Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Hills, MI. Last updated April 2026.

What Is the Subtalar Joint?

The subtalar joint — also called the talocalcaneal joint — is located directly below and behind the ankle joint, between the talus (ankle bone) and calcaneus (heel bone). Unlike the ankle joint, which primarily moves the foot up and down (plantarflexion and dorsiflexion), the subtalar joint controls the side-to-side tilting and rotational motion of the hindfoot — movements called inversion and eversion. This motion is critical for walking on uneven surfaces, accommodating terrain changes, and absorbing rotational forces during gait.

The subtalar joint is a common site of arthritis, particularly post-traumatic arthritis following calcaneus (heel bone) fractures. It also becomes arthritic secondary to adult flatfoot (posterior tibial tendon dysfunction), inflammatory arthritis (rheumatoid, psoriatic), and primary osteoarthritis. When subtalar arthritis becomes severe and fails to respond to conservative treatment, surgical fusion is the standard of care.

Subtalar Arthritis: Causes and Presentation

Post-traumatic arthritis following calcaneus fractures is the most common indication for subtalar fusion. Calcaneus fractures are devastating injuries that frequently involve compression and disruption of the posterior facet — the primary articulating surface of the subtalar joint. Even after fractures are surgically reduced and fixed, articular damage often leads to progressive arthritis over the following years. Patients with a history of heel bone fractures who develop progressive hindfoot pain deserve subtalar joint evaluation.

Subtalar arthritis from adult flatfoot (PTTD) develops as the hindfoot collapses into a valgus (turned-out) position, creating abnormal loading on the subtalar joint surfaces. In advanced flatfoot deformity, the subtalar joint becomes fixed and arthritic, transitioning from a flexible to a rigid problem that requires fusion rather than joint-sparing procedures.

The characteristic presentation is hindfoot and lower ankle pain that worsens with walking on uneven ground, lateral ankle aching (due to impingement of the fibula against the calcaneus in valgus deformity), difficulty with stairs and inclines, and progressive loss of comfortable walking distance.

Diagnosis and Imaging

Isolated subtalar arthritis can be difficult to distinguish from ankle arthritis clinically, as both produce hindfoot pain. Diagnostic confirmation uses a combination of plain radiographs (weight-bearing lateral and Harris axial heel views), CT scanning (which provides the most detailed view of subtalar joint space and bone anatomy), and diagnostic injection — an anesthetic injected precisely into the subtalar joint under fluoroscopic or ultrasound guidance that temporarily eliminates subtalar-sourced pain and confirms the joint as the pain generator.

The Subtalar Fusion Procedure

Subtalar arthrodesis involves removing the remaining cartilage from the posterior facet joint surfaces of the talus and calcaneus, compressing the two bones together, and fixing them with one or two large-diameter cannulated screws (or, in some cases, staples or a plate). The goal is rigid internal fixation that eliminates all motion at the subtalar joint and promotes bone healing (fusion) across the joint space.

Bone graft — from the patient’s own bone (autograft, typically from the tibial crest) or from cadaveric bone (allograft) — may be used to fill gaps and enhance fusion. The procedure is typically performed through a small lateral incision and takes approximately 1.5–2 hours. It is done as an outpatient procedure or with a single-night hospital stay.

When hindfoot valgus deformity is present alongside subtalar arthritis, the procedure may be combined with a lateral column lengthening osteotomy or medial slide calcaneal osteotomy to correct alignment simultaneously. Triple arthrodesis — fusion of the subtalar, talonavicular, and calcaneocuboid joints — is performed when arthritis or deformity involves multiple hindfoot joints.

Recovery Timeline

Recovery from subtalar fusion requires a significant commitment to non-weight-bearing. A typical protocol includes:

• Weeks 1–6: Non-weight-bearing in a splint or cast; strict elevation; no pressure on the heel
• Weeks 6–12: Progressive weight-bearing in a cast or walking boot as X-rays confirm fusion progress
• Month 3–4: Transition to regular footwear with custom orthotics; formal physical therapy
• Month 4–6: Return to most daily activities; walking, driving, light work
• 6–12 months: Full activity return; resolution of swelling and adaptation to eliminated hindfoot motion

Outcomes and Functional Expectations

Subtalar fusion reliably eliminates subtalar-sourced pain and corrects hindfoot deformity. Fusion rates with modern techniques and fixation are 90–95%. Most patients experience significant pain reduction and meaningful improvement in walking ability. The trade-off — loss of subtalar motion — is generally well-tolerated because the remaining ankle and midfoot joints partially compensate. Walking on very uneven terrain (gravel, forest trails, rough ground) remains the activity most affected by subtalar fusion, though most patients adapt effectively.

Adjacent joint arthritis — particularly of the talonavicular joint — is a long-term concern after subtalar fusion, as eliminated subtalar motion transmits additional stress to neighboring joints. Appropriate alignment at the time of fusion and use of well-cushioned, accommodative footwear reduce this risk.

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Subtalar Fusion for Hindfoot Arthritis

Subtalar arthrodesis provides reliable pain relief for severe hindfoot arthritis while preserving ankle motion. Dr. Tom Biernacki performs subtalar fusion at Balance Foot & Ankle in Howell and Bloomfield Hills.

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Clinical References

1. Easley ME, et al. “Isolated subtalar arthrodesis.” J Bone Joint Surg Am. 2000;82(5):613-624.
2. Hungerer S, et al. “Subtalar joint fusion: results of a retrospective analysis.” Foot Ankle Int. 2013;34(11):1520-1527.
3. Chahal J, et al. “Outcomes of subtalar arthrodesis.” Foot Ankle Int. 2009;30(12):1101-1106.

Dr. Tom Biernacki, DPM

Affiliate Disclosure: This page contains affiliate links to products we recommend. If you purchase through these links, Balance Foot & Ankle may earn a small commission at no additional cost to you. We only recommend products we use with our patients.

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.