A 3-month-old girl with bilateral CTEV has completed 6 weeks of Ponseti casting. On examination, the feet now show 45° of external rotation and neutral dorsiflexion. However, the right foot still has 15° of residual equinus that cannot be passively corrected. The parents ask about the next step. What is the most appropriate management at this stage?

Explanation

## Residual Equinus in CTEV: Role of Percutaneous Tenotomy **Key Point:** When residual equinus (typically >10–15°) persists despite adequate Ponseti casting, percutaneous Achilles tenotomy is the standard next step. This allows final dorsiflexion without forcing the foot, which risks rocker-bottom deformity. ### Why Tenotomy Is Necessary **High-Yield:** The Achilles tendon is the primary limiting structure in equinus deformity. Once the foot is fully abducted and the midfoot deformity is corrected, residual equinus is almost always due to Achilles tightness. Tenotomy releases this tension, allowing passive dorsiflexion to neutral or slight dorsiflexion. ### Ponseti Protocol for Residual Equinus | Step | Timing | Action | |------|--------|--------| | **1. Abduction casting** | Weeks 1–6 | Correct varus and cavus | | **2. Assess equinus** | Week 6 | If equinus ≤10°, proceed to bracing; if >10°, plan tenotomy | | **3. Percutaneous tenotomy** | Week 6–8 | Needle tenotomy under local anesthesia (office procedure) | | **4. Final dorsiflexion cast** | Post-tenotomy | 3-week cast to hold foot in neutral/slight dorsiflexion | | **5. Bracing** | After final cast | Denis Browne splint or AFO until age 4–5 years | **Clinical Pearl:** Percutaneous tenotomy is a minor, office-based procedure with minimal morbidity. It is far less invasive than open surgical release and is the standard of care in the Ponseti method. ### Why the Other Options Are Suboptimal - **Continued casting without tenotomy** will not correct Achilles-limited equinus; forcing dorsiflexion risks creating a rocker-bottom (convex) foot. - **Open surgical release** is reserved for neglected cases or late presentations; it is not indicated after successful Ponseti casting. - **Immediate bracing** without addressing residual equinus will allow the deformity to recur; the foot must be fully corrected before bracing begins. **Mnemonic:** **TENOTOMY TIMING = Tendon tightness >10–15°, Early intervention (week 6–8), Needle-based (percutaneous), Office procedure, Tenotomy, Followed by final cast, Then bracing** [cite:Campbell's Operative Orthopaedics 13e Ch 32; Ponseti IM. Congenital Clubfoot: Fundamentals of Treatment. 2nd ed. Oxford University Press; 2008]