Early treatment of type II SMA slows rate of progression of scoliosis.

BACKGROUND: Type II spinal muscular atrophy (SMA) often leads to scoliosis in up to 90% of cases. While pharmacological treatments have shown improvements in motor function, their impact on scoliosis progression remains unclear. This study aims to evaluate potential differences in scoliosis progression between treated and untreated SMA II patients. METHODS: Treatment effect on Cobb's angle annual changes and on reaching a 50° Cobb angle was analysed in treated and untreated type II SMA patients with a minimum 1.5-year follow-up. A sliding cut-off approach identified the optimal treatment subpopulation based on age, Cobb angle and Hammersmith Functional Motor Scale Expanded at the initial visit. Mann-Whitney U-test assessed statistical significance. RESULTS: There were no significant differences in baseline characteristics between the untreated (n=46) and treated (n=39) populations. The mean Cobb angle variation did not significantly differ between the two groups (p=0.4). Optimal cut-off values for a better outcome were found to be having a Cobb angle <26° or an age <4.5 years. When using optimal cut-off, the treated group showed a lower mean Cobb variation compared with the untreated group (5.61 (SD 4.72) degrees/year vs 10.05 (SD 6.38) degrees/year; p=0.01). Cox-regression analysis indicated a protective treatment effect in reaching a 50° Cobb angle, significant in patients <4.5 years old (p=0.016). CONCLUSION: This study highlights that pharmacological treatment, if initiated early, may slow down the progression of scoliosis in type II SMA patients. Larger studies are warranted to further investigate the effectiveness of individual pharmacological treatment on scoliosis progression in this patient population.

Deformity correction using proximal hooks and distal screws (PHDSs) improves radiological metrics in adolescent idiopathic scoliosis.

PURPOSE: Surgical correction for AIS has evolved from all hooks to hybrids or all screw constructs. Limited literature exists reporting outcomes using PHDS for posterior spinal fusion (PSF). This is the largest series in evaluating results of PHDS technique. METHODS: A retrospective review of consecutive AIS patients undergoing PSF by a single surgeon between 2006 and 2015 was performed. All eligible patients met a minimum 2-year follow-up. Patient demographics and radiographical parameters (radiographic shoulder height (RSH), T1 tilt, clavicle angle) at baseline, 6-week and 2-year post-operation were recorded. The primary outcome was difference in RSH from baseline measurements evaluated using repeated measures one-way analysis of variance with Bonferroni correction. RESULTS: A total of 219 patients (mean age at surgery: 13.68 years; 82% female) were included. The mean follow-up was 41.2 months (range 24-108 months). The RSH was significantly improved from - 14.7 ± 10.38 mm to 8.0 ± 6.9 mm (P < 0.0001). Clavicle angle was improved from 2.13° to 1.31° (P < 0.0001). T1 tilt was improved from 5.6° to 2.2° (P < 0.0001). At last follow-up, 95.8% of patients were shoulder balanced. There was a significant improvement of Cobb angle with an average correction of the upper thoracic curve of 42% and main thoracic curve of 67%. CONCLUSION: The PHDS demonstrates the potential for additional shoulder balance improvement. Extension of fusion to structural proximal thoracic spine is the key to success for shoulder balance. It remains to be seen whether these improvements will translate into improved clinical outcomes in the longer term.

An Augmented Reality Device for Remote Supervision of Ultrasound Examinations in International Exercise Science Projects: Usability Study.

