A 6-month-old male infant with a history of bilateral CTEV treated with the Ponseti method presents with his mother for follow-up. Serial casting and percutaneous Achilles tenotomy were completed 2 months ago, and the foot deformities have been corrected. The mother reports that she has been inconsistently applying the Denis Browne splint (FAO) — using it only 12–14 hours per day instead of the prescribed 23 hours. On examination, mild inversion and plantarflexion are beginning to recur. What is the most likely explanation for this clinical finding, and what is the recommended management?

Explanation

## Relapse and Recurrence in CTEV — Role of Bracing Compliance ### Definition and Epidemiology **Key Point:** Relapse (recurrence of deformity after initial correction) occurs in 15–20% of cases treated with the Ponseti method, and **inadequate bracing compliance is the most common cause**. The critical maintenance phase is the first 4–5 years of life. ### Mechanism of Relapse 1. **Intrinsic muscle imbalance** — the tibialis posterior and intrinsic foot muscles remain relatively strong compared to dorsiflexors and evertors 2. **Growth and remodeling** — without sustained external correction via bracing, the foot gradually drifts back toward the original deformity 3. **Inadequate bracing duration** — using the FAO (Denis Browne splint) for <20 hours/day significantly increases relapse risk ### Relapse vs. Resistant CTEV | Feature | Relapse | Resistant/Rigid CTEV | |---------|---------|----------------------| | **Onset** | After initial correction | Fails to correct with serial casting | | **Cause** | Inadequate bracing, muscle imbalance | Severe initial deformity, neurogenic involvement | | **Response to re-casting** | Excellent (>90% success) | Poor; may require surgery | | **Bracing requirement** | 23 hrs/day for 3–5 years | Longer or surgery needed | ### Management of Relapse **High-Yield:** Early detection and prompt re-intervention with **serial casting (2–4 weeks) followed by strict bracing compliance** can correct relapse in >90% of cases. Surgery is NOT indicated for relapse if caught early. ### Bracing Protocol (Critical) - **Denis Browne splint (FAO)** or similar foot abduction orthosis - **23 hours/day** for the first 3 months after tenotomy - **Nighttime use only** (8–10 hours) from 3 months to 3–4 years of age - **Compliance monitoring** at each clinic visit **Clinical Pearl:** Mothers who understand the "relapse risk" and the critical importance of bracing have significantly better outcomes. Structured follow-up and education are essential. ### Why Early Re-intervention Works - The foot tissues remain relatively pliable in infancy - Re-casting is less traumatic than primary surgery - Reinforced bracing prevents further relapse **Mnemonic: BRACE** — **B**racing compliance essential, **R**elapse risk 15–20%, **A**void surgery if caught early, **C**asting re-applied for 2–4 weeks, **E**arly detection improves outcomes