily activity.
How Common It Is and Who Gets It? (Epidemiology)
PTTD most commonly affects middle-aged adults, particularly women over the age of 40. The condition is associated with repetitive strain, obesity, diabetes, hypertension, and previous ankle trauma. It is a leading cause of adult-acquired flatfoot and may occur in one or both feet, though it typically begins on one side.
Why It Happens – Causes (Etiology and Pathophysiology)
PTTD develops gradually as the posterior tibial tendon undergoes degeneration from chronic overuse. Repetitive strain leads to small tears, reduced elasticity, and eventual failure of the tendon to support the arch. This imbalance allows the foot to roll inward (valgus) and flatten over time. As the deformity progresses, surrounding ligaments—especially the spring ligament complex—also weaken, worsening the collapse of the arch.
How the Body Part Normally Works? (Relevant Anatomy)
The posterior tibial tendon originates along the back of the tibia and fibula, running behind the medial ankle bone (medial malleolus) before attaching to the navicular bone, cuneiforms, and metatarsals. It works together with ligaments and muscles to stabilize the foot and support the medial arch. The area behind the medial malleolus has limited blood flow, making it prone to degeneration and slow healing.
What You Might Feel – Symptoms (Clinical Presentation)
In early stages, patients often experience pain and swelling along the inside of the ankle or foot. As the condition advances, the arch flattens and the foot begins to roll inward. The pain may later shift to the outside of the ankle due to joint stress.
Common symptoms include:
- Pain and tenderness along the inner ankle or arch
- Swelling or warmth around the tendon
- Flattening of the foot and inward rolling of the ankle
- Difficulty standing on tiptoes or walking long distances
- The “too many toes” sign, visible when more than two toes are seen from behind due to forefoot abduction
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis involves a physical examination focusing on arch shape, gait, and strength. The single-leg heel raise test is often used—patients with PTTD may be unable to lift their heel off the ground on the affected side.
Imaging tests may include:
- X-rays to identify arch collapse or joint degeneration
- Ultrasound to evaluate tendon thickening or partial tears
- MRI to assess tendon integrity and guide surgical planning
Classification
The Johnson and Strom classification system divides PTTD into four stages:
- Stage I: Tendon inflammation without deformity
- Stage II: Partial tendon rupture with flexible flatfoot
- Stage III: Rigid deformity with subtalar joint arthritis
- Stage IV: Involvement of the ankle joint with valgus tilt
Other Problems That Can Feel Similar (Differential Diagnosis)
Conditions that can mimic PTTD include:
- Tarsal tunnel syndrome
- Plantar fasciitis
- Medial ankle sprain
- Accessory navicular syndrome
- Rheumatoid or inflammatory arthritis
A careful history, physical exam, and imaging are used to distinguish between these conditions.
Treatment Options
Non-Surgical Care
Early treatment is key to preventing deformity.
- Rest and immobilization: Short-term casting or boot immobilization may reduce inflammation.
- Orthotic devices: Custom arch supports or ankle-foot orthoses (AFOs) relieve stress and realign the foot.
- Physical therapy: Stretching the Achilles tendon and strengthening the posterior tibial muscle improve function.
- Medications: NSAIDs help relieve pain and swelling.
- Shoe modifications: Supportive shoes with medial arch reinforcement prevent further strain.
Surgical Care
Surgery is considered when symptoms persist despite conservative management or when deformity progresses. Stage-specific procedures include:
- Stage I: Synovectomy (removal of inflamed tissue) if non-surgical measures fail.
- Stage II: Flexor digitorum longus (FDL) tendon transfer combined with calcaneal osteotomy to restore arch alignment.
- Stage III: Triple arthrodesis (fusion of subtalar, calcaneocuboid, and talonavicular joints) for rigid deformity.
- Stage IV: Fusion extending into the ankle or reconstruction of the deltoid ligament for advanced instability.
Recovery and What to Expect After Treatment
Recovery depends on the stage and treatment type. Non-surgical recovery may take several months with consistent bracing and therapy. After surgery, immobilization in a cast or boot lasts about six weeks, followed by progressive weight-bearing and physical therapy. Most patients regain walking comfort and stability, though some stiffness is common.
