Hybrid versus total sublaminar wires in patients with spinal muscular atrophy undergoing scoliosis surgery

Background Early versions of spinal muscular atrophy (SMA) scoliosis correction surgery often involved sublaminar devices. Recently, the utilization of pedicle screws has gained much popularity. Pedicle screws are generally believed to provide additional deformity correction, but pedicle size and rotational deformity limit their application in the thoracic spine, resulting in a hybrid construct involving pedicle screws and sublaminar wire. Studies of the efficacy of hybrid instrumentation in SMA scoliosis are often limited by the scarcity of the disease itself. In this study, we aimed to compare the surgical outcomes between hybrid constructs involving pedicle screws and sublaminar wire and sublaminar wire alone in patients with SMA scoliosis. Methods We retrospectively reviewed the clinical records and radiographic assessments of patients with SMA scoliosis who underwent corrective surgery between 1993 and 2017. The radiographic assessments included deformity correction and progressive changes in the major curve angle, pelvic tilt (PT) and coronal balance (CB). The correction of deformities was observed postoperatively and at the patient’s 2-year follow-up to test the efficacy of each type of construct. Results Thirty-three patients were included in this study. There were 14 and 19 patients in the wiring and hybrid construct groups, respectively. The hybrid construct group demonstrated a higher major curve angle correction (50.5° ± 11.2° vs. 36.4° ± 8.4°, p < 0.001), a higher apical vertebral rotation correction (10.6° ± 3.9° vs. 4.8° ± 2.6°, p < 0.001), and a reduced progression of the major curve angle at the 2-year follow-up (5.1° ± 2.9° vs. 8.7° ± 4.8°, p < 0.001). A moderate correlation was observed between the magnitude of correction of the apical vertebral rotation angle and the major curve (r = 0.528, p = 0.002). Conclusion This study demonstrated that hybrid instrumentation can provide a greater magnitude of correction in major curve and apical rotation as well as less major curve progression than sublaminar wire instrumentation alone in patients with SMA scoliosis. Level of evidence III

Gerinckorrekciós műtétek háromdimenziós hatékonysági vizsgálata serdülőkori idiopathiás gerincferdülésben

