|Year : 2019 | Volume
| Issue : 1 | Page : 4-10
Foot deformities and gait deviations in children with arthrogryposis
Lucio Perotti, Chris Church, Celina Santiago, Nancy Lennon, John Henley, Kristen Nicholson, Jose Salazar-Torres, Maureen Donohoe, Kathryn Fazio, Freeman Miller, Louise Reid Nichols
Department of Orthopedics, Gait Lab, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
|Date of Web Publication||23-Aug-2019|
Dr. Kristen Nicholson
Gait Lab, Nemours/Alfred I. duPont Hospital for Children, 1600 Rockland Rd, Wilmington, DE 19803
Source of Support: None, Conflict of Interest: None
Objectives: Arthrogryposis multiplex congenita is a congenital condition characterized by joint contractures with resulting foot deformities and gait deviations. The aim of this study was to describe gait deviations and foot deformities in children with arthrogryposis objectively and quantitatively with detailed gait analysis, including multisegment foot kinematics and foot pressure analysis. Materials and Methods: Children with arthrogryposis were evaluated retrospectively. Their data were compared to data from typically developing children. Comprehensive data presented include results of a full gait analysis with multisegment or single-segment foot kinematics, kinetics, pedobarograph, physical examination, and radiographic measurements. Children were grouped by age, orthotic use, and history of surgical intervention. Results: Forty-two children with arthrogryposis (2–20 years old) were reviewed. Physical examination and kinematic data showed that children walked with a crouched gait; exhibited stiffness in the hips, knees, and ankles; and showed limitations in their gross motor functioning. Power generation was low at the ankle and was high at the hip. Multisegment foot kinematics revealed stiffness in hindfoot plantar flexion and residual forefoot adduction. Foot pressure showed reduced heel impulse, excessive midfoot contact, and overall varus foot position. Categorization by age revealed greater stiffness at the hips and knees in older children. Children with knee–ankle–foot orthosis showed the most stiffness. Conclusions: Three-dimensional motion analysis and plantar pressure measurements are able to quantify the empirical observations of children with arthrogryposis walking with a crouched, stiff gait and having foot deformities. The use of these technologies in conjunction with clinical examination and functional tests is, therefore, recommended to monitor treatment efficacy and natural progression of gait deviations and joint deformities in arthrogryposis.
Keywords: Arthrogryposis, foot, gait, kinematics, pedobarograph
|How to cite this article:|
Perotti L, Church C, Santiago C, Lennon N, Henley J, Nicholson K, Salazar-Torres J, Donohoe M, Fazio K, Miller F, Nichols LR. Foot deformities and gait deviations in children with arthrogryposis. J Limb Lengthen Reconstr 2019;5:4-10
|How to cite this URL:|
Perotti L, Church C, Santiago C, Lennon N, Henley J, Nicholson K, Salazar-Torres J, Donohoe M, Fazio K, Miller F, Nichols LR. Foot deformities and gait deviations in children with arthrogryposis. J Limb Lengthen Reconstr [serial online] 2019 [cited 2020 Jan 26];5:4-10. Available from: http://www.jlimblengthrecon.org/text.asp?2019/5/1/4/265359
| Introduction|| |
Arthrogryposis multiplex congenita (AMC) is a heterogeneous condition comprising multiple congenital joint contractures, frequently leading to limitations in mobility and activities of daily living. Arthrogryposis occurs with a prevalence of 1:3000–1:5100 live births., The principal cause of arthrogryposis is decreased fetal movements (fetal akinesia) occurring as a result of fetal or maternal abnormalities, and there is a direct correlation between the severity of congenital contractures and the earlier onset of fetal akinesia.
Arthrogryposis can be principally classified as distal, radial dysplasia, amyoplasia, and Escobar syndrome. In amyoplasia, the most common subgroup of AMC (38%–43%), limb involvement varies, with all four limbs involved in 84% of children, only lower limbs involved in 11%, and only upper extremities involved in 5%.,, In amyoplasia, 85% of children are able to walk independently before the age of 5 years, but gait deviations are common.