Possible Risks or Side Effects (Complications)
Possible complications include:
- Incomplete correction or recurrence of flatfoot
- Nerve irritation or wound problems after surgery
- Overload on nearby joints following fusion procedures
- Persistent stiffness or weakness
Long-Term Outlook (Prognosis)
With early diagnosis and treatment, patients can expect excellent outcomes and preservation of foot function. Advanced stages requiring fusion provide reliable pain relief but limit foot motion. Long-term success depends on maintaining a healthy weight, using supportive footwear, and following prescribed therapy.
Out-of-Pocket Costs
Medicare
CPT Code 27691 – Tendon Debridement or Transfer: $175.25
CPT Code 28300 – Calcaneal Osteotomy: $153.01
CPT Code 28304 – Lateral Column Lengthening: $191.57
CPT Code 28735 – Fusion Procedures: $181.60
CPT Code 27870 – Ankle Joint Fusion (Stage IV): $236.43
Medicare Part B covers 80% of approved amounts after the deductible. Supplemental plans such as Medigap, AARP, or Blue Cross Blue Shield typically cover the remaining 20%. Secondary insurance (e.g., employer-based, TRICARE, or Veterans Health Administration plans) often pays any remaining balance, leaving patients with little to no out-of-pocket costs.
Workers’ Compensation
If your PTTD developed from repetitive strain or injury at work, Workers’ Compensation pays for all medical, surgical, and rehabilitation costs with no out-of-pocket expense.
No-Fault Insurance
If caused by a motor vehicle accident, No-Fault Insurance covers the entire cost of care, including surgery and follow-up visits. The only potential cost is a small deductible or copayment stated in your policy.
Example
Angela Martinez developed severe PTTD causing collapse of her arch and pain when walking. She underwent a tendon transfer (CPT 27691) and calcaneal osteotomy (CPT 28300). Her estimated Medicare out-of-pocket cost was $175.25, but her Blue Cross Blue Shield supplemental plan covered the balance, leaving her with no personal expense.
Frequently Asked Questions (FAQ)
Q. What is the role of the posterior tibial tendon in foot function?
A. The posterior tibial tendon supports the medial longitudinal arch, assists in foot inversion, and contributes to overall foot stability during movement.
Q. How does the posterior tibial tendon become damaged in PTTD?
A. Repeated microtrauma over time leads to tendinosis, causing the tendon to lose elasticity and strength, eventually resulting in fibrotic tissue replacement.
Q. What is the “too many toes” sign in PTTD?
A. The “too many toes” sign refers to the visibility of more than two toes when viewed from behind, indicating foot deformity due to tendon dysfunction.
Q. Which imaging methods are used to diagnose PTTD?
A. Diagnosis involves imaging techniques such as X-rays, MRIs, CT scans, and ultrasounds to assess tendon integrity and foot alignment.
Q. What are common risk factors for developing PTTD?
A. Risk factors include obesity, diabetes, hypertension, previous foot or ankle trauma, aging (especially in women over 40), steroid use, and certain inflammatory conditions.
Q. What are the common symptoms of posterior tibial tendon dysfunction (PTTD)?
A. Symptoms include pain along the inside of the ankle, swelling, a flatfoot appearance, difficulty standing on tiptoe, and an altered gait due to the inability to support the arch properly.
Q. How is posterior tibial tendon dysfunction diagnosed?
A. PTTD is diagnosed through a physical examination, patient history, imaging tests such as X-rays or MRIs, and sometimes an ultrasound to evaluate the tendon’s condition and the foot’s structural alignment.
Q. Can PTTD affect both feet?
A. Yes, although PTTD typically affects one foot, it can sometimes develop in both feet, especially in individuals with underlying risk factors such as obesity or diabetes.
Q. What are the stages of posterior tibial tendon dysfunction?
A. PTTD is classified into four stages: Stage 1 involves tendon inflammation, Stage 2 includes tendon degeneration, Stage 3 features flatfoot deformity with misalignment, and Stage 4 occurs when arthritis develops in the ankle joint due to prolonged dysfunction.
Q. Is surgery always required for posterior tibial tendon dysfunction?
A. No, surgery is not always necessary. Nonoperative treatments like rest, orthotics, physical therapy, and anti-inflammatory medications are effective in the early stages, while surgery may be considered in advanced stages if conservative measures fail.
Q. How do custom orthotics help manage PTTD?
A. Custom orthotics help by providing support to the arch, redistributing weight away from the weakened tendon, and preventing further foot deformity, ultimately improving foot function and alleviating pain.
