Objective: Facet joints are crucial for spinal stability but develop premature osteoarthritis in patients with adolescent idiopathic scoliosis (AIS). Here, we evaluated the association between facet joint cartilage and subchondral bone homeostasis, perceived back pain and 3-dimensional spinal deformity to better understand the role of facet joint degeneration in AIS progression and pain.Method: The osteoarthritic state of cartilage and bone of AIS facet joint surgical samples were characterized using histological OARSI scoring, visual morphological grading and mCT analysis, respectively. Back pain was self-reported using a numerical rating scale and expressed relative to the location on the patient's back. The scoliotic curves from our patient cohort were digitally reconstructed using biplanar radiographs and the eOS system (EOS imaging). The deformity was then reduced to three intervertebral angles (coronal, sagittal and axial) for each pair of bilateral facet joints. Statistical associations between the intervertebral angles, osteoarthritis parameters and pain intensity were performed using the Spearman method and Friedman test.Results: Facet joint cartilage degeneration was associated with decreased subchondral bone volume and quality. Most importantly, asymmetrical, and overall degeneration of facet joints was strongly correlated to intervertebral axial rotation. Additionally, kyphotic intervertebral segments in the sagittal plane were good predictors of increased facet joint degeneration and back pain.Conclusion: Facet joint degeneration is associated with axial deformity, kyphotic intervertebral angle and back pain intensity in AIS. These results suggest that facet joints are important features to consider for rotational instability in AIS spines and related disease progression and perceived back pain.& COPY; 2023 Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International.

Purpose: Quantitative sensory testing (QST) is a standardized method to assess somatosensory function.The collection of qualitative information, during the QST procedure, could be an interesting way to facilitate the characterization of altered sensory perception and the identification of different pain phenotypes.The aims of this study were 1) to classify qualitative fieldnotes of sensory abnormalities collected during an independent QST study, and 2) to generate a qualitative interview guide that could be included in the traditional QST procedure as a step towards the implementation of a mixed methods approach.Patients and Methods: QST data were collected from 48 chronic neuropathic pain patients treated with spinal cord stimulation (SCS).Three body areas, with or without SCS, were tested: the painful limb targeted by SCS, the contralateral area, and the ipsilateral upper limb.After each trial of each QST modality, patients were encouraged to report any sensory abnormalities they could identify with a pain quality scale or using their own words.Results: Qualitative self-reported sensory abnormalities were dichotomized into two groups: altered sensory intensities and altered sensory perceptions.Altered sensory intensities were classified as sensory loss or sensory gain subgroups.Altered sensory perceptions were classified as paresthesia and dysesthesia subgroups Overall, 630 qualitative fieldnotes of altered sensations were collected: 385 on the painful limb, 173 at the contralateral area, and 72 at the ipsilateral upper limb.Based on these qualitative data, we propose a standardized method to collect qualitative data involving 9 open-and close-ended questions and 21 codes.Conclusion: Our findings have highlighted the value of qualitative sensory evaluation during QST and constitute an important milestone in the development of a mixed methods protocol in phenotyping research.

