Anterior vertebral body tethering shows clinically comparable shoulder balance outcomes to posterior spinal fusion.

PURPOSE: Posterior spinal fusion (PSF) is the current gold standard in surgical treatment for adolescent idiopathic scoliosis. Vertebral body tethering (VBT) is a fusionless alternative. Shoulder balance is an important metric for outcomes and patient satisfaction. Here we compare shoulder balance outcomes between PSF and VBT. METHODS: In this retrospective review, the pre-operative and post-operative absolute radiographic shoulder height (|RSH|) of 45 PSF patients were compared to 46 VBT patients. Mean values were compared and then collapsed into discrete groups (|RSH| GROUP) and compared. Patients were propensity score matched. Regression models based on pretest-posttest designs were used to compare procedure type on post-operative outcomes. RESULTS: Pre-operatively there were no differences in |RSH| between PSF and VBT, however, at latest post-operative follow-up PSF maintained a larger |RSH| imbalance compared to VBT (0.91 cm vs 0.63 cm, p = 0.021). In an ANCOVA regression, PSF was associated with a larger |RSH| imbalance compared to VBT, F(1, 88) = 5.76, p = 0.019. An ordinal logistic regression found that the odds ratio of being in a worse |RSH| GROUP for PSF vs VBT is 2.788 (95% CI = 1.099 to 7.075), a statistically significant effect χ2(1) = 4.658, p = 0.031. Results were similar in subgroup analyses of Lenke 1 and Lenke 2 patients, though to less statistical significance. CONCLUSION: While PSF was found to be associated with worse |RSH| outcomes, the actual numbers (2-3 mm) are unlikely to be clinically meaningful. Thus, in this analysis, VBT can be said to show comparable shoulder balance outcomes to PSF.

Incidence of Tether Breakage in Anterior Vertebral Body Tethering.

BACKGROUND: Thoracic anterior vertebral body tethering (TAVBT) is an emerging treatment for adolescent idiopathic scoliosis. Tether breakage is a known complication of TAVBT with incompletely known incidence. We aim to define the incidence of tether breakage in patients with adolescent idiopathic scoliosis who undergo TAVBT. The incidence of tether breakage in TAVBT is hypothesized to be high and increase with time postoperatively. METHODS: All patients with right-sided, thoracic curves who underwent TAVBT with at least 2 and up to 3 years of radiographic follow-up were included. Tether breakage between 2 vertebrae was defined a priori as any increase in adjacent screw angle >5 degrees from the minimum over the follow-up period. The presence and timing of tether breakage were noted for each patient. A Kaplan-Meier survival analysis was performed to calculate expected tether breakage up to 36 months. χ 2 analysis was performed to examine the relationship between tether breakage and reoperations. Independent t test was used to compare the average final Cobb angle between cohorts. RESULTS: In total, 208 patients from 10 centers were included in our review. Radiographically identified tether breakage occurred in 75 patients (36%). The initial break occurred at or beyond 24 months in 66 patients (88%). Kaplan-Meier survival analysis estimated the cumulative rate of expected tether breakage to be 19% at 24 months, increasing to 50% at 36 months. Twenty-one patients (28%) with a radiographically identified tether breakage went on to require reoperation, with 9 patients (12%) requiring conversion to posterior spinal fusion. Patients with a radiographically identified tether breakage went on to require conversion to posterior spinal fusion more often than those patients without identified tether breakage (12% vs. 2%; P =0.004). The average major coronal curve angle at final follow-up was significantly larger for patients with radiographically identified tether breakage than for those without tether breakage (31 deg±12 deg vs. 26 deg±12 deg; P =0.002). CONCLUSIONS: The incidence of tether breakage in TAVBT is high, and it is expected to occur in 50% of patients by 36 months postoperatively. LEVEL OF EVIDENCE: Level IV.

Bilateral vertebral body tethering: identifying key factors associated with successful outcomes.

PURPOSE: The treatment of operative double major pediatric spinal deformities (e.g., Lenke 3 or 6) with bilateral vertebral body tethering (VBT) can be significantly more challenging when compared to other deformity patterns (e.g., Lenke 1) or treatment with a posterior spinal fusion. We aimed to identify preoperative and perioperative characteristics that were associated with successful postoperative outcomes in patients treated with both a thoracic and thoracolumbar (e.g., bilateral) tether. METHODS: We retrospectively assessed radiographic and clinical data from patients enrolled in a large multi-center study who had a minimum postoperative follow-up of two years. Standard radiographic parameters were extracted from standing spine and left hand-wrist radiographs at various timepoints. We classified patients based on their preoperative deformity pattern (Primary Thoracic [TP] vs. Primary Thoracolumbar [TLP]) and assessed: (1) deformity balance, (2) tilt of the transitional vertebra, and (3) postoperative success. RESULTS: We analyzed data from thirty-six patients (TP: 19 and TLP: 17). We observed no relationship between deformity balance at first erect and postoperative success (p = 0.354). Patients with a horizontal transitional vertebra at first erect were significantly (p = 0.001) more likely to exhibit a successful outcome when compared to those who exhibited a tilted transitional vertebra (83% vs. 62%). Patients who had TLP were also more likely to exhibit a successful outcome when compared to patients who exhibited TP (76% vs. 50%). CONCLUSION: These data indicate that double major deformities can be successfully treated with VBT, particularly for those who exhibit TLP.

