Association of Postoperative Shoulder Balance With Adding-on in Lenke Type II Adolescent Idiopathic Scoliosis

OBJECTIVEThe incidence of postoperative shoulder imbalance following posterior spinal fusion (PSF) is still high in Lenke 1 curves despite following current treatment recommendations for upper instrumented vertebra (UIV) selection. The objective of this retrospective study was to identify differences in preoperative shoulder balance and to report the surgical outcome of two subtypes of Lenke 1 curves (flexible vs stiff) in patients with adolescent idiopathic scoliosis (AIS).METHODSThe authors grouped patients’ curves as Lenke 1–ve (flexible) when their preoperative proximal thoracic side bending (PTSB) Cobb angle was < 15° and as Lenke 1+ve (stiff) when the PTSB Cobb angle was 15°–24.9°. The authors hypothesized that these two subtypes had distinct preoperative and postoperative shoulder and neck balance following PSF using pedicle screw constructs.RESULTSFifty patients had Lenke 1 (flexible) curves and 61 had Lenke 1 (stiff) curves. The mean preoperative T1 tilt for patients with Lenke 1 (flexible) was −4.9° ± 5.3°, and for those with Lenke 1 (stiff) curves it was −1.0° ± 5.3° (p < 0.001). Mean cervical axis (CA) was −0.1° ± 3.2° for Lenke 1 (flexible) curves and 2.3° ± 3.5° for Lenke 1 (stiff) curves (p < 0.001). Preoperative radiographic shoulder height (RSH) and clavicle angle (Cla-A) were similar between the two curve subtypes. Following surgery, there were significant differences between the subtypes in terms of T1 tilt (p < 0.001), RSH (p = 0.014), and Cla-A (p = 0.031). Interestingly, 41.0% of patients with a Lenke 1 (stiff) curve had +ve T1 tilt compared to 2.0% in Lenke 1 (flexible) group. Moreover, 26.2% of patients with the Lenke 1 (stiff) curve had +ve RSH compared to 12.0% of those with Lenke 1 (flexible) curves. And, 24.6% of patients with Lenke 1 (stiff) had +ve Cla-A compared to 10.0% of those with Lenke 1 (flexible) curves.CONCLUSIONSLenke 1 (flexible) and Lenke 1 (stiff) curves had distinct preoperative T1 tilt and CA measurements. Following PSF, the authors noted +ve T1 tilt in 41% of patients with Lenke 1 (stiff) curves versus 2.0% in those with Lenke 1 (flexible) curves. The authors also noted a significant difference in postoperative RSH and Cla-A measurements.

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Predictors for Postoperative Shoulder Balance in Lenke 1 Adolescent Idiopathic Scoliosis: A Prospective Cohort Study

Spine Deformity ◽

10.1016/j.jspd.2016.09.046 ◽

2017 ◽

Vol 5 (1) ◽

pp. 66-71 ◽

Cited By ~ 6

Author(s):

Alberto O. Gotfryd ◽

Maria Fernanda Silber Caffaro ◽

Robert Meves ◽

Osmar Avanzi

Keyword(s):

Cohort Study ◽

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Shoulder Balance ◽

Postoperative Shoulder

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The Amount of Relative Curve Correction Is More Important Than Upper Instrumented Vertebra Selection for Ensuring Postoperative Shoulder Balance in Lenke Type 1 and Type 2 Adolescent Idiopathic Scoliosis

Spine ◽

10.1097/brs.0000000000003088 ◽

2019 ◽

Vol 44 (17) ◽

pp. E1031-E1037 ◽

Cited By ~ 6

Author(s):

John Alex Sielatycki ◽

Meghan Cerpa ◽

Eduardo C. Beauchamp ◽

Takayoshi Shimizu ◽

Chao Wei ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Curve Correction ◽

Shoulder Balance ◽

Selection For ◽

Upper Instrumented Vertebra ◽

Postoperative Shoulder ◽

Relative Curve

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Preoperative “Cervical Axis” Deviation Increases the Risk of Distal Adding-On Following Surgery in Lenke 1 and 2 Adolescent Idiopathic Scoliosis Patients

Global Spine Journal ◽

10.1177/2192568221998642 ◽

2021 ◽

pp. 219256822199864

Author(s):

Chris Yin Wei Chan ◽

Pei Ying Ch’ng ◽

Sin Ying Lee ◽

Weng Hong Chung ◽

Chee Kidd Chiu ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Predictive Factors ◽

Multivariate Logistic Regression Analysis ◽

Shoulder Balance ◽

Lowest Instrumented Vertebra ◽

The Relationship ◽

Postoperative Shoulder

Study Design: Retrospective. Purpose: To evaluate the relationship between shoulder/ neck imbalance with distal adding-on phenomenon and to identify other risk factors in Lenke 1 and 2 (non-AR curves) adolescent idiopathic scoliosis (AIS) patients. Methods: 100 Lenke 1 and 2 AIS patients with lowest instrumented vertebra (LIV) cephalad to or at L1 were recruited. Medial shoulder/ neck balance was represented by T1-tilt and cervical axis (CA). Lateral shoulder balance was represented by clavicle angle (Cla-A) and radiographic shoulder height (RSH). Distal adding-on phenomenon was diagnosed when there was disc wedging below LIV of >5o at final follow-up. Predictive factors and odds ratio were derived using univariate and multivariate logistic regression analysis. Results: Mean age of this cohort was 15.9 ± 4.4 years. Mean follow-up duration was 30.9 ± 9.6 months. Distal adding-on phenomenon occurred in 19 patients (19.0%). Only Risser grade, preoperative CA and final follow-up lumbar Cobb angle were the independent factors. A positive preoperative CA deviation increased the odds of distal adding-on by 5.4 times (95% CI 1.34-21.51, P = 0.018). The mean immediate postoperative T1-tilt, CA, RSH and Cla-A were comparable between the group with distal adding-on and the group without. Conclusion: Distal adding-on phenomenon occurred in 19.0% of patients. Preoperative “Cervical Axis” was an important factor and it increased the risk of distal adding-on by 5.4 times. Other significant predictive factors were Risser grade and lumbar Cobb angle at final follow-up. Immediate postoperative shoulder or neck imbalance was not a significant factor for postoperative distal adding-on phenomenon.

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