Percutaneous Achilles Tenotomy for CTEV

Indications

1. Cavus, Adductus and Varus are fully corrected but ankle dorsiflexion remains <10 degrees above neutral
2. Adequate abduction:
   • Best sign: Ability to palpate anterior process of the calcaneus as it abducts out from beneath the talus
   • Abduction of approximately 60 degrees
   • Neutral or slight valgus of os calcis

Technique

1. Anesthesia: General anesthesia or Local anesthesia

2. Skin preparation: Prepare the foot thoroughly from midcalf to midfoot with antispetic

3. Position: Assistant holds the foot in maximum dorsiflexion with knee extended

4. Site of tenotomy: about 1.5-2 cm above the calcaneus

5. Equipment for tenotomy:

• Blade: Size #11 or #15 or other smaller blades OR
• Needle: 18 G (<6 months age); 16 G (>6 months age)

6. Tenotomy:

• Blade tenotomy:
  • Insert the tip of the scalpel blade from the medial side, directed immediately anterior to the taut tendon keeping the flat part of blade parallel to the tendon
  • The blade is then rotated, so that its sharp edge is directed posteriorly towards the tendon. The blade is then moved a little posteriorly.
• Needle tenotomy:
  • Cut the tendon with the tip of needle from medial to lateral (grating sensation is felt as the fibers are cut)
• Signs of completed tenotomy:
  • A “pop” is felt as the sharp edge releases the tendon
  • Additional 15 to 20 degrees of dorsiflexion is typically gained after the tenotomy
  • Negative Thompson test

7. Post-tenotomy cast:

• Type: Above knee cast
• Position: 60-70 degrees abduction of foot and 15 degrees dorsiflexion
• Duration: 3 weeks

References:

1. Clubfoot: Ponseti Management (3rd Edition)
2. Percutaneous Achilles Tenotomy with a Large Gauge Needle in Ponseti Management of CTEV: A Modified Technique