Impact of mental health components on the development of back pain in young adults with adolescent idiopathic scoliosis.

BACKGROUND: Back pain occurs commonly in adults and is multifactorial in nature. This study aimed to assess the prevalence and intensity of back pain during young adulthood in subjects with adolescent idiopathic scoliosis (AIS), as well as factors that may be associated with its prognosis. METHODS: Subjects with AIS aged 20-39 treated conservatively were included in this study. Patient-reported outcome measures in adulthood involved episodes of back pain, and scales of self-image, depression, anxiety, and stress. Additionally, pain, self-image, and mental health scores were retrieved at the first clinic consultation. Occurrence of back pain was defined as a numeric pain rating scale ≥ 6. RESULTS: 101 participants were enrolled. The prevalence of back pain in the lifetime, past 12 months, past 6 months, past 1 month, past 7 days, and past 24 h were 37%, 35%, 31%, 27%, 23%, and 20%, respectively. Male, self-image, and depression were significant associated factors for the development of back pain at all time points. Furthermore, the analyses of the initial presentation of participants have shown that participants with back pain in adulthood were characterised by poor self-image and mental health during their adolescence. CONCLUSION: The present study addressed the natural history of back pain in young adults with conservatively treated AIS. Psychological makeup has been shown to constitute the development of back pain and is strongly hinted as an early sign of having back pain in adulthood among subjects with AIS.

Learning-based fully automated prediction of lumbar disc degeneration progression with specified clinical parameters and preliminary validation.

BACKGROUND: Lumbar disc degeneration (LDD) may be related to aging, biomechanical and genetic factors. Despite the extensive work on understanding its etiology, there is currently no automated tool for accurate prediction of its progression. PURPOSE: We aim to establish a novel deep learning-based pipeline to predict the progression of LDD-related findings using lumbar MRIs. MATERIALS AND METHODS: We utilized our dataset with MRIs acquired from 1,343 individual participants (taken at the baseline and the 5-year follow-up timepoint), and progression assessments (the Schneiderman score, disc bulging, and Pfirrmann grading) that were labelled by spine specialists with over ten years clinical experience. Our new pipeline was realized by integrating the MRI-SegFlow and the Visual Geometry Group-Medium (VGG-M) for automated disc region detection and LDD progression prediction correspondingly. The LDD progression was quantified by comparing the Schneiderman score, disc bulging and Pfirrmann grading at the baseline and at follow-up. A fivefold cross-validation was conducted to assess the predictive performance of the new pipeline. RESULTS: Our pipeline achieved very good performances on the LDD progression prediction, with high progression prediction accuracy of the Schneiderman score (Accuracy: 90.2 ± 0.9%), disc bulging (Accuracy: 90.4% ± 1.1%), and Pfirrmann grading (Accuracy: 89.9% ± 2.1%). CONCLUSION: This is the first attempt of using deep learning to predict LDD progression on a large dataset with 5-year follow-up. Requiring no human interference, our pipeline can potentially achieve similar predictive performances in new settings with minimal efforts.

Reliability of a three-dimensional spinal proprioception assessment for patients with adolescent idiopathic scoliosis.

PURPOSE: Although it is evident that some patients with adolescent idiopathic scoliosis (AIS) have proprioceptive deficit in peripheral joints, knowledge on the proprioceptive function of the deformed spine is limited. Nonetheless, spinal proprioception in AIS may be affected three-dimensionally, prior studies only focussed on evaluating peripheral proprioception in single plane. Therefore, this study aimed to develop a novel spinal proprioception assessment using three-dimensional motion analysis in patients with AIS. METHODS: Participants were included if they had a primary diagnosis of AIS who did not receive or failed conservative treatments. Three trunk repositioning tests involving flexion-extension, lateral-flexion, and axial-rotation were conducted. A three-dimensional kinematics of the trunk was used as the outcome measures. The proprioceptive acuity was quantified by the repositioning error. The intra-examiner and test-retest reliability were analysed by the intraclass correlation coefficient (ICC). RESULTS: Fifty-nine patients with AIS were recruited. Regarding the trunk flexion-extension test, the single measure ICC showed moderate reliability (0.46) and the average measures ICC demonstrated good reliability (0.72). As for the trunk lateral-flexion test, the reliability of single measure and average measures ICC was moderate (0.44) and good (0.70) reliability, respectively. For the trunk axial-rotation test, the single measure ICC indicated fair reliability (0.32), while the average measures ICC showed moderate reliability (0.59). CONCLUSION: This is the first study to evaluate the reliability of novel three-dimensional spinal proprioception assessments in patients with AIS. The trunk flexion-extension repositioning test may be preferable clinical test given its highest reliability.

