Does brace treatment impact upon the flexibility and the correctability of idiopathic scoliosis in adolescents?

Can We Stop Distally at LSTV-1 for Adolescent Idiopathic Scoliosis With Lenke 1A/2A Curves?

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine in which case one level proximal to last substantially touching vertebra (LSTV-1) could be a valid lowest instrumented vertebra (LIV), in which case distal fusion should extend to last substantially touching vertebra (LSTV), and to identify risk factors for distal adding-on.

SUMMARY OF BACKGROUND DATA

Posterior thoracic fusion to save more lumbar mobile segments has become the mainstay of operative treatment for adolescent idiopathic scoliosis (AIS) with Lenke 1A/2A curves. Although previous studies have recommended selecting the LSTV as LIV, good outcomes could still be achieved in some cases when LSTV-1 was selected as LIV.

METHODS

Ninety-four patients were included in the study with a minimum of 2-year follow-up after posterior thoracic instrumentation, in which LSTV-1 was selected as LIV. Patients were identified with distal adding-on between first erect radiographs and 2-year follow-up based on previously defined parameters. Factors associated with the incidence of adding-on were analyzed.

RESULTS

The mean follow-up duration was 37.7 ± 15.8 months. Forty patients (42.6%) with LSTV-1 selected as LIV achieved good outcomes at the last follow-up. Several preoperative risk factors significantly associated with distal adding-on were identified, including lower Risser (P = 0.001), longer thoracic curve length (P = 0.005), larger rotation and deviation of LSTV-1 (P  < 0.001), and preoperative coronal imbalance (P = 0.013).

CONCLUSION

Skeletally immature patients with long thoracic curve, preoperative coronal imbalance, large rotation, and deviation of LSTV-1 are at increased risk of distal adding-on when selecting LSTV-1 as LIV. Under this condition, distal fusion level should extend to LSTV; while in other case, LSTV-1 could be a valid LIV.Level of Evidence: 4.

A Systematic Review and Meta-analysis of Acupotomy for Scoliosis

This review investigated the effectiveness and safety of acupotomy treatment for scoliosis. There were 7 online databases used in the search from inception to March 17, 2021, for randomized controlled trials of the use of acupotomy in patients with scoliosis. The Cochrane risk-of-bias tool was used to assess the methodological quality of the studies included (n = 12). A quantitative synthesis of the randomized controlled trials was performed using RevMan Version 5.3. The effect sizes of studies were presented as mean differences for continuous outcomes and risk ratios for dichotomous outcomes, with a 95% confidence interval. As part of combined therapy, acupotomy was reported to significantly improve Cobb’s angle compared with other treatments. Likewise, the Visual Analog Scale score, the Oswestry Disability Index score, and pulmonary function were also reported to be improved following acupotomy combination therapy. Although 5 studies mentioned the criteria for reporting adverse events, only 1 study reported adverse events. In conclusion, acupotomy may be an effective treatment for scoliosis. However, the small number, and heterogeneity of the included studies, as well as the poor methodological quality, indicate that higher-quality studies should be conducted to verify the effectiveness and safety of acupotomy treatment for scoliosis.

Which thoracic curves are at the greater risk for distal adding-on: comparison between typical and atypical Lenke 1A curves

PURPOSE

To identify the characteristics and the incidence of adding-on (AO) in atypical Lenke 1A adolescent idiopathic scoliosis patients, and to investigate whether atypical and typical Lenke 1A curve should follow the same lowest instrumented vertebra (LIV) selection strategy.

METHODS

A total of 251 Lenke 1A patients who underwent posterior spinal fusion were analyzed. The minimum follow-up was 2 years. Curves were classified into two groups according to the apex. At last, 42 atypical Lenke 1A patients (apex at T10/11-T11/12) were identified and divided into atypical group (G1). Meanwhile, 42 age, gender, and Cobb angle-matched typical Lenke 1A patients (apex at T7/8-T10) were enrolled into the typical group (G2). The radiographic characteristics were evaluated, and the incidence of AO was compared between the 2 groups.

RESULTS

The incidence of atypical Lenke 1A curves was 16.7%. Patients in G1 were found to have more left thoracic curves (P = 0.029), better flexibility of thoracic (P = 0.011) and lumbar curve (P = 0.014), and more preoperative coronal imbalance (P = 0.001). At the final follow-up, G1 developed more AO (38.1% vs. 19.0%). Specificity, for patients with LIV proximal to last substantially touching vertebra (LSTV), the incidence of AO was significantly higher in G1 (82.4% vs. 42.9%, P = 0.022).

CONCLUSION

Atypical Lenke 1A curve had its own radiographic characteristics. It was more likely to develop AO when LIV was proximal to LSTV, which indicated different fusion levels should be considered in these two subtypes of Lenke 1A. We recommended LSTV as LIV in atypical Lenke 1A cases, while one level proximal to LSTV might be available in typical Lenke 1A curve.

LEVEL OF EVIDENCE

3.

Does bracing for adolescent idiopathic scoliosis affect operative results?

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

We hypothesize that preoperative bracing for idiopathic scoliosis results in increased stiffness, as measured by reduced correction on bending films, ultimately leading to decreased surgical correction. Bracing is the primary nonoperative treatment for immature AIS patients with mild to moderate curves. For patients who fail bracing and proceed to operative intervention, it is unknown whether their nonoperative treatment impacts their surgical results.

