Persistent axial neck pain after cervical disc arthroplasty: a radiographic analysis

Background Context There is very little literature examining optimal radiographic parameters for placement of cervical disc arthroplasty (CDA), nor is there substantial evidence evaluating the relationship between persistent postoperative neck pain and radiographic outcomes. Purpose We set out to perform a single-center evaluation of the radiographic outcomes, including associated complications, of CDA. Design This is a retrospective review. Patient Sample Two hundred eighty-five consecutive patients undergoing CDA were included in the review. Outcome Measures The outcome measures were radiological parameters (preoperative facet arthrosis, disc height, CDA placement in sagittal and coronal planes, heterotopic ossification [HO] formation, etc.) and patient outcomes (persistent pain, recurrent pain, new-onset pain, etc.). Methods We performed a retrospective review of all patients from a single military tertiary medical center from August 2008 to August 2012 undergoing CDA. Preoperative, immediate postoperative, and final follow-up films were evaluated. The clinical outcomes and complications associated with the procedure were also examined. Results The average radiographic follow-up was 13.5 months and the rate of persistent axial neck pain was 17.2%. For patients with persistent neck pain, the rate of HO formation per level studied was 22.6%, whereas the rate was significantly lower for patients without neck pain (11.7%, p=.03). There was no significant association between the severity of HO and the presence of neck pain. Patients with a preoperative diagnosis of cervicalgia, compared to those without cervicalgia, were significantly more likely to experience continued neck pain postoperatively (28.6% vs. 13.1%, p=.01). There were no differences in preoperative facet arthrosis, pre- or postoperative disc height, segmental range of motion, or placement of the device relative to the posterior edge of the vertebral body.However, patients with implants more centered between the uncovertebral joints were more likely to experience posterior neck pain (p=.03). Conclusions We found that posterior axial neck pain is relatively frequent after CDA, and patients with persistent neck pain were significantly more likely to have preoperative cervicalgia and develop HO postoperatively. We also found that patients with implants that were placed off-centered were less likely to also complain of neck pain, although the reasons for this finding remain unclear.