Methodological aspects of a randomized within-patient concurrent controlled design for clinical trials in spine surgery.

INTRODUCTION: Randomized controlled trials are considered the highest level of evidence, but their feasibility in the surgical field is severely hampered by methodological and practical issues. Concurrent comparison between the experimental and control conditions within the same patient can be an effective strategy to mitigate some of these challenges and improve generalizability, mainly by the elimination of between-patient variability and reduction of the required sample size. This article aims (1) to describe the methodological aspects of a randomized within-patient controlled trial and (2) to quantify the added value of this design, based on a recently completed randomized within-patient controlled trial on bone grafts in instrumented lumbar posterolateral spinal fusion. METHODS: Boundary conditions for the application of the randomized within-patient controlled trial design were identified. Between-patient variability was quantified by the intraclass correlation coefficient and concordance in the primary fusion outcome. Sample size, study duration and costs were compared with a classic randomized controlled trial design. RESULTS: Boundary conditions include the concurrent application of the experimental and control conditions to identical but physically separated sites. Moreover, the outcome of interest should be local, uncorrelated and independently assessable. The spinal fusion outcomes within a patient were found to be more similar than between different patients (intraclass correlation coefficient 32% and concordance 64%), demonstrating a clear effect of patient-related factors. The randomized within-patient controlled trial design allowed a reduction of the sample size to one-third of a parallel-group randomized controlled trial, thereby halving the trial duration and costs. CONCLUSION: When suitable, the randomized within-patient controlled trial is an efficient design that provides a solution to some of the considerable challenges of a classic randomized controlled trial in (spine) surgery. This design holds specific promise for efficacy studies of non-active bone grafts in instrumented posterolateral fusion surgery.

Measurement of kyphosis and vertebral body height loss in traumatic spine fractures: an international study.

PURPOSE: To investigate whether wide variations are seen in the measurement techniques preferred by spine surgeons around the world to assess traumatic fracture kyphosis and vertebral body height loss (VBHL). METHODS: An online survey was conducted at two time points among an international community of spine trauma experts from all world regions. The first survey (TL-survey) focused on the thoracic, thoracolumbar and lumbar spine, the second survey (C-survey) on the subaxial cervical spine. Participants were asked to indicate which measurement technique(s) they used for measuring kyphosis and VBHL. Descriptive statistics, frequency analysis and the Fisher exact test were used to analyze the responses. RESULTS: Of the 279 invited experts, 107 (38.4 %) participated in the TL-survey, and 108 (38.7 %) in the C-survey. The Cobb angle was the most frequently used for all spine regions to assess kyphosis (55.6-75.7 %), followed by the wedge angle and adjacent endplates method. Concerning VBHL, the majority of the experts used the vertebral body compression ratio in all spine regions (51.4-54.6 %). The most frequently used combination for kyphosis was the Cobb and wedge angles. Considerable differences were observed between the world regions, while fewer differences were seen between surgeons with different degrees of experience. CONCLUSIONS: This study identified worldwide variations in measurement techniques preferred by treating spine surgeons to assess fracture kyphosis and VBHL in spine trauma patients. These results establish the importance of standardizing assessment parameters in spine trauma care, and can be taken into account to further investigate these radiographic parameters.

Development of the AOSpine Patient Reported Outcome Spine Trauma (AOSpine PROST): a universal disease-specific outcome instrument for individuals with traumatic spinal column injury.

PURPOSE: To report on the multi-phase process used in developing the AOSpine Patient Reported Outcome Spine Trauma (AOSpine PROST), as well as the results of its application in a pilot study. METHODS: The International Classification of Functioning, Disability and Health (ICF) methodology was used as the basis for the development of this tool. Four preparatory studies and a consensus conference were performed, and resulted in the selection of 25 core ICF categories as well as the scale for use. The first draft of the Dutch version of AOSpine PROST was pilot tested among a consecutively selected representative sample of 25 spine trauma patients, using the 'think aloud' and 'probing' methods. RESULTS: Of the 25 core ICF categories, 9 related to body functions, 14 activities and participation, and 2 environmental factors. Those 25 core categories were implemented into the selected response scale, and resulted in a draft version of AOSpine PROST consisting of 19 items. From the pilot study, very satisfactory results were obtained for comprehensibility, relevance, acceptability, feasibility and completeness, as well as high internal consistency (Cronbach's α = 0.926). CONCLUSIONS: Following the ICF methodology and including the results of 4 different preparatory studies and a consensus conference, the AOSpine PROST is developed. Taking the results from the subsequent pilot study into account, a definite version to be further validated will be developed. The AOSpine PROST has the potential to be a helpful tool in clinical practice and research to compare various treatments and improve the quality of health care.