Összefoglaló. Bevezetés: Nincs egységesen elfogadott álláspont, hogy a serdülőkori idiopathiás gerincferdülés sebészi korrekcióját melyik életkorban optimális elvégezni. Világszerte 11 éves kortól akár (kezeletlen esetben) 50–60 éves korig végeznek fúziós műtétet a betegségben, 63–83%-os átlagos koronális síkú korrekciós hatékonysággal. Célkitűzés: Célul tűztük ki, hogy felmérjük a gerinckorrekciós műtétek hatékonyságát három dimenzióban, illetve a páciens életkorának függvényében. Módszerek: A vizsgálatba 23, serdülőkori idiopathiás gerincferdüléssel diagnosztizált beteget (12 fő 17 évnél fiatalabb, 11 fő 17 évnél idősebb) vontunk be. Minden betegnél csavaros derotációt és spondylodesist végeztünk, és a beavatkozás előtt és után EOS 2D/3D felvételeket, majd sterEOS 3D rekonstrukciókat készítettünk. A következő paramétereket számítottuk: Cobb-fok, háti kyphosis, ágyéki lordosis, apicalis csigolyarotáció, maximális csigolyarotáció. A különböző életkorú csoportok közötti különbséget kétmintás t-próbával, illetve Wilcoxon-féle próbával vizsgáltuk. Eredmények: A gerinckorrekciós műtétek során a koronális síkú eltérést 78,2%-ban (átlagosan 55,1 Cobb-fokról 12,0 Cobb-fokra), az apicalis csigolyarotációt 56,7%-ban (átlagosan 21,0 fokról 9,1 fokra) tudtuk korrigálni. A 17 éves életkor után operált páciensek esetén átlagosan 79,2%-os Cobb-fok-csökkenést értünk el, míg a fiatalabb betegcsoportban 77,0%-ban korrigáltuk a koronális főgörbületet (p = 0,614). Az idősebb betegcsoportban szignifikánsan kevésbé sikerült az apicalis csigolyarotáció korrekciója (átlagosan 38,1%; 21,8 fokról 12,4 fokra), mint a fiatalabb pácienseknél (átlagosan 68,5%; 20,2 fokról 6,2 fokra; p = 0,016). Következtetés: Összességében a nemzetközi publikációknak megfelelő korrekciót értünk el. A koronális síkban közel azonos korrekciós hatékonyság figyelhető meg a különböző életkorú betegcsoportok között, a csigolyarotáció azonban 17 éves életkor előtt hatékonyabban korrigálható. Orv Hetil. 2021; 162(39): 1573–1578. Summary. Introduction: There is no clear recommendation for the optimal age to perform corrective surgery in adolescent idiopathic scoliosis. Fusion surgery is performed from the age of 11 to 50–60 years, with an average coronal plane correction efficiency of 63–83%. Objective: We aimed to evaluate the effectiveness of correction surgeries in three dimensions in adolescent idiopathic scoliosis. In addition, our objective was to examine the influence of the patient’s age on the correction. Methods: The study included 23 patients with adolescent idiopathic scoliosis (12 patients younger than 17 years, 11 patients older than 17 years). All patients underwent screw-derotation and spondylodesis and underwent EOS 2D/3D imaging before and after the operation, followed by sterEOS 3D reconstructions. The following parameters were calculated: Cobb degree, thoracic kyphosis, lumbar lordosis, apical vertebral rotation, maximal vertebral rotation. Differences between different age groups were examined by paired-sample t-test and Wilcoxon rank sum test. Results: The mean efficiency of correction surgeries was 78.2% in the coronal plane (from an average of 55.1 Cobb degrees to 12.0 Cobb degrees) and 56.7% in the axial plane (from an average of 21.0 degrees to 9.1 degrees). We achieved an average 79.2% reduction of Cobb angle in patients operated after the age of 17 years, which was 77.0% in the younger group (p = 0.614). Apical vertebral rotation correction was significantly less successful in the elderly group (mean 38.1%; from 21.8 degrees to 12.4 degrees) than in patients operated before the age of 17 years (mean 68.5%; from 20.2 degrees to 6.2 degrees; p = 0.016). Conclusion: We achieved scoliosis correction in line with the international publications. Nearly the same correction efficiency was observed between different age groups of patients in the coronal plane. However, vertebral rotation can be derotated more effectively before the age of 17 years. Orv Hetil. 2021; 162(39): 1573–1578.

Hybrid versus Total Sublaminar Wires in Patients With Spinal Muscular Atrophy Undergoing Scoliosis Surgery

BackgroundEarly versions of spinal muscular atrophy (SMA) scoliosis correction surgeries often involved sublaminar devices. Recently the utilization of pedicle screw is gaining much popularity. Pedicle screw generally believed to provide additional deformity correction, but pedicle size and rotational deformity limit the application of pedicle screw in the thoracic spine, resulting in a hybrid construct of the pedicle screw and sublaminar wire. Studies of the efficacy of hybrid instrumentation in SMA scoliosis is often limited by the scarcity of the disease itself. In this study, we aimed to compare the surgical outcome of using hybrid constructs of the pedicle screw and sublaminar wire and that of sublaminar wire alone in patients with SMA scoliosis.MethodsWe retrospectively reviewed the clinical records and radiographic assessments of patients with SMA scoliosis who underwent corrective surgery between 1993 and 2015. The radiographic assessments included the deformity correction and the progressive change of major curve angle, pelvic tilt (PT) and coronal balance (CB). The correction of deformities was observed postoperatively and at the patient’s 2-year follow-up to test the efficacy of each type of constructs.ResultsThirty-three patients were included in this study. There were 14 and 19 patients in the wiring and the hybrid construct groups, respectively. The hybrid construct demonstrated a higher major curve angle correction (50.5° ± 11.2° vs. 36.4° ± 8.4°, p < 0.001), a higher apical vertebral rotation correction (10.6° ± 3.9° vs. 4.8° ± 2.6°, p < 0.001), and reduced the progression of major curve angle after the 2-year follow-up (5.1° ± 2.9° vs. 8.7° ± 4.8°, p < 0.001). A moderate correlation was observed between the magnitude of correction of apical vertebral rotation angle and major curve (r = 0.528, p = 0.002).ConclusionThis study demonstrated that hybrid instrumentation can provide a greater magnitude of correction in major curve and apical rotation, as well as less major curve progression in comparison with sublaminar wire in patients with SMA scoliosis.Level of evidence III

Concave or convex rod translation first in adolescent idiopathic scoliosis instrumentation with differential rod contouring?

