Among the various conditions affecting children's spinal health, congenital odontoid dysplasia stands out due to its insidious onset and potentially life-threatening complications, necessitating heightened awareness among both parents and clinicians. Recently, the Department of Spine Surgery at Children’s Hospital of Fudan University successfully applied cutting-edge technologies to treat a pediatric patient with this rare condition, effectively stabilizing atlantoaxial instability and restoring spinal function.
Nine-year-old Xiaoxuan (pseudonym) had experienced persistent torticollis for nearly one year. Initially attributed to poor posture by his parents, repeated attempts to correct it proved ineffective. Six months prior to presentation, he developed restricted neck mobility following physical activity involving forward rolling. Concerned, his family sought care at the Orthopedic Diagnosis and Treatment Center of Children’s Hospital of Fudan University. Comprehensive evaluation by spine specialists revealed the underlying cause: congenital odontoid dysplasia accompanied by atlantoaxial instability.
The odontoid process is a critical bony projection arising from the axis (second cervical vertebra), forming a pivotal articulation with the anterior arch of the atlas (first cervical vertebra). It serves as the central stabilizer for rotational movement of the head and upper cervical spine. In Xiaoxuan’s case, abnormal embryonic development resulted in failure of fusion between the odontoid and the body of the axis, leaving a free-floating ossicle situated between the atlas and axis. This anomaly compromised the structural integrity of the atlantoaxial joint, leading to pathological instability—clinically manifesting as an unstable, wobbly head position.
Dr. Wang Dahui, Vice President and Chief of Orthopedics at Children’s Hospital of Fudan University, emphasized that while mild cases may present with torticollis, neck pain, and limited motion, severe instances can result in catastrophic consequences. Even minor trauma—such as a fall or sudden deceleration—may trigger acute dislocation, compressing the high cervical spinal cord and potentially causing paralysis, respiratory failure, or cardiac arrest.
Given the anatomical complexity and proximity to vital neural and vascular structures at the craniocervical junction—the so-called “surgical forbidden zone”—conventional surgical approaches carry significant risks and demand exceptional precision. To address this challenge, the spinal surgery team leveraged an advanced digital diagnostic and therapeutic platform to develop a personalized, minimally invasive, navigation-guided intervention strategy focused on accurate fixation and stabilization.
Prior to surgery, meticulous preoperative planning was conducted. Under Dr. Wang Dahui’s leadership, the clinical team imported high-resolution cervical CT data into the hospital’s 3D printing facility to generate a life-sized, anatomically accurate physical model of Xiaoxuan’s atlantoaxial region. This three-dimensional “skeletal sand table” precisely replicated the location, dimensions, and spatial relationships of the free-floating odontoid, adjacent spinal cord, vertebral arteries, and surrounding bony anatomy. The lead surgeon used this model to simulate screw trajectories, optimize implant angles and depths, anticipate procedural challenges, and refine the operative plan. This process not only enhanced surgical preparedness but also enabled the family to visualize the pathology and understand the intricacies of the procedure, thereby reducing anxiety and improving informed consent.
On August 12, during the actual operation, an internationally advanced intraoperative 3D navigation system served as a critical safety tool, functioning akin to real-time “X-ray vision” combined with a “Beidou satellite positioning system.” The system continuously generated high-fidelity 3D images of the surgical field, which were simultaneously displayed on the navigation monitor, enabling dynamic tracking of instrument positions relative to the patient’s anatomy.
Guided by the navigation system, the surgeon operated within a virtual transparent environment, where actual instrument paths aligned seamlessly with pre-planned trajectories. With sub-millimeter precision, fixation screws were safely inserted into narrow, high-risk zones—including the C1 lateral mass and C2 pedicle—immediately adjacent to the vertebral artery and spinal cord. These maneuvers avoided critical neurovascular structures and established a secure foundation for subsequent reduction and internal fixation.
Protected by continuous navigation monitoring, the surgical team successfully reduced the displaced atlantoaxial joint and implanted a customized fixation construct, thereby restoring biomechanical stability to the upper cervical spine. The procedure proceeded smoothly with minimal blood loss and maximal preservation of surrounding neural and vascular tissues.
Postoperatively, Xiaoxuan demonstrated steady recovery. Follow-up imaging confirmed complete anatomical reduction of the atlantoaxial joint and optimal placement of all implants without deviation. Notably, the long-standing torticollis markedly improved, and cervical range of motion progressively returned. Observing their son stand upright and walk confidently, Xiaoxuan’s parents expressed profound relief and gratitude. He was discharged on August 19 following successful rehabilitation.
Dr. Wang Yi, President of Children’s Hospital of Fudan University, highlighted that Xiaoxuan’s case exemplifies the center’s ongoing commitment to technological advancement and patient-centered care. It reflects how interdisciplinary integration—between medicine, engineering, and digital innovation—enables breakthroughs in precise diagnosis and individualized treatment planning. This achievement underscores Fudan Children’s Hospital’s leadership in advancing precision medicine through medical-engineering collaboration.