Missed low-grade infection in suspected aseptic loosening has no consequences for the survival of total hip arthroplasty.

BACKGROUND AND PURPOSE: Aseptic loosening and infection are 2 of the most common causes of revision of hip implants. Antibiotic prophylaxis reduces not only the rate of revision due to infection but also the rate of revision due to aseptic loosening. This suggests under-diagnosis of infections in patients with presumed aseptic loosening and indicates that current diagnostic tools are suboptimal. In a previous multicenter study on 176 patients undergoing revision of a total hip arthroplasty due to presumed aseptic loosening, optimized diagnostics revealed that 4-13% of the patients had a low-grade infection. These infections were not treated as such, and in the current follow-up study the effect on mid- to long-term implant survival was investigated. PATIENTS AND METHODS: Patients were sent a 2-part questionnaire. Part A requested information about possible re-revisions of their total hip arthroplasty. Part B consisted of 3 patient-related outcome measure questionnaires (EQ5D, Oxford hip score, and visual analog scale for pain). Additional information was retrieved from the medical records. The group of patients found to have a low-grade infection was compared to those with aseptic loosening. RESULTS: 173 of 176 patients from the original study were included. In the follow-up time between the revision surgery and the current study (mean 7.5 years), 31 patients had died. No statistically significant difference in the number of re-revisions was found between the infection group (2 out of 21) and the aseptic loosening group (13 out of 152); nor was there any significant difference in the time to re-revision. Quality of life, function, and pain were similar between the groups, but only 99 (57%) of the patients returned part B. INTERPRETATION: Under-diagnosis of low-grade infection in conjunction with presumed aseptic revision of total hip arthroplasty may not affect implant survival.

Efficacy of Biphasic Calcium Phosphate Ceramic With a Needle-shaped Surface Topography Versus Autograft in Instrumented Posterolateral Spinal Fusion: A Randomized Trial.

STUDY DESIGN: A multicenter randomized controlled noninferiority trial with intrapatient comparisons. OBJECTIVE: The aim of this study was to determine noninferiority of a slowly resorbable Biphasic Calcium Phosphate with submicron microporosity (BCP<µm, MagnetOs™ Granules) as an alternative for autograft in instrumented posterolateral fusion (PLF). SUMMARY OF BACKGROUND DATA: Successful spinal fusion with a solid bone bridge between the vertebrae is traditionally achieved by grafting with autologous iliac bone. However, the disadvantages of autograft and unsatisfactory fusion rates have prompted the exploration of alternatives, including ceramics. Nevertheless, clinical evidence for the standalone use of these materials is limited. METHODS: Adults indicated for instrumented PLF (one to six levels) were enrolled at five participating centers. After bilateral instrumentation and fusion-bed preparation, the randomized allocation side (left or right) was disclosed. Per segment 10cc of BCP<µm granules (1-2 mm) was placed in the posterolateral gutter on one side and 10cc autograft on the contralateral side. Fusion was systematically scored on 1-year follow-up CT scans. The study was powered to detect >15% inferiority with binomial paired comparisons of the fusion performance score per treatment side. RESULTS: Of the 100 patients (57 ± 12.9 years, 62% female), 91 subjects and 128 segments were analyzed. The overall posterolateral fusion rate per segment (left and/or right) was 83%. For the BCP<µm side only the fusion rate was 79% vs. 47% for the autograft side (difference 32 percentage points, 95% CI = 23-41). Analysis of the primary outcome confirmed the noninferiority of BCP<µm with an absolute difference in paired proportions of 39.6% (95% CI = 26.8-51.2, < 0.001). CONCLUSION: This clinical trial demonstrates noninferiority and even indicates superiority of MagnetOs™ Granules as a standalone ceramic compared to autograft for posterolateral spinal fusion. These results challenge the belief that autologous bone is the most optimal graft material.

Radiologic Assessment of Interbody Fusion: A Systematic Review on the Use, Reliability, and Accuracy of Current Fusion Criteria.

