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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.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.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 (p0.001 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, p0.001).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.Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND The purpose of the present study was to evaluate associations between changes in segmental vertebral coronal angulation (screw angulation) and overall height after anterior spinal growth tethering for the treatment of idiopathic scoliosis and to compare the rates of coronal angulation change using the preoperative Sanders stage. METHODS Patients with idiopathic scoliosis who underwent anterior spinal growth tethering between 2012 and 2016 and had ≥2 years of follow-up were retrospectively studied. We calculated each segment's screw angulation rate of change (degrees/month) and each patient's height velocity (cm/month) between each of the visits (3 to 12 visits/patient) and divided the visits into 4 groups by postoperative duration ( 2 to 3 years, >3 years). Patients were divided into 2 groups according to the preoperative Sanders stage. Generalized estimating equations and repeated-measures correlation were utilized for analyses with non-independent samples. RESULTS We analyzed 23 patients (16 female, 7 male) with a mean age (and standard deviation) of 12.2 ± 1.6 years who had right thoracic idiopathic scoliosis (mean, 53° ± 8°). All patients were immature at the time of surgery (Risser stage 0 or 1, Sanders stage 2 or 3). The mean duration of follow-up was 3.4 ± 1.1 years (range, 2 to 5 years). The rate of change for each segment's screw angulation after anterior spinal growth tethering was -0.16°, -0.14°, -0.05°, and 0.03° per month (with negative values indicating a reduction in scoliosis) for 2 to 3 years, and >3 years, respectively (p ≤ 0.001), and the mean height velocity was 0.65, 0.57, 0.30, and 0.19 cm per month for 2 to 3 years, and >3 years, respectively (p < 0.001). Changes in screw angulation correlated with height increases after anterior spinal growth tethering (r = -0.46, p < 0.001). Scoliosis correction for patients in the Sanders stage-2 group continued for 3 years (0.23°, 0.23°, and 0.09° per level per month for the first 3 years, respectively) and occurred at more than twice the rate for patients in the Sanders stage-3 group, for whom scoliosis correction ceased 2 years postoperatively (0.11° and 0.09° per level per month for the first 2 years, respectively). CONCLUSIONS Scoliosis correction was associated with overall height changes and occurred primarily within 2 to 3 years after surgery in this cohort of largely Risser stage-0 patients. The correction rate was 2.8° per segment per year for the first 2 years in the Sanders stage-2 group, compared with 1.2° per segment per year for the Sanders stage-3 group. Surgical timing that considers the patient's skeletal maturity is an important factor in generating proper postoperative correction after anterior spinal growth tethering. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN Retrospective. OBJECTIVE To evaluate the effect of preoperative rod shape on 3D spinal deformity correction. SUMMARY OF BACKGROUND DATA Differential rod contouring is a surgeon-dependent process based on an estimate of 3D deformity correction sought and the flexibility of the spine. An objective measure to this otherwise subjective scoliosis correction technique is lacking. METHODS A series of adolescent idiopathic scoliosis (AIS) patients with right, thoracic major curves, preoperative rod contour tracings, and EOS imaging was evaluated. All patients underwent posterior spinal fusion with 5.5 mm steel rods contoured prior to insertion. 3D reconstructions were generated pre- and postoperatively using sterEOS software (EOS Imaging) and imported into MATLAB (Mathworks) for analysis. A new measurement of the maximum perpendicular distance from the preinsertion concave rod contour to the preoperative 3D sagittal spinal reconstruction was defined as rod to 3D spine distance (RSD). Linear regressions were used to identify relationships between pre and postoperative parameters, including RSD and 3D thoracic kyphosis. RESULTS Ninety-nine patients were included. Average preoperative concave rod angle decreased from (48 ± 10°) preoperatively to 26 ± 6° postoperatively (P

STUDY DESIGN Retrospective review. OBJECTIVE The aim of this study was to determine whether major postoperative complications ("complications") are associated with 2-year improvements in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores after scoliosis surgery, and whether complications and preoperative characteristics predict 2-year improvements in CPCHILD Total score. SUMMARY OF BACKGROUND DATA Spinal arthrodesis can halt the progression of spinal deformity in patients with cerebral palsy (CP)-related scoliosis. However, these patients are prone to postoperative complications. METHODS Using a multicenter CP registry, we identified 222 patients aged ≤21 years who underwent spinal fusion from 2008 to 2015 and had ≥2-year follow-up. We compared CPCHILD score improvement between 71 patients who had 1 or more complications ("complications group") versus 151 who did not ("no-complications group"). Complications were deep infections, thromboembolic events, and cardiopulmonary, gastrointestinal, and neurologic complications. Multiple linear regression was used to identify predictors of 2-year postoperative CPCHILD score improvement (alpha = 0.05). RESULTS At 2-year follow-up, the complications group had similar mean improvement in CPCHILD score across all domains compared with the no-complications group (P > 0.05). When stratifying by complication type, deep infection was associated with less improvement in CPCHILD Comfort and Emotions (P = 0.02), Quality of Life (P

INTRODUCTION It is unclear what factors influence health-related quality of life (HRQOL) in neuromuscular scoliosis. The aim of this study was to evaluate which factors are associated with an improvement in an HRQOL after spinal fusion surgery for nonambulatory patients with cerebral palsy (CP). METHODS A total of 157 patients with nonambulatory CP (Gross Motor Function Classification System IV and V) with a minimum of 2-year follow-up after PSF were identified from a prospective multicenter registry. Radiographs and quality of life were evaluated preoperatively and 2 years postoperatively. Quality of life was evaluated using the validated Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) questionnaire. Patients who had an increase of 10 points or greater from baseline CPCHILD scores were considered to have meaningful improvement at 2 years postoperatively. 10 points was chosen as a threshold for meaningful improvement based on differences between Gross Motor Function Classification System IV and V patients reported during the development of the CPCHILD. Perioperative demographic, clinical, and radiographic variables were analyzed to determine predicators for meaningful improvement by univariate and multivariate regression analysis. RESULTS A total of 36.3% (57/157) of the patients reported meaningful improvement in CPCHILD scores at 2 years postoperatively. Preoperative radiographic parameters, postoperative radiographic parameters, and deformity correction did not differ significantly between groups. Patients who experienced meaningful improvement from surgery had significantly lower preoperative total CHPILD scores (43.8 vs. 55.2, P

Study design Retrospective review of a multicenter, prospective database. Objective Our aim was to compare complication rates and maintenance of radiographic correction at 2 years after posterior spinal fusion (PSF) with or without cross-links in patients with cerebral palsy (CP)-related scoliosis. Summary of background data Cross-links are frequently used in PSF to correct scoliosis in patients with CP because they are thought to increase the stiffness and torsional rigidity of the construct. Methods We reviewed the records of patients with CP who underwent primary PSF with or without cross-links between August 2008 and April 2015. Inclusion criteria were minimum follow-up of 2 years, availability of complications data (implant failure, surgical site infection, revision), and pre- and postoperative measurements of the major curve (measured using the Cobb method). The 256 patients included in this analysis had a mean age of 14.1 ± 2.7 years. Ninety-four patients had cross-links (57% using one cross-link; 43% using two cross-links) and 162 patients did not have cross-links. P Results The two groups did not differ significantly with regard to sex, age at surgery, preoperative menarche status, Gross Motor Function Classification System level, major curve magnitude, pelvic obliquity, kyphosis, and lordosis angles. There were no significant differences between groups in the correction achieved or the maintenance of correction at 2 years for the major curve, pelvic obliquity, kyphosis, or lordosis (all P > 0.05). Complication rates were similar between the cross-link group (16%, N = 15) and the non-cross-link group (14%, N = 22). Conclusion At 2 years after PSF to treat CP-related scoliosis, patients had no significant differences in the degree of correction achieved, the maintenance of correction, or the rate of complications between those whose fusion constructs used cross-links and those whose constructs did not. Level of evidence 3.

