Development and validation of AI-based automatic measurement of coronal Cobb angles in degenerative scoliosis using sagittal lumbar MRI.

OBJECTIVES: Severity of degenerative scoliosis (DS) is assessed by measuring the Cobb angle on anteroposterior radiographs. However, MRI images are often available to study the degenerative spine. This retrospective study aims to develop and evaluate the reliability of a novel automatic method that measures coronal Cobb angles on lumbar MRI in DS patients. MATERIALS AND METHODS: Vertebrae and intervertebral discs were automatically segmented using a 3D AI algorithm, trained on 447 lumbar MRI series. The segmentations were used to calculate all possible angles between the vertebral endplates, with the largest being the Cobb angle. The results were validated with 50 high-resolution sagittal lumbar MRI scans of DS patients, in which three experienced readers measured the Cobb angle. Reliability was determined using the intraclass correlation coefficient (ICC). RESULTS: The ICCs between the readers ranged from 0.90 (95% CI 0.83-0.94) to 0.93 (95% CI 0.88-0.96). The ICC between the maximum angle found by the algorithm and the average manually measured Cobb angles was 0.83 (95% CI 0.71-0.90). In 9 out of the 50 cases (18%), all readers agreed on both vertebral levels for Cobb angle measurement. When using the algorithm to extract the angles at the vertebral levels chosen by the readers, the ICCs ranged from 0.92 (95% CI 0.87-0.96) to 0.97 (95% CI 0.94-0.98). CONCLUSION: The Cobb angle can be accurately measured on MRI using the newly developed algorithm in patients with DS. The readers failed to consistently choose the same vertebral level for Cobb angle measurement, whereas the automatic approach ensures the maximum angle is consistently measured. CLINICAL RELEVANCE STATEMENT: Our AI-based algorithm offers reliable Cobb angle measurement on routine MRI for degenerative scoliosis patients, potentially reducing the reliance on conventional radiographs, ensuring consistent assessments, and therefore improving patient care. KEY POINTS: • While often available, MRI images are rarely utilized to determine the severity of degenerative scoliosis. • The presented MRI Cobb angle algorithm is more reliable than humans in patients with degenerative scoliosis. • Radiographic imaging for Cobb angle measurements is mitigated when lumbar MRI images are available.

AI-based lumbar central canal stenosis classification on sagittal MR images is comparable to experienced radiologists using axial images.

OBJECTIVES: The assessment of lumbar central canal stenosis (LCCS) is crucial for diagnosing and planning treatment for patients with low back pain and neurogenic pain. However, manual assessment methods are time-consuming, variable, and require axial MRIs. The aim of this study is to develop and validate an AI-based model that automatically classifies LCCS using sagittal T2-weighted MRIs. METHODS: A pre-existing 3D AI algorithm was utilized to segment the spinal canal and intervertebral discs (IVDs), enabling quantitative measurements at each IVD level. Four musculoskeletal radiologists graded 683 IVD levels from 186 LCCS patients using the 4-class Lee grading system. A second consensus reading was conducted by readers 1 and 2, which, along with automatic measurements, formed the training dataset for a multiclass (grade 0-3) and binary (grade 0-1 vs. 2-3) random forest classifier with tenfold cross-validation. RESULTS: The multiclass model achieved a Cohen's weighted kappa of 0.86 (95% CI: 0.82-0.90), comparable to readers 3 and 4 with 0.85 (95% CI: 0.80-0.89) and 0.73 (95% CI: 0.68-0.79) respectively. The binary model demonstrated an AUC of 0.98 (95% CI: 0.97-0.99), sensitivity of 93% (95% CI: 91-96%), and specificity of 91% (95% CI: 87-95%). In comparison, readers 3 and 4 achieved a specificity of 98 and 99% and sensitivity of 74 and 54%, respectively. CONCLUSION: Both the multiclass and binary models, while only using sagittal MR images, perform on par with experienced radiologists who also had access to axial sequences. This underscores the potential of this novel algorithm in enhancing diagnostic accuracy and efficiency in medical imaging. KEY POINTS: Question How can the classification of lumbar central canal stenosis (LCCS) be made more efficient? Findings Multiclass and binary AI models, using only sagittal MR images, performed on par with experienced radiologists who also had access to axial sequences. Clinical relevance Our AI algorithm accurately classifies LCCS from sagittal MRI, matching experienced radiologists. This study offers a promising tool for automated LCCS assessment from sagittal T2 MRI, potentially reducing the reliance on additional axial imaging.

