Aims. To determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory. Methods. Patients who underwent surgery for ASD, with a minimum of two-year follow-up, were retrospectively reviewed. In total, 210 patients were included and randomly allocated into training (70% of the sample size) and test (the remaining 30%) sets to develop the machine learning algorithm. Risk factors were included in the analysis, along with clinical characteristics and parameters acquired through diagnostic radiology. Results. Overall, 152 patients without and 58 with a history of surgical revision following surgery for ASD were observed; the mean age was 68.9 years (SD 8.7) and 66.9 years (SD 6.6), respectively. On implementing a random forest model, the classification of URO events resulted in a balanced accuracy of 86.8%. Among machine learning-extracted risk factors, URO, proximal junction failure (PJF), and postoperative distance from the posterosuperior corner of C7 and the vertical axis from the centroid of C2 (SVA) were significant upon Kaplan-Meier survival analysis. Conclusion. The major risk factors for URO following surgery for ASD, i.e. postoperative SVA and PJF, and their interactions were identified using a machine learning algorithm and game theory. Clinical benefits will depend on patient risk profiles. Cite this article: Bone Joint Res 2023;12(4):245–255

To examine the impact of a structured rehabilitation programme as part of an integrated multidisciplinary treatment algorithm for adult spinal deformity patients. A prospective cohort study was performed over a 2-year period at a major tertiary referral centre for adult spinal deformity surgery. All consecutive patients requiring 2-stage corrective surgery for sagittal malalignment were included (n=32). Details of physiotherapy initial evaluation, inpatient rehabilitation progress, details of bracing treatment and time to discharge were collected. Clinical outcome scores were measured preoperatively and at 6 weeks, 6 months and 1 year postoperatively. After second stage corrective surgery, the mean time to standing without assistance was 2.1 days, mean time to independent ambulation was 4.2 days, mean time to competent ascending and descending stairs was 5.6 days and mean time to moulded orthosis application 7.1 days. Successful progression through the structured rehabilitation programme was associated with high clinical outcome scores and improved health related quality of life (HRQOL). The introduction of this programme contributed to the development of an enhanced recovery pathway for patients having adult spinal deformity surgery, reducing inpatient length of stay and optimising clinical outcomes

Aim:. To simplify sagittal plane spinal assessment by describing a single novel angle in the lumbar spine equivalent to the difference between pelvic incidence (PI) and lumbar lordosis (LL) and evaluate its reliability. Methods:. New sagittal modifiers in the classification of adult degenerative spinal deformity have been shown to be valid and reliable with the greatest variability being for pelvic incidence minus lumbar lordosis (PI-LL). This measurement can be simplified to a new angle (alpha) without the need to determine either PI or LL. This angle is between a line intersecting the bicoxofemoral centre and perpendicular to the L1 endplate (alpha line) and a line from the bicoxofemoral centre to the centre of the sacral endplate. Two readers graded 40 non-premarked cases twice each, approximately 1 week apart. Inter- and intra-rater variability and agreement were determined for PI-LL and alpha angle separately. Fleiss' kappa was used for reliability measures. Results:. Inter-rater kappa for PI-LL showed substantial reliability and alpha angle showed almost perfect agreement. Intra-rater kappa showed substantial reliability for PI-LL but almost perfect agreement for alpha angle across both readers. Discussion:. Alpha angle can be used as a surrogate for PI-LL and is easier and more reliable to measure. When PI=LL, alpha angle is 0, so the alpha line bisects the sacral plate. Conflict Of Interest Statement: No conflict of interest

Aims. The aim of this study was to investigate the impact of the level of upper instrumented vertebra (UIV) in frail patients undergoing surgery for adult spine deformity (ASD). Methods. Patients with adult spinal deformity who had undergone T9-to-pelvis fusion were stratified using the ASD-Modified Frailty Index into not frail, frail, and severely frail categories. ASD was defined as at least one of: scoliosis ≥ 20°, sagittal vertical axis (SVA) ≥ 5 cm, or pelvic tilt ≥ 25°. Means comparisons tests were used to assess differences between both groups. Logistic regression analyses were used to analyze associations between frailty categories, UIV, and outcomes. Results. A total of 477 patients were included (mean age 60.3 years (SD 14.9), mean BMI 27.5 kg/m. 2. (SD 5.8), mean Charlson Comorbidity Index (CCI) 1.67 (SD 1.66)). Overall, 74% of patients were female (n = 353), and 49.6% of patients were not frail (237), 35.4% frail (n = 169), and 15% severely frail (n = 71). At baseline, differences in age, BMI, CCI, and deformity were significant (all p = 0.001). Overall, 15.5% of patients (n = 74) had experienced mechanical complications by two years (8.1% not frail (n = 36), 15.1% frail (n = 26), and 16.3% severely frail (n = 12); p = 0.013). Reoperations also differed between groups (20.2% (n = 48) vs 23.3% (n = 39) vs 32.6% (n = 23); p = 0.011). Controlling for osteoporosis, baseline deformity, and degree of correction (by sagittal age-adjusted score (SAAS) matching), frail and severely frail patients were more likely to experience mechanical complications if they had heart failure (odds ratio (OR) 6.6 (95% CI 1.6 to 26.7); p = 0.008), depression (OR 5.1 (95% CI 1.1 to 25.7); p = 0.048), or cancer (OR 1.5 (95% CI 1.1 to 1.4); p = 0.004). Frail and severely frail patients experienced higher rates of mechanical complication than ‘not frail’ patients at two years (19% (n = 45) vs 11.9% (n = 29); p = 0.003). When controlling for baseline deformity and degree of correction in severely frail and frail patients, severely frail patients were less likely to experience clinically relevant proximal junctional kyphosis or failure or mechanical complications by two years, if they had a more proximal UIV. Conclusion. Frail patients are at risk of a poor outcome after surgery for adult spinal deformity due to their comorbidities. Although a definitively prescriptive upper instrumented vertebra remains elusive, these patients appear to be at greater risk for a poor outcome if the upper instrumented vertebra is sited more distally. Cite this article: Bone Joint J 2024;106-B(11):1342–1347

