Subtalar Fusion: A Surgeon’s Complete Guide to Technique, Recovery & Outcomes
Subtalar fusion (talocalcaneal arthrodesis) is a **highly effective surgical solution** for debilitating hindfoot pain caused by arthritis, deformity, or post-traumatic joint damage. When conservative treatments fail, fusion offers **long-term pain relief, stability, and improved function**—allowing patients to return to daily activities with confidence.
This comprehensive, surgeon-reviewed guide covers **anatomy, indications, surgical technique, hardware options, recovery timeline, complications, and patient outcomes**—complete with real clinical imaging and evidence-based protocols.
What Is the Subtalar Joint?
The subtalar joint lies **between the talus (ankle bone) and calcaneus (heel bone)**, forming the foundation of the hindfoot. Its primary function is to enable **inversion and eversion**—side-to-side motion critical for walking on uneven terrain, climbing stairs, and maintaining balance.
When this joint is damaged by arthritis, trauma, or deformity, pain, stiffness, and instability result—severely limiting mobility and quality of life.
Indications for Subtalar Fusion
Surgery is considered when non-operative measures (orthotics, injections, physical therapy) fail. Common indications include:
- Post-traumatic arthritis (after calcaneal or talus fractures)
- Rheumatoid arthritis or other inflammatory arthropathies
- Rigid hindfoot deformities (e.g., severe flatfoot, clubfoot)
- Failed previous surgery (e.g., coalition resection)
- Chronic instability unresponsive to bracing
Surgical Technique: Step-by-Step
Subtalar fusion is typically performed under general or regional anesthesia. The patient is positioned **supine or lateral**, depending on surgeon preference and deformity correction needs.
1. Approach
A **6–8 cm incision** is made along the **lateral aspect of the hindfoot**, centered over the subtalar joint. Care is taken to protect the sural nerve and peroneal tendons.
2. Joint Preparation
All articular cartilage is meticulously removed using rongeurs and burrs until **bleeding subchondral bone** is exposed. The joint surfaces are then contoured to achieve **optimal alignment and maximum surface contact**.
3. Bone Grafting
Autograft (from the calcaneus, tibia, or iliac crest) or allograft is packed into the fusion site to stimulate healing—especially in cases of bone loss or deformity correction.
4. Fixation
Hardware is placed under fluoroscopic guidance to ensure correct trajectory and depth. Common options include:
| Fixation Method | Advantages | Disadvantages |
|---|---|---|
| Two parallel screws | Simple, strong compression, low profile | Limited rotational control |
| Plate + screw | Superior stability in osteoporotic bone or complex deformities | Higher profile, risk of hardware irritation |
| Headless compression screws | Minimal soft tissue irritation, excellent compression | Higher cost |
5. Wound Closure
Deep layers are closed with absorbable sutures (e.g., Vicryl). The skin is closed with non-absorbable sutures or staples. A **well-padded posterior splint** is applied with the ankle in neutral position.
Treatment: Real Clinical Imaging
Postoperative imaging confirms hardware position and alignment.
Figure 1: X-ray lateral view of the ankle and axial view of the calcaneus showing subtalar fusion by two screws. Note the complete removal of joint space and stable hardware placement across the talocalcaneal joint.
Recovery Timeline & Rehabilitation
Recovery is staged to protect the fusion while minimizing complications.
| Timeframe | Protocol |
|---|---|
| 0–2 Weeks | Non-weight-bearing, elevation, splint immobilization. Suture removal at 14 days. |
| 2–6 Weeks | Transition to short-leg cast. Continue non-weight-bearing. |
| 6–12 Weeks | Gradual weight-bearing as tolerated. Serial X-rays to confirm fusion. |
| 12+ Weeks | Full weight-bearing in supportive footwear. Physical therapy for gait training. |
Risks and Complications
While generally safe, potential complications include:
- Nonunion (5–10%): Failure of bones to fuse
- Malunion: Healing in poor alignment
- Infection (1–3%): Superficial or deep
- Hardware irritation: May require removal
- Adjacent joint arthritis: Due to altered biomechanics
- CRPS (Chronic Regional Pain Syndrome)
Outcomes: What to Expect
Studies show **85–95% success rates** with significant pain reduction and functional improvement:
- 90% of patients report **excellent pain relief
- 80% return to **daily activities and light sports
- Most adapt well to **reduced hindfoot motion
While inversion/eversion is lost, the trade-off for **stability and pain freedom** is overwhelmingly positive.
Frequently Asked Questions (FAQs)
A: Radiographic union typically occurs by **10–12 weeks**, but full remodeling may take 6–12 months.
A: Only if they cause pain or irritation—usually after 12–18 months. Most patients keep them indefinitely.
A: For right foot: Not until full weight-bearing (12+ weeks). For left foot in automatic car: May resume at 6–8 weeks if comfortable.
A: Rigid-soled, supportive shoes (e.g., rocker-bottom) are ideal. Avoid flexible soles or high heels.
A: Yes—in select cases with minimal deformity. Open technique remains gold standard for most patients.
Conclusion
Subtalar fusion is a **reliable, durable solution** for end-stage hindfoot arthritis and deformity. With meticulous surgical technique, patient compliance, and structured rehabilitation, most individuals achieve **dramatic pain relief and restored function**.
At BoneFractures.org, we believe informed patients make better decisions. Always consult a fellowship-trained foot and ankle orthopedic surgeon to determine if fusion is right for you.
References
- American Orthopaedic Foot & Ankle Society (AOFAS). Subtalar Fusion. FootCareMD. 2025.
- Royal Orthopaedic Hospital. Subtalar Joint Fusion Patient Guide. Birmingham, UK. 2025.
- Stern PJ, et al. Subtalar Arthrodesis: Indications, Techniques, and Outcomes. J Am Acad Orthop Surg. 2021;29(12):e521-e530.
- Kuo RS, et al. Outcomes of Subtalar Fusion for Post-Traumatic Arthritis. Foot Ankle Int. 2020;41(5):521–528.
- Greg Sterling, MD. Subtalar Joint Fusion Protocol. Brisbane Orthopaedic Centre. 2025.
— Written by Dr. Mohamed Attia, Orthopedic Surgeon
Published on BoneFractures.org – Evidence-based fracture and joint care for patients and professionals.