International consensus-based ranking of definitions for poor response to primary total knee arthroplasty: a Delphi study.

INTRODUCTION: This study aimed to rank definitions for measuring poor response one year after TKA, after assessing the face validity and feasibility of existing or newly proposed definitions. MATERIALS AND METHODS: An international, three-round, online modified Delphi study was conducted with sixty-nine panelists from twenty-three countries. Definitions were derived from a literature review or were newly proposed by an expert group. Panelists rated the face validity and feasibility of definitions, and could propose additional new definitions in round 1. Panelists reconsidered their rating of existing definitions, and rated newly suggested definitions (round 2). Definitions with a median score for face validity < 6.5 were removed from the list, and panelists distributed 100 points among the remaining definitions for ranking (round 3). RESULTS: Fifty-one panelists completed all three rounds (response rate 74%), and the prioritized list of definitions in round 3 comprised seventeen definitions. The single-item definition of (dis)satisfaction with the outcome of TKA obtained the highest scores for face validity and feasibility (7.5, and 8.5 respectively), and the definition "No improvement in pain OR daily knee functioning compared to pre-operative status" was the highest prioritized. In general, definitions reflecting change from the perception of patients were higher ranked than definitions requiring both preoperative and postoperative assessment of validated questionnaires. CONCLUSIONS: This study identified seventeen potential definitions of poor response to TKA, offering valuable options for integration into quality assessment investigations. Remarkably, all identified definitions were patient-centered and none were clinician-centered. Single-item questions, capturing change from the patient's viewpoint, appear to be the most practicable format to assess response.

The effectiveness of a protocol without routine radiographs for follow-up of adolescent idiopathic scoliosis patients (CURVE): a study protocol.

BACKGROUND AND PURPOSE: Current follow-up protocols for adolescent idiopathic scoliosis (AIS) are based on consensus and consist of regular full-spine radiographs to monitor curve progression and surgical complications. Consensus exists to avoid inappropriate use of radiographs in children. It is unknown whether a standard radiologic follow-up (S-FU) approach is necessary or if a patient-empowered follow-up (PE-FU) approach can reduce the number of radiographs without treatment consequences. METHODS AND ANALYSES: A nationwide multicenter pragmatic randomized preference trial was designed for 3 follow-up subgroups (pre-treatment, post-brace, post-surgery) to compare PE-FU and S-FU. 812 patients with AIS (age 10-18 years) will be included in the randomized trial or preference cohorts. Primary outcome is the proportion of radiographs with a treatment consequence for each subgroup. Secondary outcomes consist of the proportion of patients with delayed initiation of treatment due to non-routine radiographic follow-up, radiation exposure, societal costs, positive predictive value, and interrelation of clinical assessment, quality of life, and parameters for initiation of treatment during follow-up. Outcomes will be analyzed using linear mixed-effects models, adjusted for relevant baseline covariates, and are based on intention-to-treat principle. Study summary: (i) a national, multicenter pragmatic randomized trial addressing the optimal frequency of radiographic follow-up in patients with AIS; (ii) first study that includes patient-empowered follow-up; (iii) an inclusive study with 3 follow-up subgroups and few exclusion criteria representative for clinical reality; (iv) preference cohorts alongside to amplify generalizability; (v) first study conducting an economic evaluation comparing both follow-up approaches.

Clinical and radiological assessment of scoliosis in Koolen-de Vries syndrome.