Are Higher Global Alignment and Proportion Scores Associated With Increased Risks of Mechanical Complications After Adult Spinal Deformity Surgery? An External Validation.

BACKGROUND: The Global Alignment and Proportion (GAP) score, based on pelvic incidence-based proportional parameters, was recently developed to predict mechanical complications after surgery for spinal deformities in adults. However, this score has not been validated in an independent external dataset. QUESTIONS/PURPOSES: After adult spinal deformity surgery, is a higher GAP score associated with (1) an increased risk of mechanical complications, defined as rod fractures, implant-related complications, proximal or distal junctional kyphosis or failure; (2) a higher likelihood of undergoing revision surgery to treat a mechanical complication; and (3) is a lower (more proportioned) GAP score category associated with better validated outcomes scores using the Oswestry Disability Index (ODI), Scoliosis Research Society-22 (SRS-22) and the Short Form-36 questionnaires? METHODS: A total of 272 patients who had undergone corrective surgeries for complex spinal deformities were enrolled in the Scoli-RISK-1 prospective trial. Patients were included in this secondary analysis if they fulfilled the original inclusion criteria by Yilgor et al. From the original 272 patients, 14% (39) did not satisfy the radiographic inclusion criteria, the GAP score could not be calculated in 14% (37), and 24% (64) did not have radiographic assessment at postoperative 2 years, leaving 59% (159) for analysis in this review of data from the original trial. A total of 159 patients were included in this study,with a mean age of 58 ± 14 years at the time of surgery. Most patients were female (72%, 115 of 159), the mean number of levels involved in surgery was 12 ± 4, and three-column osteotomy was performed in 76% (120 of 159) of patients. The GAP score was calculated using parameters from early postoperative radiographs (between 3 and 12 weeks) including pelvic incidence, sacral slope, lumbar lordosis, lower arc lordosis and global tilt, which were independently obtained from a computer software based on centralized patient radiographs. The GAP score was categorized as proportional (scores of 0 to 2), moderately disproportional (scores of 3 to 6), or severely disproportional (scores higher than 7 to 13). Receiver operating characteristic area under curve (AUC) was used to assess associations between GAP score and risk of mechanical complications and risk of revision surgery. An AUC of 0.5 to 0.7 was classified as "no or low associative power", 0.7 to 0.9 as "moderate" and greater than 0.9 as "high". We analyzed differences in validated outcome scores between the GAP categories using Wilcoxon rank sum test. RESULTS: At a minimum of 2 years' follow-up, a higher GAP score was not associated with increased risks of mechanical complications (AUC = 0.60 [95% CI 0.50 to 0.70]). A higher GAP score was not associated with a higher likelihood of undergoing a revision surgery to treat a mechanical complication (AUC = 0.66 [95% 0.53 to 0.78]). However, a moderately disproportioned GAP score category was associated with better SF-36 physical component summary score (36 ± 10 versus 40 ± 11; p = 0.047), better SF-36 mental component summary score (46 ± 13 versus 51 ± 12; p = 0.01), better SRS-22 total score (3.4 ± 0.8 versus 3.7 ± 0.7, p = 0.02) and better ODI score (35 ± 21 versus 25 ± 20; p = 0.003) than severely disproportioned GAP score category. CONCLUSION: Based on the findings of this external validation study, we found that alignment targets based on the GAP score alone were not associated with increased risks of mechanical complications and mechanical revisions in patients with complex adult spinal disorders. Parameters not included in the original GAP score needed to be considered to reduce the likelihood of mechanical complications. LEVEL OF EVIDENCE: Level III, diagnostic study.