Vertebral body tethering for adolescent idiopathic scoliosis: a review.

PURPOSE: Adolescent Idiopathic Scoliosis (AIS) remains the most common type of pediatric scoliosis, mostly affecting children between ages 10 and 18. Vertebral body tethering (VBT) offers a non-fusion alternative to the gold standard spinal fusion that permits flexibility and some growth within instrumented segments. This article will serve as a comprehensive literature review of the current state-of-the-art of VBT in relation to radiographic and clinical outcomes, complications, and the learning curve associated with the procedure. METHODS: A systematic literature review was conducted on PubMed, Scopus, and Web of Science from April 2002 to December 2022. Studies were included if they discussed VBT and consisted of clinical studies in which a minimum 2-years follow-up was reported, and series that included anesthetic considerations, learning curve, and early operative morbidity. RESULTS: Forty-nine studies spanning the period from April 2002 to December 2022 were reviewed. CONCLUSION: This article illustrates the potential benefits and challenges of the surgical treatment of AIS with VBT and can serve as a basis for the further study and refinement of this technique ideally as a living document that will be updated regularly.

Double major curvature treated with vertebral body tethering of both curves: how do outcomes compare to posterior spinal fusion?

PURPOSE: Vertebral body tethering (VBT) is a non-fusion alternative to posterior spinal fusion (PSF). There have been few reports on VBT of two curvatures. We aim to compare the radiographic outcomes between VBT and PSF in patients with double curvatures in which both curves were instrumented. METHODS: 29 AIS patients matched by Lenke, age (± 2 years), triradiate cartilage closure status, major Cobb angle (± 8°), and T5-T12 kyphosis (± 10°). Variables were compared using Wilcoxon rank-sum tests, Student's t tests, and chi-Square. Clinical success was defined as major curve < 35°. RESULTS: Group baseline demographics were similar. Major thoracic (T) curve types had significantly better major (VBT 51.5 ± 7.9° to 31.6 ± 12.0° [40%] vs. PSF 54.3 ± 7.4° to 17.4 ± 6.5° [68%]; p = 0.0002) and secondary curve correction in the PSF group. 71% of major T VBT patients were clinically successful versus 100% of PSF. Major thoracolumbar (TL) curve types experienced comparable major (VBT 52.3 ± 7.0° to 18.3 ± 11.4° (65%) vs. PSF 53.0 ± 5.2° to 23.8 ± 10.9° (56%); p = 0.2397) and secondary curve correction. 92% of major TL VBT patients were clinically successful versus 75% in the PSF group. There was no difference in T5-12 kyphosis or lumbar lordosis between groups for any curve type. There were 4 patients (13.8%) with major complications in the VBT group compared to 0 (0%) in the PSF. CONCLUSION: Patients with double major AIS who underwent VBT with major T curve types had less correction than PSF; however, those with major TL curves experienced similar radiographic outcomes regardless of procedure. Complications were greater for VBT.

Non-Fusion Versus Fusion Surgery in Pediatric Idiopathic Scoliosis: What Trade-Offs in Outcomes Are Acceptable for the Patient and Family?

BACKGROUND: Vertebral body tethering and other non-fusion techniques for the treatment of pediatric idiopathic scoliosis are increasing in popularity. There is limited physician consensus on this topic as the result of a paucity of published data regarding which patients most benefit from non-fusion strategies. Thus, much of the decision-making is left to patients and parents, who must select a treatment based on their goals and values and the information available from health-care providers, the internet, and social media. We sought to understand patient and family preferences regarding the attributes of fusion versus non-fusion surgery that drive these choices. METHODS: Patients and families were recruited from 7 pediatric spine centers and were asked to complete a survey-based choice experiment that had been jointly developed with the U.S. Food and Drug Administration (FDA) to evaluate patient preferences. Choices between experimentally designed alternatives were analyzed to estimate the relative importance of outcomes and requirements associated with the choice options (attributes). The attributes included appearance, confidence in the planned correction, spinal motion, device failure, reoperation, and recovery period. The inclusion criteria were (1) an age of 10 to 21 years and (2) a diagnosis of adolescent idiopathic scoliosis in patients who were considering, or who had already undergone, treatment with fusion or non-fusion surgery. Preference weights were estimated from the expected changes in choice given changes in the attributes. RESULTS: A total of 344 respondents (124 patients, 92 parents, and 128 parent/patient dyads) completed the survey. One hundred and seventy-three patients were enrolled prior to surgery, and 171 were enrolled after surgery. Appearance and motion were found to be the most important drivers of choice. For the entire cohort, fusion was preferred over non-fusion. For patients who were considering surgery, the most important attributes were preservation of spinal motion and appearance. CONCLUSIONS: Patients and families seeking treatment for idiopathic scoliosis value appearance and preservation of spinal motion and, to a lesser extent, reoperation rates when considering fusion versus non-fusion surgery.