The Koolen-de Vries syndrome (KdVS) is a multisystem disorder characterized by developmental delay, intellectual disability, characteristic facial features, epilepsy, cardiovascular and urogenital malformations, and various musculoskeletal disorders. Scoliosis is a common feature. The aim of this study is to fill the gap in the current knowledge about scoliosis in individuals with KdVS and to provide recommendations for management and follow-up. In total, 54 individuals with KdVS were included in the study, with a mean age of 13.6 years (range 1.9-38.8 years). Spine radiographs, MR scans, and corresponding radiology reports were analyzed retrospectively for scoliosis and additional anomalies. The presence of scoliosis-related clinical conditions was assessed in participants' medical records and by use of a parent survey. Scoliosis was present in 56% of the participants (30/54) with a mean age of onset of 10.6 years and curve progression during the growth spurt. Prevalence at age 6, 10, and 18 years was, respectively, 9%, 41%, and 65%. Most participants were diagnosed with a single curve (13/24, 54%), of which five participants had a long C-curve type scoliosis. No significant risk factors for development of scoliosis could be identified. Severity was mostly classified as mild, although 29% (7/24) of the curves were larger than 30° at last follow-up. Bracing therapy was received in 13% (7/54), and surgical spinal fusion was warranted in 6% (3/54). Remarkably, participants with scoliosis received less often physical therapy compared to participants without scoliosis (P = 0.002). Scoliosis in individuals with KdVS should be closely monitored and radiologic screening for scoliosis and vertebrae abnormalities is recommended at diagnosis of KdVS, and the age of 10 and 18 years.

Have Surgery and Implant Modifications Been Associated With Reduction in Soft Tissue Complications in Transfemoral Bone-anchored Prostheses?

BACKGROUND: The most frequently occurring adverse events in individuals with a transfemoral amputation treated with a bone-anchored prosthesis are soft tissue infections and stoma-related complications. These soft tissue complications are believed to be influenced by surgical technique and implant design, but little is known about the effect of changes to treatment on these events. QUESTIONS/PURPOSES: (1) What is the result of surgical technique and implant modifications on the incidence of soft tissue infections and stoma-related complications in transfemoral bone-anchored prosthesis users, depending on whether they had a conventional stoma and a cobalt-chrome-molybdenum (CoCrMo) osseointegration implant (treatment period 2009 to 2013) or a shallower stoma and titanium osseointegration implant (2015 to 2018)? (2) What is the incidence of serious complications, such as bone or implant infection, aseptic loosening, intramedullary stem breakage, and periprosthetic fracture? METHODS: Between 2009 and 2013, we performed osseointegration implant surgery using a conventional surgical technique and a CoCrMo implant in 42 individuals who had a lower extremity amputation experiencing socket-related problems that resulted in limited prosthesis use. We considered all individuals treated with two-stage surgery with a standard press-fit transfemoral osseointegration implant as potentially eligible for inclusion. Based on this, 100% (42) were eligible, and 5% (two of 42) were excluded because they did not provide informed consent, leaving 95% (40 of 42) for analysis. Between 2015 and 2018, we treated 79 individuals with similar indications with osseointegration implant surgery, now also treating individuals with dysvascular amputations. We used an adapted surgical technique resulting in a shallower stoma combined with a titanium implant. Using the same eligibility criteria as for the first group, 51% (40 of 79) were eligible; 49% (39 of 79) were excluded because they were treated with transtibial amputation, a patient-specific implant, or single-stage surgery and 1% (one of 79) were lost before the 2-year follow-up interval, leaving 49% (39 of 79) for analysis. The period of 2013 to 2015 was a transitional period and was excluded from analysis in this study to keep groups reasonably comparable and to compare a historical approach with the present approach. Hence, we presented a comparative study of two study groups (defined by surgical technique and implant design) with standardized 2-year follow-up. The risk factors for adverse events were similar between groups, although individuals treated with the shallow stoma surgical technique and titanium implant potentially possessed an increased risk because of the inclusion of individuals with dysvascular amputation and the discontinuation of prolonged postoperative antibiotic prophylaxis. Outcomes studied were soft tissue infections and stoma-related complications (hypergranulation or keloid formation as well as stoma redundant tissue) and bone or implant infection, aseptic loosening, implant stem breakage, periprosthetic fracture, and death. RESULTS: Patients treated with the shallow stoma surgical technique and titanium implant experienced fewer soft tissue infections (13 versus 76 events, absolute risk 0.17 [95% CI 0.09 to 0.30] versus 0.93 [95% CI 0.60 to 1.45]; p < 0.01), which were treated with less invasive measures, and fewer stoma redundant tissue events (0 versus five events, absolute risk 0 versus 0.06 [95% CI 0.03 to 0.14]) than patients treated with the conventional stoma surgical technique and CoCrMo implant. This was contrasted by an increased incidence of surgical site infections occurring between surgical stages 1 and 2, when no stoma was yet created, after the implementation of treatment changes (conventional surgery and CoCrMo implant versus shallow stoma surgery and titanium implant: one versus 11 events, absolute risk 0.01 [95% CI 0.00 to 0.08] versus 0.14 [95% CI 0.08 to 0.25]; p = 0.02). Patients treated with the shallow stoma surgical technique and titanium implant did not experience serious complications, although bone infections occurred (six events in 8% [three of 40] of patients) in the conventional surgery and CoCrMo implant group, all of which were successfully treated with implant retention. CONCLUSION: Adaptations to surgical technique and newer implant designs, as well as learning curve and experience, have resulted in a reduced incidence and severity of soft tissue infections and stoma redundant tissue, contrasted by an increase in surgical site infections before stoma creation. Serious complications such as deep implant infection were infrequent in this 2-year follow-up period. We believe the benefits of these treatment modifications outweigh the disadvantages and currently advise surgeons to create a shallower stoma with a stable soft tissue envelope, combined with a titanium implant. LEVEL OF EVIDENCE: Level III, therapeutic study.

