Correction Hinge in the Compromised Cord for Severe and Rigid Angular Kyphosis with Neurologic Deficits

Study Design: Retrospective study.

Objective: To report the use of a reliable and safe technique for the surgical management of severe and rigid angular kyphotic deformities with neurologic deficits.

Summary Of Background Data: Severe and rigid angular kyphotic deformity can result in difficult to treat neurologic deficits. Previously described techniques are an ordeal for both the patient and the surgeon and run the risk of damaging the compromised spinal cord because of stretch, compression, deformation, and direct intraoperative cord manipulation during the procedure.

Methods: Seventeen consecutive patients with neurologic deficits due to severe and rigid angular kyphotic deformity were treated with circumferential neurologic decompression and correction by one-shot in situ cantilever bending at the apex of the deformity with a fixed hinge in the compromised spinal cord. The procedure involved minimal manipulation, stretching, compression, and deformation of the vulnerable cord. Minimum follow-up after surgery was 2 years (range: 2.5-6.4 years). Mean Cobb angle of kyphotic deformity was 105.3 degrees (range: 85 degrees -121 degrees ). All patients exhibited neurologic deficits. There were 6, 7, and 4 patients classified as Frankel B, C, and D, respectively. Etiologic diagnoses were congenital kyphosis in 6 and postinfectious kyphosis in 11 patients.

Results: Mean operation time was 194 minutes and average blood loss was 1621 mL. All patients showed neurologic improvement. Two of the Frankel B patients improved to Frankel E and 2 each to Frankel D and C. Two of the Frankel C patients improved to Frankel D, whereas 5 improved to Frankel E. All Frankel D patients improved to Frankel E. Kyphotic deformity correction was 30% in the sagittal plane. Complications were minor.

Conclusion: Circumferential neurologic decompression and one-shot cantilever bending correction with a fixed hinge in the compromised cord is a safe and effective alternative for surgical treatment of severe and rigid angular kyphotic deformities with neurologic deficits.