Percent Curve Correction Research Articles

What Happens After a Vertebral Body Tether Break? Incidence, Location, and Progression with 5-Year Follow-up.

Retrospective review. To study risk factors for anterior vertebral body tether (VBT) breakage. VBT is used to treat adolescent idiopathic scoliosis (AIS) in skeletally immature patients. However, tethers break in up to 48% of cases. We reviewed 63 patients who underwent thoracic and/or lumbar VBT with minimum 5-year follow-up. We radiographically characterized suspected tether breaks as a change in inter-screw angle (ISA) >5°. Demographic, radiographic, and clinical risk factors for presumed VBT breaks were evaluated. In confirmed VBT breaks, the average ISA change was 8.1° and segmental coronal curve change was 13.6°, with high correlation (r=0.82). Our presumed VBT break cohort constituted 50 thoracic tethers, 4 lumbar tethers, and 9 combined thoracic/lumbar tethers; the average age was 12.1±1.2 years and mean follow-up of 73.1±11.7 months. Of 59 patients with thoracic VBTs, 12 patients (20.3%) had a total of 18 breaks. Eleven thoracic breaks (61.1%) occurred between 2-5 years postoperatively, and 15 (83.3%) occurred below the curve apex (P<0.05). Timing of thoracic VBT breakage moderately correlated with more distal breaks (r=0.35). Of 13 patients who underwent lumbar VBT, 8 patients (61.5%) had a total of 12 presumed breaks. Six lumbar breaks (50%) occurred between 1-2 years postoperatively, and 7 (58.3%) occurred at or distal to the apex. Age, gender, BMI, Risser score, and curve flexibility were not associated with VBT breaks, but the association between percent curve correction and thoracic VBT breakage trended toward significance (P=0.054). Lumbar VBTs were more likely to break than thoracic VBTs (P=0.016). Seven of the patients with presumed VBT breaks (35%) underwent revision surgery. Lumbar VBTs broke with greater frequency than thoracic VBTs, and VBT breaks typically occurred at levels distal to the curve apex. Only 15% of all patients required revision. 3.

Degree of Postoperative Curve Correction Decreases Risks of Postoperative Pneumonia in Patients Undergoing Both Fusion and Growth-friendly Surgical Treatment of Neuromuscular Scoliosis.

Due to a combination of poor respiratory muscle control and mechanical lung compression secondary to spine and chest wall deformities, patients with neuromuscular (NM) early-onset scoliosis (EOS) are at a high risk for pulmonary complications including pneumonia. The purpose of this study is to examine the effect of surgical intervention on the prevalence and risk of postoperative pneumonia in patients with NM EOS. In this retrospective cohort study, pediatric (18 y old and below) patients with NM EOS undergoing index fusion or growth-friendly instrumentation from 2000 to 2018 were identified. Patients were then categorized into 2 groups: those with ≥50% curve correction and those with <50% curve correction of the coronal deformity at the first postoperative visit. The primary outcome of interest was postoperative pneumonia occurring between 3 weeks and 2 years postoperatively. Manual chart review was supplemented with phone call surveys to ensure all occurrences of preoperative/postoperative pneumonia (ie, in-institution and out-of-institution visits) were accounted for. A total of 35 patients (31% female, age at surgery: 10.3±4.3 y) with NM EOS met inclusion criteria. Twenty-three (66%) patients experienced at least 1 case of preoperative pneumonia. Twenty-six (74%) patients had ≥50% and 9 (26%) patients had <50% immediate postoperative curve correction. In total, 12 (34%) patients experienced at least 1 case of postoperative pneumonia (7 in-institution, 5 out-of-institution). Seven (27%) patients with ≥50% curve correction versus 5 (56%) with <50% curve correction experienced postoperative pneumonia. Relative risk regression demonstrated that patients with <50% curve correction had increased risk of postoperative pneumonia by 2.1 times compared with patients with ≥50% curve correction (95% confidence interval: 0.9; 4.9, P =0.099). The prevalence of preoperative and postoperative pneumonia is high in patients with NM EOS. This study presents preliminary evidence suggesting that percent curve correction is associated with the occurrence of postoperative pneumonia in patients with NM EOS undergoing surgical correction.