BACKGROUND: Lumbar interbody fusion (IF) is a common procedure to fuse the anterior spine. However, a lack of consensus on image-based fusion assessment limits the validity and comparison of IF studies. This systematic review aims to (1) report on IF assessment strategies and definitions and (2) summarize available literature on the diagnostic reliability and accuracy of these assessments. METHODS: Two searches were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Search 1 identified studies on adult lumbar IF that provided a detailed description of image-based fusion assessment. Search 2 analyzed studies on the reliability of specific fusion criteria/classifications and the accuracy assessed with surgical exploration. RESULTS: A total of 442 studies were included for search 1 and 8 studies for search 2. Fusion assessment throughout the literature was highly variable. Eighteen definitions and more than 250 unique fusion assessment methods were identified. The criteria that showed most consistent use were continuity of bony bridging, radiolucency around the cage, and angular motion <5°. However, reliability and accuracy studies were scarce. CONCLUSION: This review highlights the challenges in reaching consensus on IF assessment. The variability in IF assessment is very high, which limits the translatability of studies. Accuracy studies are needed to guide innovations of assessment. Future IF assessment strategies should focus on the standardization of computed tomography-based continuity of bony bridging. Knowledge from preclinical and imaging studies can add valuable information to this ongoing discussion. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Assessment of Posterolateral Lumbar Fusion: A Systematic Review of Imaging-Based Fusion Criteria.

BACKGROUND: Noninvasive assessment of osseous fusion after spinal fusion surgery is essential for timely diagnosis of patients with symptomatic pseudarthrosis and for evaluation of the performance of spinal fusion procedures. There is, however, no consensus on the definition and assessment of successful posterolateral fusion (PLF) of the lumbar spine. This systematic review aimed to (1) summarize the criteria used for imaging-based fusion assessment after instrumented PLF and (2) evaluate their diagnostic accuracy and reliability. METHODS: First, a search of the literature was conducted in November 2018 to identify reproducible criteria for imaging-based fusion assessment after primary instrumented PLF between T10 and S1 in adult patients, and to determine their frequency of use. A second search in July 2021 was directed at primary studies on the diagnostic accuracy (with surgical exploration as the reference) and/or reliability (interobserver and intraobserver agreement) of these criteria. Article selection and data extraction were performed by at least 2 reviewers independently. The methodological quality of validation studies was assessed with the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) and QAREL (Quality Appraisal of Reliability Studies). RESULTS: Of the 187 articles included from the first search, 47% used a classification system and 63% used ≥1 descriptive criterion related to osseous bridging (104 articles), absence of motion (78 articles), and/or absence of static signs of nonunion (39 articles). A great variation in terminology, cutoff values, and assessed anatomical locations was observed. While the use of computed tomography (CT) increased over time, radiographs remained predominant. The second search yielded 11 articles with considerable variation in outcomes and quality concerns. Agreement between imaging-based assessment and surgical exploration with regard to demonstration of fusion ranged between 55% and 80%, while reliability ranged from poor to excellent. CONCLUSIONS: None of the available criteria for noninvasive assessment of fusion status after instrumented PLF were demonstrated to have both sufficient accuracy and reliability. Further elaboration and validation of a well-defined systematic CT-based assessment method that allows grading of the intertransverse and interfacet fusion mass at each side of each fusion level and includes signs of nonunion is recommended. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Increasing Fusion Rate Between 1 and 2 Years After Instrumented Posterolateral Spinal Fusion and the Role of Bone Grafting.

