Aims. We present a case series of five patients who had revision surgery
following magnetic controlled growing rods (MGCR) for early onset
scoliosis. Metallosis was found during revision in four out of five
patients and we postulated a mechanism for rod failure based on
retrieval analysis. Patients and Methods. Retrieval analysis was performed on the seven explanted rods.
The mean duration of MCGR from implantation to revision was 35 months
(17 to 46). The mean age at revision was 12 years (7 to 15; four
boys, one girl). Results. A total of six out of seven rods had tissue metallosis and pseudo-capsule
surrounding the actuator. A total of four out of seven rods were
pistoning. There were two rods which were broken. All rods had abrasive
circumferential markings. A significant amount of metal debris was
found when the actuators were carefully cut open. Analytical electron
microscopy demonstrated metal fragments of predominantly titanium
with a mean