No difference in postoperative complication rates or cardiopulmonary function for early versus late scoliosis correction in Duchenne muscular dystrophy

Given reduced rates of both pulmonary function decline and scoliosis progression with steroid treatment in Duchenne muscular dystrophy (DMD), the role of early scoliosis surgery has been questioned. The purpose of this study was to compare the postoperative complication rates of early versus late scoliosis correction in DMD. This study was a retrospective cohort, conducted at an academic tertiary level children's hospital. Patients with DMD who underwent posterior scoliosis correction, with preoperative pulmonary function testing [forced vital capacity (FVC)] were included and divided into two groups by preoperative curve angles: ≤ 45° and > 45°. The primary outcome variable was postoperative complications by Clavien-Dindo classification grading. Secondary outcome variables included postoperative complications occurring after the first 90days, age at surgery, duration of wheelchair dependency preoperatively, pulmonary function, steroid utilization, shortening fraction by echocardiogram, surgery duration, intensive care unit/hospital length of stay, days intubated, infection, and percent curve correction. Two-tailed t-test and Chi-square testing were used for analysis of patient factors and Clavien-Dindo complication grade, respectively. Thirty-one patients were included with a total follow-up of 8.3 ± 3.2years, 4.8 ± 2.2years post-spinal fusion. Steroid treatment (prednisone, deflazacort) was utilized for 21 (67.7%) patients. Primary curve correction was not different between groups (65.0% vs 71.4% [p = 0.37]). There were no significant differences in Clavien-Dindo classification grades between groups (p > 0.05). For the entire cohort, the overall complication rate was higher for patients with steroid treatment (61.9% vs 10.0% [p = 0.008]). Neither forced vital capacity nor fractional shortening on echocardiogram was different between groups at final follow-up (p = 0.6 and p = 0.4, respectively). The comparable risk of perioperative complications for early and late scoliosis correction supports a "watchful waiting" approach, whereby curves less than 45° can be carefully followed while cardiopulmonary function is maintained. Patients undergoing steroid treatment should be counseled regarding the higher risk of postoperative blood transfusion and deep wound infection. III Retrospective cohort.

A Two-Surgeon Approach Improves Performance for Young Surgeons in Adolescent Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS) is a complex 3-dimensional deformity. Previous studies have suggested a learning curve in the successful execution of this technically demanding procedure. A 2-surgeon model may be helpful for less experienced surgeons by facilitating greater consistency in surgical metrics. The objective of this study was to show no significant difference in the parameters examined for surgeries done by inexperienced primary surgeons with a 2-surgeon model compared with those done by their more experienced cohorts. All surgeries with a primary diagnosis of AIS that were performed from January 2012 to December 2015 and had a minimum of 2-year follow-up were included for analysis. Three groups were created based on surgeon experience: inexperienced surgeons (IS) group, experienced surgeons (ES) group, and a third group where the primary surgeon was in the experienced group and the assistant surgeon was in the inexperienced group (EIS). Variables included for analysis were age, Lenke classification, number of levels fused, length of surgery, length of stay, percent curve correction, ratio of estimated blood loss to levels fused, surgical blood loss, and complications. There were no significant differences between the groups in terms of operative time, blood loss, number of levels fused, lower estimated blood loss ratio to the number of levels fused, or percent curve correction (P>.05). The IS group was found to have a significant shorter length of stay (P=.004). The 2-surgeon model is an effective tool for inexperienced surgeons to achieve consistent and reproducible operative performance that is comparable with their more experienced peers. [Orthopedics. 2021;44(3):e347-e352.].

