Superiority of the Bryan(®) disc prosthesis for cervical myelopathy: a randomized study with 3-year followup.

BACKGROUND

The current standard of care for cervical myopathy is anterior discectomy and fusion (ACDF). Although well tolerated in the short term, this treatment might ultimately result in progressive degeneration of adjacent motion segments. Artificial disc arthroplasty offers the theoretical advantage of preservation of motion at the operative level with consequent stress reduction at adjacent levels.

QUESTIONS/PURPOSES: We compared function, radiographic measures, and incidence of complications at 3-year followup after cervical disc arthroplasty with the Bryan(®) prosthesis and ACDF in patients with cervical myelopathy.

PATIENTS AND

METHODS

Eighty-three patients with cervical myelopathy were randomized to undergo arthroplasty with implantation of a Bryan(®) cervical disc prosthesis (n = 41) or ACDF (n = 42). Patients were assessed preoperatively to 3 years postoperatively using the modified Odom's criteria, Japanese Orthopaedic Association scale, SF-36, and Neck Disability Index. ROM, stability, and subsidence of the prostheses were evaluated radiographically.

RESULTS

Patients who received the Bryan(®) prosthesis scored significantly better in three of the four functional assessment methods used (Japanese Orthopaedic Association scale, SF-36, and Neck Disability Index). ROM was retained by the patients in the Bryan(®) group but not in the patients in the ACDF group. Patients in the Bryan(®) group had fewer complications, primarily because dysphagia occurred in only one patient in the Bryan(®) group but in seven patients in the ACDF group. Other complications included pseudarthrosis in three patients in the ACDF group and one patient had spontaneous fusion, one had deep vein thrombosis, and one had heterotopic ossification in the Bryan(®) group.

CONCLUSIONS

Bryan(®) cervical disc arthroplasty appears reliable and effective in the treatment of cervical myelopathy.

LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of the levels of evidence.