There is a significant positive association between hours of brace wear and rate of success in the treatment of Adolescent Idiopathic Scoliosis (AIS). The abandon rate reported in the literature averages 18%. In a recent randomized trial conducted at our center; the abandon rate was 4%. We aim to document the abandon rate towards brace treatment during the COVID-19 pandemic and its impact on AIS progression. We reviewed a database of AIS patients recruited between March and September 2020. Inclusion criteria were patients with AIS under brace treatment according to SRS criteria. The patients were divided in 2 cohorts: those with a self-reported good adherence to treatment and those who voluntarily abandoned treatment during follow-up. Patients with irregular adherence were excluded. Data analysis included age, gender, Risser stage, type of brace, Cobb angles at first visit and last follow-up (mean 11 months) and % of progression. Unpaired student tests were used for comparison. 154 patients met inclusion criteria. 20 patients were excluded due to irregular adherence. 89 patients (age: 12.1 y.o. ±1.4) reported good adherence to treatment, while 45 patients (age: 12.6 y.o. ±1.5) abandoned treatment, an abandon rate of 29%. The cohort of compliant patients started treatment with a mean main thoracic (MT) curve of 26° and finished with 27°. The mean difference between measurements was +0.65°±7.5; mean progression rate was −4.6%. However, patients who abandoned treatment started with a mean MT curve of 28° and finished with 33°, with a mean increase of +5°±8 and a mean progression rate of −11%. The differences between the 2 cohorts were statistically significant (p=0.002). Five (5) patients from the abandon group were offered for surgery because of curve progression. The abandon rate of brace treatment in AIS significantly increased during the first wave of COVID-19 pandemic. Patients who voluntarily discontinued treatment had significant increases in curve progression and surgical indication rates

Scoliosis is estimated to occur between 21–64% of patients with cerebral palsy (CP), where a subset of patients develops early onset scoliosis (EOS) before the age of ten. Traditional growth friendly (TGF) surgeries in the context of traditional growing rods have been shown to be effective in treating scoliosis in this population, however significant complication rates are reported. Currently, no studies have been done to examine the effect of novel growth friendly surgeries such as magnetically controlled growing rods (MCGR) on EOS in CP patients. The objective of this study is to compare MCGR with TGF surgeries in this patient population, specifically by evaluating radiographic measurements and risk of unplanned reoperations (UPRORs). Patients with EOS secondary to CP were prospectively identified from an international database, with data retrospectively analyzed. Scoliosis (primary curve), maximum kyphosis, T1-S1 and T1-T12 height were measured pre-operation, immediate post-operation, and at two-years follow-up. The risk and etiology of UPRORs were compared between MCGR and TGF. P < 0.05 was considered statistically significant for all analyses. Of the 120 patients that met inclusion criteria, 86 received TGF (age 7.5 ± 1.8 years; follow-up 7.0 ± 2.9 years) and 34 received MCGR (age 7.1 ± 2.2 years, follow-up 2.8 ± 0.5 years). Compared to TGF, MCGR resulted in significant improvements in maintenance of scoliosis correction (p=0.04). At final follow-up, UPRORs were 24% for MCGR (8/34 patients) and 43% (37/86 patients) for TGF (p=0.05). To minimize the influence of follow-up period, UPRORs within the first two years post-operation were evaluated: MCGR (21%, 7/34 patients) vs. TGF (14%, 12/86 patients; p=0.37). Within the first two years, etiology of UPROR as a percentage of all patients per group were deep infection (5% TGF, 6% MCGR), implant failure/migration (5% TGF, 9% MCGR), dehiscence (2% TGF, 3% MCGR), and superficial infection (1% TGF, 3% MCGR). The most common etiology of UPROR for TGF was deep infection and implant failure/migration and for MCGR was implant failure/migration. For patients with CP, at final follow-up, MCGR had superior maintenance of scoliosis correction; however, there was no difference in risk of UPROR within the first two years post-operatively (21% MCGR, 14% TGF)

