Clubfoot

Genetic mapping and the development of models of the disease have improved understanding of developmental processes. Its inheritance pattern is explained as a heterogenous disorder using a polygenic threshold model. The PITX1-TBX4 transcriptional pathway has become key to the study of clubfoot. PITX1 and TBX4 are uniquely expressed in the hind limb.^[28]

Diagnosis

Clubfoot is diagnosed through physical examination. Typically, babies are examined from head-to-toe shortly after they are born. There are four components of the clubfoot deformity:

1		Cavus : the foot has a high arch, or a caved appearance.
2		Adductus : the forefoot curves inwards toward the big toe.
3		Varus: the heel is inverted, or turned in, forcing one to walk on the outside of the foot. This is a natural motion but in clubfoot the foot is fixed in this position.
4		Equinus: the foot is pointed downward, forcing one to walk on tiptoe. This motion occurs naturally, but in clubfoot the foot is fixed in this position. This is because the Achilles tendon is tight and pulls the foot downwards.

Factors used to assess severity include the stiffness of the deformity (how much it can be corrected by manually manipulating the foot), the presence of skin creases at the arch and heel, and poor muscle consistency.

Sometimes, it is possible to detect clubfoot before birth using ultrasound. Prenatal diagnosis by ultrasound can allow parents to learn more about this condition and plan ahead for treatment after their baby is born.^[29]

More testing and imaging is typically not needed, unless there is concern for other associated conditions.

Treatment

Treatment is usually with some combination of the

The Ponseti method corrects clubfoot over the course of several stages.

• Serial casting: First, the foot is manually manipulated into an improved position and held in place with a long leg cast which extends from the toes up to the thigh. After a week this cast is removed, the foot is re-manipulated, and placed into a new cast. This process repeats and the foot is gradually reshaped over the course of 4-6 serial casts, although some feet may require additional casts.
  • The goal of the initial cast is to align the forefoot with the hindfoot. Ponseti describes the forefoot as
    supinating the forefoot and elevating the first metatarsal
    improves this alignment.
  • Subsequent casts are applied after stretching the foot with a focus on
    abducting the forefoot with lateral pressure at the talus, to bring the navicular laterally and improve the alignment of the talonavicular joint. In contrast to the Kite method of casting, it is important to avoid constraining the calcaneocuboid joint. With each additional cast, the abduction is increased and this moves the hindfoot from varus into valgus
    . It is important to leave the ankle in equinus until the forefoot and hindfoot are corrected.
  • The final stage of casting is to correct the equinus. After fully abducting the forefoot with spontaneous correction of the hindfoot, an attempt is made to bring the ankle up and into
    dorsiflexion
    . The foot must have the ability to dorsiflex to at least 10 degrees past 0 (neutral, or L position), although 15 degrees or more is better and preferred. If the foot can not dorsiflex enough, the brace will not work/be tolerated. If it is determined the foot can not dorsiflex at least 10 degrees, the Achilles Tenotomy surgical procedure is performed.
• Achilles tendon release: At the end of the serial casting, most children have corrected cavus, adductus and varus deformities, but continue to have equinus deformity. To correct this, a procedure called an Achilles tendon release (commonly called Achilles tenotomy) is performed. Before the procedure, many centers place the child under sedation or monitored anesthesia care, although Ponseti recommended using local anesthetic alone. Next, the area around the heel is cleansed and numbed, and a small scalpel is used to cut the Achilles tendon. The incision is small so there is minimal bleeding and no need for stitches. The skin is covered with a small dressing, and the foot is placed into a final long leg cast in a fully corrected position. This cast is typically left in place for three weeks. During this time, the Achilles tendon will regrow in a lengthened position.
• Bracing: After successful correction is achieved through serial casting and Achilles tenotomy, the foot must be kept in a brace to prevent it from returning to the deformed position over the first few years of a child's life. The brace is made up of two shoes or boots that are connected to each other by a bar that is bent under the shoes at 10–15 degrees, or curved to create 10–15 degrees dorsiflexion. This device is also called a foot abduction brace (FAB) or more generally boots and bar (BnB). At first, the brace is worn full-time (23 hours per day) on both feet, regardless of whether the clubfoot affects one or two feet. After 3 months of 23/7 wear, the brace is worn less frequently by gradually reducing hours a couple at a time, every couple months so that hours are down to 12–14 per day at or around a year old. From this point on until at least 4–5 years, or even longer (6–9 years if needed), the brace is worn mostly while sleeping at night and during naps (12–14 hours per day). Bracing is essential in preventing recurrence of the deformity and is a major determinant of a child's long-term outcome.^[34]