Higher pedicle screw density does not improve curve correction in Lenke 2 adolescent idiopathic scoliosis

PurposeHigher pedicle screw density posterior spinal fusion (PSF) constructs have not been shown to result in improved curve correction in Lenke 1 and 5 adolescent idiopathic scoliosis (AIS) but do increase cost. The purpose of this study questioned whether higher screw density constructs improved curve correction and maintenance of correction in Lenke 2 AIS. Secondary goals were to identify predictive factors for correction and postoperative magnitude of curves in Lenke 2 AIS.MethodsWe identified patients 11 to 17 years old who underwent primary PSF for Lenke 2 AIS between 2007 and 2017 who had minimum follow-up of 2 years. Demographic and radiographic data were collected to perform regression and elimination analysis.ResultsThirty patients (21 females, 9 males) were analyzed. Average age and SD at time of surgery was 14.0 ± 1.8 years (range, 11–17 years), and median follow-up was 2.8 years (IQR 2.1–4.0 years). Implant density did not predict final postoperative curve magnitude. Predictors of final postoperative curve magnitude were sex and preoperative curve magnitude. Predictors of percentage of correction of major curve were sex and age at the time of surgery. Predictors of final postoperative thoracic kyphosis were sex and percent flexibility preop. Females had lower final postoperative major curve magnitude, a higher percent curve correction, and lower postoperative thoracic kyphosis.ConclusionsIncreased implant density is not predictive of postoperative curve magnitude in Lenke 2 AIS. Predictors of postoperative curve magnitude are sex and preoperative curve magnitude.Level of evidenceLevel III, retrospective observational

105. ALIF generates better correction of the fractional lumbar curve vs posterior instrumentation alone in spinal deformity fusion to the pelvis

BACKGROUND CONTEXT ALIF is a widely accepted strategy to increase lumbar lordosis and improve fusion. It may also help reduce the fractional lumbar curve. Improved fractional curve correction can level the pelvis and facilitate proximal realignment. PURPOSE To determine if the addition of an anterior lumbar interbody fusion (ALIF) to posterolateral fusion results in a more level pelvis by correcting the fractional lumbar curve. STUDY DESIGN/SETTING Retrospective comparative observational cohort. PATIENT SAMPLE Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity. OUTCOME MEASURES Pre- and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. METHODS Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity were identified and stratified into patients who had an ALIF in addition to PSF (ALIF+PSF) and those who had a posterior instrumented fusion (PSF) only. Radiographic parameters measured included preop and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. RESULTS There were 30 cases in the ALIF+PSF group and 31 in the PSF group. Baseline demographic characteristics of the two groups were similar. Mean preop fractional coronal Cobb (18.2° vs 14.2°, p=0.069), lumbar lordosis (30.9° vs 334.2°, p=0.379) and pelvic parameters were similar between the two groups. Postop lumbar lordosis was similar (48.4° vs 44.1°, p=0.183). Greater fractional coronal curve correction was achieved in the ALIF+PSF group (69%) compared to the PSF group (29%, p CONCLUSIONS There is a greater correction of the fractional curve in the ALIF+PSF group compared with the PSF only group. While this may not be the primary indication for ALIF, it is a benefit that may level the pelvis and facilitate overall deformity correction. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Delayed quadriparesis after posterior spinal fusion for scoliosis: a case series.

A multicenter retrospective IRB exempt case series analyzing clinical and radiographical data of patients treated by three surgeons over the past two decades was conducted. To examine the factors involved in the development of quadriparesis in patients who underwent posterior spinal fusion for scoliosis. Delayed spinal cord infarcts usually present at the region of instrumentation according to reports from the Scoliosis Research Society. Nonetheless, there is a lack of data regarding factors associated with delayed quadriparesis following posterior spinal fusion METHODS: Evaluated variables were age, Cobb angle, blood loss, and curve correction percentage. Postoperative imaging was also evaluated to determine factors indicative of the etiology of the quadriparesis. Eight patients presented delayed postoperative quadriparesis. All patients had a postoperative examination equal to that of baseline. The first patient deteriorated at 6h postoperatively and the most delayed patient presented 4days postoperatively. Six patients had neuromuscular disorders and 2 had adolescent idiopathic scoliosis. Mean age was 13.7, mean curve magnitude was 78.7°, mean percent curve correction was 71% and the mean estimated blood loss was 1185cc. Seven of eight patients had documented peri- or postoperative hypotension. Cervical infarction is the likely cause of delayed quadriparesis after posterior spinal fusion. Even though the underlying etiology continues to be unclear, postoperative hypotension, curve magnitude, percent curve correction, and the presence of cervical kyphosis/stenosis may be contributory and need to be closely evaluated. IV, Case Series.

