Arthrogryposis multiplex congenita (AMC) is a nonprogressive congenital neuromuscular syndrome that can be diagnosed at birth by the common phenotypic characteristics of joint contractures in 2 or more body areas, muscle weakness, and fibrosis.1,2 The cause of AMC is multifactorial. Some forms, such as distal arthrogryposis (types I and II), are genetically transmitted, whereas amyoplasia, the most common type of arthrogryposis, occurs sporadically.2 Fetal akinesia is a frequent finding in the development of most types of arthrogryposis, causing muscle mass of the limbs to be diminished and replaced by fibrous tissue.1–3 Hypotheses about conditions related to fetal akinesia include anterior horn cell dysfunction, neural tube defects, prenatal viral infection, vascular compromise between mother and fetus, uterine fibroid tumors, a septum in the uterus, oligohydramnios, various teratogens, and fetal hyperthermia.1,3,4 Although no definitive laboratory studies can be used to diagnose AMC prenatally, if a physician or parent is concerned about decreased fetal movements, a detailed level II ultrasound can be helpful to identify anomalies.1 Babies born with multiple congenital contractures often require further diagnostic testing and consultation with a geneticist, although amyoplasia is relatively easy to recognize at birth and may not require detailed diagnostic work-up.2 The estimated occurrence rate of AMC is 1 in every 3000 to 6000 live births, with equal sex distribution, and breech presentation in nearly one-third of the infants.1,3,4
Involved joints have limited range of motion (ROM) with a firm, inelastic end point and a lack of normal skin creases. Extremities of individuals with AMC are thin with a fusiform appearance.2,3,5 Sensation is normal, but deep tendon reflexes often are diminished or absent.2,3,5 Many areas may be severely affected in children with AMC including the foot, knee, hip, wrist, and elbow.1 The upper limbs tend to present with adducted, internally rotated shoulders, extended or flexed elbows with pronated forearms, flexed wrists with ulnar deviation and fingers that are partially but rigidly flexed, and adducted thumbs.1,4,5 Infants who present with relatively extended elbows often have adequate triceps strength in small ranges.1,4,5 If passive elbow flexion is possible, strength in the biceps and brachialis muscles is usually a grade of poor or less.4,5 The infants' lower limbs demonstrate variable positioning of the hips and knees; some have flexed and dislocated hips and extended knees, or in other infants abducted and externally rotated hips with flexed knees.1,5 Children with either presentation have clubfoot.1,5,6 Hip dislocation is present in 15% to 30% of infants, congenital knee dislocation may be present, and scoliosis develops in 30% to 67% during childhood with curves often progressing 6.5° per year.2,6
Amyoplasia, the most common form of AMC, occurs in more than one-third of all cases. Amyoplasia presents with symmetrical contractures in 85% of the children, typically affecting all extremities.1,2,7 Associated anomalies include hemangiomas on the face (84%), scoliosis (30%), plagiocephaly (29%), and torticollis (13%).1,5,6 A small percentage of children also have genital abnormalities, congenital hernias, marks consistent with cord wrapping or amniotic bands, congenital heart disease, and respiratory problems.1,4
Of children with AMC, 87% will undergo orthopedic surgery as they grow.1 Children average 5.7 procedures, most involving the lower limbs.4 Bernstein2 recommends that distal lower extremity (LE) deformities be repaired before proximal deformities. Clubfoot, the most common foot deformity, is often resistant to serial casting.