METHODS

We conducted a single-center, retrospective, comparative study on 181 consecutive adolescent idiopathic scoliosis patients, aged 11-17 years, who underwent posterior spine fusion between 2011 and 2013. Patient flexibility was measured as percent change in the curve angle of the spine from standing to supine bend. Overall curve correction was calculated as the preoperative to postoperative change in standing coronal measure divided by the preoperative measurement and reported as a percentage.

RESULTS

One hundred and twelve subjects (62%) underwent bracing prior to fusion. Braced patients had similar preoperative major Cobb angles than unbraced patients (56.5 vs 59.0, p = 0.07). Preoperatively, braced patients achieved less primary curve correction in bending films (33.6%) than unbraced patients (40.6%, p = 0.003). Postoperatively, Cobb angle correction was not different between the braced (75.7%) and unbraced group (77.2%) overall (p = 0.41). There was no difference in blood loss (p = 0.14) or surgical time (p = 0.96) between braced and unbraced groups when adjusted for surgeon and number of levels fused.

CONCLUSIONS

While braced patients may demonstrate less preoperative flexibility, there is no evidence that braced patients experience decreased curve correction compared to unbraced patients. Bracing treatment did not impact operative results, as indicated by similar Cobb angle correction, estimated blood loss, and surgical time in both groups.

LEVEL OF EVIDENCE

III.

The rotation of preoperative-presumed lowest instrumented vertebra: Is it a risk factor for distal adding-on in Lenke 1A/2A curve treated with selective thoracic fusion?

PURPOSE

To investigate whether the rotation of preoperative-presumed lowest instrumented vertebra (LIV) is a risk factor for adding-on (AO) in adolescent idiopathic scoliosis (AIS) treated with selective posterior thoracic fusion (sPTF).

METHODS

A total of 196 AIS patients of Lenke type 1A or 2A with minimum 2-year follow-up after sPTF with all pedicle screw instrumentation were included. Radiographical parameters were measured as follows: preoperative rotation angle of presumed LIV and LIV + 1, LIV + 1/LIV rotation difference, postoperative rotation angle of LIV and LIV derotation angle on CT scans. Patients were classified into AO group and non-AO group during the follow-up. The parameters were compared between the two groups to investigate risk factors for AO.

RESULTS

Among 196 patients, 40 (20.4%) patients developed with AO at the final follow-up. Compared with non-AO group, patients with AO had significantly larger preoperative rotation angle of presumed LIV (8.8° ± 3.4° vs. 3.4° ± 2.9°, P < 0.001) and LIV + 1 (5.9° ± 4.0° vs. 3.6° ± 2.9°, P = 0.004), LIV + 1/LIV rotation difference (- 2.6° ± 3.7° vs. 0.6° ± 3.2°, P < 0.001) and postoperative rotation angle of LIV (7.2° ± 4.3° vs. 3.0° ± 2.9°, P < 0.001). The last substantially touched vertebrae (LSTV) was selected as LIV in 148 patients, among which the above described parameters were found to be remarkably larger in AO group than non-AO group as well. Multivariate analysis presented Risser grade and preoperative rotation angle of presumed LIV as independent predictors of AO.

CONCLUSION

AIS patients with low Risser grade and large preoperative rotation angle of presumed LIV are more likely to develop with AO after sPTF. Moreover, for the patients with LSTV selected as LIV, preoperative rotation of presumed LIV might be still a risk factor associated with the occurrence of AO.

LEVEL OF EVIDENCE

III These slides can be retrieved under Electronic Supplementary Material.

Selecting the Last Substantially Touching Vertebra as Lowest Instrumented Vertebra in Lenke type 2A-R and 2A-L Curves

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to determine whether the last substantially touching vertebra (LSTV) can be selected as the optimal lowest instrumented vertebra (LIV) for Lenke 2A adolescent idiopathic scoliosis (AIS) with different lumbar modifiers (2A-R and 2A-L) and to investigate its relationship with the distal adding-on.

SUMMARY OF BACKGROUND DATA

Previous studies have documented good outcomes in Lenke 1A curve when LSTV was selected as LIV.

METHODS

A total of 101 female patients were included with a minimum of 2-year follow-up after selective posterior surgery. Patients were classified on the basis of the direction of L4 tilt: 2A-L and 2A-R. Patients with LSTV-1, LSTV, or LSTV+1 selected as LIV were assigned to three groups. Factors associated with adding-on were analyzed through comparison among the three groups.

RESULTS

The level of LSTV was more distal in the 2A-R group than that in the 2A-L group (P = 0.011). Distal adding-on was observed in 24 patients (23.8%). In the 2A-R curves, 26.1% patients were found to have adding-on. The incidence of adding-on was significantly higher in LSTV-1 than LSTV or LSTV+1 group. Logistic regression analysis showed the distance between LIV and LSTV (LIV-LSTV <0) was the independent factor associated with adding-on (odds ratio [OR] = 8.7, 95% confidence interval [CI] = 3.1-45.5, P = 0.011). In the 2A-L curves, 21.8% patients were found to have adding-on. The incidence of adding-on was significantly lower in LSTV+1 than LSTV-1 or LSTV group. Similarly, logistic regression showed the distance between LIV and LSTV (LIV-LSTV ≤0) had significant association with adding-on (OR = 11.9, 95% CI = 2.5-53.2, P = 0.009).

