Congenital clubfoot
Congenital clubfoot is the most common congenital deformity of the foot (Figure 19-5-16), with a prevalence of 1 per 1,000 men and a male to female ratio of approximately 5:1. Horseshoe clubfoot can exist alone or be accompanied by other deformities, such as developmental hip dislocation, acetabular dysplasia, multiple joint contractures, syndactyly, polydactyly, etc.
Etiology
The etiology of congenital clubfoot is not well understood and is related to the following factors.
1, genetic factors
Families with clubfoot, the incidence of its offspring is 25-30 times the normal population, different races, the incidence is also different, the national 0, 39 per 1,000, Polynesia 6, 8 per 1,000. It is suggested that the development of congenital clubfoot is related to genetic factors. Some scholars believe that the mode of inheritance is based on polygenic inheritance, multifactorial synergistic effects.
2.Neuromuscular lesions
It was found that the type I muscle fibers in the posterior medial muscles of the foot and calf increased and clustered, and the neurophysiological study found that most of the affected children had spinal cord and peripheral nerve damage, and some cases combined with occult sacral spina bifida, and the calf muscles were obviously atrophied, and the improvement was not obvious after treatment.
3.Gene mutation
Recent studies have found that the transcription factor Hox gene is related to clubfoot, which regulates the formation of limbs during embryonic development, so the Hox gene may cause congenital clubfoot.
4. Abnormal skeletal development and fibrous tissue contracture during embryonic development
Some authors have shown that clubfoot has defects in cartilage development and contracture of soft tissues.
5. Other abnormalities such as vascularity and amniocentesis in early pregnancy may also lead to clubfoot.
Pathology
The pathology of clubfoot is a typical dysplasia involving soft and skeletal tissues. The soft tissues show varying degrees of contracture of the metatarsal tendon membrane, medial and posterior tendons, fascia, ligaments and joint capsule. The anterior tibialis, posterior tibialis, triceps calf, [long flexor, and long toe flexor muscles were contracted, while the peroneal muscles were flaccid. There was also contracture of the anterior tibial tendon, [long extensor, and long toe extensor; there was also contracture of the deltoid ligament, heel navicular ligament, spring ligament, posterior heel fibular ligament, and posterior talofibular ligament. The contracture of the posterior joint capsule and the talocrural joint capsule of the ankle and subtalar joint was more pronounced. Contracture of the plantar tendon membrane and the short toe flexors causes high arches and drooping of the 1st toe bone.
Pathologic changes of the bones and joints, with the talus being most involved, manifest as decreased volume, short talar neck, severe plantar flexion, and medial and metatarsal axis deviation; the navicular bone is displaced medially and forms a joint with the medial side of the talar head, the dice bone is delayed in development and is correspondingly displaced medially, and the intertarsal alignment is abnormal. These deformities result in extensive limb dysplasia, shortened feet, thinning calves, and unequal limbs, and correlate with the severity of clubfoot.
Microscopically, the ligaments of newborns contain many collagen fibers and cells, and bundles of collagen fibers form corrugated folds, which are easily pulled without damage, and after a few days, the folds reappear, which is the feasible principle for the correction of clubfoot by manipulation.
Clinical manifestations
After birth, one foot or both feet show horseshoe inversion changes. The forefoot shows inversion, internal rotation, medial displacement of the midfoot, high arch deformity, hindfoot inversion and horseshoe changes, all combined with tibial internal rotation, the diagnosis is not difficult, should pay attention to the presence of musculoskeletal system diseases and neural tube closure insufficiency.
Classification
Generally, there are two types of deformities: rigid and flaccid.
1.Stiff type: The deformity is serious and fixed, a deep transverse skin fold can be seen on the metatarsal surface, the heel bone is small, the heel bone is hidden inside due to sagging, the Achilles tendon is thin and tight, the skin is also relatively taut, showing obvious horseshoe, inversion, inversion deformity, mostly bilateral.
2, flaccid: deformity is lighter, the foot is small, the skin and tendon are not tight, can be corrected by manipulation.
[Imaging].
