title: C1-C2 stabilization by Harms arthrodesis: indications, technique, complications and outcomes in a prospective 26-case series.
abstract: BACKGROUND
  C1-C2 arthrodesis is a surgical challenge due to the proximity of neurovascular structures (vertebral arteries and spinal cord) and the wide range of motion of the joint, hampering bone fusion. A variety of techniques have been successively recommended to reduce anatomic risk and improve results in terms of biomechanical stability and fusion rates. Recently, Harms described a new technique using polyaxial screws in the C1 lateral masses and C2 pedicles.
  
  
  METHODS
  The present study reports our experience in a consecutive series of 26 patients operated on by C1-C2 arthrodesis using the Goel and Harms technique, and details technical aspects step by step. Routine systematic immediate postoperative CT and 6-month CT controlled screw positioning and assessed fusion. Follow-up was at least 1 year, except in 2 cases (10 months).
  
  
  RESULTS
  Twenty-six patients with a mean age of 57 years were included. Indications comprised: C2 non-union (n=11), C1-C2 fracture and/or dislocation (n=11), inflammatory pathology (n=2) and tumoral pathology (n=2). The results showed the technique to be reliable (no neurovascular complications and 85% of screws with perfect positioning) and an excellent rate of fusion (100% at 6 months).
  
  
  CONCLUSIONS
  Anatomic and biomechanical considerations, combined with the present clinical and radiological outcomes, indicate that Goel and Harms fusion is to be considered the first-line attitude of choice for posterior C1-C2 arthrodesis.
  
  
  METHODS
  Level IV prospective study.
authors.affiliation: Service de Neurochirurgie C et Chirurgie du Rachis, Hôpital Pierre-Wertheimer, GHE, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: P
authors.initials: P
authors.lastname: Bourdillon
authors.affiliation: Service de Neurochirurgie C et Chirurgie du Rachis, Hôpital Pierre-Wertheimer, GHE, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, 59, boulevard Pinel, 69500 Bron, France. Electronic address: cedric.barrey@chu-lyon.fr.
authors.forename: G
authors.initials: G
authors.lastname: Perrin
authors.affiliation: Service de Neurochirurgie C et Chirurgie du Rachis, Hôpital Pierre-Wertheimer, GHE, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: F
authors.initials: F
authors.lastname: Lucas
authors.affiliation: Service de Neurochirurgie C et Chirurgie du Rachis, Hôpital Pierre-Wertheimer, GHE, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: R
authors.initials: R
authors.lastname: Debarge
authors.affiliation: Service de Neurochirurgie C et Chirurgie du Rachis, Hôpital Pierre-Wertheimer, GHE, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, 59, boulevard Pinel, 69500 Bron, France; Laboratoire de Biomécanique, Art et Métiers Paristech, ESNAM, 151, boulevard de l'Hôpital, 75013 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Barrey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001863:Bone Screws; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult
keywords: C1-C2 fusion; C1-C2 instability; C1-C2 screws; Cervical fusion; Cervical spine arthrodesis; Harms