The Ponseti method is highly effective with short-term success rates of 90%.^[34] However, anywhere from 14% to 41% of children experience a recurrence of the deformity, with as many as 56% requiring an additional surgery beyond the 10 year mark.^[35][36][37] The most common reason for this is inadequate adherence to bracing, such as not wearing the brace properly, not keeping it on for the recommended length of time, or not using it every day. Children who do not follow proper bracing protocol have up to seven times higher recurrence rates than those who follow bracing protocol, as the muscles around the foot can pull it back into the abnormal position.^[35] Low parental education level and failure to understand the importance of bracing is a major contributor to non-adherence.^[34] Relapses are managed by repeating the casting process. Relapsed feet may also require additional, more extensive surgeries and have a reduced chance of achieving subsequent correction.^[34] Furthermore, research has revealed the possibility of overcorrection after use of the Ponseti method.^[38][37]

Another reason for recurrence is a congenital muscle imbalance between the muscles that invert the ankle (

Compared to the Ponseti method which uses rigid casts and braces, the French method uses tape which allows for some motion in the feet. Despite its goal to avoid surgery, the success rate varies and surgery may still be necessary. The Ponseti method is generally preferred over the French method.[3]

Surgery

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If non-operative treatments are unsuccessful or achieve incomplete correction of the deformity, surgery is sometimes needed.^[39] Surgery was more common prior to the widespread acceptance of the Ponseti method. The extent of surgery depends on the severity of the deformity. Usually, surgery is done at 9 to 12 months of age and the goal is to correct all the components of the clubfoot deformity at the time of surgery.

For feet with the typical components of deformity (cavus, forefoot adductus, hindfoot varus, and ankle equinus), the typical procedure is a Posteromedial Release (PMR) surgery. This is done through an incision across the medial side of the foot and ankle, that extends posteriorly, and sometimes around to the lateral side of the foot. In this procedure, it is typically necessary to release (cut) or lengthen the plantar fascia, several tendons, and joint capsules/ligaments. Typically, the important structures are exposed and then sequentially released until the foot can be brought to an appropriate plantigrade position. Specifically, it is important to bring the ankle to neutral, the heel into neutral, the midfoot aligned with the hindfoot (navicula aligned with the talus, and the cuboid aligned with the calcaneus). Once these joints can be aligned, thin wires are usually placed across these joints to hold them in the corrected position. These wires are temporary and left out through the skin for removal after 3–4 weeks. Once the joints are aligned, tendons (typically the Achilles, posterior tibialis, and flexor halluces longus) are repaired at an appropriate length. The incision (or incisions) are closed with dissolvable sutures. The foot is then casted in the corrected position for 6–8 weeks. It is common to do a cast change with anesthesia after 3–4 weeks, so that pins can be removed and a mold can be made to fabricate a custom AFO brace. The new cast is left in place until the AFO is available. When the cast is removed, the AFO is worn to prevent the foot from returning to the old position.^[29]

For feet with partial correction of deformity with non-operative treatment, surgery may be less extensive and may involve only the posterior part of the foot and ankle. This might be called a posterior release. This is done through a smaller incision and may involve releasing only the posterior capsule of the ankle and subtalar joints, along with lengthening the Achilles tendon.