Since 1996, the Ponseti method of treating clubfoot has gained popularity.7 The method involves manipulation, casting, and the use of a Mitchell ankle-foot orthosis (MD Orthopedics, Wayland, Iowa), with percutaneous surgery to lengthen the Achilles tendon when necessary. An additional surgical procedure may be indicated between 6 months and 1 year of age if satisfactory clinical deformity correction is not achieved following this method.8 This surgery usually involves extensive soft tissue release of the posterior, medial, and lateral structures of the foot, the correction being held for 6 weeks with wire fixation across the joints of the foot, along with casting.9
Surgery is also considered for the upper extremities (UEs) if both elbows are in fixed in extension. Surgical correction of 1 elbow is desirable so the hand can approach the hair, face, and mouth.10 An elbow extension release and transfer of the triceps or pectoralis major may achieve improved arm function; however, this may have minimal benefit because the muscles transferred may be weak. In a study of 114 children with AMC,9 few operations were done on the wrist and hand because the children acquired functional skills despite their deformities, often using atypical patterns.10
According to Sells,4 the vast majority of children with AMC older than 5 years are completely independent or require only intermittent assistance in activities of daily living (ADLs), and 66% are ambulatory. Others have found that 85% of children with AMC are ambulatory.2,4,6 Donohoe reports that infants with AMC usually begin to walk with assistance around 18 months and independently ambulate by the middle of their second year.1 However, in a study examining contractures as a predictor of ambulation, only 50% of children with AMC who had knee flexion contractures achieved community ambulation, and those with severe hip flexion contractures had even more difficulty achieving the ability to walk.2 In contrast, children with knee extension contractures might walk well but had difficulty sitting and rising from a chair.2
Long-term functional outcomes for children with AMC are related to family support, patient personality, education, and early efforts to foster independence, with less correlation between physical deformities and function than might be expected.2 Many children with AMC are bright, motivated, and able to participate in regular classrooms at their appropriate grade level.1,4 Most will be able to have families, hold jobs, and have a normal life expectancy.11
Long-term sequelae associated with AMC can be very disabling.1 Those who required assistance with ADLs, ambulation, and mobility during their school-age years will probably continue to require assistance throughout their lifetime, only achieving a degree of independence through the use of adaptive equipment.12 Critical to those with AMC and their families is the need for education about the increased possibility of degenerative changes that can cause back and neck pain, osteoarthritis in weight-bearing joints, overuse syndromes, and secondary muscle weakness with decreased endurance, which may result in wheelchair use for long-distance mobility.1,2,12
Children with amyoplasia present their maximum deformity at birth.5 Early and ongoing treatment recommendations to increase ROM and to obtain a functional position of the joints include a combination of the remediation strategies—passive stretching, active ROM exercises, positioning activities, serial casting, and orthopedic treatments including intermittent serial manipulation and soft-tissue releases.1,6,7 Sells4 noted that 94% of children with AMC had physical therapy (PT) and 79% had occupational therapy (OT). Literature about AMC has suggested that PT and OT need to focus on strengthening postural muscles and attaining key functional motor skills to maximize mobility for age-appropriate activities.1 However, if a child does not have adequate strength to manipulate objects for play, self-care, writing, and eating, even when ROM is improved, the child would then require compensatory intervention strategies such as orthotics, splints, or adaptive equipment to assist in accomplishing these tasks.1,2 Formal assessment of an infant with AMC should begin as soon as possible after birth through documentation of (1) passive ROM, (2) strength of muscles through movement observation with palpation of muscle contractions, and (3) functional mobility and motor development using tests such as the Alberta Infant Motor Scale, the Bayley Scales of Infant Development III, or the Peabody Developmental Motor Scales, 2nd edition (PDMS-2).6,13–15 Studies outlining the appropriate frequency and timing of interventions for children with AMC are limited. Further evidence is needed to assist therapists in designing a plan of care with the appropriate intervention dosage. The purpose of this case report was to document the frequency and timing of interventions for an infant with AMC following a clinical decision-making process using the International Classification of Functioning, Disability and Health (ICF) model16 and the Guide to Physical Therapist Practice.17 Second, the purpose was to evaluate the child's outcomes with respect to participation, activity, and impairments of body structures and functions, including ROM.
