Thoracic Adolescent Idiopathic Scoliosis Research Articles

Pulmonary Function at Minimum 10 Years After Segmental Pedicle Screw Instrumentation for Thoracic Adolescent Idiopathic Scoliosis.

A prospective multi-center cohort study. This study evaluates the 10-year pulmonary function outcomes for patients with structural thoracic adolescent idiopathic scoliosis (Lenke curve types 1-4, 6) after segmental pedicle screw instrumentation. Adolescent idiopathic scoliosis with thoracic curves is associated with reduced pulmonary function preoperatively. It remains unclear how much pulmonary improvement can be obtained using pedicle screw instrumentation at long-term follow-up. Out of 64 consecutively surgically treated patients with thoracic AIS (Lenke 1-4, 6) using pedicle screw instrumentation, 50 (mean age at final FU 14.7 ± 1.9, 44 females) participated in a prospective 10-year follow-up study. They were evaluated using clinical examination, spinal radiographs, and spirometry preoperatively and at 10-year follow-up. The preoperative percentage predicted values were adjusted for the height loss caused by the scoliosis according to curve size. Preoperatively 49% (20/41) had forced vital capacity (FVC) or forced expiratory volume in one second (FEV1) below 80% of the predicted normal values representing pulmonary function impairment. Major curve correction averaged 76% (SD 9%). FVC improved from preoperative 3.29 L (SD 0.78L) to 3.87 L (0.79L) at 10-year follow-up (P<0.001). This improvement averaged 510mL (SD 560mL) in patients having both preoperative and 10-year follow-up measurements available. The percentage predicted values for FVC showed an improvement from 83% preoperatively to 86% at 10-year follow-up (P=0.048). At 10-year follow-up 38% (19/50) of the patients had FVC or FEV1 below 80% of the predicted values. FVC improved by a mean of 510ml from preoperative to 10-year follow-up in patients undergoing pedicle screw instrumentation for thoracic AIS. Despite 76% scoliosis correction and significant improvement of absolute lung volume values, more than one-third of these surgically treated otherwise healthy young adults fulfilled the criteria for pulmonary function impairment at 10-year follow-up. II.

Does the addition of convex uniplanar screws in hybrid constructs improve 3D surgical correction in thoracic adolescent idiopathic scoliosis posterior fusion?

Hybrid techniques using thoracic sublaminar bands have proved their efficacy in adolescent idiopathic scoliosis posterior fusion, but clinical axial correction sometimes remained disappointing. One solution found was "the frame technique" and the second alternative was the replacement of the convex sublaminar bands by periapical uniplanar screws. The goal of this study was to compare clinical and radiological outcomes of both techniques in a consecutive cohort of adolescent idiopathic scoliosis patients. All patients undergoing primary posterior fusion for thoracic adolescent idiopathic scoliosis between January 2017 and March 2020 were included. Two groups were compared: Group 1 with thoracic sublaminar bands only and Group 2 with periapical uniplanar screws. All patients underwent standing stereoradiographs. The main frontal, sagittal, and axial (apical vertebra rotation) radiological parameters of interest were analyzed. Functional outcomes were assessed using the Scoliosis Research Society 30 score. A total of 147 adolescents were included (Group 1, n = 73 and Group 2, n = 74 patients). In the frontal plane, a greater reduction index was observed in Group 2 (68% versus 62%, p < 0.001) as well as a better apical axial correction (67.8% versus 46.6%, p = 0.03). The number of thoracoplasty performed was reduced (6.7% versus 20.5%, p = 0.02) in Group 2, with a significant decrease in the rate of mechanical complication. No significant loss of correction was observed during follow-up in any of the group. The adjunction of convex uniplanar screws at the periapical levels improved the three-dimensional surgical correction of thoracic adolescent idiopathic scoliosis treated with hybrid constructs. level III, retrospective comparative study.

Pedicle Dysplasia in Proximal Thoracic Adolescent Idiopathic Scoliosis Curves: What are We Missing and What are its Possible Surgical Implications? An Observational Retrospective Study on 104 Patients.

