ObjectiveTo evaluate the mid-term clinical and radiological results of dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease in Chinese population.MethodsBetween April 2010 and June 2011, 25 patients with single-segmental degenerative cervical disc disease underwent DCI replacement. Visual Analogue Scale (VAS), Japanese Orthopaedic Association (JOA) scores, Neck Disability Index (NDI) and 36-Item Short Form Health Survey Questionnaires (SF-36) were used for evaluation of neurological function and pain severity, before and after operation, and during follow-up period. Radiographic evaluation included range of motion (ROM) of C2–7, surgical segments and adjacent level, intervertebral height of the surgical segments, migration, subsidence of the implant and heterotopic ossification (HO).ResultsThe mean follow-up period was 72.3 months (ranged from 68 to 78 months). The VAS, JOA, NDI, and SF-36 mental and physical component summaries improved significantly after surgery (P<0.05) and remained stable over the whole observation period. The ROM (flexion/extension) and intervertebral height at the level treated with DCI remained at the first 2 years and partly reduced at the final follow-up. ROM for C2–7 and adjacent levels maintained during the follow-up period. DCI subsidence was observed in 11 segements, and 9 segements appeared heterotopic ossification.ConclusionsClinical efficacy of DCI arthroplasty improves and maintaines during the mid-to-long period of follow-up. HO formation is a common phenomenon, leading a dramatic decrease of ROM at index level and recurrence of neurological symptoms. Rate of implant subsidence and migration is relatively high, leaving a potential risk of symptom at index level and adjacent segment degeneration. It suggests that for patients with degenerative cervical disc disease, total disc replacement or anterior cervical discectomy and fusion is still the first choice instead of DCI arthroplasty.