Result of the arc of movement of lower cervical spine after seven years of arthroplasty

OBJECTIVE: To quantify the mobility of the lower cervical spine after seven years of total cervical disc replacement at two levels. METHOD: This clinical study was designed randomly and prospectively at the spine surgery center at the Hospital Nossa Senhora das Graças, in Canoas, RS-Brazil and at the Hospital Don João Becker, in Gravataí, RS-Brazil. Seventeen patients were included in the study that was designed to compare the data obtained from annual and sequential manner until the end of seven years. A comparison was made with the prior range of motion (ROM) of each patient. All patients were diagnosed with not tractable symptomatic cervical degenerative disc disease with two adjacent levels between C-3 and C-7. RESULTS: A total of patients underwent TDR in two levels and at the end of seven years, only one patient was lost to follow-up. The pre and postoperative ROM was the same in the first three years however after the fourth year there was a gradual decline with a loss of 12% of preoperative ROM in flexion, 21% in extension and 23% in the right and left lateral bending at the end of seven years. CONCLUSIONS: The clinical outcome of this study is evidence level IV in evaluating the ROM for Moby-C(r) for TDR in two adjacent levels at the lower cervical spine. These results show that the ROM is maintained during the first three years, gradually declining after that.