The days following surgery encompass a critical period where the use of opioids predicts long-term outcomes in adults. It is currently unknown as to whether opioid consumption throughout the acute postoperative period is associated with long-term outcomes in pediatric patients. The aims of this study were to characterize opioid trajectories in the acute postoperative period, identify predictors of opioid trajectory membership and determine associations between opioid trajectories and long-term patient outcomes. Medication use, pain and mental health status were assessed at baseline in adolescents with idiopathic scoliosis who were schedule for spinal fusion surgery. Cumulative 6-hour opioid consumption was recorded for up to 5 days after spinal surgery. At 6 weeks and 6 months after surgery, medication use, pain and physical function were evaluated. Growth mixture modeling was used to identify opioid trajectories. The study included 106 patients. Mean cumulative opioid consumption in the acute postoperative period was 13.23 ± 5.20 mg/kg. The model with the best fit contained 5 acute postoperative opioid trajectories and a quadratic term (AIC = 6703.26, BIC = 6767.19). Opioid trajectories differed in the total amount of opioids consumed and the rate of opioid intake over the acute postoperative period. Intraoperative epimorphine dose predicted the opioid trajectory membership (p = 0.0498). Opioid trajectory groups were significantly associated with pain at 6 weeks (p = 0.0103) and 6 months (p = 0.0457) after surgery. Intraoperative epimorphine dose predicts the opioid consumption in the acute postoperative period. Opioid consumption during this period is associated with long-term pain. Understanding the acute postoperative period and its association with baseline predictors and long-term patient outcomes will allow for personalized perioperative care. The days following surgery encompass a critical period where the use of opioids predicts long-term outcomes in adults. It is currently unknown as to whether opioid consumption throughout the acute postoperative period is associated with long-term outcomes in pediatric patients. The aims of this study were to characterize opioid trajectories in the acute postoperative period, identify predictors of opioid trajectory membership and determine associations between opioid trajectories and long-term patient outcomes. Medication use, pain and mental health status were assessed at baseline in adolescents with idiopathic scoliosis who were schedule for spinal fusion surgery. Cumulative 6-hour opioid consumption was recorded for up to 5 days after spinal surgery. At 6 weeks and 6 months after surgery, medication use, pain and physical function were evaluated. Growth mixture modeling was used to identify opioid trajectories. The study included 106 patients. Mean cumulative opioid consumption in the acute postoperative period was 13.23 ± 5.20 mg/kg. The model with the best fit contained 5 acute postoperative opioid trajectories and a quadratic term (AIC = 6703.26, BIC = 6767.19). Opioid trajectories differed in the total amount of opioids consumed and the rate of opioid intake over the acute postoperative period. Intraoperative epimorphine dose predicted the opioid trajectory membership (p = 0.0498). Opioid trajectory groups were significantly associated with pain at 6 weeks (p = 0.0103) and 6 months (p = 0.0457) after surgery. Intraoperative epimorphine dose predicts the opioid consumption in the acute postoperative period. Opioid consumption during this period is associated with long-term pain. Understanding the acute postoperative period and its association with baseline predictors and long-term patient outcomes will allow for personalized perioperative care.

Chronic non-cancer pain in children and adolescents has been described as "a modern public health disaster" that has generated significant medical and economic burdens within society. Seen as a disease in its own right, chronic pain has short and long-term consequences that impact not only the patient's health but also that of friends and families, due to significant parenting stress and disruptions in family life and structure. The evidence supporting pharmacological treatments and interventional procedures is limited, and no single strategy has been shown to be completely effective in children with chronic non-cancer pain. Therefore, considering the multifactorial nature of chronic pain, these patients should be treated with a multidisciplinary, balanced approach that seeks a primary outcome of improved functioning rather than of pain reduction. Using a bio-psycho-social approach, a multidisciplinary team, including a physiotherapist, nurse, social worker, psychologist, and physician, has been effective in achieving this outcome of improved functioning in children and adolescents with chronic pain. In this review, we discuss the impact, associated conditions, and evolution of chronic pain, along with the crucial role of every member of a multidisciplinary chronic pain clinic involved in the care of the children and adolescents with chronic non-cancer pain.