STUDY DESIGN: Two-year clinical and radiographic follow-up of a double-blind, multicenter, randomized, intra-patient controlled, non-inferiority trial comparing a bone graft substitute (AttraX Putty) with autograft in instrumented posterolateral fusion (PLF) surgery. OBJECTIVES: The aim of this study was to compare PLF rates between 1 and 2 years of follow-up and between graft types, and to explore the role of bone grafting based on the location of the PLF mass. SUMMARY OF BACKGROUND DATA: There are indications that bony fusion proceeds over time, but it is unknown to what extent this can be related to bone grafting. METHODS: A total of 100 adult patients underwent a primary, single- or multilevel, thoracolumbar PLF. After instrumentation and preparation for grafting, the randomized allocation side of AttraX Putty was disclosed. The contralateral posterolateral gutters were grafted with autograft. At 1-year follow-up, and in case of no fusion at 2 years, the fusion status of both sides of each segment was blindly assessed on CT scans. Intertransverse and facet fusion were scored separately. Difference in fusion rates after 1 and 2 years and between grafts were analyzed with a Generalized Estimating Equations (GEE) model (P < 0.05). RESULTS: The 2-year PLF rate (66 patients) was 70% at the AttraX Putty and 68% at the autograft side, compared to 55% and 52% after 1 year (87 patients). GEE analysis demonstrated a significant increase for both conditions (odds ratio 2.0, 95% confidence interval 1.5-2.7, P < 0.001), but no difference between the grafts (P = 0.595). Ongoing bone formation was only observed between the facet joints. CONCLUSION: This intra-patient controlled trial demonstrated a significant increase in PLF rate between 1 and 2 years after instrumented thoracolumbar fusion, but no difference between AttraX Putty and autograft. Based on the location of the PLF mass, this increase is most likely the result of immobilization instead of grafting. LEVEL OF EVIDENCE: 1.

Efficacy of a Standalone Microporous Ceramic Versus Autograft in Instrumented Posterolateral Spinal Fusion: A Multicenter, Randomized, Intrapatient Controlled, Noninferiority Trial.

STUDY DESIGN: in the rest of the article written as patient- and observer-blinded, multicenter, randomized, intrapatient controlled, noninferiority trial. OBJECTIVE: The aim of this study was to determine noninferiority of a biphasic calcium-phosphate (AttraX® Putty) as a bone graft substitute for autograft in instrumented posterolateral fusion (PLF). SUMMARY OF BACKGROUND DATA: Spinal fusion with autologous bone graft is a frequently performed surgical treatment. Several drawbacks of autografting have driven the development of numerous alternatives including synthetic ceramics. However, clinical evidence for the standalone use of these materials is limited. METHODS: This study included 100 nontraumatic adults who underwent a primary, single- or multilevel, thoracolumbar, instrumented PLF. After instrumentation and preparation for grafting, the randomized allocation side of AttraX® Putty was disclosed. Autograft was applied to the contralateral side of the fusion trajectory, so each patient served as his/her own control. For the primary efficacy outcome, PLF was assessed at 1-year follow-up on computed tomography scans. Each segment and side was scored as fused, doubtful fusion, or nonunion. After correction for multilevel fusions, resulting in a single score per side, the fusion performance of AttraX Putty was tested with a noninferiority margin of 15% using a 90% confidence interval (CI). RESULTS: There were 49 males and 51 females with a mean age of 55.4 ±â€Š12.0 (range 27-79) years. Two-third of the patients underwent a single-level fusion and 62% an additional interbody fusion procedure. The primary analysis was based on 87 patients, including 146 instrumented segments. The fusion rate of AttraX Putty was 55% versus 52% at the autograft side, with an overall fusion rate of 71%. The 90% CI around the difference in fusion performance excluded the noninferiority margin (difference = 2.3%, 90% CI = -9.1% to +13.7%). CONCLUSION: The results of this noninferiority trial support the use of AttraX Putty as a standalone bone graft substitute for autograft in instrumented thoracolumbar PLF. LEVEL OF EVIDENCE: 1.

Malnutrition in patients who underwent surgery for spinal metastases.

BACKGROUND: Malnutrition is common among cancer patients and has been associated with increased morbidity and mortality. The primary objective of this study was to evaluate the nutritional status of patients who underwent surgical treatment for spinal metastases. In addition, the association between nutritional status and length of stay, health related quality of life (HRQOL), the occurrence of adverse events and survival was investigated. METHODS: A single center prospective observational cohort study including patients with spinal metastases who underwent surgical treatment was performed. Demographic, diagnostic, treatment, and HRQOL (SOSGOQ2.0 and EQ-5D-3L) data were prospectively collected at baseline and 12 weeks post-treatment. Nutritional status was evaluated with the Patient-Generated Subjective Global Assessment (PG-SGA). RESULTS: A total of 39 patients were included. Malnutrition as determined by the PG-SGA was present in 36 (92%) of the patients, of whom 32 (82%) were moderately malnourished and 4 (10%) were severely malnourished. Malnourishment was associated with lower baseline SOSGOQ2.0 total scores, SOSGOQ2.0 physical function, mental health and social functioning scores, EQ-5D total scores and EQ-5D mobility scores. No association between malnutrition and survival could be determined. CONCLUSIONS: The prevalence of malnutrition among surgically treated patients with spinal metastases is high. Malnutrition demonstrated to be associated with lower baseline HRQOL scores. Future larger studies are needed to further investigate the prognostic significance of malnutrition.

