Clinical Study| Volume 23, ISSUE 6, P841-850, June 2023

Download started.


Establishing a relationship using CT between facet distraction and clinical outcomes after ACDF

Published:February 14, 2023DOI:


      • The relationship between the clinical outcomes and facet distraction after anterior cervical discectomy and fusion (ACDF) remains unclear.
      • Δ Facet distraction measured using computed tomography strongly correlated with neck pain, and over-distraction contributed to adverse long-term outcomes, including neck and arm pain after ACDF.
      • An Δ over-distraction of ≥1.8 mm may cause radiculopathy of adjacent segments along with facet-mediated axial pain.
      • Cage height should be carefully determined to avoid over-distraction during ACDF.



      Anterior cervical discectomy and fusion (ACDF), the gold standard treatment for radiculopathy and myelopathy, has the potential risk of inducing facet-mediated pain through over-distraction. However, the relationship between the clinical outcomes and facet distraction after ACDF remains unclear.


      To measure facet distraction using computed tomography (CT) and compare the results with the clinical outcomes after ACDF.


      Retrospective cohort study.


      A consecutive series of patients (n = 144) who underwent a single-level ACDF were included.


      Interfacet distance on preoperative and postoperative lateral cervical radiographs and CT. Visual analog scale for neck pain (VASn), and arm pain (VASa), neck disability index (NDI), the Short Form 36-item health survey (SF-36) were used for clinical outcomes.


      Each patient underwent plain radiography of the lateral cervical spine preoperatively, immediately and two years postsurgery. CT was performed preoperatively, and at 3 days and 1-year postsurgery. The inter-facet distance was measured at each time point, and changes in values from the preoperative distance were noted and used for study. Patient-reported outcome measures were obtained preoperatively and at 2-year follow-up. Receiver operating characteristic (ROC) curves were generated to derive the critical facet distraction point.


      The 3 weeks postoperative VASn score was the most severe and showed a tendency to decrease during the follow-up period. There was a significant positive correlation between the change value of facet distraction measured using CT and 3 weeks postoperative VASn score. ROC curve analysis showed that the cut-off value of Δ facet distraction was 1.8 mm. The over-distraction group (Δ facet distraction ≥1.8 mm, n = 75) showed significantly worse clinical outcomes than the control group (Δ facet distraction <1.8 mm, n = 69), including neck and arm pain VAS scores at all time points until the final 2-year follow-up.


      The change value of facet distraction measured using CT rather than plain radiography correlated better with neck pain, and over-distraction contributed to adverse long-term outcomes, including neck and arm pain after ACDF. Additionally, an over-distraction of ≥1.8 mm may cause radiculopathy of adjacent segments along with facet-mediated axial pain; therefore, cage height should be carefully determined to avoid over-distraction during ACDF.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The Spine Journal
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Lad SP
        • Patil CG
        • Berta S
        • Santarelli JG
        • Ho C
        • Boakye M.
        National trends in spinal fusion for cervical spondylotic myelopathy.
        Surg Neurol. 2009; 71 (discussion 9): 66-69
        • Kang K-C
        • Lee HS
        • Lee J-H
        Cervical radiculopathy focus on characteristics and differential diagnosis.
        Asian Spine J. 2020; 14: 921-930
        • Choi SH
        • Kang C-N.
        Degenerative cervical myelopathy: pathophysiology and current treatment strategies.
        Asian Spine J. 2020; 14: 710-720
        • Bohlman HH
        • Emery SE
        • Goodfellow DB
        • Jones PK.
        Robinson anterior cervical discectomy and arthrodesis for cervical radiculopathy. Long-term follow-up of one hundred and twenty-two patients.
        J Bone Joint Surg Am. 1993; 75: 1298-1307
        • Bayley JC
        • Yoo JU
        • Kruger DM
        • Schlegel J.
        The role of distraction in improving the space available for the cord in cervical spondylosis.
        Spine (Phila Pa 1976). 1995; 20: 771-775
      1. Karamian BA, Levy HA, Canseco JA, Goyal DKC, Divi SN, Lee JK, et al. Does facet distraction affect patient outcomes after ACDF? [e-pub ahead of print]. Global Spine J 2021;21925682211004244. doi: 10.1177/21925682211004244.