The first magnetically controlled growing rod (MCGR) in the world - lessons learned and how the identified complications helped to develop the implant in the past decade: case report.

BACKGROUND: The first magnetically controlled growing rod (MCGR) was implanted in 2009. Since then multiple complications have been identified that have helped drive the development of the MCGR and its surgery. The aim of this report is to illustrate how identified complications in the first MCGR helped with developments in the past decade and to report a unique failure mechanism with stud fracture close to the barrel opening. CASE PRESENTATION: A 5-year old girl with a scoliosis of 58.5 degrees at T1-9 and 72.8 degrees at T9-L4 had a single MCGR inserted and anchored at T3-4 and L3-4. At postoperative 13 months the MCGR was noted to have lost of distraction between lengthening episodes due to unrestricted turning of the internal magnet. To prevent further loss of distraction, an external magnet was placed outside the skin to prevent the magnet from turning back. The overall balance was suboptimal and after the rod was fully distracted, proximal junctional kyphosis occurred. Subsequently, the MCGR was modified with an internal keeper plate to prevent loss of distraction and a dual set of these rods were implanted when the patient was 9 years old. Extension proximally to C7-T1 was done to manage the proximal junctional kyphosis. Her spinal balance improved and distractions continued. She subsequently developed add-on below and the piston rod was not aligned with the actuator. The lumbar spine was also observed to have autofusion. She subsequently had final fusion surgery performed at the age of 15 from C7-L4 leaving a residual tilt below to avoid fusion to the pelvis. The final extracted rod on the left side indicated the "crooked rod sign" on X-ray and rod dissections revealed a new failure mechanism of stud fracture close to the barrel opening. Body fluids and tissue may infiltrate the rod despite no obvious deformation or fractures resulting in hastened wearing of the threads. CONCLUSIONS: There are various complications associated with MCGRs that are related to rod design and surgical inexperience. Repeated rod stalling is not recommended with potential stud fracture and "crooked rod sign". Rotor stalling and thread wearing which indicates rod failure still require solutions.

Multidisciplinary programme for rehabilitation of chronic low back pain - factors predicting successful return to work.

BACKGROUND: There are no clear indicators for predicting return to work for patients with chronic low back pain (LBP). We aim to report the outcomes of a 14-week multidisciplinary programme targeting patients with chronic LBP who failed conventional physiotherapy to provide functional rehabilitation. Also, this study will identify factors predicting successful return to work (RTW). METHODS: A collected cohort of patients with chronic LBP was consecutively enrolled into the programme from 1996 to 2014. All recruited patients failed to RTW despite at least 3 months of conservative treatment. Patient underwent weekly multidisciplinary sessions with physiotherapists, occupational therapists and clinical psychologists. Patient perceived function was considered the primary outcome of the programme. Patients were assessed for their sitting, standing and walking tolerance. Oswestry Disability Index (ODI) and Spinal Function Sort Score (SFSS) were used to assess patient perceived disability. RESULTS: One hundred and fifty-eight patients were recruited. After the programme, statistically significant improvement was found in ODI (47.5 to 45.0, p = 0.01) and SFSS (98.0 to 109.5, p <  0.001). There was statistically significant improvement (p <  0.01) in sitting, standing, walking tolerance and straight leg raise tests. 47.4% of the patients were able to meet their work demand. Multivariate logistic regression model (R2 = 59.5%, χ2 (9) = 85.640, p <  0.001) demonstrated that lower initial job demand level and higher patient-perceived back function correlated with greater likelihood of returning to work. CONCLUSION: The results of this study may support the use of this multidisciplinary programme to improve patient function and return to work.

Activating the unfolded protein response in osteocytes causes hyperostosis consistent with craniodiaphyseal dysplasia.