Short fusion with vertebrectomy during growth in congenital spinal deformity: is early surgical intervention recommended?

This was a multi-center retrospective cohort study included consecutive pediatric patients who were admitted to 8 institutions for the treatment of congenital spinal deformity from 1991 to 2012. The purpose of this study was to compare curve corrections and balances, reoperations, and complications at 2-year follow-up between those treated early vs. late. Although early intervention has been recommended, no empirical study has examined the optimal timing of short fusion among patients with congenital spinal deformity. Patients with congenital spinal deformity with formation failure undergoing vertebrectomy with short fusion (≤ 6 fusion segments) were categorized as early (surgery at ≤ 6years) and late (7-18years) fusion. Outcomes included coronal and sagittal curve corrections at immediate and 2-year evaluations; loss of curve correction from immediate to 2-year follow-up; coronal and sagittal balance at 2years; and inter-operative, major and minor short-term postoperative, and long-term postoperative complications and reoperations. Early fusion (N = 79) compared to late fusion (N = 96) was associated with greater percent curve correction at immediate (71% vs. 60%, p = 0.0046) and 2-year (63% vs. 52%, p = 0.0153) evaluations adjusting for surgeon experience and preoperative coronal balance. These associations were significant for males and those with 3-level fusions but not 4 to 6-level fusions. Early fusion compared with late fusion had more intraoperative (6% vs. 1%) and postoperative long-term complications (27% vs. 18%), as well as unplanned reoperations (13% vs. 9%). Early vs. late fusion had fewer short-term complications, both major (6% vs. 15%) and minor (6% vs. 15%). Patients who underwent early treatment achieved larger major curve correction by 10% compared to patients with late treatment when assessed at 2-year postoperative evaluation. However, early fusion should be considered with careful attention to possible increased risk of reoperations. Level III.

Periapical Wires Result in Less Curve Correction Than Pedicle Screw Constructs in Idiopathic Scoliosis.

Study DesignRetrospective study.PurposeThe objective of this study was to compare percent correction between apical and periapical pedicle screw (PS) and sublaminar wire constructs for Cobb correction and coronal balance correction.Overview of LiteratureThe current gold standard for deformity correction in adolescent idiopathic scoliosis (AIS) are PS constructs. Sublaminar wires provide an alternative means of fixation when PS fixation cannot be safely performed. Two previous studies have compared percent curve correction between sublaminar wires and PSs, with conflicting conclusions.MethodsThe study was a retrospective review of Lenke type 1 curves with minimum follow-up of at least 1 year. Cases were divided into two groups: constructs using apical/periapical sublaminar wires (SL group) versus PS only constructs (PS group). Percent Cobb correction and coronal balance were compared between the two groups at 1 year. A multivariable regression model was used to determine the impact of apical/periapical wires on percent Cobb correction and coronal balance at 1 year when accounting for additional variables.ResultsThe cohort included 71 patients who were predominantly female (80.2%), with average age of 14.2 years. Only 21 (29.5%) of constructs utilized apical/periapical sublaminar wires. There was a significant difference in percent Cobb correction at 1 year for the PS and SL groups (70.26% vs. 60.09%, p=0.05). No difference was observed in overall coronal balance. A multivariable model revealed that apical/periapical wires were negatively associated with percent Cobb correction at 1 year (coefficient=−8.49, p=0.023), while total implant density of the construct was positively associated with correction (coefficient=24.2, p<0.001).Conclusions Use of PSs in the apical and periapical zones resulted in improved percent Cobb correction at 1 year in patients with AIS Lenke type 1 curves. Sublaminar wires remain a useful surgical option and result in equivalent coronal balance compared to PSs.

Low-Density Pedicle Screw Constructs for Adolescent Idiopathic Scoliosis: Evaluation of Effectiveness and Cost.