CONCLUSION

The distance between LIV and LSTV was a significant factor associated with adding-on for both 2A-R and 2A-L patients. The rule of selecting LIV should be different between 2A-R and 2A-L curves. We recommend to extend the fusion level to LSTV in 2A-R curve and to LSTV+1 in 2A-L curve to avoid distal adding-on.

LEVEL OF EVIDENCE

3.

Where to stop distally in Lenke modifier C AIS with lumbar curve more than 60°: L3 or L4?

OBJECTIVE

Selecting lowest instrumented vertebra (LIV) in adolescent idiopathic scoliosis (AIS) with large lumbar curve can be difficult. Stopping the distal fusion at L3 could save more mobile lumbar segments but may increase the risk of decompensation. This study was designed to evaluate preoperative radiographic factors that were associated with the selection of either L3 or L4 as LIV in posteriorly treated AIS patients with large lumbar curve.

PATIENTS AND METHODS

A total of 84 AIS patients with lumbar curve >60° were analyzed with a minimum of 2-year follow-up after posterior instrumentation with lumbar curves included in fusion. Patients were grouped according to the selection of LIV, either L3 or L4 group. All radiograph parameters were measured pre- and post-operatively including Cobb angle, lumbar flexibility, L3 translation and rotation on posteroanterior (PA) and side-bending (SB) film, etc. The SRS-22 score was used to assess clinical outcomes. Radiographic and clinical parameters were compared between the two groups.

RESULTS

There were 24 patients in L3 group and 60 patients in L4 group. At last follow-up, no difference was found in the clinical and radiographic parameters between the two groups. Preoperatively, the L3 group had lower L3 translation on PA view, L3 translation on concave SB film, L3 rotation on convex SB film, more L3/4 disc opening on convex SB film and larger lumbar flexibility. Multivariate regression found L3 translation on concave SB film was the single most important predictor of LIV selection. Specifically, L3 translation on concave SB film <10 mm was a potential threshold for selecting L3 as LIV.

CONCLUSIONS

For AIS patients with large lumbar curve, instrumentation can be reliably stopped at L3 if L3 translation on preoperative concave SB film was less than 10 mm, with the same radiographic and clinical outcomes as fusing to L4.

Effect of Preoperative SpineCor® Treatment on Surgical Outcome in Idiopathic Scoliosis: An Observational Study

Background

Idiopathic scoliosis is a three-dimensional deformity of the spine. We investigated the effect of preoperative treatment with SpineCor^® dynamic brace on the efficiency of surgical correction from a posterior approach in adolescent idiopathic scoliosis.

Material/Methods

This was a retrospective observational study. Participants were 53 girls who underwent surgery from posterior approach due to idiopathic adolescent scoliosis, divided into a study group (Group A, 27 girls) and a control group (Group B, 26 girls). Girls in the study group had previously undergone treatment with the SpineCor^® brace. Outcome measures were amount of correction and coronal balance based on anteroposterior plain radiographs obtained prior to surgery, at 1 week after surgery, and at 12 months after surgery.

Results

In both groups, satisfactory deformity correction was achieved after surgery (Group A, 73%±12 vs. Group B, 68%±16) and at 12-month follow-up (75%±12 vs. 68%±12, respectively), with no statistically significant differences identified. Directly after surgery, patients preoperatively treated with the SpineCor^® brace displayed smaller coronal balance deviation compared with the preoperative measurement, with significant differences in the outcome achieved at 1 week after surgery in Group B. At 12-month follow-up, both groups had significant coronal balance improvement.

Conclusions

This is the first study assessing the effect of dynamic brace treatment on scoliosis surgery. The study shows that a history of preoperative treatment with the SpineCor^® dynamic brace does not affect the amount of the achieved correction of AIS directly after surgery or at 12-month follow-up, but it does facilitate faster restoration of normal coronal balance.

Selective thoracic fusion for adolescent thoracic scoliosis secondary to Chiari I malformation: a comparison between the left and the right curves

PURPOSE

The aim of this study was to compare the clinical outcomes of selective thoracic fusion in the surgical treatment of Chiari malformation type I (CMI) adolescents with different curve patterns.

METHODS

Sixty-three CMI patients with left thoracic curve (LTC) and 63 age- and curve-magnitude-matched CMI patients with right thoracic curve (RTC) were recruited. Selective thoracic fusion was performed for two groups. The coronal and sagittal parameters including the thoracic and lumbar Cobb angle, apical vertebral translation, trunk shift, thoracic kyphosis (TK), lumbar lordosis and sagittal vertical axis were measured before surgery, immediately postoperative and at the final follow-up. The accuracy of pedicle screw placement between both groups was also compared.

RESULTS

All preoperative radiographic parameters were matched in both groups except for TK (LTC group 40.1° vs. RTC group 23.0°, P = 0.021). The immediately postoperative spontaneous correction of the lumbar curve was 56.9% in LTC group, which was remarkably lower than in RTC patients (67.9%). Patients with LTC were found to have obviously increased trunk shift than those with RTC (15.1 mm vs. 8.0 mm, P = 0.038). At the final follow-up, the correction of the thoracic curve was comparable between the two groups (59.9% vs. 62.6%, P = 0.610). The rate of the pedicle screw perforations was similar between both groups.