AMC affects the capacity for ambulation, with varying functional levels classified according to Hoffer as community, household, nonfunctional, and nonambulators, but few studies have quantified gait deviations in this population. Motor function limitations and their relationship to muscular status and contractures were evaluated with a focus on static and qualitative measures, but the relationship between gait deviation and AMC has not been studied quantitatively. Recent studies have started using three-dimensional (3D) gait analysis to evaluate children with arthrogryposis. Bohm et al. used 3D motion analysis to evaluate gait in children with arthrogryposis, focusing on trunk motion and strength and range of motion of the hip. Eriksson et al. used 3D gait analysis to evaluate the Gait Deviation Index in children with arthrogryposis though limited information was available regarding dynamic foot movement. A quantitative understanding of overall lower extremity dynamics has the potential to increase understanding of functionality and ambulation capacity and evaluate treatment effectiveness.
Children with arthrogryposis frequently have foot deformities, which are often difficult to treat and have a high rate of recurrence., Clubfoot is a common foot deformity in arthrogryposis, but it has been found to be harder to treat than idiopathic clubfoot with high rate of recurrence and the need for further surgical intervention. Other common foot deformities in arthrogryposis include equinovarus foot and congenital vertical talus (CVT). These foot deformities can be debilitating if not treated, and studies have often focused on surgical or other treatments to determine the effectiveness of treatment;,,,,, however, the outcomes largely have been measured using radiographs or other static measures. This study seeks a more objective picture of the dynamic motion of the foot in children with arthrogryposis through foot pressure analysis and multisegment foot kinematics.
The aim of the present study was to retrospectively study clinical data from children with arthrogryposis to quantitatively assess lower extremity gait deviations and foot deformities. Accurate quantitative assessment of contractures and bony malalignment and their effect on foot deformity, gait, and functional mobility is essential for the treatment planning and management, including surgical intervention, in the AMC population.
| Materials and Methods|| |
In this institutional review board IRB-approved retrospective study, inclusion criteria were a diagnosis of arthrogryposis and the completion of a gait analysis. Data were collected from medical records from January 1998 to April 2016. Children's first gait laboratory visits were selected if multiple visits were available. Surgical history was not controlled or used as exclusion criteria but was collected from medical records. Gait data (foot pressure and 3D gait analysis) were captured in barefoot for all patients.
Children who had foot radiographs as part of their orthopedic evaluation were identified. Radiographic measurements of the foot on anteroposterior view included talocalcaneal angle., Radiographic measurements on the lateral view of foot included talo- first metatarsal angle,, talo-horizontal angle, talocalcaneal axial angle, and calcaneal pitch.,
Physical examination measurements evaluated lower extremity passive range of motion for hip abduction, knee flexion, ankle dorsiflexion, and ankle plantar flexion using a clinical goniometer. The range of motion measurements was described in Norkin and White's Measurement of Joint Motion: A Guide to Goniometry and Kendall et al.'s Muscles: Testing and Function with Posture and Pain. Children's gross motor function was scored using Section D of the Gross Motor Function Measure (GMFM). The GMFM Section D assesses children's gross motor skills related to standing ability on a 0–3 scale, where 0 = does not initiate, 1 = initiates, 2 = partially completes, and 3 = completes several skills. Children's functional mobility was scored using the Functional Mobility Scale (FMS). The FMS describes the functional mobility of the child over three distinct distances: in the home, at school, and in the wider community. Each distance receives a score of C for crawling or 1–6, with 1 being use of a wheelchair and 6 being independent on all surfaces.
Dynamic foot pressure readings were collected using a walkway pedobarograph (Tekscan, South Boston, MA, USA). Heel pressures, medial and lateral midfoot and forefoot pressure, and Coronal Plane Pressure Index (CPPI) were studied and compared to laboratory normative values. CPPI is the ratio of medial-to-lateral column pressure on a scale of −100 (severe varus) to +100 (severe valgus). Pedobarograph outcomes from three footprints were measured and averaged to obtain foot pressure data.
Gait analyses were completed in the motion analysis laboratory using 3D motion capture to analyze lower extremity movement during barefoot walking. Kinematic data were obtained using an eight-camera motion analysis system (Motion Analysis, Santa Rosa, CA, USA). Foot motion was measured with a single-segment foot marker set or with a multisegment foot marker set for children who could walk without an assistive device., Kinetics were calculated using data from two AMTI force plates (Advanced Mechanical Technology, Watertown, MA, USA). Single-segment kinematic and kinetic normative data were age matched. Multisegment foot normative data were from children with no reported foot deformity, motor disorder, or observable gait deviations.