Bone remodeling is a balanced process between bone synthesis and degradation, maintaining homeostasis and a constant bone mass in adult life. Imbalance will lead to conditions such as osteoporosis or hyperostosis. Osteoblasts build bone, becoming embedded in bone matrix as mature osteocytes. Osteocytes have a role in sensing and translating mechanical loads into biochemical signals, regulating the differentiation and activity of osteoblasts residing at the bone surface through the secretion of Sclerostin (SOST), an inhibitor of WNT signaling. Excessive mechanical load can lead to activation of cellular stress responses altering cell behavior and differentiation. The unfolded protein response (UPR) is a shared pathway utilized by cells to cope with stress stimuli. We showed that in a transgenic mouse model, activation of the UPR in early differentiating osteocytes delays maturation, maintaining active bone synthesis. In addition, expression of SOST is delayed or suppressed; resulting in active WNT signaling and enhanced periosteal bone formation, and the combined outcome is generalized hyperostosis. A clear relationship between the activation of the unfolded protein response was established and the onset of hyperostosis that can be suppressed with a chemical chaperone, sodium 4-phenobutyrate (4-PBA). As the phenotype is highly consistent with craniodiaphyseal dysplasia (CDD; OMIM 122860), we propose activation of the UPR could be part of the disease mechanism for CDD patients as these patients are heterozygous for SOST mutations that impair protein folding and secretion. Thus, therapeutic agents ameliorating protein folding or the UPR can be considered as a potential therapeutic treatment.

Non-neurologic adverse events after complex adult spinal deformity surgery: results from the prospective, multicenter Scoli-RISK-1 study.

PURPOSE: Accurate information regarding the expected complications of complex adult spinal deformity (ASD) is important for shared decision making and informed consent. The purpose of the present study was to investigate the rate and types of non-neurologic adverse events after complex ASD surgeries, and to identify risk factors that affect their occurrence. METHODS: The details and occurrence of all non-neurologic adverse events were reviewed in a prospective cohort of 272 patients after complex ASD surgical correction in a mulitcentre database of the Scoli-RISK-1 study with a planned follow-up of 2 years. Logistic regression analyses were used to identify potential risk factors for non-neurologic adverse events. RESULTS: Of the 272 patients, 184 experienced a total of 515 non-neurologic adverse events for an incidence of 67.6%. 121 (44.5%) patients suffered from more than one adverse event. The most frequent non-neurologic adverse events were surgically related (27.6%), of which implant failure and dural tear were most common. In the unadjusted analyses, significant factors for non-neurologic adverse events were age, previous spine surgery performed, number of documented non-neurologic comorbidities and ASA grade. On multivariable logistic regression analysis, previous spine surgery was the only independent risk factor for non-neurologic adverse events. CONCLUSIONS: The incidence of non-neurologic adverse events for patients undergoing corrective surgeries for ASD was 67.6%. Previous spinal surgery was the only independent risk factor predicting the occurrence of non-neurologic adverse events. These findings complement the earlier report of neurologic complications after ASD surgeries from the Scoli-RISK-1 study. These slides can be retrieved under Electronic Supplementary Material.

A randomized double-blinded clinical trial to evaluate the safety and efficacy of a novel superelastic nickel-titanium spinal rod in adolescent idiopathic scoliosis: 5-year follow-up.

PURPOSE: To evaluate the safety and efficacy of a superelastic shape-memory alloy (SNT) rod used in the treatment of adolescent idiopathic scoliosis (AIS). METHODS: AIS Patients with Lenke 1 curves undergoing fusion surgery were randomized (1:1) at the time of surgery to receive either the SNT or a conventional titanium alloy (CTA) rod. Radiographs were obtained preoperatively and postoperatively up to 5 years of follow-up. Parameters assessed included coronal and sagittal Cobb angles, and overall truncal and shoulder balance. Sagittal profiles were subcategorized into Types A (<20°), B (20-40°), and C (>40°). RESULTS: Twenty-four patients with mean age of 15 years were recruited. A total of 87.0% of subjects were followed up till postoperative 5 years, but all patients had minimum 2 years of follow-up. The fulcrum-bending correction index for the SNT group was 113% at postoperative day 4 and 127% at half-year, while the CTA group was 112% at postoperative day 4 and only 106% at half-year. In terms of sagittal profile, the SNT group moved toward type B profile at half-year follow-up with a mean correction of 7.6°, while no significant change was observed in the CTA group (-0.7°). Nickel levels remained normal, and there were no complications. CONCLUSIONS: This is the first randomized clinical trial of a novel SNT rod for treating patients with AIS, noting it to be safe and has potential to gradually correct scoliosis over time. This study serves as a pilot and platform to properly power future large-scale studies to demonstrate efficacy and superiority.

