Abstract
INTRODUCTION: The occurrence of metallosis after spine surgery is a rare phenomenon. The accumulation and deposition of metallic nanoparticles, especially cobalt and chromium, elicit a local inflammatory response by modulating the expression of cytokines, ultimately manifesting as a pseudotumor. This process is considered an aseptic lymphocyte-dominated vasculitis-associated lesion or adverse local tissue reaction (ALTR). METHODS: We present a case of metalloma that developed 12 years after surgery for adolescent idiopathic scoliosis (AIS). RESULTS: After a piecemeal decompression of the pseudocyst, additional internal fixation instrumentation, and a pseudarthrosis revision with bone transplantation, the patient regained all prior flexibility and remained pain free. CONCLUSION: We speculate that the proposed mechanism of instrumentation failure in our patient was over-aggressive postoperative exercise with pseudoarthrosis and metal-on-metal corrosion, leading to ALTR in the spinal canal.