Cervical sagittal plane decompensation after surgery for adolescent idiopathic scoliosis: an effect imparted by postoperative thoracic hypokyphosis

Clinical article

Restricted access


Several studies have characterized the relationship among postoperative thoracic, lumbar, and pelvic alignment in the sagittal plane. However, little is known of the relationship between postoperative thoracic kyphosis and sagittal cervical alignment in patients with adolescent idiopathic scoliosis (AIS) treated with all pedicle screw constructs. The authors examined this relationship and associated factors.


A prospective database of pediatric patients with AIS undergoing spinal fusion between 2003 and 2005 was reviewed for those who received predominantly pedicle screw constructs for Lenke Type 1 or Type 2 curves. Parameters analyzed on pre- and postoperative radiographs were the fusion levels; cervical, thoracic, and lumbar sagittal balance; and C-2 and C-7 plumb lines.


Preoperatively, 6 (Group A) of the 22 patients included in the study had frank cervical kyphosis (mean angle 13.0°) with mean associated thoracic kyphosis of 27.2° (range 16°–37°). Postoperatively, cervical kyphosis (13.0°) remained in the patients in Group A along with mean thoracic kyphosis of 17.7° (range 4°–26°, p < 0.05). Preoperatively, the remaining 16 of 22 patients had neutral to lordotic cervical alignment (mean −13.8°) with thoracic kyphosis (mean 45°, range 30°–76°). Postoperatively, 8 (Group B) of these 16 patients demonstrated cervical sagittal decompensation (> 5° kyphosis), with 6 showing frank cervical kyphosis (10.5°, p < 0.05). In Group B, the mean postoperative thoracic kyphosis was 25.6° (range 7°–49°, p < 0.05). The other 8 patients (Group C) had mean postoperative thoracic kyphosis of 44.1° (range 32°–65°), and there was no cervical decompensation (p < 0.05).


The sagittal profile of the thoracic spine is related to that of the cervical spine. The surgical treatment of Lenke Type 1 and 2 curves by using all pedicle screw constructs has a significant hypokyphotic effect on thoracic sagittal plane alignment (19 [86%] of 22 patients). If postoperative thoracic kyphosis is excessively decreased (mean 25.6°, p < 0.05), the cervical spine may decompensate into significant kyphosis.

Abbreviations used in this paper: AIS = adolescent idiopathic scoliosis; UIV = upper instrumented vertebra.

Article Information

Address correspondence to: Steven W. Hwang, M.D., Department of Orthopedic Surgery, Shriner's Hospital for Children, 3551 North Broad Street, Philadelphia, Pennsylvania 19140. email: stevenhwang@hotmail.com.

Please include this information when citing this paper: published online July 29, 2011; DOI: 10.3171/2011.6.SPINE1012.

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Flow diagram illustrating the division of patients into subgroups based on study criteria.

  • View in gallery

    Preoperative lateral radiograph showing cervical lordosis (−1°) with thoracic kyphosis (45°).

  • View in gallery

    Postoperative lateral radiograph displaying decompensation of the cervical spine into kyphosis (15°) with thoracic hypokyphosis (11°).

  • View in gallery

    Scatter plot displaying preoperative association between cervical and thoracic alignment by patient groups (r = −0.62, p < 0.05; y = −0.533x + 36.696).

  • View in gallery

    Scatter plot displaying postoperative association between cervical and thoracic alignment by patient groups (r = −0.55, p < 0.05; y = −0.4281x + 30.046).



Asghar JSamdani AFPahys JMD'andrea LPGuille JTClements DH: Computed tomography evaluation of rotation correction in adolescent idiopathic scoliosis: a comparison of an all pedicle screw construct versus a hook-rod system. Spine (Phila Pa 1976) 34:8048072009


Clements DH IIIBetz RRNewton POMarks MCBastrom TP: The effect of implant density on the sagittal curve in scoliosis correction: correlation with number and type of fixation anchors. Presented at the 43rd Annual Scoliosis Research Society MeetingSalt Lake City, Utah2008. (Poster) (http://www.srs.org/professionals/meetings/am08/doc/e-poster_abstracts.pdf


