Postoperative proximal junctional kyphosis in Lenke 5C adolescent idiopathic scoliosis following posterior surgery: extending fusion versus thoracolumbar/lumbar fusion

2020 ◽  
Author(s):  
Bowen Hu ◽  
Linnan Wang ◽  
Xin He ◽  
Yueming Song ◽  
Xi Yang ◽  
...  

Abstract Background: Proximal junctional kyphosis is a common complication after posterior fusion in adolescent idiopathic scoliosis patients, and was correlated with postoperative change of thoracic kyphosis. However, no previous literature has evaluated the correlation of PJK with thoracervical parameters in the AIS patients. Methods: Data from 61 patients who underwent posterior fusion for Lenke 5C AIS and had 2 years of follow-up were retrospectively reviewed. Patients were fused higher than two levels above the upper-end-vertebra in the extended fusion group (n=32), whereas they were fused below or at UEV+2 in the TL/L fusion group (n=29). Results: During an average follow-up of 32.5 months, 14/61 patients had PJK. The extended fusion group had a greater incidence of PJK than the TL/L fusion group did (11/32 vs. 3/29,P = 0.03) and a significant more decrease of TK than the TL/L group(p<0.01). Patients with PJK had a significantly larger Thoracic inlet angle(TIA) than those without PJK (P <0.01). Multivariate analysis revealed a greater preoperative TIA to be a positive predictor for PJK (p = 0.015). TIA >72° with extended fusion was a risk factor for PJK at final follow-up. The SRS-22 score did not significantly differ between the extended fusion and TL/L fusion groups. Conclusions: TIA could be a predictor of PJK. In Lenke 5C AIS patients, those with TIA >72° were more likely to develop PJK. And extended fusion in patients with Lenke 5C adolescent idiopathic scoliosis may be at an increased risk of proximal junctional kyphosis.

2021 ◽  
Vol 10 (22) ◽  
pp. 5351
Author(s):  
Hong Jin Kim ◽  
Jae Hyuk Yang ◽  
Dong-Gune Chang ◽  
Se-Il Suk ◽  
Seung Woo Suh ◽  
...  

Several studies have reported incidence and risk factors for the development of proximal junctional kyphosis (PJK) in patients with adolescent idiopathic scoliosis (AIS). However, there is little information regarding long-term follow-up after pedicle screw instrumentation (PSI) with rod derotation (RD) and direct vertebral rotation (DVR). Sixty-nine AIS patients who underwent deformity correction using PSI with RD and DVR were retrospectively analyzed in two groups according to the occurrence of PJK, with a minimum five-year follow-up, including a non-PJK group (n = 62) and PJK group (n = 7). Radiological parameters were evaluated at preoperative, postoperative, and last follow-up. Incidence for PJK was 10.1% (7/69 patients), with a mean 9.4-year follow-up period. The thoracolumbar/lumbar curve (TL/L curve) was proportionally higher in the PJK group. The proximal compensatory curve was significantly lower in the PJK group than in the non-PJK group preoperatively (p = 0.027), postoperatively (p = 0.001), and at last follow-up (p = 0.041). The development of PJK was associated with the TL/L curve pattern, lower preoperative proximal compensatory curve, and over-correction of the proximal curve for PSI with RD and DVR. Therefore, careful evaluation of compensatory curves as well as of the main curve is important to prevent the development of PJK in the treatment of AIS.


2019 ◽  
Author(s):  
Jie Wang ◽  
Ningning Yang ◽  
Ming Luo ◽  
Ning Li ◽  
Yonggang Fan ◽  
...  

Abstract Background: There are several risk factors for proximal junctional kyphosis (PJK) in adolescent idiopathic scoliosis (AIS) surgery. Decreased rod contouring angle (RCA) has been proposed as a risk factor for PJK, but the role of difference between proximal junctional angle (PJA) and RCA (PJA-RCA) has not been fully investigated. The aim of this study was to assess the role of PJA-RCA for the development of postoperative PJK in AIS. Methods: We performed a retrospective analysis of 96 AIS patients who underwent posterior segmental spinal instrumentation and fusion between the years 2012 and 2018 (minimum 1.5-year and average 2-year follow-up) at a single institution. Each patient was measured on preoperative, postoperative and final follow-up long-cassette standing radiographs. The PJA-RCA was regarded as a new definition that reflects the match degree between proximal rod contouring and vertebra curvature, and radiographic parameters were compared between PJK and non-PJK group. Results : Among the 96 patients with a mean age of 14.00 years (± 0.82), the overall incidence of PJK was 22%. PJK group showed a significantly greater preoperative SVA (P = 0.032) and larger correction of SVA (P = 0.007) than non-PJK group. At the last follow-up, PJK patients had significantly greater LL (P = 0.046). Patients in the PJK group had significantly greater preoperative PJA-RCA than the non-PJK group (4.07±3.30 vs. 1.42±4.28, P = 0.024). However, RCA was not significantly different between two groups (3.88 ± 4.34 vs. 2.86 ± 3.36, P = 0.405). In addition, Pearson correlation coefficient showed a significant correlation between the change of SVA and the last follow-up PJA (r = -0.208, P = 0.042). Preoperative PJA-RCA and postoperative PJA-RCA demonstrated similar results which showed a strong correlation with the last follow-up PJA (r = 0.528 and r = 0.532 respectively, P < 0.000). Conclusions: As a new reflex of improper rod contouring, large PJA-RCA is a risk factor for PJK in AIS, and PJK might be a compensation mechanism rather than complication when spine is shifted and overcorrected. Keywords: adolescent idiopathic scoliosis, proximal junctional kyphosis, proximal junctional angle, rod contouring angle.


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 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.


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