A Novel Drill Navigation Template Combines Preoperative Simulation in Expansive Open-Door Laminoplasty

To evaluate the effects of preoperative simulation based on patient-specific vertebral models, and computer-assisted designed drill navigation templates in expansive open-door laminoplasty (EOLP).

We retrospectively analyzed 18 consecutive patients who underwent EOLP, 11 patients (45 vertebrae) were treated with traditional EOLP (traditional group) and 7 patients (28 vertebrae) were treated with EOLP aided by the drill navigation template and preoperative simulation (template group). We assessed the operation time, intraoperative blood loss, hospitalization expenses, visual analog scale (VAS), Japanese orthopedic association (JOA), neck disability index (NDI), Pavlov's ratio, laminoplasty opening size (LOS), hinge fracture rate and trough positions.

The operation time of template group (98.6 ± 13.0 minutes) was significantly shorter (P < 0.05) than that of traditional group (125.4 ± 13.2 minutes). Both groups achieved similar hospitalization expenses and significant improvement in VAS, JOA score, NDI, and Pavlov ratio. The postoperative hinge fracture rate of template group (0%; 0/28) was significantly lower (P < 0.05) than that of traditional group (11.1%, 5/45). In template group, all the troughs (56/56 [100%]; 28/28 on the hinge side and 28/28 on the open side), while in traditional group, only 72.2% (65/90; 31/45 on the hinge side and 34/45 on the hinge side) of the troughs were at the proper hinge position.

Drill navigation template and preoperative simulations in EOLP are technically feasible. With the help of templates and preoperative simulation, shorten operation time, accurate trough positioning, decrease incidence of hinge fracture and could be acquired. This technique should be further studied and affirmed in clinical applications.