Treatment outcomes and risk factors for neurological deficits in pediatric patients with an os odontoideum are unclear.We reviewed the data for 102 children with os odontoideum who were managed at 11 centers between 2000 and 2016 and had a minimum duration of follow-up of 2 years. Thirty-one children had nonoperative treatment, and 71 underwent instrumented posterior cervical spinal arthrodesis for the treatment of C1-C2 instability. Nonoperative treatment consisted of observation (n = 29) or immobilization with a cervical collar (n = 1) or halo body jacket (n = 1). Surgical treatment consisted of atlantoaxial (n = 50) or occipitocervical (n = 21) arthrodesis. One patient also underwent transoral odontoidectomy.Thirty children (29%) presented with neurological deficits, 28 of whom had radiographic atlantoaxial instability (atlantoaxial distance5 mm) or limited space (≤13 mm) available for the spinal cord (risk ratio, 7.8 [95% confidence interval, 2.0 to 31] compared with children with no radiographic risk factors). The 27 children without neurological deficits or atlantoaxial instability at presentation underwent nonoperative treatment and remained asymptomatic. Of the initial nonoperative cohort, one child developed atlantoaxial instability, and another had a persistent neurological deficit; both children underwent spinal arthrodesis during the study period. One child with cervical instability declined surgery and remained asymptomatic. Spinal fusion occurred in 68 patients in the surgical group by the end of the study period (mean, 3.7 years; range, 2.0 to 11.8 years). Surgical complications occurred in 21 children, including nonunion in 12, new neurological deficits in 4, cerebrospinal fluid leak in 2, symptomatic instrumentation requiring removal 2, and vertebral artery injury in 1. Nine children underwent revision surgery. In the surgical group, Japanese Orthopaedic Association neurological function scores improved significantly from preoperatively to the latest follow-up for the upper extremities (p = 0.026) and lower extremities (p = 0.007).The risk of developing a neurological deficit was strongly associated with atlantoaxial instability and limited space available for the spinal cord in children with os odontoideum. Nonoperative treatment was safe for asymptomatic patients without atlantoaxial instability. Spinal arthrodesis resolved the neurological deficits of children with symptomatic os odontoideum.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Prader-Willi syndrome (PWS) patients can present with scoliosis which can be treated with serial cast correction (SCC) or with growth friendly surgery (GFS). This study's purpose was to describe the results of SCC as well as GFS for PWS patients with early-onset scoliosis (EOS).PWS patients were identified from 2 international multicenter EOS databases. Scoliosis, kyphosis, spine height (T1-S1), right/left hemithoracic heights/widths (RHTH, LHTH, RHTW, LHTW) were measured pretreatment, postoperation, and at 2-year follow-up. Complications were recorded.Overall, 23 patients with 2-year follow-up were identified. Pretreatment; patients treated with SCC (n=10) had mean age of 1.8±0.6 years; body mass index (BMI), 16±1.5 kg/m; scoliosis, 45±18 degrees; kyphosis, 56±9 degrees; T1-S1, 22.4±2.4 cm; RHTH, 8.0±2.0 cm; LHTH, 8.5±1.7 cm; RHTW, 6.6±1.3 cm; and LHTW, 8.0±1.0 cm. Patients treated with GFS (n=13) had mean age of 5.8±2.6 years; BMI, 21±5.4 kg/m; scoliosis, 76±14 degrees; kyphosis, 59±25 degrees; T1-S1, 24.1±3.6 cm; RHTH, 10.0±1.6 cm; LHTH, 10.6±1.6 cm; RHTW, 9.4±2.5 cm; and LHTW, 8.1±2.8 cm. At 2-year follow-up, patients treated with SCC had mean scoliosis 37±11 degrees (18% correction, P=0.06); kyphosis, 42±6 degrees (NS); T1-S1, 26.4±2.1 cm (P0.01); RHTH, 9.0±1.1 cm (13%; P=0.30); LHTH, 10.0±1.5 cm (18%, P0.01); RHTW, 7.4±1.1 cm (12%, P0.01); and LHTW, 8.0±1.0 cm (0%, P=0.34). At 2-year follow-up, patients treated with GFS had mean scoliosis 42±13 degrees (45% correction, P0.000001); kyphosis, 53±13 degrees (10%, P=0.19); T1-S1, 31.5±5.4 cm (P0.00001); RHTH, 12.0±2.4 cm (20%; P0.01); LHTH, 12.0±1.7 cm (13%; P0.01); RHTW, 9.8±1.3 cm (4%; P=0.27); and LHTW, 7.9±2.3 cm (3%;P=0.11). As an entire group, patients with a BMI17 kg/m² had more device-related than disease-related complications (P=0.09). Patients treated with SCC had 0.9 complications per patient. Patients treated with GFS had 2.2 complications per patient [≤5 y more often had ≥2 complications (P=0.05)].At 2-year follow-up, SCC and GFS were both effective in treating EOS in PWS patients. Patients treated with SCC had significant improvements in spine height and LHTH. Patients treated with GFS had significant improvements in scoliosis magnitude, spine height, RHTH, and LHTH.Level IV-therapeutic study.

Selective fusions of the structural curve remain a common treatment strategy for adolescent idiopathic scoliosis, yet long-term outcomes are not well-understood. The purpose of this study was to report 10-year prospective radiographic and patient-rated outcomes of selective fusions of the main thoracic (MT) or thoracolumbar/lumbar (TL/L) curve, with particular attention to the behavior of the uninstrumented, compensatory curve.A prospectively collected multicenter database was used to identify patients who had been followed regularly for least 10 years after a selective MT or TL/L fusion for adolescent idiopathic scoliosis. Interval radiographs were evaluated for coronal and sagittal Cobb angles as well as overall coronal balance. Scores on the Scoliosis Research Society Questionnaire (SRS-24) were catalogued and evaluated. Radiographic outcomes and SRS-24 scores were compared between preoperative and postoperative time points using repeated-measures analysis of variance. Individual patient records were screened for recent curve progression of5°, and these cases were methodically evaluated.Fifty-one patients with selective fusions (21 MT and 30 TL/L) for adolescent idiopathic scoliosis who had been followed for at least 10 years were identified. The instrumented MT and TL/L curves were corrected by an average of 51% and 60%, respectively, at 10 years. The uninstrumented, compensatory curves had gradual spontaneous correction that approached the magnitude of the fused curve at 5 years postoperatively, with the correction maintained at 10 years. This led to excellent coronal balance. A subgroup of patients had recent progression of the primary curve adjacent to the prior fusion or within the instrumented segments, resulting in a compensatory progression of the uninstrumented curve. On the whole, SRS scores did not decrease during follow-up, and no patient had secondary operations.Selective fusion of a primary thoracic or lumbar curve in properly selected patients with adolescent idiopathic scoliosis will result in spontaneous correction of the uninstrumented curve and a durable result for at least 10 years.Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Study design A retrospective review. Objective The aim of this study was to assess correction of pelvic obliquity in children with cerebral palsy (CP) scoliosis postoperatively and 5 years after posterior spinal fusion with pelvic fixation using unit rods, sacral-alar-iliac (SAI) screws, or iliac screws. Summary of background data There are multiple options for pelvic fixation in children with scoliosis secondary to CP. The long-term differences in outcomes between these fixation methods are still unclear. Methods A multicenter review identified records of 70 children with CP who underwent posterior spinal fusion for scoliosis using unit rods (n = 9), SAI screws (n = 19), or iliac screws (n = 42). Patients younger than 18 years with 5-year follow-up were included. Pelvic obliquity and major coronal curve measurements were compared using preoperative, (first erect) postoperative, and 5-year follow-up radiographs. Implant-related complications were noted. Alpha = 0.05. Results For all groups, there was a significant difference between preoperative and postoperative pelvic obliquity that was maintained at 5 years. At 5-year follow-up, pelvic obliquity was significantly higher in the IS group (12°) compared with the unit rod group (4°, P = 0.001) and SAI screw group (6°) (P = 0.006). Implant-related complications were as follows: unit rod group, one patient (reoperation); SAI screw group, none; iliac screw group, six patients, including three cases of loss of connection between the rod and the iliac screw, two prominent screws, and one loose screw. Conclusion Correction of pelvic obliquity for children with CP-related scoliosis was achieved postoperatively using unit rods, SAI screws, and iliac screws. Implant-related complications and reoperations were most common in the iliac screw group. At 5-year follow-up, the iliac screw group had loss of major curve correction and less correction of pelvic obliquity than the unit rod and SAI screw groups. Level of evidence 3.