BACKGROUND: Support for long-distance research and clinical collaborations is in high demand and has increased owing to COVID-19-related restrictions on travel and social contact. New digital approaches are required for remote scientific exchange. OBJECTIVE: This study aims to analyze the options of using an augmented reality device for remote supervision of exercise science examinations. METHODS: A mobile ultrasound examination of the diameter and intima-media thickness of the femoral and carotid arteries was remotely supervised using a head-mounted augmented reality device. All participants were provided with a link to a YouTube video of the technique in advance. In part 1, 8 international experts from the fields of engineering and sports science were remotely connected to the study setting. Internet connection speed was noted, and a structured interview was conducted. In part 2, 2 remote supervisors evaluated 8 physicians performing an examination on a healthy human subject. The results were recorded, and an evaluation was conducted using a 25-item questionnaire. RESULTS: In part 1, the remote experts were connected over a mean distance of 1587 km to the examination site. Overall transmission quality was good (mean upload speed: 28.7 Mbps, mean download speed: 97.3 Mbps, mean ping: 21.6 milliseconds). In the interview, participants indicated that the main potential benefits would be to the fields of education, movement analysis, and supervision. Challenges regarding internet connection stability and previous training with the devices used were reported. In part 2, physicians' examinations showed good interrater correlation (interclass correlation coefficient: 0.84). Participants valued the experienced setting as highly positive. CONCLUSIONS: The study showed the good feasibility of the chosen design and a highly positive attitude of all participants toward this digital approach. Head-mounted augmented reality devices are generally recommended for collaborative research projects with physical examination-based research questions.

Rate of complications due to neuromuscular scoliosis spine surgery in a 30-years consecutive series.

PURPOSE: The aim of this study was to evaluate the rate of intraoperative and postoperative complications in a large series of patients affected by neuromuscular scoliosis. METHODS: It was a monocentric retrospective study. In this study have been considered complications those events that significantly affected the course of treatment, such as getting the hospital stay longer, or requiring a subsequent surgical procedure, or corrupting the final result of the treatment. RESULTS: Of the 358 patients affected by neuromuscular scoliosis treated from January 1985 to December 2010, 185 that met the inclusion criteria were included in the study. There were recorded 66 complications in 55/185 patients. Of that 66 complications, 54 complications occurred in 46/120 patients with Luque's instrumentation, while only 12 complications occurred in 9/65 patients with hybrid instrumentation and this difference was statistically significant (p < 0.05); 11/126 patients with pelvic fixation and 5/59 without pelvic fixation, as well as 45/156 patients treated by posterior approach alone and 10/29 patient that underwent combined anterior-posterior approach suffered complications but both this did not result in a statistical significant difference (p > 0.05). CONCLUSIONS: The surgical treatment in neuromuscular scoliosis is burdened by a large number of complications. An accurate knowledge of possible complications is mandatory to prepare strategies due to prevent adverse events. A difference in definitions could completely change results in good or bad as well as in our same series the adverse events amounted at almost 30% of cases, but complications that due to complete failure would amount at 9.19% of patients.

Single harvesting in the all-inside graft-link technique: is the graft length crucial for success? A biomechanical study.

BACKGROUND: The all-inside graft-link technique for anterior cruciate ligament reconstruction is performed with two cortical suspension devices with adjustable loops on both femur and tibia. This technique requires meticulous graft preparation. The aim of this study was to biomechanically test three different graft configurations resulting from differences in initial graft length. MATERIALS AND METHODS: Thirty bovine digital extensor tendons were arranged in three different ways: "half-quadrupled", "tripled" and "quadrupled". The final graft length was 65-75 mm. The specimens were fixed vertical to the loading axis of a tensile testing machine. After a static pre-conditioning of 50 N for 5 min, a load to failure test was performed and data regarding the ultimate failure load (UFL), the stiffness and mode of failure were recorded. RESULTS: The evaluation of UFL showed a significant differences between group means as determined by one-way analysis of variance (F = 21.92, p = 0.002). Post hoc comparisons showed a significantly better UFL of "tripled" (p = 0.007) and "quadrupled" preparations (p = 0.014) compared to the "half-quadrupled" configuration, with no significant differences between "tripled" and "quadrupled" grafts (p = 0.061). No significant differences were found when evaluating the stiffness between the groups. Failure occurred by tendon slippage across the suture in all specimens. CONCLUSION: The "quadrupled" tendon achieved the best UFL, with even the "tripled" configuration having sufficient biomechanical characteristics to withstand the loads experienced during early rehabilitation. For this reason, with a total semitendinosus length of less than 260 mm it could be better to "triple" instead of "half-quadruple" it to achieve better performance of the graft.

Efficacy of the assisted self-reduction technique for acute anterior shoulder dislocation.

