[The comparative study of effect of a modified open door laminoplasty using anchor method on axial symptoms and...

To evaluate the effect of a modified open door laminoplasty using anchor method on reducing the occurrence of axial symptoms and loss of cervical curvature.

From October 2004 to May 2007,56 patients with cervical spondylotic myelopathy underwent this procedure and been followed up (group A). Another 50 patients who underwent conventional unilaterally open-door laminoplasty served as control (group B). The operation time, blood loss, JOA scores and the incidence of newly developed or deteriorated axial symptoms were recorded. Preoperative and postoperative curvature angle which was presented on the tangent of posterior vertebral body margins of C2 and C7 in the cervical spine were measured on cervical radiographs.

The operative time was (116 +/- 27.9) min in group A and (120 +/- 18.9) min in group B,showing no statistically significant difference (P > 0.05). The operative blood loss was (148 +/- 68.3) ml in group A and (152 +/- 63.4) ml in group B (P > 0.05). According to JOA scores, the average recovery rates were (61.1 +/- 24.5)% in group A and(53.3 +/- 23.3)% in group B (P < 0.05). Postoperative development or deterioration of axial symptoms occurred in 41.1% of patients in group A and 76.0% of patients in group B,showing statistically significant difference (P < 0.05). There was no significant difference between preoperative (6.3 degrees +/- 5.1 degrees) and postoperative (6.6 degrees +/-4.5 degrees) cervical curvature angle in group A,whereas the mean value of postoperative angle(4.8 degrees +/- 3.5 degrees) was significantly smaller than that of preoperative one(5.9 degrees +/- 5.1 degrees) in group B (P < 0.05).

The modified open door laminoplasty using anchor method was effective on reducing the occurrence of axial symptoms and loss of cervical curvature and to the benefit of early functional training.