Long-term outcome data for a low-profile artificial disc replacement (Prestige LP, Medtronic) has indicated that the device, when used at two levels, is associated with a higher rate of overall success than is anterior cervical discectomy and fusion (ACDF) at 84 months. Additionally, at this time point, the Prestige LP was associated with fewer implant/surgical procedure-related adverse events and fewer second surgical procedures.
Writing in the Journal of Neurosurgery: Spine, Todd H Lanman (Los Angeles, USA) and others commented that a previous study showed that the artificial disc was associated with greater overall success than was ACDF in patients with degenerative cervical spine disease at 24 months. Overall success was defined as a postoperative improvement in Neck Disability Index (NDI) score of at least 15 points, no worsening of neurological status, and no serious implant or surgical-procedure related adverse events.
The aim of the present study, the authors wrote, was to assess the “long-term effectiveness and safety of the Prestige LP artificial disc replacement at two contiguous levels by comparing outcomes up to 84 months postoperatively with those for the ACDF treatment group.”
In the prospective randomised controlled trial, 209 patients underwent disc replacement and 188 underwent ACDF. According to Lanman et al, the observed overall success rate (the primary endpoint) was higher for the disc than for ACDF at 36, 60, and 84 months: 81.6% vs. 70.5%, 79.6% vs. 65.9%, and 78.6% vs. 62.7% (posterior probability of superiority [PPS]; 99.8%), respectively.
The authors report: “By 84 months, 87% of artificial disc replacement patients met criteria for NDI success compared with 75.6% of the ACDF group. A similar difference was shown at 84 months for the neurological success (91.6% vs. 82.1%; PPS=99%).”
Furthermore, cumulative through to 84 months, treatment using the artificial disc was associated with a statistically lower rate of any type of serious adverse events and a lower rate of possibly device-related adverse events.
“The rates of a secondary surgery at the treated levels through 84 months were 4.2% and 14.7% for the artificial disc replacement and ACDF groups, respectively, a statistically significant difference favouring the artificial disc replacement group,” Lanman et al reported.
The authors conclude that these long-term findings show that the Prestige LP artificial cervical disc to be “an effective alternative to standard fusion treatment in patients with degenerative disc disease associated with intractable radiculopathy or myelopathy at two adjacent levels of the cervical spine.”
This article first appeared in issue 44 of Spinal News International with the headline “Two-level artificial disc replacement “an effective alternative” to fusion at 84 months”.