Levels of systemic metal ions in patients with intramedullary nails

Abstract

Background It is being increasingly recognized that orthopedic implants are associated with adverse tissue responses, mediated by degradation products. Recent interest has been focused on the production of metal ions from hip arthroplasty. Few studies have reviewed fracture fixation devices and their metal ion production

Methods 61 subjects were enlisted into the study, with 3 subgroups. 21 subjects had Russell-Taylor intramedullary tibial nails in situ for 26 (21–32) months (316LVm stainless steel), 20 subjects had TriGen intramedullary tibial nails in situ for 43 (35–51) months (Ti-6Al-4V titanium alloy), and the remaining 20 subjects did not have any implant in situ and served as controls. Blood samples were taken and serum chromium, molybdenum, titanium, aluminium, and vanadium concentrations were measured using inductively coupled plasma (ICP) techniques.

Results The 3 groups were matched for age, sex, and BMI. The subjects with Russell-Taylor nails had elevated levels of chromium (0.10 µg/L) with median concentrations 2.5 times higher than those of the control group. The subjects with TriGen nails had less significantly elevated levels of titanium (6.5 µg/L).

Interpretation Stainless steel implants show significant differences from titanium implants in the dissemination of metal ions. Although the levels of chromium were elevated, the overall levels were modest when compared to published data regarding metal ion release and hip arthroplasty. Intramedullary nails are, however, often used in younger patients. If not removed, they may result in prolonged exposure to metal ions.

MSP and GPA: design of study, collection of specimens, and writing of the manuscript. TDBL: serum analysis performed blind.