BACKGROUND Anterior spinal growth tethering (ASGT) has been shown to alter spinal growth with the potential to correct scoliosis while maintaining spine flexibility. The purpose of this study was to report the 2 to 4-year outcomes of ASGT in skeletally immature patients with thoracic scoliosis. METHODS We conducted a retrospective review of patients with thoracic scoliosis who underwent ASGT with a minimum of 2 years of follow-up. Patient demographics, perioperative data, and radiographic outcomes are reported. A "successful" clinical outcome was defined as a residual curve of

BACKGROUND For large scoliosis, 2 strategies to maximize correction include intraoperative traction and/or anterior release. It is unclear which patients will benefit the most form either approach. The purpose of our study is to compare the radiographic, perioperative clinical outcomes, and health-related quality of life (HRQoL) outcomes of 2 approaches when used in severe neuromuscular scoliosis in the setting of cerebral palsy (CP). METHODS In total, 23 patients with minimum 2-year follow-up, major curves ≥100 degrees, and in whom treatment included posterior spinal fusion were evaluated. Eighteen were treated with posterior spinal fusion with intraoperative traction and 5 with anterior/posterior spinal fusion (APSF). The baseline characteristics, perioperative outcomes, and preoperative and 2-year follow-up data for HRQoL and radiographic measures were compared. RESULTS The groups had similar age, sex, nutritional and seizure status, GMFCS level, and change in CPCHILD scores. The groups had similar curve magnitude (120 vs. 105 degrees, P=0.330) and flexibility (28% vs. 40%, P=0.090), but the APSF group had less pelvic obliquity (POB) (24 vs. 42 degrees, P=0.009). There were similar postoperative major curves (37 vs. 40 degrees, P=0.350), but greater correction in POB (33.5 vs. 14 degrees of correction, P=0.007) in the traction group. The APSF group had longer anesthesia times (669 vs. 415 min, P=0.005), but similar hospital stays, intensive care unit and days intubated, estimated blood loss, cell saver, and red blood cells used. Although the APSF group had twice the rate of complications (22% vs. 40%) during the first 90 days postoperatively, this did not reach statistical significance. CONCLUSIONS Both intraoperative traction and anterior surgery were used to aid correction in severe CP scoliosis. Anterior surgery did not offer superior correction or better HRQoL, and was associated with increased operative times, whereas intraoperative traction was associated with greater correction of POB. Intraoperative traction may be a viable alternative to an anterior release in severe CP scoliosis. LEVEL OF EVIDENCE Level II.

STUDY DESIGN Retrospective review of a prospective adolescent idiopathic scoliosis (AIS) registry. OBJECTIVE To study the evolution of the operative approach, outcomes, and complication rates in AIS surgery over the past 20 years. SUMMARY OF BACKGROUND DATA Surgical techniques in AIS surgery have evolved considerably over the past 20 years. We study the trends in the operative management of AIS over this period and their impact on perioperative outcomes. METHODS A total of 1819 AIS patients (1995-2013) with 2-year F/U were studied. Operative approach, perioperative parameters, major complication rates, and SRS outcomes were assessed. Linear regression was used to assess the trend of changes over 5-year quartiles. RESULTS Mean age at surgery was 14.6 ± 2.1 years, 80.2% were females, and this remained consistent throughout. Operative time, EBL/level, and LOS decreased over the 20 years (P

BACKGROUND In juveniles with progressive curves, there is debate regarding the use of growth friendly implants versus definitive fusion. This study presents outcomes of juvenile cerebral palsy (CP) scoliosis patients who underwent definitive fusion before age 11. METHODS A review of a prospective, multicenter registry identified patients 10 years and younger who had a definitive posterior fusion for their CP scoliosis. Preoperative and postoperative demographic and radiographic changes were evaluated with descriptive statistics. Repeated measures analysis of variance were utilized to compare outcome scores. RESULTS Fourteen children with a mean age of 9.7 years (8.3 to 10.8 y) and a minimum of 2 years follow-up (range 2 to 3 y) were identified. The mean preoperative curve magnitude and pelvic obliquity was 84±25 degrees (range 63 to 144 degrees) and 25±14 degrees, respectively. All patients were skeletally immature with open triradiate cartilage. Three patients had unit rods with wires while the rest incorporated pedicle screws. Immediately postoperation, the average major curve was 25±17 degrees (P≤0.001, 71% correction rate). At most recent follow-up, the average major curve increased to 30±18 degrees (P≤0.001) for a 65% correction rate. Pelvic obliquity improved to 4±4 degrees (84% correction, P≤0.001) immediately postoperation and to 6±5 degrees (P=0.002) at latest follow-up for a 76% correction rate. None of the patients required revision surgery for progression. From pre to most recent follow-up, the CPchild Health outcome scores improved from 47 to 58 (P=0.019). One patient had a deep infection, and 1 patient had a broken rod that did not require any further treatment. CONCLUSIONS Progressive scoliosis in juvenile CP patients requires the surgeon to balance the need for further growth with the risks of progression or repeated surgical procedures. Our study demonstrates that definitive fusion once the curves approach 90 degrees results in significant radiographic and quality of life improvements, but further follow-up is needed to determine whether those results remain after skeletal maturity. LEVEL OF EVIDENCE Level IV-therapeutic.