INTRODUCTION: The "original" traction-free Kocher's method to perform the reduction of shoulder dislocation has been recently reviewed and some authors speculated that it can be self performed by patients under the guide of the physician. In this way, as an "assisted self-reduction" technique, it is also effective and simple to perform. The aim is to study the effectiveness of the assisted self-reduction technique, in comparison to the well known and largely used traction-countertraction method. MATERIALS AND METHODS: From a consecutive series of 237 uncomplicated anterior shoulder dislocations, a total of 61 were managed by the residents of our institution under the supervision of the senior authors using the assisted self-reduction method and 176 were managed by other orthopaedic consultants on duty in the Emergency Department using the traction-countertraction technique. Only the senior authors used the assisted self-reduction technique, whereas the other orthopaedic consultants used the traction-countertraction method. The need for intravenous sedation or general anaesthesia to perform the assisted self-reduction was considered a failure. Recorded variables were demographic data, previous dislocation, traumatic mechanism and medication use during shoulder reduction, time to perform the reduction. RESULTS: Ninety-eight percent of the acute dislocation treated with the assisted self-reduction technique and 81 % treated with the traction-countertraction method were reducible without recourse to intravenous sedation. CONCLUSIONS: The assisted self-reduction technique is simple, effective and gentle. Physicians on duty in the Emergency Departments should therefore be encouraged to use it.

Arthroscopic Physeal Sparing Anterior Cruciate Ligament Reconstruction and Lateral Extra-articular Tenodesis With Semitendinosus and Gracilis Tendons.

Anterior cruciate ligament (ACL) injuries among young patients have increased in recent years. The purpose of this study was to present a physeal-sparing intra- and extra-articular reconstruction using semitendinosus and gracilis tendons autograft. In recent years, the management of these injuries in the pediatric population has become increasingly surgical to restore knee function and reduce the risk of meniscal and chondral injury due to persistent knee instability. However, this is a population at high risk for ACL graft rupture, but it can be lowered by an addition of lateral extra-articular tenodesis (LET). This study shows the pearls and pitfalls of an arthroscopic physeal-sparing ACL reconstruction combined with a concomitant LET using hamstrings autograft.

The failure mode of two reabsorbable fixation systems: Swivelock with Fibertape versus Bio-Corkscrew with Fiberwire in bovine rotator cuff.

BACKGROUND: Despite technical advances in rotator cuff surgery, recurrent or persistent defects in the repaired tendon continue to occur. The improved strength of sutures and suture anchors has shown that the most common site of failure is the suture-tendon interface. The purpose of this study was to compare two different types of repair under both cyclic and load-to-failure conditions. The hypothesis is that the use of a fixation system with knotless anchor and taped suture results in better biomechanical performance, under both cyclic and load-to-failure conditions. METHODS: Thirty bovine shoulder specimens were randomly assigned to two group tests: the Swivelock 5-mm anchor with Fibertape (Group A) and the Bio-Corkscrew 5 mm with Fiberwire (Group B). We simulated the reconstruction of a rotator cuff tear with a single-row technique, performing a tenodesis with types A and B fixation. Each specimen underwent cyclic testing from 5 to 30 N for 30 cycles, followed by load-to-failure testing, in order to calculate the ultimate failure load (UFL). RESULTS: Load-to-failure tests revealed a significantly higher UFL in Group A than in Group B. Wire fixing failed at the anchor loop whereas tape fixing failed at the sutures, suture-tendon interface, and anchors. Cyclic testing revealed no significantly greater slippage between the two groups. Stiffness values were not statistically significantly different. In all cases, tendons remained intact until the end of the cyclic testing. CONCLUSIONS: The tape structure is biomechanically stronger than the wire structure.

Achieving Shoulder Balance Using Medial and Lateral Radiological Measures in Adolescent Idiopathic Scoliosis.