Spinal fusion surgery with instrumentation is an invasive and extensive surgery that predisposes children to high risks of developing kinesiophobia (fear of movement) and consequent morbidities like disability. Currently, kinesiophobia is only reliably measured with a questionnaire. To improve recovery after surgery, an objective detection is needed. The aims of the study were to identify kinesiophobia with the Tampa Scale for Kinesiophobia (TSK) questionnaire and to detect kinesiophobia with an objective lumbar physical assessment, and to associate the objective tests to the subjective measures. Ten 10–19 year-old patients with Adolescent Idiopathic Scoliosis scheduled to undergo surgery were enrolled. Before and six weeks after surgery, patients answered the TSK questionnaire and performed a physical assessment comprised of a sit & reach, supine bridge and prone alternating arm & leg raises tests. Via objective grading component, a higher score indicated presence of kinesiophobia. Correlation, two-way ANOVA and paired t-tests analyses were performed. After surgery, an increase in subjective TSK (P = .05) and its sub-score activity avoidance (P = .03) was observed in comparison to before surgery. Objectively, a diminished physical performance was observed after surgery with the total score of all physical assessments (P < .01), and in the score for arm & leg raise (P < .01). An association of the physical assessment of kinesiophobia was observed with the TSK score when the cohort was divided according to the median score. The sub-group who performed worse after surgery was associated to having greater activity avoidance (P < .0001). Results suggest that a physical assessment performed in the clinic could help identify who is at risk of developing kinesiophobia after surgery.

Introduction Adolescent Idiopathic Scoliosis (AIS) has been thought to be a relatively painless three dimensional (3D) deformity of the spine, but some studies has shown that the incidence of mild to moderate pain in AIS ranges from 25 to 50%. With the arrival of the new low dose radiation EOS technology, it is now possible to quantify intersegmental changes of the scoliotic spine in an upright position that could be related to pain. Hypothesis EOS 3D morphological analysis of AIS patients will better correlate with presence of pain than the Lenke classification. Methods Fifty-nine patients (7 male/52 female, mean age of 14.3 years old) who were scheduled for elective posterior spinal fusion with diagnosis of AIS. Preoperative clinical pain data recorded consisted of: 1) numerical visual analogue (VAS) pain scores quantifying patients average and worst pain over the preceding month; 2) SRS22 scores. Preoperative PA and lateral imaging were utilized to reconstruct and generate 3D models using the EOS software. Global and segmental intervertebral orientation in all three planes including the Da Vinci diagram identifying maximal deformity orientation were generated and correlated with patients' clinical presentation. In addition, standard curve magnitude, curve classification (Lenke) and pelvic parameters were also analyzed to observe their association to pain. Statistical analysis was performed with GraphPad Prism 6. Results Lenke classification and its subtypes did not correlate with pain, nor did any of the classic curve parameters, with the exception of the presence of hyper lumbar lordosis (>60 degrees) (r = 0.32, p = 0.06). Hyperlordotic patients reported greater pain intensity than normal lordotic patients (U = 81.50, p = 0.04). Additional new 3D parameters from both global and intersegmental vertebral orientations in space were investigated. With the exception of high intervertebral frontal, lateral tilt of L4 over L5, no 3D correlations with pain patterns were observed. Conclusion Despite the additional 3D morphological analysis generated by the EOS imaging, we were not able to identify anatomical characteristics associated to the pain experience reported by patients, with the exception of hyperlumbar lordosis.

Introduction The purpose of the present study was to investigate if preoperative concentrations of monoamine neurotransmitters that are known to be involved in descending pain modulation are associated with perioperative pain intensity in a pediatric cohort of patients with idiopathic scoliosis scheduled for elective spinal fusion surgery. Material and Methods Patients scheduled to undergo spinal surgery for Adolescent Idiopathic Scoliosis (AIS) between the ages of 12 and 18 years were recruited from the outpatient clinic of the Shriners Hospital for Children ( n = 50). Plasmatic and cerebrospinal fluid concentrations of epinephrine (EPI), norepinephrine (NE), and their respective metabolite metanephrine (ME) and normetanephrine (NME), were assessed. Five mL of blood were collected for study analysis in an EDTA-coated collection tube after the anesthesia induction. Prior to the intratechal epimorphine injection, 2 mL of cerebrospinal fluid was collected in a low binding protein tube. Monoamine neurotransmitters were derivatized by reductive diethylation analyzed by liquid chromatography coupled with tandem mass spectrometry on TripleTOF 5600 mass spectrometer. At all time points throughout the study (preoperative, first postoperative 24 hours = postoperative day 1 (POD1), second 24 hours = postoperative day 2 (POD2) and postoperative 6 weeks follow-up visit), pain intensity was rated with the use of the Faces Pain Scale-Revised (FPS-R). Linear regressions were performed to assess the predictive role of catecholamine levels for postoperative pain. The Mann-Whitney-U test was used to assess differences in baseline characteristics between patients reporting presence of pain and pain-free patients as well as for all other comparisons other than correlations. Results Our results demonstrate that patients reporting persistent postsurgical pain 6 weeks after surgery have greater preoperative peripheral and/or central norepinephrine (NE) and normetanephrine levels when compared with patients reporting no pain at follow-up. Likewise, in the acute postoperative period, patients reporting moderate-to-severe pain intensity had higher preoperative central NE levels. Conclusion These results support the evidence for a potential role of catecholamine levels in predicting postoperative pain intensity and sympathetically maintained pain, which could place pediatric patients at risk for the development of chronic postsurgical pain. Incidence and severity of persistent postoperative pain may be reduced by specific NE preoperative interventions.