CONCLUSIONS

Patients with LTC and RTC can both be successfully corrected through selective thoracic fusion with a promising long-term surgical outcome. CMI patients with RTC tend to have a better spontaneous correction of the lumbar curve after surgery. These slides can be retrieved under Electronic Supplementary Material.

Quality of life and patient satisfaction in bracing treatment of adolescent idiopathic scoliosis

BACKGROUND

Bracing is used as a valid non-surgical treatment for adolescent idiopathic scoliosis (AIS) to avoid progression of the deformity and thereby surgery. The effect of bracing treatment on quality of life of patients with AIS has been a topic of interest in the international literature. The aim of this study was to evaluate the quality of life and patient satisfaction during bracing treatment for AIS of a pediatric hospital.

MATERIAL AND METHOD

We assessed a total of 43 non-consecutive female patients (mean age at questionnaire, 13 years and 1 month and 10 years and 8 months to 14 years and 5 months; mean period of usage of brace, 1 year and 7 months), with adolescent idiopathic scoliosis (AIS), older than 10 years of age until skeletal maturity, with a Risser sign less than 3 and scoliosis between 20 and 45°, treated with thoracolumbosacral orthosis (TLSO) for a period longer than 6 months, and without other comorbidities or previous surgeries, were evaluated. The patients were administered a previously validated to Spanish questionnaire on quality of life (Brace Questionnaire (BrQ); Grivas TB et al.). BrQ is a validated tool and is considered a disease-specific instrument; its score ranges from 20 to 100 points, and higher BrQ scores are associated with better quality of life.

RESULTS

The patients reported using the brace for a mean of 17.6 h daily and for a mean period of 1 year and 7 months at the time of the study. Overall, 72% of the study population reported to be in some way psychologically affected by the brace wearing, 56% felt their basic motor activities were affected, 54% felt socialization with their environment was affected, 46% considered their quality of life deteriorated due to pain, and 40% reported conflicts in the school environment.

CONCLUSION

Patients with AIS treated with bracing reported a negative impact (53.5% overall) on quality of life and treatment satisfaction in terms of psychological, motor, social, and school environment aspects. An interdisciplinary approach would be important for the integrated psychosocial care of these patients.

Patterns of coronal curve changes in forward bending posture: a 3D ultrasound study of adolescent idiopathic scoliosis patients

PURPOSE

The Adam's forward bending test is the most commonly used approach to assess the spine deformity in adolescent idiopathic scoliosis (AIS) patients. However, there are noticeable differences in the hump appearance from standing to forward bending. This phenomenon has yet to be understood due to limitations of conventional radiographs. This study aimed to investigate effects of postural change in the spine deformity in the coronal plane of AIS patients using a 3D ultrasound imaging system.

METHODS

This was a prospective study that recruited 72 AIS patients at a single institute. All patients were scanned twice in the sitting and sitting forward bending postures. A coronal ultrasound image showing the spinal curvature was generated after each scan and the spinous process angle (SPA) representing the deformity was manually measured from it. Correlation of SPAs under sitting and sitting forward bending postures was analyzed.

RESULTS

In the comparison test, it was noted that there were three types of spine profile alternation after the postural change. In types I and II, the SPA angle numbers were the same before and after forward bending and only SPA values changed. In type III, the two curvatures were changed to one curvature in the forward bending posture. Moderate correlation was observed between the angles obtained in the two postures (r = 0.55, p < 0.001).

CONCLUSIONS

Spine deformities of AIS patients vary with different postures. The patterns of changes in sitting and sitting forward bending postures are highly subject dependent. These slides can be retrieved under Electronic Supplementary Material.

Selecting the LSTV as the Lower Instrumented Vertebra in the Treatment of Lenke Types 1A and 2A Adolescent Idiopathic Scoliosis: A Minimal 3-year Follow-up

STUDY DESIGN

Retrospective study.

OBJECTIVE

The purpose of this study was to verify the last substantially touched vertebra (LSTV) as the ideal lower instrumented vertebra (LIV) and to identify predictive factors of adding-on in patients with Lenke type 1A and 2A curve patterns when LSTV was chosen as the LIV.

SUMMARY OF BACKGROUND DATA

Although several studies have indicated that the use of the LSTV as the LIV can obtain favorable outcomes in Lenke 1A and 2A curves, the factors identifying patients with Lenke 1A and 2A curve patterns who should undergo a fusion extending beyond the LSTV have not been identified.

METHODS

A total of 120 patients with Lenke 1 and 2 curves after posterior instrumentation and fusion to the LSTV were evaluated. All patients had a minimum 3-year follow-up. Patients were grouped based on the occurrence of the distal adding-on phenomenon: an adding-on group and a no adding-on group. We analyzed the significant independent factors associated with adding-on via univariate analysis and then via stepwise logistic regression analysis.

RESULTS

Distal adding-on was observed in 16 patients (13.33%). Binary logistic regression analysis showed that the Risser sign (OR = 0.592, P = 0.033), preoperative distance between the LIV and the center sacral vertical line (CSVL) (LIV-CSVL) (OR = 1.286, P = 0.002), and postoperative thoracic kyphosis (T5-T12) (OR = 0.784, P = 0.002) were primary factors for distal adding-on.

CONCLUSION

Selecting the LSTV as the LIV simplifies the selection of the LIV and is an effective operation strategy in patients with Lenke 1A and 2A curve types. Patients with lower Risser sign, larger preoperative LIV-CSVL, and postoperative thoracic hypokyphosis are more likely to develop distal adding-on at 3-year follow-up.

