Objectives: To investigate clinical effects and manual operational point of Bryan cervical disc prosthesis in Asian, to observe the stability and range of movement (ROM) postoperatively.
Methods: Bryan disc prosthesis replacement applied in 8 cases (10 levels) of cervical spondylotic myelopathy (CSM). Clinical (JOA grade and Odom's scale) and radiological (X-ray of bending, extending; left and right bending position) follow-up was performed 3 months postoperatively, (mean follow-up 3.6 month). Systemic radiographic study about stability and ROM of replaced level post operationally were measured. CT or MRI scan were applied in all cases 3 months postoperatively to find out the excursion of the prosthesis and heterotopic-ossification in the replaced levels.
Results: At least 3 months follow-up were done in all this patients. There was no complication. Improvement in all of 8 patients according to the Odsm's scale. JOA score increased from average 8.8 to 15.8. There was no prosthesis subsidence or excursion. Replaced segment achieved stability and restored partial of normal ROM, 4.75 degrees (3.8 degrees approximately 5.8 degrees ) in flex and extension position and 3.38 degrees (2.3 degrees approximately 4.4 degrees ), 3.13 degrees (2.5 degrees approximately 4.1 degrees ) in left and right bending position. No obvious loss of lordosis was found. CT or MRI follow-up show excursion (<2 mm) in 1/10 levels; (<2 mm excursion <4 mm) in 1/10 levels, and no heterotopic ossification in the replaced levels.
Conclusions: Byran cervical disc prosthesis restored motion to the level of the intact segment in flexion-extension and lateral bending in post operational 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 in Asian.