DESCRIPTION OF THE CASE
History and Examination
The focus of this case report is an infant with amyoplasia (Figure 1). He was referred for OT and PT by his pediatrician and initially examined by a physical therapist at 11 days after birth. He was then followed in a hospital PT department until he was 9 months old. He had been managed in the neonatal intensive care unit for 1 week due to initial cardiac instability, during which time an occupational therapist fabricated splints for his wrists and hands due to ROM limitations associated with his AMC. He had an appointment with the pediatric orthopedist the following week to assess his severe bilateral clubfeet. During the initial interview with the physical therapist, with the infant's father holding him, the infant became upset and cried whenever he was moved, and his mother also became tearful.
- Musculoskeletal: The infant preferred to keep his head turned to the right in all positions, holding his head up for 1 second, then letting it tilt to the left or forward. His UE posture was with his arms at his sides, in a position of shoulder internal rotation, forearm pronation, and wrist/finger flexion. His LE posture included slight hip and knee flexion with his feet in severe clubfoot deformity.
- Neuromuscular: His only active movements were shoulder internal rotation and kicking with slight hip and knee flexion, observed when he became upset. Muscle tone, screened by resistance to passive movement, was within normal limits in the available range of his joints.
- Cardiopulmonary: His pulse (100 beats per minute) and respiration (30 breaths per minute) were within normal limits for an infant younger than 1 year, despite early concerns.18 His pediatrician had no further concern about his cardiopulmonary status.
- Integumentary: He did not have any skin redness/breakdown but would require monitoring of areas where his splints were applied and his joints were contracted.
- Cognition/pain: He cried when he was moved, placed on his stomach, and when his splints were donned and doffed.
- Other (plagiocephaly): His cranium was flatter on the right posterior lateral side.
On the basis of the history and systems review, this infant needed further examination of the musculoskeletal and neuromuscular systems, as well as pain responses. In addition, further examination of his hip status was required as hip dislocation is present in 15% to 30% of infants with AMC.2,6 Using the ICF model, tests and measures were chosen in the areas of participation, activity, and impairments of body structure and function.16
Tests and Measures
- The Patient Specific Functional Scale (PSFS) is a self-reported, patient-specific measure, designed to assess functional change in areas of interest, which can provide a picture of the patient's participation. For individuals with musculoskeletal disorders, excellent reliability (r = 0.92), poor to good validity (r = 0.73-0.83), and good sensitivity to change (r = 0.79-0.83) have been reported.19 Patients (or parents) are asked to identify up to 3 important activities that are difficult or unable to be accomplished, and the activities are scored from 0 to 10 (0 = inability, 10 = expected level). The PSFS was not scored at the initial visit, but it was scored at 3 and 9 months. At 3 months, the 3 activities identified and scored by the infant's parents were (1) bend his elbows, (score of 2), (2) reach up (score of 4), and (3) hold objects (score of 7).
- The Peabody Developmental Motor Scales, 2nd edition (PDMS-2) were used to measure his functional movement and activity. The PDMS-2 is a motor assessment with scales for gross and fine motor skills for children from birth to 71 months. The scales have good test-retest reliability (ICC = 0.88-1.00), excellent validity (r = 0.97), and sensitivity to change is 1.6 to 2.1.14,15 His standard score was 9 in locomotion and stationary skills.
- Prone tolerance was measured in seconds to determine change over a period of time. His initial time score was 0 seconds because he immediately became upset when placed in prone.
- Passive ROM was measured with goniometry using the Norkin method.20 Goniometric measurement has good to excellent reliability, fair to excellent intrarater and interrater reliability, good concurrent validity (ICC ≥ 0.85),20,21 and high correlation with radiographs.20,22 Significant limitations were found in UE and LE joints and the cervical spine (see Table 1). Hip dysplasia is suspected if at least a 5° to 10° limitation or asymmetry in passive hip abduction with the hip flexed to 90°; an asymmetric thigh or buttock crease, an apparent or true short leg, or a positive Ortolani or Barlow sign is present.23 This infant's right hip abduction was 45° and his left was 20°, indicating both limitation and asymmetry. This concern was communicated to his orthopedic surgeon.