To compare preoperative and postoperative Health Related Quality of Life (HRQoL) scores in operated Adolescent Idiopathic Scoliosis (AIS) patients with and without concomitant isthmic spondylolisthesis. A retrospective study of a prospective cohort of 464 individuals undergoing AIS surgery between 2008 and 2018 was performed. All patients undergoing surgery for AIS with a minimum 2-year follow-up were included. We excluded patients with prior or concomitant surgery for spondylolisthesis. HRQoL scores were measured using the SRS-22 questionnaire. Comparisons were performed between AIS patients with vs. without concomitant spondylolisthesis treated non-surgically. AIS surgery was performed for 36 patients (15.2 ±2.5 y.o) with concomitant isthmic spondylolisthesis, and 428 patients (15.5 ±2.4 y.o) without concomitant spondylolisthesis. The two groups were similar in terms of age, sex, preoperative and postoperative Cobb angles. Preoperative and postoperative HRQoL scores were similar between the two groups. HRQoL improved significantly for all domains in both groups, except for pain in patients with spondylolisthesis. There was no need for surgical treatment of the spondylolisthesis and no slip progression during the follow-up duration after AIS surgery. Patients undergoing surgical treatment of AIS with non-surgical management of a concomitant isthmic spondylolisthesis can expect improvement in HRQoL scores, similar to that observed in patients without concomitant spondylolisthesis

Proximal junctional kyphosis (PJK) is defined as adjacent segment kyphosis >10° between the upper instrumented vertebrae and the vertebrae 2 levels above following scoliosis surgery. There are few studies investigating the predictors and clinical sequelae involved with this relatively common complication. Our purpose was to determine the radiographic predictors of post-op PJK and to examine the association between PJK and pain/HRQOL following surgery for AIS. The Post-Operative Recovery after Scoliosis Correction: Home Experience (PORSCHE) study was a prospective multicenter cohort of AIS patients undergoing spinal fusion surgery. Pre-op and minimum 2 year f/u scoliosis and sagittal spinopelvic parameters (thoracic kyphosis–TK, lordosis–LL, pelvic tilt-PT, sacral slope-SS, pelvic incidence-PI) were measured and compared to numeric rating scale for pain (NRS) score, SRS-30 HRQOL and to the presence or absence of PJK (proximal junctional angle >100). Continuous and categorical variables were assessed using logistic regression and binomial variables were compared to binomial outcomes using chi-square. 163 (137 females) patients from 8 Canadian centers met inclusion criteria. At final f/u, PJK was present in 27 patients (17%). Pre-op means for PJK vs No PJK: Age 14.1 vs 14.7yr; females 85 vs 86%; scoliosis 57±22 vs 62±15deg; TK 28±18 vs 19±16deg ∗, LL 62±11 vs 60±12deg, PT 8±12 vs 10±10deg, SS 39±8 vs 41±9deg, PI 47±14 vs 52±13deg, SVA −9±30 vs −7±31mm. Final f/u for PJK vs No PJK: Scoliosis 20±11 vs 18±8deg, final TK 26±12 vs 19±10deg∗, LL 60±11 vs 57±12deg, PT 9±12 vs 12±13deg, SS 39±9 vs 41±9deg, PI 48±17 vs 52±14deg, SVA −23±26 vs −9±32mm∗. Significant findings: Pre-op kyphosis >40deg has an odds ratio (OR) of 4.41 (1.50–12.92) for developing PJK∗. The presence of PJK was not associated with any significant differences in NRS or SRS-30. ∗denotes p<0.05. This prospective multicenter cohort of AIS patients demonstrated a 17% risk of developing PJK. Pre-op thoracic kyphosis >40deg was associated with the development of PJK; however, the presence of PJK was not associated with increased pain or decreased HRQOL

