PCM cervical disc continues to maintain motion at five years


According to a study presented at the 20th International Meeting on Advanced Spine Techniques (IMAST; 10–13 July, Vancouver, Canada), the PCM cervical disc (NuVasive) is associated with maintained motion and good clinical outcomes in patients with degenerative disc disease at five years. The disc is also associated with a significantly higher rate of neck disability index (NDI) success than anterior cervical discectomy and fusion (ACDF) with allograft and plate. 

The study, which was presented by lead author Frank Phillips (Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, USA), was a prospective, multicentre  study that compared the clinical outcomes of patients with degenerative disc disease at one level (C3–T1) and neurological symptoms who were treated with the PCM disc with those of patients treated with ACDF. Phillips reported: “Outcomes measures included NDI, neurological success, overall success (composite primary endpoint), range of motion, and the rate of secondary surgeries at the operative level.” He explained that that “NDI success” was defined as a minimum 20% improvement over baseline and that neurological success was defined as a maintenance or improvement in neurological status over baseline.

At five years, patients who had received the disc (160 overall) had a significantly lower average NDI score than patients who received ACDF (124 overall)—20.4 vs. 28.5, respectively; p=0.001. Additionally, PCM patients also had a significantly greater reduction in NDI score from baseline compared with ACDF patients (34.4 vs. 26.8, respectively; p=0.003) and a significantly higher rate of NDI success (84.7% vs. 73.6%, respectively; p=0.025). However, there were no significant differences in the rate of neurological success (92.1% of PCM patients vs. 88.2% of ACDF patients; p=0.305) or in the rate of secondary surgeries (7.9% for PCM vs. 7.4% for ACDF; p=0.854) between groups. Phillips noted: “Overall success favoured PCM, but the rates were not statistically significant (66.9% of PCM patients vs. 57.3% of ACDF patients; p=0.108).” He added that the average range of motion was 5.3 degrees (range 0–16.1) for PCM and 0.5 degrees for ACDF (0–4.1), stating that adjacent level range of motion was generally consistent with the two-, three-, and four-year results for both groups.

Concluding, Phillips noted: “PCM cervical disc maintained motion and continued to achieve clinical outcomes at least equivalent to ACDF.” He told Spinal News International: “This study adds to the growing body of level one evidence that cervical arthroplasty is a highly successful treatment option in appropriately selected patients”.