There is increasing interest in surgeon "performance measures." Understanding patient factors that increase the risk of adverse events is important for the comparison of such metrics among surgeons and centers. The purpose of this study was to ascertain whether patient characteristics, beyond the control of the surgeon, were associated with increased risk of postoperative infection following posterior spinal fusion for the correction of adolescent idiopathic scoliosis (AIS) and to establish a "risk-adjusted" method of reporting postoperative infection rates.We reviewed the data of patients from 14 participating scoliosis treatment centers who experienced an infection within 90 days following posterior spinal fusion for the treatment of AIS. Patients with a deep infection (irrigation and debridement performed) were compared with those without an infection with regard to age, sex, body mass index (BMI) percentile for age, Lenke classification of curve type, primary curve magnitude, and estimated 3-dimensional sagittal kyphosis (T5-T12). A regression model was created to identify variables that were associated with infection, and the performance of the risk model was evaluated. The actual infection rate by site was divided by the predicted infection rate for that site and multiplied by the overall rate to create a risk-adjusted rate.Of 2,122 patients analyzed, 21 (1.0%) had an infection within 90 days following surgery. Obesity was the only significant risk factor (odds ratio [OR], 7.6; p ≤ 0.001), with the resultant model demonstrating good discrimination and calibration. For the 8 sites that enrolled ≥100 patients, the predicted infection rates based on the proportion of obese patients ranged from 0.8% to 1.2%. The range of the risk-adjusted infection rates varied more substantially, from 0.2% to 2.0%.For the posterior approach to surgical correction of AIS, the only identified patient risk factor for postoperative infection was a BMI percentile for age of ≥95%. To assess infection rates, we suggest adjusting for the proportion of obese patients in the cohort. A risk-adjusted infection rate for posterior spinal fusion with instrumentation for AIS allows for more accurate assessment of performance and comparison among centers.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background Reporting accurate surgical complication rates to patients and their families is important in the management of adolescent idiopathic scoliosis (AIS). In this study, we report the rate of major complications following the surgical treatment of AIS both in the perioperative period and among patients with a minimum of 2 years of follow-up. Methods We reviewed the prospectively collected data of a multicenter registry of patients who underwent surgical treatment of AIS during the period of 1995 to 2014 in order to identify all complications. A complication was defined as "major" if it resulted in reoperation or in spinal cord or nerve root injury, or was life-threatening. A total of 3,582 patients with preoperative and early postoperative data (4 to 6 weeks of follow-up) were included. A subset of 2,220 patients with a minimum of 2 years of follow-up comprised the cohort for delayed complications. Overall complication rates were calculated, as was the percentage of complications according to the year of the index surgery and type of surgical approach. Results The mean age of the 3,582 patients at the time of surgery was 14.8 ± 2.2 years. The average major curve magnitude was 56° ± 13° for thoracic curves and 51° ± 11° for lumbar. In 365 patients, anterior spinal fusion (ASF) with instrumentation was performed, and in 3,217 patients, posterior spinal fusion (PSF) with instrumentation was performed; 142 patients in the PSF group underwent concomitant anterior release. There were 192 major complications, with 93 (2.6%) occurring perioperatively. Perioperative complications included wound-related (1.0% of the patients), neurologic (0.5%), pulmonary (0.4%), instrumentation-related (0.4%), and gastrointestinal (0.2%) complications. One patient died. The mean annual perioperative major complication rate based on the year of surgery ranged from 0% to 10.5%. The complication rate by surgical approach was 3.0% for ASF and 2.6% for PSF (2.4% for PSF only and 5.6% for PSF with anterior release). The major complication rate for the 2,220 patients with at least 2 years of follow-up was 4.1%; all but 1 had a reoperation (4.1%). The majority of these major complications were wound and instrumentation-related (1.9% and 0.8%, respectively). Conclusions After surgery for AIS, a 2.6% rate of perioperative major complications and a 4.1% rate of major complications at 2 or more years after surgery can be anticipated. The complication rate decreased over the period of study. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN An actuarial "survivorship" analysis. OBJECTIVE The aim of this study was to define the incidence and cause of surgical revision 5 years after scoliosis surgery. SUMMARY OF BACKGROUND DATA Data on contemporary revision surgery rates after idiopathic scoliosis surgery beyond the 2 years postoperatively in the adolescent and young adult population are limited. METHODS Patients enrolled in a prospective, multicenter, idiopathic scoliosis surgical registry from 1995 to 2009 were reviewed. Any spine reoperation was defined as a "terminal event." An actuarial survivorship analysis that adjusts for patients lost to follow-up was performed to determine cumulative survival. Time intervals were defined as 0 to

STUDY DESIGN Biomechanical evaluation using porcine spines. OBJECTIVE Compare the fixation strength of two currently used fusionless adolescent idiopathic scoliosis correction techniques following cyclic loading using porcine spines. SUMMARY OF BACKGROUND DATA The ability of fusionless implants to control or correct scoliosis in a growing patient requires such implants to maintain spinal fixation. Because they cross the disc, motion may weaken fixation over time. METHODS Eight pig spines were divided into cycled segments (T10-T13) and uncycled segments (T7-T8, L2-L3). Initial range of motion (ROM) was determined in torsion, flexion-extension, and lateral bending (0.5°/s to 1.75 N·m).Staple group (n = 4): 6 mm parallel staples were inserted on the right anterolateral spine across each intervertebral disc. Cycled segments received six staples (three adjacent discs) and uncycled segments received four staples (two separate discs).Tether group (n = 4): 5.35 × 35 mm right anterolateral vertebral body screws were placed into each vertebra. Cycled segments received four screws and uncycled segments received four screws. Screws in cycled segments were connected with a flexible tether tensioned to straight alignment.ROM of instrumented cycled segments was measured, and then segments were loaded to the measured ROM in flexion-extension (2000 cycles), lateral bending (1000 cycles), and axial rotation (2000 cycles). Implants were axially loaded to failure. Parametric tests compared pre- to postimplant ROM; nonparametric tests compared staple to screw pullout strength; P

STUDY DESIGN Retrospective review of prospectively collected data. OBJECTIVE To determine whether the last substantially touched vertebra (LSTV) is a valid lowest instrumented vertebra (LIV) for both Lenke 1 and 2 curve patterns with AR lumbar modifiers, and to identify preoperative risk factors of distal adding-on. SUMMARY OF BACKGROUND DATA Previous studies have recommended selecting the LSTV as the LIV for Lenke 1AR curves (main thoracic curve with A lumbar modifier and L4 tilt to the right (thoracic overhang/King type IV curve). METHODS One-hundred sixty patients with a Lenke 1 or 2 curve pattern and AR lumbar modifier who underwent posterior spinal fusion between 2008 and 2012 were reviewed. All patients had minimum 2-year follow up. Patients were identified with distal adding-on between first erect radiographs and 2-year follow up based on previously defined parameters. Factors predictive of the adding-on phenomenon were identified in a multivariate binary logistic regression model. RESULTS Twenty-seven patients (17%) were identified as having distal adding-on of their primary thoracic curve; however, only 8 of 89 patients (9%) fused to the LSTV developed adding-on (P = 0.005). Three variables were found to be significant predictors of adding-on: LIV proximal to LSTV (odds ratio, OR 3.63; P = 0.01), Risser zero (OR 4.93; P = 0.02), and C7-CSVL distance

Lateral condyle humerus fracture nonunion after surgical fixation has been reported to be1%. The purpose of this study was to evaluate the rate and risk factors for delayed healing of pediatric lateral condyle fractures after surgical fixation.Retrospective study of all operatively treated lateral condyle fractures at a single institution from 2006 to 2013 was performed. Radiographic evaluation included: measured fracture displacement at both presentation and after surgical fixation, fracture classification, and multiple parameters of pin configuration. Patients who had delayed healing were defined as those not healed by the eighth week of follow-up and were compared with those fractures that healed in8 weeks to identify risk factors associated with delayed healing. Purposeful selection was utilized to identify factors for entry into a multivariate binary logistic regression model.A total of 210 children were evaluated. Mean follow-up was 25 weeks (4 wk to 5 y). Distribution of Weiss classification was as follows: type 1, 8 (4%); type 2, 61 (29%); and type 3, 141 (67%). There were 33 (16%) delayed unions and 7 of these (3% of the entire cohort) required further surgery to achieve healing. Weiss classification, intraoperative fluoroscopy time, and intraoperative displacement after fixation met criteria for entry into the regression. While Weiss classification did not remain significant within the model, its removal resulted in a 30% change in the parameter estimate for intraoperative fluoroscopy time. For each second increase in fluoroscopy time, there is a 3% increase in the risk of delayed healing. Patients with1 mm displacement of the lateral cortex after fixation had an increased risk of delayed healing (OR=4.78, P=0.007).Delayed union of lateral condyle fractures is a matter of concern, and the rate of secondary surgery to achieve healing appears to be higher than previously reported. Risks for delayed healing include amount of residual displacement after reduction and the difficulty in attaining that reduction, as defined by fluoroscopy time.Level IV-therapeutic study, case series.

