Anatomy and Management of the Leg and Foot in Apert Syndrome

[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.

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.

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.