A Tentative Modeling Study of the Effect of Wall Reactions on Oxidation Phenomena

This paper gives details of a tentative modeling study that investigates the inhibiting effect of internal reactor walls treated with acid..

PEEK interbody devices for multilevel anterior cervical discectomy and fusion: association with more than 6-fold higher rates of pseudarthrosis compared to structural allograft

OBJECTIVECommon interbody graft options for anterior cervical discectomy and fusion (ACDF) include allograft and polyetheretherketone (PEEK). PEEK has gained popularity due to its radiolucent properties and a modulus of elasticity similar to that of bone. PEEK devices also result in higher billing costs than allograft, which may drive selection. A previous study found a 5-fold higher rate of pseudarthrosis with the use of PEEK devices compared with structural allograft in single-level ACDF. Here the authors report on the occurrence of pseudarthrosis with PEEK devices versus structural allograft in patients who underwent multilevel ACDF.METHODSThe authors retrospectively reviewed 81 consecutive patients who underwent a multilevel ACDF and had radiographic follow-up for at least 1 year. Data were collected on age, sex, BMI, tobacco use, pseudarthrosis, and rate of reoperation for pseudarthrosis. Logistic regression was used for data analysis.RESULTSOf 81 patients, 35 had PEEK implants and 46 had structural allograft. There were no significant differences between age, sex, smoking status, or BMI in the 2 groups. There were 26/35 (74%) patients with PEEK implants who demonstrated radiographic evidence of pseudarthrosis, compared with 5/46 (11%) patients with structural allograft (p &lt; 0.001, OR 22.2). Five patients (14%) with PEEK implants required reoperation for pseudarthrosis, compared with 0 patients with allograft (p = 0.013).CONCLUSIONSThis study reinforces previous findings on 1-level ACDF outcomes and suggests that the use of PEEK in multilevel ACDF results in statistically significantly higher rates of radiographic pseudarthrosis and need for revision surgery than allograft. Surgeons should consider these findings when determining graft options, and reimbursement policies should reflect these discrepancies.</jats:sec