Pregnancy and Childbirth After Spinal Fusion for Adolescent Idiopathic Scoliosis.

BACKGROUND: Little data exist on pregnancy and childbirth for adolescent idiopathic scoliosis (AIS) patients treated with a spinal fusion. The current literature relies on data from patients treated with spinal fusion techniques and instrumentation, such as Harrington rods, that are no longer in use. The objective of our study is to understand the effects of spinal fusion in adolescence on pregnancy and childbirth. METHODS: Prospectively collected data of AIS patients undergoing posterior spinal fusion that were enrolled in a multicenter study who have had a pregnancy and childbirth were reviewed. Results were summarized using descriptive statistics and compared with national averages using χ 2 test of independence. RESULTS: A total of 78 babies were born to 53 AIS patients. As part of their pre-natal care, 24% of patients surveyed reported meeting with an anesthesiologist before delivery. The most common types of delivery were spontaneous vaginal delivery (46%, n=36/78) and planned cesarean section (20%, n=16/78). Compared with the national average, study patients had a higher rate of cesarean delivery ( P =0.021). Of the women who had a spontaneous vaginal birth, 53% had no anesthesia (n=19/36), 19% received intravenous intermittent opioids (n=7/36), and 31% had regional spinal or epidural anesthesia (n=11/36). spontaneous vaginal delivery patients in our study cohort received epidural or spinal anesthesia less frequently than the national average ( P <0.001). Of those (n=26 pregnancies) who did not have regional anesthesia (patients who had no anesthesia or utilized IV intermittent opioids), 19% (n=5 pregnancies) were told by their perinatal providers that it was precluded by previous spine surgery. CONCLUSION: The majority of AIS patients reported not meeting with an anesthesiologist before giving birth and those who had a planned C-section did so under obstetrician recommendation. The presence of instrumentation after spinal fusion should be avoided with attempted access to the spinal canal but should not dictate a delivery plan. A multidisciplinary team consisting of obstetrician, anesthesiologist, and orthopaedic surgeon can provide the most comprehensive information to empower a patient to make her decisions regarding birth experience anesthesia based on maternal rather than provider preference. LEVEL OF EVIDENCE: IV.

Postoperative complications following Schwab-grade-I versus Schwab-grade-II PCO in treating severe rigid kyphoscoliosis patients: comparative matched-group outcomes with minimum 2-year follow-up.

BACKGROUND CONTEXT: Standard partial facetectomies, (Smith-Petersen Osteotomy, (SPO), (Schwab-grade-I) and complete facet resection also known as Ponte osteotomy, (PO), (Schwab-grade-II) are narrowly akin and collectively appreciated as posterior column shortening osteotomies (PCOs). The former is considered a gentler osteotomy grade than the latter. The spine literature provides very little information on their comparison regarding perioperative complications and major curve correction rate outcomes. PURPOSE: To determine whether Schwab-grade-I PCO (SPO) and Schwab-grade-II PCO (PO) are comparably safe in the surgical management of severe rigid scoliosis or kyphoscoliosis patients. STUDY DESIGN/SETTING: Retrospective single-center comparative clinical study. PATIENT SAMPLE: A total of 38 patients with severe rigid scoliosis or kyphoscoliosis were propensity score matched in this study, (SPO-treated); n=21 (55.30%) and (PO-treated); n=17 (44.70%), who underwent primary spinal deformity corrective surgery, respectively. OUTCOME MEASURES: Outcomes included demographics, baseline pulmonary functional outcomes, perioperative complications incidence, hospital costs, Oswestry disability index (ODI), and the Scoliosis Research Society-22 (SRS-22) questionnaire scores. METHODS: Following approval by the Institutional Review Board (IRB) of Beijing Chaoyang Hospital-Affiliated Capital Medical University in Beijing, out of a total of 82 consecutive surgical patients with complete data demonstrating severe and/or rigid spinal deformity, a pool of 38 of the 82 (46.3%) propensity-matched adult (≥18 years) patients with severe rigid scoliosis or kyphoscoliosis defined with a preoperative major curve magnitude of ≥80° on anteroposterior plain radiographs, and flexibility of <25% on bending plain radiographs who underwent primary spinal deformity corrective surgery were retrospectively evaluated. The patients were dichotomized into two osteotomy groups: standard (partial) facetectomy (SPO-treated), n=21 with an average age of 24.67 years, (Schwab-grade-I PCO) and complete facet excision, (PO-treated), (ie, Schwab-grade-II PCO), n=17 with an average age of 23.12 years. The minimum follow-up period was 2 years. Primary outcomes included baseline demographics and clinical features. Secondary outcomes included perioperative [intraoperative, immediate, and 2-year postoperative] complication rates. Tertiary outcomes included perioperative ODI and SRS-22 scores. Statistical analyses were carried out by Student t-test and Pearson's Chi-square test (Fisher's Exact Test), through Python statistical software package. Statistical significance was set at (p<.05). RESULTS: Of the 38 matched severe rigid scoliosis or kyphoscoliosis patients, 55.30% (n=21) were SPO-treated and 44.70% (n=17) were PO-treated patients, respectively. The overall average age of patients was 23.97 years, with a female incidence of 76.32%. Major curve correction rates were 49.19% and 57.40% in SPO-treated and PO-treated patients, respectively, (p>.05). Immediately following surgery, comparable overall complication rates of 28.57% (n=6/21) versus 29.41% (n=5/17) were observed in the SPO-treated and PO-treated patients, respectively, (p=.726). We observed incidences of 9.52%, (n=2/21) versus 5.88%, (n=1/17) for surgical intensive care unit (SICU) admission, and incidences of 4.76%, (n=1/21) versus 5.88%, (n=1/17) for cardiopulmonary events in SPO-treated versus PO-treated patients following corrective surgery, respectively, (p>.05). The incidences of neurological deficits in the SPO-treated and PO-treated patients were respectively, 14.29%, (n=3/21) versus 17.65%, (n=3/17) immediately following surgery, (p>.05), and 0.00%, (n=0/21) in SPO-treated versus 14.28%, (n=3/21) in PO-treated patients at ≥2 years postoperative, (p<.05). Among the three patients that reported neurological deficits in the PO-treated group at ≥2 years postoperative, two patients had pre-existing baseline neurological deficits. The ODI score in the PO-treated group was significantly inferior at a minimum 2-year follow-up, (p<.05). CONCLUSIONS: In the current study, both SPO-treated and PO-treated patients demonstrated statistically comparable surgical complications immediately following corrective surgery. Severe rigid kyphoscoliosis patients with preexisting baseline neurological deficits were more inclined to sustain neurological morbidity following corrective surgery. PCO corrective techniques are warranted as safe options for treating patients with severe rigid spine deformity phenotypes.