The objective was to assess deformity correction and bone-screw force associated respectively with concave manipulation first, convex manipulation first, and different differential rod contouring configurations. Instrumentation scenarios were computationally simulated for 10 AIS cases with mean thoracic Cobb angle (MT) of 54±8°, apical vertebral rotation (AVR) of 19±2° and thoracic kyphosis of 21±9°. Instrumentations with major correction maneuvers using the concave side rod were first simulated; instrumentations with major correction maneuvers using the convex side rod were then simulated. Simulated correction maneuvers were concave/convex rod translation followed by apical vertebral derotation and then convex/concave rod translation. There were no significant differences in deformity corrections and bone-screw forces between concave rod translation first and convex rod translation first with differential rod contouring. Increasing differential rod contouring angle and concave rod diameter improved AVR correction and increased the TK and bone-screw forces; the effect on the MT Cobb angle was not clinically significant.

Influence of Chêneau-Brace Therapy on Lumbar and Thoracic Spine and Its Interdependency with Cervical Spine Alignment in Patients with Adolescent Idiopathic Scoliosis (AIS)

Chêneau-brace is an effective therapy tool for treatment in adolescent idiopathic scoliosis (AIS). Data on potential interdependent changes of the sagittal profile including the cervical spine are still sparse. The purpose of this study was to evaluate in-brace changes of the thoracic and lumbar spine and their influence on the pelvis and the cervical spine and apical vertebral rotation was reported. Ninety-three patients with AIS undergoing Chêneau-bracing were included. Patients were stratified by lumbar, thoracic and global spine alignment into normolordotic vs. hyperlordotic or normokyphotic vs. hypokyphotic or anteriorly aligned vs. posteriorly aligned groups. The coronal Cobb angle was significantly decreased in all groups indicating good correction while in-brace therapy. Sagittally, in-brace treatment led to significant flattening of lumbar lordosis (LL) in all stratified groups. Thoracic kyphosis (TK) was significantly flattened in the normokyphotic group, but no TK changes were noticed in the hypokyphotic group. Pelvic tilt (PT) stayed unchanged during the in-brace therapy. Chêneau-brace showed marginal changes in the lower cervical spine but had no influence on the upper cervical spine. The apical vertebral axis in primary and secondary curves was unchanged during the first radiological follow-up. Results from this study contribute to better understanding of initial spine behavior in sagittal and axial plane in the context of bracing.

Simultaneous translation on two rods improves the correction and apex translocation in adolescent patients with hypokyphotic scoliosis