Purpose of the study. The aim of the study was to review the surgical management of Neuromuscular Scoliosis (NMS) and its outcome. Method. NMS patients who underwent surgery between 2001 and 2012 were identified. Case notes, surgical data, complications and radiographic results were reviewed retrospectively. The families were contacted telephonically. Sitting posture status and whether the parents and patients would opt to have the surgery again if given the opportunity, was assessed. Summary of Results. 96 NMS patients had corrective spinal surgery performed by a single surgeon in 4 institutions. Cerebral Palsy was the most common underlying cause (18) followed by Myelomeningocoele (15), SMA (12) and post spinal cord injury scoliosis (10). 52 patients were female and 44 male with a median age of 13.6 years at surgery. The delay to surgery after presentation was 20.6 months. Seventy patients received posterior only based surgery and 12 patients had anterior only fusions. Another 12 patients had a 2-stage procedure with a delay of 12 days between operations. The average blood loss was 1600ml and duration of surgery 222 minutes. Forty seven patients had pedicle screw only constructs and 46 patients' constructs included the pelvis. An average of 14.2 levels were included in the construct. The primary curve was corrected from 84.4° to 32.7° which was mostly maintained throughout the follow-up period. 55 patients had a follow-up of greater or equal to 2 years. Only one patient reported not having improved his sitting posture. 3 parents and 5 patients would opt not to have the surgery again. Conclusion. Spine fusion in NMS is effective in correcting and maintaining correction of associated scoliosis despite the risk of major complications. Most patients and family value the clinical improvement and would agree to surgery again. NO DISCLOSURES

To evaluate the efficacy of VEPTR in preventing further progression of scoliosis without impeding spinal growth in the treatment of children with progressive early onset scoliosis (EOS) without rib abnormalities. Prospective, multi-center, observational cohort study on patients with EOS treated with VEPTR with 2-year follow up. Data were analysed based on measurements done pre-implant, immediate post-op and at 2-yr f/u. Sixty-three patients met inclusion: 35 males and 28 females. Mean age at time of implantation was 6.1±2.4 yrs. Etiologies included congenital (n=6), neuromuscular (n=36), syndromic (n=4), and idiopathic (n=17). Mean follow up was 2.2±0.4 yrs. Scoliosis (72o±18o) decreased after implant surgery (47o±17o) followed by slight increase at 2-yr f/u (57o±18o), p<0.0001. At 2-yr f/u, VEPTR was effective in treating EOS without rib abnormalities with 86% of patients having an improvement in scoliosis and 94% of patients having an increased spinal height as compared to pre-operatively. VEPTR provided greater than 100% of expected age-matched spine growth and the instrumented spinal segment continued to grow during distraction phase. This large prospective, multicentre study demonstrated the ability of VEPTER to effectively treat EOS without rib abnormalities. Goals of preventing further scoliosis progression and of maintaining normal spine growth were achieved

Orthopaedic paediatric deformities, globally, are often corrected later than initial identification due to resource constraints (bed availability, investigative modalities, surgical skill set). The study aims to analyse experiences and challenges met with running a flagship scoliosis surgery week in a tertiary public health care facility, with the goal of reducing patient waiting time on the waiting list.

In this retrospective study, patients from an existing deformity correction waiting list were selected for a 5 day scoliosis surgery week. Investigations relevant to clinical findings were carried out and patients were scheduled on a “one patient per day” surgery list. Inclusion criteria was any patient with adolescent idiopathic scoliosis of varying degree that was symptomatic. Exclusion criteria was any other deformity of any age.

Outcomes measured include: Administrative hurdles (obtaining funding, organising ward and ICU beds, getting nursing staff), Surgical challenges (severity of the curve, intraoperative time, approach chosen) and perioperative management (anaesthesia, pain management, cost of equipment) will be looked at to better define the experiences and challenges.

All scheduled surgeries were completed. This meant more cases were carried out than what was done in the last 2 years at the facility combined. Lack of Nursing staff availability and few ICU beds delayed starting cases. Anterior fusion took a shorter surgical time in comparison to posterior and cost far less to carry out owing to deformity severity. Intra and post operative management also varied due to daily changes in theatre staff and a lack of standardized protocols.

Running a scoliosis surgery week helps to lower the waiting time for deformity correction in public health care facilities. Pre organising resources results in more successful outcomes and an increase in the number of cases done over a shorter period.