- The Face, Legs, Activity, Cry, and Consolability (FLACC) Pain Scale is used to measure pain in preverbal children aged 2 months to 4 years, as well as older nonverbal children.24–26 The FLACC 5-item (face, legs, activity, cry, and consolability), 3-point scale (0 = content/relaxed and 2 = crying/kicking) has good reliability (r = 0.5-0.8) and validity.26 Although designed for children beginning at 2 months of age, the FLACC Pain Scale was used for this infant at 11 days due to a lack of other pain scales for very young infants. The FLACC measure was 10 during passive ROM and decreased to 0 after 4 to 5 minutes of inactivity (see Table 1).
The ICF model was used to guide the evaluation of this infant based on data gathered during the history and examination. The ICF includes consideration of participation restrictions, which for this young infant manifests as difficulty interacting with his parents and the environment in a manner typical of an infant at his age. These participation restrictions were associated with activity limitations that included difficulty with the positions required for visually interacting with his parents, decreased comfort with prone positioning and position changes for bathing and dressing, along with limited ability to move and hold his parents' fingers. Contributing impairments of body structures and functions included decreased passive ROM, asymmetry, and pain. He may also have had decreased strength, but this was not confirmed objectively (Figure 2). The dynamic evaluation process leads to goals that would reflect desired change and clinical judgments about areas of concern that could be addressed by PT interventions.
Despite the fact that this infant began PT very early, he was likely be less physically active than his peers, but he was expected to walk independently.5,27 Gross motor skills acquisition would likely not follow the typical developmental trajectory. Because he had minimal knee flexion contractures, evidence supports the expectation that he should walk with assistance around 18 months of age, ambulate independently by 2½ years of age, and in the community by the age of 5 years.1,4,5 Ambulation status depended upon whether his hip flexion contractures, which could make walking more difficult for him, were decreased.2 He had elbow extension contractures with no observable active elbow flexion and would possibly require a muscle transfer to allow active flexion at least 1 elbow for play and self-care.1,4 In addition, he was likely to require 1 or more surgeries on his feet and/or ankles to improve alignment and function.2 At this time of our initial evaluation he did not demonstrate a scoliosis, but that was a future possibility.2 On the basis of the typical profile of children with AMC, he was expected to be a bright, motivated child with normal scholastic achievement. With his family support, he was expected to have a good overall prognosis for future independent function including holding a job and having a family, with normal life expectancy.6,28 However, as an adult, he may have increased pain and weakness with age. Although expected to remain ambulatory as an adult, he may choose to use a wheelchair at times for endurance activities.1,12
The parents' main concerns at the initial visit were about their child's contractures in his wrists and his severe clubfoot position, but they were also aware that he did not have full ROM in his shoulders, elbows, hips, and knees. Their immediate goals were for his wrists and ankles to get “stretched out” so he would be “more normal,” which included reaching for and grasping toys, holding his bottle, and bringing his hands to his mouth. They also expressed hope that in the future he would be able to stand and walk. Short-term goals for this infant were developed in collaboration with his parents for a period that covered his first 3 months. These goals included objective, PT-specific criteria that were components of the functional goals. Functional and measurable long-term goals for a 9-month period were also developed with his family, most of which were directly related to achievement of short-term goals (see Table 2).