OBJECTIVE The objectives of this study were to apply the simultaneous translation on two rods (ST2R) maneuver involving rods contoured with a convexity at the desired thoracic kyphosis (TK) apex level and to assess the effects on the ability to support triplanar deformity corrections, including TK apex improvement, in patients with hypokyphotic adolescent idiopathic scoliosis (AIS). METHODS Using retrospective analysis, the authors examined the digital records that included 2- to 4-week, 1-year, and 2-year postoperative radiographic follow-up data of female hypokyphotic (TK < 20°) AIS patients (Lenke type 1–3) treated with ST2R. The authors assessed the corrections of triplanar deformities by examining the main Cobb angle, TK, rib hump, apical vertebral rotation, Scoliosis Research Society 22-item questionnaire scores, and TK apex translocation. In order to better grasp the potential of ST2R, the outcomes were compared with those of a historical matched case-control cohort treated with a standard rod rotation (RR) maneuver. RESULTS Data were analyzed for 25 AIS patients treated with ST2R and 27 patients treated with RR. The ST2R group had significant improvements in the main Cobb angle and TK, reduction in the rib hump size at each time point, and a final correction rate of 72%. ST2R treatment significantly increased the kyphosis apex by an average of 2.2 levels. The correction rate was higher at each time point in the ST2R group than in the RR group. ST2R engendered favorable TK corrections, although the differences were nonsignificant, at 2 years compared with the RR group (p = 0.056). The TK apex location was significantly improved in the ST2R cohort (p < 0.001). At the 1-month follow-up, hypokyphosis was resolved in 92% of the ST2R cohort compared with 30% of the RR cohort. CONCLUSIONS Resolving hypokyphotic AIS remains challenging. The ST2R technique supported significant triplanar corrections, including TK apex translocation and restoration of hypokyphosis in most patients. Comparisons with the RR cohort require caution because of differences in the implant profile. However, ST2R significantly improved the coronal and sagittal corrections. It also allowed for distribution of correctional forces over two rod implants instead of one, which should decrease the risk of screw pullout and rod flattening. It is hoped that the description here of commercially available reducers used with the authors’ surgical technique will encourage other clinicians to consider using the ST2R technique.

Risk Factors of Unintended Return to the Operating Room in Adult Spinal Deformity

Background To evaluate the incidence and risk factors associated with unintended return to the operating room in adult spinal deformity after spinal deformity corrective surgery. Methods Retrospect of 141 adult spinal deformity patients in a single institution between January 2017 to December 2019. Inclusion criteria enrolled 18 to 80 years old patients who diagnosed congenital/idiopathic/syndromic/acquired spinal deformity underwent posterior corrective spinal surgery. The surgical details and complications were recorded. The rate of unintended return to the operating room (UIROR) during hospitalization was examined, and the risk factors of unintended return to the operating room were investigated via multivariate analysis. Results This is a retrospective study. One hundred and forty-one patients underwent spinal deformity surgery with a mean age of 31.8 years (range 18–69 years) were studied. The rate of unintended return to the operating room was 10.64% (15/141). Two of 15 patients had twice unintended surgery during hospitalization (13.33%). The most principal complication was neurologic deficit (73.3%), Six of 15 postoperative present implants deviation causes severe lower limbs radiating pain (40%). The multivariate analysis shows higher apical vertebral rotation (AVR > grade Ⅱ, odds ratio [OR] = 9.534; 95% CI = 1.983–45.839; P = .005), obesity (OR = 11.776; 95% CI = 1.400-98.851; P = .023), and previous neurological symptom (OR = 7.748; 95% CI = 2.051–29.277; P = .003) were independent predictors of unintended return to the operating room. Conclusion Postoperative neurologic deficit and short-term implant malposition are essential causes of unintended return to the operating room in adult spinal deformity patients. Preoperative factors such as higher AVR (> Grade Ⅱ), obesity, and previous neurological symptom may significantly increase the risk of morbidity in UIROR. Spine surgeons should be alert to these risk factors and require adequate preoperative evaluations to reduce the incidence of unintended return to the operating room.

Vertebral Coplanar Alignment Technique Versus Bilateral Apical Vertebral Derotation Technique in Neuromuscular Scoliosis

Study Design: Single-center retrospective analysis of prospectively collected data. Objective: Our aim was to compare the correction capacity in 3 planes of the VCA technique versus the AD technique in neuromuscular scoliosis patients. Methods: We analized patients with neuromuscular scoliosis that underwent posterior spinal fusion from 2013 to 2017 using 2 different techniques for correction: vertebral coplanar alignment (VCA) that takes into consideration the fact that the medial cortex is more resistant than the lateral cortex, with more anchor points for better distribution of forces and ligamentotaxis and the more widely spread apical derotation (AD) technique. Clinical, surgical, and radiographic information of patients operated on with the AD technique were compared to those operated on with the VCA technique in the coronal, sagittal and axial plane at pre-op, immediate post-op, and 2 year follow-up. Results: 64 patients met inclusion criteria, 34 patients underwent the VCA technique and 30 patients underwent the AD technique. The 2 cohorts did not differ in terms of demographics, clinical presentation or preoperative alignment. There were no significant differences in the correction ability between both techniques regarding curve magnitude, apical vertebral rotation, or pelvic obliquity. There was a significant decrease in thoracic kyphosis in the AD group compared to the VCA group in the immediate postop period (4.2 ± 26.6º for VCA and 13.2 ± 21.3º for AD (p = 0.048)). Conclusion: Both apical derotation technique and vertebral coplanar alignment allow for correction in the 3 planes for patients with neuromuscular scoliosis. VCA is a less hypokyphosing technique than AD.

