Aims. The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition. Methods. Between July 2017 and July 2019, 40 patients with cervical OPLL were equally randomized to undergo surgery with an ACOE or a PTLF. The clinical and radiological results were compared between the two groups. Results. The Japanese Orthopaedic Association (JOA) score and recovery rate in the ACOE group were significantly higher than those in the PTLF group during two years postoperatively, provided that the canal occupying ratio (COR) was > 50%, or the K-line was negative. There was no significant difference in JOA scores and rate of recovery between the two groups in those in whom the COR was < 50%, or the K-line was positive. There was no significant difference in the Cobb angle between C2 and C7, sagittal vertical axis, cervical range of motion (ROM), and complications between the two groups. Conclusion. Compared with PTLF, ACOE is a preferred surgical approach for the surgical management of patients with cervical OPLL in that it offers a better therapeutic outcome when the COR is > 50%, or the K-line is negative, and it also preserves better cervical curvature and sagittal balance. The prognosis of ACOE is similar to that of PTLE when the COR is < 50%, or the K-line is positive. Cite this article: Bone Joint J 2023;105-B(4):412–421

Aims

People with severe, persistent low back pain (LBP) may be offered lumbar spine fusion surgery if they have had insufficient benefit from recommended non-surgical treatments. However, National Institute for Health and Care Excellence (NICE) 2016 guidelines recommended not offering spinal fusion surgery for adults with LBP, except as part of a randomized clinical trial. This survey aims to describe UK clinicians’ views about the suitability of patients for such a future trial, along with their views regarding equipoise for randomizing patients in a future clinical trial comparing lumbar spine fusion surgery to best conservative care (BCC; the FORENSIC-UK trial).

Aims

The aim of this study was to compare outcomes after growth-friendly treatment for early-onset scoliosis (EOS) between patients with skeletal dysplasias versus those with other syndromes.

Aims. There is little information about the optimum number of implants to be used in the surgical treatment of idiopathic scoliosis. Retrospective analysis of prospectively collected data from the Swedish spine register was undertaken to discover whether more implants per operated vertebra (implant density) leads to a better outcome in the treatment of idiopathic scoliosis. The hypothesis was that implant density is not associated with patient-reported outcomes, the correction of the curve or the rate of reoperation. Patients and Methods. A total of 328 patients with idiopathic scoliosis, aged between ten and 20 years at the time of surgery, were identified in the Swedish spine register (Swespine) and had patient reported outcomes including the Scoliosis Research Society 22r instrument (SRS-22r) score, EuroQol 5 dimensions quality of life, 3 level (EQ-5D-3L) score and a Viual Analogue Score (VAS) for back pain, at a mean follow-up of 3.1 years and reoperation data at a mean follow-up of 5.5 years. Implant data and the correction of the curve were assessed from radiographs, preoperatively and a mean of 1.9 years postoperatively. The patients were divided into tertiles based on implant density. Data were analyzed with analysis of variance, logistic regression or log-rank test. Some analyses were adjusted for gender, age at the time of surgery, the flexibility of the major curve and follow-up. Results. The mean number of implants per operated vertebra in the low, medium and high-density groups were 1.36 (1.00 to 1.54), 1.65 (1.55 to 1.75) and 1.91 (1.77 to 2.00), respectively. There were no statistically significant differences in the correction of the curve, the SRS-22r total score, EQ-5D-3L index or number of reoperations between the groups (all p > 0.34). In the SRS-22r domains, self-image was marginally higher in the medium implant density group (p = 0.029) and satisfaction marginally higher in the high implant density group (p = 0.034). Conclusion. These findings suggest that there is no clear advantage in using a high number of implants per operated vertebra in the surgical treatment of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2018;100-B:1080–6

Aims

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

Aims

To report the outcome of spinal deformity correction through anterior spinal fusion in wheelchair-bound patients with myelomeningocele.

