Clinical outcomes of BRYAN cervical disc arthroplasty: a prospective, randomized, controlled, multicenter trial with 24-month follow-up.

STUDY DESIGN/SETTING: Prospective, randomized, 3-center, clinical trial.

OBJECTIVE

To prospectively compare the outcomes of cervical arthroplasty with the BRYAN Cervical Disc Prosthesis (Medtronic Sofamor Danek, Inc, Memphis, TN) to anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Surgical treatment of cervical disc pathology commonly involves techniques that employ discectomy and fusion (ACDF). This "gold-standard" technique has demonstrated good clinical and radiographic outcomes. Common adverse effects of this procedure are associated with the adjacent level degeneration and bone-graft harvest. Several investigators have independently reported successful short-term outcomes with the BRYAN Cervical Disc Prosthesis. In addition, a significant body of knowledge has been collected regarding the wear patterns and adjacent level effects of this device in human and animal models.

METHODS

As part of an FDA IDE trial, 3 centers collected prospective outcomes data on 115 patients randomized in a 1:1 ratio to ACDF (Control group) or arthroplasty with the BRYAN Cervical Disc Prosthesis (Investigational group).

RESULTS

Demographic and surgical data were generally similar in the 2 populations. Outcomes data collected at routine postoperative intervals for 24 months demonstrated that the Investigational group had statistically significant (P<0.05) improvements as assessed by the Neck Disability Index, the Neck Pain Score, and SF-36 Physical component scores. The improvement in the Mental Component Subscore values for the BRYAN and control groups was equivalent at 24 months (P=0.055). Arm pain relief was similar in both groups (P=0.152). During the course of the 2-year follow-up, 4 patients in the Control group required surgical intervention and 3 patients in the Investigational group required ACDF for adjacent level disease.

CONCLUSIONS

At 24 months, cervical arthroplasty with the BRYAN Cervical Disc Prosthesis compares favorably with ACDF as defined by standard outcomes scores.