You are in: eMedicine Specialties > Orthopedic Surgery > PEDIATRICS Congenital Vertical TalusArticle Last Updated: Mar 20, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Jeffrey D Thomson, MD, Assistant Professor, Department of Orthopedic Surgery, University of Connecticut; Director of Orthopedic Surgery, Department of Pediatric Orthopedic Surgery, Connecticut Children's Medical Center Jeffrey D Thomson is a member of the following medical societies: American Academy of Orthopaedic Surgeons Editors: Mininder S Kocher, MD, MPH, Associate Professor of Orthopedic Surgery, Harvard Medical School/Harvard School of Public Health; Associate Director, Division of Sports Medicine, Department of Orthopedic Surgery, Children's Hospital Boston; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; George H Thompson, MD, Professor of Orthopedic Surgery and Pediatrics, Department of Pediatric Orthopedic Surgery, Case Western Reserve University; Director, Rainbow Babies and Children's Hospital; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Dennis P Grogan, MD, Clinical Professor, Department of Orthopedic Surgery, University of South Florida College of Medicine; Chief of Staff, Department of Orthopedic Surgery, Shriners Hospital for Children of Tampa Author and Editor Disclosure Synonyms and related keywords: CVT, congenital convex pes valgus, congenital rigid rocker-bottom foot, flatfoot, Persian slipper, dislocated navicular, oblique talus INTRODUCTIONSection 2 of 11
  Congenital vertical talus (CVT) is an uncommon disorder of the foot, manifested as a rigid rocker-bottom flatfoot. Its characteristic radiographic feature is a dorsal dislocation of the navicular on the talus. If left untreated, CVT results in a painful and rigid flatfoot with weak push-off power. CVT has been referred to in the literature by several synonyms, including congenital convex pes valgus. History of the ProcedureClosed treatment, consisting of manipulation and casting, was the earliest form of treatment. Limited surgery was sometimes additionally employed. Lamy and Weissman (1939) recommended excision of the talus, while Eyre-Brook (1967) advocated excising the navicular. Today, neither of these techniques is accepted as a definitive treatment. Several authors, beginning with Osmond-Clarke (1956), Herndon and Heyman (1963), and Coleman and associates (1970), described staged, 2-incision reconstructive surgery. The first stage of the Coleman procedure consisted of lengthening the extensor digitorum longus (EDL), extensor hallucis longus (EHL), and tibialis anterior, with capsulotomies of the talonavicular and calcaneocuboid joints and release of the talocalcaneal interosseous ligament. The second stage consisted of tendo-Achilles lengthening (TAL) and a posterior capsulotomy of the ankle and subtalar joints. After noting a high incidence of complications with the 2-stage technique, Ogata and colleagues (1979) recommended a single-stage procedure with a medial approach. Kodros and Dias (1999) published results they derived using a single-stage approach with a Cincinnati incision. In 1987, Seimon described a single-stage dorsal approach in which the EHL and peroneus tertius were tenotomized and the talonavicular joint was opened. The talonavicular joint was reduced and held with a Kirschner (K) wire. The Achilles tendon was lengthened percutaneously. Stricker and Rosen (1997) published their experience with this technique, as did Mazzocca and associates (2001); both groups noted excellent results with few complications. The trend toward less surgery for CVT continued with Dobbs and colleagues, who in 2006 published their technique of casting; percutaneous K-wire pinning of the talonavicular joint; and percutaneous heel-cord tenotomy. No patients had extensive soft-tissue releases, although some required lengthening of the anterior tibialis or the peroneus brevis tendon. Casting without pinning of the talonavicular joint was associated with recurrence of deformity. ProblemCVT is defined by an irreducible and rigid dorsal dislocation of the navicular on the talus. If the navicular is reducible on the lateral maximum plantarflexion radiograph, it is deemed an oblique talus, which is better treated with TAL and orthotics. FrequencyCVT is an uncommon disorder. In a 1983 literature review, Jacobsen and Crawford (1983) reported only 273 cases. Some have estimated the incidence of CVT to be one tenth that of congenital clubfoot. EtiologyThe etiology is unknown, but CVT frequently is associated with a wide variety of neuromuscular disorders. Ogata and associates proposed a CVT classification system that divides patients into 