Purpose. Spinopelvic parameters describe the orientation, shape, and morphology of the spine and pelvis. In children without spinal deformity, these parameters have been shown to change during the first ten years of life; however, spinopelvic parameters have yet to be defined in children with significant Early Onset Scoliosis (EOS). The purpose of this study is to examine the effects of EOS on sagittal spinopelvic alignment. Method. Standing, lateral radiographs of 82 untreated patients with EOS greater than 50 degrees were evaluated. Sagittal spine parameters (sagittal balance, thoracic kyphosis (TK), lumbar lordosis (LL)) and sagittal pelvic parameters (pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), modified pelvic radius angle (PR)) were measured. These results were compared to those reported by Mac-Thiong et al (Spine, 2004) for a group of asymptomatic (i.e. without spinal deformity) children of similar age. Results. These patients had a mean age of 5.17 years and mean scoliosis of 73.3 17.3. Mean sagittal spine parameters were: sagittal balance (+2.4 4.03 cm), TK (38.2 20.8), and LL (47.8 17.7). These values were similar to those reported for asymptomatic subjects. Mean sagittal pelvic parameters were measured for PI (47.1 15.6), PT (10.3 10.7), SS (35.5 12.2), and PR (57.1 21.2). Although PI was similar to age-matched normals, PT was significantly higher and SS trended lower in the study population. Conclusion. Sagittal plane spine parameters in children with EOS were similar to those found in children without spinal deformity. Likewise, pelvic parameters (PI, SS, PR) were similar; however, those children with EOS signs of pelvic retroversion (increased pelvic tilt). This data may be useful as a baseline in determining prognosis for children with EOS who are treated with growing systems

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine characterized by a Cobb angle of at least 10 degrees. The goal of surgery is to not only prevent progression but restore sagittal and coronal balance, protecting cardiopulmonary function and improving cosmesis.

We reviewed the impact of deformity correction surgery in terms of radiology and patient reported outcome(PROMs).

The senior authors prospectively maintained database from 2003 –2022 was retrospectively analysed in terms of pre- and post-operative patient reported outcome measures (SRS 22) as well as radiological parameters.

44 patients with AIS were identified with pre and post op PROMS. The average age at surgery was 15yrs with 84% female. 38% had a Lenke 1 curve and 3 patients had Lenke 6 curves. 73% had posterior surgery.

There was a total improvement in SRS 22 scores by 7.8%. Patients reported significant satisfaction with treatment 4.8/5 and improvement in self-image with a change of 0.4 (p<0.001). However, no difference in function, pain and mental health were recorded.

Overall, proximal thoracic (PT) curves improved from 24 degrees to 11 degrees (p<0.001), Main thoracic (MT) curve 55 degrees to 19 degrees and Thoracolumbar/Lumbar curves (TL/L) 45 degreesto 11 degrees. Pre-operative flexibility and post-operative correction were 0.40 and 0.41 respectively for PT curve. MT was 0.32 and 0.67. That for TL/L was 0.57 and 0.71 respectively.

Surgery yields significant main curve correction correlating with high patient reported satisfaction rate. Although total SRS 22 score yielded 7.8% improvement, sub-analysis of self-image showed the most significant improvement.

Adolescent idiopathic scoliosis is a three-dimensional deformity of the spine, affecting 1–3% of the population.

Most cases are treated conservatively. Curves exceeding 45° in the thoracic spine and 40° in the lumbar spine may require correction and fusion surgery, to limit the progression of the curve and prevent restrictive pulmonary insufficiency (curves above 70°). When fusion is required, it may be performed either by posterior or anterior approaches. Posterior is useful for thoracic (Lenke I) curves, notably to correct the thoracic hypokyphosis frequently observed in AIS. Anterior approaches by thoraco-lombotomies allow an effective correction of thoraco-lumbar and lumbar curves (Lenke V and VI), with fewer levels fused than with posterior approaches. However, the approach requires diaphragm splitting and one may be concerned about the long-term pulmonary consequences. The literature provides conflicting insight regarding the consequences of the approach in anterior scoliosis correction, the interpretation of the results being difficult knowing that the correction of the scoliosis itself may improve pulmonary function.

