A case report and reconsideration of pathogenesis: C5 palsy after corrective surgery for severe congenital cervicothoracic scoliosis.

OBJECTIVE

This case report presents a rare case of C5 nerve root palsy following corrective surgery for severe congenital cervicothoracic scoliosis in a child, and explores its distinctive pathogenesis and treatment strategy.

METHODS

This study was approved by the Medical Ethics Committee of the Second Affiliated Hospital of Kunming Medical University (PJ-2021-100), and informed consent was obtained from the patient's guardian. The clinical data of a 9-year-old boy with congenital cervicothoracic scoliosis (Cobb angle of 99°) who underwent posterior corrective instrumentation and fusion were retrospectively analyzed. Typical C5 palsy developed on postoperative day 7. Imaging studies and the clinical course were used to identify the responsible mechanism.

RESULTS

Postoperatively, left deltoid strength decreased to grade II/III. CT excluded direct implant impingement, and no laminectomy had been performed, thus excluding the classic "posterior cord drift" hypothesis. Comparative imaging revealed a significant reduction in the vertical diameter of the C4-C5 foramen. We concluded that reduction maneuvers had transmitted excessive traction through the C5 pedicle screw, producing dynamic foraminal stenosis and nerve root stretching. Conservative management (with cervical traction and hyperbaric oxygen) was instituted, and complete neurological recovery was documented at 3 months.

CONCLUSION

In cervical deformity surgeries performed without decompression, iatrogenic alteration of the foramina's geometry, produced by corrective forces, is an important and frequently overlooked mechanism of postoperative C5 palsy. Surgeons should avoid overtightening a single screw during rod reduction; once the complication occurs, systematic conservative treatment usually yields a favorable outcome.