500 Section - Late intraspinal canal displacement of cervicothoracic fusion hardware causing high cervical incomplete tetraplegia: functional recovery after intensive rehabilitation and Lokomat-based robotic gait training

Late cranial migration of cervicothoracic hardware caused high cervical incomplete tetraplegia (AIS B, C1), improved after Intensive rehabilitation with Lokomat training (AIS D).

Case Description: A previously healthy adult with a history of C5–T2 posterior stabilization in 2008 and full recovery (AIS E) presented in 2024 with sudden cervical pain, rapidly ascending paresthesia, and quadriplegia. Imaging revealed cranial dislocation of the right fixation rod, penetrating the C3–C4 canal toward C1. Urgent removal was performed, and postoperative assessment showed high cervical incomplete tetraplegia (AIS B, C1). On rehabilitation admission, Barthel 5, SCIM 17, and WISCI II 1 indicated severe disability. A multidisciplinary program, including intensive Lokomat-based gait training, produced marked gains: hip flexion 20→70, hip ROM 45°, and knee ROM 85°. After ten months, Barthel rose to 80, SCIM to 89, and WISCI II to 19, enabling near-independent ambulation.

Discussions: Late intraspinal migration of posterior spinal instrumentation is rare and severe. Unlike prior thoracic cases, this patient developed acute high cervical incomplete tetraplegia from cranial rod migration, not previously reported. Despite the typically poor prognosis of high cervical AIS B injuries, the patient achieved notable neurological and functional recovery. Robotic gait training supported meaningful gains in strength and joint mobility, with progressive improvements leading to near-independent ambulation. This case suggests that intensive, technology-enhanced rehabilitation can promote substantial recovery even after rare, high-severity spinal complications.

Conclusions: To our knowledge, this is the first reported case of this rare cervicothoracic hardware complication. Despite severe onset, the patient achieved substantial neurological and functional recovery over 10 months. Gains in strength, mobility, and gait reflect the efficacy of intensive rehabilitation with robotic gait training, that provided high-repetition, guided locomotor practice supporting motor relearning. The case highlights the need for long-term surveillance after spinal fusion and shows that even severe late complications can allow meaningful recovery with technology-enhanced neurorehabilitation.