Evaluating Adult Idiopathic Scoliosis as an Independent Risk Factor for Critical Illness in SARS-CoV-2 Infection.

BACKGROUND: Thoracic spinal deformities may reduce chest wall compliance, leading to respiratory complications. The first SARS-CoV-2 (L-variant) strain caused critical respiratory illness, especially in vulnerable patients. This study investigates the association between scoliosis and SARS-CoV-2 (COVID-19) disease course severity. METHODS: Clinical data of 129 patients treated between March 2020 to June 2021 who received a positive COVID-19 polymerase chain reaction result from Mount Sinai and had a scoliosis ICD-10 code (M41.0-M41.9) was retrospectively analyzed. Degree of coronal plane scoliosis on imaging was confirmed by 2 independent measurers and grouped into no scoliosis (Cobb angle <10°), mild (10°-24°), moderate (25°-39°), and severe (>40°) cohorts. Baseline characteristics were compared, and a multivariable logistic regression controlling for clinically significant comorbidities examined the significance of scoliosis as an independent risk factor for hospitalization, intensive care unit (ICU) admission, acute respiratory distress syndrome (ARDS), mechanical ventilation, and mortality. RESULTS: The no (n = 42), mild (n = 14), moderate (n = 44), and severe scoliosis (n = 29) cohorts differed significantly only in age (P = 0.026). The percentage of patients hospitalized (P = 0.59), admitted to the ICU (P = 0.33), developing ARDS (P = 0.77), requiring mechanical ventilation (P = 1.0), or who expired (P = 0.77) did not significantly differ between cohorts. The scoliosis cohorts did not have a significantly higher likelihood of hospital admission (mild P = 0.19, moderate P = 0.67, severe P = 0.98), ICU admission (P = 0.97, P = 0.94, P = 0.22), ARDS (P = 0.87, P = 0.74, P = 0.94), mechanical ventilation (P = 0.73, P = 0.69, P = 0.70), or mortality (P = 0.74, P = 0.87, P = 0.66) than the no scoliosis cohort. CONCLUSIONS: Scoliosis was not an independent risk factor for critical COVID-19 illness. No trends indicated any consistent effect of degree of scoliosis on increased adverse outcome likelihood.

Operative choices matter: the role of UIV and sagittal balance in the development of proximal junctional kyphosis following posterior instrumentation for Scheuermann's kyphosis.

