scholarly journals Effect of Direct Vertebral Rotation on the Uninstrumented Lumbar Curve in Thoracic Adolescent Idiopathic Scoliosis

2017 ◽  
Vol 11 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Sung-Soo Kim ◽  
Jung-Hoon Kim ◽  
Se-Il Suk
Keyword(s):  
Retrospective Study ◽  
Lumbar Spine ◽  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Group Versus ◽  
Vertebral Rotation ◽  
Lumbar Curve ◽  
Spontaneous Correction ◽  
Lowest Instrumented Vertebra ◽  
Coronal Correction

<sec><title>Study Design</title><p>Retrospective study.</p></sec><sec><title>Purpose</title><p>To determine the effect and direction of direct vertebral rotation (DVR) in the lowest instrumented vertebra (LIV) on the uninstrumented lumbar curve depending on the lumbar modifier used for the correction of thoracic adolescent idiopathic scoliosis.</p></sec><sec><title>Overview of Literature</title><p>DVR in the LIV should be implemented in a different direction to obtain better spontaneous lumbar correction depending on the preoperative lumbar spine modifier.</p></sec><sec><title>Methods</title><p>We retrospectively analyzed 160 patients with thoracic adolescent idiopathic scoliosis treated by pedicle screw instrumentation and rod derotation. Patients who had a distal fusion level between T11 and L1 were divided into two groups: the DVR group versus the No-DVR group. Each group was divided into subgroups depending on the lumbar modifier used: the DVR-A, B, and C groups versus the No-DVR-A, B, and C groups. The DVR-A group was subdivided into two subgroups depending on the direction of screw rotation in the LIV: the DVR-A-O group (opposite direction) and the DVR-A-S group (same direction).</p></sec><sec><title>Results</title><p>There were no significant differences in the preoperative curve characteristics between the two groups. The preoperative lumbar curve was corrected in 70% of the patients in the DVR group and in 56% in the No-DVR group. Spontaneous coronal correction of the lumbar curve was better in the DVR-A-S group than that in the No-DVR-A group. However, the DVR-A-O group had the higher incidence of adding-on deformity. The DVR-B and C groups showed better spontaneous correction of lumbar coronal magnitude, apical vertebral translation, and rotation and the LIV tilting.</p></sec><sec><title>Conclusions</title><p>In lumbar modifiers B and C, screws in the LIV have to be rotated opposite to the direction of the screw rotation of the main thoracic curve; however, in modifier A, the screws have to be rotated in the same direction.</p></sec>

scholarly journals Characteristics analysis of segmental and regional lumbar spontaneous compensation post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kai Chen ◽  
Xiao Zhai ◽  
Tianjunke Zhou ◽  
Yu Deng ◽  
Beichen Zhang ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Demographic Data ◽  
Wedge Angle ◽  
Lumbar Region ◽  
Lumbar Curve ◽  
Angle Variation ◽  
Spontaneous Correction

Abstract Objective To explore the characteristics of compensation of unfused lumbar region post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis. Background Preserving lumbar mobility in the compensation is significant in controlling pain and maintaining its functions. The spontaneous correction of the distal unfused lumbar curve after STF has been widely reported, but previous study has not concentrated on the characteristics of compensation of unfused lumbar region post thoracic fusion. Method A total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and we calculated their curve angles and compensations. Results The current study enrolled 41 females (80.4%) and 10 males (19.6%). Thirty-six patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1 ± 7.7°and 24.1 ± 9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84 ± 5.96°, 3.09 ± 4.54°, 2.30 ± 4.53°, − 0.12 ± 3.89° and − 1.36 ± 2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22 ± 10.39° and − 1.49 ± 5.14°, respectively. Conclusion When choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments’ compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

Spontaneous Lumbar Curve Coronal Correction After Selective Anterior or Posterior Thoracic Fusion in Adolescent Idiopathic Scoliosis

Spine ◽  
1999 ◽  
Vol 24 (16) ◽  
pp. 1663 ◽  
Author(s):  
Lawrence G. Lenke ◽  
Randal R. Betz ◽  
Keith H. Bridwell ◽  
Jurgen Harms ◽  
David H. Clements ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Lumbar Curve ◽  
Coronal Correction

scholarly journals Impact of lowest instrumented vertebra tilt and rotation on uninstrumented lumbar curve and L4 tilt in thoracic adolescent idiopathic scoliosis