The skeleton is the most common site to be affected by metastatic cancer. The place of surgical treatment and of different techniques of reconstruction has not been clearly defined. We have studied the rate of survival of 94 patients and the results of the surgical treatment of 91 metastases of the limbs and pelvis, and 18 of the spine. Variables included the different primary tumours, the metastatic load at the time of operation, the surgical margin, and the different techniques of reconstruction. The survival rate was 0.54 at one year and 0.27 at three years. Absence of visceral metastases and of a pathological fracture, a time interval of more than three years between the diagnosis of cancer and that of the first skeletal metastasis, thyroid carcinoma, prostate carcinoma, renal-cell carcinoma, breast cancer, and plasmacytoma were positive variables with regard to survival. The metastatic load of the skeleton and the surgical margin were not of significant influence. In tumours of the limbs and pelvis, the local failure rate was 0% after biological reconstruction (10), 3.6% after cemented or uncemented osteosynthesis (28) and 1.8% after prosthetic replacement (53). The local failure rate after stabilisation of the spine (18) was 16.6%. There was local recurrence in seven patients (6.4%), and in four of these the primary tumour was a renal-cell carcinoma. The local recurrence rate was 0% after extralesional (24) and 8.2% after intralesional resection (85). Improvements in the oncological management of patients with primary and metastatic disease have resulted in an increased survival rate. In order to avoid additional surgery, it is essential to consider the expected time of survival of the reconstruction and, in bony metastases with a potentially poor response to radiotherapy, the surgical margin

A combined anterior and posterior surgical approach is generally recommended in the treatment of severe congenital kyphosis, despite the fact that the anterior vascular supply of the spine and viscera are at risk during exposure. The aim of this study was to determine whether the surgical treatment of severe congenital thoracolumbar kyphosis through a single posterior approach is feasible, safe and effective. We reviewed the records of ten patients with a mean age of 11.1 years (5.4 to 14.1) who underwent surgery either by pedicle subtraction osteotomy or by vertebral column resection with instrumented fusion through a single posterior approach. The mean kyphotic deformity improved from 59.9° (45° to 110°) pre-operatively to 17.5° (3° to 40°) at a mean follow-up of 47.0 months (29 to 85). Spinal cord monitoring was used in all patients and there were no complications during surgery. These promising results indicate the possible advantages of the described technique over the established procedures. We believe that surgery should be performed in case of documented progression and before structural secondary curves develop. Our current strategy after documented progression is to recommend surgery at the age of five years and when 90% of the diameter of the spinal canal has already developed. Cite this article: Bone Joint J 2013;95-B:1527–32

Introduction. Posterior spinal arthrodesis with thoracoplasty and an open anterior approach, with respect to a posterior only fusion, have a deleterious effect on pulmonary function for up to 5 years after surgical treatment of adolescent idiopathic scoliosis. We aimed to compare two groups of adolescents surgically treated for their spinal deformity either by posterior segmental fusion alone (PSF) or by posterior spinal fusion and thoracoplasty (PSF+T). We focused on the long-term effects of thoracoplasty on pulmonary function in the surgical treatment of adolescent idiopathic scoliosis. Methods. We compared 40 consecutive adolescent patients surgically treated between 1998 and 2001 by PSF+T with a similar cohort of 40 adolescents treated in the same period by PSF. Inclusion criteria were pedicle screw instrumentation alone and a minimum 5 years of follow-up. A radiographic analysis and a chart review were done, evaluating the pulmonary function tests (PFTs), the SRS-30 score questionnaire, and the Lenke classification system. A radiographic rib-hump (RH) assessment was also undertaken. Results. The entire series was reviewed at an average clinical follow-up of 8·3 years. The two groups did not differ significantly in terms of sex, age (PSF+T 16·3 years vs PSF 15·2 years), Lenke curve type classification, and preoperative Cobb main thoracic (MT) curve magnitude (66° vs 63°); however, final MT percentage correction (53·03% vs 51·35%; p<0·03), RH absolute correction (–2·1 cm vs –1·05; p<0·01), and RH overall percentage correction (55·4% vs 35·4%; p<0·0001) were greater in the PSF+T group than in the PSF group. We recorded no statistical differences between the two groups in PFTs both preoperatively and at last follow-up. Nevertheless, comparing preoperative with final PFTs within each group, only in the PSF group was both forced vital capacity and forced expiratory volume in 1 s significantly improved at final evaluation. At last follow-up visit, the SRS-30 scores did not differ significantly between the two groups (total score 4·1 vs 4·3). Conclusions. Our findings suggest that thoracoplasty did not adversely affect long-term PFTs in patients with adolescent idiopathic scoliosis treated by posterior spinal fusion alone with pedicle screws instrumentation, as already shown in previous reports. A trend towards better coronal plane correction and rib-hump improvement was recorded, although this improvement was not clearly reported in a self-assessment disease-specific questionnaire