Patients Cannot Reliably Distinguish the Iliac Crest Bone Graft Donor Site From the Contralateral Side After Lumbar Spine Fusion: A Patient-blinded Randomized Controlled Trial.

STUDY DESIGN: A multicenter, randomized, intrapatient controlled trial. OBJECTIVE: This study investigated whether lumbar fusion patients blinded to the harvest site (A) can identify the iliac crest used for bone harvesting and (B) whether this iliac crest is more painful than the contralateral side. SUMMARY OF BACKGROUND DATA: Spinal fusion with iliac crest autograft is a frequently performed surgical procedure. A widely reported disadvantage of the harvesting procedure is potential donor site morbidity. This has driven the development of many bone graft substitutes. However, more recently the incidence and severity of donor site pain is debated, especially in lumbar fusion surgery. METHODS: Ninety-two nontraumatic adult patients underwent a posterolateral (thoraco)lumbar fusion. Iliac crest bone graft was harvested unilaterally through the primary midline incision. At 6 weeks, 3 months, 6 months, and 1 year follow-up, patients were asked to identify the donor site and to rate pain in their back, left iliac crest and right iliac crest on a Visual Analogue Scale (VAS). RESULTS: Ninety patients, 44 males and 46 females with a mean age of 54 years, were analyzed. The left/right distribution of the iliac crest donor site was 50/50 and 89% of the patients underwent a lumbar fusion below L3. Only 24% patients identified the harvest site correctly. Moreover, the VAS pain scores for the donor site and contralateral iliac crest did not differ and were at each timepoint lower than the scores for back pain. CONCLUSION: This study showed that, during the first year after lumbar fusion surgery via a single midline incision approach, patients could not reliably identify the iliac crest used for bone graft harvesting and this iliac crest was not more painful than the untouched contralateral iliac crest. Therefore, donor site pain should not be the main reason to use bone graft alternatives for lumbar spinal fusion. LEVEL OF EVIDENCE: 2.

Surgeon Reported Outcome Measure for Spine Trauma: An International Expert Survey Identifying Parameters Relevant for the Outcome of Subaxial Cervical Spine Injuries.

STUDY DESIGN: International web-based survey. OBJECTIVE: To identify clinical and radiological parameters that spine surgeons consider most relevant when evaluating clinical and functional outcomes of subaxial cervical spine trauma patients. SUMMARY OF BACKGROUND DATA: Although an outcome instrument that reflects the patients' perspective is imperative, there is also a need for a surgeon reported outcome measure to reflect the clinicians' perspective adequately. METHODS: A cross-sectional online survey was conducted among a selected number of spine surgeons from all five AOSpine International world regions. They were asked to indicate the relevance of a compilation of 21 parameters, both for the short term (3 mo-2 yr) and long term (≥2 yr), on a five-point scale. The responses were analyzed using descriptive statistics, frequency analysis, and Kruskal-Wallis test. RESULTS: Of the 279 AOSpine International and International Spinal Cord Society members who received the survey, 108 (38.7%) participated in the study. Ten parameters were identified as relevant both for short term and long term by at least 70% of the participants. Neurological status, implant failure within 3 months, and patient satisfaction were most relevant. Bony fusion was the only parameter for the long term, whereas five parameters were identified for the short term. The remaining six parameters were not deemed relevant. Minor differences were observed when analyzing the responses according to each world region, or spine surgeons' degree of experience. CONCLUSION: The perspective of an international sample of highly experienced spine surgeons was explored on the most relevant parameters to evaluate and predict outcomes of subaxial cervical spine trauma patients. These results form the basis for the development of a disease-specific surgeon reported outcome measure, which will be a helpful tool in research and clinical practice. LEVEL OF EVIDENCE: 4.

Toward the Development of a Universal Outcome Instrument for Spine Trauma: A Systematic Review and Content Comparison of Outcome Measures Used in Spine Trauma Research Using the ICF as Reference.