Study Design:Retrospective cohort study.Objective:To determine whether a low-density (LD) screw construct can achieve curve correction similar to a high-density (HD) construct in adolescent scoliosis.Methods:Patients treated operatively for idiopathic scoliosis between 2007 and 2011 were identified through a database review. A consistent LD screw construct was used. Radiographic assessment included percent correction of major and fractional lumbar curves, T5-T12 kyphosis, and angle of lowest instrumented vertebra (LIV). Costs were compared with HD constructs.Results:Thirty-five patients were included in the analysis. Ages ranged from 12 to 19 years (mean = 14.9 years). Average screw density was 1.2 screws per level (range = 1.07-1.5 screws). Mean percent curve correction at latest follow-up: major curve, 66.9%; fractional lumbar curve, 63%. Average postoperative thoracic kyphosis: 29.5°. Mean LIV angle: 5.6°. Average construct cost was $14 871 per case compared with $23 840 per case if all levels had been instrumented with 2 screws, amounting to an average savings of $9000.Conclusions:Our LD screw construct is among the lowest density constructs reported and achieves curve correction comparable to HD constructs at substantially lower cost.

Three-dimensional correction for idiopathic scoliosis with posterior spinal fusion and the risk of neurological complications

Abstract Introduction The correction of adolescent idiopathic scoliosis (AIS) using the posterior approach is the most common and well-documented technique in medical literature. As with any invasive procedure, it carries the risk of potential neurological complications (NCs). Aim Evaluation of NCs after surgical treatment of AIS and patient satisfaction after surgery. Material and methods A retrospective evaluation of 195 patients operated in 2007–2013 with posterior approach and direct vertebral derotation. We evaluated the age of the patients during the surgery, the angle of the main curvature, the thoracic kyphosis, sex, BMI, the average length of stay in the hospital after surgery, the average percent curve correction, postoperative NCs, and SRS-22 at the final follow-up (FFU). Results The operated patients were 71% female. The average age was 16.5 years. The mean duration of surgery was 330 min. The average amount of blood loss was 820 mL. The average length of stay was 5.5 days. NCs were recorded as follows: numbness of the lateral femoral cutaneous nerve (6), muscle weakness of the lower limbs (5), paraesthesia of the foot (5), lower limb paraesthesia (5), radiculopathy (4), paraparesis (2), and neurogenic bladder (2). All NCs were eliminated in the postoperative period and at FFU, and there were no neurological deficits. SRS-22 scores at FFU were good. Conclusions (1) The rate of NCs is insignificant and left no lasting musculoskeletal dysfunction. (2) Number of complications was higher when we did not use neuromonitoring. (3) Total satisfaction after surgery at FFU was good.

Low-density Pedicle Screw Constructs for Adolescent Idiopathic Scoliosis: Evaluation of Effectiveness and Cost

Introduction Optimal screw density and technique in treatment of idiopathic scoliosis remain unknown. We sought to find if low-density (LD) screw construct can achieve curve correction similar to that achieved with high-density (HD) constructs in adolescent scoliosis at substantial cost savings. Materials and Methods Patients treated operatively for idiopathic scoliosis at our center between 2007 and 2011 were identified through a retrospective database review. Each patient was treated with an LD screw construct. Radiographic outcomes included assessment of screw density, percent correction of major and fractional lumbar curves at follow-up, T5−T12 kyphosis, and angle of lowest instrumented vertebra (LIV). Costs were calculated and compared with costs of HD constructs. Results Forty-five patients met inclusion criteria. Ages ranged from 12 to 19 years (mean age, 14.9 years). Average construct density was 1.2 screws per fused level (range, 1.07−1.33 screws). Mean percent curve correction at latest follow-up: major curve, 67.2%; fractional lumbar curve, 69%. Average postoperative thoracic kyphosis: 30 degrees. Mean LIV angle: 5.6 degrees. Total screw cost was $13,370 per case in the LD group compared with $22,340 per case if all levels had been instrumented with 2 screws. Conclusions Our LD screw construct is among the lowest density constructs reported in the literature and achieves curve correction comparable to that reported for HD constructs at substantially lower cost.

Minimally invasive surgical options for adolescent idiopathic scoliosis

Early results of MIS in AIS have been promising; however, longer-term follow-up data remains limited. Our objective was to compare perioperative outcomes as well as radiographic and clinical outcomes between MIS and standard open posterior spinal instrumentation and fusion (PSIF) at 2-year follow-up. Advantages of MIS in AIS were related to intra-operative blood loss, cell saver transfusion rates, and LOS; however, significant increases in ORT, lower mean percent curve correction, and a higher complication rate of MIS in AIS were also noted. Despite these variations, no clinical differences in SRS-22 scores were found at 2 years postop between the groups.