There have been few reports regarding the efficacy of posterior instrumentation alone as surgical treatment for patients with pyogenic spondylitis, thus avoiding the morbidity of anterior surgery. We report the clinical outcomes of six patients with pyogenic spondylitis treated effectively with a single-stage posterior fusion without anterior debridement at a mean follow-up of 2.8 years (2 to 5). Haematological data, including white cell count and level of C-reactive protein, returned to normal in all patients at a mean of 8.2 weeks (7 to 9) after the posterior fusion. Rigid bony fusion between the infected vertebrae was observed in five patients at a mean of 6.3 months (4.5 to 8) post-operatively, with the remaining patient having partial union. Severe back pain was immediately reduced following surgery and the activities of daily living showed a marked improvement. Methicillin-resistant Staphylococcus aureus was detected as the causative organism in four patients. Single-stage posterior fusion may be effective in patients with pyogenic spondylitis who have relatively minor bony destruction

Purpose of the study. We propose a simple classification for adolescent idiopathic scoliosis (AIS) based on two components which include the curve type and shoulder level and suggest a treatment algorithm for AIS. Introduction. Few Classification systems for adolescent idiopathic scoliosis (AIS) have helped in communicating, understanding and selecting a treatment for this condition; however, most of these classifications are complex and include many subtypes, making it difficult for the orthopaedic surgeon to use them in clinical practice. The variable reliability and reproducibility of these studies make recommendations and comparisons between various operative treatments a difficult task. Furthermore, none of these classifications has taken the shoulder imbalance into account, despite its importance as a clinical parameter and outcome measure. Methods. We developed a classification system with two components: curve type (I through III) and shoulder level (A or B). The curve types are divided into type I: Primary lumbar-thoracolumbar +/− secondary dorsal; type II: Primary dorsal secondary lumbar and type III: Dorsal. Each curve pattern is subdivided into type A or B depending on the shoulder level. In type A, the lower shoulder is ipsilateral to the concavity of the primary curve. In type B, the shoulders are level or the lower shoulder is on the convexity of the primary curve. This classification was tested for interobserver reliability and intraobserver reproducibility by six surgeons using radiographs of 28 patients. We performed a retrospective analysis of the radiographs of 232 consecutive AIS cases to assess the prevalence of curve types and tested the surgical treatment against the proposed treatment algorithm. Results. Three major types and six subtypes were identified, of which type I accounted for 30%, type II 28% and type III 42%. The kappa coefficient for interobserver reliability was 0.943, while the kappa value for intraobserver reproducibility was 0.964. There was a complete concordance with the shoulder level component. Of the 232 cases reviewed, with a minimum two-year follow-up, only three patients developed a decompensation distal to the instrumentation requiring fusion extension. Conclusion. This classification is the first of its kind to specifically address shoulder imbalance in the surgical decision-making process. The high interobserver reliability and intraobserver reproducibility is due in part to the simplicity of this classification, which makes it an invaluable tool to describe scoliosis curves and offers a potential treatment algorithm in correcting scoliosis

The National Institute for Health and Care Excellence has issued guidelines that state fusion for non-specific low back pain should only be performed as part of a randomised controlled trial, and that lumbar disc replacement should not be performed. Thus, spinal fusion and disc replacement will no longer be routine forms of treatment for patients with low back pain. This annotation considers the evidence upon which these guidelines are based.

Cite this article: Bone Joint J 2017;99-B:1003–1005.