STUDY DESIGN: A systematic literature review. OBJECTIVE: The aim of this study was (1) to identify patient-reported and clinician-based outcome measures most frequently used to evaluate the function and health of spine trauma patients, (2) to identify and quantify the concepts of these measures using the International Classification of Functioning, Disability, and Health (ICF) as reference, and (3) to describe their clinimetric properties. SUMMARY OF BACKGROUND DATA: There is a real need for a disease-specific outcome instrument to measure the effect size of various treatment options in a variety of traumatic spinal column injuries. METHODS: A systematic literature search was conducted in several databases. From the included studies, outcome measures were extracted. The items and underlying concepts of the identified outcome measures were specified and linked to the ICF categories. Finally, as far as available in literature, the clinimetric properties of the obtained measures were analyzed. RESULTS: Out of 5117 screened references, 245 were included, and 17 different frequently used outcome measures were identified. Meaningful concepts of the items and response options of the retrieved outcome measures were linked to a total of 105 different ICF categories, aggregated to 57 first- or second-level categories. The categories were linked to the components activities and participation (n = 31), body functions (n = 17), environmental factors (n = 8), and body structures (n = 1). Overall, there is only limited evidence on the measurement properties, except for some disease-specific questionnaires, such as Oswestry Disability Index, Roland-Morris Disability Questionnaire, Neck Disability Index, and Cervical Spine Outcome Questionnaire. CONCLUSION: The current systematic literature review revealed great diversity in the use and content of outcome measures to evaluate the functioning and health of spine trauma patients, with 17 different outcome measures linked to 57 unique ICF categories. This study creates an evidence base for a consensus meeting during which a core set of ICF categories for outcome measurement in spine trauma will be decided. LEVEL OF EVIDENCE: 2.

The selection of core International Classification of Functioning, Disability, and Health (ICF) categories for patient-reported outcome measurement in spine trauma patients-results of an international consensus process.

BACKGROUND CONTEXT: There is no outcome instrument specifically designed and validated for spine trauma patients without complete paralysis, which makes it difficult to compare outcomes of different treatments of the spinal column injury within and between studies. PURPOSE: The paper aimed to report on the evidence-based consensus process that resulted in the selection of core International Classification of Functioning, Disability, and Health (ICF) categories, as well as the response scale for use in a universal patient-reported outcome measure for patients with traumatic spinal column injury. STUDY DESIGN/SETTING: The study used a formal decision-making and consensus process. PATIENT SAMPLE: The sample includes patients with a primary diagnosis of traumatic spinal column injury, excluding completely paralyzed and polytrauma patients. OUTCOME MEASURES: The wide array of function and health status of patients with traumatic spinal column injury was explored through the identification of all potentially meaningful ICF categories. METHODS: A formal decision-making and consensus process integrated evidence from four preparatory studies. Three studies aimed to identify relevant ICF categories from three different perspectives. The research perspective was covered by a systematic literature review identifying outcome measures focusing on the functioning and health of spine trauma patients. The expert perspective was explored through an international web-based survey among spine surgeons from the five AOSpine International world regions. The patient perspective was investigated in an international empirical study. A fourth study investigated various response scales for their potential use in the future universal outcome instrument. This work was supported by AOSpine. AOSpine is a clinical division of the AO Foundation, an independent medically guided non-profit organization. The AOSpine Knowledge Forums are pathology-focused working groups acting on behalf of AOSpine in their domain of scientific expertise. RESULTS: Combining the results of the preparatory studies, the list of ICF categories presented at the consensus conference included 159 different ICF categories. Based on voting and discussion, 11 experts from 6 countries selected a total of 25 ICF categories as core categories for patient-reported outcome measurement in adult traumatic spinal column injury patients (9 body functions, 14 activities and participation, and 2 environmental factors). The experts also agreed to use the Numeric Rating Scale 0-100 as response scale in the future universal outcome instrument. CONCLUSIONS: A formal consensus process integrating evidence and expert opinion led to a set of 25 core ICF categories for patient-reported outcome measurement in adult traumatic spinal column injury patients, as well as the response scale for use in the future universal disease-specific outcome instrument. The adopted core ICF categories could also serve as a benchmark for assessing the content validity of existing and future outcome instruments used in this specific patient population.

Towards the development of an outcome instrument for spinal trauma: an international survey of spinal surgeons.

