ObjectiveTo discuss the safety and effectiveness of combined dynamic cervical implant (DCI) and Cage fusion in the treatment of two-level cervical disc protrusion. MethodsBetween September 2009 and June 2011, 16 cases of two-level cervical disc protrusion were treated with combined DCI and Cage fusion. Of 16 cases, 10 were male and 6 were female, with a mean age of 44.1 years (range, 37-64 years) and with a mean disease duration of 5.1 years (range, 2-8 years), including 8 cases of cervical myelopathy, 5 cases of nerve root cervical myelopathy, and 3 cases of mixed cervical myelopathy. Radiological results indicated degenerative intervertebral discs and compressed never root or spinal cord. Involved discs included C3,4 and C4,5 (1 case), C3,4 and C5,6(5 cases), C4,5 and C5,6 (3 cases), C4,5 and C6,7 (5 cases), and C5,6 and C6,7 (2 cases). The neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and visual analogue scale (VAS) were used to evaluate the neurological function and pain relief. The stabilities and activities of involved segments, intervertebral fusion, and displacement of Cages were observed during follow-up. ResultsPrimary healing of incisions was obtained in all cases; no complication of hematoma, infection, cerebrospinal fluid leakage, or neural function damage occurred. All 16 patients were followed up 18 months on average (range, 6-36 months). The cervical X-ray results indicated that the activities of involved segments was (7.8±3.1)°, showing no significant difference (t=0.655, P=0.132) when compared with preoperative value [(7.3±2.6)°]. No implant loosening was observed; slight heterotopic ossification occurred in 1 patient at the posterior rim of intervertebral space. No cage loosening or sinking was seen, and good fusion was achieved. The mean time of fusion was 4.5 months (range, 3-8 months). NDI, JOA, and VAS scores at last follow-up (18.3±5.1, 15.7±1.5, and 3.4±1.8 respectively) were significantly improved (t=2.131, P=0.016; t=3.126, P=0.024; t=6.102, P=0.038) when compared with preoperative scores (49.6±11.3, 12.8±2.0, and 6.7±1.2 respectively). ConclusionA combination of DCI and intervertebral Cage fusion has satisfactory early effectiveness in treatment of two-level cervical intervertebral protrusion for maintaining the stability and activity of cervical vertebrae.
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.