The Foot in Apert Syndrome

Two-stage surgical treatment for medially angulated great toes in Apert feet by wedged corrective osteotomy with distraction of the inter-metatarsal space: A case report

BACKGROUND

One of most severe clinical problems related to Apert foot anomalies is medial angulation deformities of the great toe as the foot grows.

CASE PRESENTATION

The patient was a 22-month-old Japanese child with Apert syndrome, who had broad bilateral great toe showing medially angulated deformity. We performed two-stage surgical treatment including distraction of the remarkable narrowing the first inter-metatarsal space using an external distractor device, and the corrective wedge-osteotomy of the first metatarsal with a graft of wedged bone in the reverse direction and inter-positioning of the resected local bone between the first and second metatarsal to preserve the space. At 3 years after surgery, the patient did not have any disturbance of gait and could wear normal shoes without weight-bearing pain, and was satisfied with the appearance of the great toes.

CONCLUSION

The two-stage surgical method could be an option for surgical treatment of Apert feet.

Fracture through Pre-Existing Tarsal Coalition: A Narrative Review

Tarsal coalitions are abnormal fibrous or bony connections between the tarsal bones of the foot. While not always symptomatic, coalitions can cause pain, alterations in forefoot and hindfoot morphology, and alterations in foot and ankle biomechanics. Previous research has described the association of tarsal coalitions with fractures of the lower extremity. Multiple reports of acute fracture in the presence of tarsal coalition have been presented, as have reports of stress fractures of the foot and ankle with concomitant coalition, insidious in onset and thought to be related to aberrancies in foot and ankle biomechanics. The purpose of this review is to discuss the biomechanics seen in tarsal coalitions and to describe reports of fracture occurring concomitantly with tarsal coalitions. We will discuss diagnostic options and treatment approaches in the setting of fracture with preexisting tarsal coalition.

[The Apert Foot: Anatomical Changes, Classification, Thoughts on surgical Treatment]

Diagnosis and therapy of the Apert foot are scarcely described in extant literature. This article describes anatomical changes observed in 30 Apert feet. By analysis of X-rays and computed scans 5 types of bony Apert foot malformations were identified. We developed therapeutic recommendations based on this classification.

Is the Apert foot an overlooked aspect of this rare genetic disease? Clinical findings and treatment options for foot deformities in Apert syndrome

BACKGROUND

Apert syndrome is characterised by the presence of craniosynostosis, midface retrusion and syndactyly of hands and feet, thus, synonymously referred to as acrocephalosyndactyly type I. Considering these multidisciplinary issues, frequently requiring surgical interventions at an early age, deformities of the feet have often been neglected and seem to be underestimated in the management of Apert syndrome. Typical Apert foot features range from complete fusion of the toes and a central nail mass to syndactyly of the second to fifth toe with a medially deviated great toe; however, no clear treatment algorithms were presented so far. This article reviews the current existing literature regarding the treatment approach of foot deformities in Apert syndrome.

STATE-OF-THE-ART TOPIC REVIEW

Overall, the main focus in the literature seems to be on the surgical approach to syndactyly separation of the toes and the management of the great toe deformity (hallux varus). Although the functional benefit of syndactyly separation in the foot has yet to be determined, some authors perform syndactyly separation usually in a staged procedure. Realignment of the great toe and first ray can be performed by multiple means including but not limited to second ray deletion, resection of the proximal phalanx delta bone on one side, corrective open wedge osteotomy, osteotomy of the osseous fusion between metatarsals I and II, and metatarsal I lengthening using gradual osteodistraction. Tarsal fusions and other anatomical variants may be present and have to be corrected on an individual basis. Shoe fitting problems are frequently mentioned as indication for surgery while insole support may be helpful to alleviate abnormal plantar pressures.

CONCLUSION

There is a particular need for multicenter studies to better elaborate surgical indications and treatment plans for this rare entity. Plantar pressure measurements using pedobarography should be enforced in order to document the biomechanical foot development and abnormalities during growth, and to help with indication setting. Treatment options may include conservative means (i.e. insoles, orthopedic shoes) or surgery to improve biomechanics and normalize plantar pressures.

LEVEL OF EVIDENCE

Level V.

