The NECK trial: Effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; a double-blinded randomized controlled trial.

BACKGROUND: Motion preserving anterior cervical disc arthroplasty (ACDA) in patients with cervical radiculopathy was introduced to prevent symptomatic adjacent disc degeneration as compared with anterior cervical discectomy and fusion (ACDF). Prior reports suggest that ACDF is not more effective than anterior cervical discectomy (ACD) alone for the treatment of cervical radiculopathy.

PURPOSE: To evaluate whether patients with cervical radiculopathy due to a herniated disc benefit more from undergoing ACDA, ACDF, or ACD in terms of clinical outcome measured by the neck disability index (NDI).

STUDY DESIGN: Double-blinded randomized controlled trial.

METHODS: One hundred-nine patients with one level herniated disc were randomized to one of the following treatments: ACDA, ACDF with intervertebral cage, ACD without fusion. Clinical and radiological outcome was measured by NDI, Visual Analogue Scale (VAS) neck pain, VAS arm pain, SF36, EQ-5D, patients' self-reported perceived recovery, radiographic cervical curvature, and adjacent segment degeneration parameters at baseline and until two years after surgery. BBraun Medical paid €298.837 to cover the costs for research nurses.

RESULTS: The NDI declined from 41 to 47 points at baseline to 19 ± 15 in the ACD group, 19 ± 18 in the ACDF group, and 20 ± 22 in the ACDA group after surgery (p=.929). VAS arm and neck pain declined to half its baseline value and decreased below the critical value of 40 mm. Quality of life, measured by the EQ-5D, increased in all three groups. Adjacent segment degeneration parameters were comparable in all three groups as well. No statistical differences were demonstrated between the treatment groups.

CONCLUSIONS: The hypothesis that ACDA would lead to superior clinical outcome in comparison to ACDF or ACD could not be confirmed during a 2-year follow-up time period. Single level ACD without implanting an intervertebral device may be a reasonable alternative to ACDF or ACDA.