Retrospective cohort study. To assess if pedicle dysplasia is present in proximal thoracic (PT), both structural and nonstructural, compared to main thoracic (MT) curves; and to assess if it is predictive of radiographic outcomes at minimum 2years of follow-up. A retrospective review of surgically-treated Adolescent Idiopathic Scoliosis (AIS) patients with Lenke 1-2-3-4 curves was performed. On preoperative CT-scan, at the apical vertebra, pedicle width on the concavity (PWc) and on the convexity (PWv) and Pedicle Dysplasia Index (PDI, defined as PWc/PWv) were measured. Preoperative and last follow-up (at least 2years) x-rays were reviewed. 104 patients meeting the inclusion criteria were divided into Structural-PT (S-PT) and Nonstructural-PT (NS-PT) groups based on Lenke criteria. PWc (P < .001). And PDI (P < .001 for S-PT, P = .004 for NS-PT) were significantly smaller in the PT than in MT curves for both groups. PT-PWc significantly correlated with follow-up PT Cobb for both groups (P < .001 and P = .015 respectively). PT-PDI significantly correlated with follow-up PT-Cobb (P < .001), CA (P < .040) and T1 tilt (P < .002), only for NS-PT group. NS-PT patients with PWc PT <1mm had higher RSHD (P = .021) and T1 tilt (P = .025) at follow-up. NS-PT patients with PDI PT <.3 had higher RSHD (P < .001), CA (P = .002) and T1 tilt (P = .003) at follow-up. S-PT and NS-PT curves show significant pedicle dysplasia on the concavity. Pedicle dysplasia significantly correlated with shoulder balance at follow-up, for NS-PT patterns. Patients with a PWc <1mm or PDI <.30 are at particular risk of postoperative shoulder imbalance.

Usefulness of the spectral shaping dual-source computed tomography imaging technique in posterior corrective fusion for adolescent idiopathic scoliosis.

Since childhood exposure to radiation has been demonstrated to increase cancer risk with increase in radiation dose, reduced radiation exposure during computed tomography (CT) evaluation is desired for adolescent idiopathic scoliosis (AIS). Therefore, this retrospective study aimed to investigate the radiation dose of dual-source CT using a spectral shaping technique and the accuracy of the thoracic pedicle screw (TPS) placement for posterior spinal fusion (PSF) in patients with AIS. Fifty-nine female patients with thoracic AIS who underwent PSF using CT-guided TPSs were included and divided into two groups comprised of 23 patients who underwent dual-source CT (DSCT) with a tin filter (DSCT group) and 36 who underwent conventional multislice CT (MSCT group). We assessed the CT radiation dose using the CT dose index (CTDIvol), effective dose (ED), and accuracy of TPS insertion according to the established Neo's classification. The DSCT and MSCT groups differed significantly (p < 0.001) in the mean CTDIvol (0.76 vs. 3.31mGy, respectively) and ED (0.77 vs. 3.47mSv, respectively). Although the correction rate of the main thoracic curve in the DSCT group was lower (65.7% vs. 71.2%) (p = 0.0126), the TPS accuracy (Grades 0-1) was similar in both groups (381 screws [88.8%] vs. 600 screws [88.4%], respectively) (p = 0.8133). No patient required replacement of malpositioned screws. Spectral shaping DSCT with a tube-based tin filter allowed a 75% radiation dose reduction while achieving TPS insertion accuracy similar to procedures based on conventional CT without spectral shaping.

Characteristics of back pain in patients with adolescent idiopathic scoliosis: Considerations in candidates for corrective surgery

BackgroundPrevious studies have demonstrated that the point prevalence of back pain ranges from 12% to 33% and that the lifetime prevalence of back pain ranges from 28% to 51% in adolescents. However, few studies on back pain in patients with Adolescent idiopathic scoliosis (AIS) have been conducted, and these studies had significant limitations, including a lack of comparative controls and detailed information about scoliotic deformity or pain location. This study aimed to determine whether adolescents with AIS experience back pain in specific regions. MethodsThis retrospective case-control study included 189 female adolescents with AIS who underwent corrective fusion from 2008–2020. Questionnaires on back pain and health-related quality of life (HRQOL) using the Scoliosis Research Society Outcomes Instrument-22 (SRS-22) were conducted preoperatively. The control group included 2,909 general female adolescents. ResultsThe mean Cobb angles in the main thoracic and thoracolumbar/lumbar curves were 51.4±15.3° and 40.4±12.9°. Back pain characteristics included higher point prevalence (25.9%) and lifetime prevalence (64.6%) compared to healthy controls. Adolescents with back pain showed lower scores in the pain and mental health domains of the SRS-22. Adolescents with major thoracic AIS showed more back pain in the upper and middle right back compared to adolescents with major thoracolumbar/lumbar AIS. ConclusionThe point and lifetime prevalence of back pain were definitely higher in patients with AIS, which affected their HRQOL. There was a relationship between pain around the right scapula and the right major thoracic curve with a rib hump deformity.

