Abstract
BackgroundCervical disc arthroplasty (CDA) has been demonstrated in clinical trials as an effective and safe treatment for patients diagnosed with radiculopathy and/or myelopathy. However, the current CDA indication criteria based on the preoperative segmental range of motion (ROM), comprise a wide range of variability. Although the arthroplasty level preserved ROM averaged 7°-9° after CDA, there are no clear guidelines on preoperatively limited or excessive ROM at the index level, that could be considered as suitable for CDA in any given trials.MethodsPatients who underwent CDA between January 2008 to October 2018 using Prestige-LP discs in our hospital, were reviewed retrospectively. They were divided into the small-ROM (≤5.5°) and the large-ROM (> 12.5°) groups according to preoperatively index-level ROM. Clinical outcomes, including the Japanese Orthopedics Association (JOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) scores, were evaluated. Radiological parameters, including cervical lordosis, disc angle (DA), global and segmental ROM, disc height (DH), and complications were measured.ResultsOne hundred and twenty-six patients, with a total of 132 arthroplasty segments were analyzed. There were 64 patients in the small-ROM and 62 in the large-ROM group. There are more patients diagnosed with cervical spondylosis in the small-ROM than in the large-ROM group (P=0.046). Patients in both groups had significantly improved in JOA, NDI, and VAS scores after surgery, but the intergroup difference was not significant. Patients in the small-ROM group increased dramatically in cervical lordosis, global and segmental ROM postoperatively (P < 0.001). However, global and segmental ROM paradoxically decreased in the large-ROM group postoperatively (P < 0.001). Patients in the small-ROM group had lower DH preoperatively (P=0.012), and a higher rate of heterotopic ossification (HO) postoperatively (P=0.037).ConclusionPatients with preoperatively limited or excessive segmental ROM could achieve satisfactory clinical outcomes at 3 years postoperatively. Patients with limited segmental ROM had more, and severe HO and significantly increased segmental mobility, which decreased in patients with excessive segmental ROM after surgery.
Effect of preoperative segmental range of motion on patient outcomes in cervical disc arthroplasty