To evaluate the differences between spinopelvic parameters before and after sagittal malalignment correction and to assess the relationship between these radiologic parameters and clinical outcome scores.

A prospective cohort study was performed over a 2-year period at a major tertiary referral centre for adult spinal deformity surgery. All consecutive patients requiring 2-stage corrective surgery were included (n=32). Radiographic parameters and clinical outcome measures were collected preoperatively and at 6 weeks, 6 months, 1 year and 2 years postoperatively. Radiographic parameters analysed included pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis and sagittal vertical axis. Clinical outcome measures collected included EQ-5D, ODI, SRS 22 and VAS Pain Scores.

Correction of sagittal malalignment was associated with significant improvements in HRQOL. Restoration of lumbar lordosis, pelvic tilt and sagittal vertical axis correlated with postoperative improvements in EQ-5D, ODI, SRS 22 and VAS Pain Scores at follow-up.

This study demonstrates that the magnitude of sagittal plane correction correlates with the degree of clinical improvements in HRQOL. This further underlines the need for spinal surgeons to target complete sagittal plane deformity correction if they wish to achieve the highest rates of HRQOL benefit in patients with marked sagittal malalignment.

Aims. Postoperative complication rates remain relatively high after adult spinal deformity (ASD) surgery. The extent to which modifiable patient-related factors influence complication rates in patients with ASD has not been effectively evaluated. The aim of this retrospective cohort study was to evaluate the association between modifiable patient-related factors and complications after corrective surgery for ASD. Methods. ASD patients with two-year data were included. Complications were categorized as follows: any complication, major, medical, surgical, major mechanical, major radiological, and reoperation. Modifiable risk factors included smoking, obesity, osteoporosis, alcohol use, depression, psychiatric diagnosis, and hypertension. Patients were stratified by the degree of baseline deformity (low degree of deformity (LowDef)/high degree of deformity (HighDef): below or above 20°) and age (Older/Younger: above or below 65 years). Complication rates were compared for modifiable risk factors in each age/deformity group, using multivariable logistic regression analysis to adjust for confounders. Results. A total of 480 ASD patients met the inclusion criteria. By two years, complication rates were 72% ≥ one complication, 28% major, 21% medical, 27% surgical, 11% major radiological, 8% major mechanical, and 22% required reoperation. Younger LowDef patients with osteoporosis were more likely to suffer either a major mechanical (odds ratio (OR) 5.9 (95% confidence interval (CI) 1.1 to 36.9); p = 0.048) or radiological complication (OR 7.0 (95% CI 1.9 to 25.9); p = 0.003). Younger HighDef patients were much more likely to develop complications if obese, especially major mechanical complications (OR 2.8 (95% CI 1.1 to 8.6); p = 0.044). Older HighDef patients developed more complications when diagnosed with depression, including major radiological complications (OR 3.5 (95% CI 1.1 to 10.6); p = 0.033). Overall, a diagnosis of depression proved to be a risk factor for the development of major radiological complications (OR 2.4 (95% CI 1.3 to 4.5); p = 0.005). Conclusion. Certain modifiable patient-related factors, especially osteoporosis, obesity, and mental health status, are associated with an increased risk of complications after surgery for spinal deformity. Surgeons should look for these conditions when assessing a patient for surgery, and optimize them to the fullest extent possible before proceeding to surgical correction so as to minimize the prospect of postoperative morbidity. Cite this article: Bone Joint J 2022;104-B(11):1249–1255