PURPOSE: This study sought to investigate associations between upper instrumented vertebra (UIV) location and the risk of proximal junctional kyphosis (PJK) at 2 years following posterior spinal fusion (PSF) for Scheuermann's kyphosis (SK). METHODS: In this retrospective cohort study, SK patients who underwent PSF and reached 2 years postop were identified in a multicenter international registry, excluding those with anterior release, prior spine surgery, neuromuscular comorbidity, post-traumatic kyphosis, or kyphosis apex below T11-T12. Location of UIV as well as the number of levels between UIV and preoperative kyphosis apex was determined. Additionally, the degree of kyphosis correction was evaluated. PJK was defined as a proximal junctional angle ≥ 10° that is ≥ 10° greater than the preoperative measurement. RESULTS: 90 patients (16.5 ± 1.9 yo, 65.6% male) were included. Preoperative and 2-year postoperative major kyphosis was 74.6 ± 11.6° and 45.9 ± 10.5°, respectively. Twenty-two (24.4%) patients developed PJK at 2 years. Patients with UIV below T2 had a 2.09 times increased risk of PJK when compared to those with UIV at or above T2, adjusting for distance between UIV and preoperative kyphosis apex [95% Confidence Interval (CI) 0.94; 4.63, p = 0.070]. Patients with UIV ≤ 4.5 vertebrae from the apex had a 1.57 times increased risk of PJK, adjusting for UIV relative to T2 [95% CI 0.64; 3.87, p = 0.326]. CONCLUSION: SK patients with UIV below T2 had an increased risk of developing PJK at 2 years following PSF. This association supports consideration of UIV location during preoperative planning. LEVEL OF EVIDENCE: Prognostic Level II.

Surgical Outcomes of Cerebral Palsy Patients With Scoliosis and Lumbar Hyperlordosis: A Comparative Analysis With 2-year Minimum Follow-up.

STUDY DESIGN: Retrospective review of a prospectively collected multicenter database. OBJECTIVE: To compare outcomes of patients with cerebral palsy (CP) who undergo surgery for scoliosis with normal lordosis (NL) versus hyperlordosis. SUMMARY OF BACKGROUND DATA: Surgical correction of scoliosis with lumbar hyperlordosis is challenging. Hyperlordosis may confer higher perioperative morbidity, but this is not well understood. MATERIALS AND METHODS: A multicenter database was queried for CP patients who underwent surgery from 2008 to 2017. The minimum follow-up was 2 years. Two groups were identified: lumbar lordosis <75° (NL) versus ≥ 75° hyperlordosis (HL). Perioperative, radiographic, and clinical outcomes were compared. RESULTS: Two hundred seventy-five patients were studied: 236 NL and 39 HL (-75 to -125°). The mean age was 14.1 years, and 52.4% were male. Patients with hyperlordosis had less cognitive impairment (76.9% vs. 94.0%, P =0.008) and higher CPCHILD scores (59.4 vs. 51.0, P =0.003). Other demographics were similar between the groups. Patients with hyperlordosis had greater lumbar lordosis (-90.5 vs. -31.5°, P <0.001) and smaller sagittal vertical axis (-4.0 vs. 2.6 cm, P <0.001). Patients with hyperlordosis had greater estimated blood loss (2222.0 vs. 1460.7 mL, P <0.001) but a similar perioperative complication rate (20.5% vs. 22.5%, P =0.787). Significant correction of all radiographic parameters was achieved in both groups. The HL group had postoperative lumbar lordosis of -68.2° and sagittal vertical axis of -1.0 cm. At a 2-year follow-up, patients with hyperlordosis continued to have higher CPCHILD scores and gained the greatest benefit in overall quality of life measures (20.0 vs. 6.1, P =0.008). The reoperation rate was 10.2%: implant failure (3.6%), pseudarthrosis (0.7%), and wound complications (7.3%). There were no differences in the reoperation rate between the groups. CONCLUSION: Surgical correction of scoliosis with hyperlordosis is associated with greater estimated blood loss but similar radiographic results, perioperative morbidity, and reoperation rate as normal lordosis. Patients with hyperlordosis gained greater overall health benefits. Correction of ≥25% of hyperlordosis seems satisfactory. LEVEL OF EVIDENCE: 3.

Comparison of Overall Complication Rates in VCR-Based vs Non-VCR-Based Corrective Techniques in Severe Rigid Kyphoscoliosis Patients: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Compilation of complication outcomes data from the surgical management of severe rigid kyphoscoliosis patients using VCR-based vs non-VCR-based corrective maneuvers is lacking. This meta-analysis aimed to compare complication outcomes between those classified osteotomy approaches. METHODS: Thorough literature review and meta-analysis were conducted between January 2000 and September 2021. The selection criteria were studies: i) reporting major curve Cobb angle of ≥80° and flexibility of <25% or 30%; ii) comparing VCR or ≥ Type V Schwab osteotomy defined as VCR-based vs [non-VCR-based] techniques, (any osteotomy or technique other than VCR); iii) published in English with ≥10 patients; iv) reporting complication rates; and v) having minimum of 2-year follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Significance level was set at (P < .05). RESULTS: Of the 174 patients included, 52.30% (n = 91) and 47.70% (n = 83) were VCR-based and non-VCR-based, respectively. The incidence of dural tears/nerve injuries/significant intraoperative-neuromonitoring changes was significantly higher; [OR = 6.78, CI= (1.75 to 26.17), I2 = 0%, (P = .006)] in the VCR-based group than the non-VCR-based group. The 'overall surgical and medical' complication rate was significantly higher in the VCR-based group, [OR = 1.94, CI= (1.02 to 3.67), I2 = 31%, (P = .04)]. CONCLUSION: Both VCR-based and non-VCR-based surgical techniques for management of severe rigid scoliosis and kyphoscoliosis patients pose comparable overall surgical complication rates, while a significantly higher perioperative neurological complication incidence was associated with VCR-based technique compared to the non-VCR-based techniques. The VCR-based technique was associated with 6.78 times higher incidence of neurological complications compared to non-VCR-based techniques.