Vertebral bone quality score as a novel predictor of proximal junctional kyphosis after thoracic adolescent idiopathic scoliosis surgery.

Proximal junctional kyphosis (PJK) is one of the most common complications after thoracic AIS surgery. Previous studies reported that the etiology of PJK was associated with osteopenia and meanwhile the AIS patients were found osteopenia which could persist into adulthood. Recently, an MRI-based vertebral bone quality score (VBQ) was reported to be a promising tool which can assess preoperative bone quality. This study aims to evaluate the utility of VBQ score in predicting PJK after corrective surgery for thoracic AIS (Lenke 1 and 2). We conducted a retrospective study to identify the predictive efficiency of VBQ score for PJK in thoracic AIS patients. Demographic, radiographic parameters, and surgical variables were collected. VBQ score was calculated using preoperative T1-weighted MRI. Univariate analysis, linear regression, and multivariate logistic regression were performed to determine potential risk factors of PJK and correlation between other parameters and VBQ score. Receiver operating characteristic analysis and area under the curve values were utilized to evaluate the predictive efficiency of VBQ score for PJK. A total of 206 patients (aged 14.4 ± 2.3years) were included, of which 33 (16.0%) developed PJK. VBQ scores were significantly different between the PJK and non-PJK groups (2.8 ± 0.2 vs 2.5 ± 0.2, P < 0.01). A significant positive correlation was found between VBQ score and PJA (R2 = 0.1728, P < 0.01).On multivariate analysis, VBQ score was the only significant predictor of PJK (odds ratio = 2.178, 95% CI = 1.644-2.885, P < 0.001), with a predictive accuracy of 83%. Higher VBQ scores were independently associated with PJK occurrence after corrective surgery for thoracic AIS. Preoperative measurement of VBQ score on MRI may serve as a valuable tool in planning thoracic AIS surgery.

The three-dimensional coupling mechanism in scoliosis and its consequences for correction

IntroductionIn idiopathic scoliosis, the anterior spinal column has rotated away from the midline and has become longer through unloading and expansion of the intervertebral discs. Theoretically, extension of the spine in the sagittal plane should provide room for this longer anterior spinal column, allowing it to swing back towards the midline in the coronal and axial plane, thus reducing both the Cobb angle and the apical vertebral rotation.MethodsIn this prospective experimental study, ten patients with primary thoracic adolescent idiopathic scoliosis (AIS) underwent MRI (BoneMRI and cVISTA sequences) in supine as well as in an extended position by placing a broad bolster, supporting both hemi-thoraces, under the scoliotic apex. Differences in T4–T12 kyphosis angle, coronal Cobb angle, vertebral rotation, as well as shape of the intervertebral disc and shape and position of the nucleus pulposus, were analysed and compared between the two positions.ResultsExtension reduced T4–T12 thoracic kyphosis by 10° (p < 0.001), the coronal Cobb angle decreased by 9° (p < 0.001) and vertebral rotation by 4° (p = 0.036). The coronal wedge shape of the disc significantly normalized and the wedged and lateralized nucleus pulposus partially reduced to a more symmetrical position.ConclusionSimple extension of the scoliotic spine leads to a reduction of the deformity in the coronal and axial plane. The shape of the disc normalizes and the eccentric nucleus pulposus partially moves back to the midline.

Associated factors and effects of coronal vertebral wedging angle in thoracic adolescent idiopathic scoliosis

BackgroundAdolescent idiopathic scoliosis (AIS) causes vertebral wedging, but associated factors and the impact of vertebral wedging are still unknown. We investigated associated factors and effects of vertebral wedging in AIS using computed tomography (CT). MethodsPreoperative patients (n = 245) with Lenke types-1 and 2 were included. Vertebral wedging, lordosis, and rotation of the apical vertebra were measured by preoperative CT. Skeletal maturity and radiographic global alignment parameters were evaluated. Multiple regression analysis was performed on associated factors for vertebral wedging. Side-bending radiographs were evaluated using multiple regression analysis to calculate the percentage of reduction of Cobb angles to determine curve flexibility. ResultsThe mean vertebral wedging angle was 6.8 ± 3.1°. Vertebral wedging angle was positively correlated with proximal thoracic (r = 0.40), main thoracic (r = 0.54), and thoracolumbar/lumbar curves (r = 0.38). By multiple regression, the central sacral vertical line (p = 0.039), sagittal vertical axis (p = 0.049), main thoracic curve (p = 0.008), and thoracolumbar/lumbar curve (p = 0.001) were significant factors for vertebral wedging. In traction and side-bending radiographs there were positive correlations between curve rigidity and the vertebral wedging angle (r = 0.60, r = 0.59, respectively). By multiple regression, thoracic kyphosis (p < 0.001), lumbar lordosis (p = 0.013), sacral slope (p = 0.006), vertebral wedging angle (p = 0.003), and vertebral rotation (p = 0.002) were significant factors for curve flexibility. ConclusionsVertebral wedging angle was found to be highly correlated to coronal Cobb angle, with larger vertebral wedging indicating less flexibility.