Outcome variables were compared to data from typically developing (TD) children using unpaired t-tests. Children were grouped and compared as follows:
- Age: 2–9 years versus 10–20 years (unpaired t-test)
- Presentation type: As clubfoot and CVT present with opposing deformities that may cancel each other out if grouped and analyzed together, separate analyzes were carried out for each of these deformities
- Orthotic use: knee–ankle–foot orthosis (KAFO) versus ankle–foot orthosis (AFO) versus in-shoe or no orthotic (ANOVA with Bonferroni corrections)
- Equinovarus foot deformity treatment history: clubfoot with operative treatment versus clubfoot with conservative treatment (Ponseti technique; unpaired t-test).
| Results|| |
Forty-two children (84 total feet; mean age: 10 ± 5 years) met inclusion criteria. Of these 42 children, 19 were classified with amyoplasia, 17 with distal, 1 with radial dysplasia, and 3 with multiple pterygium, of which 2 were subclassified with Escobar syndrome. Two children did not have a specific classification on their medical notes.
FMS scores are provided in [Table 1].
Eleven percent of children used KAFOs, 44% used AFOs, and 45% used in-shoe or no orthoses.
Ninety-five percent of children (40/42) had lower-limb surgical interventions before their gait analysis visit [Table 2]. With regard to foot interventions, 29 feet underwent Ponseti treatment for clubfoot deformity and 48 feet underwent operative intervention for clubfoot. Seven patients (12 feet) exhibited a CVT, of which six patients underwent corrective surgery. Nineteen percent of children (8/42) had incomplete surgical history due to adoption or otherwise lack of specific surgical history; however, all eight children were known to have had operative intervention for clubfoot. Other surgeries included hip relocation surgery in seven children, patellar reduction in one child, and femoral osteotomies in one child. One patient had hip dislocation that was not suitable for surgical treatment due to severe dysplastic changes of the acetabulum.
|Table 2: Operative procedure types and prevalence in arthrogryposis patients|
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| Radiographic Results|| |
Foot radiographic evaluations were available for 22 children (41 feet). In the midfoot, rocker bottom deformities were seen in five children (10 feet; 24.4%), three of which had clubfoot and two CVT presentations. One child with clubfoot presentation in the surgical group showed severe deformity of the talus bilaterally (avascular necrosis) with ankle and subtalar ankylosis. Loss of the medial longitudinal arch of the foot was seen in 19 feet (46.3%).
| Physical Examination Results|| |
Physical examination demonstrated hip, knee, and ankle stiffness, as well as a limitation in gross motor function [Table 3]. Youth with arthrogryposis had a significant reduction in hip abduction, knee extension, knee flexion, dorsiflexion, plantar flexion, and excessive forefoot adduction (all P < 0.0001) compared to TD youth.
|Table 3: Comparison of children with arthrogryposis and typically developing children for physical examination data|
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| Pedobarograph Results|| |
Foot pressure measurements [Table 4] demonstrated that the dynamic foot posture of children with arthrogryposis and clubfoot deformities deviates from TD children with decreased heel contact (P < 0.0001) and increased lateral (P = 0.00001) and medial (P < 0.001) midfoot pressures. Medial forefoot pressure was lower in TD children (P < 0.00001). CPPI demonstrated residual varus though significant variation was present (P < 0.00001). For children with arthrogryposis and CVT deformities, the main differences were found at the lateral (P < 0.01) and medial (P < 0.01) forefeet. CPPI demonstrated residual valgus with statistically significant variation (P = 0.04).
|Table 4: Comparison between children with arthrogryposis (club foot and congenital vertical tali) and typically developing children for data from dynamic foot pressure|
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| Kinetic Results|| |
Kinetic data demonstrated abnormal hip and ankle force and power generation [Table 5]. Hip abduction moment was lower in children with arthrogryposis (P = 0.0003). Ankle plantar flexion moment and power generation were low (P < 0.0001). Hip power generation was higher than normative values (P = 0.01).
|Table 5: Comparison of walking kinetics data in 34 children with arthrogryposis and typically developing children|
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| Kinematic Results|| |
Kinematic data demonstrate a slow, crouched gait pattern with stiffness at the hip, knee, and ankle [Table 6]. Compared to age-matched peers, children with arthrogryposis walk with a low speed (P < 0.0001), excessive hip flexion (P < 0.0001), excessive knee flexion (P < 0.0001), and limited ankle range of motion (P < 0.001).
|Table 6: Comparison of kinematic data between children with arthrogryposis (n=50) and typically developing children|
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| Multisegment Foot Kinematic Results|| |
Multisegment foot kinematic data demonstrate hindfoot plantar flexion stiffness, hindfoot varus, and residual forefoot adduction [Table 7]. Hindfoot plantar flexion was limited at push off (P = 0.005) and was in varus (P = 0.035). Forefoot was in adduction compared to normative values (P = 0.0278).
