If the Ponseti Method is done correctly, most clubfeet are corrected within four to six casting sessions. The casts are changed weekly. Less than 5% of clubfeet may be very stiff and severe; they may need more casting, but Dr Ponseti wrote that even they should be corrected within eight to 10 casting sessions. For the most resistant cases, surgery is sometimes required, but it’s less radical than it would have been without the correct casting method.
Dr Ponseti’s method uses gentle manipulations while the baby is seated comfortably on the mother’s lap. Each time, the manipulation is done slightly differently to stretch another part of the foot and ankle. Then the plaster is applied. While one person holds the foot in the required position, an assistant rolls on the plaster cast. A lot of plaster is wrapped around the knee, which is bent at almost a 90 degree angle. The Ponseti method requires a full-leg cast up to the groin. The position of the knee and the full leg cast helps to immobilise the foot into the correct position.
The cast is then left on for five to seven days to hold the correction achieved and allow the baby’s ligaments and tendons to soften into the new position. The cast is removed and the next manipulation is done and the foot and leg re-casted until the displaced bones are brought into the correct alignment and the foot is correctly positioned.
The Ponseti Method of treatment should begin as early as possible, ideally when the baby is only around two weeks old. This is because the tissues forming the ligaments, joint capsules and tendons are still very elastic and stretch easily with each manipulation. It is also easier to cast a young baby than older child. However, Dr Ponseti and other doctors have successfully treated older babies and children, and avoided major surgery on the foot.
In many cases, before applying the last plaster cast, the Achilles tendon is cut in the doctor’s rooms. This is a simple procedure, which can be done with a local anaesthetic – it is a tiny cut at the back of the heel and no stitch required. By the time the cast is removed after three weeks, the tendon has regenerated to a proper length. The foot should appear overcorrected at first; this will change over time as the baby starts walking.
Following correction, the congenital condition that caused the clubfoot deformity in the first place tends to stay active and the foot can sometimes relapse. To prevent recurrence, when the last plaster cast is removed a foot abduction brace must be worn full-time, usually for three months and thereafter at night until four years of age. The clubfoot brace consists of a bar, with shoes attached to the ends of the bar. The gap between the shoes should be set to shoulder width, at 60-70º of external rotation and slightly angled up (toe higher than heel) at 10-15º of dorsiflexion to maintain the Achilles tendon length correction. In children with only one clubfoot, the shoe for the non-clubfoot is fixed on the bar at 30-40º of external rotation. During the daytime the children are barefoot or wear regular shoes. No stretching of the foot or physiotherapy is usually required, but some Ponseti practitioners give stretching exercises to be done at home.
The doctor can feel the position of the bones and the degree of correction, so X-rays of the feet are not required for young babies.
If the clubfoot brace wear is adhered to completely according to the recommended schedule, clinics report a 95% success rate. Some resistant foot may have recurrence, in which case further casting is done followed by a TATT or ATTT, a tibialis anterior tendon transfer. This is only done when the child is 3 to 4 years of age. The surgery consists of transferring the anterior tibial tendon to the third cuneiform, acting like an internal splint. This procedure does not have the negative after effects of full clubfoot surgery (Postero Remedial Release – PMR), such as scar tissue causing early onset arthritis.
Dr Ponseti’s opinion was that the poor results of cast and manipulative treatments of clubfeet by some doctors indicate that the attempts at correction have been inadequate because the techniques used are flawed. Without a thorough understanding of the anatomy and kinematics of the normal foot and of the deviation of the bones in the clubfoot, the deformity is difficult to correct. Poorly conducted manipulations and casting further compound the clubfoot deformity rather than correct it, making treatment difficult or impossible.
Surgeons with limited experience in the treatment of clubfoot should not attempt to correct the deformity. They may succeed in correcting mild clubfeet, but the severe cases require experienced hands.
Referral to a doctor with training and expertise in the Ponseti non-surgical correction of clubfoot should be sought before considering surgery.