Lumbar Disc Arthroplasty XRay vs. CT Imaging

With the growing availability of total disc arthroplasty in place of fusion, the authors of the study chose to study the accuracy of xrays as opposed to comupted tomography (CT) scan in estimating placement of the implant. At the time of the study, most were evaluated with xray only.

Correct placement of an implant is critical in optimal long-term function. Malplacement may cause premature implant wear, implant loosening, and stresses on adjacent segments and facet joints.

Thirty-six patients who had undergone lumbar total disc arthroplasty were studied. Imaging is used to assess interpedicular midline placement as well as vertebral body placement. Anteroposterior (AP) and lateral views with plain Xrays were obtained. These were compared to CT scans. The authers found that there was no significant difference between xray and CT scans when evaluating for midline malplacement. However, the authors felt the correlation between xray and CT for vertebral body penetration was poor. Therefore, they recommend early postoperative CT.