Pulmonary symptoms in adolescent idiopathic scoliosis: a systematic review to identify patient-reported and clinical measurement instruments.

STUDY DESIGN: Systematic review. PURPOSE: Adolescent idiopathic scoliosis (AIS) is a deformity of the trunk and chest and can cause a spectrum of pulmonary symptoms. However, no standardized measurement instrument exists. The aim of this systematic review is to identify and describe patient-reported and clinical measurement instruments used to evaluate pulmonary symptoms in patients with AIS. METHODS: Studies published after 01.01.2000 were included in a systematic search. Patient-reported outcome measures (PROMs) and clinical measurement instruments for pulmonary symptoms were extracted as well as their measurement properties (floor-ceiling effects, validity, reliability, responsivity and interpretability). The Risk of Bias (RoB) was evaluated. RESULTS: Out of 3146 studies, 122 were eligible for inclusion. Seven clinical measurement instruments, measuring 50 measurement parameters, were identified. Five PROMs for pulmonary symptoms were identified. Studies assessing the quality of measurement properties in the AIS population were not identified. As such, the RoB could not be determined. CONCLUSION: No available adequate patent centric instruments were identified that measure pulmonary functioning and symptoms. Although clinical measurement instruments are regularly used, their use in routine practice does not seem feasible. The measurement properties of some identified PROMs seem promising; however, they have not been validated in an AIS population. As pulmonary symptoms in patients with AIS are still poorly understood, the development of such a construct and potentially a subsequent PROM to routinely measure pulmonary functioning and patient experience is recommended.

No added value of 2-year radiographic follow-up of fusion surgery for adolescent idiopathic scoliosis.

PURPOSE: For fusion surgery in adolescent idiopathic scoliosis (AIS) consensus exists that a 2-year radiographic follow-up assessment is needed. This standard lacks empirical evidence. The purpose of this study was to investigate the radiographic follow-up after corrective surgery in AIS, from pre-until 2 years postoperative. METHODS: In this historical cohort study, 63 patients surgically treated for AIS, age ≤ 25 years, with 2-year radiographic follow-up, were enrolled. The primary outcome measure was the major Cobb angle. Secondary outcomes were coronal and sagittal spino-pelvic parameters, including proximal junction kyphosis (PJK) and distal adding-on. Change over time was analyzed using a repeated measures ANOVA. RESULTS: The major curve Cobb angle showed a statistically significant change for pre- to 1 year postoperative, but not for 1- to 2-year follow-up. Seven out of 63 patients did show a change exceeding the error of measurement (5°) from 1- to 2-year follow-up (range -8° to +7°), of whom 2 patients showed curve progression and 5 showed improvement. PJK or distal adding-on was not observed. CONCLUSIONS: No statistically significant changes in major curve Cobb angle were found during postsurgical follow-up, or in adjacent non-fused segments. The findings of this study are not supportive for routine radiographs 2 years after fusion surgery in AIS patients.

Predictive factors for brace treatment outcome in adolescent idiopathic scoliosis: a best-evidence synthesis.

