The 12th rib syndrome is a disease that causes pain between the upper abdomen and the lower chest. It is assumed that the impinging on the nerves between the ribs causes pain in the lower chest, upper abdomen, and flank. A 74-year-old female patient visited a pain clinic complaining of pain in her back, and left chest wall at a 7 on the 0-10 Numeric Rating scale (NRS). She had a lateral fixation at T12-L2, 6 years earlier. After the operation, she had multiple osteoporotic compression fractures. When the spine was bent, the patient complained about a sharp pain in the left mid-axillary line and radiating pain toward the abdomen. On physical examination, the 10th rib was not felt, and an image of the rib-cage confirmed that the left 10th rib was severed. When applying pressure from the legs to the 9th rib of the patient, pain was reproduced. Therefore, the patient was diagnosed with 9th rib syndrome, and ultrasound-guided 9th and 10th intercostal nerve blocks were performed around the tips of the severed 10th rib. In addition, local anesthetics with triamcinolone were administered into the muscles beneath the 9th rib at the point of the greatest tenderness. The patient's pain was reduced to NRS 2 point. In this case, it is suspected that the patient had a partial resection of the left 10th rib in the past, and subsequent compression fractures at T8 and T9 led to the deformation of the rib cage, causing the tip of the remaining 10th rib to impinge on the 9th intercostal nerves, causing pain.