Anterior Vertebral Body Tethering for Scoliosis Patients With and Without Skeletal Growth Remaining: A Retrospective Review With Minimum 2-Year Follow-Up.

BACKGROUND: Anterior vertebral body tethering (AVBT) has been approved for skeletally immature (IM) adolescent idiopathic scoliosis patients, but the role of AVBT in patients with minimal remaining skeletal growth is controversial. The purpose of this study was to compare minimum 2-year (YR2) outcomes in skeletally IM patients vs those with minimal remaining skeletal growth. METHODS: Patients with single thoracic AVBT were grouped by their preoperative (PR) skeletal maturity: IM (n = 16, Risser 0-2) vs mature (M, n = 19, Risser 3-5). Outcomes were assessed at PR, first erect (FE), and YR2. Median (range) was compared with nonparametric tests (P < 0.05). RESULTS: The PR age was 12.5 (9-16) vs 15 (12-18) years with major Cobb 51° (36°-69°) and 49° (40°-69°) for IM and M, respectively. At FE, there was no difference in correction; however, at YR2, the IM group yielded a lower residual curve (15° [-16° to 38°] vs 29° [12°-42°], P = 0.008). Thoracolumbar/lumbar curves were corrected without group differences. Clinically successful correction (<35°) (15 [94%] vs 15 [79%]) and suspected cord breakages (2 [13%] vs 2 [12%]) were similar at YR2. Two overcorrections occurred, both in IM patients. Scoliosis Research Society-22 outcomes at final follow-up were similar between groups. No revision reoperations or conversions to spinal fusion were needed. CONCLUSIONS: Skeletally IM patients benefit from greater growth-modulated curve correction than M patients, however, at the increased risk of overcorrection. M patients maintained clinically significant correction at latest follow-up. Longer-term follow-up is required to determine durability of outcomes for patients undergoing AVBT who have minimal remaining growth at the time of index surgery. CLINICAL RELEVANCE: This study is relevant to spine surgeons, spine physiotherapists, and patients with idiopathic scoliosis. It offers evidence of clinical correction of scoliosis in mature patients.

Spontaneous Lumbar Curve Correction Following Vertebral Body Tethering of Main Thoracic Curves.

BACKGROUND: Growth modulation through anterior vertebral body tethering (AVBT) has emerged as a fusionless option for the treatment of progressive scoliosis. When tethering the main thoracic curve, the compensatory thoracolumbar/lumbar curve must correct indirectly as a result. The present study evaluated the response of these lumbar curves following AVBT of the main thoracic curves. METHODS: Patients who underwent thoracic AVBT and who had a minimum follow-up of 2 years were included. Magnitudes of the thoracic and lumbar curves were recorded preoperatively and at the first-erect and 2-year postoperative visits. Lumbar curves were further stratified according to their lumbar modifier (A, B, or C). Analysis of variance (ANOVA) and repeated-measures ANOVA were performed to compare correction rates, and the Pearson coefficient was utilized to determine the correlation between the tethered thoracic curve and uninstrumented lumbar curve magnitudes. RESULTS: A total of 218 patients were included. Thoracic curve correction was 40% at the first-erect visit and 43% at 2 years (p = 0.012). Lumbar correction was 30%, 26%, and 18% at the first-erect visit (p < 0.001 for all compared with preoperatively) and minimally changed at 31%, 26%, and 24% at 2 years for lumbar modifiers A, B, and C, respectively. A total of 118 patients (54%) showed thoracic curve improvement between the first-erect and 2-year visits. In a subgroup analysis, these patients had a correction in lumbar curve magnitude from preoperatively to the first-erect visit of 30%, 22%, and 16% for lumbar modifiers A, B, C, respectively, that increased to 42%, 34%, and 31% at 2 years, with strong correlation to thoracic correction at 2-year follow-up (r = 0.557, p < 0.001). CONCLUSIONS: Although there was immediate lumbar correction following AVBT of a main thoracic curve, further improvement following initial correction was only observed among patients with growth modulation of the thoracic curve. Considering all patients, the uninstrumented lumbar curve corrected 30% at 2 years and the instrumented thoracic curve corrected 40%. As indications for AVBT are refined, these data will provide insight into the response of the uninstrumented lumbar curve. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Vertebral Body Tethering in 49 Adolescent Patients after Peak Height Velocity for the Treatment of Idiopathic Scoliosis: 2-5 Year Follow-Up.

