The Sagittal Thoracic Modifier Component of the Lenke Classification System in Moderate and Severe Adolescent Idiopathic Scoliosis

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.

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A Decision Tree Can Increase Accuracy When Assessing Curve Types According to Lenke Classification of Adolescent Idiopathic Scoliosis

Spine ◽

10.1097/brs.0b013e3181bf280e ◽

2010 ◽

Vol 35 (10) ◽

pp. 1054-1059 ◽

Cited By ~ 6

Author(s):

Philippe Phan ◽

Neila Mezghani ◽

Marie-Lyne Nault ◽

Carl-Éric Aubin ◽

Stefan Parent ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Decision Tree ◽

Idiopathic Scoliosis ◽

Lenke Classification

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What happens to the unfused upper thoracic curve after posterior spinal fusion for adolescent idiopathic scoliosis?

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.10.peds20671 ◽

2021 ◽

pp. 1-7

Author(s):

M. Omar Iqbal ◽

Amer F. Samdani ◽

Joshua M. Pahys ◽

Peter O. Newton ◽

Suken A. Shah ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Univariate Analysis ◽

Posterior Spinal Fusion ◽

Research Society ◽

Curve Correction ◽

Scoliosis Research Society ◽

Lenke Classification ◽

Upper Instrumented Vertebra ◽

Upper Thoracic

OBJECTIVE Spontaneous lumbar curve correction after selective thoracic fusion in surgery for adolescent idiopathic scoliosis (AIS) is well described. However, only a few articles have described the course of the uninstrumented upper thoracic (UT) curve after fusion, and the majority involve a hybrid construct. In this study, the authors sought to determine the outcomes and associated factors of uninstrumented UT curves in patients with AIS. METHODS The authors retrospectively reviewed a prospectively collected multicenter AIS registry for all consecutive patients with Lenke type 1–4 curves with a 2-year minimum follow-up. UT curves were considered uninstrumented if the upper instrumented vertebra (UIV) did not extend above 1 level from the lower end vertebra of the UT curve. The authors defined progression as > 5°, and divided patients into two cohorts: those with improvement in the UT curve (IMP) and those without improvement in the UT curve (NO IMP). Radiographic, demographic, and Scoliosis Research Society (SRS)–22 survey outcome measures were compared using univariate analysis, and significant factors were compared using a multivariate regression model. RESULTS The study included 450 patients (370 females and 80 males). The UT curve self-corrected in 86% of patients (n = 385), there was no change in 14% (n = 65), and no patients worsened. Preoperatively, patients were similar with respect to Lenke classification (p = 0.44), age (p = 0.31), sex (p = 0.85), and Risser score (p = 0.14). The UT curves in the IMP group self-corrected from 24.7° ± 6.5° to 12.6° ± 5.9°, whereas in the NO IMP group UT curves remained the same, from 20.3° ± 5.8° to 18.5° ± 5.7°. In a multivariate analysis, preoperative main thoracic (MT) curve size (p = 0.004) and MT curve correction (p = 0.001) remained significant predictors of UT curve improvement. Greater correction of the MT curve and larger initial MT curve size were associated with greater likelihood of UT curve improvement. CONCLUSIONS Spontaneous UT curve correction occurred in the majority (86%) of unfused UT curves after MT curve correction in Lenke 1–4 curve types. The magnitude of preoperative MT curve size and postoperative MT curve correction were independent predictors of spontaneous UT curve correction.

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Choosing the Distal Fusion Levels in Lenke Type 1 Adolescent Idiopathic Scoliosis: How Do the Existing Classifications and Recommendations Guide Us?

Global Spine Journal ◽

10.1177/2192568220910712 ◽

2020 ◽

pp. 219256822091071

Author(s):

Bhavuk Garg ◽

Nishank Mehta ◽

Rudra Narayan Mukherjee

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Treatment Outcomes ◽

Outcome Measures ◽

Deformity Correction ◽

Sagittal Vertical Axis ◽

Scoliosis Research Society ◽

Lenke Classification ◽

Selective Fusion ◽

Significant Difference

Study Design: Retrospective cohort. Objective: ( a) To compare the recommendations of Lenke and Peking Union Medical College (PUMC) classifications in choosing distal fusion levels in Lenke 1 adolescent idiopathic scoliosis (AIS) curves and ( b) to analyze whether the variability in distal fusion levels influences treatment outcomes. Methods: Hospital records of Lenke 1 AIS patients operated for single stage, posterior-only deformity correction were analyzed. Distal fusion levels recommended by Lenke and PUMC classifications were calculated and were compared with the actual distal fusion levels. The study population was divided based on whether the actual distal fusion levels were in agreement, shorter or longer than those recommended by Lenke classification. Subgroup analysis of Lenke 1C curves was done. The groups were compared with regard to the following outcome measures: Cobb angle correction, postoperative sagittal vertical axis, postoperative C7 offset, and Scoliosis Research Society–22r (SRS-22r) score at 24 months. Results: The distal fusion levels recommended by the 2 classifications were in agreement in 92 of 104 cases. In all the cases with disparity, Lenke classification recommended shorter fusions than the PUMC classification. No statistically significant difference was observed in the outcome measures—whether the actual distal fusion levels were in agreement, shorter, or longer than those recommended by the Lenke classification or whether or not the recommendations for selective fusion of any of these classifications were adhered to. Conclusion: Lenke classification can save fusion levels without compromising on treatment outcomes when compared with PUMC classification. Variability in choice of distal fusion levels is not clinically significant at 24-month follow-up.