        • Kirzner N
        • Etherington G
        • Ton L
        • Chan P
        • Paul E
        • Liew S
        • et al.
        Relationship between facet joint distraction during anterior cervical discectomy and fusion for trauma and functional outcome.
        Bone Joint J. 2018; 100-b: 1201-1207
        • Chang H
        • Baek DH
        • Choi BW.
        The relationship between increased intervertebral disc height and development of postoperative axial neck pain after anterior cervical fusion.
        J Korean Neurosurg Soc. 2014; 55: 343-347
        • Lin Z
        • Wang Z
        • Chen G
        • Lin T
        • Liu W
        Is facet joint distraction associated with functional outcome in patients with cervical spondylotic radiculopathy treated with single-segment anterior cervical discectomy and fusion?.
        World Neurosurg. 2020; 140: e53-e60
        • Lawless MH
        • Yoon EJ
        • Jasinski JM
        • Gabrail J
        • Jordan N
        • Kado K
        • et al.
        Impact of interspace distraction on fusion and clinical outcomes in anterior cervical discectomy and fusion: a longitudinal cohort study.
        Asian Spine J. 2022; 16: 369-374
        • Bono CM
        • Schoenfeld A
        • Rampersaud R
        • Levi A
        • Grauer J
        • Arnold P
        • et al.
        Reproducibility of radiographic measurements for subaxial cervical spine trauma.
        Spine. 2011; 36: 1374-1379
        • Wellborn CC
        • Sturm PF
        • Hatch RS
        • Bomze SR
        • Jablonski K.
        Intraobserver reproducibility and interobserver reliability of cervical spine measurements.
        J Pediatr Orthop. 2000; 20: 66
        • Landis JR
        • Koch GG.
        The measurement of observer agreement for categorical data.
        Biometrics. 1977; 33: 159-174
        • Rovai AP
        • Baker JD
        • Ponton MK
        Social science research design and statistics: a practitioner’s guide to research methods and IBM SPSS.
        Watertree Press LLC, Chesapeake, VA, 233282013
        • Boonstra AM
        • Schiphorst Preuper HR
        • Balk GA
        • Stewart RE.
        Cut-off points for mild, moderate, and severe pain on the visual analogue scale for pain in patients with chronic musculoskeletal pain.
        Pain. 2014; 155: 2545-2550
        • Fejer R
        • Jordan A
        • Hartvigsen J.
        Categorising the severity of neck pain: establishment of cut-points for use in clinical and epidemiological research.
        Pain. 2005; 119: 176-182
        • Truumees E
        • Demetropoulos CK
        • Yang KH
        • Herkowitz HN.
        Effects of disc height and distractive forces on graft compression in an anterior cervical discectomy model.
        Spine (Phila Pa 1976). 2002; 27: 2441-2445
        • Cavanaugh JM
        • Lu Y
        • Chen C
        • Kallakuri S
        Pain generation in lumbar and cervical facet joints.
        J Bone Joint Surg Am. 2006; 88: 63-67
        • Liu J
        • Ebraheim NA
        • Haman SP
        • Sanford CGJ
        • Sairyo K
        • Faizan A
        • et al.
        How the increase of the cervical disc space height affects the facet joint: an anatomy study.
        Spine. 2006; 31: E350-E3E4
        • Olsewski JM
        • Garvey TA
        • Schendel MJ.
        Biomechanical analysis of facet and graft loading in a Smith-Robinson type cervical spine model.
        Spine (Phila Pa 1976). 1994; 19: 2540-2544
        • Muller MP
        • Tomlinson G
        • Marrie TJ
        • Tang P
        • McGeer A
        • Low DE
        • et al.
        Can routine laboratory tests discriminate between severe acute respiratory syndrome and other causes of community-acquired pneumonia?.
        Clin Infect Dis. 2005; 40: 1079-1086
        • Xiong W
        • Zhou J
        • Sun C
        • Chen Z
        • Guo X
        • Huo X
        • et al.
        0.5- to 1-fold intervertebral distraction is a protective factor for adjacent segment degeneration in single-level anterior cervical discectomy and fusion.
        Spine. 2020; 45: 96-102
        • Li J
        • Li Y
        • Kong F
        • Zhang D
        • Zhang Y
        • Shen Y.
        Adjacent segment degeneration after single-level anterior cervical decompression and fusion: disc space distraction and its impact on clinical outcomes.
        J Clin Neurosci. 2015; 22: 566-569
        • Rao RD
        • Wang M
        • McGrady LM
        • Perlewitz TJ
        • David KS.
        Does anterior plating of the cervical spine predispose to adjacent segment changes?.
        Spine. 2005; 30: 2788-2792
        • Park DK
        • Lin EL
        • Phillips FM.
        Index and adjacent level kinematics after cervical disc replacement and anterior fusion: in vivo quantitative radiographic analysis.
        Spine. 2011; 36: 721-730
        • Hilibrand AS
        • Carlson GD
        • Palumbo MA
        • Jones PK
        • Bohlman HH.
        Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis.
        JBJS. 1999; 81: 519-528