Since most of the treatment of clubfoot is carried out at an early stage, especially with the popularization of the Ponseti method, X-ray examination has rarely been applied, but as the age of the child increases, X-ray examination becomes valuable. In the orthopantomograph, the angle of intersection of the long axis of the heel and talus is reduced or the heel talus overlaps (the normal angle of intersection of the long axis of the heel and talus is 30° to 55°); in the lateral view, the angle of the heel and talus is reduced (the normal angle is 25° to 30°) or even disappears, the heel talus becomes parallel, and the navicular bone is displaced dorsally.
Diagnosis and differential diagnosis
The diagnosis of clubfoot is not difficult, there is a horseshoe, inversion, inversion deformity of one or both feet after birth, but it needs to be differentiated from other clubfoot.
1, neonatal foot inversion: This is similar to the appearance of congenital horseshoe foot, mostly on one side, the foot is horseshoe inversion, but the medial side is not tight, the foot can be dorsally extended to touch the tibial surface, after 1 to 2 months of fixed bandage completely back to normal.
2. Occult spina bifida:
About 30% to 40% of cases spinal x-ray confirmed spina bifida, this type of horseshoe foot is mostly unilateral, the front half of the foot medially not only can be abducted, according to the lateral foot numb area, but the infant is not easy to check, spina bifida is often accompanied by symptoms of incontinence.
3, gray myelitis sequelae horseshoe foot: this type of horseshoe foot onset age, in more than 4 years old, there is a history of fever, unilateral more common, with peroneal long and short muscle paralysis, no fixed deformity, other muscle paralysis is obvious, urinary and fecal incontinence is not affected.
4, cerebral palsy horseshoe foot: horseshoe foot is found after birth, disappears during sleep, appears as soon as stimulated, deformity is mainly horseshoe.
5, polyarticular contracture: horseshoe foot is bilateral with polyarticular deformity, lower limb muscle atrophy and stiffness, accompanied by other deformities, the diagnosis is not easily confused.
Treatment】
The purpose of treatment is to correct the deformity, retain its mobility and muscle strength, restore the normal weight-bearing area of the foot, so that the child can walk normally with weight, improve the appearance, avoid and reduce the complexity of surgery, but congenital clubfoot is not possible to completely correct, compared with the normal foot, may remain a small amount of stiffness, shortening or deformity.
I. Non-surgical treatment
The Ponseti treatment method has now become the standard of care in many countries. This method begins 7 to 10 days after birth with gentle, stable and strong manipulation, continuous abduction in a certain sequence on the forefoot in the rotated posterior position and a series of tubular cast fixation to correct this type of deformity (Figure 19-5-17). This method not only retracts the medial and metatarsal contracted soft tissues, but also resets the medially dislocated navicular and dice bones, continuously abducts the forefoot in the posterior rotated position with the thumb on top of the talar head, abducts, dorsiflexes, and extends the heel bone in the subtalar joint, and corrects the inversion and adduction deformity of the heel bone. Therefore, the Ponseti treatment can simultaneously correct the pronation of the forefoot, the high arch of the midfoot and the pronation of the hindfoot, and then correct the horseshoe deformity of the foot by subcutaneous Achilles tendon severance. It is emphasized to keep the foot in abduction dorsiflexion position with a brace for 24 hours/day for 3 months, and then the wearing time is reduced to 12 hours at night and 2-4 hours during the day, which is maintained until the child is 3 to 4 years old.
II. Surgical treatment
Non-surgical treatment fails or fails to completely correct the deformity and cases with delayed treatment need surgical treatment.
1.Soft tissue release surgery: The most commonly used surgery at home and abroad is Turco and Mckay surgery, which corrects the medial displacement of the navicular bone and the inversion, internal rotation and plantar flexion deformity of the heel bone; Mckay emphasizes the correction of the inversion, internal rotation and plantar flexion deformity of the heel bone through extensive release of the internal, posterior and lateral parts of the foot. Some domestic scholars have used muscle balance surgery to achieve good results.
2.Bone surgery: for recurrence of clubfoot after surgery or those who are too old for soft tissue surgery, triple joint fixation is performed after 10 years of age. Postoperative complications include recurrence, joint stiffness, weakness and excessive orthosis.