Prospective Evaluation of Quality of Life in Adolescent Idiopathic Scoliosis Before and After Surgery

Prospective observational study. To assess patient quality of life before and after surgical treatment of adolescent idiopathic scoliosis (AIS) and determine whether an association exists between quality of life and curve magnitude, curve correction, and type of instrumentation. Assessment of AIS surgery outcomes has always been based on analysis of radiographic measurements and postoperative curve correction. However, there is a current trend toward greater emphasis on patient-centered outcomes. Assessment of treatment success on the basis of these outcomes requires prospective use of quality-of-life surveys before and after AIS treatment. Prospective study of 33 patients undergoing surgical treatment of AIS. Mean age was 15.6 years and mean Cobb angle was 70.5 degrees. Patients were randomly allocated into one of 2 instrumentation groups (hybrid and pedicle screws alone), and the Scoliosis Research Society-30 questionnaire (SRS-30) and Short Form-36 Health Survey (SF-36) questionnaires were administered preoperatively and at 3-, 6-, and 12-month follow-up. Statistical testing was performed to determine whether survey scores correlated with Cobb angle, curve correction, or type of instrumentation. SRS-30 and SF-36 scores improved significantly. The greatest changes occurred in the self-image and satisfaction with management domains of the SRS-30 survey. SRS-30 and SF-36 scores showed worsening pain and decreased function at 3-month follow-up, but significant improvement from baseline at 12 months. Total SRS-30 scores were significantly improved at 6- and 12-month follow-up, as were subscores in the general health, vitality, and social functioning domains of SF-36. Curve magnitude, percent curve correction, and type of instrumentation had no significant influence on final SRS-30 and SF-36 scores. Surgical treatment of AIS improved patient quality of life, as shown by significant improvement on all SRS-30 and SF-36 domains. Questionnaire scores did not correlate with Cobb angle, curve correction, or type of instrumentation.

Do Thoracolumbar/lumbar Curves Respond Differently to Growing Rod Surgery Compared With Thoracic Curves?

Study DesignRetrospective study. ObjectivesTo compare radiographic outcomes between primary thoracic and primary thoracolumbar/lumbar curves in patients with early-onset scoliosis (EOS) after growing rod (GR) surgery. Summary of Background DataPrevious studies have shown the efficacy of GR surgery for progressive EOS. However, there is no information on the behavior of different curve patterns in EOS after GR surgery. MethodsA multicenter international EOS database query identified 175 patients who met the following inclusion criteria: non-congenital etiology, GR surgery, ≤ 10 years of age at index surgery, minimum 2-year follow-up, and at least 3 lengthenings. Patients were categorized into 2 groups based on the Scoliosis Research Society definition of the anatomical location of primary curves: group 1 included thoracic apices (T2 to T11/12 disc) and group 2 included thoracolumbar (T12 to L1) and lumbar (L1/2 disc to L4) apices. Radiographic measurements were performed before and after index surgery and at latest follow-up. ResultsA total of 139 patients (79%) had primary thoracic (group 1) and 36 (21%) had primary thoracolumbar or lumbar curves (group 2). Mean number of levels instrumented was statistically greater in group 2 (15.0) versus group 1 (13.6) (p < .05). Group 2 had statistically better mean curve correction than group 1 after the index GR surgery (51% and 44%, respectively; p < .05). However, there was no significant difference in mean percent curve correction at latest follow-up (46% and 39%, respectively; p > .05). Implant complication rate was 45% and 47% for groups 1 and 2, respectively. Preoperative curve flexibility was greater in group 2 (45%) compared with group 1 (40%) (p > .05). ConclusionsOverall, thoracolumbar/lumbar and thoracic curves achieve similar major curve correction and have a similar complication profile.