Minimally Invasive Hallux Interphalangeal Joint Arthrodesis for Hallux Varus in Pfeiffer Syndrome: A Case Report

Pfeiffer syndrome is a rare hereditary condition with an autosomal dominant transmission caused by a mutation that affects fibroblast growth factor receptors. It is one of the acrocephalosyndactyly diseases causing cranial malformations owing to early suture fusion. In the foot, it is typically associated with hallux varus, first ray hyperplasia, and partial lesser digit syndactyly. We report a clinical case of a 10-year-old patient with Pfeiffer type I syndrome with bilateral severe hallux varus due to a hypoplastic trapezoidal shaped proximal phalanx, a distal, medial-facing articular surface, and interphalangeal instability. This deformity was addressed by minimally invasive hallux interphalangeal joint arthrodesis with internal and external fixation. We report the results at the 2-year follow-up point.

Short stature, unusual face, delta phalanx, and abnormal vertebrae and ribs in a girl born to half-siblings

Delta phalanx is a rare abnormality typically associated with additional features. We describe a patient with a phenotype resembling Catel-Manzke syndrome, but with delta phalanx and abnormal vertebrae and ribs. The patient was the only child of half siblings born with a marked prenatal growth deficiency. At 10 years of age, she had a short stature, long face, long and tubular nose with small alae nasi, high palate, short and broad thorax, and short index fingers with radial deviation. There were hyperpigmentations following Blaschko's lines. Radiology showed a proximal delta phalanx in the index finger of hands, abnormal vertebrae, and fused and small ribs. GTG-Banding karyotype and microarray analysis yielded normal results. Exome sequencing identified 25 genes that harbored homozygous variants, but none of these is assumed to be a good candidate to explain (part of) the phenotype. The here described patient may have a new condition, possibly following an autosomal recessive pattern of inheritance, although due to the high degree of consanguinity a compound etiology of the phenotype by variants in various genes may be present as well.

Correction of Brachymetatarsia and Medial Angulation of the Great Toe of Apert Foot By Distraction Osteogenesis: A Review of 7 Years of Experience

BACKGROUND

Apert foot anomalies may cause severe problems such as pain and development of callus formation related to weight redistribution, problems with footwear, and gait disturbances that may limit their daily activities. The main purpose of this study was to review our experience with distraction osteogenesis for the correction of brachymetatarsia and the great toe angulation of the patients with Apert syndrome.

METHODS

This study retrospectively reviewed 7 patients (14 extremities) followed up for Apert syndrome who underwent distraction for the correction of bilateral congenital brachymetatarsia and angulation of the great toe between 2004 and 2008. Correction of the metatarsal inclination angle, the medial angulation of the great toe, the percentage of lengthening, and lengthening rates of distracted bones were evaluated.

RESULTS

Patients ranged in age from 4 to 8 years at the distraction operation, with a mean age of 5.4±1.3 years, and the average length of follow-up was 86.6±21.0 months. The length of the first metatarsal bone increased significantly from the average length of 32.6±5.7 mm to an average of 46.7±6.5 mm (P<0.001). The mean lengthening rate and lengthening percentages of distracted bones were 0.4%±0.1%/month and 30.2%±6.4%/month, respectively. Preoperative and postoperative metatarsal inclination angles were at a mean of 43.8±5.12 and 32.6±3.8, respectively, and the correction of metatarsal inclination was considered as statistically significant (P<0.001). The mean angulation of the great toe reduced significantly from 49.8±11.76 to 13.2±8.5 degrees after distraction (P<0.001). Minor complications such as pin loosening, pin-tract infection, and early union that required reoperation were observed in 5 extremities (35.7%).

CONCLUSIONS

Anatomic features of Apert foot may lead to complaints that may limit patients' daily activities and require as much attention as associated hand and craniofacial anomalies. Distraction appears to be an effective and safe approach for the simultaneous correction of the shortness of the first ray and medial angulation of the great toe.

LEVEL OF EVIDENCE

Level IV.

Ulnar Polydactyly in Apert’s Syndrome

Finger duplication is not a known feature of Apert’s syndrome. A case of Apert’s syndrome with unilateral duplication of the little finger is described. The literature is reviewed and similar cases are discussed.

