Precision restoration of complex cervical instability and decompression for neurofibromatosis type I: a case report using patient-specific 3D-printed templates.

Severe cervical kyphosis concurrent with neurofibromatosis type 1 (NF-1) and large intraspinal tumors presents a dual challenge of oncological control and biomechanical reconstruction. We report a rare case of a 14-year-old male with NF-1 secondary to C1-C6 cervical spondylolisthesis, cervical retroversion, retrolisthesis of the C3 vertebral body (less than 1/2 of the vertebral diameter), C2 dislocation, atlantoaxial rotational dislocation, and a large intradural tumor, which caused acute spinal cord compression and neurofunctional deficits. An integrated surgical strategy combining microsurgical tumor resection with 3D-printed corrective fusion was implemented. Intraoperatively, gross total resection (GTR) of the tumor was achieved, followed by precise pedicle screw fixation assisted by patient-specific 3D-printed guides. This comprehensive approach prevented further neurological damage, and the patient achieved satisfactory clinical outcomes postoperatively. NF-1 is an autosomal dominant genetic disorder with an incidence of 1/3,000-1/4,000, characterized by diverse manifestations including skin abnormalities, neurological tumors, and musculoskeletal abnormalities. Approximately 50% of cases arise from Case description: A 14-year-old Han male student with no prior medical history was admitted for a 1-year history of a large right neck mass (15 × 9 cm) and 2 months of progressive generalized weakness. Physical examination revealed multiple café-au-lait macules (>30 mm) and a large cervical mass, consistent with NF-1. Neurological assessment showed decreased muscle strength in all limbs (grade 3), indicating incomplete spinal cord injury. Imaging (MRI/CT) demonstrated an intradural-intramedullary tumor extending through the intervertebral foramen, causing severe spinal cord compression and multiplanar instability (C1-C6).The patient was diagnosed with NF-1, severe cervical kyphosis, and an intraspinal tumor. He underwent posterior decompression, microsurgical GTR of the tumor (confirmed as neurofibroma via intraoperative frozen section), and occipitocervicothoracic fusion assisted by 3D-printed guides. The integrated surgery successfully restored spinal stability and decompressed the spinal cord. Conclusion: Severe cervical retroversion combined with large NF-1 tumors is rare and technically demanding. A precision-medicine-based model integrating tumor management and digital orthopedic technology is essential for such high-risk cases. Preoperative planning using 3D digital technology enabled precise screw placement, while microsurgical techniques ensured safe and complete tumor resection. This integrated strategy effectively prevented permanent neurological deficits and resulted in satisfactory postoperative outcomes.