Ten year follow-up of Jarcho-Levin syndrome with thoracic insufficiency treated by VEPTR and MCGR VEPTR hybrid.

PURPOSE: Jarcho-Levin syndrome patients commonly suffer from repeated respiratory infections and become ventilator dependent due to an insufficient thoracic volume. Multiple congenital vertebral anomalies are associated with this genetic disorder and results in stunted spine growth. The purpose of this case report is to present the results of a hybrid vertical expandable prosthetic titanium rib (VEPTR) and magnetically controlled growing rod (MCGR) construct for the management of a patient with Jarcho-Levin syndrome. METHODS: A boy with Jarcho-Levin syndrome undergoes a hybrid VEPTR-MCGR construct to treat his thoracic insufficiency syndrome and spinal deformity. RESULTS: The patient could wean off ventilator and had reduced chest complications with the construct. He was also able to achieve some spine length gain with the distraction device. However, there were limitations in prolonged treatment as no spine height was gained once he reached 12 years old. Once no further growth can be achieved, the MCGR led to progressive kyphosis. Nevertheless, at latest follow-up after the removal of all implants, the patient could maintain satisfactory correction of both thoracic and spine deformities. CONCLUSIONS: A hybrid construct is necessary for managing Jarcho-Levin syndrome as the VEPTR deals with the thoracic cage deformity while the MCGR deals with the spine deformity.

A rare postoperative complication of anterior lower thoracic instrumentation: diaphragmatic laceration with hemothorax.

PURPOSE: To highlight the importance of preventing visceral injury due to prominent anterior implants at the spinal column. METHODS: A 52-year-old man with cord compression was treated with a T9/10 discectomy and instrumented fusion via a right thoracotomy and trans-pleural approach. Postoperatively, he had improved lower limb numbness. However, after a bout of coughing, there was sudden increase in chest drain output, hemodynamic instability and massive fluid collection in the right chest cavity. RESULTS: Emergency re-exploration of the thoracotomy was performed and a 6 cm laceration of the right postero-medial diaphragm was identified as the bleeding source and was found to be in close proximity with the locking nut of the anterior implants. The laceration was repaired and a soft synthetic patch was used to cover the implants. Postoperatively, the hemothorax resolved and the patient recovered from the neurological deficit. CONCLUSIONS: Prevention of diaphragmatic injury can be performed using lower profile and less sharp-edged implants. Implant coverage with a soft synthetic material is necessary if unable to perform direct repair of the parietal pleura over the implants.

Predictive factors for neurological deterioration after surgical decompression for thoracic ossified yellow ligament.

PURPOSE: To investigate the rate and predictive factors of post-operative neurological deterioration in ossified yellow ligament (OYL) surgery. METHODS: A retrospective review was conducted for all patients with thoracic OYL causing myelopathy requiring surgical decompression from January 1998 to December 2012. Clinical parameters under study included clinical presentation, distribution of OYL, pre-operative walking score, pre- and post-operative neurological status, status of intra-operative neurophysiological monitoring, and modified Japanese Orthopaedic Association (mJOA) score. Any complications were also recorded. All outcomes were measured at post-operative 1 week and at 2 years. RESULTS: A total of 26 patients were included in this study. Most patients (92.3%) had Frankel grade D pre-operatively. The rate of neurological deterioration was 15.4% and was correlated with the presence of dural tear, extra-dural hematoma and spinal cord injury. Pre-operative walking score was prognostic of patients' walking ability in the post-operative period. Intra-operative monitoring of Somatosensory Evoked Potentials (SSEP) was found to be useful for monitoring spinal cord injury in OYL surgery, with a positive predictive value of 100% and a negative predictive value of 92.3%. The false negative rate of a SSEP signal drop was only 7.7% CONCLUSIONS: This is the first study exploring risk factors for post-operative neurological deterioration after surgery for thoracic OYL. The rate of neurological deficit is not small and prognostic factors for poor outcome include poor pre-operative walking score, presence of intra-operative dural tear, extra-dural hematoma and spinal cord injury, and intra-operative drop of SSEP signal.

