Background <p>Anterior cervical discectomy and fusion (ACDF) is a standard treatment for cervical degenerative pathologies. However, complications such as cage subsidence, nonunion, and postoperative kyphotic deformity may occur, leading to persistent pain and neurological symptoms. While anterior revision surgery is the conventional approach, some patients may require additional posterior surgery. Pedicle subtraction osteotomy (PSO) is an established technique for sagittal correction, commonly used in thoracolumbar deformity.</p> Case presentation <p>A 49-year-old male first presented with progressive neck pain and C5 radiculopathy 18 months after ACDF at C4-C6. He had subsequently undergone posterior bilateral C5 foraminotomy at another center, but symptoms persisted. Imaging showed cage subsidence with a focal kyphosis of 18° along with anterior osteophytic bridging and instability. Anterior revision would have required corpectomy and multilevel reconstruction, sacrificing more segments. Additionally, removing anterior osteophytes to achieve proper realignment posed risks to the pharynx and neural structures. Nevertheless, persistent neck pain and instability would have required an additional posterior stabilization. Given the patient’s specific situation, a posterior-only approach with C5 PSO was chosen to achieve correction and fusion with no additional segment sacrifice.</p> Outcome <p>We successfully performed a PSO at C5 to correct focal cervical kyphosis by 30°. The patient demonstrated significant pain relief and resolution of radicular symptoms, and restoration of cervical alignment. The Neck Disability Index improved from 40% to 18%, and he returned to work without daily analgesia. The implants were removed 1 year postoperatively after confirmed solid fusion.</p> Conclusion <p>This is the first reported case of C5 PSO for focal cervical kyphosis following failed ACDF. The procedure provided effective deformity correction.</p>