2020 ◽  
Vol 33 (4) ◽  
pp. 471-479
Author(s):  
Akira Iwata ◽  
Hideki Sudo ◽  
Kuniyoshi Abumi ◽  
Manabu Ito ◽  
Katsuhisa Yamada ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Conflicts Of Interest ◽  
Linear Regression Analysis ◽  
Predictor Variables ◽  
Lumbar Curve ◽  
Absolute Value ◽  
Radiographic Measurements ◽  
Lowest Instrumented Vertebra ◽  
Posterior Correction

OBJECTIVEControversy exists regarding the effects of lowest instrumented vertebra (LIV) tilt and rotation on uninstrumented lumbar segments in adolescent idiopathic scoliosis (AIS) surgery. Because the intraoperative LIV tilt from the inferior endplate of the LIV to the superior sacral endplate is not stable after surgery, the authors measured the LIV angle of the instrumented thoracic spine as the LIV angle of the construct. This study aimed to evaluate the effects of the LIV angle of the construct and the effects of LIV rotation on the postoperative uninstrumented lumbar curve and L4 tilt in patients with thoracic AIS.METHODSA retrospective correlation and multivariate analysis of a prospectively collected, consecutive, nonrandomized series of patients at a single institution was undertaken. Eighty consecutive patients with Lenke type 1 or type 2 AIS treated with posterior correction and fusion were included. Preoperative and 2-year postoperative radiographic measurements were the outcome measures for this study. Outcome variables were postoperative uninstrumented lumbar segments (LIV tilt, LIV translation, uninstrumented lumbar curve, thoracolumbar/lumbar [TL/L] apical vertebral translation [AVT], and L4 tilt). The LIV angle of the construct was measured from the orthogonal line drawn from the upper instrumented vertebra to the LIV. Multiple stepwise linear regression analysis was conducted between outcome variables and patient demographics/radiographic measurements. There were no study-specific biases related to conflicts of interest.RESULTSPredictor variables for postoperative uninstrumented lumbar curve were the postoperative LIV angle of the construct, number of uninstrumented lumbar segments, and flexibility of TL/L curve. Specifically, a lower postoperative uninstrumented lumbar curve was predicted by a lower absolute value of the postoperative LIV angle of the construct (p < 0.0001). Predictor variables for postoperative L4 tilt were postoperative LIV rotation, preoperative L4 tilt, and preoperative uninstrumented lumbar curve. Specifically, a lower postoperative L4 tilt was predicted by a lower absolute value of postoperative LIV rotation (p < 0.0001).CONCLUSIONSThe LIV angle of the construct significantly affected the LIV tilt, uninstrumented lumbar curve, and TL/L AVT. LIV rotation significantly affected the LIV translation and L4 tilt.

scholarly journals Characteristics analysis of Segmental and Regional Lumbar Spontaneous Compensation Post Selective Thoracic Fusion in Lenke 1 and 2 Adolescent Idiopathic Scoliosis

2021 ◽  
Author(s):  
Kai Chen ◽  
Xiao Zhai ◽  
Tianjunke Zhou ◽  
Yu Deng ◽  
Shaofeng Chen ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Demographic Data ◽  
Wedge Angle ◽  
Lumbar Region ◽  
Lumbar Curve ◽  
Selective Thoracic Fusion ◽  
Spontaneous Correction

Abstract ObjectiveTo explore the characteristics of compensation of unfused lumbar region post selective thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis BackgroundPreserving lumbar mobility in the compensation is significant in controlling pain and maintaining its functions. The spontaneous correction of the distal unfused lumbar curve after STF has been widely reported, but previous study has not concentrated on the characteristics of compensation of unfused lumbar region post selective thoracic fusion.MethodA total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and calculated their curve angles and compensations.ResultsThe current study enrolled 41 females (80.4%) and 10 males (19.6%). 36 patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1±7.7°and 24.1±9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84±5.96°, 3.09±4.54°, 2.30±4.53°, -0.12±3.89° and -1.36±2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22±10.39° and -1.49±5.14°, respectively.ConclusionWhen choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments' compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

Upper instrumented vertebra to the right of the lowest instrumented vertebra as a predictor of an increase in the main thoracic curve after selective posterior fusion for the thoracolumbar/lumbar curve in Lenke type 5C adolescent idiopathic scoliosis: multicenter study on the relationship between fusion area and surgical outcome

2019 ◽  
Vol 31 (6) ◽  
pp. 857-864 ◽  
Author(s):  
Hiroki Oba ◽  
Jun Takahashi ◽  
Sho Kobayashi ◽  
Tetsuro Ohba ◽  
Shota Ikegami ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Posterior Fusion ◽  
Main Thoracic ◽  
Lowest Instrumented Vertebra ◽  
Line Tilt ◽  
The Right ◽  
Upper Instrumented Vertebra

