Occipitocervical reconstruction with the Ohio Medical Instruments Loop: results of a multicenter evaluation in 30 cases

Abstract

Object. Stabilization of the craniocervical junction (CCJ) remains a significant challenge. In this multicenter study, the authors present the results of an evaluation of a precontoured titanium implant, the Ohio Medical Instruments (OMI) Loop, for craniocervical fixation. Methods. In this multicenter retrospective study the authors evaluated 30 patients (16 female, 14 male; mean age 53.8 years) with rheumatoid arthritis (15 cases), traumatic occipitoatlantoaxial instability (six cases), congenital vertebral anomalies (two cases), instability due to basilar invagination in the setting of Chiari malformation (two cases), or Down syndrome (one case), tumor (one case), os odontoideum (two cases), and pseudarthrosis/other (one case), who underwent OMI Loop—assisted occipitocervical reconstruction. The mean follow-up period was 25.4 months (range 6–60 months). A solid reconstruction was achieved in 29 of 30 cases; there was only one case of hardware failure requiring reoperation. Noncritical hardware failure occurred in two patients in whom partial occipital screw backout occurred but did not necessitate reoperation. There were no perioperative neurological complications. One patient (3.3%) experienced a delayed postoperative worsening of myelopathy at 1 year that resolved with further surgery. Postoperatively, in 66.6% of patients the degree of myelopathy remained stable (as measured by American Spinal Injury Association [ASIA] scores), whereas 30% improved by one or more ASIA grade. The rate of osseous fusion was 96.6% at a mean follow-up period of 25.4 months. Conclusions. The authors found that the OMI Loop is a versatile precontoured occipitocervical fixation device that can be applied to a wide range of CCJ lesions. It provides excellent immediate rigid fixation of the CCJ, a high rate of osseous fusion, and a low rate of hardware failure.