Use of PET/CT in the early diagnosis of implant related wound infection and avoidance of wound debridement.

PURPOSE: Delayed infections after spinal instrumentation typically require complete implant removal and extensive wound debridement due to the difficulties in establishing an early diagnosis. We report a case of occult late infection after posterior spinal instrumentation that was detected early using PET/CT and therefore was successfully treated with antibiotics alone. METHODS: A 26-year-old woman who underwent posterior spinal instrumentation and fusion for scoliosis correction had superficial pseudomonal infection that healed with ceftazidime and levofloxacin and was admitted 4 months later with mild back pain. She had no fever and the surgical wound healed well. Laboratory tests were compatible with late infection but radiographs showed no signs of implant infection. The patient was suspected of having ongoing occult late infection and thus, underwent a PET/CT. RESULTS: PET/CT revealed a significant pathological FDG uptake at the T5 vertebral body and the area surrounding proximal end of the T5 instrumentation. The maximal standardized uptake value (SUV) was 7.9 for the T5 vertebra and only 2.3 for the patient's liver, suggesting an infection pathology. A conclusive diagnosis of delayed onset infection after spinal instrumentation was established and the patient was immediately started on oral anti-pseudomonal treatment. The scoliosis correction was well maintained 10 months after the index surgery and she had no signs of implant infection. CONCLUSIONS: PET/CT provides detailed diagnostic information for occult infections in the absence of morphological changes and thus, is valuable for an early diagnosis of late infection after spinal instrumentation. It is possible to retain the instrumentation in the case of late infection, if early detection and efficacious treatment can be achieved timely.

Antimicrobial prophylaxis to prevent surgical site infection in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion: 2 doses versus antibiotics till drain removal.

PURPOSE: There is much variation in the choice, timing and duration of antimicrobial prophylaxis for preventing surgical site infections (SSI) but no guideline exists for scoliosis surgery. The aim of study was to compare the efficacy of two antimicrobial prophylaxis (AMP) protocols with cephazolin in preventing SSI in adolescent idiopathic scoliosis (AIS). METHODS: A retrospective comparative analysis of two post-operative AMP protocols (two postoperative doses versus continued antibiotics till drain removal) was performed. Patient characteristics, pre-operative, intra- and post-operative risk factors for infection, drain use, generic drug name and number of doses administered were recorded from 226 patients with AIS who had undergone posterior spinal fusion. Details of superficial or deep SSI and wound healing aberrations, and serious adverse events were recorded. Analysis was performed to evaluate differences in the pre-, intra- and post-operative variables between the two groups. RESULTS: 155 patients received 2 postoperative doses of AMP and 71 patients had antibiotics till drain removal. The average follow-up was 43 months. The overall rate of SSI was 1.7 % for the spine wound and 1.3 % for the iliac crest wound. 1.9 % of patients with 2 doses of AMP and 1.4 % of patients with antibiotics till drain removal had SSI. No adverse reactions attributable to cephazolin were observed. CONCLUSIONS: This is the first study on the AMP protocol in scoliosis surgery for SSI prevention. Results suggest that two doses of AMP are as effective as continued antimicrobial use until drain removal. Cephazolin appears to be effective and safe for prophylaxis.

Incidence of back pain from initial presentation to 3 years of follow-up in subjects with untreated adolescent idiopathic scoliosis.

