Preoperative pelvic obliquity: possible relation to postoperative coronal decompensation in thoracolumbar/lumbar adolescent idiopathic scoliosis

2021 ◽  
pp. 1-10
Author(s):  
Tomohiro Banno ◽  
Yu Yamato ◽  
Hiroki Oba ◽  
Tetsuro Ohba ◽  
Tomohiko Hasegawa ◽  
...  

OBJECTIVE Pelvic obliquity is frequently observed in patients with adolescent idiopathic scoliosis with thoracolumbar/lumbar (TL/L) curve. This study aimed to assess pelvic obliquity changes and their effects on clinical outcomes of posterior fusion surgery. METHODS Data in 80 patients (69 with type 5C and 11 with type 6C adolescent idiopathic scoliosis) who underwent posterior fusion surgery were retrospectively analyzed. Pelvic obliquity was defined as an absolute pelvic obliquity angle (POA) value of ≥ 3°. The patients were divided into groups according to preoperative pelvic obliquity. Moreover, patients with preoperative pelvic obliquity were divided based on POA change from preoperative values versus 2 years postoperatively. Patients were divided based on the presence of selective or nonselective TL/L fusion. Radiographic parameters and clinical outcomes were compared between these groups. RESULTS Among 80 patients, 41 (51%) showed preoperative pelvic obliquity, and its direction was upward to the right for all cases. Coronal decompensation 2 years postoperatively was significantly elevated in patients with preoperative pelvic obliquity (p < 0.05). Thirty-two patients (40%) displayed pelvic obliquity 2 years postoperatively. Among 41 patients with preoperative pelvic obliquity, 22 patients (54%) were in the group with a decrease in POA, and 19 were in the group with no decrease. The group with no decrease in POA showed significant TL/L curve progression throughout the postoperative follow-up period. The patients with nonselective fusion showed a significantly lower incidence of pelvic obliquity at 2 years postoperatively. CONCLUSIONS Postoperative coronal decompensation more frequently occurred in patients with preoperative pelvic obliquity than in those without pelvic obliquity preoperatively. In addition, postoperative pelvic obliquity changes may be related to residual lumbar curve behavior.

2019 ◽  
Vol 31 (6) ◽  
pp. 857-864 ◽  
Author(s):  
Hiroki Oba ◽  
Jun Takahashi ◽  
Sho Kobayashi ◽  
Tetsuro Ohba ◽  
Shota Ikegami ◽  
...  

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.


2021 ◽  
pp. 1-10
Author(s):  
Tomohiro Banno ◽  
Yu Yamato ◽  
Hiroki Oba ◽  
Tetsuro Ohba ◽  
Tomohiko Hasegawa ◽  
...  

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.


2018 ◽  
Vol 100-B (10) ◽  
pp. 1372-1376 ◽  
Author(s):  
H. Bao ◽  
Z. Liu ◽  
M. Bao ◽  
Z. Zhu ◽  
P. Yan ◽  
...  

Aims The aim of this study was to investigate the impact of maturity status at the time of surgery on final spinal height in patients with an adolescent idiopathic scoliosis (AIS) using the spine-pelvic index (SPI). The SPI is a self-control ratio that is independent of age and maturity status. Patients and Methods The study recruited 152 female patients with a Lenke 1 AIS. The additional inclusion criteria were a thoracic Cobb angle between 45° and 70°, Risser 0 to 1 or 3 to 4 at the time of surgery, and follow-up until 18 years of age or Risser stage 5. The patients were stratified into four groups: Risser 0 to 1 and selective fusion surgery (Group 1), Risser 0 to 1 and non-selective fusion (Group 2), Risser 3 to 4 and selective fusion surgery (Group 3), and Risser 3 to 4 and non-selective fusion (Group 4). The height of spine at follow-up (HOSf) and height of pelvis at follow-up (HOPf) were measured and the predicted HOS (pHOS) was calculated as 2.22 (SPI) × HOPf. One-way analysis of variance (ANOVA) was performed for statistical analysis. Results Of the 152 patients, there were 32 patients in Group 1, 27 patients in Group 2, 48 patients in Group 3, and 45 patients in Group 4. Significantly greater HOSf was observed in Group 3 compared with Group 1 (p = 0.03) and in Group 4 compared with Group 2 (p = 0.02), with similar HOPf (p = 0.75 and p = 0.83, respectively), suggesting that patients who undergo surgery at Risser grade of 0 to 1 have a shorter spinal height at follow-up than those who have surgery at Risser 4 to 5. HOSf was similar to pHOS in both Group 1 and Group 2 (p = 0.62 and p = 0.45, respectively), indicating that undergoing surgery at Risser 0 to 1 does not necessarily affect final spinal height. Conclusion This study shows that fusion surgery at Risser 0 may result in growth restriction unlike fusion surgery at Risser 3 to 4. Despite such growth restriction, AIS patients could reach their predicted or ‘normal’ spinal height after surgery regardless of baseline maturity status due to the longer baseline spinal length in AIS patients and the remaining growth potential at the non-fusion levels. Cite this article: Bone Joint J 2018;100-B:1372–6.


2020 ◽  
pp. 219256822096556
Author(s):  
Kai Chen ◽  
Yu Chen ◽  
Jie Shao ◽  
Junke Zhoutian ◽  
Fei Wang ◽  
...  

Study Design: Retrospective study. Objective: The aim of this study was to assess long-term radiographic and clinical outcomes in Lenke 5C adolescent idiopathic scoliosis (AIS) patients after posterior selective fusion. Methods: Lenke 5C AIS patients who underwent posterior selective thoracolumbar/lumbar (TL/L) fusion in our hospital from January 2007 to January 2010 were recruited. Radiographic parameters were measured preoperatively and at the 3-month, 1-year, 2-year, 5-year, and 10-year follow-ups. The SRS-22 (Scoliosis Research Society) questionnaire was used to assess the clinical outcomes. Results: We included 37 patients who underwent posterior selective TL/L fusion surgery in our study, and the mean follow-up time was 11.26 ± 0.85 years. The average preoperative Cobb angles of the thoracic and TL/L curves were 24.0 ± 9.0° and 45.4 ± 6.3°, respectively, which were corrected to 12.2° and 12.4° at the 3-month follow-up postoperatively, with correction losses of 2.2° and 1.5° at the 10-year follow-up. In the sagittal plane, the degree of thoracic kyphosis (TK) gradually increased over the follow-up period. The proximal junctional angle (PJA) also gradually increased from 6.7 ± 4.6 to 13.7 ± 5.6 during the follow-up period. For the clinical outcomes, correction surgery improved the SRS-22 scores in each domain, especially in the self-image domain. Conclusions: Posterior selective TL/L fusion can effectively correct spinal deformities, leading to stable outcomes for 10 years postoperatively. During the follow-up period, the degree of TK presented an increasing trend that remained almost constant after the 1-year follow-up. Moreover, the variation in the PJA was highly significant in the postoperative period, and it showed an increasing trend until the 2-year follow-up.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kai Chen ◽  
Xiao Zhai ◽  
Tianjunke Zhou ◽  
Yu Deng ◽  
Beichen Zhang ◽  
...  

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.


Author(s):  
Michael Faloon ◽  
Roger F. Widmann ◽  
John S. Blanco ◽  
Matthew E. Cunningham ◽  
Bernard A. Rawlins ◽  
...  

2018 ◽  
Vol 6 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Masayuki Ohashi ◽  
Toru Hirano ◽  
Kei Watanabe ◽  
Keiichi Katsumi ◽  
Hirokazu Shoji ◽  
...  

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