Influence of posterior instrumented correction with pedicle screw dual rod systems on thoracic kyphosis in Lenke 1 and 2 curves: minimum 2years follow-up.

Adolescent idiopathic scoliosis (AIS) often correspond with hypo thoracic kyphosis (TK) or even lordosis. The aim of this study was to analyze the influence of posterior instrumentation in thoracic AIS. Analysis of prospectively collected AIS-data with structural thoracic curves (Lenke type 1 & 2), operated 2010-2019 with pedicle screw dual rod systems in one scoliosis center. Follow-up (FU) minimum 24months. Coronal and sagittal angles measured based on standing long-cassette-X-rays: thoracic major (MC), proximal thoracic (PC) and lumbar curve (LC), TK, lumbar lordosis (LL). values as mean ± SD, differences by student's t-test (significancy a = 0.05), Pearson's correlation, sub-analysis with sagittal modifier (-, N, +). A total of 127 AIS could be identified (63% type 1, 37% type 2). Mean FU 32.2 ± 16.6months, mean age 14 ± 1.5years. Mean Correction of MC 73 ± 12%, PC 51 ± 17%, LC 69 ± 21% with a significantly better correction of PC in Lenke 2 curves(p < 0.05). On average, TK (FU-preop) decreased by -2.1 ± 12.1°(p < 0.05) in all AIS. Whereas TK in type 1 was unchanged (p = 0.9), TK significantly decreased by - 6.0 ± 12.7°(p < 0.05) in type 2. No significant difference in LL. TK in hypokyphotic cases increased by 9.5 ± 5.5°(p < 0.05), stayed almost unchanged (- 1.4 ± 9.1°,p = 0.2) in normokyphotic, decreased by - 17.2 ± 14.2°(p < 0.05) in hyperkyphotic cases. Only hypokyphotic cases had a moderately strong correlation between correction of LC (r = 0.6) and PC (r = - 0.4) (frontal plane) and change from pre- to postoperative TK (sagittal plane) (r = 0.6). No relevant correlations for normo- and hyperkyphotic AIS. Postoperative hypokyphosis was significantly more often in Lenke 2 (16.3% vs. 2.6%, p < 0.05). Rod diameter (5,5mm versus 6mm) had no significant influence. Significant correction of hypo- and hyperkyphosis can be achieved with posterior spinal fusion (pedicle screw dual rod systems), whereas normokyphotic spines stay unchanged. However, Lenke 2 curves have a significantly higher risk for a postoperative thoracic hypokyphosis.

Pedicle morphometry analysis of main thoracic apex adolescent idiopathic scoliosis

IntroductionScrew insertion during scoliosis surgery uses free-hand pedicle screw insertion methods. However, there is a wide variation in pedicle shapes, sizes, and morphometry, especially in scoliosis patients. CT scan pedicle measurements in main thoracic Lenke type 1 adolescent idiopathic scoliosis can help visualize this diversity. This study aimed to highlight the features of pedicle morphometry on the concave and convex sides, including pedicle diameter (width in axial and height in the sagittal plane), the depth to the anterior cortex, and Watanabe Pedicle classification in patients with main thoracic apex adolescent idiopathic scoliosis.Materials and methodsThis study was a cross-sectional observational study of Adolescent Idiopathic Scoliosis (AIS) patients whose apex in the main thoracic patient underwent deformity correction procedures. We used a three-dimensional CT scan to evaluate pedicle morphometry on the apex vertebrae, three consecutive vertebrae above and below the apex.ResultsA total of 6 patients with apex main thoracic AIS with 84 pedicles consisting of 42 pedicles from each concave and convex curve were analyzed. All of the samples were female, with the mean age at the procedure being 21.2 ± 5.56. The mean cobb angle was 62° ± 23°, with the main apex between VT8-VT10. The size of the pedicle was bigger from upper to lower vertebrae. The mean pedicle depth, pedicle width, and pedicle height for the concave side were 36.06 ± 4.31 mm, 3.91 ± 0.66 mm, and 9.16 ± 1.52 mm, respectively. Meanwhile, the convex side is 37.52 ± 1.84 mm, 5.20 ± 0.55 mm, and 11.05 ± 0.70 mm, respectively. We found a significant difference between the concave and convex sides for the pedicle width and height. The concave and convex sides were mainly classified as type C (38%) and type A (50%) Watanabe pedicle.ConclusionPedicle width and pedicle height are significantly different between the concave and the convex side with convex side has better Watanabe pedicle classification. Pre-operative CT evaluation is essential for planning proper pedicle screw placement in AIS patients.