STUDY DESIGN: International web-based survey. OBJECTIVE: To identify the most relevant aspects of human function and health status from the perspective of health care professionals involved in the treatment of spinal trauma patients. SUMMARY OF BACKGROUND DATA: There is no universally accepted outcome instrument available that is specifically designed or validated for spinal trauma patients, contributing to controversies related to the optimal treatment and evaluation of many types of spinal injuries. Therefore, the AOSpine Knowledge Forum Trauma aims to develop such an instrument using the International Classification of Functioning, Disability, and Health (ICF) as its basis. METHODS: Experts from the 5 AOSpine International world regions were asked to give their opinion on the relevance of a compilation of 143 ICF categories for spinal trauma patients on a 3-point scale: "not relevant," "probably relevant," or "definitely relevant." The responses were analyzed using frequency analysis. Possible differences in responses between the 5 world regions were analyzed with the Fisher exact test and descriptive statistics. RESULTS: Of the 895 invited AOSpine International members, 150 (16.8%) participated in this study. A total of 13 (9.1%) ICF categories were identified as definitely relevant by more than 80% of the participants. Most of these categories were related to the ICF component "activities and participation" (n = 8), followed by "body functions" (n = 4), and "body structures" (n = 1). Only some minor regional differences were observed in the pattern of answers. CONCLUSION: More than 80% of an international group of health care professionals experienced in the clinical care of adult spinal trauma patients indicated 13 of 143 ICF categories as definitely relevant to measure outcomes after spinal trauma. This study creates an evidence base to define a core set of ICF categories for outcome measurement in adult spinal trauma patients.

Toward a specific outcome instrument for spinal trauma: how to measure function and health.

STUDY DESIGN: Validation study. OBJECTIVE: To investigate the most valid, reliable, and comprehensible response scale for spinal trauma patients to compare their current level of function and health with their preinjury state. SUMMARY OF BACKGROUND DATA: In the context of a main project of the AOSpine Knowledge Forum Trauma to develop a disease-specific outcome instrument for adult spinal trauma patients, the need to identify a response scale that uniquely reflects the degree to which a spine trauma patient has returned to his or her preinjury state is crucial. METHODS: In the first phase, 3 different question formats and 3 different response formats were investigated in a questionnaire, which was administered twice. Based on the results of the first phase, in the second phase, a modified questionnaire was administered once to a second group of patients to investigate 5 different response formats: 0-10 Numeric Rating Scale-11, 0-100 Numeric Rating Scale-101, Visual Analogue Scale, Verbal Rating Scale, and Adjective Scale. All patients were interviewed in a semistructured fashion to identify their preferences. Multiple statistical analyses were performed: test-retest reliability, internal consistency, and discriminant validity. RESULTS: Twenty eligible patients were enrolled in the first phase and 59 in the second phase. The initial phase revealed the highest preference for 1 specific question format (60.0% and 86.7% after the first and second administration of the questionnaire, respectively). The second phase showed the Verbal Rating Scale as the most preferred response format (35.6%). The semistructured interviews revealed that overall, a subgroup of patients preferred a verbal response format (42.4%), and another group of patients preferred a numerical response format (49.1%). The statistical analysis showed good to excellent psychometric properties for all formats. CONCLUSION: The most preferred question and response formats were identified for use in a disease-specific outcome instrument for spinal trauma patients. LEVEL OF EVIDENCE: 3.

Toward developing a specific outcome instrument for spine trauma: an empirical cross-sectional multicenter ICF-based study by AOSpine Knowledge Forum Trauma.

STUDY DESIGN: Empirical cross-sectional multicenter study. OBJECTIVE: To identify the most commonly experienced problems by patients with traumatic spinal column injuries, excluding patients with complete paralysis. SUMMARY OF BACKGROUND DATA: There is no disease or condition-specific outcome instrument available that is designed or validated for patients with spine trauma, contributing to the present lack of consensus and ongoing controversies in the optimal treatment and evaluation of many types of spine injuries. Therefore, AOSpine Knowledge Forum Trauma started a project to develop such an instrument using the International Classification of Functioning, Disability and Health (ICF) as its basis. METHODS: Patients with traumatic spinal column injuries, within 13 months after discharge from hospital were recruited from 9 trauma centers in 7 countries, representing 4 AOSpine International world regions. Health professionals collected the data using the general ICF Checklist. The responses were analyzed using frequency analysis. Possible differences between the world regions and also between the subgroups of potential modifiers were analyzed using descriptive statistics and Fisher exact test. RESULTS: In total, 187 patients were enrolled. A total of 38 (29.7%) ICF categories were identified as relevant for at least 20% of the patients. Categories experienced as a difficulty/impairment were most frequently related to activities and participation (n = 15), followed by body functions (n = 6), and body structures (n = 5). Furthermore, 12 environmental factors were considered to be a facilitator in at least 20% of the patients. CONCLUSION: Of 128 ICF categories of the general ICF Checklist, 38 ICF categories were identified as relevant. Loss of functioning and limitations in daily living seem to be more relevant for patients with traumatic spinal column injuries rather than pain during this time frame. This study creates an evidence base to define a core set of ICF categories for outcome measurement in adult spine trauma patients. LEVEL OF EVIDENCE: 4.

