Complete bone fusion in failed back surgery syndrome using teriparatide in neurosyphilis: A case report

INTRODUCTION AND IMPORTANCE: Syphilis is a sexually transmitted disease that appears in various organs. Neurosyphilis in the spine is infrequent, and report of failed spinal arthrodesis surgery is rare. We report the first presentation of complete bone fusion in failed back surgery syndrome with teriparatide. CASE PRESENTATION: A 65-year-old man presented to the outpatient clinic after being admitted to the spine department. The patient visited the neurology department 30 years prior for syphilitic myelitis and had been walking with a cane. He underwent an L5–S1 stenosis operation earlier. Severe proximal adjacent L4–L5 level stenosis was observed due to syphilitic gumma with cauda equina syndrome. A posterior decompression and posterolateral fusion to S1 were performed. Four weeks post-surgery, bilateral lower extremity muscle weakness recurred, and a radiographic examination revealed bilateral posterior screw loosening and fracture of the fourth lumbar vertebrae body. After the stagnant fluid and metal removal, for the augmentation of bone union, teriparatide was used for six months, and a complete bone union was confirmed by radiography without pain. CLINICAL DISCUSSION: Spinal syphilitic gumma has been rarely reported, most of which undergo surgical treatment. Surgical decompression and fixation with a pedicle screw are usually needed. There are complications after spinal surgery using a pedicle screw fixation, and parathyroid hormone (PTH) might be suitable for application in the prevention of nonunions or to augment bone fusion. CONCLUSION: This case report is the first description of complete spinal bone fusion in failed back surgery syndrome using teriparatide in tertiary syphilis.