PURPOSE: To evaluate predictive factors for brace treatment outcome in adolescent idiopathic scoliosis (AIS) by a systematic review of the literature. METHODS: Eligible studies evaluating one or more predictive factors for brace treatment outcome were included following a systematic search in PubMed and EMBASE on October 23, 2017. Inclusion criteria were: (1) subjects diagnosed with AIS, (2) age ≤ 18 years, (3) treated with a thoraco-lumbo-sacral orthosis (TLSO), and (4) evaluated one or more predictive factors of treatment outcome (failure and/or success). The methodological quality of included studies was independently assessed by two authors. Pooling was not possible due to heterogeneity in statistical analysis. Predictive factors were presented according to a best-evidence synthesis. RESULTS: The literature search identified 26 studies that met the inclusion criteria, and multiple types of TLSO braces were identified (Boston, Wilmington, Chêneau, Osaka Medical College, Dresdner Scoliosis Orthosis and SPoRT). A total of 19 radiographic and 8 clinical predictive factors were reported. Strong evidence was found that lack of initial in-brace correction is associated with treatment failure. Moderate evidence suggests that brace wear time is associated with failure and success, whereas initial curve magnitude and curve type are not. CONCLUSION: The results of this review suggest that lack of initial in-brace correction is strongly associated with brace treatment failure. Future studies on the threshold for minimal immediate in-brace correction, as a potential indication for brace treatment, are recommended. These slides can be retrieved under Electronic Supplementary Material.

Asymmetrical trunk movement during walking improved to normal range at 3 months after corrective posterior spinal fusion in adolescent idiopathic scoliosis.

PURPOSE: To investigate the effects of posterior spinal fusion (PSF) and curve type on upper body movements in Adolescent Idiopathic Scoliosis (AIS) patients during gait. METHODS: Twenty-four girls (12-18 years) with AIS underwent PSF. 3D-Gait-analyses were performed preoperatively, at 3 months and 1 year postoperatively. Mean position (0° represents symmetry) and range of motion (ROM) of the trunk (thorax-relative-to-pelvis) in all planes were assessed. Lower body kinematics and spatiotemporal parameters were also evaluated. RESULTS: Mean trunk position improved from 7.0° to 2.9° in transversal plane and from 5.0° to - 0.8° in frontal plane at 3 months postoperative (p < 0.001), and was maintained at 1 year. Trunk ROM in transverse plane decreased from 9.6° to 7.5° (p < 0.001) after surgery. No effects of PSF were observed on the lower body kinematics during the gait cycle. Patients with a double curve had a more axial rotated trunk before and after surgery (p = 0.013). CONCLUSION: In AIS patients, during gait an evident asymmetrical position of the trunk improved to an almost symmetric situation already 3 months after PSF and was maintained at 1 year. Despite a reduction of trunk ROM, patients were able to maintain the same walking pattern in the lower extremities after surgery. This improvement of symmetry and maintenance of normal gait can explain the rapid recovery and well functioning in daily life of AIS patients, despite undergoing a fusion of large parts of their spine.

What are the risk factors for surgical site infection after spinal fusion? A meta-analysis.

PURPOSE: Although many risk factors for surgical site infection (SSI) following spinal fusion have been described in the literature, methodologies and study cohorts vary widely. Patient- and procedure-specific risk factors for (SSI) can be identified via a meta-analysis. We sought to review the existing data and isolate significant risk factors for SSI in patients undergoing thoracolumbar spinal fusion. METHODS: The literature was searched through December of 2016. Studies including adult patients undergoing thoracolumbar spinal fusion surgery (single or multilevel, anterior, posterior or combined approach) were identified. Only studies that included an odds ratio (OR) for SSI or sufficient data to calculate it were included. A meta-analysis was performed using RevMan 5.1. Depending on heterogeneity (I2), OR with 95% confidence intervals was calculated using either the fixed-effects model (when I2 < 60%) or the random-effects model (when I2 > 60%). RESULTS: 6482 manuscripts were identified and reviewed. 29 manuscripts with 374,488 patients met the criteria for inclusion. Twelve risk factors were assessed by the meta-analysis and grouped into two categories (patient related and procedure related). Significant patient-related factors for SSI included obesity, diabetes, ASA score, tobacco use and revision status. Procedure-related risk factors included operative time, use of osteotomy, fusion length and extension of fusion to the sacrum or pelvis. CONCLUSIONS: This meta-analysis identified significant risk factors for SSI following spine arthrodesis. These included potentially modifiable factors such as obesity, diabetes, smoking status and procedure-related parameters. Non-modifiable risk factors were identified, including ASA score and age. These factors may prove useful for patient counseling as well as surgical planning. LEVEL OF EVIDENCE: Level III (Meta-analysis including studies with a level of evidence of III or higher). These slides can be retrieved under Electronic Supplementary Material.