Increased risk of thoracic hypokyphosis after posterior spinal correction and fusion in adolescent idiopathic scoliosis with thoracic double curve

Adolescent idiopathic scoliosis (AIS) is often associated with thoracic hypokyphosis or even lordosis. To analyze the influence of posterior correction and fusion in thoracic, structurally double-curved AIS. Out of 127 thoracic AIS (Lenke types1 and2) recorded prospectively, idiopathic double thoracic curve AIS were analyzed retrospectively. Surgery 2010-2019 with pedicle screw double rod systems in ascoliosis center. Follow-up (FU) at least 2years. Frontal and sagittal angles (whole-spine radiographs, 2planes): thoracic curve (MK), proximal-thoracic curve (PK) and lumbar curve (LK), thoracic kyphosis (TK), lumbar lordosis (LL). values as MW ± SD, students t‑test (significance a = 0.05), Pearson's correlation, sub-analysis with sagittal modifiers (-, N, +). Atotal of 47AIS-double thoracic curve were identified, mean FU 29.3 ± 12.2months, mean age 14 ± 1.5years. The mean correction (FU-preop) of MK was 67%, PK 53%, LK 73%, each significant, (p < 0.05). On average, TK (FU-preop) decreased by -6.5 ± 11.6° (p < 0.05), no significant change from FU (p = 0.6). TK (FU-preop) increased by 8.6 ± 5.0° (p < 0.05) in hypokyphotic cases, significantly decreased by -4.8 ± 9.6° in normokyphotic AIS and -25.3 ± 11.1° in hyperkyphotic cases, respectively (p < 0.05). In hypokyphosis: moderately strong correlation between correction PK (r = -0.5) and spontaneous correction LK (r = 0.8) (frontal plane) and change from pre- to postop TK (sagittal plane) (p < 0.05). Moderate correlation for hyperkyphosis: correction PK (r = -0.5) and postop TK (p < 0.05). No relevant correlations for normokyphosis. 17% had postop hypokyphosis, of which 0% had preop hypokyphosis. Rod diameter (5.5 mm vs. 6 mm) had no significant effect on TC. Posterior instrumented correction and fusion (pedicle screw dual rod systems) can significantly correct both lateral curves in idiopathic double thoracic curves, although it is associated with an increased risk of postop thoracic hypokyphosis, especially in preoperatively normokyphotic patients.

Accuracy of thoracic pedicle screw placement in adolescent idiopathic scoliosis patients using the entry point identified by new landmarks: a computed tomography study

BackgroundAlthough thoracic pedicle (TP) screw has gained increasingly popularity in the surgical treatment of adolescent idiopathic scoliosis (AIS) patients, questions remain about the accurate selection of entry point for TP screw placement in these patient. The main objective of the present study was to evaluate the accuracy of TP screw placement in AIS patients using the entry point identified by new landmarks.MethodsThirty-four thoracic AIS patients treated with posterior TP screw instrumentation were included. All these TP screws were inserted through the entry point identified by new landmarks with free-hand technique. Postoperative CT scans were obtained to evaluate the screw position. The perforations of the pedicle were classified as grade 0 (no perforation), grade 1 (≤ 2 mm), grade 2 (2.1–4 mm), grade 3 (4.1–6 mm) and grade 4 (6.1–8.0 mm). Screws in grade 0, displaced either medially or anteriorly in grade 1 and displaced laterally in grades 1 to 2 were considered acceptable.ResultsOf the 495 TP screws inserted, 34 (6.9%) screws were displaced with 7 screws (1.4%) displaced medially, 20 screws (4.1%) displaced laterally and 7 screws (1.4%) displaced anteriorly (P < 0.05). Among the 34 displaced screws, 11 screws (32.4%) were considered as grade 1, 14 screws (38.2%) as grade 2 and 9 screws (29.4%) as grade 3 (P < 0.05). The overall rate of acceptable screws was 97.8%. No screw-related complication was noted.ConclusionOur new method for selecting the entry point of TP screw in AIS patients is convenient and can achieve high accuracy of screw placement, which is worthy of being widely popularized.

