Open-door cervical laminoplasty with preservation of posterior structures

Abstract

Objective To demonstrate that preservation of all posterior structures during open-door laminoplasty (ODL) is associated with a significant preservation of motion. Methods Fifteen patients underwent cervical ODL by one surgeon for treatment of cervical spondylotic myelopathy. An open-door technique was employed, and the laminae on the open side were reconstructed using miniplates with allograft strut bone graft. All spinous processes and interspinous and supraspinous ligaments were preserved within the operative levels and between supra- and subjacent levels in all patients. Postoperative radiographs were obtained 1.5, 3, 6, and 12 months. Computed tomography scans were obtained at 12 months. Results There were no significant intraoperative or perioperative complications. Postoperatively, the neutral angle was 6.8 ± 11.5 degrees (95% confidence interval: 0.5 to 13.1), representing a loss of lordosis of 3 degrees (not significant). The difference between the preoperative and postoperative arc range of motion was 5.96 ± 11.9 degrees (confidence interval: -0.62 to 12.5). The average percent loss of motion was 3.5% ± (0.1 to 6.9%). Four patients had an increased range of motion postoperatively. Conclusion Open-door laminoplasty with preservation of all posterior structures provides greater preservation of motion than has been previously described.

Keywords: alignment; cervical spondylotic myelopathy; laminoplasty; open-door laminoplasty; range of motion.

Figure 1

Anatomic diagram of the posterior ligamentomuscular structures. (A) Posterior exposure of the spine showing the ligamentum nuchae (1) and the burr path on the open side (2). (B) An oblique view of the spine with an idealized exposure of the cord demonstrating the interspinous muscles, which remain intact where possible (3), and the terminal end of the construct with an intact ligamentum nuchae (4).

Figure 2

Posterior tangent method. The posterior tangent method involves the measurement of the angle created by the vertex of two lines shown here in red: the posterior body of C2 and the posterior body of C7.

Figure 3

Case example: Pre- and postoperative range of motion. This 52-year-old man presented with a several-year history of progressive bilateral arm pain and numbness, along with gait and fine motor skills difficulties over the past year. Postoperatively, he had complete resolution of pain, numbness, and motor symptoms. (A–C) Plain films demonstrating preoperative neutral, flexion, and extension views, and (D–F) postoperative comparison films.