BACKGROUND: Although back pain may be present in subjects with adolescent idiopathic scoliosis (AIS), its natural history is unknown. Therefore, this study evaluated the incidence of back pain in scoliotic adolescents longitudinally. METHODS: This retrospective analysis examined prospectively collected pain subscale data of the Scoliosis Research Society questionnaire between the initial presentation and up to 3 years of follow-up. Consecutive subjects with AIS aged 10-18 at baseline managed by observation within the study period were included. Study subjects with at least one time point of follow-up data were considered. Alternatively, a group with physiotherapy-treated was also included for comparison. RESULTS: We enrolled 428 subjects under observation. The incidence of back pain among study subjects was 14.7%, 18.8%, and 19.0% for the first year, second year, and third year of follow-up, respectively. Most experienced mild pain (1 out of 5 points) throughout the study. Neither incidence nor intensity of pain significantly differed between subjects under observation and received physiotherapy. Additionally, study subjects with a new onset of back pain had poorer function, self-image, and mental health scores than those without pain. CONCLUSION: We investigated the incidence of back pain longitudinally in subjects suffering from AIS. Further validation of the current results is warranted.

Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series.

BACKGROUND: Scoliosis in skeletally immature children is often treated by implantation of a rod to straighten the spine. Rods can be distracted (lengthened) as the spine grows, but patients need many invasive operations under general anaesthesia. Such operations are costly and associated with negative psychosocial outcomes. We assessed the effectiveness and safety of a new magnetically controlled growing rod (MCGR) for non-invasive outpatient distractions. METHODS: We implanted the MCGR in five patients, two of whom have now reached 24 months' follow-up. Each patient underwent monthly outpatient distractions. We used radiography to measure the magnitude of the spinal curvature, rod distraction length, and spinal length. We assessed clinical outcome by measuring the degree of pain, function, mental health, satisfaction with treatment, and procedure-related complications. FINDINGS: In the two patients with 24 months' follow-up, the mean degree of scoliosis, measured by Cobb angle, was 67° (SD 10°) before implantation and 29° (4°) at 24 months. Length of the instrumented segment of the spine increased by a mean of 1·9 mm (0·4 mm) with each distraction. Mean predicted versus actual rod distraction lengths were 2·3 mm (1·2 mm) versus 1·4 mm (0·7 mm) for patient 1, and 2·0 mm (0·2 mm) and 2·1 mm (0·7 mm) versus 1·9 mm (0·6 mm) and 1·7 mm (0·8 mm) for patient 2's right and left rods, respectively. Throughout follow-up, both patients had no pain, had good functional outcome, and were satisfied with the procedure. No MCGR-related complications were noted. INTERPRETATION: The MCGR procedure can be safely and effectively used in outpatient settings, and minimises surgical scarring and psychological distress, improves quality of life, and is more cost-effective than is the traditional growing rod procedure. The technique could be used for non-invasive correction of abnormalities in other disorders. FUNDING: Ellipse Technologies.

Percutaneous endoscopic lumbar discectomy in lumbar disc herniation with posterior ring apophysis fracture: A case report in a 15-year-old child.

RATIONALE: Lumbar disc herniation (LDH) with posterior ring apophysis fracture (PRAF) is rather rare in children, and in all age-stratified LDH patients, the incidence of RAF was 5.3% to 7.5%. Interestingly, the incidence of LDH with RAF in children (15%-32%) is several times higher than in adults, the mis-diagnosis of which may lead to delayed treatment. PATIENT CONCERNS: Here, we report a 15-year-old schoolboy who suffered from sudden low back pain and radiating pain in both lower limbs after sport activities. Symptoms persisted after 3 months of conservative treatment. Computer radiography and magnetic resonance imaging indicated central disc herniation with PRAF at L4-5. DIAGNOSIS: LDH with PRAF. INTERVENTIONS: The herniated disc and epiphyseal fragments were successfully excised by the percutaneous endoscopic lumbar discectomy minimal-invasive technique. OUTCOMES: Surgery was successful. Symptoms were immediately relieved postoperatively with a wound of only about 7.0 mm. Discharged on the next day. No perioperative complications occurred. Moreover, the imaging and clinical outcomes were also more satisfactory during the post-operative 15 months outpatient follow-up. LESSONS: Pediatric LDH with PRAF is extremely uncommon, and there is a lack of training among physicians for such cases, which may lead to delayed diagnosis and treatment. Once a diagnosis for LDH with PRAF is established, percutaneous endoscopic lumbar discectomy is a safe and effective minimally invasive treatment to be considered, and we hope that this technique can provide more assistance in the future.