We studied prospectively 22 young athletes who had undergone surgical treatment for lumbar spondylolysis. There were 15 men and seven women with a mean age of 20.2 years (15 to 34). Of these, 13 were professional footballers, four professional cricketers, three hockey players, one a tennis player and one a golfer. Preoperative assessment included plain radiography, single positron-emission CT, planar bone scanning and reverse-gantry CT. In all patients the Oswestry disability index (ODI) and in 19 the Short-Form 36 (SF-36) scores were determined preoperatively, and both were measured again after two years in all patients. Three patients had a Scott’s fusion and 19 a Buck’s fusion. The mean duration of back pain before surgery was 9.4 months (6 to 36). The mean size of the defect as determined by CT was 3.5 mm (1 to 8) and the mean preoperative and postoperative ODIs were 39.5 (. sd. 8.7) and 10.7 (. sd. 12.9), respectively. The mean scores for the physical component of the SF-36 improved from 27.1 (. sd. 5.1) to 47.8 (. sd. 7.7). The mean scores for the mental health component of the SF-36 improved from 39.0 (. sd. 3.9) to 55.4 (. sd. 6.3) with p < 0.001. After rehabilitation for a mean of seven months (4 to 10) 18 patients (82%) returned to their previous sporting activity

The SRS-22 instrument was developed to assess quality of life in adolescent idiopathic scoliosis patients (AIS). The aim of our study was to evaluate the impact of surgical treatment on quality of life in neurologically normal patients with complex spinal deformity of a range of aetiologies using the SRS-22 questionnaire. We analysed prospectively collected SRS-22 data on 407 consecutive patients (315 females-92 males) treated from 2006–2012 under the care of the senior author. 97.6% of patients had a posterior (PSF), 1.3% an anterior (ASF) and 1.1% an anterior-posterior (A/PSF) spinal fusion. Questionnaires were completed at 4 stages of treatment: preoperatively, 6-months, 12-months and 24-months postoperatively. Other variables included age at surgery, gender, diagnosis and year of surgery. 9 diagnoses were included in the study: 271 patients had AIS; 39 Scheuermann's kyphosis; 31 spondylolisthesis; 16 congenital scoliosis; 13 JIS; 6 IIS; 13 scoliosis associated with intraspinal anomalies; 11 syndromic scoliosis; 7 scoliosis associated with congenital cardiac disease. Mean age at surgery was 15.14±2.07 years. Age at surgery was divided in 3 groups to compare outcomes against previous studies: 10–12, 13–15, and 15–19 years. Mean total SRS-22 scores for the whole group were: preoperative 3.62±0.66; 6-month 4.12±0.44; 12-month 4.39±0.40; and 24-month 4.52±0.37 (p<0.0001). Individual preoperative scores for the whole group were: function 3.77±0.75; pain 3.7±0.97; self-image 3.14±0.66; mental 3.86±0.77. Mean 24-month postoperative scores for the whole group were: function 4.39±0.42; pain 4.59±0.56; self-image 4.39±0.51; mental 4.43±0.56; satisfaction 4.81±0.40. All changes observed at 2-year follow-up were statistically significant (p<0.0001). Male preoperative total score (3.64±0.66) did not have a significant difference compared to female (3.62±0.66); however 24-month total score improvement was significant, with males (4.62±0.25) performing better than females (4.49±0.39) including satisfaction (p=0.004). Spondylolisthesis patients performed worse preoperatively (2.93±0.26) compared to other diagnoses (p<0.0001); AIS 3.67±0.64, congenital 3.81±0.57, syndromic 3.80±0.54, Scheuermann's 3.48±0.75, JIS 3.90±0.63, scoliosis with congenital cardiac disease 4.04±0.41 or intraspinal anomalies 3.71±0.66, and IIS 3.58±0.80. No change in total and individual scores was observed at 24-month review across diagnoses (p>0.05). There were no significant changes between each year of surgery in the study period and the total values at each stage (p>0.05). There were no significant changes between the 3 age ranges at each stage (p>0.05). Patients undergoing ASF performed significantly better at preoperative function (4.7±0.27) compared to PSF (3.76±0.74) and A/PSF (3.68±0.72), (p=0.19). All values at 2-years were not significant in comparison regarding type of operation (p>0.05). All individual domains and total SRS-22 scores improved after surgical correction of spinal deformity in our young patient cohort with an incremental change between preoperative, 6-month, 12-month and 24-month postoperative. Our 24-month postoperative outcomes in all diagnoses compare favourably to reported SRS-22 scores in healthy adolescents (function: 4.31±0.54; pain: 4.44±0.67; image: 4.41±0.64; mental health: 3.96±0.81; total 4.26±0.54). We are planning to continue this study with longer follow-up in order to allow comparison of our SRS-22 outcomes after surgical treatment to those obtained in patients treated with bracing or patients who were followed untreated (previous reports SRS-22 total scores: 4.2 for braced patients and 4.1 for observed patients)

Lumbar disc herniation (LDH) is uncommon in youth and few cases are treated surgically. Very few outcome studies exist for LDH surgery in this age group. Our aim was to explore differences in gender in pre-operative level of disability and outcome of surgery for LDH in patients aged ≤ 20 years using prospectively collected data.

