Congenital clubfoot is a common congenital deformity of the foot, with an incidence of about 0.1%, more males than females, 2:1 male:female, and less unilateral than bilateral incidence.
I. Etiology
The etiology is still unclear, and there are various theories. There are genetic theory, neuromuscular theory, foot soft tissue contracture theory, vascular anomaly theory, regional growth disorder and intrauterine developmental block theory, etc.
Second, pathology
The deformities of clubfoot include: forefoot inversion, heel inversion, and ankle drop. Skeletal changes: early stage is limited to the talus, followed by changes in the heel bone, navicular bone and dice bone. Joint changes: In severe cases, the talus head and navicular bone are dislocated accordingly. Muscle and tendon changes: all groups of calf muscles are poorly developed and in a state of atrophy, with contractures on the inner, posterior and metatarsal sides of the foot. Lin Xiaoyong, Department of Microtrauma, Zhongshan Hospital of Traditional Chinese Medicine
III. Clinical manifestations
After birth and discovery of unipedal or bipedal deformity. It manifests as severe plantar flexion of the affected foot, forefoot inversion and plantar inward. From the treatment effect, congenital clubfoot can be divided into floppy type and stiff type. The floppy deformity is mild and easy to correct by manipulation. Stiff deformities are more severe and difficult to correct by manipulation. In untreated children, the deformity gradually worsens, with abnormal gait when walking and callus on the lateral edge of the foot. The calf muscle on the affected side is significantly atrophied compared to the healthy side.
X-ray and other examinations
For newborns, clinical examination can confirm the diagnosis of clubfoot. x-ray examination can understand the relationship between the bones of the deformity, which can help to formulate the treatment plan and evaluate the effect after treatment, as well as to follow up the patient to see if there is any recurrence of the deformity. X-rays are of little significance in newborns and young patients whose epiphyses have not yet appeared, and require anteroposterior views in weight bearing and lateral views in maximum flexion and abduction.
The orthopantomograph of a normal foot shows that the talus is in a straight line through the navicular bone, the cuneus and the first metatarsal, and the heel is in a straight line through the dice bone and the fourth metatarsal, with the intersection angle of the two lines being 300~350; the lateral film shows that the intersection angle between the talus and the axis of the heel is 300. The orthopantomograph and lateral position of the clubfoot are 100~150 and 50~100, respectively.
Ultrasonography can detect horseshoe foot deformity during maternal pregnancy, and, the positive rate is high. Other examinations such as arthrography, CT and MRI are useful for the study of clubfoot, but are not done as routine examinations.
V. Diagnosis and differential diagnosis
The diagnosis of congenital clubfoot can be determined based on clinical manifestations. However, it needs to be differentiated from clubfoot caused by cerebral palsy, spinal cord tethering syndrome, poliomyelitis sequelae, and multiple joint contractures.
VI. Treatment
In principle, the earlier treatment is started, the better.
(A) Conservative treatment
The cure rate for congenital clubfoot can reach 90%, with weekly correction and plaster replacement (polyester or glass fiber synthetic material is more effective). If the contracture of the Achilles tendon is serious, after the inversion and pronation of the foot is completely corrected, the last percutaneous Achilles tendon is cut, and then the Dennis-Browne brace is applied for about 2 years.
(ii) Surgical treatment
It should be performed around one year of age.
1.Turco posterior medial soft tissue release: i.e. posterior medial soft tissue release with internal fixation by Kirschner pins. The basic principle is to completely release all contracted soft tissues of the posterior medial side, to prevent damage to the articular cartilage surface when cutting the joint capsule, and finally to reset the navicular bone, and to fix it by inserting a Kirschner needle through the first metatarsal bone, the first cuneiform bone, navicular bone and talus bone.
The surgical incision is made from the base of the first metatarsal, via the medial ankle, 8-10 cm in length; the posterior tibial tendon, the flexor digitorum longus tendon and the posterior tibial vascular nerve bundle are exposed, the flexor digitorum longus tendon, the Achilles tendon and the posterior talofibular ligament are found, and the general neurovascular bundle is located below the flexor digitorum longus tendon, which should also be fully free. The procedure is performed in three steps.
Posterior release: It helps to expose the medial and metatarsal contractures, first Z-shaped Achilles tendon extension, the lower end of the Achilles tendon is cut from the medial side, then the posterior tibial talofibular joint capsule is released, the heel-fibular ligament and subtalar joint capsule are cut, the neurovascular Cambodian is lifted, and the attachment point of the deltoid ligament on the heel bone is reached inwardly and anteriorly. Then, the heel ligament was released.
