• BACKGROUND
    • Postoperative outcomes following cervical spondylotic myelopathy (CSM) are excellent overall, but there are few prospective studies using patient-reported outcome measures that have explored how long improvement can be expected after surgery. The aim of this prospective study was to investigate from when and until when symptoms improve after open-door laminoplasty in patients with CSM and the factors that affect surgical outcomes.
  • METHODS
    • The subjects were 115 CSM patients who underwent laminoplasty. The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) was used for longitudinal evaluation, and surveys on cervical spine function, upper extremity function, lower extremity function, bladder function, and quality of life were conducted before surgery and at 3, 6, 12, 18, and 24 months after surgery. The patients were classified into 'effective' and 'ineffective' groups based on the points obtained for each domain, and the factors affecting the outcome of surgery were examined by multivariate analysis.
  • RESULTS
    • JOACMEQ scores improved significantly at 3 months postoperatively compared to preoperatively for all four domains except cervical spine function, but there was no significant improvement after 3 months postoperatively. Multivariate analysis showed that the preoperative score (cervical spine function and upper extremity function) and the points obtained at 3 months postoperatively (upper and lower extremity function, bladder function, and quality of life) were the factors associated with membership of the effective group at 24 months postoperatively.
  • CONCLUSIONS
    • Although upper and lower extremity function, bladder function, and quality of life domains improved in the relatively early postoperative period, improvement after 3 months postoperatively was limited. The results suggest that the preoperative score and the superiority of the improvement obtained up to 3 months after surgery may be indicators of postoperative outcomes, and this may provide new insights into the selection of surgical indications and patient explanations.