Patient perceived outcome after central corpectomy for cervical spondylotic myelopathy.

BACKGROUND: Patient perception of outcome after decompressive surgery for CSM is infrequently reported. We evaluated a simple, quantitative patient-reported assessment of outcome after CC for CSM by comparing it with the NGRR.
METHODS: In a prospective study between 1994 and 2004, patients who underwent CC for CSM were asked to quantify the outcome (relative to their preoperative status) on a scale of 0 to 100. Patient perceived outcome score was compared with the NGRR (preoperative grade - postoperative grade / preoperative grade x 100) at the same follow-up.
RESULTS: A total of 208 patients with a follow-up ranging from 6 to 72 months (mean, 16.3 months) were evaluated. There was a good positive correlation between PPOS and NGRR for the whole group (Pearson correlation coefficient, 0.62; P < .001), good-grade patients (preoperative Nurick grade of 1-3) (Pearson correlation coefficient, 0.52; P < .001), and poor-grade patients (Pearson correlation coefficient, 0.79; P < .001); the correlation was strongest in the poor-grade group of patients. kappa statistic revealed moderate agreement between the 2 scores in the whole group (kappa = 0.45), substantial agreement in the poor-grade patients (kappa = 0.61), and fair agreement in the good-grade patients (kappa = 0.34). In 28 of the 208 patients (13.5%), there was no agreement between the 2 scores with a significantly greater proportion (24/28), reporting an improvement in spite of no change in their Nurick grade (McNemar chi(2) test, P = .0002).
CONCLUSIONS: Although there was good agreement and a positive correlation between PPOS and NGRR, the disagreement in 13.5% of patients suggests that the 2 scores are evaluating some dissimilar functional domains; therefore, PPOS provides additional independent data in the assessment of the results of decompressive surgery for CSM. Patient-reported outcome should be included in reporting outcome of decompressive surgery for CSM.