Reliability and validity of the adapted Dutch version of the revised Scoliosis Research Society 22-item questionnaire.

BACKGROUND CONTEXT: As in other fields of medicine, there is an increasing interest among orthopedic surgeons to measure health-related quality of life in adolescent idiopathic scoliosis patients and to evaluate the burden of disease and the effectiveness of different treatment strategies. The development of the revised Scoliosis Research Society 22-item patient questionnaire (SRS-22r) enabled a comprehensive evaluation of health-related quality of life of these patients. Over the years, the SRS-22r gained wide acceptance and has been used in several different countries, languages, and cultures. The SRS-22r has not been translated into Dutch to date. PURPOSE: To translate the SRS-22r into Dutch and adapt it cross-culturally as outlined by international guidelines and to test its psychometric properties to measure health-related quality of life of adolescent idiopathic scoliosis patients in the Netherlands. STUDY DESIGN/SETTING: A cross-sectional, multicenter validation study. PATIENT SAMPLE: A total of 135 adolescent idiopathic scoliosis patients (mean age 15.1 years old) of three major scoliosis centers in the Netherlands were enrolled in this study. Ninety-two (68%) subjects completed the Dutch SRS-22r, Child Health Questionnaire (CHQ)-CF87 (golden standard for adolescents), and Short Form (SF)-36 (golden standard for adults). Two weeks later, 73 (79%) of 92 respondents returned a second SRS-22r. Demographics, curve type, Risser stage, and treatment status were documented. OUTCOME MEASURES: Floor and ceiling effects, internal consistency, reproducibility, concurrent validity, and discriminative ability of the Dutch version of the SRS-22r questionnaire. METHODS: For content analysis, SRS-22r domain scores (function, pain, self-image, mental health, and satisfaction with management) were explored and floor and ceiling effects were determined. Cronbach's α was calculated for internal consistency of each domain of the questionnaires and reproducibility was assessed by test-retest reliability analysis. Using Pearson's correlation coefficient, comparison of the domains of the Dutch SRS-22r with the domains of the SF-36 and Child Health Questionnaire-CF87 assessed the concurrent validity. Differences in SRS-22r domain scores between untreated patients with different curve severity determined the discriminative ability of the questionnaire. RESULTS: The SRS-22r domains as well as the SF-36 and CHQ-CF87 domains demonstrated no floor effects, but the function, pain, and satisfaction with management domains had ceiling effects, indicating the proportion of subjects with the maximum score between 19.6% and 33.0%. Internal consistency was very satisfactory for all SRS-22r domains: Cronbach's α was between 0.718 and 0.852. By omitting question 15, the internal consistency of the function domain increased from 0.746 to 0.827. Test-retest reliability was ≥0.799 for all SRS-22r domains. The function, pain, mental health, and self-image domains correlated under the 0.001 significance level with the corresponding CHQ-CF87 and SF-36 domains. The satisfaction with management domain did not correlate with the other questionnaires. The SRS-22r had the ability to detect differences between groups with different curve severity; patients with a severe scoliotic curvature had significantly lower pain and self-image domain scores than patients with relatively mild scoliosis. CONCLUSIONS: The Dutch SRS-22r had the properties needed for the measurement of patient perceived health-related quality of life of adolescent idiopathic scoliosis patients in the Netherlands. The Dutch SRS-22r could be used for the longitudinal follow-up of adolescent idiopathic scoliosis patients from adolescence to adulthood and for establishing the effects of conservative or invasive surgical treatment.