3 groups: idiopathic, genetic/syndromic, and neuromuscular. PathophysiologyThe hallmark of the deformity is an irreducible and rigid dorsal dislocation of the navicular on the talus. Seimon hypothesized that a contracture of the tendo-Achilles posteriorly creates equinus of the calcaneus, with increased verticality of the talus, while contracture of the EDL (and sometimes the EHL and tibialis anterior) pulls the navicular onto the dorsum of the navicular. ClinicalClinically, CVT presents as a rigid flatfoot with a rocker-bottom appearance of the foot. The calcaneus is in fixed equinus, and the Achilles tendon is very tight. The hindfoot is in valgus, while the head of the talus is found medially in the sole, creating the rocker-bottom appearance. The forefoot is abducted and dorsiflexed. The foot is stiff. In ambulatory children, calluses can develop under the head of the talus, which is very prominent along the plantar-medial foot. Associated genetic syndromes must be excluded; therefore, a consultation with a pediatric geneticist may be indicated. INDICATIONSSection 3 of 11
Surgery is indicated when the talonavicular joint is found, after a trial of serial casting, to be unreducible. Although most patients require surgical intervention, serial casting with the foot in plantarflexion may occasionally be successful. More importantly, serial casting helps to stretch out the contracted dorsal skin, tendons, and joint capsules, which should be helpful at the time of surgery. Lateral radiographs of the foot in maximal plantarflexion can reveal if the navicular is reducible. RELEVANT ANATOMYSection 4 of 11
A rigid, irreducible talonavicular dislocation is the hallmark of CVT. Contractures of the tendo-Achilles posteriorly and the EDL and dorsal talonavicular capsule anteriorly are common. In feet with greater involvement or in older children, more contractures and deformity are present (eg, contractures of the tibialis anterior and EHL anteriorly, peroneus tertius and inferior retinaculum of the ankle anterolaterally, peroneus brevis and longus laterally with the calcaneofibular ligament, and the tibiotalar joint posteriorly). Coleman divided CVT into 2 types: type 1 was associated with a calcaneocuboid dislocation, and type 2 was not. This distinction is important clinically because the type 1 deformity is stiffer and particular attention must be paid to releasing the calcaneocuboid joint. CONTRAINDICATIONSSection 5 of 11
If the talonavicular joint is reducible on the lateral maximum plantarflexion view radiograph, surgery is probably not needed. In these cases, TAL and orthotics, such as a University of California Berkeley Laboratory (UCBL) orthosis, may be effective. WORKUPSection 6 of 11
Imaging Studies
TREATMENTSection 7 of 11
Medical therapySerial casting should be the initial treatment, although prior to the Dobbs article, it was usually thought to be unsuccessful. Serial casting should be used to stretch the foot in plantarflexion and inversion while counterpressure is applied to the medial aspect of the talus. Elongating and stretching the talonavicular joint in order to facilitate its reduction is important in avoiding compression of the dorsally displaced navicular into the talus. A long leg cast is then applied, with the knee flexed 90° to prevent the cast from slipping. The cast should be changed frequently (about every 1-2 wk) in order to maximize its effectiveness. According to the Dobbs technique, if the navicular can be manipulated into the correct alignment relative to the talus, it can then be pinned with a K-wire to maintain the reduction. A small incision can be made over the talonavicular joint, and the joint can be reduced via an open technique if there is any difficulty with the reduction. A percutaneous heel-cord tenotomy is always performed. The K-wire is left in place for a total of 5 weeks, and the position is held with a long leg cast, which is changed 2 weeks after surgery. A postoperative brace is worn 23 hours per day until walking age, and then it is worn for walking until age 2. (Please see the article by Dobbs and colleagues for complete surgical and postoperative management details.) Surgical therapyA single-stage surgical correction is another option and can be accomplished via either the Cincinnati approach or the dorsal approach. The author generally prefers the dorsal approach, as described by Seimon; however, the author also prefers the Ollier-type incision. Preoperative detailsSome orthopedists find it useful to cast the foot preoperatively in order to stretch out the dorsal structures, but casting rarely is associated with permanent