Bilateral Spondylolysis of Lumbar Vertebra Secondary to Long Spinal Fusion for Idiopathic Scoliosis: A Case Report and Review of Literature

Abstract

Background: Lumbar spondylolysis is a common cause of low back pain in adolescents. A lot of adolescent idiopathic scoliosis with concomitant spondylolysis has been reported before, but only two cases with acquired spondylolysis following long fusion for scoliosis were reported. We described another similar rare case and discussed its causes and treatment options in this paper.

Case presentation: A 17-year-old female underwent growing rod implantation, growing rod extension, and final long spinal fusion for idiopathic scoliosis. Then, she suffered from low back pain with a VAS of 1-2 points and gradually aggravated to a VAS of 7-8 points at 3.5 years after the final fusion. The X-ray images showed that there was L4-S1 instability. And the CT scan images showed new bilateral spondylolysis of L5.

Conclusions: These findings suggested that distal mechanical stress might cause spondylolysis of the distal vertebra following long fusion for scoliosis. Surgeons should keep instrumentation as short as possible and avoid choosing a low lumbar as LIV when they decide on the fusion levels.

Keywords: Case Report; Idiopathic Scoliosis; Long Fusion; Spondylolysis.

FIGURE 1

(A) A 10‐year‐old female patient with idiopathic scoliosis underwent the growing rod implantation (T4‐L3). (A and B) Whole spine erect AP and lateral position X‐ray before initial operation; (C and D) whole spine erect AP and lateral position X‐ray after the growing rod implantation.

FIGURE 2

(A and B) The patient underwent the final fusion (T3‐L4) after two growing rod extensions. The X‐ray shows the loosening of two proximal pedicle screws and the distal “adding‐on” phenomenon; (C and D) the patient was performed the final spinal fusion from T3 to L4.

Figure 3

X‐ray at 3.5 years after the final fusion. (A and B) The orthopaedic effect and implant location are satisfactory, new spondylolysis of L5 was found; (C and D) lumbar spine forward flexion and backward extension X‐ray show L4‐S1 instability and spondylolysis of L5.

Figure 4

The sagittal and axial images of CT scans or MRI for the pars interarticularis of L5. (A and B, J and K) No isthmic abnormality at L5 before the surgery (2017); (C and D, L and M) no isthmic abnormality at L5 before the final fusion surgery (2020); (E and F, N) first discovery of spondylolysis at L5 (2023); (G and H, I) MRI shows L5 spondylolysis and lumbar disc degeneration (L5/S1) at the last follow‐up at 2024.