To evaluate the incidence of complications and the radiographic and clinical outcomes from 2-stage reconstruction including 3-column osteotomy for revision adult spinal deformity. A prospective cohort study performed over 2 years at a major tertiary referral centre for adult spinal deformity surgery. All consecutive patients requiring 2-stage corrective surgery for revision adult spinal deformity were included. Radiographic parameters and clinical outcome measures were collected preoperatively and at 6 weeks, 6 months, 1 year and 2 years postoperatively. Radiographic parameters analysed included pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis and sagittal vertical axis. Clinical outcome measures collected included EQ-5D, ODI, SRS 22 and VAS Pain Scores. Performing anterior column reconstruction followed by 3-column osteotomy and extension of instrumentation for revision spinal deformity resulted an excellent correction of sagittal alignment, minimal surgical complications and significant improvements in HRQOL. Restoration of lumbar lordosis, pelvic tilt and sagittal vertical axis were observed in addition to postoperative improvements in EQ-5D, ODI, SRS 22 and VAS Pain Scores at follow-up. Performing anterior column reconstruction prior to a 3-column osteotomy minimises complications associated with 3-column osteotomy and extension of posterior instrumentation. We propose a treatment algorithm for safe and effective treatment in revision adult deformity surgery

Modern techniques facilitate the treatment of adult spinal deformity. Decision making is a challenge because of potential complications relating to the surgery itself and medical problems. This study aims to provide useful data in facilitating the decision making process. Retrospective analysis of consecutive single surgeon series of patients aged >50 between 2006-2009 undergoing multi-level spinal deformity surgery with concomitant decompression. Medical co-morbidities, age and ASA were recorded. 71 patients (57 female) mean age 66 (50-83). 29 (12 multiple) failed previous stenosis surgery. 14(19.7%) in hospital complications in 11(15.5%) patients. 4 were ‘medical’. 8/11 patients were revision cases versus 3/11 primary. 4 patients (5.6%) needed further surgery. 13(18.3%) outpatient complications in 12(16.9%)patients. 7/12 occurred in revision cases versus 5/12 in primary. 11(15.5%) needed further surgery. Revisional surgery in adult deformity presents a significantly higher overall complication rate than primary surgery (p= 0.0084), but both revisional and primary cases have a relatively high re-operation rate once initially discharged. The results indicate that complex medical and surgical factors contribute to the decision making challenge in patients with adult spinal deformity and stenosis

Aim:. An analysis of significant neuromonitoring changes (NMCs) and evaluation of the efficacy of multimodality neuromonitoring in spinal deformity surgery. Method:. A retrospective review of prospectively collected data in 320 consecutive paediatric and adult spinal deformity operations. Patients were sub-grouped according to demographics (age, gender), diagnosis, radiographic findings (Cobb angles, MR abnormalities) and operative features (surgical approach, duration, levels of fixation). Post-operative neurological deficit was documented and defined as either spinal cord or nerve root deficit. Results:. 296 paediatric and adult patients were monitored in 320 consecutive spinal deformity operations between 2003 and 2013. Combined monitoring with SSEPs and MEPs was considered successful (296 of 320 operations), when it was able to produce reproducible signals with regards to SEP and / or MEP. SEP was attempted but unrecordable in 1 case, while MEPs were contraindicated in 23 cases due to epilepsy and/or medications. The overall incidence of significant NMC was 7.5% (24 NMCs out of 320 operating episodes) and overall neurological deficit was 1.6%. There were 19 true positives, 5 false positives and zero false negative results. When results were collated, the overall combined sensitivity of multimodal monitoring was 100%, specificity 98.3%, PPV 79.2% and NPV 98.3%. Discussion:. Multimodal monitoring allows accurate assessment and prevention of permanent neurological deficit that is superior to any single monitoring modality. Conflict Of Interest Statement: No conflict of interest

Aims

Symptomatic spinal stenosis is a very common problem, and decompression surgery has been shown to be superior to nonoperative treatment in selected patient groups. However, performing an instrumented fusion in addition to decompression may avoid revision and improve outcomes. The aim of the SpInOuT feasibility study was to establish whether a definitive randomized controlled trial (RCT) that accounted for the spectrum of pathology contributing to spinal stenosis, including pelvic incidence-lumbar lordosis (PI-LL) mismatch and mobile spondylolisthesis, could be conducted.

Aims

With resumption of elective spine surgery services in the UK following the first wave of the COVID-19 pandemic, we conducted a multicentre British Association of Spine Surgeons (BASS) collaborative study to examine the complications and deaths due to COVID-19 at the recovery phase of the pandemic. The aim was to analyze the safety of elective spinal surgery during the pandemic.

Aims

The direct posterior approach with subperiosteal dissection of the paraspinal muscles from the vertebrae is considered to be the standard approach for the surgical treatment of adolescent idiopathic scoliosis (AIS). We investigated whether or not a minimally-invasive surgery (MIS) technique could offer improved results.

Aims

To report the surgical outcome of patients with severe Scheuermann’s kyphosis treated using a consistent technique and perioperative management.

Aims

The aim of this study is to test the hypothesis that three grades of sagittal compensation for standing posture (normal, compensated, and decompensated) correlate with health-related quality of life measurements (HRQOL).

Aims

The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes.

Aims

Severe spinal deformity in growing patients often requires surgical management. We describe the incidence of spinal deformity surgery in a National Health Service.

Aims

The aim of this study was to determine the influence of developmental spinal stenosis (DSS) on the risk of re-operation at an adjacent level.