Increased Body Mass Index Negatively Affects Patient Satisfaction After a Posterior Fusion and Instrumentation for Adolescent Idiopathic Scoliosis

Study DesignRetrospective. Summary of Background DataPrevious studies have reported the correlation of body mass index (BMI) with non-spine surgical outcomes; however, only a few reviewed the correlation of BMI to outcomes after spine surgery. ObjectivesTo review the influence of preoperative BMI on the follow-up clinical and functional outcomes after posterior-only fusion (PSF) and instrumentation for adolescent idiopathic scoliosis in a larger patient cohort. MethodsRetrospective review of a consecutive series of patients treated with PSF for adolescent idiopathic scoliosis from 2002 to 2009 at a single institution. There were 3 categories: underweight (UW), normal weight (NML), and overweight (OW). Percent correction of the major curve was collected at 2 years postoperatively and patient outcome scores were analyzed preoperatively and at 2 years postoperatively. Differences between groups were analyzed using analysis of variance, with p < .05. ResultsA total of 459 patients at an average age of 15.0 years (range, 10.0–21.3 years) treated with PSF instrumentation were included. At 2 years, all groups achieved and maintained equal percent correction with no differences between groups. Regarding preoperative Scoliosis Research Society (SRS) outcome scores, OW patients reported more pain than NML (p = .002) and UW patients (p < .001) despite less reported activity than for the NML (p = .033) and UW groups (p = .005). The total SRS score was also lower in the OW patients compared with NML (p = .009) and UW patients (p = .002). At 2 years, the OW group reported more pain than the UW (p = .031) and NML groups (p = .018), lower mental scores (p = .011) and lower SRS total scores (p = .005) than the NML group. ConclusionsAt follow-up, preoperative overweight adolescents reported more pain and lower mental, activity, and appearance domain scores after surgery than UW and NML patients despite equal percent curve correction. This information may help the surgeon with preoperative counseling of OW patients by stressing that their own assessment of outcome is influenced by BMI, which may help promote a healthy weight management program in this patient group.

Does Higher Anchor Density Result in Increased Curve Correction and Improved Clinical Outcomes in Adolescent Idiopathic Scoliosis?

Retrospective review of prospectively collected data. To determine whether anchor density is associated with curve correction and patient-reported outcomes. There is limited information as to whether anchor density affects the results of adolescent idiopathic scoliosis surgery. A total of 952 patients with adolescent idiopathic scoliosis met inclusion criteria (Lenke 1, 2, and 5 curves) with predominantly screw constructs (no. of screws/no. of total anchors >75%). Anchor density was defined as the number of screws, hooks, and wires per level fused, with less than 1.54 considered low density. Analysis of covariance was undertaken to determine association of anchor density with percent curve correction, Scoliosis Research Society (SRS), and Spinal Appearance Questionnaire (SAQ) scores, controlling for flexibility, fusion length, demographics, and surgeon. High- compared with low-anchor density was associated with increased percent curve correction in Lenke 1 curves at 1 year (69% vs. 66% correction, P = 0.0022), controlling for percent preoperative curve flexibility, length of fusion, and sex (model, P < 0.0001). Similar associations held at 2-year follow-up and for Lenke 2 curves. Decreased thoracic kyphosis was found with increased anchor density for Lenke 1 and 2 curve patterns. There were no associations found between anchor density and Lenke 5 curves. For Lenke 1 curve patterns at 2 years postoperatively, in the high- versus low-anchor density cohorts, there were statistically higher SRS Activity (4.3 vs. 4.2, P = 0.019), Appearance (4.3 vs. 4.1, P = 0.0005), Satisfaction (4.5 vs. 4.3, P = 0.028), and Total scores (4.3 vs. 4.2; P = 0.024). Similarly, the SAQ Appearance score at 1 year similarly was improved in the high-anchor density group (high: 14.1 vs. low: 15.0, P = 0.03) for Lenke 1 curve patterns only. For Lenke 1 and 2 curve patterns, improved percent correction of major coronal curve was noted in the high-screw density cohort. Although statistical significance was reached, it is unclear whether screw density resulted in clinically significant differences in patient-reported outcomes.

