Correlates of functional ankle instability in children and adolescents with Charcot-Marie-Tooth disease

BACKGROUND

Functional ankle instability (FAI) is commonly reported by children and adolescents with Charcot-Marie-Tooth disease (CMT), however,, the specific variables associated with FAI remain unknown. An improved understanding of these variables may suggest interventions to improve ankle stability and possibly prevent the long-term complications associated with ankle instability in this population. The aim of this study was to therefore investigate the relationship between FAI and other functional, structural, anthropometric and demographic characteristics in a cross sectional sample of children and adolescents with CMT.

METHODS

Thirty children and adolescents with CMT aged 7-18 years were recruited from the Peripheral Neuropathy Clinics of a large tertiary paediatric hospital. Measures of FAI were obtained using the Cumberland Ankle Instability Tool (CAIT). Demographic and anthropometric data was also collected. Other variables collected included foot structure (Foot Posture Index), ankle range of motion (weight bearing lunge) and functional parameters (balance, timed motor function and falls). Descriptive statistics were calculated to characterise the participants. Pearson's correlation coefficients were calculated to investigate the correlates of right and left FAI and demographic (age), anthropometric (height, weight, BMI), foot/ankle (foot structure and ankle flexibility) and functional parameters (balance task, timed motor function and falls frequency). Point biserial correlation was employed to correlate gender with right and left FAI.

RESULTS

All but one study participant (n = 29) reported moderate to severe bilateral FAI with females reporting significantly greater ankle instability than males. FAI was significantly associated with cavus foot structure (r = .69, P < .001), female gender (r = -.47, P < .001) and impaired balance (r = .50, P < .001).

CONCLUSIONS

This study confirms FAI is common in children and adolescents with CMT. An examination of the correlates of FAI suggests interventions, which target balance, and normalise foot structure should be explored to evaluate whether they might help to improve ankle stability in this population.

Systematic review of chronic ankle instability in children

Background

Chronic ankle instability (CAI) is a disabling condition often encountered after ankle injury. Three main components of CAI exist; perceived instability; mechanical instability (increased ankle ligament laxity); and recurrent sprain. Literature evaluating CAI has been heavily focused on adults, with little attention to CAI in children. Hence, the objective of this study was to systematically review the prevalence of CAI in children.

Methods

Studies were retrieved from major databases from earliest records to March 2013. References from identified articles were also examined. Studies involving participants with CAI, classified by authors as children, were considered for inclusion. Papers investigating traumatic instability or instability arising from fractures were excluded. Two independent examiners undertook all stages of screening, data extraction and methodological quality assessments. Screening discrepancies were resolved by reaching consensus.

Results

Following the removal of duplicates, 14,263 papers were screened for eligibility against inclusion and exclusion criteria. Nine full papers were included in the review. Symptoms of CAI evaluated included perceived and mechanical ankle instability along with recurrent ankle sprain. In children with a history of ankle sprain, perceived instability was reported in 23-71% whilst mechanical instability was found in 18-47% of children. A history of recurrent ankle sprain was found in 22% of children.

Conclusion

Due to the long-lasting impacts of CAI, future research into the measurement and incidence of ankle instability in children is recommended.

Measuring Ankle Instability in Pediatric Charcot-Marie-Tooth Disease

Children with Charcot-Marie-Tooth disease frequently suffer ankle sprain and experience chronic ankle instability; however, no pediatric self-reported measures of chronic ankle instability exist. The aim was to modify and validate the most reliable measure of chronic ankle instability in adults: the Cumberland Ankle Instability Tool. The Cumberland Ankle Instability Tool-Youth was tested for reliability, construct validity, and sensitivity to discriminate between 104 children aged 8 to 16 years: 31 children with Charcot-Marie-Tooth disease, 31 unaffected children with a history of ankle sprains, and 42 controls. Children with Charcot-Marie-Tooth disease had lower scores compared to unaffected children with a history of sprains (χ² = 15.10; P < .001) and controls (χ² = 33.69; P < .001). Scores moderately correlated to visual analog scale scores of ankle steadiness (r _s = 0.684; P < .001), and "good" test-retest reliability was identified (ICC_2,1 = 0.73). The Cumberland Ankle Instability Tool-Youth demonstrated excellent sensitivity and construct validity, identifying chronic ankle instability as a common problem for children with Charcot-Marie-Tooth disease.