Cruickshank JLKoike MDickson RA: Curve patterns in idiopathic scoliosis. A clinical and radiographic study. J Bone Joint Surg Br 71:2592631989


de Jonge TDubousset JFIllés T: Sagittal plane correction in idiopathic scoliosis. Spine (Phila Pa 1976) 27:7547602002


Edgar MAMehta MH: Long-term follow-up of fused and unfused idiopathic scoliosis. J Bone Joint Surg Br 70:7127161988


Glassman SDBerven SBridwell KHorton WDimar JR: Correlation of radiographic parameters and clinical symptoms in adult scoliosis. Spine (Phila Pa 1976) 30:6826882005


Grob DFrauenfelder HMannion AF: The association between cervical spine curvature and neck pain. Eur Spine J 16:6696782007


Hilibrand ASTannenbaum DAGraziano GPLoder RTHensinger RN: The sagittal alignment of the cervical spine in adolescent idiopathic scoliosis. J Pediatr Orthop 15:627 6321995


Kim YJLenke LGCho SKBridwell KHSides BBlanke K: Comparative analysis of pedicle screw versus hook instrumentation in posterior spinal fusion of adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 29:204020482004


Koski TRNasr FO'Shaughnessy BAOndra SL: Analysis of global sagittal balance using cranial center of mass as a reference point. Presented at the 43rd Annual Scoliosis Research Society MeetingSalt Lake City, Utah2008. (Poster) (http://www.srs.org/professionals/meetings/am08/doc/e-poster_abstracts.pdf


Lowenstein JEMatsumoto HVitale MGWeidenbaum MGomez JALee FY: Coronal and sagittal plane correction in adolescent idiopathic scoliosis: a comparison between all pedicle screw versus hybrid thoracic hook lumbar screw constructs. Spine (Phila Pa 1976) 32:4484522007


Mac-Thiong JMLabelle HCharlebois MHuot MPde Guise JA: Sagittal plane analysis of the spine and pelvis in adolescent idiopathic scoliosis according to the coronal curve type. Spine (Phila Pa 1976) 28:140414092003


McCance SEDenis FLonstein JEWinter RB: Coronal and sagittal balance in surgically treated adolescent idiopathic scoliosis with the King II curve pattern. A review of 67 consecutive cases having selective thoracic arthrodesis. Spine (Phila Pa 1976) 23:206320731998


Moskowitz AMoe JHWinter RBBinner H: Long-term follow-up of scoliosis fusion. J Bone Joint Surg Am 62:364 3761980


Ofiram EGarvey TASchwender JDWroblewski JMWinter RB: Cervical degenerative changes in idiopathic scoliosis patients who underwent long fusion to the sacrum as adults: incidence, severity, and evolution. J Orthop Traumatol 10:27302009


Poncet PDansereau JLabelle H: Geometric torsion in idiopathic scoliosis: three-dimensional analysis and proposal for a new classification. Spine (Phila Pa 1976) 26:223522432001


Schwab FLafage VBoyce RSkalli WFarcy JP: Gravity line analysis in adult volunteers: age-related correlation with spinal parameters, pelvic parameters, and foot position. Spine (Phila Pa 1976) 31:E959E9672006


Sucato DJAgrawal SO'Brien MFLowe TGRichards SBLenke L: Restoration of thoracic kyphosis after operative treatment of adolescent idiopathic scoliosis: a multicenter comparison of three surgical approaches. Spine (Phila Pa 1976) 33:263026362008


Stokes IA: Three-dimensional terminology of spinal deformity. A report presented to the Scoliosis Research Society by the Scoliosis Research Society Working Group on 3-D terminology of spinal deformity. Spine (Phila Pa 1976) 19:2362481994


Upasani VVTis JBastrom TPawelek JMarks MLonner B: Analysis of sagittal alignment in thoracic and thoracolumbar curves in adolescent idiopathic scoliosis: how do these two curve types differ?. Spine (Phila Pa 1976) 32:135513592007


Winter RBLovell WWMoe JH: Excessive thoracic lordosis and loss of pulmonary function in patients with idiopathic scoliosis. J Bone Joint Surg Am 57:9729771975




All Time Past Year Past 30 Days
Abstract Views 7 7 7
Full Text Views 20 20 12
PDF Downloads 72 72 49
EPUB Downloads 0 0 0


Google Scholar