STUDY DESIGN Retrospective review of prospective data. OBJECTIVE To determine if surgically leveling the upper thoracic spine in patients with adolescent idiopathic scoliosis results in level shoulders postoperatively. SUMMARY OF BACKGROUND DATA Research has shown that preoperatively tilted proximal ribs and T1 tilt are more correlated with trapezial prominence than with clavicle angle. METHODS Prospectively collected Lenke 1 and 2 cases from a single center were reviewed. Clinical shoulder imbalance was measured from 2-year postoperative clinical photos. Lateral shoulder imbalance was assessed utilizing clavicle angle. Medial imbalance was assessed with trapezial angle (TA), and trapezial area ratio (TAR). First rib angle, T1 tilt, and upper thoracic curve were measured from 2-year radiographs. Angular measurements were considered level if ≤ 3° of zero. TAR was considered level if ≤ 1 standard deviation of the natural log of the ratio. Upper thoracic Cobb at 2-years was categorized as at or below the mean value (≤ 14°) versus above the mean. RESULTS Eighty-four patients were identified. There was no significant difference in the percentage of patients with a level clavicle angle or TAR based on first rib being level, T1 tilt being level, or upper thoracic Cobb being at/below versus above the mean (P

Review of a prospective database registry.To compare the Scoliosis Research Society (SRS)-22 and SRS-24 outcomes instruments in terms of scores, rate of ceiling effects, and discriminant ability in patients with pre- and postoperative adolescent idiopathic scoliosis.Despite improvements noted with the SRS-22, the SRS-24 is still occasionally used prospectively and for comparisons with previous studies reporting SRS-24 scores. Previous work has demonstrated that postoperative scores from the 2 versions are not interchangeable.A multicenter prospective registry of patients who underwent surgical correction of adolescent idiopathic scoliosis was queried for preoperative and 2-year postoperative SRS-22 and SRS-24 scores. Scores were compared between versions and ceiling effects were identified. Groups of deformity severity were created to evaluate discriminant ability.829 patients were identified. The SRS-22 scores for pain and general function were significantly greater than SRS-24 scores (P0.001), whereas the SRS-22 scores were significantly lower than the SRS-24 for self-image (P0.001). Preoperative ceiling effect was only noted in 1 domain each. Both versions were able to discriminate between large (80°+) and small (45°) preoperative curves in all domains and total scores (P0.05). Postoperatively, the SRS-22 scores for all shared domains and total score were significantly greater than SRS-24 scores (P0.001). Ceiling effects in 5 of 5 domain scores were noted postoperatively for SRS-22 and in 4 of 7 for SRS-24. With a smaller range of deformity postoperatively, only the SRS-22 self-image domain was able to discriminate between large (29°+) and small (≤11°) residual curves (P0.05).Scores obtained by the SRS-22 and the SRS-24 are not translatable despite shared domains. Whereas both versions demonstrated preoperative discriminant ability, postoperative discrimination of residual deformity is lacking in both. Patient-reported outcomes of treatment are crucial in advancing treatment, and improvement in the ability to assess subjective outcomes is essential.3.

Retrospective review of prospectively collected data.To compare patients with operative cerebral palsy with and without an intrathecal baclofen pump (ITB) to determine whether an ITB increases the complexity of scoliosis surgery and/or increases the risk of wound complications.Options for baclofen pump placement include before, during, or after scoliosis surgery. There is some concern that prior placement of an ITB and catheter can further complicate cerebral palsy scoliosis surgery and increase the risk for wound complications.Prospectively collected cases from a multicenter cerebral palsy scoliosis database were reviewed for patients who underwent posterior spinal instrumentation and fusion for a major coronal deformity. These patients were then divided on the basis of whether they had ITB at the time of initial scoliosis surgery. The 2 groups were compared to determine differences in demographics, operative parameters, radiographical outcomes, and rates of wound complications.Of 187 patients identified, 32 had an ITB previously placed (ITB group) and 155 did not (non-ITB group). Both groups were similar in regard to age, sex, Gross Motor Function Classification Scale score, and preoperative Cobb magnitude. When comparing operative parameters, there were no differences in the total operating room time (ITB = 375 ± 127 min, non-ITB = 423 ± 178 min; P = 0.149) or total estimated blood loss (ITB = 2323 ± 1489 mL, non-ITB = 2081 ± 1572 mL; P = 0.424). Postoperatively, the 2 groups had similar correction rates (71% vs. 67%, P = 0.303). As for perioperative wound complications, there were no differences in rates (P = 0.546) between the ITB (16%) and non-ITB group (15%).Although it may be inconvenient for the surgeon, ITBs do not increase the complexity of surgery or the risk for wound complications. When counseling patients and their caregivers on the timing of pump placement, it does not seem to compromise the care of the patient if the baclofen pump is placed first. Further study is needed to evaluate the safety of pump placement during or after scoliosis surgery.4.

Background Accurately diagnosing and treating childhood hip sepsis is challenging. Adjacent bone and soft-tissue infections are common and can lead to delayed and inappropriate treatment. This study evaluated the effect of early advanced imaging (bone scan, magnetic resonance imaging) in the management of suspected hip sepsis. Methods A retrospective review of pediatric patients admitted between 2003 and 2009 with suspected hip sepsis was performed. Patients were classified into 2 categories: group I-immediate hip aspiration or group II-advanced imaging performed before intervention. Results In total, 130 patients (53 in group I and 77 in group II) were included. No significant differences were found between the groups with regard to laboratory values, temperature, number of anesthetics, and length of hospital stay. However, patients in group I were younger than in group II (5.4 vs. 7.3 y, P=0.02) and more patients in group I were unable to bear weight on the affected limb compared with group II (83% vs. 61%, P=0.009). In group I, 36 patients (68%) had a septic hip compared with 35 patients (45%) in group II. In group I, 16 patients (30%) required reoperation versus 13 (17%) patients in group II. Results from the multivariate analysis demonstrated that reoperation was required 2.8 times (95% confidence interval, 1.12-6.78) more often in group I as compared with group II (P=0.03). Conclusions Advanced imaging performed before hip aspiration improves diagnostic efficacy and may decrease the need for reoperation. Level of evidence III.

