A long-term follow-up study on spinal deformity and instability following laminectomy for spinal cord tumor was conducted. Twenty-nine patients, aged 10 to 76 years, were followed up for 7 to 36 years after laminectomy. Post-laminectomy kyphosis occurred in 8 patients (27.6%) and instability in 7 patients (24.1%). Facet joints were found to be the most important in the development of kyphosis and instability. The study included 29 patients who underwent laminectomy for spinal cord tumors. The average age at surgery was 35.8 years, and the average age at follow-up was 54.0 years. The most common tumor was neurinoma, accounting for 18 cases. Kyphosis was observed in 8 cases (27.6%), and scoliosis in 6 cases (20.7%). Instability was found in 7 cases (24.1%). Other findings included bone formation at the laminectomy site in 3 cases, and the occurrence of OPLL and OYL increase in 1 case each. Kyphosis and instability were not significantly related to the age at surgery or the duration of follow-up. The cervical region showed instability in all 4 cases, while kyphosis was observed in 4 out of 13 cases in the thoracolumbar region. Facet joint destruction was found to be a major cause of kyphosis, with 67% of facet joint destruction cases showing kyphosis and 75% of kyphosis cases showing facet joint destruction. The study highlights the importance of preserving facet joints to prevent post-laminectomy kyphosis. Long-term follow-up is necessary to monitor spinal deformity and instability, especially in children who may develop severe deformities and instability. The study also emphasizes the need for careful surgical planning, particularly in young patients, to minimize the risk of postoperative spinal deformity and instability.A long-term follow-up study on spinal deformity and instability following laminectomy for spinal cord tumor was conducted. Twenty-nine patients, aged 10 to 76 years, were followed up for 7 to 36 years after laminectomy. Post-laminectomy kyphosis occurred in 8 patients (27.6%) and instability in 7 patients (24.1%). Facet joints were found to be the most important in the development of kyphosis and instability. The study included 29 patients who underwent laminectomy for spinal cord tumors. The average age at surgery was 35.8 years, and the average age at follow-up was 54.0 years. The most common tumor was neurinoma, accounting for 18 cases. Kyphosis was observed in 8 cases (27.6%), and scoliosis in 6 cases (20.7%). Instability was found in 7 cases (24.1%). Other findings included bone formation at the laminectomy site in 3 cases, and the occurrence of OPLL and OYL increase in 1 case each. Kyphosis and instability were not significantly related to the age at surgery or the duration of follow-up. The cervical region showed instability in all 4 cases, while kyphosis was observed in 4 out of 13 cases in the thoracolumbar region. Facet joint destruction was found to be a major cause of kyphosis, with 67% of facet joint destruction cases showing kyphosis and 75% of kyphosis cases showing facet joint destruction. The study highlights the importance of preserving facet joints to prevent post-laminectomy kyphosis. Long-term follow-up is necessary to monitor spinal deformity and instability, especially in children who may develop severe deformities and instability. The study also emphasizes the need for careful surgical planning, particularly in young patients, to minimize the risk of postoperative spinal deformity and instability.