OBJECTIVEUnfused main thoracic (MT) curvatures occasionally increase after selective thoracolumbar/lumbar (TL/L) fusion. This study sought to identify the predictors of an unacceptable increase in MT curve (UIMT) after selective posterior fusion (SPF) of the TL/L curve in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS).METHODSForty-eight consecutive patients (44 females and 4 males, mean age 15.7 ± 2.5 years, range 13–24 years) with Lenke type 5C AIS who underwent SPF of the TL/L curve were analyzed. The novel “Shinshu line” (S-line) was defined as a line connecting the centers of the concave-side pedicles of the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) on preoperative radiographs. The authors established an S-line tilt to the right as S-line positive (S-line+, i.e., the UIV being to the right of the LIV) and compared S-line+ and S-line− groups for thoracic apical vertebral translation (T-AVT) and MT Cobb angle preoperatively, early postoperatively, and at final follow-up. The predictors for T-AVT > 20 mm at final follow-up were evaluated as well. T-AVT > 20 mm was defined as a UIMT.RESULTSAmong the 48 consecutively treated patients, 26 were S-line+ and 22 were S-line−. At preoperative, early postoperative, and final follow-up a minimum of 2 years later, the mean T-AVT was 12.8 mm (range −9.3 to 32.8 mm), 19.6 mm (range −13.0 to 41.0 mm), and 22.8 mm (range −1.9 to 68.7 mm) in the S-line+ group, and 10.8 mm (range −5.1 to 27.3 mm), 16.2 mm (range −11.7 to 42.1 mm), and 11.0 mm (range −6.3 to 26.9 mm) in the S-line− group, respectively. T-AVT in S-line+ patients was significantly larger than that in S-line− patients at the final follow-up. Multivariate analysis revealed S-line+ (odds ratio [OR] 23.8, p = 0.003) and preoperative MT Cobb angle (OR 7.9, p = 0.001) to be predictors of a UIMT.CONCLUSIONSS-line+ was defined as the UIV being to the right of the LIV. T-AVT in the S-line+ group was significantly larger than in the S-line− group at the final follow-up. S-line+ status and larger preoperative MT Cobb angle were independent predictors of a UIMT after SPF for the TL/L curve in patients with Lenke type 5C AIS. Surgeons should consider changing the UIV and/or LIV in patients exhibiting S-line+ during preoperative planning to avoid a possible increase in MT curve and revision surgery.

Should L3 be selected as the lowest instrumented vertebra in patients with Lenke type 5C adolescent idiopathic scoliosis whose lowest end vertebra is L4?

2021 ◽  
pp. 1-10
Author(s):  
Tomohiro Banno ◽  
Yu Yamato ◽  
Hiroki Oba ◽  
Tetsuro Ohba ◽  
Tomohiko Hasegawa ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Curve Progression ◽  
Global Alignment ◽  
Fusion Surgery ◽  
Radiographic Outcomes ◽  
Lowest Instrumented Vertebra ◽  
Upper Instrumented Vertebra ◽  
Coronal Decompensation

OBJECTIVE L3 is most often selected as the lowest instrumented vertebra (LIV) to conserve mobile segments in fusion surgery; however, in cases with the lowest end vertebra (LEV) at L4, LIV selection as L3 could have a potential risk of correction loss and coronal decompensation. This study aimed to compare the clinical and radiographic outcomes depending on the LEV in adolescent idiopathic scoliosis (AIS) patients with Lenke type 5C curves. METHODS Data from 49 AIS patients with Lenke type 5C curves who underwent selective thoracolumbar/lumbar (TL/L) fusion to L3 as the LIV were retrospectively analyzed. The patients were classified according to their LEVs into L3 and L4 groups. In the L4 group, subanalysis was performed according to the upper instrumented vertebra (UIV) level toward the upper end vertebra (UEV and 1 level above the UEV [UEV+1] subgroups). Radiographic parameters and clinical outcomes were compared between these groups. RESULTS Among 49 patients, 32 and 17 were in the L3 and L4 groups, respectively. The L4 group showed a lower TL/L curve correction rate and a higher subjacent disc angle postoperatively than the L3 group. Although no intergroup difference was observed in coronal balance (CB), the L4 group showed a significantly higher main thoracic (MT) and TL/L curve progression during the postoperative follow-up period than the L3 group. In the L4 group, the UEV+1 subgroup showed a higher absolute value of CB at 2 years than the UEV subgroup. CONCLUSIONS In Lenke type 5C AIS patients with posterior selective TL/L fusion to L3 as the LIV, patients with their LEVs at L4 showed postoperative MT and TL/L curve progression; however, no significant differences were observed in global alignment and clinical outcome.

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