Study design This study is a repeated measures design to measure the lumbar spine's response to common backpack loads in children with idiopathic low back pain (ILBP) using upright magnetic resonance imaging (MRI). Objective The purpose of this study is to analyze the lumbar spine's response to backpack loads with upright MRI in children with ILBP to compare their results with previously published normal child data under the same conditions. We hypothesize that typical backpack loads will have a different effect on the lumbar spine of normal children and children with ILBP. Summary of background data Research in normal children shows that backpack loads compress the lumbar intervertebral discs (IVDs), increase lumbar coronal deformity, and increase pain. Methods Fifteen pediatric and adolescent patients with ILBP were selected. Patients were excluded if a spinal deformity, an underlying pathology, or known injury was identified. A 0.6-T upright MRI scanner imaged the subjects while in supine and standing positions wearing 0-kg, 4-kg, and 8-kg backpacks. IVD height, lumbar lordosis, lumbar coronal deformity, and pain score were recorded after each condition and compared using analysis of variances. We compared the above-mentioned variables between ILBP and normal subjects using generalized least squares models. Results The cohort's mean age was 13 ± 3 years. The 4-kg and 8-kg backpacks only compressed the L5-S1 IVD relative to upright with no load. Subjects experienced increasing pain with increasing load. Load had no effect on lumbar lordosis or lumbar coronal deformity. Compared with normal children, children with ILBP experience significantly less disc compression at T12-L1 to L4-L5, less lumbar lordosis, and more pain with increasing load. Conclusion In children with ILBP, increasing backpack load compresses only the L5-S1 IVD. Compared with normal children, children with ILBP experience less lumbar IVD compression, less lumbar lordosis, and more pain due to increasing load suggesting altered mechanisms for load tolerance in children with ILBP. Level of evidence 3.

Study design Prospective cohort. Objective To (1) calculate the rate of deep wound infection in children with cerebral palsy (CP) after spinal fusion surgery; (2) identify factors (patient, laboratory, and surgical) associated with deep wound infection development; and (3) report causative organisms. Summary of background data Wound infection after spine fusion for CP is more common than after spine fusion for most other diagnoses. Methods We prospectively gathered data on 204 consecutive pediatric patients with CP who underwent surgery at 7 institutions. Univariate and multivariate regression analysis was performed to analyze patient, laboratory, and surgical characteristics to identify factors that were significantly associated with infection development. Statistical significance was set at a value of P less than 0.05. Results Deep wound infection developed in 13 (6.4%) children. The mean time to infection development was 34.2 ± 60.2 days. On univariate analysis, older age, larger curve size, presence of gastrostomy/gastrojejunostomy tube, higher preoperative serum white blood cell count, and longer operative time were significantly associated with deep wound infection. On multivariate analysis, only the presence of a gastrostomy/gastrojejunostomy tube remained significant (1.9-fold risk of deep wound infection compared with patients without tubes). Escherichia coli was the most common organism cultured from the wound sites (5 patients). Other infective agents were: Pseudomonas aeruginosa (2), methicillin-susceptible Staphylococcus aureus (1), Proteus mirabilis (1), and polymicrobial organisms (4). Conclusion Deep wound infection occurred in 6.4% of children with CP after spinal fusion. The presence of a gastrostomy/gastrojejunostomy tube was a significant predictor of infection. Gram-negative organisms were the most common causative agents. Surgeons should be cognizant of these factors when treating children with CP and may consider Gram-negative antibiotic prophylaxis.

Review of a prospective database registry of surgical patients with adolescent idiopathic scoliosis (AIS).The purpose of this study was to examine the prevalence of postoperative pain and its impact on patient-reported postoperative outcomes using the Scoliosis Research Society (SRS)-22 outcomes questionnaire.Although reportedly rare, postoperative pain can be a devastating situation for the patient with AIS. Most recent studies examining outcomes in AIS surgical treatment use the SRS Pain domain score to assess pain in this population.A prospectively enrolled multicenter database was queried. Patients with minimum 2-year follow-up and 2-year SRS scores were included. Postoperative pain after the acute phase of recovery when reported by the patient to the treating surgeon/clinical team in follow-up is recorded as a complication in the database. Patients included in this series were grouped as either reporting pain or not to the surgeon/clinical team postoperatively. Pre- and postoperative SRS scores were then compared between these 2 groups using analysis of variance (P0.05).Five hundred and eighty-four patients meeting the inclusion criteria were identified. Sixty-one (11%) reported pain at sometime between 2 weeks and 2 years postoperatively. Thirteen were within the 6-month postoperative period. Of the remaining 48 reporting pain between 6 and 24 months postoperatively, 41 (7% of the total cohort) had no obvious cause for their pain. More than half of these patients (26/41) were referred for further treatment (physical therapy, referral to pain specialist, further imaging). These 41 patients had significantly decreased 2-year SRS scores in the domains of Pain, Self-image, Mental health, and Total score (P0.05). The patients with postoperative pain were found to have significantly lower preoperative Pain domain scores (P0.001), indicative of greater pain preoperatively, yet there were no other domains effected preoperatively. For this group the pre- to postoperative SRS pain scores did not show significant change (P0.05).Unexplained pain after the 6-month postoperative period occurred in 7% of the cohort. The results indicate that patients reporting pain to their surgeons/clinical team postoperatively have lower pain scores on a subjective outcome instrument thus further validating the SRS-22 outcome tool. This reported pain seems to be associated with decreases in other SRS-22 domains. Interestingly, these patients also have lower preoperative pain scores than those without postoperative pain. Study into causes of pain in AIS and whether preoperative education and expectations targeted at this population would positively impact outcomes is warranted, especially because on average patients after AIS surgery have less pain.3.

STUDY DESIGN: A review of a multicenter, prospective registry of patients surgically treated for adolescent idiopathic scoliosis. OBJECTIVE: To investigate preoperative and postoperative distribution of coronal decompensation in Lenke 1C curves and to determine whether a selective thoracic fusion (STF) affects the results of coronal decompensation. SUMMARY OF BACKGROUND DATA: Numerous causes of postoperative coronal decompensation in Lenke 1C curves have been reported; however, there are few reports focusing on preoperative decompensation and its relation to postoperative decompensation in Lenke 1C curves. METHODS: Patients with Lenke 1C prospectively collected from a multicenter study were analyzed. Preoperatively, patients were grouped as decompensated (C7-CSVL > 2 cm) or balanced (C7-CSVL within 2 cm, where CSVL is central sacral vertical line). Preoperative distribution and factors for postoperative coronal decompensation were investigated. RESULTS: Seventy-one patients (53 STF, 18 nonselective fusions) were included. Preoperatively, coronal balance was skewed to the left (-17 ± 13 mm). Of the 21 STF decompensated to the left preoperatively, 12 (57%) remained to the left at 2 years. Postoperative thoracic correction was significantly better in those balanced postoperatively (57%) compared with those who remained decompensated (46%; P < 0.05). There were 32 STF patients who were balanced preoperatively, with 10 of these (31%) decompensated to the left at 2-year follow-up. This rate (31%) was significantly less than the group that was decompensated preoperatively (57%, P = 0.04). In the nonselective fusion group, 16 out of 18 patients (89%) were balanced at 2-year follow-up, independent of preoperative balance. CONCLUSION: Patients with Lenke 1C tended to be decompensated to the left preoperatively. In those decompensated preoperatively who underwent a STF, the majority remained greater than 2 cm to the left at 2-year follow-up. Patients with both thoracic and lumbar curves fused had better coronal balance at 2 years than selectively treated patients. Although not a contraindication to performing a selective fusion, treating surgeons should be prepared for modest coronal decompensation in 40% of patients with Lenke 1C treated with selective fusion of the thoracic curve alone. LEVEL OF EVIDENCE: 3.