Q. Can physical therapy help with posterior tibial tendon dysfunction?
A. Yes, physical therapy can help strengthen the posterior tibial tendon and surrounding muscles, improve foot mechanics, and reduce pain through targeted exercises and stretches.
Q. What is the role of corticosteroid injections in treating PTTD?
A. Corticosteroid injections may be used to reduce inflammation and pain in the tendon, providing temporary relief, although they are not a long-term solution and should be used cautiously.
Q. How long does it take to recover from posterior tibial tendon dysfunction?
A. Recovery time varies depending on the stage of PTTD and the treatment method. Nonoperative management may take several months, while surgical recovery can last from 6 months to a year or longer.
Q. Can posterior tibial tendon dysfunction lead to permanent foot deformity?
A. If left untreated, PTTD can lead to permanent foot deformities, including flatfoot, misalignment of the ankle and toes, and progressive arthritis in the ankle joint, which can limit mobility.
Q. What causes posterior tibial tendon dysfunction?
A. Overuse, degeneration, or trauma to the tendon can cause it to weaken and lose function, leading to flatfoot deformity.
Q. Is PTTD the same as flatfoot?
A. PTTD is a leading cause of adult-acquired flatfoot, but not all flatfoot cases result from tendon dysfunction.
Q. Can PTTD heal without surgery?
A. Yes, early stages often improve with bracing, therapy, and orthotic support.
Q. How long does recovery take?
A. Mild cases improve within months of consistent care, while surgical recovery may take six to twelve months.
Q. Can both feet be affected?
A. While usually one foot is involved, bilateral cases can occur, especially in patients with systemic risk factors.
Summary and Takeaway
Posterior Tibial Tendon Dysfunction is a progressive condition that weakens the primary tendon supporting the arch of the foot. Early recognition, orthotic support, and rehabilitation can prevent severe deformity and arthritis. When advanced, surgical reconstruction or fusion may be necessary to restore alignment and relieve pain. Prompt evaluation and early intervention offer the best chance for maintaining foot stability and long-term mobility.
Clinical Insight & Recent Findings
A recent Journal of Biomechanics study compared individuals with PTTD to healthy participants while performing everyday movements like stepping up and down. Using 3D motion capture and force analysis, researchers found that those with PTTD had greater ankle eversion, midfoot dorsiflexion, and hip flexion, along with reduced muscle strength and control in stabilizing the lower limb.
These altered mechanics increase strain across the ankle, foot, and knee—factors that may worsen deformity and lead to joint complications over time.
The study emphasizes that step-based activities, not just walking, reveal key deficits that should guide tailored physical therapy and orthotic design for improved stability and function. (“Study on lower limb biomechanics in PTTD – see PubMed.“)
Who Performs This Treatment? (Specialists and Team Involved)
Treatment is provided by orthopedic foot and ankle surgeons or podiatric surgeons. Physical therapists, orthotists, and rehabilitation specialists assist in custom bracing, strengthening, and gait retraining during recovery.
When to See a Specialist?
You should see a specialist if you have persistent inner ankle pain, swelling, or flattening of your arch, especially if you cannot perform a single-leg heel raise or notice your foot rolling inward.
When to Go to the Emergency Room?
Seek urgent care if sudden severe pain, inability to bear weight, or significant swelling occurs—especially after trauma or suspected tendon rupture.
What Recovery Really Looks Like?
Recovery involves gradual improvement with therapy and bracing. Early stages recover with conservative measures, while post-surgical cases may require months of therapy before full function returns. Supportive footwear and orthotics remain essential long-term.
What Happens If You Ignore It?
Ignoring PTTD allows the deformity to progress, leading to permanent flatfoot, chronic pain, and joint arthritis. Advanced cases often require complex reconstructive or fusion surgery to restore stability.
How to Prevent It?
Maintain a healthy weight, wear supportive footwear, and avoid overuse. Regular stretching of the Achilles and strengthening of the posterior tibial tendon can reduce risk. Managing diabetes and hypertension also lowers tendon degeneration risk.
Nutrition and Bone or Joint Health
A nutrient-rich diet with adequate calcium, vitamin D, and protein supports tendon health and bone integrity. Staying hydrated and avoiding smoking helps maintain circulation to the foot and ankle.
Activity and Lifestyle Modifications
Engage in low-impact activities such as swimming or cycling to maintain fitness without overloading the tendon. Gradually increase exercise intensity, avoid walking barefoot on hard surfaces, and continue supportive bracing or orthotics as advised.
Dr. Mo Athar
