arthrogryposis multiplex congenita ( amc ) is a multiple joint condition which affects both lower and upper extremities and thus affects ambulation . the objective of this study is to identify the most critical residual deformity that diminishes the ambulatory status . the mean age at first surgery was 4.1 years ( range 2 - 16 years ) . the mean length of followup was 44.0 months ( range 22 - 168 months ) . type of procedures and number of operations , residual deformity and walking ability were recorded . residual deformity including hip flexion contracture more than 30 , knee flexion contracture more than 30 , scoliosis , hip dysplasia or dislocation , knee extension contracture or recurvatum , active motion of hips and knees and upper limb involvement were evaluated . statistical analysis was done to evaluate factors that were statistically significant to affect walking ability in amc patients . at the latest followup , 31 patients were community ambulators , 3 patients were household ambulators , 3 patients were nonfunctional ambulatory , and 14 patients were nonambulatory . statistical analysis of all factors was done and the results were significant with a p < 0.037 in knee flexion contracture > 30 degrees with odds ratio of 4.58 . hip flexion contracture > 30 was a trend toward significant with a p value of 0.058 and odds ratio of 4.53 . multivariate analysis showed that knee flexion contracture was significant with 4.58 ( 95% ci 1.01 - 20.6 ) . amc is a rare disease that causes disability , requiring multiple surgeries to correct deformities . our study showed that residual knee flexion contracture was associated with nonambulatory status of patients with amc . arthrogryposis multiplex congenita ( amc ) is a rare , nonprogressive congenital disorder which is characterized by multiple joint contractures with normal sensation.12345 diagnosis of amc is usually based on physical examination with characteristic deformities of upper and lower extremities , limited range of motion , clubfoot or hip dislocation . there are 150 different disorders for syndromes that have joint contractures as a part of their manifestations ; amc is diagnosed by exclusion , and precise diagnosis is very important for the evaluation of results.6 the term  amyoplasia  refers to the most common arthrogrypotic syndrome , which includes multiple congenital contractures , typical and symmetrical positioning of the limbs and the replacement of muscles by fibrous and fatty tissues . it is sporadic , with an unknown hereditary pattern.7 the goal of treatment is to obtain the maximum possible function for each child by an early multidisciplinary approach.78 at present the goal of treatment is to improve ambulatory status of patients and patient self - care . amc patients have multiple problems which can be improved by surgical intervention but the most helpful procedures are still undefined . this study aims to find residual deformity that affects the ambulatory status of the patient . residual deformities that are risk factors in this study include hip flexion contracture more than 30 , knee flexion contracture more than 30 , knee extension deformity or recurvatum , severe scoliosis , upper extremity contracture or weakness and development dysplasia of the hip ( ddh ) or hip dislocation . we feel that our results will guide physicians in decision making regarding treatment to promote ambulation in amc patients . this study was designed as a retrospective study of amc patients at our institute from january 1995 to december 2010 . after approval from the ethics committee , chart review was conducted in accordance with the guidelines provided from our institutional review board . we reviewed all the medical records and included only those children with amc who had a mean followup of 44 months ( range 22 - 168 months ) . the inclusion criteria were amc patients who underwent surgical procedure or treatment for deformities or dislocations of the joints in the upper or lower limbs and patients or parents who agreed to participate . the study recruited 53 patients ; two of them were excluded because of incomplete medical data . we recorded the children 's potential to ambulate at the first visit and at each of the subsequent visits until the last followup . all clinical assessment was recorded and included age , sex , associated disease , and surgical procedure carried out . ambulatory status and residual deformities which include deformities in both upper and lower extremities , scoliosis , degrees of contracture at the hips and knees , active motion of hips and knees and the presence of ddh or hip dislocation were recorded from the clinical and physiotherapy notes . thirty three patients were in walking age and twenty patients were ambulatory at the start of treatment . walking age in this study was patient age more than 18 months . all the patients who were ambulatory at the start of treatment remained ambulatory at final followup . out of thirty one patients who were nonambulatory at the start of treatment , seventeen patients could ambulate at the final followup , fourteen patients were still nonambulatory . of the thirty one patients who were nonambulatory at the start of treatment , twenty one patients had hips and knee flexion contracture of more than 30 and after proximal femoral extension osteotomy and distal femoral extension osteotomy , seventeen patients who were corrected to less than 30 of hips and knee flexion contractures could walk . for the residual deformities , seven patients had hip flexion contracture more than 30 and nine patients had knee flexion contracture more than 30. forty seven patients were able to do active range of motion of hips and knees . there were 54 upper extremities procedures and 165 lower extremities procedures [ tables 2 and 3 ] . bilateral limb surgeries were considered as two procedures , even if they were done during the same anesthesia [ tables 2 and 3 ] . the final functional outcome was assessed using hoffer 's classification of walking status [ table 4].9 thirty one patients were community ambulatory who were able to walk with aids in the community and did not need a wheel chair , three patients were household ambulatory , able to walk with aids in the house and use a wheel chair in the community whereas three patients were nonfunctional ambulators using a wheel chair and capable of transfer while 14 patients were nonambulators and were not capable of transfer [ table 4 ] . location and type of operations for the upper limbs type of operations for the lower limbs characteristics of walking at latest followup at the last followup , 37 patients were ambulatory and 14 patients were nonwalkers . there was statistical significance with p value 0.037 for knee flexion contracture more than 30 with odds of 4.58 ( 95% ci 1.01 - 20.6 ) . hip flexion contracture more than 30 was a trend toward significant with a p value 0.058 and odds ratio of 4.53 . these children are best managed by multidisciplinary teams that include an experienced geneticist , an orthopedic surgeon , a physical therapist , and a pediatric physical therapist . it should be recognized that high percentage of these children might be able to achieve some measure of functional ambulatory potential , but