Technique of percutaneous temotomy for CTEv in prone position

Indications for Tenotomy

Cases of CTEV on treatment with serial plasters by Ponseti method where forefoot is corrected but there is inability to get the ankle dorsiflexion beyond 20º.

Prerequisites

1. Pirani midfoot score 0
2. Forefoot abduction of approximately 60º should be achieved
3. Lateral border should be straight
4. Heel should be neutral or slight valgus

This abduction allows the foot to be safely dorsiflexed without crushing the talus between the calcaneus and tibia If the adequacy of abduction is uncertain, apply another cast or two to be certain. Abduction of approximately 60 degree in relation­ship to the frontal plane of the tibia is possible. Neutral or slight valgus of os calcis is present. This is determined by palpating the posterior os calcis.

Preparing the family-

Parents should be properly informed about the nature of the procedure proper consent should be taken. Post operative elevation, possibility of red discolouration due to blood ooze should also be explained

Anasthesia-

Tendoachilis tenotomy is done under local anesthesia. Before taking the patient on table lignocaine sensitivity test must be done.

Position-

Prone position is given to patient with proper padding for the trunk. An OT assistant

Preparation –

Procedure should be done in operation theatre to maintain the sterility and prepared for any complication though very rare.

Limbs are prepared with antiseptic solution distal to knee joint. Draping is done to isolate the field but care should be taken not to suffocate the child.

Surgeon should always wear the operating gown and sterile gloves.

Inj lignocaine 4%

without adrenaline is infilterated near and just above the tendoachilis insertion

Procedure–

Assistant dorsiflexes the ankle making the tendon tight and prominent keeping knee in extension. Tendon should be palpated at the insertion. 15 no blade (always with the handle for better control) is inserted with the single prick like incision (3-4 mm) just above the tendoachilis insertion medial to lateral side of the tendon with the bevel facing laterallt. The blade is now turned by 90 degrees to remain horizontal on anterior surface of the tendon. Tenotomy is done from inside out fashion from anterior to posterior surface of the tendon. Care should be taken not to damage the calcaneal cartilage. As assistant continues the dorsiflexion sudden “pop” is felt with achieving the full dorsiflexion. Dorsiflexion should be checked both in knee flexed and extended. There is no need to take sutures. Small dressing is applied and child should immediately handed over to mother for feeding.

After 10 minutes once the bleeding is controlled and the child is relaxed an above knee pop is applied with knee in 90 flexion and feet externally rotated 60 and 20 dorsiflexion

Advantages of the prone position–

1. It is very easy to hold the child in the prone position.
2. Child is very comfortable in this position and does not kick while doing the procedure making the surgeon comfortable and in better control to carry out the procedure.
3. Tendoachilis is posterior structure and prominent in this position and therefore only tight tendon fibres are cut and avoid damage to peritendinous soft tissues.
4. Chances of damaging the neurovascular structures are very less.