Enter the pre- and post-operative JOA scores to calculate the percentage of neurological recovery achieved through surgical intervention.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Postoperative assessment of patients undergoing decompressive spine surgery (e.g., laminectomy/laminoplasty, ACDF) for Cervical Spondylotic Myelopathy (CSM).
Quantifying the true clinical benefit of the surgery relative to the patient's maximum potential improvement.
Section 2
Formula & Logic
Why Absolute Difference Fails
Simply subtracting the pre-op JOA score from the post-op JOA score is flawed. A patient improving from 15 to 17 (a 2-point gain) represents a 100% cure. A patient improving from 5 to 7 also has a 2-point gain, but still has severe myelopathy. The Hirabayashi calculation normalizes this by dividing the gain by the total possible room for improvement.
Section 3
Evidence Appraisal
Primary Reference
Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament
