Incidence and Risk Factors for Neurological Deterioration in Posterior Corrective Surgeries for Severe Angular Kyphotic Deformities: A 10-Year Institutional Retrospective Study

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: Neurological deficit is one of the dreaded complications of kyphotic deformity correction procedures. There is inconsistency in the reports of neurological outcomes following such procedures and only a few studies have analyzed the risk factors for neurological deficits. We aimed to analyze the factors associated with neurological deterioration in severe kyphotic deformity correction surgeries. METHODS: We performed a retrospective study of 121 consecutive surgically treated severe kyphotic deformity cases (49 males, 56 females) at a single institute (May 1st 2008 to May 31st 2018) and analyzed the risk factors for neurological deterioration. The demographic, surgical and clinical details of the patients were obtained by reviewing the medical records. RESULTS: 105 included patients were divided into 2 groups: Group A (without neurological deficit) with 92 patients (42 males, 50 females) and Group B (with neurological deficit) with 13 patients (7 males, 6 females) (12.4%). Statistically significant difference between the 2 groups was observed in the preoperative sagittal Cobbs angle (p < 0.0001), operative time (p = 0.003) and the presence of myelopathic signs on neurological examination (p = 0.048) and location of the apex of deformity (p = 0.010) but not in other factors. CONCLUSIONS: Preoperative Sagittal Cobbs angle, presence of signs of myelopathy, operative time and location of apex in the distal thoracic region were significantly higher in patients with neurological deterioration as compared to those without neurological deterioration during kyphotic deformity correction surgery. Distal thoracic curve was found to have 4 times more risk of neurological deterioration compared to others.