Mechanical characterization and design of biomaterials for nucleus pulposus replacement and regeneration.

Biomaterials for nucleus pulposus (NP) replacement and regeneration have great potential to restore normal biomechanics in degenerated intervertebral discs following nucleotomy. Mechanical characterizations are essential for assessing the efficacy of biomaterial implants for clinical applications. While traditional compression tests are crucial to quantify various modulus values, relaxation behaviors and fatigue resistance, rheological measurements should also be conducted to investigate the viscoelastic properties, injectability, and overall stability upon deformation. To recapitulate the physiological in vivo environment, the use of spinal models is necessary to evaluate the risk of implant extrusion and the restoration of biomechanics under different loading conditions. When designing devices for NP replacement, injectable materials are ideal to fully fill the nucleus cavity and prevent implant migration. In addition to achieving biocompatibility and desirable mechanical characteristics, biomaterial implants should be optimized to avoid implant extrusion or re-herniation post-operatively. This review discusses the most commonly used testing protocols for assessing mechanical properties of biomaterial implants and serves as reference material for enabling researchers to characterize NP implants through a unified approach whereby newly developed biomaterials may be compared and contrasted to existing devices.

An intelligent composite model incorporating global / regional X-rays and clinical parameters to predict progressive adolescent idiopathic scoliosis curvatures and facilitate population screening.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) affects up to 5% of the population. The efficacy of school-aged screening remains controversial since it is uncertain which curvatures will progress following diagnosis and require treatment. Patient demographics, vertebral morphology, skeletal maturity, and bone quality represent individual risk factors for progression but have yet to be integrated towards accurate prognostication. The objective of this work was to develop composite machine learning-based prediction model to accurately predict AIS curves at-risk of progression. METHODS: 1870 AIS patients with remaining growth potential were identified. Curve progression was defined by a Cobb angle increase in the major curve of ≥6° between first visit and skeletal maturity in curves that exceeded 25°. Separate prediction modules were developed for i) clinical data, ii) global/regional spine X-rays, and iii) hand X-rays. The hand X-ray module performed automated image classification and segmentation tasks towards estimation of skeletal maturity and bone mineral density. A late fusion strategy integrated these domains towards the prediction of progressive curves at first clinic visit. FINDINGS: Composite model performance was assessed on a validation cohort and achieved an accuracy of 83.2% (79.3-83.6%, 95% confidence interval), sensitivity of 80.9% (78.2-81.9%), specificity of 83.6% (78.8-84.1%) and an AUC of 0.84 (0.81-0.85), outperforming single modality prediction models (AUC 0.65-0.78). INTERPRETATION: The composite prediction model achieved a high degree of accuracy. Upon incorporation into school-aged screening programs, patients at-risk of progression may be prioritized to receive urgent specialist attention, more frequent follow-up, and pre-emptive treatment. FUNDING: Funding from The Society for the Relief of Disabled Children was awarded to GKHS.

Application of silver nanoparticles for improving motor recovery after spinal cord injury via reduction of pro-inflammatory M1 macrophages.

Silver nanoparticles (AgNPs) possess anti-inflammatory activities and have been widely deployed for promoting tissue repair. Here we explored the efficacy of AgNPs on functional recovery after spinal cord injury (SCI). Our data indicated that, in a SCI rat model, local AgNPs delivery could significantly recover locomotor function and exert neuroprotection through reducing of pro-inflammatory M1 survival. Furthermore, in comparison with Raw 264.7-derived M0 and M2, a higher level of AgNPs uptake and more pronounced cytotoxicity were detected in M1. RNA-seq analysis revealed the apoptotic genes in M1 were upregulated by AgNPs, whereas in M0 and M2, pro-apoptotic genes were downregulated and PI3k-Akt pathway signaling pathway was upregulated. Moreover, AgNPs treatment preferentially reduced cell viability of human monocyte-derived M1 comparing to M2, supporting its effect on M1 in human. Overall, our findings reveal AgNPs could suppress M1 activity and imply its therapeutic potential in promoting post-SCI motor recovery.