Description of Intervention
The infant began PT at 11 days of age. He was initially seen by a physical therapist weekly, which was decreased to every other week when the occupational therapist began treatment 3 weeks later. At that point, PT and OT alternated treatment sessions each week. Table 3 includes a detailed description of the frequency and duration of procedural interventions with progression of these activities. A different occupational therapist had fabricated his static positioning wrist and elbow splints in the neonatal intensive care unit. At his initial PT and OT visits, his parents were taught a home program of daily activities for remediation and compensation—(1) stretching activities for each contracted joint at 2 repetitions of 30 seconds each for each joint following bath time when he was more relaxed or when they were giving him a bottle, which helped to soothe him, (2) stretching of his neck in bilateral lateral flexion and left rotation through positioning and holding, (3) positioning toys and parent faces so he would turn his head to look to the left, (4) applying splints to his wrists during naptimes and at bedtime, (5) positioning prone across his parents' legs, and (6) carrying him in the prone extension position or emphasizing prone extension while sitting and leaning forward at the edge of his parents' knees. His parents were also educated about the possibility of scoliosis developing due to asymmetrical and decreased muscle strength, and that his spine should be assessed regularly. Although most curves are resistant to bracing, it may be used to delay surgery.1,2 At each regularly scheduled PT visit, the following activities occurred, with flexibility in time allotted based on the infant's tolerance—(1) reassessment of joint range, (2) stretching of neck, and UE and LE joints not casted, (3) age appropriate strengthening activities for neck flexion, lateral flexion, rotation, and extension in supine, prone, and sitting, (4) child-focused encouragement of gross motor development with accommodations for casts for the first 6 months, and (5) reassessment and updating of his home program with activities reviewed in the PT session.
Occupational therapy sessions included reassessing ROM, stretching the UEs, age appropriate UE strengthening with facilitation of manipulative arm and hand skills, monitoring his splints, and ongoing family education. New wrist and elbow positioning splints were made by another occupational therapist as his ROM improved.
Beginning at 2 weeks of age the infant was assessed by the pediatric orthopedist who began a serial casting program for his clubfoot deformity, using the Ponseti method to manage his clubfoot.7 At 3 months of age, the infant had bilateral percutaneous Achilles tenotomy surgery followed by a continuation of the long leg casts (Figure 3) until he was 6 months old when he began wearing the Mitchell AFO, 22 hours per day. The infant did not achieve an adequate correction of his clubfoot and had a progressive decrease in ankle ROM from 6 to 9 months of age. He was scheduled for bilateral posterior medial soft tissue releases with Achilles lengthening surgery at 10½ months of age.
The typical course of PT and OT for an infant with arthrogryposis is to receive direct intervention on a regular basis until he has achieved the maximum available ROM for all his joints, is as independent as possible, and has the necessary equipment for age appropriate access to his environment. He may continue after that time to receive PT and OT on a consultative basis to assess changes in his needs, address the appropriate interventions, and make recommendations as indicated.
Description of Outcomes
The infant was 9 months old at the time of the final data collection for this case report (Table 1), although he continued with PT and OT. The PSFS was not scored at the initial examination, but between 3 months and 9 months of age his total score improved 2.34 points. The minimal clinically important difference for the PSFS is 2 points.19 Gross motor skills decreased on the PDMS-2 from a standard score of 9 in locomotion and stationary skills at 11 days of age to 3 in locomotion and 8 in stationary skills at 9 months of age. Since standard scores allow a comparison across subtests, a score of 9 in both locomotion and stationary skills indicated that he scored equally on both measures at a young age.29 With increasing age his standard score in the locomotion subtest decreased to 3, and stationary skills decreased slightly to 8; locomotion became a relative weakness and was classified as very poor, whereas stationary skills were still considered average.29 The decline in PDMS-2 standard scores may be related to a floor effect because the test is designed for children who are typically developing beginning at birth. At 9 months of age, he was only able to roll to his sides as a means of locomotion, but not get into hands and knees, although in stationary skills he was able to sit without propping for at least several minutes. His prone tolerance improved from 0 seconds to at least 30 seconds, and he became comfortable when placed in prone, even attempting to roll to prone. He made substantial gains in bilateral shoulder flexion and abduction, elbow flexion, wrist extension, knee and ankle ROM; however, his ROM limitations continued to affect his motor skill acquisition. Hip abduction with hip flexion ROM was symmetrical, appropriate for a 9-month old, decreasing the clinical probability of hip dysplasia to a minimal level.30 He achieved full left lateral cervical flexion and increased 10° in left cervical rotation, achieving midline head posturing in all positions. Detailed changes in ROM are outlined in Table 1. He demonstrated positive change on the FLACC Pain Scale scores during passive joint ROM from 10/10 to 1/10 and no longer needed to be fed a bottle to soothe him during stretching.
