Use of permanently placed metal expandable cages for vertebral body reconstruction in the surgical treatment of spondylodiscitis.

This is a retrospective study of 15 patients treated for spondylodiscitis with implanted metal cages. The purpose of this study is to investigate the outcomes of patients treated with permanently placed metal hardware in vertebral body reconstruction for spondylodiscitis. The use of metal implants in the face of infection has classically been discouraged in orthopedic literature because of the ability of bacteria to form biofilms on metal surfaces. Traditional treatment of spondylodiscitis has been aggressive debridement followed by reconstruction with bone grafts. Expandable metallic cages made reconstruction of these defects significantly easier. However, concern exists that metallic implants affect the resolution of infection. A search of the authors' patient database from 2005 to 2009 revealed 21 patients with spondylodiscitis treated with anterior debridement and reconstruction with an expandable metallic cage. Fourteen patients (15 cases) had sufficient documented clinical follow-up and were available for review. Resolution of infection was determined by evaluating symptoms, laboratory data, and final radiographic result. Of the 15 cases, all had clinical resolution of infection with an average follow-up time of 25 months. An average loss of 1.9° of correction was observed when comparing final follow-up radiographs with initial postoperative radiographs. Radiograph review revealed no extensive osteolysis around the hardware or progressive collapse. These results suggest that the use of expandable metal cages maintains alignment while not perpetuating infection. The spine appears to provide a unique environment that permits the use of metal implants in the setting of infection.