Delayed neurological deficit due to a medially misplaced thoracic pedicle screw during adolescent idiopathic scoliosis correction: a complication 6 years in the making.

Purpose: Neurological deficits developing years after pedicle screw misplacement is a rare phenomenon. Here, we report level IV evidence of a previously asymptomatic medial thoracic pedicle screw resulting in paraparesis after a motor vehicle accident.

Methods: A 21-year-old male presented with acute onset of paraparesis following a motor vehicle collision. Six years prior this incident, the patient underwent a thoracolumbar fusion T4-L4 for AIS performed by an outside orthopedic surgeon. CT scan and CT myelogram illustrated decreased spinal canal diameter and cord compression from a medial T8 pedicle screw.

Results: Surgical removal of the misplaced pedicle screw resulted in a gradual complete recovery sustained over a period of 2 years. This case is compared to those reported in the literature review between 1981 and 2019 concerning delayed neurological deterioration related to misplaced pedicle screw.

Conclusion: This case reports a delayed neurological deficit implicating a misplaced pedicle screw. This phenomenon remains rare since 5 cases were reported in the literature over the last 4 decades. It calls into focus the need for confirmation of safe instrumentation during the intraoperative period. It also illustrates the potential difficult decision-making in regard to asymptomatic misplaced instrumentation.

Level of evidence: IV.