Reliability and validity of the pediatric adaptation of the mJOA scale for evaluating cervical spine disorders.

Purpose: The study aimed to evaluate the validity and reliability of the pediatric adaptation of the Japanese Orthopedic Association (mJOA) scale in pediatric patients with various cervical spine pathologies.

Methods: Initial assessments were performed by a neurosurgeon, followed by an independent evaluation by a neurologist within 1-2 days to test inter-rater reliability. The same clinician assessed the same group of children using the adapted mJOA scale at different point in time (between 1 month and 1 year after the initial assessment) to test intra-rater reliability. For known-groups validity, the pediatric mJOA scale assessments were compared between two groups of pathologies with different prognosis. Concurrent validity was assessed against the McCormick scale, and convergent validity was tested by reassessing patients using the adult mJOA scale two or more years after the initial assessment by pediatric one.

Results: A cohort of 169 pediatric patients aged 6 months to 18 years (mean age: 10 ± 4.6 years) with various cervical spine pathologies was recruited. Pathologies included atlanto-axial rotatory fixation (AARF), Chiari type I anomaly, congenital cervical spine scoliosis, atlanto-axial dislocation (AAD) and instability (AAI), cervical spine stenosis and trauma, and congenital cervicothoracic dislocations. The majority of patients underwent cervical spine surgery and were followed up for an average of 6.9 ± 2.97 years. The pediatric mJOA scale demonstrated high inter-rater reliability (r = 0.99, p < 0.0001) and strong intra-rater reliability (r = 0.82, p < 0.0001). Significant differences in pediatric mJOA scores were observed between patients with expected-intact neurological status and those with expected-pathological neurological status (p < 0.0001). The pediatric mJOA scale showed a strong correlation with the McCormick grading system (r = 0.97, p < 0.001) and good correlation with the adult mJOA scale during long-term follow-up (r = 0.82, p < 0.0001).

Conclusions: The pediatric version of the mJOA scale is a reliable and valid tool for assessing pediatric patients with cervical spine disorders. Its high reliability and validity support its use in both clinical practice and research.