|Table 7: Comparison between children with arthrogryposis with clubfoot (n=25) and typically developing children for data from a multisegment foot kinematic mode|
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Categorizing by age (<10 years or ≥10 years), [Table 8] reveals that some age-related differences may exist in children with arthrogryposis. The older group walked with higher speed (P = 0.00138), but they had more hip (P = 0.028) and knee (P = 0.0004) stiffness.
|Table 8: Comparison of physical examination, foot pressure, and kinematics between older and younger children with arthrogryposis|
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Separation by orthotic use [Table 9] demonstrated that children who use KAFOs had more severe contractures and lower gross motor function. GMFM was lowest in the group with KAFOs (P = 0.003; AFO vs. KAFO) and highest in the no-brace category (P = 0.0002; AFO vs. no orthotic). Hip abduction (P < 0.0001) and ankle dorsiflexion (P = 0.004; KAFO vs. no orthotic) were lower in the KAFO group compared to others.
|Table 9: Comparison of physical examination (degree), foot pressure (varus–valgus position), and kinematics between different types of orthoses|
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| Discussion|| |
Children with arthrogryposis frequently present with gait deviations and foot deformities. These gait deviations and foot deformities have been previously studied qualitatively, demonstrating stiffness at the hip, knee, and ankle with equinovarus compared to TD children.,,, During childhood, surgical treatment is often necessary to maintain ambulation or improve lower-limb function.,
The findings of the present study are consistent with the literature describing gait deviations in children with arthrogryposis.,,, Ambulation and physical examination measurements show stiff hips, knees, and ankles with a crouched gait pattern. The range of motion limitations has been shown in the literature for children with arthrogryposis.,, Stiffness in the ankles leads to low ankle power generation. In TD children, push off in walking is powered greatly by the ankles., In arthrogryposis, stiffness at the ankles minimizes this ability to propel at the ankles requiring propulsion to be powered by other parts of the body. Our study showed that hip power generation was highly likely to compensate for propulsion in walking. This is consistent with Eriksson et al.'s study showing that the hip muscles contribute more work in walking in children with arthrogryposis than in TD children as a result of low work production from the ankles.
This study revealed that children with AMC walk more slowly and have lower gross motor function than their TD peers. Eriksson et al. reported lower velocity in walking in children with arthrogryposis versus TD children. Those with more severe contractures, indicated by type of orthotic used, showed a less efficient gait, a slower walking velocity, and difficulties matching overall distance traveled with TD children. This is consistent with our findings of more stiffness and slower gait in those with KAFOs and AFOs. Studies looking at the effect of age and characteristics of arthrogryposis are limited. In this study, separation by age revealed a greater stiffness in the older age group.
Dynamic foot analysis findings demonstrated that foot posture deviated from normal with clubfoot deformities most commonly seen. Feet exhibited greater midfoot contact, suggesting some midfoot breakdown. Children with clubfoot deformities presented with residual equinovarus, reduced heel impulse, varus foot pressure distribution, and forefoot adduction. In contrast, children with arthrogryposis and CVT had normal heel impulse, valgus foot pressure, and reduced lateral forefoot pressure distribution.
Operative treatment has historically been suggested for clubfoot in children with arthrogryposis, but recently, as in children with idiopathic clubfoot, conservative management through the serial casting, specifically the Ponseti method for clubfoot deformities, has been suggested., Kowalczyk et al. showed that the Ponseti method improved clinical outcomes in arthrogrypotic clubfeet, reduced invasiveness of revisions, and shortened overall time of anesthesia and surgery. Our study demonstrated greater residual equinus and forefoot adduction, resulting in reduced heel contact in the group treated conservatively, but similar functional outcome with similar ankle power generation as compared to feet treated operatively. Mater et al. did a long-term follow-up study on clubfoot in arthrogryposis and showed that recurrence could be minimized in more cases if bracing is done as recommended., Further studies are needed to clarify the benefits of conservative treatment, including potential improvements in motion due to lack of surgical scarring. Koureas et al. reviewed radiographs of 1120 feet that had been conservatively treated for a clubfoot deformity and found 36 feet (3.2%) that developed a rocker bottom deformity. The incidence of rocker bottom deformity in our study was higher (24.4%) when compared with previous studies in clubfeet, which could be related to a persistence of a rigid equinocavovarus deformity. Van Bosse et al. demonstrated better outcomes with an initial percutaneous Achilles tenotomy before casting (modified Ponseti technique) compared to the original Ponseti technique in children with arthrogryposis.