Subtalar coalition in pediatrics

Subtalar tarsal coalition is an autosomal dominant developmental maldeformation that affects between 2% and 13% of the population. The most common locations are between the calcaneus and navicular and between the talus and calcaneus. If prolonged attempts at nonoperative management do not relieve the pain, surgery is indicated. The exact surgical technique(s) should be based on the location of the pain, the size and histology of the coalition, the health of the other joints and facets, the degree of foot deformity, and the excursion of the heel cord.

Talocalcaneal coalition in Muenke syndrome: report of a patient, review of the literature in FGFR-related craniosynostoses, and consideration of mechanism

Muenke syndrome is an autosomal dominant craniosynostosis syndrome resulting from a defining point mutation in the Fibroblast Growth Factor Receptor3 (FGFR3) gene. Muenke syndrome is characterized by coronal craniosynostosis (bilateral more often than unilateral), hearing loss, developmental delay, and carpal and/or tarsal bone coalition. Tarsal coalition is a distinct feature of Muenke syndrome and has been reported since the initial description of the disorder in the 1990s. Although talocalcaneal coalition is the most common tarsal coalition in the general population, it has never previously been reported in a patient with Muenke syndrome. We present a 7-year-old female patient with Muenke syndrome and symptomatic talocalcaneal coalition. She presented at the age of 7 with limping, tenderness and pain in her right foot following a fall and strain of her right foot. She was treated with ibuprofen, shoe inserts, a CAM walker boot, and stretching exercises without much improvement in symptoms. A computed tomography (CT) scan revealed bilateral talocalcaneal coalitions involving the middle facet. She underwent resection of the talocalcaneal coalitions, remaining pain-free post-operatively with an improvement in her range of motion, gait, and mobility. This report expands the phenotype of tarsal coalition in Muenke syndrome to include talocalcaneal coalition. A literature review revealed a high incidence of tarsal coalition in all FGFR related craniosynostosis syndromes when compared to the general population, a difference that is statistically significant. The most common articulation involved in all syndromic craniosynostoses associated with FGFR mutations is the calcaneocuboid articulation.

Impact of genetics on the diagnosis and clinical management of syndromic craniosynostoses

PURPOSE

More than 60 different mutations have been identified to be causal in syndromic forms of craniosynostosis. The majority of these mutations occur in the fibroblast growth factor receptor 2 gene (FGFR2). The clinical management of syndromic craniosynostosis varies based on the particular causal mutation. Additionally, the diagnosis of a patient with syndromic craniosynostosis is based on the clinical presentation, signs, and symptoms. The understanding of the hallmark features of particular syndromic forms of craniosynostosis leads to efficient diagnosis, management, and long-term prognosis of patients with syndromic craniosynostoses.

METHODS

A comprehensive literature review was done with respect to the major forms of syndromic craniosynostosis and additional less common FGFR-related forms of syndromic craniosynostosis. Additionally, information and data gathered from studies performed in our own investigative lab (lab of Dr. Muenke) were further analyzed and reviewed. A literature review was also performed with regard to the genetic workup and diagnosis of patients with craniosynostosis.

RESULTS

Patients with Apert syndrome (craniosynostosis syndrome due to mutations in FGFR2) are most severely affected in terms of intellectual disability, developmental delay, central nervous system anomalies, and limb anomalies. All patients with FGFR-related syndromic craniosynostosis have some degree of hearing loss that requires thorough initial evaluations and subsequent follow-up.

CONCLUSIONS

Patients with syndromic craniosynostosis require management and treatment of issues involving multiple organ systems which span beyond craniosynostosis. Thus, effective care of these patients requires a multidisciplinary approach.

Associated talocalcaneal and calcaneonavicular coalitions in the same foot

Tarsal coalition represents abnormal fusion among two or more tarsal bones and is a frequent cause of foot and ankle pain. The coexistence of calcaneonavicular and talocalcaneal coalitions in the same foot has been rarely cited in the literature. We report three cases of rigid flatfoot associated to a double coalition in the same foot. Routine computed tomography (CT) scan helped to delineate the joint space narrowing and bony bridges for preoperative planning. All cases were treated surgically with lateral and medial approach, bar resection, and extensor digitorum brevis interposition. Resection of such coalitions produced variable clinical and radiographic results. The authors discuss the frequency of multiple tarsal bars and the importance of CT in preoperative planning. Multiple tarsal coalitions in the same foot are probably not rare. Surgical outcomes can be jeopardized if they are not recognized in advance. The detection, localization, and characterization of this entity with routine CT scan are mandatory in patients undergoing surgery.