A variety of radiologic screening protocols exist for evaluation of pediatric trauma patients with potential cervical spine (c-spine) injuries. The purpose of this study was to describe findings on c-spine magnetic resonance imaging (MRI) after previously normal c-spine computed tomographic (CT) scan findings at a Level 1 trauma center.A retrospective chart review of trauma patients evaluated at Rady Children's Hospital, San Diego, between January 2000 and February 2010 was conducted. Trauma patients who were younger than 18 years, placed in c-spine precautions, had a normal c-spine CT scan, who subsequently had a c-spine MRI were included. The sample was subdivided into patients who underwent CT scans between January 1, 2000 to July 31, 2005 (early group), and August 1, 2005 to February 28, 2010 (late group), to compare results between different CT scan resolutions.A total of 173 patients met inclusion criteria. With 100% of patients demonstrating normal c-spine CT scan findings, 83% of c-spine MRI findings were also negative (p0.001). Thirty patients (17%) demonstrated significant abnormalities on MRI. Of the 30, 5 (2.9%) required operative c-spine stabilization. Eighty-five patients underwent CT scan in the early group, and 88 in the late group. All 5 patients with unstable injuries not discovered on CT scan were from the early group, compared with none in the late group (p = 0.027).Our results suggest that high-resolution CT scan with sagittal and coronal reconstructions may be comparable with MRI for the detection of unstable c-spine injuries in pediatric trauma patients. Although minimizing CT scan radiation exposure remains essential, high-resolution c-spine CT scan may allow for earlier c-spine clearance with reduction of associated hard collar comorbidities in centers where MRI is not available or in situations where the patient's clinical stability precludes obtaining MRI.Diagnostic study, level III.

STUDY DESIGN: Multicenter; review of prospectively collected data. OBJECTIVE: To determine the risks and potential benefits of nonselective versus selective fusion in a matched set of patients with Lenke 5 curves. SUMMARY OF BACKGROUND DATA: The Lenke classification suggests a limited thoracolumbar/lumbar fusion for type 5 curves, although many experienced adolescent idiopathic scoliosis surgeons, at times, include a fusion of the thoracic curve. METHODS.: Prospectively collected cases from a multicenter database were analyzed. Patients with Lenke type 5 scoliosis curves were divided into 2 groups: 109 selective or short (only thoracolumbar/lumbar curve fused), and 41 nonselective or long (both thoracolumbar/lumbar and thoracic curves fused). Patients were then matched on the basis of the preoperative radiographical and clinical measures. Two-year postoperative radiographical and clinical outcomes were compared, using analysis of variance, with Bonferroni correction (P < 0.008). RESULTS: Twenty-nine matched pairs (58 patients) with Lenke 5 curves were identified. There were no preoperative differences between groups in age, thoracic or lumbar Cobb angle, curve flexibility, thoracic kyphosis, clinical trunk flexibility, or Scoliosis Research Society outcomes questionnaire scores. Postoperatively, patients in the nonselective group exhibited greater coronal correction for thoracic (residual Cobb; 22° vs. 12°) and lumbar curves (residual Cobb; 19° vs. 13°). However, the longer fusions had significantly less thoracic kyphosis (27° vs. 18°), truncal side bending (14 vs. 10 cm), and rotational flexibility (53° vs. 42°). There was no difference in clinical balance or Scoliosis Research Society questionnaire, version 22, scores. CONCLUSION: Adolescent idiopathic scoliosis surgeons attempt to achieve balanced correction with the fewest motion segments fused. Our data suggest that fusion of the thoracic curve in primary thoracolumbar scoliosis may improve coronal correction, but at the cost of decreased thoracic kyphosis and clinical flexibility 2 years postoperatively.

Study Design. Bench-top and retrospective radiographical analyses to determine apical vertebral rotation based on differential rod curvature on the postoperative lateral radiograph. Objective. To develop a clinically relevant methodology for measuring apical vertebral rotation on postoperative lateral radiographs in patients with adolescent idiopathic scoliosis, based on the distance between the spinal rods. Summary of Background Data. Traditional methods of analyzing vertebral rotation on plain radiographs are limited in the postoperative spine with segmental instrumentation. A previous methodology based on pedicle screw tip to rod distances on the posteroanterior radiograph is effective but limited by surgical technique and patient positioning relative to the x-ray beam. Methods. The trigonometric relationship between the inter-rod distances on lateral radiographs was defined and validated on a biomechanical model, with apical rotation varying from 0° to 20°. The ability to correct for malposition on the lateral radiograph was tested on 11 postoperative radiographs and correlated against corresponding postoperative computed tomographic scans. Results. The bench-top model had a strong correlation between actual apical rotation and calculated rotation for the full range of image rotations (intraclass correlation coefficient, 0.99). For the 11 clinical cases, comparisons of apical rotation measured on computed tomographic scans were highly correlated to the proposed lateral radiograph calculations (r = 0.84). Conclusion. A technique for measuring apical vertebral rotation based on the inter-rod distance on the lateral and posteroanterior radiographs was developed and validated. This technique is resilient to rotation of the patient within the x-ray machine and can complement measurement of rotation on postoperative posteroanterior radiographs.

Study design Multicenter review of prospectively collected data. Objective The purpose of this study was to evaluate the incidence of distal adding-on and associated risk factors in each of the 2 Lenke 1A curve patterns. Summary of background data Previous work has demonstrated 2 distinct Lenke 1A curve patterns on the basis of the tilt of L4 (1A-L and 1A-R) that are different in form and treatment. Methods A query of a prospective multicenter adolescent idiopathic scoliosis database identified 195 patients with Lenke 1A curves. Patients were grouped on the basis of the direction of the L4 vertebral tilt: 1A-L (left) and 1A-R (right). The incidences as well as clinical and radiographical risk factors for adding-on were identified for each group. Adding-on was defined as an increase in the Cobb angle of at least 5° and distalization of the end vertebra of the thoracic curve or a change in disc angulation of 5° or greater below the lowest instrumented vertebra from the first erect to 2-year postoperative radiographs. Results Forty (21%) patients met the criteria for adding-on. The average increase in Cobb angle was 11.9° for those categorized as having adding-on compared with 3.8° in the non-adding-on group. Lenke 1A-R curves were 2.2 times more likely to experience adding-on than 1A-L curves. In the 1A-R curves, patients who added-on were fused at an average of 1.6 levels proximal to the neutral vertebra versus an average of 0.9 levels proximal to the neutral vertebra for the patients who did not add-on (P = 0.023). Patients who added-on were fused at an average of 2.5 levels above stable versus 2.1 levels above stable in those who did not (P = 0.06). Age and skeletal maturity were not identified as risk factors in the 1A-R curves. In 1A-L curves, younger (12.7 vs. 14.7 yr, P = 0.002) and less skeletally mature patients based on Risser grading (70% vs. 14% Risser 0, P = 0.004) were more likely to experience adding-on. Conclusion Understanding the difference between Lenke 1A-L and 1A-R curve types may be helpful in preventing the adding-on phenomena postoperatively. To prevent adding-on in 1A-R curves, we recommend fusing distally to 1 level above the neutral vertebra or 1 to 2 levels above the stable vertebra. In 1A-L curves, adding-on may simply be a need to balance some lumbar curve progression in a young, skeletally immature patient.