The limitations of this study include a high incidence of surgical interventions prior to gait analysis. In children with arthrogryposis, surgical intervention is often performed prior to ambulation. Other limitations include variations in the number of children who performed a full gait analysis, resulting in less data for some of the analyses. This limited the categories that could be studied. This study was also limited by its cross-sectional nature. Ideally, a prospective, longitudinal study would provide a better indicator of age-related trends.
| Conclusion|| |
Children with arthrogryposis showed foot and gait deviations. Foot pressure measurements and radiographs showed midfoot breakdown. Residual equinovarus of the foot, as well as forefoot adduction, shown through foot pressure and multisegment foot kinematics, suggested recurrence of clubfoot deformities. Functional limitations were seen in low gait velocity, limitation in gross motor function, and low ankle force power generation. Hips, knees, and ankles demonstrated stiffness during gait in children with arthrogryposis, resulting in a crouched gait pattern.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Hall JG. Arthrogryposis multiplex congenita: Etiology, genetics, classification, diagnostic approach, and general aspects. J Pediatr Orthop B 1997;6:159-66.
Darin N, Kimber E, Kroksmark AK, Tulinius M. Multiple congenital contractures: Birth prevalence, etiology, and outcome. J Pediatr 2002;140:61-7.
Hall JG. Arthrogryposis (multiple congenital contractures): Diagnostic approach to etiology, classification, genetics, and general principles. Eur J Med Genet 2014;57:464-72.
Szöke G, Staheli LT, Jaffe K, Hall JG. Medial-approach open reduction of hip dislocation in amyoplasia-type arthrogryposis. J Pediatr Orthop 1996;16:127-30.
Kroksmark AK, Kimber E, Jerre R, Beckung E, Tulinius M. Muscle involvement and motor function in amyoplasia. Am J Med Genet A 2006;140:1757-67.
Sells JM, Jaffe KM, Hall JG. Amyoplasia, the most common type of arthrogryposis: The potential for good outcome. Pediatrics 1996;97:225-31.
Dillon ER, Bjornson KF, Jaffe KM, Hall JG, Song K. Ambulatory activity in youth with arthrogryposis: A cohort study. J Pediatr Orthop 2009;29:214-7.
Hoffer MM, Swank S, Eastman F, Clark D, Teitge R. Ambulation in severe arthrogryposis. J Pediatr Orthop 1983;3:293-6.
Böhm H, Dussa CU, Multerer C, Döderlein L. Pathological trunk motion during walking in children with amyoplasia: Is it caused by muscular weakness or joint contractures? Res Dev Disabil 2013;34:4286-92.
Eriksson M, Bartonek Š, Pontén E, Gutierrez-Farewik EM. Gait dynamics in the wide spectrum of children with arthrogryposis: A descriptive study. BMC Musculoskelet Disord 2015;16:384.
Guidera KJ, Drennan JC. Foot and ankle deformities in arthrogryposis multiplex congenita. Clin Orthop Relat Res 1985; 194:93-8.
Chotigavanichaya C, Ariyawatkul T, Eamsobhana P, Kaewpornsawan K. Results of primary talectomy for clubfoot in infants and toddlers with arthrogryposis multiplex congenita. J Med Assoc Thai 2015;98 Suppl 8:S38-41.
Zimbler S, Craig CL. The arthrogrypotic foot plan of management and results of treatment. Foot Ankle 1983;3:211-9.
van Bosse HJ. Syndromic feet: Arthrogryposis and myelomeningocele. Foot Ankle Clin 2015;20:619-44.
Kowalczyk B, Felus J. Ponseti casting and Achilles release versus classic casting and soft tissue releases for the initial treatment of arthrogrypotic clubfeet. Foot Ankle Int 2015;36:1072-7.
Niki H, Staheli LT, Mosca VS. Management of clubfoot deformity in amyoplasia. J Pediatr Orthop 1997;17:803-7.
Matar HE, Beirne P, Garg N. The effectiveness of the Ponseti method for treating clubfoot associated with arthrogryposis: Up to 8 years follow-up. J Child Orthop 2016;10:15-8.
Nicomedez FP, Li YH, Leong JC. Tibiocalcaneal fusion after talectomy in arthrogrypotic patients. J Pediatr Orthop 2003;23:654-7.
Davis LA, Hatt WS. Congenital abnormalities of the feet. Radiology 1955;64:818-25.