Pediatric pain management could be substantially improved by the existence of objective biomarkers that can guide treatment decision-making. The objective of this longitudinal observational investigation is to identify associations between the expression of pain-related biomarkers in physiological fluids and the experience of pain in a pediatric population in the peri-operative period. Study participants undergoing spinal surgery for adolescent idiopathic scoliosis completed validated pain questionnaires on the pre-operative consult visit (∼1 week pre-op), 48 hours post-surgery, and on their first post-operative visit (∼4 weeks post-op). During the pre-operative consult, saliva and blood samples were collected. Samples were also collected on the day of surgery, with the addition of a cerebrospinal fluid sample. Finally, saliva and blood samples were collected again 48 hours and 4 weeks post-surgery. Biomarkers were analyzed using commercially available ELISA kits according to the manufacturers’ instructions. The severity of the scoliosis was not related with post-operative pain at any time point or with any other psychosocial variables (P>0.05). Patients’ subjective pain report was significantly increased immediately after surgery but returned to pre-operative values within 4 weeks. Biomarker concentrations demonstrated variation over time such as significant increases in cortisol on the day of surgery and IL-6 up-regulation 48 hours post-surgery (P<0.05). Preliminary analysis suggests that high pre-operative concentrations of cortisol correlate to an increase in patient-controlled analgesia (PCA) attempts in the first 24 hours post-surgery. These preliminary results provide proof-of-concept that pre-operative biomarkers can predict post-operative pain management and validate our experimental approach for the identification of pain-specific biomarkers. Biomarker analysis may therefore provide a deeper understanding of a patient’s pain perception and potentially serve as objective quantitative predictors of children’s post-operative pain burden.

# 1.1.01 The use of suspension radiographs to predict LIV tilt. {#article-title-2} In adolescent idiopathic scoliosis (AIS) surgery the goal is to obtain a well-balanced correction of the spine while preserving as much mobility as possible. Due to the powerful effect of pedicle screw constructs in