Vertebral Body Tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis (AIS) that elicits correction via growth modulation in skeletally immature patients. VBT after peak height velocity is controversial and is the subject of this study. A retrospective review of Risser 3−5 AIS patients treated with VBT, and min. 2-year FU was performed. Pre to post-op changes in clinical outcomes were compared using Student's t-test or the Mann-Whitney test. A total of 49 patients met criteria, age 15.0 ± 1.9 years, FU 32.5 ± 9.1 months. For thoracic (T) major curvatures, T curvature improved from 51.1 ± 6.9° to 27.2° ± 8.1° (p < 0.01) and TL from 37.2° ± 10.7° to 19.2° ± 6.8° (p < 0.01). For thoracolumbar (TL) major curvatures, T improved from 37.2° ± 10.7° to 18.8° ± 9.4° (p < 0.01) and TL from 49.0° ± 6.4° to 20.1° ± 8.5° (p < 0.01). Major curve inclinometer measurements and SRS-22 domains, except activity, improved significantly (p ≤ 0.05). At the latest FU, one (2%) patient required fusion of the T curve and revision of the TL tether due to curve progression in the previously uninstrumented T curve and tether breakage (TB) in the TL. Twenty (41%) patients experienced TB. VBT in AIS patients with limited remaining skeletal growth resulted in satisfactory clinical outcomes at the latest FU.

Pedicle Screw Plowing in Adolescent Idiopathic Scoliosis: How Common Is It and Is It a Problem?

STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: To calculate overall incidence of pedicle screw "plowing" in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF). To identify risk factors for pedicle screw plowing and associated postoperative outcomes, including loss of correction and revision rate. SUMMARY OF BACKGROUND DATA: Curve correction of AIS generates perpendicular stresses that can cause pedicle screws to lose alignment and "plow" through pedicles craniocaudally. METHODS: We reviewed records of 1057 patients who underwent PSF for AIS from 2002 to 2015. Preoperative and first postoperative erect radiographs were evaluated by two observers to determine (1) presence of plowing and (2) subsequent loss of correction (LOC). Plowing was defined as more than 25° sagittal angulation compared with pedicle axis or entry of the most dorsal part of the screw outside the pedicle projection. LOC was defined as postoperative change in focal angulation of an instrumented spinal level, when in consensus of both reviewers. Bivariate analyses were performed (alpha = 0.05). RESULTS: Nineteen thousand five hundred sixty nine screws were assessed across our cohort of 1057 patients. Both observers agreed that 48 patients (4.5%) demonstrated plowing of more than or equal to one pedicle screw. For 72 screws (0.4%), both observers noted plowing, most commonly through the cranial cortex of the pedicle (65/72 screws) and at the lowest instrument vertebra (LIV) (17/72 screws). Factors associated with plowing included larger curves (P = 0.02); lower mean pedicle screw density (P = 0.0003); skeletal immaturity as measured by open triradiate cartilage (P = 0.04); and younger chronological age at time of surgery (P = 0.04). LOC occurred in 13 patients, most commonly at LIV (P < 0.0001). Revision rate for loss of screw fixation was higher in the plowing group (P = 0.003). CONCLUSION: Pedicle screw plowing occurred in 4.5% of AIS patients, especially in those skeletally immature and with decreased implant density. Plowing commonly occurred in the cranial direction and was associated with LOC, particularly at the LIV.Level of Evidence: 3.

Ten-year follow-up of Lenke 5 curves treated with spinal fusion.

INTRODUCTION: Patients with surgically treated Lenke 5 curves require at least partial fusion of the lumbar spine. The implications of lumbar fusion remain unknown as long-term follow-up is sparse. METHODS: A retrospective review of a prospectively collected registry of patients with Lenke 5 curves treated with spinal fusion was performed. Clinical and radiographic outcomes as well as SRS-22 scores were collected at 2- and 10-year follow-up. RESULTS: 54 of 247 available patients met all inclusion criteria [26 treated with posterior spinal fusion (PSF) and 28 with anterior spinal fusion (ASF)]. Preoperative lumbar curve magnitude was 45.1 ± 8.4° and corrected to 14.0 ± 7.2° (p < 0.001). A 3.3 ± 7.3° increase in curve size was noted at final follow-up (p < 0.008) with 20.3% of patients having a loss of correction (LOC)of 10° or more. Thoracic curve correction and kyphosis were stable at 10-year follow-up. End vertebrae angulation improved from 11.2 ± 23.2° to 0.96 ± 6.4° (p = 0.004) and translation improved from 2.5 ± 2.9 to 0.92 ± 1.5 cm (p = 0.008) with no LOC. Disc wedging below the lower instrumented vertebrae increased from 0.3 ± 4.9° to 2.8 ± 4.4° (p < 0.001) with no change at 10 years. SRS-22 self-image and satisfaction improved from post-operative to final follow-up. No patient required a second operation. CONCLUSIONS: Both ASF and PSF showed durable results at 10-year follow-up with no obvious difference between approaches. 20% of patients had a LOC > 10°; this did not correlate with pain or need for revision surgery. Disc wedging was stable. Selection of LIV did not correlate with pain scores. LEVEL OF EVIDENCE: Level III.

