Reinstrumentation for rapid curve progression after implant removal following posterior instrumented fusion in adolescent idiopathic scoliosis: a case report

BACKGROUND CONTEXT: Spinal implants are occasionally removed due to infection or soft tissue irritation secondary to prominence. Several studies have reported loss of scoliotic curve correction after implant removal. However, further review of the literature reveals no similar cases of rapid curve progression following implant removal in patients with adolescent idiopathic scoliosis (AIS) necessitating repeat posterior instrumented fusion. PURPOSE: To describe a 15-year-old female AIS patient treated by posterior instrumented fusion, who developed unusual rapid coronal and sagittal curve progression after implant removal. STUDY DESIGN: Case report. METHODS: Retrospective case report. RESULTS: A 15-year-old female with Lenke type 1A AIS underwent a successful posterior spinal fusion with instrumentation. She initially had no complications after surgery, but three years after instrumentation, her implants were removed due to pain secondary to implant prominence. Fifteen months after removal, the main thoracic curve increased, compared with radiographs taken before removal, from 29° to 57°. This development required the patient to undergo additional surgery, which involved multiple osteotomies and posterior reinstrumentation. CONCLUSIONS: We must acknowledge that a remarkable amount of progression can occur rapidly following implant removal in scoliotic patients. Taking this into consideration,we need to carefully explain to patients that removal of their implants entails a risk of progressive deformity and that they need to follow-up with their physician after implant removal.