From the national Swedish SweSpine register we identified 180 patients with one-year and 108 with two-year follow-up data ≤ 20 years of age, who between the years 2000 and 2010 had a primary operation for LDH.

Both male and female patients reported pronounced impairment before the operation in all patient reported outcome measures, with female patients experiencing significantly greater back pain, having greater analgesic requirements and reporting significantly inferior scores in EuroQol (EQ-5D-index), EQ-visual analogue scale, most aspects of Short Form-36 and Oswestry Disabilities Index, when compared with male patients. Surgery conferred a statistically significant improvement in all registered parameters, with few gender discrepancies. Quality of life at one year following surgery normalised in both males and females and only eight patients (4.5%) were dissatisfied with the outcome. Virtually all parameters were stable between the one- and two-year follow-up examination.

LDH surgery leads to normal health and a favourable outcome in both male and female patients aged 20 years or younger, who failed to recover after non-operative management.

Cite this article: Bone Joint J 2015;97-B:1675–82.

We describe 13 patients with cerebral palsy and lordoscoliosis/hyperlordosis of the lumbar spine who underwent a posterior spinal fusion at a mean age of 14.5 years (10.8 to 17.4) to improve sitting posture and relieve pain. The mean follow-up was 3.3 years (2.2 to 6.2).

The mean pre-operative lumbar lordosis was 108^° (80 to 150^°) and was corrected to 62^° (43^° to 85^°); the mean thoracic kyphosis from 17^° (-23^° to 35^°) to 47^° (25^° to 65^°); the mean scoliosis from 82^° (0^° to 125^°) to 22^° (0^° to 40^°); the mean pelvic obliquity from 21^° (0^° to 38^°) to 3^° (0^° to 15^°); the mean sacral slope from 79^° (54^° to 90^°) to 50^° (31^° to 66^°). The mean pre-operative coronal imbalance was 5 cm (0 cm to 8.9 cm) and was corrected to 0.6 cm (0 to 3.2). The mean sagittal imbalance of -8 cm (-16 cm to 7.8 cm) was corrected to -1.6 cm (-4 cm to 2.5 cm). The mean operating time was 250 minutes (180 to 360 minutes) and intra-operative blood loss 0.8 of estimated blood volume (0.3 to 2 estimated blood volume). The mean intensive care and hospital stay were 3.5 days (2 to 8) and 14.5 days (10 to 27), respectively. Three patients lost a significant amount of blood intra-operatively and subsequently developed chest or urinary infections and superior mesenteric artery syndrome.

An increased pre-operative lumbar lordosis and sacral slope were associated with increased peri-operative morbidity: scoliosis and pelvic obliquity were not. A reduced lumbar lordosis and increased thoracic kyphosis correlated with better global sagittal balance at follow-up. All patients and their parents reported excellent surgical outcomes.

Lordoscoliosis and hyperlordosis are associated with significant morbidity in quadriplegic patients. They are rare deformities and their treatment is challenging. Sagittal imbalance is the major component: it can be corrected by posterior fusion of the spine with excellent functional results.

Cite this article: Bone Joint J 2014;96-B:800–6.

We carried out a retrospective review of 155 patients with lumbar spinal stenosis who had been treated surgically and followed up regularly: 77 were evaluated at a mean of 6.5 years (5 to 8) after surgery by two independent observers. The outcome was assessed using the scoring system of Roland and Morris, and the rating system of Prolo, Oklund and Butcher. Instability was determined according to the criteria described by White and Panjabi.

A significant decrease in low back pain and disability was seen. An excellent or good outcome was noted in 79% of patients; 9% showed secondary radiological instability.

Surgical decompression is a safe and efficient procedure. In the absence of preoperative radiological evidence of instability, fusion is not required.

