Answer to the Letter to the Editor of Yi Shen et al. concerning "Risk factors for adjacent segment pathology requiring additional surgery after single-level spinal fusion: impact of pre-existing spinal stenosis demonstrated by preoperative myelograp

Answer to the Letter to the Editor of Yi Shen et al. concerning "Risk factors for adjacent segment pathology requiring additional surgery after single-level spinal fusion: impact of pre-existing spinal stenosis demonstrated by preoperative myelograp