LEVEL OF EVIDENCE

IV.

[Malformations of the lower extremities]

Malformations with deficiencies of the lower extremities are rare. They are usually caused by toxic influences during pregnancy between the 4th and the 12th week of gestation. Some malformations have a genetic origin. The total incidence of congenital deficiencies of the lower extremities is approximately 18 in 100,000 newborns. The most common deficiencies are fibular hemimelias, followed by congenital femoral deficiencies and tibial hemimelias. Hemimelias are often associated with deficient toes or ray defects. Congenital pseudarthrosis of the tibia is less common, but this diagnosis is underestimated in epidemiological studies in neonates, because the fracture usually only occurs at walking age. Other deficiencies such as bladder exstrophy with pelvic defects, split feet and defects in association with hereditary skeletal dysplasias (Apert syndrome, constriction band syndrome) are extremely rare. Various treatment options are available, including shoe elevation, orthotic or prosthetic devices, realignment osteotomy, arthrodesis, rotationplasty, amputation and surgical leg lengthening. Complex deformities should be treated by a team of specialists such as orthopedic surgeons, orthotists, physiotherapists, psychologists and possibly other surgeons too.

Treatment of the hands and feet in Apert syndrome: an evolution in management

Apert syndrome is a relatively uncommon condition that is instantly recognizable on the basis of the pan-syndactylies involving both the hands and feet. For more than 10 years, the treatment of Apert syndrome hand and foot anomalies was approached in a comprehensive manner, with attempts to maximize the final results and minimize the total number of operations. Numerous conventions were abandoned in the development of this approach, with the introduction of some new methodologies, including (1) release of all 10 fingers, and toes, in only two operations, (2) elimination of routine digital amputations, (3) abandonment of the zigzag incision in favor of straight-line release, (4) substitution of equal-length anterior and posterior flaps for the long dorsal web space lining flap, (5) leaving of small areas of exposed bone without vascularized tissue coverage, and (6) performance of midphalangeal osteotomies, among older children, to improve hand function. Fifty-seven children with Apert syndrome have been treated at the author's center since 1990, and 43 underwent surgical treatment of their hands and feet by a single surgeon. Treatment can be separated into two phases, early (syndactyly releases) and late (functional osteotomies). Seventeen of those 43 patients were treated at the author's center from birth (type I, 11 patients; type II, two patients; type III, four patients), and 10 fingers and 10 toes were achieved for all patients in two operations. No digital amputations were performed for any of the 43 patients. However, four of 26 patients (15 percent) not treated at the author's center from birth had undergone at least one digital amputation before coming to the center. Twenty-two of those 26 patients required a two-stage syndactyly release to accomplish the separation of all 10 fingers and toes. Aside from the patients who had previously undergone amputations, all other patients successfully achieved 10 fingers and toes, except for one patient (38 of 39 patients, 97 percent). The average operative time for the first-stage syndactyly release of the hands and feet was 4 hours 11 minutes (range, 185 to 300 minutes), and that for the second stage was 3 hours 49 minutes (range, 160 to 300 minutes). Twenty-eight hands were treated with functional osteotomies, which involved permanent angulation of the fused phalanges at the proximal interphalangeal level, to create a "position of function" and provide pulp-to-pulp pinch. In addition, targeted osteotomies of the feet were performed for many of these patients, to decrease pain with walking. There were no major complications. Minor complications included one reexploration because of bleeding, early in the series. There were 13 incomplete secondary syndactylies that required a subsequent operative release (10 spaces treated at the author's center and three treated elsewhere), of a total of 342 spaces (3 percent author incidence). There were no scar contractures or functional limitations that required release. This distinctive protocol seemed to result in improved functional outcomes, with a reduction in the total number of operative procedures.