LEVEL OF EVIDENCE

4.

Natural History of Postoperative Adding-On in Adolescent Idiopathic Scoliosis: What Are the Risk Factors for Progressive Adding-On?

Purpose

To investigate the natural history of distal adding-on in adolescent idiopathic scoliosis (AIS) and to identify risk factors for its progression.

Methods

Sixty-one AIS patients with distal adding-on occurrence were included. We further classify distal adding-on into progressive and nonprogressive group according to its natural evolution. The first radiograph indicating initiation of adding-on (primary adding-on) and the last follow-up radiograph were compared in terms of the deviation of the first vertebra below instrumentation from the CSVL and the angulation of the first disc below instrumentation. Compared to primary adding-on, progressive adding-on was defined as a further increase of deviation > 5 mm or a further increase of angulation > 5°. Risk factors associated with the progression of adding-on were analyzed.

Results

Among 61 patients diagnosed with distal adding-on, 24 (39.3%) were progressive and 37 (60.7%) were nonprogressive. Lower Risser grade, open triradiate cartilage, and lowest instrumented vertebra (LIV) proximal to Substantially Stable Vertebra (SSV) were found to be significantly associated with the progressive adding-on. Besides, the distal adding-on was more likely to progress for patients with higher left shoulders than right ones after surgery.

Conclusions

The risk factors for the progression of adding-on included skeletal immaturity, LIV proximal to SSV, and higher left shoulders after surgery.

Spinal Flexibility Assessment on the Patients With Adolescent Idiopathic Scoliosis: A Literature Review

STUDY DESIGN

A literature review.

OBJECTIVE

The aim of this study was to review the contemporary methods for spinal flexibility assessment on the patients with adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Spinal flexibility is one of the essential parameters for clinical decisions on the patients with AIS. Various methods of spinal flexibility assessment are proposed, but which method(s) could better reveal spinal flexibility or predict treatment effect is unclear.

METHODS

The databases of AbleData, IBSS, Academic Search Premier, MEDLINE/PubMed, CINAHL, Recal Legacy, REHABDATA, Embase, and Web of Science were searched. The study inclusive criteria were (1) prospective cohort study; (2) investigated spinal flexibility on AIS patients; (3) published in English 1996 to 2016.

RESULTS

Totally 15 articles were included and 11 methods of spinal flexibility assessment were introduced in this review. Traction methods revealed higher spinal flexibility on the patients with severe curves (>65°) but lower spinal flexibility on the patients with moderate curves (40°-65°), comparing with lateral bending methods. Among lateral bending methods, fulcrum bending flexibility is higher on thoracic (T) curves, whereas supine with lateral bending flexibility is higher on thoracolumbar or lumbar (TL/L) curves. For predicting postoperative correction, fulcrum bending flexibility showed higher correlation with postoperative correction on moderate curves and traction flexibility showed higher correlation on severe curves, compared with supine with lateral bending method.

CONCLUSION

Curve magnitude and location are two important parameters in selecting appropriate method for spinal flexibility assessment and treatment effect prediction. The traction method should be considered for the patients with severe curves, while the lateral bending method is suggested for the patients with moderate curves. The fulcrum bending method is recommended to assess T curve flexibility, whereas the supine with lateral bending method is for the assessment of TL/L curve flexibility. A comprehensive guideline for selecting spinal flexibility assessment method(s) should be established via future studies.

LEVEL OF EVIDENCE

4.

Comparison of Surgical Outcome of Adolescent Idiopathic Scoliosis and Young Adult Idiopathic Scoliosis: A Match-Pair Analysis of 160 Patients

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate if the surgical outcome of young adults was equivalent to adolescents for surgical correction of thoracic adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Despite numerous reports on the satisfactory surgical correction, some AIS patients or families still have the assumption that delay of surgery into young adulthood may be more beneficial. Hence, the strict paired analysis of clinical outcome between AIS and adult idiopathic scoliosis (AdIS) is required, which lacks report in the current literature.

METHODS

This is a retrospective 1:1 matched cohort. A total of 80 pairs were recruited with the following inclusion criteria: (A) female Lenke Type 1A or 1B idiopathic scoliosis; (B) selective fusion; (C) adolescents aged 10 to 18 years and young adults aged 19 to 29 years; (D) one-stage posterior approach; (E) all-pedicle-screws instrumentations; (F) major Cobb angle 45° to 80°. AIS patients and AdIS patients were matched for apex, major thoracic curve magnitude (±5°), lumbar curve magnitude (±5°), time of surgery (±6 month), and follow-up (±6 month).

RESULTS

The age at the time of surgery in AdIS patients averaged 22.21years, significantly larger than that of AIS patients (22.21 vs. 14.47 yr). AdIS patients had significant lower curve flexibility. Accordingly, lower correction rate and larger postoperative main Cobb angle were found in AdIS patients. Regarding quality of life, no significant difference was observed between the two groups during follow-up.

CONCLUSION

The results may provide evidence for spine surgeons to communicate with AIS patients and their families regarding pros and cons of the delay of surgery into young adulthood. AIS patients would gain better radiographic curve correction compared with matched AdIS patients due to more flexibility. When considering potential curve progression, the radiographic outcome of AdIS may be even worse. Whereas delaying to adulthood may have similar health-related quality of life and reduce the risk of adding-on phenomenon.