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T1-weighted MR imaging of bone marrow pattern in children with adolescent idiopathic scoliosis: a preliminary study

Journal of Children s Orthopaedics ◽

10.1302/1863-2548.12.180035 ◽

2018 ◽

Vol 12 (2) ◽

pp. 181-186 ◽

Cited By ~ 3

Author(s):

S. I. Shiran ◽

L. Shabtai ◽

L. Ben-Sira ◽

D. Ovadia ◽

S. Wientroub

Keyword(s):

Bone Marrow ◽

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Diagnostic Study ◽

Level Of Evidence ◽

Lenke Classification ◽

Adjacent Disc ◽

Vertebral Bodies ◽

Preliminary Study ◽

Mri Study

Purpose Distinct normal physiological patterns of fat conversion in vertebrae were described both for children and adults. Our aim was to evaluate the T1-weighted bone marrow pattern of the vertebral bodies in various sites along the scoliotic spine of children with adolescent idiopathic scoliosis (AIS). Methods We retrospectively evaluated spine MRI studies of children with AIS. Scoliosis radiographs were assessed for type of curvature according to the Lenke classification. A paediatric neuroradiologist assessed the T1-weighted signal of vertebral bodies in comparison with the adjacent disc and distinct patterns of fatty conversion within the apical and stable vertebral bodies. Statistical assessment was performed. Results MRI study of the spines of 75 children with AIS were assessed, 59 (79%) of whom were female, with an age range of nine to 19 years. The relative overall T1-weighted signal intensity of the vertebral body bone marrow relative to the intervertebral disc was hyperintense in 76% and isointense in 24%. Fatty conversion grade of the stable vertebra was higher than the apex vertebra (p = 0.0001). A significant tendency to have more advanced fat conversion patterns in the apex vertebra up to age 13.5 years old compared with adolescents above that (p = 0.015) was seen. Conclusion This preliminary study suggests a different pattern of bone marrow conversion in AIS from the normal physiologic pattern described in the literature. Whether these changes are secondary to the biomechanics of the curved spine or may suggest that bone marrow maturation rate and content have a role in the pathogenesis of AIS remains to be further researched. Level of Evidence Level III (Diagnostic Study)

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Does Thoracic Kyphosis Have Any Importance in Selective Versus Nonselective Fusion Preference in Patients With Lenke Type 5C Adolescent Idiopathic Scoliosis? A Contribution to the Guidance of the Lenke Classification

10.21203/rs.3.rs-340655/v1 ◽

2021 ◽

Author(s):

Gökhan Karademir ◽

Kerim Sarıyılmaz ◽

Okan Özkunt ◽

Mehmet Demirel ◽

Fatih Dikici ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Sagittal Plane ◽

Treatment Preference ◽

Level Of Evidence ◽

Lenke Classification ◽

Selective Fusion ◽

The Mean ◽

Age Range

Abstract BackgroundAlthough Lenke classification analyses the sagittal plane as (+), N, and (-), it does not consider it in the choice of treatment, and it has limitations with overall thoracic kyphosis (TK). To investigate the importance of TK for treatment preference in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) by comparing radiological outcomes of the patients who underwent selective fusion (SF) or nonselective fusion (NSF). MethodsThirty-two patients with Lenke type 5C AIS were included and then divided into two groups as per the fusion procedure used in the surgical treatment. SF group including 17 patients (15 females; mean age = 16 years, age range, 14–21) with normal TK and NSF group including 15 patients (11 females; mean age = 17 years, age range, 13–26) with thoracic hyper-kyphosis. Thorocolumbar/lumbar (TL/L) Cobb, thoracic (T) Cobb, TK and lumbar lordosis (LL) were measured on standing spine radiographs preoperatively and at the final follow-up. The correction rates (CR) of each radiographic parameter were calculated.ResultsNo significant differences were observed in the mean CR of all radiographic parameters, except TK and LL correction rates. The mean CR of TK was significantly higher in NSF group (-17% [range, -100–69]) than in SF group (67% [range, 9–100]) (p = 0.000). Likewise, the mean CR of LL was found significantly higher in NSF group (12.47% [range, -100–51]) than in SF group (-2.41% [range, -75–47]) (p = 0.036).ConclusionIn patients in whom Lenke's sagittal modifier is N, SF can be performed efficiently. NSF should be preferred in those with Lenke's sagittal modifiers (+) as TK can be better controlled with NSF.Level of Evidence: 3

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