Surgery leaves residual scar tissue and typically there is more stiffness and weakness than with nonsurgical treatment. As the foot grows, there is potential for asymmetric growth that can result in recurrence of foot deformity that can affect the forefoot, midfoot, or hindfoot. Many patients do fine, but some require orthotics or additional surgeries. Long-term studies of adults with post-surgical clubfeet, especially those needing multiple surgeries, show that they may not fare as well in the long term.^[40] Some people may require additional surgeries as they age, though there is some dispute as to the effectiveness of such surgeries, in light of the prevalence of scar tissue present from earlier surgeries.

Developing world

Despite effective treatments, children in LMICs face many barriers such as limited access to equipment (specifically casting materials and abduction braces), shortages of healthcare professionals, and low education levels and socioeconomic status amongst caregivers and families.^[41] These factors make it difficult to detect and diagnose children with clubfoot, connect them to care, and train their caregivers to follow the proper treatment and return for follow-up visits. It is estimated that only 15% of those diagnosed with clubfoot receive treatment.^[12]

In an effort to reduce the burden of clubfoot in LMICs, there have been initiatives to improve early diagnosis, organize high-volume Ponseti casting centers, utilize mid-level practitioners and non-physician health workers, engage families in care, and provide local follow-up in the person's community.^[42]

Cultural references

• Hippolyte Tautain, the stableman at the Lion D'Or public house in the 1856 novel Madame Bovary by Gustave Flaubert, has clubfoot. Charles Bovary tries to correct it, but the procedure is unsuccessful, and Tautain must have an amputation.
• Philip Carey, the main character of the 1915 novel Of Human Bondage by W. Somerset Maugham, has clubfoot. It is a central theme of the work.
• Velma, a character in the 1941 film High Sierra, has clubfoot. It is successfully treated with surgery.
• Gimpy, a coworker of the main character in the 1959 science fiction short story "Flowers for Algernon" by Daniel Keyes, has clubfoot.
• Kashiwagi, a character in the 1956 novel The Temple of the Golden Pavilion by Yukio Mishima, has clubfoot. It parallels the main character, Mizoguchi, who has a stutter.
• Johnson, a character in the 1965 short story "The Lame Shall Enter First" by Flannery O'Connor, has clubfoot. It is a major symbol in the story.
• The main character of the 1974 science fiction novel The Bladerunner by Alan E. Nourse has clubfoot.
• The main character of the 1985 novel
  Perfume: The Story of a Murderer by Patrick Süskind
  , has clubfoot. It causes a limp.
• Senji, a character in the 1987 to 1991 fantasy book series
  The Mallorean by David Eddings
  , has clubfoot.
• Kwai Geuk-Chat, a character in the 1993 film Once Upon a Time in China III, which is part of the 1991 to 1997 Once Upon a Time in China series, has clubfoot. He is nicknamed "Clubfoot Seven Chiu-Tsat" – "Clubfoot" because of his foot, and "Seven Chiu-Tsat" because he is the seventh member of the character Chiu Tin-bak's apprentices, disciples, and henchmen.
• Mordred, King of Dumonia, a character in the 1995 to 1997 historical fantasy book series The Warlord Chronicles by Bernard Cornwell, has clubfoot. It is often used as a symbol for his weakness as a ruler.
• Charlie Wilcox, the main character of the 2000 children's book of the same name by Sharon McKay, has clubfoot.
• Vulcan the blacksmith, a character in the 2001 novel The Secrets of Vesuvius, which is part of the 2001 to 2009 historical fiction series The Roman Mysteries by Caroline Lawrence, has clubfoot.
• Ada, the main character of the 2016 children's book The War That Saved My Life by Kimberly Brubaker Bradley, has clubfoot. Her mother emotionally and physically abuses her because of it.
• Larys Strong, called "the Clubfoot", first appears in George R. R. Martin's 2013 fantasy novella The Princess and the Queen, part of A Song of Ice and Fire. He is the secretive and sly master of whisperers for King Viserys I Targaryen and his successor Aegon II Targaryen. Larys's character was later expanded on in the novel Fire & Blood (2018) and its television adaptation House of the Dragon (2022).

References