BACKGROUND There has been an increasing trend toward referral of supracondylar humerus fractures in children to pediatric orthopaedic centers. The learning curve for treating this fracture is not well described. METHODS We retrospectively reviewed all supracondylar fractures treated by 21 pediatric orthopaedic fellows over the 2003 to 2009 academic years, with attending cases from 2005 to 2007 to serve as a control. Type IIa, IIb, and III fractures were used in the case count of for each fellows, whereas only type III fractures were used to record fluoroscopy time, operative time, and for radiographic review. Nonideal reduction was defined as a Baumann angle outside the range of 64 to 81 degrees, or an anterior humeral line that does not intersect the capitellum. RESULTS Of the 654 total operatively treated fractures, fellows treated 479 total and 213 type III fractures. Backup attendings were present in the operating room for 39% of type III fractures in the first academic quarter before falling to a baseline of 10% to 20% during the remaining quarters. Fluoroscopy time and operative time were consistent for fellows throughout the year. Nonideal reductions increased notably at case 7, correlating with increased fellow independence in the operating room, with reversal of the trend at case 15. There were no differences in complication rates and no malunions requiring osteotomy. CONCLUSIONS In order to balance training and patient care, we recommend the availability of an attending backup surgeon for the first 15 cases of supracondylar humerus fractures treated by pediatric orthopaedic fellows. LEVEL OF EVIDENCE Level III, retrospective comparative study.

Retrospective radiographic outcome analysis.To compare residual postoperative apical vertebral rotation between uniplanar versus polyaxial bilateral pedicle screw constructs in thoracic adolescent idiopathic scoliosis (AIS).Vertebral rotation is a component of the 3-dimensional deformity of AIS. The correction of vertebral rotation is an important goal of surgery. A comparison of uniplanar versus polyaxial screws has yet to be studied.A review of a multicenter database of Lenke type 1 to 3 AIS patients who underwent surgical correction of thoracic AIS by posterior segmental pedicle screw instrumentation and fusion with either uniplanar or polyaxial pedicle screws and 5.5-mm steel rod constructs was performed. Curves greater than 100 degrees were excluded to control for the propensity to use polyaxial screws to correct larger curves. Postoperative apical vertebral rotation of thoracic curves was graded as 0, 1, or 2 based on a computed tomography scan-validated radiographic method that uses the relative position of the screw tips to grade apical vertebral rotation at the 6-week and 1-year postoperative visits. By this grading method, higher grades correspond to greater residual apical vertebral rotation.Two hundred and ten patients met the inclusion criteria. The uniplanar screw group included 95 patients whereas the polyaxial screw group had 115 patients. The respective mean preoperative thoracic Cobb angle of 58±12 and 60±13 degrees (P=0.1), first erect postoperative coronal correction of 72% and 74% (P=0.38), and 1-year correction of 70% and 76% (P=0.07) were not significantly different between the uniplanar and polyaxial groups. At 6 weeks postoperation, the uniplanar group had 34% of patients with grade 0 rotation, 52% with grade 1, and only 14% with grade 2 thoracic apical vertebral rotation. In the polyaxial group, only 14% of patients were grade 0, 35% were grade 1, and 51% were the most rotated grade 2. This was a significant difference in the distribution of the axial rotation grades (P0.001), with less residual apical vertebral rotation with the use of uniplanar screws. The same pattern of results was found at 1-year postoperative evaluation (P0.001).There was little difference in the coronal plane correction of thoracic curves between the 2 types of screws. However, the uniplanar pedicle screw group had a larger proportion of patients with greater thoracic apical vertebral derotation (less residual apical vertebral rotation) compared with the polyaxial screw group. This can be attributed to the increase in rotational leverage afforded by uniplanar screws during intraoperative bilateral direct apical vertebral derotation maneuvers.

Study Design. Biomechanical study of bovine spines. Objective. The purpose of this study was to perform a biomechanical test to analyze intervertebral deflections following placement of both 1 and 2 semiconstrained TDRs in the subjacent segments of a long fusion. Summary of Background Data. Long-term sequela of long lumbar fusion for scoliosis include adjacent segment disease and flatback syndrome. Total disc replacement (TDR) is a viable option for the treatment of these conditions. Little data has been published regarding the placement of a TDR distal to a scoliosis fusion. Methods. Six thoracolumbar bovine spines (T12―S1) were instrumented from T12 to L5, with bilateral pedicle screw fixation at each level. L5―L6 and L6―S1 served as the test levels. One TDR (FlexiCore, Stryker Spine, Allendale, NJ) was initially performed adjacent to the fusion, followed by a subsequent TDR insertion at the last spinal segment. The applied load, total specimen deflection, and local transducer deflections were recorded before and after a TDR at both levels. The results were expressed as a percentage of the intact specimen. Flexion, extension, lateral bending, and torsional deflections were recorded. Results. There were no significant differences (P > 0.05) in sensor deflection observed at the L5―L6 and L6―S1 levels in the anterior and lateral transducers when compared to intact spines specimens. A similar effect was observed at the L5―L6 and L6―S1 levels in the anterior and lateral transducers when compared to intact or prior L5―L6 and intact L6―S1 constructs. Conclusion. This study has shown that using the FlexiCore system at 1 and/or 2 intervertebral disc spaces caudal to a scoliosis fusion model did not significantly change the sensor deflection at the 2 segments adjacent to a scoliosis fusion construct. Future research will continue to define the clinical setting and patients best suited for management by TDR systems.

STUDY DESIGN Retrospective study of patients enrolled in prospective randomized Food and Drug Administration trial. OBJECTIVE To evaluate the influence of pre- and postoperative disc height on postoperative motion and clinical outcomes. SUMMARY OF BACKGROUND DATA Our understanding of the factors that influence motion and ultimately patient satisfaction after lumbar disc replacement continues to evolve. METHODS Forty-two patients with a single level ProDisc-L at either the L4/5 or L5-S1 were selected. Pre- and postoperative disc height and range of motion (ROM) were measured from standing lateral and flexion-extension radiographs. Oswestry Disability Index and visual analog scale were also collected. Student t test and Spearman rho tests were performed to determine if there was any correlation or "threshold" effect between the disc height and ROM or clinical outcome. RESULTS The mean anterior and posterior disc height significantly increased from 10.8 mm to 17.6 mm and 4.4 mm to 7.9 mm, respectively (P < 0.01). The mean ROM decreased from 7.0 degrees to 5.7 degrees (P = 0.21). Patients with less than 9 mm of preoperative anterior disc height had an increase in their ROM (2.2 degrees) compared with a loss of ROM (-2.2 degrees) in patients with more than 9 mm of preoperative disc height (P = 0.02). Patients with between 16 mm and 18 mm of postoperative anterior disc height have greater ROM (7.5 degrees) than those above or below this range (3.6 degrees and 3.6 degrees respectively, P < 0.05). There was no correlation or threshold effect between clinical outcomes and disc height. CONCLUSION Patients with greater disc collapse benefit more in ROM from a total disc replacement. The optimal range to maximize ROM for postoperative anterior disc height is 16 mm to 18 mm. This optimal range did not translate into better clinical outcome at 2 years follow-up.

More than 95% of people in the United States are infected with the varicella zoster virus at some time in life, and this infection usually is manifested as chicken pox during childhood. The virus then establishes a latent infection of sensory ganglia, from which it may reactivate many years later to cause herpes zoster (shingles), a cutaneous painful rash along a dermatomal distribution. Less commonly, the varicella zoster virus may result in myotomal motor weakness or paralysis in addition to a painful dermatomal rash. A case of unilateral left C5-C6 segmental paresis attributable to herpes zoster in an otherwise healthy individual and a current review of the literature are presented. A case of zoster paresis of the shoulder muscles is presented to remind the orthopaedic community that this diagnosis may be confused with other diagnoses, including rotator cuff tear, and should be considered in the differential diagnosis of shoulder pain and shoulder girdle muscle weakness.