LEVEL OF EVIDENCE

3.

Initial Correction Rate Can be Predictive of the Outcome of Brace Treatment in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine the definite cut-off value of initial correction rate (ICR) that could be predictive of bracing outcome in patients with adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Earlier studies showed that braced patients with a better ICR could finally have a higher probability of successful outcome. However, it remains controversial what definitive cut-off value of ICR is required to accurately predict the outcome.

MATERIALS AND METHODS

A cohort of 488 adolescent idiopathic scoliosis patients who have completed the brace treatment with a minimum of 2-year follow-up were included in the current study. Curve progression of ≤5 degrees was used to define the success of brace treatment. The success group and the failure group were compared in terms of initial Risser sign, initial age, sex, curve pattern, initial curve magnitude, and ICR. The receiver operating characteristics curve was used to define the definite cut-off point of initial curve correction rate. A logistic regression model was created to determine the independent predictors of the bracing outcome.

RESULTS

At the beginning of brace treatment, the mean age of the cohort was 13.2±1.5 years, and the mean curve magnitude was 29.5 ± 6.6 degrees. At the final follow-up, 368 patients were successfully treated by bracing. Compared with the success group, the failure group was found to have significantly younger age, lower Risser sign, and lower ICR. According to the receiver operating characteristic curve, the best cut-off value of ICR was 10%. The logistic regression model showed that ICR was significantly associated with the outcome of brace treatment with an odds ratio of 9.61.

CONCLUSIONS

Patients with low ICR, low Risser sign, and young age could have a remarkably high risk of bracing failure. A rate of 10% was the optimal cut-off point for ICR, which can be used to effectively stratify braced patients.

Do the disc degeneration and osteophyte contribute to the curve rigidity of degenerative scoliosis?

Background

The factors associated with lateral curve flexibility in degenerative scoliosis have not been well documented. Disc degeneration could result in significant change in stiffness and range of motion in lateral bending films. The osteophytes could be commonly observed in degenerative spine but the relationship between osteophyte formation and curve flexibility remains controversial. The aim of the current study is to clarify if the disc degeneration and osteophyte formation were both associated with curve flexibility of degenerative scoliosis.

Methods

A total of 85 patients were retrospectively analyzed. The inclusion criteria were as follow: age greater than 45 years, diagnosed as degenerative scoliosis and coronal Cobb angle greater than 20°. Curve flexibility was calculated based on Cobb angle, and range of motion (ROM) was based on disc angle evaluation. Regional disc degeneration score (RDS) was obtained according to Pfirrmann classification and osteophyte formation score (OFS) was based on Nanthan classification. Spearman correlation was performed to analyze the relationship between curve flexibility and RDS as well as OFS.

Results

Moderate correlation was found between RDS and curve flexibility with a Spearman coefficient of −0.487 (P = 0.009). Similarly, moderate correlation was observed between curve flexibility and OFS with a Spearman coefficient of −0.429 (P = 0.012). Strong correlation was found between apical ROM and OFS compared to the relationship between curve flexibility and OFS with a Spearman coefficient of −0.627 (P < 0.001).

Conclusions

Both disc degeneration and osteophytes formation correlated with curve rigidity. The pre-operative evaluation of both features may aid in the surgical decision-making in degenerative scoliosis patients.

Low body mass index can be predictive of bracing failure in patients with adolescent idiopathic scoliosis: a retrospective study

PURPOSES

To determine the relationship between low body mass index (BMI) and the outcome of brace treatment in patients with adolescent idiopathic scoliosis (AIS).

METHODS

350 braced female AIS patients were included in this study. The baseline characteristics of the patient were recorded at their first visit, including age, Risser sign, digital skeletal age, BMI, curve pattern, and curve magnitude. Underweight was defined as lower than the 5th percentile of the sex- and age-specific BMI. The treatment was considered as a failure if the curve progressed more than 5°, or if patients underwent surgery. According to the final outcome of brace treatment, the cohort was divided into the success group and the failure group. A logistic regression model was created to determine the independent predictors of the bracing outcome.

RESULTS

24.5% (86/350) of the patients were identified as underweight at their initial visit, which was significantly higher than the rate of 13.1% (46/350) at the final follow-up (p < 0.001). At the initial visit of the patients, the rate of underweight was 17.6% (45/255) in the success group, which was significantly lower than the rate of 43.1% (41/95) in the failure group (p < 0.001). Logistic regression analysis showed that low BMI was significantly associated with bracing failure (p < 0.001).

CONCLUSION

The low BMI could be predictive of bracing failure in AIS patients, which should be taken into account when surgeons prescribe brace treatment to such patients.

The effect of scoliotic deformity on spine kinematics in adolescents

BACKGROUND

While adolescent idiopathic scoliosis (AIS) produces well characterized deformation in spinal form, the effect on spinal function, namely mobility, is not well known. Better understanding of scoliotic spinal mobility could yield better treatment targets and diagnoses. The purpose of this study was to characterize the spinal mobility differences due to AIS. It was hypothesized that the AIS group would exhibit reduced mobility compared to the typical adolescent (TA) group.