Differential expression of fibroblast growth factor receptors in human digital development suggests common pathogenesis in complex acrosyndactyly and craniosynostosis

The Apert hand is characterized by metaphyseal fusions of the metacarpals and distal phalanges, symphalangism, and soft-tissue syndactyly. More subtle skeletal anomalies of the limb characterize Pfeiffer and Crouzon syndromes. Different mutations in the fibroblast growth factor receptor 2 (FGFR2) gene cause these syndromes, and offer the opportunity to relate genotype to phenotype. The expression of FGFR1 and of the Bek and KGFR isoforms of FGFR2 has, therefore, been studied in human hand development at 12 weeks by in situ hybridization. FGFRs are differentially expressed in the mesenchyme and skeletal elements during endochondral ossification of the developing human hand. KGFR expression characterizes the metaphyseal periosteum and interphalangeal joints. FGFR1 is preferentially expressed in the diaphyses, whereas FGFR2-Bek expression characterizes metaphyseal and diaphyseal elements, and the interdigital mesenchyme. Apert metaphyseal synostosis and symphalangism reflect KGFR expression, which has independently been quantitatively related ex vivo to the severity of clinical digital presentations in these syndromes. Studies in avian development implicate FGF signaling in preventing interdigital apoptosis and maintaining the interdigital mesenchyme. Herein is proposed that in human FGFR syndromes the balance of signaling by means of KGFR and Bek in digital development determines the clinical severity of soft-tissue and bony syndactyly.

Ectrodactyly, soft-tissue syndactyly, and nodulocystic acne: coincidence or association?

We report severe nodulocystic acne in a 21-year-old man associated with ectrodactyly of the right foot and soft-tissue syndactyly of the third and fourth left fingers, and the first to fourth left toes. His acne was resistant to conventional topical (clindamycin phosphate, erythromycin, tretinoin, peeling agents) and systemic (tetracycline, erythromycin) antiacne medications. Moderate improvement was achieved with systemic isotretinoin. Apart from presenting this case, we imply the disparity of the clinical characteristics of our case and those of Apert syndrome, a rare congenital condition with craniofacial anomalies, symmetric syndactyly of the digits, and acneiform eruption. We discuss the possible explanation for the association of acne lesions and bone deformities based on recent reports of mutations of fibroblast growth factor receptor 2 in the great majority of patients with this syndrome, as well as current experimental data on the involvement of the keratinocyte growth factor in the process of hair follicle growth, development, and differentiation.

Classification of hand anomalies in Apert's syndrome

The literature states that all patients with Apert's syndrome should have complex (osseous) syndactyly of the index, middle and ring fingers. We describe a case of Apert's syndrome with simple syndactyly and recommend extending the classification of hand anomalies in Apert's syndrome.

Hands and feet in the Apert syndrome

We studied 44 pairs of hands and 37 pairs of feet in Apert syndrome, utilizing clinical, dermatoglyphic, and radiographic methods. We also studied histologic sections of the hand from a 31-week stillborn fetus. Topic headings discussed include: clinical classification of syndactyly; correlations between types of hands and feet in the same patient; dermatoglyphics; anatomy of the hand; radiologic assessment; comparison with other studies; histologic assessment of the hand; acrocephalosyndactyly vs. acrocephalopolysyndactyly: a pseudodistinction; and some generalizations.

Spatial dysmorphology of the foot in Apert syndrome: three-dimensional computed tomography

Computer assisted medical imaging was used to define the spatial dysmorphology of the foot in three patients with Apert syndrome and to correlate that dysmorphology with ambulation and footwear. Thin slice (2 mm), abutting, high resolution axial computed tomography (CT) foot scans were obtained. The CT data were post processed, using Analyze, to generate three-dimensional surface shaded and volumetric reformations. The reformatted images were evaluated by a bone and joint radiologist to identify abnormalities of bone shape, size, and orientation, of joint morphology, and of the foot as a whole. Five consistent findings were observed among the three pairs of feet: (1) anomalous great toes with phalangeal and metatarsal pathology; (2) simple syndactyly of toes 2-5; (3) fusions between matatarsals; (4) tarsal coalitions; and (5) limitations in commercial footwear. One patient underwent bilateral fifth metatarsal wedge osteotomies to facilitate the wearing of shoes. The dysmorphology of the Apert foot is a combination of congenital malformations and postnatal deformations, secondary to progressive synostosis. Prophylactic foot surgery may be indicated in Apert patients to facilitate shoe fitting.