This is a retrospective observational study done at a Tertiary Institution. The HRQOL scores have been collected as a prospective cohort. Clinical and radiographic data was collected from patients charts and analysed by two senior surgeons

A cohort of 64 patients were operated in the given time period. 50 patients met the inclusion criteria. No major complications were reported. The Union rate was 100% and no post operative complications were noted. Pre and post SRS scores improved in all patients.

The Anterior approach for Lenke V AIS gives great surgical exposure and allows for excellent correction of Cobb angle with minimal risk to the patient.

The routine use of intraoperative vancomycin powder to prevent postoperative wound infections has not been borne out in the literature in the pediatric spine population. The goal of this study is to determine the impact of vancomycin powder on postoperative wound infection rates and determine its potential impact on microbiology.

A retrospective analysis of the Harms Study Group database of 1269 adolescent idiopathic scoliosis patients was performed. Patients that underwent a posterior fusion from 2004-2018 were analyzed. A comparative analysis of postoperative infection rates was done between patients that received vancomycin powder to those who did not. Statistical significance was determined using Chi-squared test. Additionally, the microbiology of infected patients was examined.

In total, 765 patients in the vancomycin group (VG) were compared to 504 patients in the non-vancomycin group (NVG). NVG had a significantly higher rate of deep wound infection (p<0.0001) and associated reoperation rate compared to VG (p<0.0001). Both groups were compared for age, gender, race, weight, surgical time, blood loss, number of levels instrumented, and preop curve magnitude. There were significant differences between the groups for race (p<0.0001); surgical time (p=0.0033), and blood loss (p=0.0021). In terms of microbiology, VG grew p.acnes (n=2), and serratia (n=1), whereas NVG grew p.acnes (n=1) and gram positive bacilli (n=1). The remaining cultures were negative.

The use of intraoperative vancomycin powder in adolescent idiopathic scoliosis appears to contribute significantly to deep wound infection prevention and reduction of associated reoperations. Based on this study's limited culture data, Vancomycin does not seem to alter the microbiology of deep wound infections.

Introduction. Radiographic parameters have been shown to have a poor correlation with clinical outcome after open scoliosis procedures. However this has not been previously addressed after endoscopic surgery. The purpose of our study was to examine prospectively the relationship between curve correction and clinical outcome for endoscopic scoliosis surgery. Methods. We studied 50 consecutive patients who underwent endoscopic instrumentation, with a minimum follow-up of two years. All patients were assessed pre-operatively and at 24 months post-operatively. Radiological parameters were measured from plain standing radiographs including the coronal Cobb angle, sagittal alignment, coronal alignment and shoulder elevation. Clinical outcome was assessed using the Scoliosis Research Society Outcomes Instrument (SRS-24). Correlation between radiological parameters and SRS-24 scores were determined using the Pearson correlation coefficient. Results. There were 45 females and 5 males with a mean age of 16.4 years (range, 10 to 46). The pre-operative coronal Cobb angle was mean 51.7 ± 8.5 and the post-operative instrumented Cobb angle was mean 20.4 ± 7.8 corresponding to a mean curve correction of 60.7%. There was a positive correlation between instrumented Cobb angle and total SRS-24 score (p=0.03, r2=0.085) and between curve correction and total SRS-24 score (p=0.04, r2=0.081). No correlation was found between coronal alignment, sagittal alignment, shoulder elevation or size of rib hump and the SRS-24 scores (p>0.05). Conclusions. Overall endoscopic scoliosis surgery was associated with a good clinical outcome for our series of patients. Using a validated assessment instrument, clinical outcome correlated well with the amount of curve correction achieved

Abstract

In the pediatric population, scoliosis is classified into congenital, syndromic, idiopathic, and neuromuscular in aetiology. Syndromic scoliosis represents a wide range of systemic anomalies associated with scoliosis. The primary challenge for a clinician is to think beyond the scoliotic curve, as the underlying pathology is multisystemic. The aim of this review is to identify the systemic anomalies, associated with syndromic scoliosis.