Benefit-risks analysis of thoracoplasty in adolescent idiopathic scoliosis treated by sublaminar bands

IntroductionCosmetic concerns are one of the main complaints of patients with adolescent idiopathic scoliosis (AIS). Several studies have shown a significant improvement in self-image scores after thoracoplasty. However, the effects of thoracoplasty on pulmonary function and clinical outcomes remain debated. The objective was to analyze the benefits and risks of thoracoplasty during AIS surgery using a hybrid construct with sublaminar bands. Material and methodsIn this monocentric prospective cohort study, 68 patients with thoracic AIS were consecutively included between 2016 and 2017. All patients had low-dose 3D radiographs. Surgical correction was performed via the posterior approach, using the posteromedial translation technique with a hybrid construct (thoracic sublaminar band and lumbar pedicle screws). A thoracoplasty was proposed in cases of severe rib hump (more than 3cm). Pulmonary function was assessed by pulmonary function tests (PFT) with forced vital capacity, forced expiratory volume in 1 second and total lung capacity). Radiographic parameters and PFT were compared between patients who had or had not had a thoracoplasty preoperatively and 2 years postoperatively. The SRS-22 score was collected at follow-up. ResultsThe average age was 15±3 years. Nineteen patients (27%) had a thoracoplasty. The demographic, radiographic and respiratory data of the 2 groups were comparable preoperatively. The correction was similar between the groups on sagittal and coronal views. At 2 years, the PFTs were comparable to those performed preoperatively and no difference was found between the groups. None of the 12 patients who had a pleural effusion had it drained. The total SRS-22 score and the cosmetic subscore were higher in the thoracoplasty group (p<0.03). DiscussionThe association of a thoracoplasty with AIS surgery improves the self-image of patients without altering the PFTs at 2 years postoperatively. Given the low morbidity of thoracoplasty, it seems reasonable to offer it to patients with severe rib hump and high cosmetic demands. Level of evidenceIII.

Systematic Review and Meta-analysis: Does Anterior-Posterior Spinal Fusion Still have a Role in Severe Thoracic Adolescent Idiopathic Scoliosis?

Debate exists as to whether anterior-posterior spinal fusion (APSF), rather than posterior-only spinal fusion (PSF), provides benefit for treating severe thoracic adolescent idiopathic scoliosis (AIS). This systematic review and meta-analysis compare (1) Cobb angle correction, (2) complication and reoperation rate, (3) pulmonary function, (4) number of fused segments, and 5) patient-reported outcome measures (PROMs) in both groups. Electronic databases were searched to identify studies that met the following inclusion criteria: comparative studies (level 3 or above), severe thoracic curves (≥ 70°), age ≤ 16, AIS aetiology, Lenke 1-4 curves and follow-up ≥ 1year for ≥ 95% of patient population. Literature was graded for quality and bias using GRADE and MINORS criteria. Eight studies were included, defined by GRADE as low or moderate level evidence. Three studies showed superior curve correction in the APSF group; however, the meta-analysis showed no significant difference in curve correction between groups (95% CI - 3.45-12.96, P = 0.26). There were more complications in the APSF group, without statistical significance (95% CI 0.53-3.39, P = 0.54; I 2 = 0%, P = 0.78). There were no re-operations in either group. Two studies reported pulmonary function; one showed better function in the APSF group, the other better function in the PSF group. One study showed fewer fused segments in the APSF group, however, no significance was observed in the meta-analysis (95%CI - 1.65-0.31, P = 0.18). Three studies reported PROMs with no differences reported between groups. APSF and PSF have been found to have comparable results. The present evidence cannot support recommendations for guidelines on future practice with regards to effect on curve correction, complications, re-operations, pulmonary function or PROMs. Level III, Systematic review of Level-III studies.

Thoracic posterior spinal instrumented fusion vs. thoracic anterior spinal tethering for adolescent idiopathic scoliosis with a minimum of 2-year follow-up: a cost comparison of index and revision operations.