During this 9-month period, the infant showed improvements in all components of the ICF, including positive change in several impairments of body structures and function noted above, as well as in participation and activity (see Table 2). Not all short- and long-term goals were met, but he demonstrated improvement on components of many goals. At 9 months of age (Figure 4), he was very visually and socially interactive with his parents, holding their fingers, as well as reaching for toys and grasping them, even with his wrists in a position of flexion. He was not able to bring his hands to his mouth due to his lack of active elbow flexion; however, he was able to bring his hands together at midline to play with toys and transfer them from hand to hand. His parents were pleased that he improved in his reaching and grasping but hoped that he would learn to hold his bottle and bring his hands to his mouth.
This case report provides information about timing and specific interventions for a young infant with AMC. The framework for this case used a clinical reasoning process supported by the ICF, using the patient management process described in the Guide to Physical Therapist Practice.16,17
At 9 months of age, many of this infant's impairments of body structure and function, functional activity limitations and participation restrictions improved. The program of stretching, muscle strengthening, facilitation of motor skills, orthopedic intervention, and parent education may have contributed to this infant's progress. He appears to be on the path to becoming ambulatory. However, locomotion skills measured by the PDMS-2 declined relative to his age. This was not unexpected, given the typical age of walking for a child with AMC is 2½ times that of an infant developing typically.4 He also has good family support, an engaging personality, and his parents have nurtured his independence as much as possible within his limitations to improve his functional outcome.
Using the clinical reasoning model depicted in Figure 2, the physical therapist, occupational therapist, and orthopedist prioritized their interventions to address impairments of body structure and function that could be remediated. Interventions included primary efforts focused on decreasing ROM limitations, improving functional strength and symmetry, and decreasing apparent pain that limited the infant's ability to participate in daily routines and play. Because many impairments of body structure and functions in individuals with AMC cannot be fully remediated, compensations were implemented including splinting to maintain range and modifications of positions and toys to maximize function. His parents were educated about these adaptations as well as prevention of secondary impairments, such as scoliosis.
One exception to his overall ROM gain was limited change in active elbow flexion. A dynamic splint that would assist in gaining more improvement in elbow flexion range may have been beneficial but could not be found for such a small infant. He may have surgery to gain elbow flexion range and possible tendon transfers to gain active elbow flexion in the future.
This infant's foot and ankle position improved markedly, but he will require further orthopedic surgery to improve alignment, with a long-term goal of standing and walking. It became clear after the serial casting was completed at 6 months of age that the Mitchell shoes with a bar did not control the ROM of his foot and ankle, although compliance with this device was not objectively assessed. An ankle orthotic or splint may have prevented the degree of decline in ankle ROM over the period from 6 to 9 months of age. He was scheduled for bilateral posterior medial releases with Achilles lengthening surgery at 10½ months of age, to potentially improve his foot and ankle alignment for standing and walking, although Bernstein2 describes a 73% recurrence rate in clubfoot contracture even with surgery; therefore, he may require more surgery in the future.
As this infant becomes older, his goals may change to ambulation and ADLs, which should be made easier by the improvements in ROM and functional strength achieved at an earlier age. Or, it may be necessary to teach him compensatory strategies or use assistive technology for activities in which he is limited by decreased strength and ROM, to promote independence.5,6 Understanding the long-term implications of the PT and OT activities in early years should help improve outcomes through the lifespan. The plan of care, including the frequency and timing of interventions, and the resultant changes in his participation, activity limitations, and impairments of body structures and functions have been documented in this case report.
Prospective intervention studies are needed to begin to establish efficacy for the components of the plan of care for this population. Future studies, exploring specific intervention strategies and intervention timing and dosage, will contribute to the body of knowledge for physical therapists treating children with AMC.
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