Complications following surgical treatment of adolescent idiopathic scoliosis: a 10-year prospective follow-up study.

BACKGROUND: Accurate reporting of long-term complications of surgical treatment of adolescent idiopathic scoliosis (AIS) is critical, but incomplete. This study aimed to report on the rate of complications following surgical treatment of AIS among patients with at least 10 years of follow-up. METHODS: This was a retrospective review of prospectively collected data from a multicenter registry of patients who underwent surgical treatment for AIS with minimum 10-year follow-up. Previously published complications were defined as major if they resulted in reoperation, prolonged hospital stay/readmission, neurological deficits, or were considered life-threatening. Rates and causes of reoperations were also reviewed. RESULTS: Two hundred and eighty-two patients were identified with mean age at surgery of 14.6 ± 2.1 years. Mean follow-up was 10.6 (range 9.5-14) years. Eighty-seven patients had anterior spinal fusion (ASF); 195 had posterior spinal fusion (PSF). The overall major complication rate was 9.9% (n = 28) in 27 patients. Among PSF patients, the complication rate was 9.7% (n = 19) in 18 patients. The complications were surgical site infection (37%), adding-on (26%), pulmonary (16%), neurologic (11%), instrumentation (5%), and gastrointestinal (5%). In ASF patients, the complication rate was 10.3% (n = 9) among nine patients. The complications were pulmonary (44%), pseudoarthrosis (22%), neurologic (11%), adding-on (11%), and gastrointestinal (11%). The reoperation rate was 6.0% (n = 17) among 17 patients. Although most of the complications presented within the first 2 years (60.7%), surgical site infection and adding-on were also seen late into the 10-year period. CONCLUSION: This is the largest prospective study with at least a 10-year follow-up of complications following spinal fusion for AIS, the overall major complication rate was 9.9% with a reoperation rate of 6.0%. Complications presented throughout the 10-year period, making long-term follow-up very important for surveillance. LEVEL OF EVIDENCE: Therapeutic II.

Post-operative tranexamic acid decreases chest tube drainage following vertebral body tethering surgery for scoliosis correction.

PURPOSE: Anterior vertebral body tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis requiring chest tube(s) (CT). We sought to assess the efficacy of post-op intravenous tranexamic acid (IV TXA) in reducing CT drainage and retention. METHODS: 35 VBT patients received 24 h of post-op IV TXA (2 mg/kg/h) were compared to 49 who did not. Group comparisons were performed using Wilcoxon rank-sum and chi-squared tests. Multivariate linear regression analysis was used to assess the relationships between TXA and both CT drainage and retention time. RESULTS: There were no group differences at baseline (Table). CTs placed for thoracic (T) and thoracolumbar (TL) curves were assessed separately. For TH CT, there was less total CT drainage in the TXA group (TXA 569.4 ± 337.4 mL vs. Non-TXA 782.5 ± 338.9 mL; p = 0.003) and shorter CT retention time (TXA 3.0 ± 1.3 vs. Non-TXA 3.9 ± 1.4 days; p = 0.003). For TL CT, there was less total CT drainage in the TXA group (TXA 206.8 ± 152.2 mL vs. Non-TXA 395.7 ± 196.1 mL; p = 0.003) and shorter CT retention time (TXA 1.7 ± 1.3 vs. Non-TXA 2.7 ± 1.0 days; p = 0.001). Following multivariate analysis, use of TXA was the only significant predictor of both drainage in T and TL CTs (p = 0.012 and p = 0.002, respectively) as well as T and TL CT retention time (p = 0.008 and p = 0.009, respectively). There were no differences in LOS (p = 0.863) or ICU stay (p = 0.290). CONCLUSION: IV TXA results in a significant decrease in CT drainage and retention time. CT retention is decreased by 1 day for those that receive TXA. LEVEL OF EVIDENCE: III.

Vertebral Body Tethering: Rationale, Results, and Revision.

Vertebral body tethering is a nonfusion technique for the surgical correction of adolescent idiopathic scoliosis. For skeletally immature patients for whom vertebral body tethering is indicated, it is an alternative option to the gold standard posterior spinal fusion (PSF) and may at least partially preserve motion in instrumented segments of the spine. Benefits of the procedure include the possibility of avoiding the long-term sequelae of PSF such as adjacent segment disease and proximal junctional kyphosis. Recent retrospective case series of vertebral body tethering have shown promising results with correction rates up to 70% but greater variability in outcomes compared with PSF. The complication profile of the procedure also appears to differ from PSF with tether breakage and overcorrection as primary concerns in addition to approach-related complications. Although early outcomes have been promising, additional studies to optimize surgical timing, long-term outcomes, and the possible role of tethering in the more skeletally mature patient are required.