To compare direct costs of index and revision operations of thoracic posterior spinal instrumented fusion (TPSIF) and thoracic anterior spinal tethering (TAST) for adolescent idiopathic thoracic scoliosis in children. Children (ages 11-18years) who underwent TPSIF and TAST (2/2013-9/2019) were reviewed. Follow-up < 2years and cervical instrumentation and/or instrumentation of a lumbar level at L3 or below were exclusion criteria. Patient demographics, radiographic curve magnitude, index operations and postoperative data, as well as indications for revisions/readmissions were collected. Direct costs were identified and compared for index and revision operations during follow-up. One hundred and four patients were included (TPSIF: 78; TAST: 25). TAST procedures were performed in children significantly younger and for smaller curve magnitudes. They had significantly fewer levels instrumented, shorter operating room (OR) times, and less estimated blood loss (EBL). After operation, a significantly higher percentage of TAST were admitted to ICU. Hospital length of stay (LOS) was similar between groups. Index operations' average direct costs were significantly higher for TAST than TPSIF ($52,947 v. $46,641; p = 0.02). Major cost drivers for both groups were implants, OR services, post-anesthesia care unit (PACU), and room/board. Revisions following TAST were more frequent than for TPSIF (36 v. 11.5%). Majority of TPSIF revisions were for junctional deformity. Curve progression and overcorrection were most common reason for TAST revisions. Average direct costs for revisions/readmissions were similar between groups (TPSIF: $28,485 v. TAST: $27,590; p = 0.46). Index operations' average direct costs were statistically similar between TPSIF and TAST for adolescent idiopathic scoliosis. Major cost drivers were implants, OR services, PACU, and room/board. TAST index operations' direct costs and associated direct costs for implants and room/board were significantly higher, while their anesthesia and OR services were significantly lower than TPSIF. TAST revisions were for overcorrection and curve progression, while TPSIF revisions were most commonly for junctional deformity. Overall average direct costs for revisions were similar despite revision rates being higher for TAST. III.

Convex–concave and anterior–posterior spinal length discrepancies in adolescent idiopathic scoliosis with major right thoracic curves versus matched controls

PurposeThe apical deformation in adolescent idiopathic scoliosis (AIS) is a combination of rotation, coronal deviation and passive anterior lengthening of the spine. In AIS surgery, posterior–concave lengthening or anterior–convex shortening can be part of the corrective maneuver, as determined by the individual surgeon’s technique. The magnitude of convex–concave and anterior–posterior length discrepancies, and how this needs to be modified to restore optimal spinal harmony, remains unknown.MethodsCT-scans of 80 pre-operative AIS patients with right convex primary thoracic curves were sex- and age-matched to 80 healthy controls. The spinal length parameters of the main thoracic curves were compared to corresponding levels in controls. Vertebral body endplates and posterior elements were semi-automatically segmented to determine the length of the concave and convex side of the anterior column and along the posterior pedicle screw entry points while taking the 3D-orientation of each individual vertebra into account.ResultsThe main thoracic curves showed anterior lengthening with a mean anterior–posterior length discrepancy of + 3 ± 6%, compared to a kyphosis of − 6 ± 3% in controls (p < 0.01). In AIS, the convex side was 20 ± 7% longer than concave (0 ± 1% in controls; p < 0.01). The anterior and posterior concavity were 7 and 22 mm shorter, respectively, while the anterior and posterior convexity were 21 and 8 mm longer compared to the controls.ConclusionsIn thoracic AIS, the concave shortening is more excessive than the convex lengthening. To restore spinal harmony, the posterior concavity should be elongated while allowing for some shortening of the posterior convexity.

Assessment of changes in the sagittal plane of the spine in girls with adolescent idiopathic scoliosis using the moire method.

The gold standard in the clinical assessment of the extent of scoliosis is the Cobb method but the analysis also covers the changes that occur within the spine and trunk in relation to the transverse and sagittal planes. The study aimed to estimate changes in the sagittal plane of the spine in girls with right-sided thoracic adolescent idiopathic scoliosis. The study involved 29 girls with scoliosis (13.6 ± 0.6 years) and 36 healthy girls as the comparison group. The tests included an interview, clinical examination (with the use of Adam's test and the Cobb angle), and examination of shape of the spine surface with the use of the photogrammetric method and the projection moire effect. Lower values of the thoracic kyphosis parameters were found in the scoliosis group. Significant differences were noted for the parameters of the lumbosacral section α (p= 0.02), thoracolumbar section β (p< 0.001), the upper thoracic section γ (p< 0.001), thoracolumbar and upper thoracic section β+γ (p< 0.001) and the total size of α+β+γ (p< 0.001) curvatures. The study showed that with an increase in the angular value of the thoracic curvature, the thoracic kyphosis decreased.

The Effects of Adolescent Idiopathic Scoliosis on Axial Rotation of the Spine: A Study of Twisting Using Surface Topography.