MEDLINE, EMBASE, and CINAHL databases were searched, dating from 1990–2020, relevant to the purpose of our study. Keywords used: “scoliosis”+ “syndrome” + “genetic”. Retrospective, prospective studies were included. Case reports that had fewer than 4 patients were not included.

Delineating 60 articles, we found a total of 41 syndromes to be associated with scoliosis. Thoracic region was the most common level of scoliosis curve, being noted in 28 syndromes. Mental retardation, seizures, and ataxia were the commonly noticed CNS anomalies. VSD, ASD, and TGA were the anomalies associated with CVS; Hypotonia, rib and vertebral malformations were the most identified neuromuscular anomalies; pulmonary hypoplasia, renal agenesis, and strabismus were other associations.

A multidisciplinary approach, involving spinal surgeons, paediatricians, geneticists, anesthesiologists, and allied health professionals, is vital for the best care of patients with syndromic scoliosis.

The location of the scoliotic curve reflects the associated anomalies, as thoracic curvature is more closely linked with cardiac anomalies, while lumbosacral curvature is seen to be often linked with genitourinary anomalies. We hope that this article provides a clear overview of the systemic associations in syndromic scoliosis and thus, facilitates and streamlines the management protocol.

This study aimed to identify factors associated with increased rates of blood transfusion in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF).

A retrospective case-control study was performed for AIS patients treated at a large children's hospital between August 2018 and December 2020. All patients with a diagnosis of AIS were evaluated. Data on patient demographics, AIS, and transfusion parameters were collected. Univariate regression and multivariate logistic modeling were utilized to assess risk factors associated with requiring transfusion. Odds ratios (OR) and 95% confidence interval (CI) were calculated. Surgeries were done by three surgeons and thirty anesthesiologists. To quantify the influence of anesthesia practice preferences a categorical variable was defined as “higher-transfusion practice preference”, for the provider with the highest rate of transfusion.

A total of 157 AIS patients were included, of whom 56 were transfused RBC units (cases), and 101 did not receive any RBC transfusion (controls). On univariate analysis, the following variables were significantly correlated with receiving RBC transfusion: “higher-transfusion practice preference,” “administration of crystalloids,” “receiving fresh frozen plasma (FFP),” “receiving platelets,” “pre-operative hemoglobin,” “cell saver volume,” and “surgical time.” On multiple regression modeling, “pre-operative hemoglobin less than 120 g/L” (OR 14.05, 95% CI: 1.951 to 135.7) and “higher-transfusion practice preference” (OR 11.84, 95% CI: 2.505 to 63.65) were found to be meaningfully and significantly predictive of RBC transfusion.

In this cohort, we identified pre-operative hemoglobin of 120 g/L as a critical threshold for requiring transfusion. In addition, we identified significant contribution from anesthesia transfusion practice preferences. Our multivariate model indicated that these two factors are the major significant contributors to allogenic blood transfusion. Although further studies are required to better understand factors contributing to transfusion in AIS patients, we suggest standardized, peri-operative evidence-based strategies to potentially help reduce variations due to individual provider preferences.

Prior to the introduction of steroid management in Duchenne Muscular Dystrophy (DMD), the prevalence of scoliosis approached 100%, concomitant with progressive decreases in pulmonary function. As such, early scoliosis correction (at 20-25°) was advocated, prior to substantial pulmonary function decline. With improved pulmonary function and delayed curve progression with steroid treatment, the role of early surgery has been questioned. The purpose of this study was to compare the post-operative outcomes of early versus late scoliosis correction in DMD. We hypothesize that performing later surgery with larger curves would not lead to worse post-operative complications.

Retrospective cohort study. Patients with DMD who underwent posterior scoliosis correction, had pre-operative pulmonary function testing, and at least 1-year post-operative follow-up, were included; divided into 2 Groups by pre-operative curve angle – 1: ≤45°, 2: >45°. Primary outcome was post-operative complications by Clavien-Dindo (CD) grading. Secondary outcomes included: age at surgery, forced vital capacity (FVC), steroid utilization, fractional shortening (FS) by echocardiogram, surgery duration, blood transfusion requirements, ICU length of stay (LOS), days intubated post-operatively, hospital LOS, infection, curve correction. Two-tailed t-test and chi-square testing were used for analysis of patient factors and CD complication grade, respectively.

