title: Clinical and Radiologic Findings After Multilevel Cervical Total Disk Replacement: Defining Radiologic Changes to Predict Surgical Outcomes.
abstract: OBJECTIVE
  This study compared the radiologic parameters between preoperation and postoperation for patients who underwent multilevel cervical total disk replacement (MCTDR) and assessed which parameters were related to successful clinical outcomes after MCTDR.
  
  
  METHODS
  The study included a consecutive series of 24 patients who were treated with MCTDR following the diagnosis of multilevel cervical disk herniation or stenosis. Numeric Rating Scale, C2-7 sagittal vertical axis, range of motion (ROM) of C2-7 segment, and total disk replacement (TDR) implanted levels were evaluated at pre- and post-TDR. These parameters were compared between patients who experienced successful and unsuccessful pain relief.
  
  
  RESULTS
  Numeric Rating Scale scores were reduced while C2-7 sagittal vertical axis improved significantly after MCTDR. C2-7 flexion was significantly decreased (P < 0.05), while its extension showed trends toward considerable (P = 0.088) increase, thereby maintaining original C2-7 ROM without statistical significance. TDR flexion was decreased (P < 0.05), while its extension changes were stationary, consequently resulting in a significant decrease in TDR ROM (P < 0.05). The unsuccessful group showed markedly reduced ROM and lack of ROM angular change maintenance at both the C2-7 and MCTDR levels (P < 0.05) compared with the successful group.
  
  
  CONCLUSIONS
  MCTDR was effective in reducing pain and improving cervical lordosis in patients with multilevel cervical disk herniation or stenosis. Despite a significant decrease in the flexion angle, it could maintain C2-7 ROM presumably by compensating with C2-7 extension angle increase. Clinical success after MCTDR was crucially related to retaining original C2-7 ROM and minimizing ROM angular changes at both the C2-7 and MCTDR levels.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Wooridul Spine Hospital, Seoul, Korea.
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Kyung Hee University Medical Center, Seoul, Korea. Electronic address: moo9924@khu.ac.kr.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Wooridul Spine Hospital, Seoul, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007405:Intervertebral Disc Displacement / Q000175:diagnosis* / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013130:Spinal Stenosis / Q000175:diagnosis* / Q000601:surgery*; D059145:Total Disc Replacement / Q000295:instrumentation / Q000379:methods*
keywords: Angular change; Clinical success; Lordosis; Multilevel cervical total disk replacement; Numeric Rating Scale; Range of motion