2021 Volume 12 Issue 10 Pages 1251-1256
Introduction: Surgical treatment for adult spinal deformity (ASD) improves the patient's quality of life; however, ASD surgery is associated with a high complication rate. The most frequent complication of ASD surgery is rod fracture after long-range fixation as an implant-related complication. Rod fracture often occurs due to pseudarthrosis or non-union and is most commonly observed after 5 years of the surgery with a lower incidence of late onset. Here, we report the cases of two patients with late-onset rod fracture who were treated at our hospital. Case 1 was that of a 64-year-old woman with paralytic scoliosis. Thirteen years after her surgery, she had a fracture of the vertebral body and a fracture of the rod at the L2 level, which had achieved bone union within the range of fixation. She had persistent low back pain; therefore, she underwent revision surgery to replace the rod and add an anterior fixation.
Case 2 was that of a 39-year-old man with congenital scoliosis. Six years after his surgery, he had rod fracture at the L3-4 level without interbody fusion. The pain persisted; therefore, he underwent revision surgery to replace the rod and add an anterior fixation.
Conclusions: In both cases, rod fracture occurred after >5 years of the initial surgery. In case 1, the fracture and rod fracture occurred at the same time at the L2 level where the anchor was weak owing to osteoporosis of the long-term fixation vertebral body. In case 2, the rod fracture occurred at the L2 level where interbody fusion was not performed. In cases where mechanically vulnerable areas persist after the surgery, long-term follow-up is necessary owing to the possibility of late-onset rod fracture even after bone union.
