title: Cervical myelopathy after cervical total disc arthroplasty: case report and literature review.
abstract: METHODS
  Case report and literature review.
  
  
  OBJECTIVE
  This article reports 2 cases in which the patients accepted revision surgery after cervical total disc arthroplasty (CTDA) because of iatrogenic neurological injury.
  
  
  BACKGROUND
  CTDA has been increasingly investigated to treat cervical degenerative disc disease. However, there are limited reports focused on its complications, especially the neurological complications after the procedure.
  
  
  METHODS
  A 52-year-old man underwent total disc arthroplasty for C5-C6, but immediately after surgery, he experienced paralysis of his upper and lower limbs. Radiographical images indicated residual compression to the spinal cord in the level of C5-C6. Another patient, a 60-year-old man, underwent total disc arthroplasty for C4-C5. Afterward, he experienced severe neck pain and paralysis of upper and lower limbs. He was unresponsive to conservative treatments; thus, a laminectomy was performed 3 months later. However, little improvement was observed. Radiographical images indicated kyphosis and spinal cord compression at the level of C4-C5. Furthermore, both cases showed a high signal in the spinal cord by T2-weighted magnetic resonance image, suggestive of spinal cord injuries.
  
  
  RESULTS
  Revision surgeries were performed in both cases. Cervical implants were first removed by the anterior approach, and fusion was then performed after a complete decompression. Motor examination of the patient in case 1 showed grade 3 strength in both of his hands and feet 6 months after revision surgery. In case 2, the patient's severe neck pain was resolved at the early postoperative stage. Motor examination showed grade 1 strength in both of his hands and feet 3 months after revision surgery.
  
  
  CONCLUSIONS
  On the basis of presented cases and other reports, the surgical goals in these patients were prioritized as follows: (1) safe and adequate neurological decompression and (2) establishment and maintenance of cervical sagittal balance. Moreover, a criterion for selecting patients undergoing CTDA needs to be established in order to reduce the occurrence of neurological complications associated with the procedure.
authors.affiliation: Department of Orthopedics, Second Military Medical University-Affiliated Changzheng Hospital, Shanghai, People's Republic of China. aspirin_cj@yahoo.com.cn
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Xinwei
authors.initials: X
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Yuan
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Wan
mesh_terms: D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D013118:Spinal Cord Diseases / Q000175:diagnosis* / Q000601:surgery*; D059145:Total Disc Replacement / Q000009:adverse effects*