An international consensus on the appropriate evaluation and treatment for adults with spinal deformity.

PURPOSE: Evaluation and surgical management for adult spinal deformity (ASD) patients varies between health care providers. The purpose of this study is to identify appropriateness of specific approaches and management strategies for the treatment of ASD. METHODS: From January to July 2015, the AOSpine Knowledge Deformity Forum performed a modified Delphi survey where 53 experienced deformity surgeons from 24 countries, rated the appropriateness of management strategies for multiple ASD clinical scenarios. Four rounds were performed: three surveys and a face-to-face meeting. Consensus was achieved with ≥70% agreement. RESULTS: Appropriate surgical goals are improvement of function, pain, and neural symptoms. Appropriate preoperative patient evaluation includes recording information on history and comorbidities, and radiographic workup, including long standing films and MRI for all patients. Preoperative pulmonary and cardiac testing and DEXA scan is appropriate for at-risk patients. Intraoperatively, appropriate surgical strategies include long fusions with deformity correction for patients with large deformity and sagittal imbalance, and pelvic fixation for multilevel fusions with large curves, sagittal imbalance, and osteoporosis. Decompression alone is inappropriate in patients with large curves, sagittal imbalance, and progressive deformity. It is inappropriate to fuse to L5 in patients with symptomatic disk degeneration at L5-S1. CONCLUSIONS: These results provide guidance for informed decision-making in the evaluation and management of ASD. Appropriate care for ASD, a very diverse spectrum of disease, must be responsive to patient preference and values, and considerations of the care provider, and the healthcare system. A monolithic approach to care should be avoided.

High incidence of intraoperative calcar fractures with the cementless CLS Spotorno stem.

INTRODUCTION: This study reports on the incidence of intraoperative calcar fractures with the cementless Spotorno (CLS) stem, and the potential role of a learning curve and implant positioning is investigated. METHODS: After introduction of the CLS stem, 800 consecutive cementless total hip arthroplasties (THA) were analyzed. The incidence of calcar fracture in the first 400 THA was compared with the second 400 THA, in order to study a potential learning curve effect. According to the instruction for users, varus positioning of the stem was avoided and a femoral neck osteotomy was aimed relatively close to the lesser trochanter since these are assumed to be correlated with calcar fractures. Implant positioning (neck-shaft angle, femoral offset and osteotomy-lesser trochanter distance) was measured on postoperative pelvic radiographs of all THA with calcar fractures and 100 randomly selected uncomplicated control cases. RESULTS: Seventeen (2.1%) intraoperative calcar fractures were recorded. The incidence of calcar fracture differed between the first 400 THA (n = 11) and the second 400 THA (n = 6). This difference was not statistically significant (p = 0.220); however, these numbers indicate a trend toward a learning effect. No significant difference in stem positioning nor the height of the femoral neck osteotomy was measured between THA with a calcar fracture (n = 17) and the control cases (n = 100). CONCLUSIONS: We report on a high incidence of intraoperative calcar fractures with the use of a CLS stem. The risk for calcar fractures remains clinically significant even after adequate implant positioning in the hands of experienced hip surgeons. Surgeons should be aware of this implant related phenomenon and be alert on this phenomenon intraoperatively.

Which patient-reported factors predict referral to spinal surgery? A cohort study among 4987 chronic low back pain patients.