Between 1995 and 1999, 12 patients aged 65 years or more (mean 70.2) with lumbar disc herniation, underwent partial laminectomy and nucleotomy. The results were compared with those of 25 younger patients aged between 20 and 40 years (mean 30.1), who underwent the same surgical procedure. The Japanese Orthopedic Association (JOA) score was used to assess the clinical outcome. The minimum follow-up was 12 months. The pre- and post-operative total JOA scores and the rate of improvement of the JOA score were not significantly different between the elderly (11.1, 24.3 points, and 74.1%), and the younger group (11.6, 26.4 points and 84.5%).

The results of this study indicate that the outcome of lumbar discectomy in elderly patients is as good as in younger patients.

Aims. The aim of this study was to determine whether early surgical treatment results in better neurological recovery 12 months after injury than late surgical treatment in patients with acute traumatic spinal cord injury (tSCI). Methods. Patients with tSCI requiring surgical spinal decompression presenting to 17 centres in Europe were recruited. Depending on the timing of decompression, patients were divided into early (≤ 12 hours after injury) and late (> 12 hours and < 14 days after injury) groups. The American Spinal Injury Association neurological (ASIA) examination was performed at baseline (after injury but before decompression) and at 12 months. The primary endpoint was the change in Lower Extremity Motor Score (LEMS) from baseline to 12 months. Results. The final analyses comprised 159 patients in the early and 135 in the late group. Patients in the early group had significantly more severe neurological impairment before surgical treatment. For unadjusted complete-case analysis, mean change in LEMS was 15.6 (95% confidence interval (CI) 12.1 to 19.0) in the early and 11.3 (95% CI 8.3 to 14.3) in the late group, with a mean between-group difference of 4.3 (95% CI -0.3 to 8.8). Using multiply imputed data adjusting for baseline LEMS, baseline ASIA Impairment Scale (AIS), and propensity score, the mean between-group difference in the change in LEMS decreased to 2.2 (95% CI -1.5 to 5.9). Conclusion. Compared to late surgical decompression, early surgical decompression following acute tSCI did not result in statistically significant or clinically meaningful neurological improvements 12 months after injury. These results, however, do not impact the well-established need for acute, non-surgical tSCI management. This is the first study to highlight that a combination of baseline imbalances, ceiling effects, and loss to follow-up rates may yield an overestimate of the effect of early surgical decompression in unadjusted analyses, which underpins the importance of adjusted statistical analyses in acute tSCI research. Cite this article: Bone Joint J 2023;105-B(4):400–411

Introduction. Lumbosacral transitional vertebrae (LSTV) are increasingly recognized as a common anatomical variant and is the most common congenital anomaly of the lumbosacral spine. Patients can have symptomatic LSTV, known as Bertolotti's Syndrome, where transitional anatomy can cause back, L5 distribution leg, hip, and groin pain. We propose an outline for diagnosis and treatment of Bertolotti's Syndrome. Methods. We retrospectively reviewed over 500 patients presenting to the primary author with low back, buttock, hip, groin and/or leg pain from April 2009 through April 2024. Patients with radiographic findings of an LSTV and clinical presentation underwent diagnostic injections to confirm diagnosis of Bertolotti's syndrome. Treatment was determined based on patient's LSTV classification. 157 patients with confirmed Bertolotti's syndrome underwent surgical treatment. Results. Over 500 patients presented with an appropriate clinical presentation and radiographic findings of an LSTV. Diagnostic injections were targeted into the transitional anatomy confirming the LSTV as the primary pain generator to make the diagnosis of Bertolotti's syndrome. The decision in the type of surgical intervention, resection or fusion, was made based on patient's LSTV anatomy. 157 patients with confirmed Bertolotti's Syndrome underwent surgical treatment (121 fusions (77%), 36 resections (23%)). The classification system and surgical outcomes, in part, have been previously published in World Neurosurgery. Conclusion. We have outlined the best practice of diagnosis and treatment selection for Bertolotti's syndrome. We have shown significant improvement in outcomes based on this method. We hope to aid in both patient education and provide an outline on how clinicians can become knowledgeable on Bertolotti's syndrome. Conflicts of interest. No conflicts of interest. Sources of funding. No funding obtained