Evaluation of High-risk Patients Undergoing Spinal Surgery: A Matched Case Series

Neuromuscular (NM) spinal deformities necessitating surgical intervention present a difficult challenge to the medical community. Underlying comorbidities lead to extended hospital stays, significant complications, and social challenges in the extensive perioperative period. In response to this problem, a therapeutic algorithm, the Care Pathway for Spinal Surgery (CAPSS) has been developed at our institution to address this complex medical issue. In 1999, a multidisciplinary team developed a treatment protocol, CAPSS, that emphasized perioperative work up and operative scheduling under the direction of a dedicated care coordinator. A case series analysis was conducted to compare the surgical outcomes from before and after CAPSS implementation. Statistical analyses were performed on a carefully paired subset of NM patients (N=9). Outcome measures were hospital length of stay (LOS), pediatric intensive care unit LOS, number of days intubated, surgical estimated blood loss, postoperative curve magnitude, percent curve correction, and perioperative complications. Statistical analyses indicated that the use of CAPSS provided significant reduction in overall LOS, pediatric intensive care unit LOS, and perioperative complication rate within this patient group. CAPSS is an effective method to improve perisurgical care within the NM patients with spinal deformity necessitating operative stabilization. III-Retrospective comparative study.

The Effect of Surgical Approaches on Pulmonary Function in Adolescent Idiopathic Scoliosis

Retrospective study. To evaluate the effects of 4 surgical approaches for adolescent idiopathic scoliosis on pulmonary function and document their trend across a 2-year period. Understanding the effects of surgical approaches on pulmonary function is critical in the treatment of adolescent idiopathic scoliosis. Depending on the surgical approach, studies have demonstrated improvement, decline, or no effect on pulmonary function. Sixty-one patients were evaluated for vital capacity (VC) and peak flow (PF) before and following surgery at 1, 3, 6, 12, and 24 months. Patients were separated into the following groups: group 1-posterior fusion only, group 2-posterior fusion with thoracoplasty, group 3-thoracoscopic anterior fusion, group 4-open anterior thoracolumbar fusion. Between groups, no difference was found in age, preoperative curve magnitude, percent curve correction or baseline VC and PF. At 1-month postoperatively, group 3 had lower VC than group 1 (P<0.01). After 1 month, no difference was seen between groups. Compared with before surgery, group 2 demonstrated a significant decline in VC and PF at 1 month and returned to baseline at 3 months (P<0.01). Group 3 had a significant decline in VC and PF at 1, 3, and 6 months whereas group 4 had a decline in VC at 1 month (P<0.01). Scoliosis approaches that violate the chest wall demonstrate a significant decline in postoperative pulmonary function. Documented return of pulmonary function did not occur until 3 months for posterior fusion with thoracoplasty, 3 months for open anterior fusion and 1 year for video-assisted thoracoscopic surgery.

Video-Assisted Anterior Thoracoscopic Spinal Fusion Versus Posterior Spinal Fusion

Retrospective, matched cohort. The purpose of this study was to compare the Scoliosis Research Society's Outcomes measures (SRS-22) scores, as well as radiographic outcomes of patients with adolescent idiopathic scoliosis who had a single thoracic structural curvature treated by either posterior spinal fusion (PSF) or video-assisted thoracoscopic (VATS) fusion. To our knowledge, there has been no prior matched-pair study comparing outcomes between 2 different surgical approaches for the same curve type using the SRS-22 outcomes instrument. Patients were evaluated before surgery and at 2-year follow-up. A total of 52 patients with Lenke type I curvature were paired by age, gender, and major Cobb angle into 2 groups: PSF (8 men, 18 women, mean age 14.7, mean Cobb angle 48.7) and VATS (mean age 14.8, mean Cobb angle 49.1). All questionnaire scores were classified based on domains of activity, pain, self-image, mental health, satisfaction, and total scores. The patients in the VATS group scored higher than the PSF group in the domains of self-image (P < 0.02), mental health (P < 0.03), and total score (P < 0.05), but not activity, pain, or satisfaction at 2 years. There was no difference in percent curve correction between the match-paired groups. Within-group analyses revealed that VATS patients experienced insignificant improvements compared with PSF in most SRS-22 domains and a trend toward significant overall mean score improvement (P = 0.06). Based on the SRS-22 questionnaire data, the VATS patients scored higher in the self-image, mental health, and total domains despite similar curve corrections. We hypothesize that this may be related to the smaller surgical scar and less invasive nature of VATS.