PURPOSE: It is unknown which chronic low back pain (CLBP) patients are typically referred to spinal surgery. The present study, therefore, aimed to explore which patient-reported factors are predictive of spinal surgery referral among CLBP patients. METHODS: CLBP patients were consecutively recruited from a Dutch orthopedic hospital specialized in spine care (n = 4987). The outcome of this study was referral to spinal surgery (yes/no), and was assessed using hospital records. Possible predictive factors were assessed using a screening questionnaire. A prediction model was constructed using logistic regression, with backwards selection and p < 0.10 for keeping variables in the model. The model was internally validated and evaluated using discrimination and calibration measures. RESULTS: Female gender, previous back surgery, high intensity leg pain, somatization, and positive treatment expectations increased the odds of being referred to spinal surgery, while being obese, having comorbidities, pain in the thoracic spine, increased walking distance, and consultation location decreased the odds. The model's fit was good (X 2 = 10.5; p = 0.23), its discriminative ability was poor (AUC = 0.671), and its explained variance was low (5.5%). A post hoc analysis indicated that consultation location was significantly associated with spinal surgery referral, even after correcting for case-mix variables. CONCLUSION: Some patient-reported factors could be identified that are predictive of spinal surgery referral. Although the identified factors are known as common predictive factors of surgery outcome, they could only partly predict spinal surgery referral.

Measuring outcomes in adult spinal deformity surgery: a systematic review to identify current strengths, weaknesses and gaps in patient-reported outcome measures.

PURPOSE: Adult spinal deformity (ASD) causes severe disability, reduces overall quality of life, and results in a substantial societal burden of disease. As healthcare is becoming more value based, and to facilitate global benchmarking, it is critical to identify and standardize patient-reported outcome measures (PROMs). This study aims to identify the current strengths, weaknesses, and gaps in PROMs used for ASD. METHODS: Studies were included following a systematic search in multiple bibliographic databases between 2000 and 2015. PROMs were extracted and linked to the outcome domains of WHO's International Classification of Functioning and Health (ICF) framework. Subsequently, the clinimetric quality of identified PROMs was evaluated. RESULTS: The literature search identified 144 papers that met the inclusion criteria, and nine frequently used PROMs were identified. These covered 29 ICF outcome domains, which could be grouped into three of the four main ICF chapters: body function (n = 7), activity and participation (n = 19), environmental factors (n = 3), and body structure (n = 0). A low quantity (n = 3) of papers was identified that studied the clinimetric quality of PROMs. The Scoliosis Research Society (SRS)-22 has the highest level of clinimetric quality for ASD. CONCLUSIONS: Outcome domains related to mobility and pain were well represented. We identified a gap in current outcome measures regarding neurological and pulmonary function. In addition, no outcome domains were measured in the ICF chapter body structure. These results will serve as a foundation for the process of seeking international consensus on a standard set of outcome domains, accompanied PROMs and contributing factors to be used in future clinical trials and spine registries.

Defining a core outcome set for adolescent and young adult patients with a spinal deformity.

Background and purpose - Routine outcome measurement has been shown to improve performance in several fields of healthcare. National spine surgery registries have been initiated in 5 Nordic countries. However, there is no agreement on which outcomes are essential to measure for adolescent and young adult patients with a spinal deformity. The aim of this study was to develop a core outcome set (COS) that will facilitate benchmarking within and between the 5 countries of the Nordic Spinal Deformity Society (NSDS) and other registries worldwide. Material and methods - From August 2015 to September 2016, 7 representatives (panelists) of the national spinal surgery registries from each of the NSDS countries participated in a modified Delphi study. With a systematic literature review as a basis and the International Classification of Functioning, Disability and Health framework as guidance, 4 consensus rounds were held. Consensus was defined as agreement between at least 5 of the 7 representatives. Data were analyzed qualitatively and quantitatively. Results - Consensus was reached on the inclusion of 13 core outcome domains: "satisfaction with overall outcome of surgery", "satisfaction with cosmetic result of surgery", "pain interference", physical functioning", "health-related quality of life", "recreation and leisure", "pulmonary fatigue", "change in deformity", "self-image", "pain intensity", "physical function", "complications", and "re-operation". Panelists agreed that the SRS-22r, EQ-5D, and a pulmonary fatigue questionnaire (yet to be developed) are the most appropriate set of patient-reported measurement instruments that cover these outcome domains. Interpretation - We have identified a COS for a large subgroup of spinal deformity patients for implementation and validation in the NSDS countries. This is the first study to further develop a COS in a global perspective.

De novo degenerative lumbar scoliosis: a systematic review of prognostic factors for curve progression.

