New precise lamina slotting technique for cervical laminoplasty: the sliding positioning method using bone rongeur

To investigate the clinical utility and performance in radiological assessment of the sliding positioning method with bone rongeur in precise lamina slot formation during cervical laminoplasty (CLP).

Data of 153 patients who underwent CLP were enrolled in this study, of which 79 patients underwent surgery using sliding positioning method (sliding positioning group) and 74 patients using traditional slotting method (traditional group). Radiological parameters including bilateral uncinate process vertex width (A1A2), bilateral slotted lamina width (B1B2), laminar decompression margin (B1C1 and B2C2), spinal cord transverse diameter (D1D2), and bilateral slotted lamina diameter (E1E2) were measured. The surgical time, blood loss, modified Japanese Orthopaedic Association (mJOA), visual analog scale (VAS), and Neck Disability Index (NDI) scores were assessed between two groups.

The A1A2 measured by CT exhibited an increasing trend from C3 to C7 segments in both groups (P < 0.001). The B1B2 in C3-C5 segments exceeded that of A1A2 (P < 0.001), while the B1B2 in C6-C7 segments was smaller compared with that of A1A2 (P < 0.05) in both groups. The B2C2 in C3-C5 segments exceeded that in B1C1 (P < 0.05), and B1C1 and B2C2 in C6-C7 segments exceeded that in adjacent segments in the traditional group (P < 0.05). The B1C1 and B2C2 were relatively constant in the sliding positioning group (P >0.05). The MRI measurements indicated that the D1D2 was relatively constant within the C3 to C5 segments, whereas it showed a gradual decline in C6-C7 segments. The E1E2 in C3-C7 segments exceeded that in D1D2 in two groups (P < 0.001). In the sliding positioning group, the intraoperative bleeding volume and surgical time were lower (P < 0.01), and the postoperative mJOA score was higher than those in the traditional group (P < 0.05). In both groups, there was no significant difference in VAS and NDI scores (P > 0.05).

Compared with traditional slotting technique, the sliding positioning technique based on bone rongeur is more precise in lamina slotting, with shorter surgical time, less bleeding, and can achieve better clinical outcome in CLP.