METHODS

Eleven adolescents with right thoracic AIS, apices T6-T10, and eleven age- and gender-matched TAs moved to their maximum bent position in sagittal and coronal plane bending tasks. A Trakstar (Ascension Technologies Burlington, VT) was used to collect position data. The study was approved by the local IRB. Using MATLAB (MathWorks, Natick, MA) normalized segmental angles were calculated for upper thoracic (UT) from T1-T3, mid thoracic (MT) from T3-T6, lower thoracic (LT) from T6-T10, thoracolumbar (TL) from T10-L1, upper lumbar (UL) from L1-L3, and thoracic from T1-L1 by subtracting the standing position from the maximum bent position and dividing by number of motion units in each segment. Mann Whitney tests (α = 0.05) were used to determine mobility differences.

RESULTS

The findings indicated that the AIS group had comparatively increased mobility in the periapical regions of the spine. The AIS group had an increase of 1.2° in the mid thoracic region (p = 0.01) during flexion, an increase of 1.0° in the mid thoracic region (p = 0.01), 1.5° in the thoracolumbar region (p = 0.02), and 0.7° in thoracic region (p = 0.04) during left anterior-lateral flexion, an increase of 6.0° in the upper lumbar region (p = 0.02) during right anterior-lateral flexion, and an increase of 2.2° in the upper lumbar region during left lateral bending (p < 0.01).

CONCLUSIONS

Participants with AIS did not have reduced mobility in sagittal or coronal motion. Contrarily, the AIS group often had a greater mobility, especially in segments directly above and below the apex. This indicates the scoliotic spine is flexible and may compensate near the apex.

Effectiveness of Selective Thoracic Fusion in the Surgical Treatment of Syringomyelia-associated Scoliosis: A Case-control Study With Long-term Follow-up

STUDY DESIGN

A retrospective case-control studyOBJECTIVE.: The aim of the study was to investigate the effectiveness of selective thoracic fusion in the surgical treatment of patients with syringomyelia-associated scoliosis.

SUMMARY OF BACKGROUND DATA

Selective thoracic fusion technique was introduced to treat idiopathic scoliosis patients with major thoracic curve. Theoretically, such therapeutic philosophy could be applied to syringomyelia patients. There is no previous study that specifically addresses the effectiveness of selective thoracic fusion in patients with syringomyelia-associated scoliosis.

METHODS

Two groups of scoliosis patients were enrolled, including 52 patients with syringomyelia-associated scoliosis and 52 patients with adolescent idiopathic scoliosis. Selective thoracic fusion was performed for both groups. Radiographic parameters including Cobb angle, apical vertebral translation, trunk shift, thoracic kyphosis (TK), lumbar lordosis, and sagittal vertical axis were measured on the standing posteroanterior and lateral radiographs before surgery, 1 week postoperatively and at the final follow-up, respectively. Inter- and intragroup comparisons were performed for each variable.

RESULTS

Patients of the two groups were matched in terms of age, sex, fusion levels, duration of follow-up, and all preoperative radiographic parameters except for TK. At the final follow-up, the coronal correction of the thoracic curve was comparable between the two groups (58.8 ± 10.2% vs. 61.3 ± 8.7%, P = 0.25). Moreover, the two groups were observed to have a similar improvement of lumbar curve (62.4 ± 7.3% vs. 64.9 ± 6.9%, P = 0.33). The mean correction loss of thoracic curve and lumbar curve in syringomyelia group were 3.6 ± 3.2% and 5.3 ± 1.8% respectively, showing no statistical difference when compared with those of adolescent idiopathic scoliosis group. The sagittal spinal alignments of the two groups, including TK and lumbar lordosis, were similarly maintained during the follow-up.

CONCLUSION

Syringomyelia-associated scoliosis can be successfully corrected through selective thoracic fusion surgery with a promising long-term surgical outcome.

LEVEL OF EVIDENCE

3.

Selecting the Last "Substantially" Touching Vertebra as Lowest Instrumented Vertebra in Lenke Type 1A Curve: Radiographic Outcomes With a Minimum of 2-year Follow-Up

STUDY DESIGN

Retrospective study.

OBJECTIVE

To compare the long-term outcomes of correction surgery for Lenke 1A scoliosis patients among those with non-Substantially Touched Vertebra (nSTV), nSTV+1, or STV selected as lowest instrumented vertebra (LIV).

SUMMARY OF BACKGROUND DATA

Previous studies have documented good outcomes when last touching vertebra (LTV) was selected as LIV; however, it is sometimes confusing to determine the proper LTV when central sacral vertical line (CSVL) slightly touches the vertebra.

METHODS

A total of 104 patients were included in the study with a minimum of 2-year follow-up after selective posterior thoracic instrumentation. STV was defined as the LTV where CSVL was between the pedicles or touching the pedicle. nSTV was defined as the LTV where CSVL was touching the corner of the vertebra lateral to the pedicle border. Patients with nSTV, nSTV+1, or STV selected as LIV were assigned to three groups with clinical outcomes compared among them. Factors associated with the incidence of adding-on were analyzed.

RESULTS

Distal adding-on was observed in 23 patients (22.1%). The incidence of distal adding-on was significantly higher in nSTV group than STV group or nSTV+1 group. Several risk factors significantly associated with adding-on were identified, including the distance between LIV and STV/nSTV+1, preoperative proximal thoracic curve and sagittal vertical axis, postoperative lumbar lordosis, apical translation, trunk shift, and radiographical shoulder height. Logistic regression analysis showed that the distance between LIV and STV/nSTV+1 (LIV-STV <0 or LIV-(nSTV+1) <0) was the only independent factor associated with the incidence of adding-on (odds ratio = 27.1, 95% confidence interval = 2.3-311.2, P = 0.002).