Introduction Chronic low back pain (LBP) affects over 10% of the adult population resulting in profound decreases in the quality of life. The intervertebral disk (IVD) is prone to degeneration which may contribute toLBP. To prevent disk degeneration-related LBP, better understanding of disk structure and the degenerative process is needed to understand the underlying mechanisms. Standard Hematoxylin and Eosin (H&E) staining, alone or in combination with other dyes, have been used to assess the normal biology and degeneration of IVDs. Recently, the multichromatic FAST (Alcian blue, Safranin-O, Fast green and Tartrazine) staining method has been developed (Leung V.Y.L. et al., 2009). This method provides additional information unavailable through conventional methods such as differentiation of the structures within the disk and identification of degenerative matrix remodeling through changes in the staining pattern. Although the FAST method has proved helpful in animal models to assess alteration of glycosaminoglycan content, its usefulness to assess human disk histopathology remains unknown. Materials and Methods Human disks were obtained (a) surgically from chronic LBP patients with moderate-severe disk degeneration or (b) postmortem from transplant donors. Disks were cut into quadrants, fixed in 4% paraformaldehyde with 14% (v/v) saturated picric acid for 3 days, embedded in OCT and stored at −80°C. Tissue samples were cut on a cryostat and transverse sections of 14 um and 20 um were obtained for H&E and FAST staining, respectively. Slides were coverslipped with DPX and scanned using a Zeiss MIRAX Scan Digital Slide Scanner for further examination. Results The FAST protocol creates high-resolution and polychromatic images of the general disk structure, and reveals the overall organization of the disk. The transition from the nucleus pulposus (NP) to the inner annulus fibrosus (IAF) and the outer annulus fibrosus (OAF) was clearly visible through color boundaries. Signs of degeneration could be observed with the FAST staining method in both IVDs obtained postmortem with no history of LBP and from chronic LBP patients. For example, FAST staining uncovered the loss of a clear boundary between the NP and the IAF that was not visible with H&E. These data suggest that relevant pathological details might be missed if assessing histological changes with the use of H&E only. Conclusion The combined use of H&E and FAST methods provides a more complete picture of the anatomy and physiology of human IVDs. The FAST profile distinguishes IVD compartments and shows matrix remodeling events within the disk, while H&E provides complementary information regarding the cellular content of the tissue. These two staining methods complement each other to give a clearer differentiation of IVD sub-regions of both normal and degenerated disk architecture. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared Leung V.Y.L. et al. Journal of Histochemistry and Cytochemistry 2009;57:249

The purpose of this study was to compare the gait parameters recorded on the CatWalk and the mechanical sensitivity with von Frey filaments of two putative models of osteoarthritis over a one month period, and to evaluate the effect of celecoxib on these parameters. Animals underwent either a surgical sectioning of the anterior cruciate ligament with partial medial menisectomy (ACLT+pMMx) to create a joint instability model or received an intra-articular injection of monoiodoacetate (MIA) as a putative inflammatory joint pain model. Animals were assessed for four consecutive weeks and knee joints were then evaluated histologically. Spinal cord lumbar enlargements were harvested for selected neuropeptide analysis (substance P (SP) and calcitonin gene related peptide (CGRP)). With the MIA model, significant changes persisted in selected dynamic gait parameters throughout the study in the injured limb as well as with the von Frey filaments. The ACLT+pMMx model in contrast showed no clear differential response between both hind limb for both gait parameters and pain-related behavior with von Frey filaments occurred only on the last day of the study. Neuropeptide analysis of spinal cord lumbar enlargements revealed a significant increase in CGRP concentration in both models and an increase in SP concentration only in the MIA model. Histological evaluation confirmed the presence of articular cartilage lesions in both models, but they were much more severe in the MIA model. Celecoxib had an effect on all selected gait parameters at the very beginning of the study and had an important alleviating effect on mechanical allodynia. These results suggest that the MIA model may be more appropriate for the evaluation of short term pain studies and that celecoxib may modulate mechanical allodynia through central sensitization mechanisms.

We evaluated the effects of buprenorphine (0.05 mg/kg intraperitoneally) after collagenase-induced intracerebral hemorrhage in Sprague-Dawley rats. Methods of evaluation included serum biochemistry, behavioral tests (neurologic exam and rotarod treadmill), and histopathology. Serum biochemistry parameters showed no change after surgery in controls and buprenorphine-treated animals. At 48 h after collagenase injections, the performance of treated rats on the rotarod treadmill test was not significantly different from that of untreated rats, but the neurologic exams of treated rats showed significantly improved performance. Although the volume of the hematoma was reduced with buprenorphine, the number of necrotic neurons in the penumbra was significantly increased. These data indicate that administration of buprenorphine led to neurologic and histopathologic differences in a rat model of intracerebral hemorrhage, and data from such studies should be interpreted carefully if an opioid analgesic is used to minimize pain.