Keim HA, Ritchie GW. Weight-bearing roentgenograms in the evaluation of foot deformities. Clin Orthop Relat Res 1970;70:133-6.
Sangeorzan BJ, Mosca V, Hansen ST Jr. Effect of calcaneal lengthening on relationships among the hindfoot, midfoot, and forefoot. Foot Ankle 1993;14:136-41.
Vanderwilde R, Staheli LT, Chew DE, Malagon V. Measurements on radiographs of the foot in normal infants and children. J Bone Joint Surg Am 1988;70:407-15.
Mosca VS. Calcaneal lengthening for valgus deformity of the hindfoot. Results in children who had severe, symptomatic flatfoot and skewfoot. J Bone Joint Surg Am 1995;77:500-12.
O'Halloran CP, Halanski MA, Nemeth BA, Zimmermann CC, Noonan KJ. Can radiographs predict outcome in patients with idiopathic clubfeet treated with the Ponseti method? J Pediatr Orthop 2015;35:734-8.
Steel MW 3rd, Johnson KA, DeWitz MA, Ilstrup DM. Radiographic measurements of the normal adult foot. Foot Ankle 1980;1:151-8.
Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry. Philadelphia, PA: F.A. Davis Company; 2016.
Kendall FP, McCreary EK, Provance PG, et al.
Muscles: Testing and Function, with Posture and Pain. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
Harvey AR, Morris ME, Graham HK, Wolfe R, Baker R. Reliability of the functional mobility scale for children with cerebral palsy. Phys Occup Ther Pediatr 2010;30:139-49.
Damiano DL, Abel MF. Relation of gait analysis to gross motor function in cerebral palsy. Dev Med Child Neurol 1996;38:389-96.
Ponseti IV. The Ponseti technique for correction of congenital clubfoot. J Bone Joint Surg Am 2002;84:1889-90.
Bevan WP, Hall JG, Bamshad M, Staheli LT, Jaffe KM, Song K, et al.
Arthrogryposis multiplex congenita (amyoplasia): An orthopaedic perspective. J Pediatr Orthop 2007;27:594-600.
Staheli LT, Hall JG, Jaffe KM, Paholke DO. Arthrogryposis: A Text Atlas. Cambridge, UK: Cambridge University Press 1998.
Yau PW, Chow W, Li YH, Leong JC. Twenty-year follow-up of hip problems in arthrogryposis multiplex congenita. J Pediatr Orthop 2002;22:359-63.
Carlson WO, Speck GJ, Vicari V, Wenger DR. Arthrogryposis multiplex congenita. A long-term follow-up study. Clin Orthop Relat Res 1985;194:115-23.
Bartonek A, Eriksson M, Gutierrez-Farewik EM. Effects of carbon fibre spring orthoses on gait in ambulatory children with motor disorders and plantarflexor weakness. Dev Med Child Neurol 2007;49:615-20.
Eriksson M, Gutierrez-Farewik EM, Broström E, Bartonek A. Gait in children with arthrogryposis multiplex congenita. J Child Orthop 2010;4:21-31.
Gutierrez EM, Bartonek A, Haglund-Akerlind Y, Saraste H. Kinetics of compensatory gait in persons with myelomeningocele. Gait Posture 2005;21:12-23.
Winter DA. Energy generation and absorption at the ankle and knee during fast, natural, and slow cadences. Clin Orthop Relat Res 1983;175:147-54.
Eriksson M, Villard L, Bartonek A. Walking, orthoses and physical effort in a Swedish population with arthrogryposis. J Child Orthop 2014;8:305-12.
Boehm S, Limpaphayom N, Alaee F, Sinclair MF, Dobbs MB. Early results of the ponseti method for the treatment of clubfoot in distal arthrogryposis. J Bone Joint Surg Am 2008;90:1501-7.
Morcuende JA, Dobbs MB, Frick SL. Results of the Ponseti method in patients with clubfoot associated with arthrogryposis. Iowa Orthop J 2008;28:22-6.
Koureas G, Rampal V, Mascard E, Seringe R, Wicart P. The incidence and treatment of rocker bottom deformity as a complication of the conservative treatment of idiopathic congenital clubfoot. J Bone Joint Surg Br 2008;90:57-60.
van Bosse HJ, Marangoz S, Lehman WB, Sala DA. Correction of arthrogrypotic clubfoot with a modified ponseti technique. Clin Orthop Relat Res 2009;467:1283-93.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9]