CONCLUSION

Differentiating STV from nSTV properly can facilitate the determination of optimal LIV and decrease the incidence of distal adding-on. Selecting STV or nSTV+1 as LIV could yield a promising outcome for Lenke 1A scoliosis patients undergoing selective posterior thoracic fusion.

LEVEL OF EVIDENCE

3.

Median effective effect-site concentration of sufentanil for wake-up test in adolescents undergoing surgery: a randomized trial

BACKGROUND

To determine the median effective concentration of sufentanil as an analgesic during wake-up tests after sevoflurane anesthesia during surgery for adolescent idiopathic scoliosis (AIS).

METHODS

This is a randomised controlled trial. Sixty patients aged 13-18 years scheduled for AIS surgery were randomized into six groups of 10 patients each to receive target effect-site concentrations of sufentanil of 0.19, 0.1809, 0.1723, 0.1641, 0.1563, and 0.1489 ng/ml (target concentration ratio, 1.05). Wake-up time was recorded. Median EC50 and 95% confidence interval (CI) for sufentanil target-controlled infusion (TCI) were determined using Kärber's method. The primary outcome was median EC50 for sufentanil TCI as an analgesic during the wake-up test after sevoflurane anesthesia during surgery for AIS.

RESULTS

The EC50 and 95% CI of sufentanil TCI were 0.1682 ng/ml and 0.1641 ~ 0.1724 ng/ml, respectively.

CONCLUSIONS

The EC50 of sufentanil TCI was 0.1682 ng/ml (95% CI: 0.1641 ~ 0.1724 ng/ml) during sevoflurane anesthesia in adolescents undergoing surgery for idiopathic scoliosis with intraoperative wake-up tests.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: ChiCTR-TTRCC-12002696.

Effect of a spinal brace on postural control in different sensory conditions in adolescent idiopathic scoliosis: a preliminary analysis

BACKGROUND

Despite the positive effects of spinal braces on postural stability, they may constrain movement, resulting in poor balance control in patients with adolescent idiopathic scoliosis (AIS). Therefore, assessment of postural dynamics may aid in designing new less-constraining braces.

OBJECTIVES

The effects of a spinal brace on postural stability and Cobb angle were investigated in this study.

METHODS

Thirteen pediatric patients (10 females, three males) with AIS were recruited to participate in the study. Cobb angle was assessed by X-ray analyses, and postural stability was tested by computerized dynamic posturography in braced and unbraced conditions. A polyethylene underarm corrective spinal brace was fabricated for the subjects.

RESULTS

Thoracic and lumbar curvature decreased to 18.88 ± 11.73° and 17.70 ± 10.58°, respectively, after bracing (p < 0.05). Lower equilibrium scores were observed in the "eyes closed" condition and higher scores in the "eyes closed with a swaying support" condition; higher composite equilibrium scores were also observed for the sensory organization test (p < 0.05) in the braced condition. Lower scores were observed for the "toes-up adaptation test" in the braced condition (p < 0.05). In the braced condition, the reaction time was slower in the right-backward direction and movement velocity was higher in the right-front direction on the limits of stability test (p < 0.05). Furthermore, lower on-axis velocity during forward/backward dynamic balance control was observed in the braced condition (p < 0.05).

CONCLUSIONS

Wearing a spinal brace improved postural stability in terms of increased proprioception, equilibrium performance, and rhythmic movement ability in patients with AIS.

Does delaying surgery in immature adolescent idiopathic scoliosis patients with progressive curve, lead to addition of fusion levels?

PURPOSE

To analyze the changes in the curve extent, pattern and the fusion level in adolescent idiopathic scoliosis (AIS) patients who undergo delayed surgery instead of early surgery.

METHODS

Thirty-five immature AIS patients whose radiographs demonstrated an initial primary curve of more than 40° with a subsequent increase of 10° before attaining skeletal maturity with brace were enrolled. The initial and the final radiographs taken before surgery were compared to assess the changes in curve extent, pattern and the fusion levels as recommended by King's, Lenke's and Suk's guidelines.

RESULTS

The average age of 35 AIS patients was 12.7 ± 1.6 years. The time interval between initial and final radiography was 39.3 ± 20.2 months and the degree of progress of the primary curve was 13 ± 9.7°. Fusion levels changed in 33 (94.2%), 33 (94.2%) and 32 (91.4%) patients according to King's, Lenke's and Suk's guidelines, respectively. Curve pattern was changed in 2 (5.7%), 12 (34.3%) and 10 (28.6) patients by King's, Lenke's and Suk's guidelines. The mean number of levels requiring fusion increased from 9.4 ± 2.1 at initial visit to 11.1 ± 1.8 at the final follow-up using King's guidelines, 9.7 ± 2.2-11.6 ± 2.0 as per Lenke's guidelines and 9.1 ± 2.0-11.5 ± 2.3 when fusion was planned using Suk's guidelines (p < 0.001 in all guidelines).

CONCLUSIONS

Delay of surgery in immature AIS patients whose Cobb's angle exceed 40° initially and showing subsequent progression of the curve, of more than 10° can lead to alterations in the curve pattern and the need for increase in fusion levels.