Axial twisting of the spine has been previously shown to be affected by scoliosis with decreased motion and asymmetric twisting. Existing methods for evaluating twisting may be cumbersome, unreliable, or require radiation exposure. In this study, we present an automated surface topographic measurement tool to evaluate global axial rotation of the spine, along with two measurements: twisting range of motion (TROM) and twisting asymmetry index (TASI). The aim of this study is to evaluate the impact of scoliosis on axial range of motion. Adolescent idiopathic scoliosis (AIS) patients and asymptomatic controls were scanned in a topographic scanner while twisting maximally to the left and right. TROM was significantly lower for AIS patients compared to control patients (69.1° vs. 78.5°, p = 0.020). TASI was significantly higher for AIS patients compared to control patients (29.6 vs. 19.8, p = 0.023). After stratifying by scoliosis severity, both TROM and TASI were significantly different only between control and severe scoliosis patients (Cobb angle > 40°). AIS patients were then divided by their major curve region (thoracic, thoracolumbar, or lumbar). ANOVA and post hoc tests showed that only TROM is significantly different between thoracic AIS patients and control patients. Thus, we demonstrate that surface topographic scanning can be used to evaluate twisting in AIS patients.

Thoracic kyphosis in light of lumbosacral alignment in thoracic adolescent idiopathic scoliosis: recognition of thoracic hypokyphosis and therapeutic implications

BackgroundThe uniqueness of spinal sagittal alignment in thoracic adolescent idiopathic scoliosis (AIS), for example, the drastically smaller thoracic kyphosis seen in some patients, has been recognized but not yet fully understood. The purpose of this study was to clarify the characteristics of sagittal alignment of thoracic AIS and to determine the contributing factors.MethodsWhole spine radiographs of 83 thoracic AIS patients (73 females) were analyzed. The measured radiographic parameters were the Cobb angle of thoracic scoliosis, thoracic kyphosis (TK), lumbar lordosis (LL), C7 sagittal vertical axis (C7 SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Additionally, max-LL, which was defined as the maximum lordosis angle from the S1 endplate, the inflection point between thoracic kyphosis and lumbar lordosis, and the SVA of the inflection point (IP SVA) were measured. The factors significantly related to a decrease in TK were assessed by stepwise logistic regression analysis. In addition, cluster analysis was performed to classify the global sagittal alignment.ResultsThe significant factors for a decrease in TK were an increase in SS (p = 0.0003, [OR]: 1.16) and a decrease in max-LL (p = 0.0005, [OR]: 0.89). According to the cluster analysis, the global sagittal alignment was categorized into the following three types: Type 1 (low SS, low max-LL, n = 28); Type 2 (high SS, low max-LL, n = 22); and Type 3 (high SS, high max-LL, n = 33).ConclusionsIn thoracic AIS, a decreased TK corresponded to an increased SS or a decreased max-LL. The sagittal alignment of thoracic AIS patients could be classified into three types based on SS and max-LL. One of these three types includes the unique sagittal profile of very small TK.

Preoperative factors associated with optimal outcomes of selective thoracic fusion at 5years.

Prior work identified optimal outcomes at 2years following selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS) but it is unclear whether these published predictors represent what is required to achieve an optimal outcome with further time and potential growth. The purpose of this study was to determine the preoperative factors associated with optimal outcome of STF for AIS at 5years. Patients with primary thoracic AIS (Lenke 1-4C curves) who underwent a STF and had minimum 5years of follow-up were included. Optimal postoperative outcomes for a STF included a deformity-flexibility quotient (DFQ) < 4, lumbar curve < 26°, lumbar correction > 37%, C7-CSVL < 2cm, lumbar prominence < 5°, and trunk shift < 1.5cm. These outcomes were used to determine whether adhering to published recommendations for STF increased the likelihood of obtaining an optimal outcome at 5years, which included: preoperative lumbar curve < 45°, lumbar bend < 25°, apical vertebral translation ratio > 1.2, and thoracic/thoracolumbar Cobb ratio > 1.2. 127 patients met inclusion. A preoperative lumbar curve < 45° was associated with an increased likelihood of achieving three of the optimal outcomes: DFQ < 4, lumbar curve < 26°, and lumbar prominence < 5°. Following the 25° bend rule resulted in two optimal outcomes, while Cobb ratio > 1.2 was only associated with one optimal outcome. AVT > 1.2 was not significantly associated with any optimal outcome measures. This study found that at 5years, performing a STF when there is a preoperative lumbar Cobb < 45° remained the best guideline for increasing the likelihood of an optimal outcome.