Long-term Systemic Metal Distribution in Patients With Stainless Steel Spinal Instrumentation. Issue 3 (April 2015)

• Record Type: Journal Article
• Authors: Savarino, Lucia; Greggi, Tiziana; Martikos, Konstantinos; Lolli, Francesco; Greco, Michelina; Baldini, Nicola
• Is Part Of: Journal of spinal disorders & techniques. Volume 28:Issue 3(2015)
• Publication Date: 2015-04
• Subjects: Spinal cord -- Diseases -- Periodicals; Spinal cord -- Surgery -- Periodicals; Spinal Diseases -- therapy -- Periodicals; Cordotomy -- methods -- Periodicals; Spinal Cord Diseases -- therapy -- Periodicals; Spinal Fusion -- methods -- Periodicals; Spine -- surgery -- Periodicals; 616.73
• DOI: 10.1097/BSD.0b013e31826eaa27
• Languages: English
• ISSNs: 1536-0652

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Study Design:</title> <p>Case-control study.</p> </sec> <sec> <title>Objective:</title> <p>To verify whether metal ions in the serum of patients bearing spinal stainless steel instrumentation were elevated over the long-term period after implantation of stainless steel prostheses and to determine whether these levels could predict potential unfavorable outcomes.</p> </sec> <sec> <title>Summary of Background Data:</title> <p>Instrumented spinal arthrodesis, the standard procedure to correct scoliosis, routinely remains in situ for the lifetime of the patient. Elevated metal ion levels have been reported at short-term follow-up, but the long-term status, possibly related to systemic toxic effects, is unknown.</p> </sec> <sec> <title>Methods:</title> <p>Twenty-two patients treated for scoliosis with posterior spinal arthrodesis using stainless steel instrumentation were included. Minimum follow-up was 10 years. Oswestry Disability Index and visual analog scale were recorded. Chromium (Cr) and nickel (Ni) levels were measured (ng/mL) and compared with levels in a control group including 30 healthy subjects. A receiver-operating characteristic curve was calculated on the basis of the clinical assessment (pain and disability) and the x-ray picture; the cutoff values for the parameters were settled, and the ion-testing potential was considered as a surrogate marker for failure.</p> </sec> <sec> <title>Results:</title> <p>The level of Cr was significantly increased in patients, compared with controls (<italic>P</italic>=0.018). A remarkable Cr release without any clinical-radiologic sign was recorded in some female patients. A high specificity (93%), positive likelihood ratio (7.00), and overall accuracy (77%) were calculated for Cr; these indicate a high risk of failure when the levels exceeded the cutoff value, which was 0.6 ng/mL. No significant difference between the groups was found for Ni (<italic>P</italic>=0.7).</p> </sec> <sec> <title>Conclusions:</title> <p>Cr testing is suggested as a reliable marker for the malfunctioning assessment and as a support for standard procedures, especially with doubtful diagnosis. Furthermore, high levels of Cr ions were observed in female patients. This finding deserves attention especially when counseling young fertile women.</p> </sec> </abstract>