Background: Preservation of segmental motion and avoidance of adjacent segment degeneration are common theoretical advantages of cervical arthroplasty and ACF. In patients with unilateral cervical radiculopathy, both procedures have shown good clinical results; but there are currently no proven comparative biomechanical results. This study was designed to compare the biomechanical effect of cervical arthroplasty and ACF and to propose optimal inclusion criteria for each surgery.
Methods: Among the patients with unilateral cervical radiculopathy, 15 patients who underwent arthroplasties using the Bryan disk (Medtronic Sofamor Danek, Memphis, TN) and 13 patients who underwent ACFs were retrospectively analyzed. A radiological assessment and comparative analysis of the biomechanical results (sagittal alignment, ROM, and disk height) between the 2 procedures were performed.
Results: Both procedures showed similar but contrary biomechanical results, with the exception of the disk height. Anterior cervical foraminotomy has been shown to restrict motion in the segmental and adjacent segment motion and a tendency toward restoration of lordosis. Anterior cervical foraminotomy caused a significant decrease in disk height after surgery, whereas arthroplasty caused no change in height. The restoration of disk height was achieved by arthroplasty, especially in patients with spondylotic radiculopathy.
Conclusions: In unilateral cervical radiculopathy, arthroplasty and ACF provided favorable clinical and radiological outcomes. However, we should understand the different biomechanical backgrounds resulting in common advantages. To achieve the fundamental goal of the procedures, the patients' biomechanical abnormalities should be elucidated and treated by the optimal procedure.