Comparison of Early Surgical Outcome between Unilateral Open-Door Laminoplasty and Midline Splitting Laminoplasty

Objective : Various techniques of cervical laminoplasty have been developed to decompress the spinal canal in patients with multilevel cervical spondylotic myelopathy. This study compared the early surgical outcomes between unilateral open-door laminoplasty and midline splitting cervical laminoplasty. Materials and Methods : From March 2004 to August 2005, we performed cervical laminoplasty in 34 patients with cervical myelopathy. Of these patients, 24 were treated by unilateral open-door laminoplasty [open-door group] and 10 by midline splitting cervical laminoplasty [splitting group]. The mean duration of follow up was 9.2 months in the open-door group and 15.8 months in the splitting group. We retrospectively analyzed neurological outcomes using the Japanese Orthopedic Association [JOA] score, and compared the radiological changes between the two groups. Results : Postoperative JOA score and recovery rate were $13.29{\pm}4.01$ and $56.28{\pm}44.91%$ in the open-door group and $15.75{\pm}0.88$ and $72.69{\pm}19.99%$ in the splitting group. There was no statistical difference between the two groups [p>0.05]. Regarding the radiological assessment, the increase of postoperative axial canal area was $63.23{\pm}23.24%$ in the open-door group and $42.30{\pm}14.96%$ in the splitting group [p<0,05]. Conclusion : There was no statistical difference in the neurological outcome when the early surgical outcomes of the open-door group and the splitting group were compared. However, the open-door group showed wider cervical spinal canal areas than the splitting group.