Magnetic Resonance Imaging Clarity of the Bryan®, Prodisc-C®, Prestige LP®, and PCM® Cervical Arthroplasty Devices

Abstract

Preoperative and postoperative magnetic resonance imaging scans of 20 patients who had undergone cervical arthroplasty were assessed for imaging quality. Five cases each of the Bryan (Medtronic Sofamor Danek, Memphis, TN), Prodisc-C (Synthes Spine, Paoli, PA), Prestige LP (Medtronic Sofamor Danek), and PCM devices (Cervitech, Rockaway, NJ) were analyzed. Six blinded spinal surgeons scored twice sagittal and axial T2-weighted images using the Jarvik 4-point scale. Statistical analysis was performed comparing quality before surgery and after disc implantation at the operated and adjacent levels and between implant types. RESULTS.: Moderate intraobserver and interobserver reliability was noted. Preoperative images of patients in all implant groups had high-quality images at operative and adjacent levels. The Bryan and Prestige LP devices allowed satisfactory visualization of the canal, exit foramina, cord, and adjacent levels after arthroplasty. Visualization was significantly impaired in all PCM and Prodisc-C cases at the operated level in both the spinal canal and neural foramina. At the adjacent levels, image quality was statistically poorer in the PCM and Prodisc-C than those of Prestige LP or Bryan. CONCLUSIONS.: Postoperative visualization of neural structures and adjacent levels after cervical arthroplasty is variable among current available devices. Devices containing nontitanium metals (cobalt-chrome-molybdenum alloys in the PCM and Prodisc-C) prevent accurate postoperative assessment with magnetic resonance imaging at the surgical and adjacent levels. Titanium devices, with or without polyethylene (Bryan disc or Prestige LP), allow for satisfactory monitoring of the adjacent and operated levels. This information is crucial for any surgeon who wishes to assess adequacy of neural decompression and where monitoring of adjacent levels is desired.

Quantification of metal‐induced susceptibility artifacts associated with ultrahigh‐field magnetic resonance imaging of spinal implants

“…Although titanium alloy is inferior in strength, it is considered to be suitable for postoperative follow-up using MRI because it produces smaller artifacts due to its lower magnetic susceptibility. As reported for 1.5-T, 14,15 we found that titanium alloy was also advantageous for reducing artifacts, even at 7 T.…”

A case of cervical metastases in a patient with preexisting cervical disc replacement and fusion after 2-year symptom-free interval: when do we need interdisciplinary diagnostics?

“…Especially after a symptom-free interval of 2 years recurrent cervical symptoms are often believed to result from vertebrogenic causes. Metal artifacts complicate the evaluation of MRI and CT scans 15,16,17. The absence of neurological deficits demands a nonsurgical treatment leading to a successful outcome in most patients 6.…”

“…The clarity of MRI after cervical arthroplasty has been reported. Titanium devices allow for satisfactory imaging of the adjacent and index levels, but non-titanium devices (cobalt-chrome-molybdenum alloys) create significant image distortion, preventing accurate imaging at the index and adjacent levels 2. More recently, it has been demonstrated that magnet strength affects the artifact from cobalt-chrome alloys.…”

The future of spine surgery: New horizons in the treatment of spinal disorders

“…In a study evaluating the ability to visualize the spinal canal and adjacent segments after cervical disc arthroplasty, only the Bryan (Medtronic) and Prestige LP (Medtronic) allowed for adequate visualization. [54] The artifact produced by these implants can be circumvented with the use of non-ferromagnetic biomaterials allowing for postoperative imaging and evaluation in the future. Polymers and ceramics may also be employed in the design of future intervertebral disc prostheses.…”