Clinical report of cervical arthroplasty in management of spondylotic myelopathy in Chinese.

OBJECTIVES: To investigate clinical effects and manual operational point of Bryan cervical disc prosthesis in Chinese, to observe the stability and range of movement (ROM) post-operatively.

METHODS AND MATERIALS: From 2003,12 to 2005,12, Bryan disc prosthesis replacement applied in 83 cases (102 levels) of cervical spondylotic myelopathy (CSM) after anterior decompression in our hospital. Clinical (JOA grade and Odom's scale) and radiological (X-ray of flexion, extension; left and right bending position) follow-up was performed. Systemic radiographic study about stability and ROM of replaced level post operationally were measured. CT or MRI scans were applied in all cases to evaluate the signs of the prosthesis deflexion and hetero-ossification in the replaced levels.

RESULTS: At least 12 months follow-up were done in 65/83 of these patients. All of 83 patients were improved according to Odsm's scale. JOA score increased from average 8.7 to 15.5. There was no prosthesis subsidence. Replaced segment achieved stability and restored partial of normal ROM 4.73 degrees (3.7 degrees -5.9 degrees ) early postoperation and 8.12 degrees (5.8 degrees -13.6 degrees ) more than 12 months postoperation in flex and extension position. No obvious loss of lordosis was found. CT or MRI follow-up shows position deflexion of the prosthesis metal endplates (<1.5 mm) in 14/77 levels and (1.5-3 mm) in 4/77. heter-ossification was found in the replaced levels only in 2 cases.

CONCLUSION: Byran cervical disc prosthesis restored motion to the level of the intact segment in flexion-extension and lateral bending in post-operative images. At the same time, it can achieve good anterior decompression treatment effect and immediate stability in replaced 1 or 2 levels, and which is a new choice for the treatment of CSM.