31 patients met the inclusion criteria, with a mean total follow-up of 8.3±3.2 years. Steroid treatment (prednisone, deflazacort) was utilized for 21 (67.7%) patients, for a mean duration of 8.2±4.0 years. Groups were comparable for steroid use, FVC, echo FS, and age at surgery (p>0.05). Primary curve angle was 31.7±10.4° and 58.3±11.1° for Groups 1 and 2, respectively (p 0.05). Surgery duration, ICU LOS, days intubated, hospital LOS, were also not different between Groups. For the entire cohort, however, the overall complication rate was higher for patients with steroid treatment [61.9% vs 10%, respectively (p=0.008)], the majority being CDII. Neither FVC nor echo FS were different between Groups at final follow-up (p=0.6; p=0.4, respectively).

Post-operative complication rates were not different for early and late scoliosis correction in DMD. In general, however, patients undergoing steroid treatment were at higher risk of blood transfusion and deep infection. Delaying scoliosis correction in DMD while PF is favourable is reasonable, but patients with prior steroid treatment should be counseled regarding the higher risk of complications.

The purpose of this study is to evaluate risk factors for distal construct failure (DCF) in posterior spinal instrumented fusion (PSIF) in adolescent idiopathic scoliosis (AIS). We observed an increased rate of DCF when the pedicle screw in the lowest instrumented vertebra (LIV) was not parallel to the superior endplate of the LIV, however this has not been well studied in the literature. We hypothesise a more inferiorly angled LIV screw predisposes to failure and aim to find the critical angle that predisposes to failure.

A retrospective cohort study was performed on all patients who underwent PSIF for AIS at the Starship Hospital spine unit from 2010 to 2020. On a lateral radiograph, the angle between the superior endplate of the LIV was measured against its pedicle screw trajectory. Data on demographics, Cobb angle, Lenke classification, instrumentation density, rod protrusion from the most inferior screw, implants and reasons for revision were collected.

Of 256 patients, 10.9% (28) required at least one revision. The rate of DCF was 4.6% of all cases (12 of 260) and 25.7% of revisions were due to DCF. The mean trajectory angle of DCF patients compared to all others was 13.3° (95%CI 9.2° to 17.4°) vs 7.6° (7° to 8.2°), p=0.0002. The critical angle established is 11°, p=0.0076. Lenke 5 and C curves, lower preoperative Cobb angle, titanium only rod constructs and one surgeon had higher failure rates than their counterparts. 9.6% of rods protruding less than 3mm from its distal screw disengaged.

We conclude excessive inferior trajectory of the LIV screw increases the rate of DCF and a screw trajectory greater than 11° predisposes to failure. This is one factor that can be controlled by the surgeon intraoperatively and by avoiding malposition of the LIV screw, a quarter of revisions can potentially be eliminated.

7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.

Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-years follow-up. Demographic data, instrumented levels and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage and pain levels were evaluated.

Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1–2 and four Lenke 3–6. Five patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for two LIV was distal to the LTV; for two, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.

