Hip Status and Long-term Functional Outcomes in Spina Bifida

The Etiology of Neuromuscular Hip Dysplasia and Implications for Management: A Narrative Review

This study summarizes the current knowledge of the etiology of hip dysplasia in children with neuromuscular disease and the implications for management. This article is based on a review of development of the hip joint from embryology through childhood growth. This knowledge is then applied to selective case reviews to show how the understanding of these developmental principles can be used to plan specific treatments. The development of the hip joint is controlled by genetic shape determination, but the final adult shape is heavily dependent on the mechanical environment experienced by the hip joint during growth and development. Children with neuromuscular conditions show a high incidence of coxa valga, hip dysplasia, and subluxation. The etiology of hip pathology is influenced by factors including functional status, muscular tone, motor control, child's age, and muscle strength. These factors in combination influence the development of high neck-shaft angle and acetabular dysplasia in many children. The hip joint reaction force (HJRF) direction and magnitude determine the location of the femoral head in the acetabulum, the acetabular development, and the shape of the femoral neck. The full range of motion is required to develop a round femoral head. Persistent abnormal direction and/or magnitude of HJRF related to the muscular tone can lead to a deformed femoral head and a dysplastic acetabulum. Predominating thigh position is the primary cause defining the direction of the HJRF, leading to subluxation in nonambulatory children. The magnitude and direction of the HJRF determine the acetabular shape. The age of the child when these pathomechanics occur acts as a factor increasing the risk of hip subluxation. Understanding the risk factors leading to hip pathology can help to define principles for the management of neurologic hip impairment. The type of neurologic impairment as defined by functional severity assessed by Gross Motor Function Classification System and muscle tone can help to predict the risk of hip joint deformity. A good understanding of the biomechanical mechanisms can be valuable for treatment planning.

Orthopaedic outcomes of prenatal versus postnatal repair of myelomeningocele

Myelomeningocele, characterized by extrusion of the spinal cord through a spinal canal defect, is the most common form of spina bifida, often resulting in lifelong disability and significant orthopaedic issues. A randomized controlled trial (RCT) has shown the efficacy of prenatal repair in decreasing the need for shunting and improving motor outcomes. However, no studies have evaluated the effects of prenatal repair on orthopaedic outcomes. The purpose of this study was to determine the rates of orthopaedic conditions in patients with prenatal and postnatal repair of myelomeningocele and compare the rates of treatment required. This study analyzes the relevant outcomes from a prospective RCT (Management of Myelomeningocele Study). Eligible women were randomized to prenatal or postnatal repair, and patients were evaluated prospectively. Outcomes of interest included rates of scoliosis, kyphosis, hip abnormality, clubfoot, tibial torsion, and leg length discrepancy (LLD) at 12 and 30 months. The need for orthopaedic intervention at the same time points was also evaluated. Statistical analyses included descriptive statistics and univariate analyses. Data for the full cohort of 183 patients were analyzed (91 prenatal, 92 postnatal). There were no differences in rates of scoliosis, kyphosis, hip abnormality, clubfoot or tibial torsion between patients treated with prenatal or postnatal repair. The rate of LLD was lower in the prenatal repair group at 12 and 30 months (7 vs. 16% at 30 months, P = 0.047). The rates of patients requiring casting or bracing were significantly lower in patients treated with prenatal repair at 12 and 30 months (78 vs. 90% at 30 months, P = 0.036). Patients treated with prenatal myelomeningocele repair may develop milder forms of orthopaedic conditions and may not require extensive orthopaedic management.

Adults with spina bifida: ambulatory performance and cognitive capacity in relation to muscle function

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

Describe and compare ambulatory performance and cognitive capacity in relation to muscle function in an adult cohort with spina bifida. Also, explore factors associated with ambulation in participants with muscle function level 3.

SETTING

Specialist clinic for adults with spinal cord disorders in Stockholm, Sweden.

METHODS

A total regional cohort of adults (n = 219) with spina bifida was invited, 196 (104 women, mean age 35 years, SD 13 years) participated. Mode of mobility, cognitive capacity and muscle function were investigated. For participants with muscle function level 3, factors associated with ambulation were investigated using multivariate logistic regression analysis.

RESULTS

In all, 84 participants (42%) were community ambulators, 22 (12%) household ambulators and 90 (46%) wheelchair users. There was a linear association between the lower degree of muscle function and scoliosis (P < 0.001). Mode of mobility varied despite similar muscle prerequisites in participants with muscle function level 3 (n = 58). Factors associated with ambulation in participants with muscle function level 3 were the absence of scoliosis, lower BMI and higher cognitive capacity.

CONCLUSIONS

Cognitive capacity and mode of mobility varied widely across the cohort. However, in participants with muscle function level 3, despite similar muscular prerequisites, a large variation in the mode of mobility was found, suggesting that other factors were involved. It is important to prevent scoliosis, support a healthy lifestyle, as well as offer cognitive screening and support to promote ambulatory function and optimise independence in the everyday lives of adults with spina bifida.

International multidisciplinary collaboration toward an annotated definition of arthrogryposis multiplex congenita

Arthrogryposis multiplex congenita (AMC) has been described and defined in thousands of articles, but the terminology used has been inconsistent in clinical and research communities. A definition of AMC was recently developed using a modified Delphi consensus method involving 25 experts in the field of AMC from 8 countries. Participants included health care professionals, researchers, and individuals with AMC. An annotation of the definition provides more in-depth explanations of the different sentences of the AMC definition and is useful to complement the proposed definition. The aim of this study was to provide an annotation of the proposed consensus-based AMC definition. For the annotation process, 17 experts in AMC representing 10 disciplines across 7 countries participated. A paragraph was developed for each sentence of the definition using an iterative process involving multiple authors with varied and complementary expertise, ensuring all points of view were taken into consideration. The annotated definition provides an overview of the different topics related to AMC and is intended for all stakeholders, including youth and adults with AMC, their families, and clinicians and researchers, with the hopes of unifying the understanding of AMC in the international community.