In Situ Decompression to Spinal Cord During Anterior Controllable Antedisplacement Fusion Treating Degenerative Kyphosis with Stenosis: Surgical Outcomes and Analysis of C5 Nerve Palsy Based on 49 Patients.

OBJECTIVE: To observe outcomes of anterior controllable antedisplacement fusion (ACAF) in treatment of degenerative kyphosis with stenosis (DKS) and analyze probability of C5 nerve palsy.

METHODS: From 2016 to 2017, a consecutive cohort of adults with DKS underwent ACAF. All patients underwent cervical radiography, computed tomography, and magnetic resonance imaging. Operative duration, blood loss, and hospital stay were estimated. Radiologic assessment included kyphotic correction, decompression width, and spinal canal area. Postoperative curvature of spinal cord was observed on sagittal magnetic resonance imaging. Japanese Orthopaedic Association score was used to evaluate neurologic status. C5 nerve palsy and other complications were recorded.

RESULTS: The study included 49 patients. There was significant kyphosis correction postoperatively (-19.4° vs. 3.5°, P < 0.01). On cross-sectional computed tomography, mean decompression width was 19.0 mm, and spinal canal area was 218.5 mm2 . On sagittal magnetic resonance imaging, spinal cord curvature was classified into 5 types: type I, lordosis; type II, straight with no shifting; type III, straight with shifting; type IV, sigmoid; and type V, kyphosis. After ACAF, the spinal cord was maintained in good curvature with no shifting in all patients. No patient presented with C5 nerve palsy. Mean postoperative Japanese Orthopaedic Association score was significantly better than preoperatively (14.9 points vs. 9.0 points, P < 0.01), with mean improvement rate of 79.8%.

CONCLUSIONS: ACAF provides in situ decompression and good curvature to the spinal cord. Good neurologic recovery is obtained with lower incidence of C5 nerve palsy when ACAF is used to treat DKS.