The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis

Our prospective observational study of patients treated for Thoracolumbar Adolescent Idiopathic Scoliosis (AIS) by anterior instrumentation aimed at investigating the correlation between the radiographic outcome and the recently-developed scoliosis research society self-reported outcomes instrument (SRS-22) which has been validated as a tool for self-assessment in scoliosis patients. Previous patient based questionnaires demonstrated poor correlation with the radiological parameters. Materials and Methods. Pre-operative, post-operative and two years follow-up radiographs of 30 patients were assessed. Thirteen radiographic parameters including Cobb angles and balance were recorded. The percentage improvements for each were noted. The SRS-22 questionnaire was completed by all patients at final follow-up. Correlation was sought between each radiographic parameter, total SRS score and each of the five domains by quantifying Pearson's Correlation Coefficient (r). Results. Percentage improvement in primary Cobb angle (r = 0.052), secondary Cobb angle (r = 0.165), apical vertebra translation of the primary curve (r = -0.353), thoracic kyphosis (r = 0.043) and lumbar lordosis (r = 0.147) showed little or no correlation with the SRS-22 total score and its five individual domains. Significant inverse correlation was found between the upper instrumented vertebra angle and at follow-up and SRS-22 (r = -0.516). The same was true for Sagittal plumb line shift at final follow up (r = -0.447). Conclusion. SRS-22 is a validated tool for the self-assessment of health status in spinal deformity patients; however, it does not seem to correlate with most of the radiographic parameters commonly used by clinicians to assess patient outcome with the exception of upper instrumented vertebra angle and sagittal plumb line which do correlate significantly with the SRS-22 outcomes instrument. A comprehensive system of assessing the success of surgery both from the patient and clinicians perspective is required in the spinal deformity patient

Abstract

Neuromuscular scoliosis patients face rates of major complications of up to 49%. Along with pre-operative risk reduction strategies (including nutritional and bone health optimization), intra-operative strategies to decrease blood loss and decrease surgical time may help mitigate these risks. A major contributor to blood loss and surgical time is the insertion of instrumentation which is challenging in neuromuscular patient given their abnormal vertebral and pelvic anatomy. Standard pre-operative radiographs provide minimal information regarding pedicle diameter, length, blocks to pedicle entry (e.g. iliac crest overhang), or iliac crest orientation. To minimize blood loss and surgical time, we developed an “ultra-low dose” CT protocol without sedation for neuromuscular patients.

Our prospective quality improvement study aimed to determine: if ultra-low dose CT without sedation was feasible given the movement disorders in this population; what the radiation exposure was compared to standard pre-operative imaging; whether the images allowed accurate assessment of the anatomy and intra-operative navigation given the ultra-low dose and potential movement during the scan.

Fifteen non-ambulatory surgical patients with neuromuscular scoliosis received the standard spine XR and an ultra-low dose CT scan. Charts were reviewed for etiology of neuromuscular scoliosis and medical co-morbidities. The CT protocol was a high-speed, high-pitch, tube-current modulated acquisition at a fixed tube voltage. Adaptive statistical iterative reconstruction was applied to soft-tissue and bone kernels to mitigate noise. Radiation dose was quantified using reported dose indices (computed tomography dose index (CTDIvol) and dose-length product (DLP)) and effective dose (E), calculated through Monte-Carlo simulation. Statistical analysis was completed using a paired student's T-test (α = 0.05). CT image quality was assessed for its use in preoperative planning and intraoperative navigation using 7D Surgical System Spine Module (7D Surgical, Toronto, Canada).

Eight males and seven females were included in the study. Their average age (14±2 years old), preoperative Cobb angle (95±21 degrees), and kyphosis (60±18 degrees) were recorded. One patient was unable to undergo the ultra-low dose CT protocol without sedation due to a co-diagnosis of severe autism. The average XR radiation dose was 0.5±0.3 mSv. Variability in radiographic dose was due to a wide range in patient size, positioning (supine, sitting), number of views, imaging technique and body habitus. Associated CT radiation metrics were CTDIvol = 0.46±0.14 mGy, DLP = 26.2±8.1 mGy.cm and E = 0.6±0.2 mSv. CT radiation variability was due to body habitus and arm orientation. The radiation dose differences between radiographic and CT imaging were not statistically significant. All CT scans had adequate quality for preoperative assessment of pedicle diameter and orientation, obstacles impeding pedicle entry, S2-Alar screw orientation, and intra-operative navigation.

“Ultra-low dose” CT scans without sedation were feasible in paediatric patients with neuromuscular scoliosis. The effective dose was similar between the standard preoperative spinal XR and “ultra-low dose” CT scans. The “ultra-low dose” CT scan allowed accurate assessment of the anatomy, aided in pre-operative planning, and allowed intra-operative navigation despite the movement disorders in this patient population.