title: Transvertebral anterior cervical foraminotomy: midterm outcomes of clinical and radiological assessments including the finite element method.
abstract: OBJECTIVE
  The aim of this study was to compare the clinical features, radiological changes, biomechanical effects, and efficacy in patients treated by transvertebral anterior foraminotomy. Preservation of segmental motion and avoidance of adjacent segment degeneration are theoretical advantages of transvertebral anterior foraminotomy. In practice, this procedure is minimally invasive and has shown good clinical results, especially in patients with unilateral cervical radiculopathy.
  
  
  METHODS
  We conducted a retrospective minimum 2-year follow-up study of the cervical spine of patients treated by transvertebral anterior foraminotomy at our institution. Radiological outcomes, which were estimated by measuring disc and functional spinal unit heights, and the angle and range of motion (ROM) from C2 to C7 of the functional spinal unit and adjacent segments were evaluated. Furthermore, a three-dimensional finite element method was used to biomechanically analyze the strength of the postoperative vertebral body.
  
  
  RESULTS
  Between 2004 and 2009, 34 patients underwent surgery. The improvement rate was 94.2 %. The average flexion-extension ROM from C2 to C7 was 36.6 ± 16.6°. On plain radiographs, the disc height and ROM and height of the functional spinal unit in the operated segment were not significantly decreased relative to the preoperative levels. The finite element method also revealed that there was no difference in strength between the pre- and postvertebral bodies.
  
  
  CONCLUSIONS
  These results demonstrate that biomechanical stability was achieved. Transvertebral anterior cervical foraminotomy did not limit motion in the operated and adjacent segments and did not cause a significant decrease in disc and vertebral heights after surgery.
authors: Department of Neurosurgery, Nagoya University School of Medicine, Nagoya, Aichi, 466-8550, Japan, umebayad@gmail.com.
authors: Daisuke
authors: D
authors: Umebayashi
authors: Masahito
authors: M
authors: Hara
authors: Yasuhiro
authors: Y
authors: Nakajima
authors: Yusuke
authors: Y
authors: Nishimura
authors: Toshihiko
authors: T
authors: Wakabayashi
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D020342:Finite Element Analysis; D005500:Follow-Up Studies; D059526:Foraminotomy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013131:Spine / Q000000981:diagnostic imaging / Q000601:surgery
references: J Bone Joint Surg Br. 1969 May;51(2):225-37
references: 4890317
references: J Neurosurg. 1976 Aug;45(2):203-10
references: 939979
references: Spine (Phila Pa 1976). 2000 Apr 15;25(8):905-9
references: 10767800
references: Br J Neurosurg. 1996 Jun;10(3):261-6
references: 8799536
references: J Neurosurg. 2003 Mar;98(2 Suppl):121-5; discussion 125
references: 12650394
references: Surg Neurol. 2000 Apr;53(4):340-6; discussion 346-8
references: 10825519
references: J Bone Joint Surg Am. 1999 Apr;81(4):519-28
references: 10225797
references: Clin Orthop Relat Res. 1989 Sep;(246):92-9
references: 2766628
references: J Neurosurg. 1996 Feb;84(2):155-60
references: 8592215
references: Br J Neurosurg. 1999 Oct;13(5):474-9
references: 10627778
references: J Spinal Disord Tech. 2009 Aug;22(6):408-12
references: 19652566
references: Surg Neurol. 2009 Jun;71(6):677-80, discussion 680
references: 18786707
references: Clin Orthop Relat Res. 1992 Nov;(284):10-3
references: 1395278
references: J Bone Joint Surg Am. 1958 Jun;40-A(3):607-24
references: 13539086
references: Eur Spine J. 2007 Sep;16(9):1387-93
references: 17203272
references: J Neurosurg. 1976 Sep;45(3):284-91
references: 781189
references: J Neurosurg. 2003 Mar;98(2 Suppl):126-30
references: 12650395
references: Spine (Phila Pa 1976). 1984 Oct;9(7):667-71
references: 6505833
references: J Spinal Disord. 2000 Feb;13(1):16-21
references: 10710143