Objective: To determine the efficacy of open-door laminoplasty using stand-alone type autologous bone spacers for preserving enlarged laminae in patients with cervical myelopathy.

Methods: Patients who underwent open-door laminoplasty for cervical myelopathy using stand-alone type autologous bone spacers and had computed tomography (CT) 1 week and 1 year after surgery were included in this study. There were 20 men and 13 women, with an average age of 65.0 (range 37–86) years. Autogenous bone spacers made from spinous processes were used in all cases. Slits were made on both sides of the spacers. The lamina was raised with a curette, and a spacer was inserted without any sutures. Before surgery and at 1 week and 1 year after surgery, the anteroposterior diameter (APD) of the spinal canal was measured using the CT-multiplanar reconstruction (MPR) midsagittal plane. The bone union rate of the hinge side of each lamina and autogenous bone spacer was determined using CT images taken 1 year after surgery.

Results 1 year after surgery were evaluated using the Japanese Orthopaedic Association (JOA) score. Results: The APD increase rate was 56.3 ± 21.3% 1 week after surgery and 51.7 ± 20.6% 1 year later. The average APD decrease rate was 2.9 ± 3.8%. The bone union rate on the hinge side was 100%, and of the autologous bone spacer was 93.8% 1 year after the surgery. The JOA score averaged 10.1 before surgery and 13.3 1 year after surgery (out of a total score of 17). The average improvement rate was 46.3 ± 26.4%.

Conclusions: We devised and implemented a technique of inserting autologous bone spacers between the opened lamina and the lateral mass without sutures. The enlarged spinal canal was maintained 1 year after surgery. This simple method does not require any instrumentation or additional cost to stabilize the opened lamina.