Medial release: Z-shaped extension of the posterior tibial tendon at the attachment point of the posterior tibial muscle and release of the Master’s node, severing the superficial portion of the deltoid ligament, the talofibular capsule and the spring ligament, followed by incision of the navicular wedge and the medial cuneiform-plantar joint capsule.
Sub talar release: complete release of the anterior aspect of the heel and navicular bone, release of the sub talar interosseous ligament and the Y-shaped ligament from the heel to the lateral edge of the navicular bone and the medial edge of the dice bone. After completion of these three releases, the foot deformity can be easily corrected, and when the talonavicular relationship is squared off, a kerf pin is inserted for fixation. The cast was removed and stitches removed at 6 weeks, and the Kirschner pin was removed and continued to be fixed in the corrected position with a new cast for 6 weeks. After removal of the cast, the leg was protected with a Dennis-Browne brace for 1 year at night.
2, McKay surgery: In the early 1980s, McKay proposed the new concept of rotation of the talocrural joint in all three planes of the clubfoot, i.e., foot drop in the sagittal plane, heel inversion in the coronal plane, and internal rotation in the horizontal plane. Due to the horizontal internal rotation, the anterior part of the heel bone slides below the talar head and neck, while the posterior tuberosity of the heel bone moves outward to the external ankle, and the heel bone undergoes simultaneous internal rotation in the coronal right plane.
This movement of the posterior part of the heel to the fibula in contact is due to internal rotation of the talocrural joint horizontally and is not due to foot drop and internal rotation of the heel and tibia, with posterior displacement of the fibula in appearance. The previous posterior medial release surgery neglected the horizontal talocrural joint and full foot internal rotation, so the deformity was often left after surgery, based on this understanding attention was paid to correct the internal rotation deformity of the talocrural joint.
The patient is placed prone, and a U-shaped incision (Cincinnati incision) is made at the back of the foot, starting from the navicular joint through the superior Achilles tendon and reaching the lateral side of the foot, performing posterior, medial and lateral soft group release, lengthening the Achilles tendon, lengthening the posterior tibial tendon, lengthening the flexor digitorum longus tendon and flexor digitorum longus tendon if necessary, and cutting the corresponding joint capsule, paying attention to protecting the lateral heel-fibular ligament and the posterior talofibular ligament, and medially paying attention to protecting the posterior tibial nerve and blood vessels. The lateral heel-fibular ligament and the posterior talofibular ligament are protected, and the medial heel nerve and blood vessels are protected, and the triangular ligament, the dorsal talofibular ligament, the metatarsal spring ligament and the medial capsules are cut. After cutting the heel and talar joint capsule, when foot drop cannot be corrected, the posterior talofibular ligament, tibiofibular ligament and deep deltoid ligament should also be cut until they are completely released.
Ideally, to correct the deformity of the foot, in order to maintain the stability of the foot, the talus, navicular, cuneiform, and first metatarsal bones are pierced with a Kirschner’s pin, and 2 Kirschner’s pins are pierced from below the heel bone and fixed in the talus, and then the angle of intersection between the double ankle line and the longitudinal axis of the foot is checked up to 85o~90o. After the operation, a long-leg cast in the knee flexion position is played, and the cast is removed in 6 weeks, and the Kirschner’s pins are withdrawn to practice the function of the ankle joint. This method is sometimes difficult to suture because the incision is too tight and needs to be temporarily placed in mild plantarflexion position and corrected after 2 weeks.
(iii) Complications of surgical treatment
1, postoperative foot in the cast retraction or fall off: is often one of the reasons for poor results, especially young, obese children are very easy to foot retraction or fall off, if not timely treatment, can occur “rocking chair bottom” deformity. In order to prevent can play knee flexion position long leg cast, but sometimes it is still difficult to avoid, the most reliable method is from the heel bone transverse line through a Kirschner needle, the needle fixed in the cast outside, so that it is foolproof.
2, poor wound healing and plaster pressure sores: poor wound healing mostly occurs after, inside and outside the U-shaped incision, so some improved literature reports that the second stage of correction after the wound has healed. Another fight is to play the plaster too tight wide especially in the dorsal foot, under the ankle area prone to plaster pressure sores, should add more cotton pads when playing the plaster.
3, deformity correction is not satisfactory or deformity recurrence: prevention lies in the surgery to loosen thoroughly.
4.Distant talar and navicular deformity: it is the pathological basis for affecting the function of the ankle joint and causing distant osteoarthritis. Anyone whose talar skid becomes flat and who cannot land on the heel when squatting should be given sufficient attention.