Expert’s comment concerning Grand Rounds case entitled “Intraspinal canal rod migration causing late-onset paraparesis 8 years after scoliosis surgery” (I. Obeid et al. Eur Spine J; 2014, DOI 10.1007/s00586-014-3367-y)

The complication rate in adolescent idiopathic scoliosis (AIS) surgery is very low where, neurologic deficit occurs in less than 1 % and the infection rate is less than 3 % [1]. Moreover, AIS patient reported outcomes are not different, between patients who had infection or not [1]. This case report is very interesting, describing an uncommon postoperative complication of adolescent idiopathic scoliosis surgery [2]. This paper reports progressive paraparesis due to intraspinal rod migration after ASD surgery with Propionibacterium acnes (P. acnes) infection and highlights the lack of knowledge on the consequences of these late-presenting infections. Indeed, intraperitoneal or intramediastinal rod migration after spinal surgery has been previously described; however, intraspinal rod migration with late-onset paraparesis has never been reported after such a surgery [3, 4]. Only few papers described the late consequences of P. acnes infection, and others described neurologic complications due to intraspinal metallosis [1, 5–12].