Congenital cervical spondylolytic spondylolisthesis is a rare and complex disorder of the cervical spine. Surgical treatment is reserved for those symptomatic patients who do not improve with conservative management. A 34-year-old man presented with bilateral C7 radiculopathy for the past 6 months. Magnetic resonance imaging of the cervical spine revealed grade II C6-7 spondylolisthesis. Computed tomography showed the presence of spondyloarthritis, bilateral pedicle dysplasia, bilateral isthmic defect, and spinous process schisis. Dynamic radiographs showed no signs of vertebral instability. Dynamic magnetic resonance imaging showed kinking of the spinal cord over the fulcrum of C6-7 kyphosis during flexion, with no signs of myelopathy. The patient underwent C6-7 anterior fusion surgery. His symptoms improved postoperatively, with a 2-month computed tomography scan showing initial bony bridging. The absence of evident instability on radiography does not always correspond to the absence of actual functional compression of neurological structures. Spinal misalignment, muscle dysfunction, and kyphotic deformity with kinking of the spinal cord and stretching of the nerve roots may also contribute to the development of symptoms. In this setting, dynamic magnetic resonance imaging can be extremely useful. Single-level anterior fusion surgery without posterior fixation can achieve solid fusion and improve the clinical conditions of patients. https://thejns.org/doi/10.3171/CASE24174.