many will lose ambutation as they get older . the need for surgery is high in these children , and often , several procedures will be necessary . a careful discussion of realistic goals with the parents is very important , as is the ongoing focus on skills necessary for promoting independence in adulthood . hoffer et al.9 reported functional ambulation in 22 out of 36 severely affected adolescents and young adults with arthrogryposis . many series have reported varying degrees of functional ambulation in 50 to 78% of patients.1011 sells et al.11 found that 85% of children with amyoplasia were ambulatory by the age of 5 . these children had an average of 5.7 orthopedic procedures along with multiple casting , splinting of limbs and regular physical and occupational therapy . ultimately they were able to participate in activities of daily living and attend school . based on our findings we strongly believe that children with arthrogryposis may have good potential for ambulation if their knee flexion contractures have been adequately and timely corrected . kroksmark et al . has reported a group of patients with amyoplasia that are indistinguishable in the newborn period and respond dramatically to physical therapy.12 all of these series suggest an optimistic childhood , with peak function occurring by the age of 10 years and some decline in ambulation into the adult years . despite these reports assessment for this potential can be difficult , with decisions of the extent and timing of surgery hanging in balance . future multicenter studies by exploring the effects and involvement of residual deformity which affect ambulation in this population are recommended . longer followup periods should be included to verify the extent to which ambulatory gains are maintained . knee involvement is commonly seen among children with arthrogryposis , with flexion contracture of the knee being the most frequent knee deformity . knee flexion contracture in the pediatric population is particularly debilitating as it adversely affects ambulation . treatment for knee flexion contracture requires numerous orthopedic procedures and extensive followup period . according to most authors , knee flexion contracture is more frequent and more difficult to treat with conservative methods than the knee extension contracture.1314 in the literature consensus is to perform early serial casting and physiotherapy , which sometimes is sufficient to correct contracture in flexion or extension . in cases of failure of conservative treatment surgery is recommended and includes procedures like by posterior capsulotomy in addition to soft - tissue release ( including hamstring tenotomy ) . del - bello and watts recommended performing a distal femoral extension osteotomy for flexion contracture as a safe procedure even for severe contractures.15 thomas et al . used femoral osteotomies in young patients because the walking improvement is large and quick ( 32 nonambulators became community or household ambulators in their series).13 brunner et al . used the ilizarov technique as an efficient tool for knee and foot deformity corrections ; however , he noted a high recurrence rate in children younger than 10 years of age.16 thomas et al . and hoffer et al . noted the importance of having a flexion contracture less than 20 degrees in order to walk independently.913 our results support this conclusion . murray and fixsen presented functional results of 22 patients with amyoplasia followed up over an average of 7 years . patients in this series were treated by initial physiotherapy and splintage , as well as repeated posterior release and bony procedures when necessary . they reported 14 community walkers in 22 patients.14 herzenberg et al . reported 10 patients with knee flexion contractures of various different etiologies , including 2 patients with arthrogryposis , treated with ilizarov external fixator . both became community ambulators at the latest followup.17 a study by van bosse et al.18 reported a high rate of improvement in ambulation in all seven children with arthrogryposis with knee flexion contracture after ilizarov correction at latest followup , including five who were initially nonambulatory . a recent report by fassier et al . indicated that among 11 children with arthrogryposis , 7 were independent ambulators at skeletal maturity.19 however , these children had normal knee mobility or a flexion contracture of less than 15 and most had mild involvement of the hips , spine , or upper extremities . we agree with these researchers that early aggressive management of children with severe arthrogryposis is justified and recommended . in our series hip flexion contracture we observed that community ambulators presented with less than 30 degrees of hip flexion contracture . hoffer et al . also noted that less than 30 of hip flexion contracture in their independently walking patients.9 staheli et al.420 and hoffer et al.9 have categorized children with ambulatory potential as having grade 4 or greater hip extensors ; hip flexion contracture less than 20 ; grade 4 quadriceps function ; grade 3 quadriceps function with knee flexion contracture less than 20 ; and good strength and sitting balance , with shoulder depressor function and only mild upper extremity abnormalities but many studies show progressive muscle activity improvement after the recovery of a passive range of motion in a useful arc . many studies showed that independent ambulators were able to perform an increase in strength during growth . the difficulty remaining in identifying prognosis factors is , as with the case of any rare diseases , the small number of patients available to generate data . in our series , poor prognostic factors for independent or community walkers were residual knee flexion contracture more than 30. hip flexion contracture is less likely to occur in isolation , but if greater than 30 , it may affect ambulation , and if greater than 45 , it will generally require release . often , the combination of hip flexion , external rotation , and abduction contractures are present.21 in these cases , the hip abductors may function as extensors and if the hip is left in external rotation , the hip can often be adducted to neutral and extend to less than 30 of contracture without soft tissue release while preserving good hip extensor strength for standing . a distal femoral osteotomy is necessary to bring the knee and foot into alignment for ambulation . reduction of hip dislocation is recommended for unilateral dislocation in all reports.2021 long term ambulatory status at skeletal maturity is not correlated with the severity of condition at birth.19 therefore , we believe that early aggressive management of children with severe arthrogryposis is warranted and justified . the ambulatory status in children with arthrogryposis is variable and our findings seem to indicate that although knee flexion contractures have an impact on ambulation , hip flexion contracture may also influence ambulation . our findings emphasize that residual knee flexion contracture affects the ambulatory status of children with arthrogryposis . surgical interventions for knee flexion contractures in this population is warranted and support a positive prognosis .