Reliability and Validity of the Thai Version of the Modified Japanese Orthopaedic Association Score (mJOA score)

Objective: To evaluate the reliability and validity of the Thai version of the modified Japanese Orthopaedic Association scale. Methods: Te modified Japanese Orthopaedic Association scale was translated into Tai language to create the Tai version of the Modified Japanese Orthopaedic Association (Tai-mJOA) scale. Translation was performed according to international standards using a forward-backward translation protocol. Translation was performed by 2 expert translators and 1 physician, and the final version was approved by an expert committee. Tai patients with cervical spondylosis with myelopathy were enrolled and evaluated using the Tai-mJOA scale, Nurick Grading, the Tai version of the Neck Disability Index (Tai-NDI), and the Tai version of the Short Form-36 (Tai-SF-36). Reliability and validity of the Tai-mJOA were assessed via comparison with the Nurick Grading and the Tai-NDI. Results: Ninety-two patients were included. Te most common compression level was C5-C6 vertebral disc. Cronbach’s alpha of the total Tai-mJOA showed excellent internal consistency (0.991). Te intraclass correlation coefficient (ICC) for test-retest reliability was 0.981 (95% confidence interval [CI]: 0.972-0.988). Regarding concurrent validity, the motor dysfunction score of the lower extremities and the total score of the Tai-mJOA were strongly correlated with Nurick Grading (r=0.825, r=0.712, respectively). Te total score of the Tai-mJOA was moderately correlated with the Tai-NDI (r=0.670). Conclusion: Te Tai-mJOA was found to be a valid and reliable tool for evaluating symptom severity in Tai patients with cervical spondylosis with myelopathy.