correction. Intraoperative detailsIn the author's preferred technique, dissection is performed under tourniquet control, and the superficial peroneal and sural nerves are identified and protected. The author typically finds a contracted peroneus tertius, which is released, as well as an abnormal band of the inferior retinaculum causing a tether from the tibia to the calcaneus. The dorsalis pedis vein and artery and the deep branch of the peroneal nerve are protected, while the tibialis anterior, EHL, and extensor digitorum communis (EDC) are retracted. The talonavicular joint is visualized and opened dorsally, medially, and laterally. The calcaneocuboid joint also is opened along its dorsal, medial, and lateral aspects. Occasionally, the peroneus longus and brevis require lengthening. The EHL and EDC can be lengthened, but this is not always necessary. Some advocate transferring the tibialis anterior to the talus. A percutaneous tendo-Achilles tenotomy is performed. The author has not found it to be necessary to perform an open capsulotomy of the tibiotalar (ankle) joint. A 0.062-in K-wire is used to hold the talonavicular joint. A talocalcaneal wire typically is not used, nor is it necessary. The author finds it easier to drive the K-wire antegrade into the navicular, through the cuneiform, and out dorsally through the first metatarsal. The talonavicular joint is reduced, and the K-wire is then driven retrograde across the talonavicular joint. The K-wire is cut and buried, and the foot is splinted in a long leg splint for about 10 days to 2 weeks to allow the swelling to decrease. At that point, the patient is put into a long leg cast, with the ankle in neutral position. Postoperative detailsThe K-wire is removed 8 weeks after surgery, and a walking short leg cast then is used for about 2-4 weeks. No postoperative brace is used. Follow-upThe author does not generally use a postoperative brace or orthosis for idiopathic CVT. Postoperative bracing is advised for children with myelodysplasia, arthrogryposis, or other syndromes to maintain correction and prevent recurrence. COMPLICATIONSSection 8 of 11
Complications can occur around the time of surgery (perioperatively) or can manifest early or late in the postoperative period. Common complications in the perioperative period include infection, wound-healing problems, and skin slough; however, these complications are not unique to CVT. In the first year or two after surgery, the deformity can recur, usually secondary to undercorrection. Undercorrection can occur because of incomplete talonavicular reduction, insufficient posterior ankle release, or residual forefoot abduction (Stricker and Rosen). Recurrence of the deformity can also be attributable to neurologic causes, especially in patients with spina bifida. Kodros and Dias reported a high recurrence rate in patients with spina bifida and believed that in these cases the recurrences might be secondary to a tethered spinal cord or other neurologic abnormality. Avascular necrosis (AVN) of the talus is a unique complication of CVT surgery. It was more often reported in the older literature and was associated with the 2-stage release and extensive surgery. In more recent years, articles by Kodros and Dias, Seimon, Stricker and Rosen, and Mazzocca and colleagues have not reported occurrences of AVN of the talus. Late complications include restricted range of motion of the foot and ankle, which can contribute to calf muscle atrophy. This in turn can lead to easy fatigue of the affected limb. OUTCOME AND PROGNOSISSection 9 of 11
In general, the outcome and prognosis are good. Some minor calf atrophy and foot size asymmetry occur and are more noticeable in unilateral cases. Ankle range of motion is about 75% of normal. If AVN of the talus occurs, the results are less optimal because of ankle pain, stiffness, and weakness. FUTURE AND CONTROVERSIESSection 10 of 11
It is hoped that in the future, the amount of dissection can be minimized, reducing the incidence of AVN and, in turn, improving the overall outcome. Early diagnosis to allow for surgical correction in infants younger than 2 years also should help to improve results. Controversy exists over the choice of surgical approaches. However, the author believes that the choice of structures to be released is a more important factor in determining outcomes than is the choice of incisions to be used. Special attention must be paid to the dorsal and dorsolateral contracted tissues. Controversy also exists over the need for an anterior tibialis tendon transfer. REFERENCESSection 11 of 11
Congenital Vertical Talus excerpt Article Last Updated: Mar 20, 2007 |
