Prevalence of metal hypersensitivity in pediatric spine surgery

Purpose: Delayed metal hypersensitivity reactions can cause complications in spine surgery. Currently, there is no information on the prevalence of metal hypersensitivity in pediatric patients undergoing spine surgery. The objective of this study is to determine the prevalence of metal hypersensitivity in pediatric patients undergoing spinal instrumentation.

Methods: Retrospective chart review of patients who underwent spinal instrumentation with or without fusion at a single institution, from January 1, 2014, to December 31, 2020, was performed. Patients were pre-screened for history of allergic diseases, including previous reaction to metals, prior to surgery. Patch metal allergy testing (PMAT) for metal hypersensitivity was also performed.

Results: Of the 796 pediatric patients who underwent spinal instrumentation procedures from 2014 to 2020, 118 (15%) screened positive for metal hypersensitivity. However, the number of patients with documented evidence of metal hypersensitivity diminished to 26 (3%) after PMAT verification. Nickel hypersensitivity was most prevalent, with 20 patients (16.9% of positive screening; 2.5% of all instrumented patients) demonstrating positive skin patch tests. The other most prevalent metal hypersensitivities included cobalt in 9 patients (7.6%; 1.1%), manganese in 3 patients (2.5%; 0.4%), and copper in 1 patient (0.8%; 0.1%). with a number needed to treat (NNT) of 5.

Conclusions: This study suggests that routine pre-operative PMAT is not necessary in all pediatric spine patients yet should be considered if patients report a history of prior metal hypersensitivity reactions.