PURPOSE: To identify prognostic factors for curve progression in de novo degenerative lumbar scoliosis (DNDLS) by performing a systematic review of the literature. METHODS: Studies were selected for inclusion following a systematic search in the bibliographic databases PubMed and EMBASE prior to September 2015 and hand searches of the reference lists of retrieved articles. Two authors independently assessed methodological quality. Data were extracted and presented according to a best evidence synthesis. RESULTS: The literature search generated a total of 2696 references. After removing duplicates and articles that did not meet inclusion criteria, 12 studies were included. Due to the lack of statistical analyses, pooling of data was not possible. Strong evidence indicates that increasing intervertebral disk degeneration, lateral vertebral translation ≥6 mm, and an intercrest line through L5 (rather than L4) are associated with DNDLS curve progression. Moderate evidence suggests that apical vertebral rotation Grade II or III is associated with curve progression. For the majority of other prognostic factors, we found limited, conflicting, or inconclusive evidence. Osteoporosis, a coronal Cobb angle <30°, lumbar lordosis, lateral osteophytes difference of ≥5 mm, and degenerative spondylolisthesis have not been shown to be risk factors. Clinical risk factors for progression were not identified. CONCLUSIONS: This review shows strong evidence that increased intervertebral disk degeneration, an intercrest line through L5, and apical lateral vertebral translation ≥6 mm are associated with DNDLS curve progression. Moderate evidence was found for apical vertebral rotation (Grade II/III) as a risk factor for curve progression. These results, however, may not be directly applicable to the individual patient.

Evidence and practice in spine registries.

BACKGROUND AND PURPOSE: We performed a systematic review and a survey in order to (1) evaluate the evidence for the impact of spine registries on the quality of spine care, and with that, on patient-related outcomes, and (2) evaluate the methodology used to organize, analyze, and report the "quality of spine care" from spine registries. METHODS: To study the impact, the literature on all spinal disorders was searched. To study methodology, the search was restricted to degenerative spinal disorders. The risk of bias in the studies included was assessed with the Newcastle-Ottawa scale. Additionally, a survey among registry representatives was performed to acquire information about the methodology and practice of existing registries. RESULTS: 4,273 unique references up to May 2014 were identified, and 1,210 were eligible for screening and assessment. No studies on impact were identified, but 34 studies were identified to study the methodology. Half of these studies (17 of the 34) were judged to have a high risk of bias. The survey identified 25 spine registries, representing 14 countries. The organization of these registries, methods used, analytical approaches, and dissemination of results are presented. INTERPRETATION: We found a lack of evidence that registries have had an impact on the quality of spine care, regardless of whether intervention was non-surgical and/or surgical. To improve the quality of evidence published with registry data, we present several recommendations. Application of these recommendations could lead to registries showing trends, monitoring the quality of spine care given, and ultimately improving the value of the care given to patients with degenerative spinal disorders.

Optimal surgical care for adolescent idiopathic scoliosis: an international consensus.

PURPOSE: The surgical management of adolescent idiopathic scoliosis (AIS) has seen many developments in the last two decades. Little high-level evidence is available to support these changes and guide treatment. This study aimed to identify optimal operative care for adolescents with AIS curves between 40° and 90° Cobb angle. METHODS: From July 2012 to April 2013, the AOSpine Knowledge Forum Deformity performed a modified Delphi survey where current expert opinion from 48 experienced deformity surgeons, representing 29 diverse countries, was gathered. Four rounds were performed: three web-based surveys and a final face-to-face meeting. Consensus was achieved with ≥ 70% agreement. Data were analyzed qualitatively and quantitatively. RESULTS: Consensus of what constitutes optimal care was reached on greater than 60 aspects including: preoperative radiographs; posterior as opposed to anterior (endoscopic) surgical approaches; use of intraoperative spinal cord monitoring; use of local autologous bone (not iliac crest) for grafts; use of thoracic and lumbar pedicle screws; use of titanium anchor points; implant density of <80% for 40°-70° curves; and aspects of postoperative care. Variability in practice patterns was found where there was no consensus. In addition, there was consensus on what does not constitute optimal care, including: routine pre- and intraoperative traction; routine anterior release; use of bone morphogenetic proteins; and routine postoperative CT scanning. CONCLUSIONS: International consensus was found on many aspects of what does and does not constitute optimal operative care for adolescents with AIS. In the absence of current high-level evidence, at present, these expert opinion findings will aid health care providers worldwide define appropriate care in their regions. Areas with no consensus provide excellent insight and priorities for future research.