Pelvic rotation parameters related to in-brace correction in patients with idiopathic scoliosis

Background To identify the pelvic parameters affecting in-brace correction (IBC) in patients with idiopathic scoliosis (IS). Methods Patients with IS receiving Chêneau brace treatment in our scoliosis center from January 2019 to November 2019 were retrospectively analyzed. Pelvic rotation parameters, including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L/R ratio, were collected. Other radiographic data, such as Risser sign, coronal and sagittal balance, curve location, kyphosis, lordosis of each patient were also recorded to analyze their correlations with IBC. Correlation analyses were performed to identify the classified variables influencing IBC. The principal component analysis was used to extract common factors of radiographic parameters to eliminate interaction effects. The linear regression equation was established using principal components, the variables influencing IBC were identified. Results A cohort of 44 patients with IS (36 girls and 8 boys) were included in the present study. The mean IBC was 49.87% (range, 3%–100%). IBC of lumbar IS was negatively correlated with apical rotate factor (ARF, B = –0.385), mainly consisted of pelvic coronal plane rotation (PCPR, 0.449), Cobb angle (CA, 0.575), apical vertebral rotation (AVR, 0.918), and pelvic rotate factor (PRF, B = –0.387), mainly consisted of PT (0.861), PI (0.728), PCPR (–0.570). The regression equation of lumbar IS had statistical significance (F = 6.500, P = 0.005, R2 = 0.317), whereas statistically significance was not found in the regression equation of thoracic IS (F = 2.913, P = 0.106). The remaining parameters were not related to IBC. Conclusions For lumbar IS, ARF and PRF have negative effects on IBC, coronal and sagittal rotation of the pelvis is related to IBC.

Pelvic Rotation Parameters Related to In-Brace Correction in Patients with Idiopathic Scoliosis

BACKGROUND: To identify the pelvic parameters affecting in-brace correction (IBC) in patients with idiopathic scoliosis (IS). METHODS: Patients with IS receiving Chêneau brace treatment in our scoliosis center from January 2019 to November 2019 were retrospectively analyzed. Pelvic rotation parameters, including Pelvic incidence (PI), Sacral slope (SS), pelvic tilt (PT), L/R ratio, were collected. Other radiographic data, such as Risser sign, coronal and sagittal balance, curve location, kyphosis, lordosis of each patient was also recorded to analyze their correlations with IBC. Correlation analyses were performed to identify the classified variables influencing IBC. The principal component analysis was used to extract common factors of radiographic parameters to eliminate interaction effects. The linear regression equation was established using principal components, the variables influencing IBC were identified.RESULTS: A cohort of 44 patients with IS (36 girls and 8 boys) were included in the present study. The mean IBC was 49.87% (range, 3%∽100%). IBC of lumbar IS was negatively correlated with apical rotate factor (ARF, B=-0.385), mainly consisted of pelvic coronal plane rotation (PCPR, 0.449), cobb angle (CA,0.575), apical vertebral rotation (AVR, 0.918), and pelvic rotate factor (PRF, B=-0.387), mainly consisted of PT (0.861), PI (0.728), PCPR (-0.570). The regression equation of lumbar IS had statistical significance (F=6.500, P=0.005，R2=0.317). Whereas statistically significance was not found in the regression equation of thoracic IS (F=2.913, P=0.106). The remaining parameters were not related to IBC.CONCLUSIONS: For lumbar IS, ARF and PRF have negative effects on IBC, Coronal and sagittal rotation of the pelvis is related to IBC.