Background: Research has shown that postoperative shoulder imbalance is a common problem after spinal fusion in adolescent idiopathic scoliosis (AIS). The best radiographic predictor has not yet been determined and results are inconsistent. This study was to investigate whether using medial and lateral shoulder parameters can effectively achieve postoperative shoulder balance. Methods: A prospective database of AIS undergoing posterior spinal fusion were reviewed. Patient demographics and radiological parameters including radiographic shoulder height (RSH), clavicle angle, T1-tilt and first-rib angle at baseline, 6 weeks and last minimal follow up of 2 years were recorded. Correlations between radiological parameters were assessed using Pearson's correlation coefficients. Multivariable linear models identified predictors associated with increased RSH. Results: 219 patients (mean age:13.7 years; 81.7% female) were included. The mean follow-up time was 2.8 years (range:2.0-7.0). The mean RSH at baseline, 6 weeks and last follow up was improved significantly at 95.8%. Preoperative (r=0.8; p<0.001) and post-operative measurements of RSH at 6-week (r=0.9; p<0.001) and last follow up (r=0.9; p<0.001) correlated strongly with clavicle angle measured at respective time-points. In a multivariable linear model, we noted marginal increase in clavicle angle (+4.3°; p<0.001) to be associated with increased RSH. On the contrary, first rib angle and T1-tilt demonstrated moderate to weak correlation with RSH. Conclusion: Clavicle angle is strongly consistent with RSH. First rib angle and T1-tilt as demonstrate medial shoulder balance are moderate to weak correlation. Leveling T1 tilt and first rib angle do not guarantee the postoperative shoulder balance. Level of Evidence: IV.

The effectiveness of Kinesio Taping in improving pain and edema during early rehabilitation after Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized, Control Study.

BACKGROUND AND AIM: The Kinesio Taping (KT) is being increasingly applied in physical therapy and rehabilitation. The aim of this study was to evaluate the effect of KT on an early rehabilitation program, in combination with the standard protocol after ACL reconstruction (ACLR). METHODS: This study enrolled 52 male patients, aged 18 to 45 years, who underwent ACLR with doubled gracilis and semitendinosus tendon (DGST) autograft. The patients were randomized into 2 groups: Group A (the control group) which received a standard rehabilitation protocol, and Group B (the experimental group), which had the same rehabilitation protocol plus the KT application. Pain intensity, range of motion, edema, thigh circumference, Tegner-Lysholm Scale and KOOS scale were measured at the second and fourth week follow-ups. RESULTS: Patients in the experimental group showed significant results during the second week for both pain and edema reduction compared to the control group (p< 0.05). After 4 weeks of rehabilitation, pain intensity in the two groups was similar (n.s.), while edema reduction in the experimental group showed a significant result compared to the control group  (p< 0.05). Nevertheless, the other outcomes did not show significant differences. CONCLUSIONS: The application of KT after ACLR contributed to relieve pain and reduce edema in the early postoperative rehabilitation period. Other potential benefits of KT on muscle activation and strength should be investigated through a longer follow-up and a targeted test.

Long term follow-up of scoliosis progression in type II SMA patients.

The aim of this study is to retrospectively assess onset and progression of scoliosis in type II SMA patients not treated with the approved disease modifying treatments. Scoliosis was evaluated by measuring the scoliosis angle on X-ray obtained in the anteroposterior view in sitting position (Cobb's angle method). Eighty-four patients had at least one assessment of scoliosis angle (287 assessments). There was a positive correlation between age and scoliosis angles (p<0.001) with a progressive increase of scoliosis with age. When subdividing the population by HFMSE score (<10; 11-22;> 22), there was a progressive increase in scoliosis angles with decreasing HFMSE scores. The difference between HFMSE categories was significant (p<0.001). Fifty-four patients had at least two assessments at 6-month distance and were retained for the longitudinal analysis. Using a mixed model, age, functional status and scoliosis angle at baseline were predictive on scoliosis progression. The mean annual rate of increase of scoliosis angle was 5.63 (95%CI: 4.74-6.52). Our results confirm the progression of scoliosis in untreated type II SMA providing details of the progression in relation to different variables. With different therapeutical options being available in many countries, our findings will provide reference data for establishing possible differences in the trajectories of progression with treated type II individuals.

Magnetically Controlled Growing Rods for Early Scoliosis Treatment in Coffin-Siris Syndrome: Case Report and Literature Review.

Coffin-Siris Syndrome (CSS) is a rare, genetic syndrome characterized by multiple anomalies, including scoliosis. However, there are only a few reports about the management of scoliosis in these patients. We present the case of an 8-year-old female with CSS presenting with a progressive, rigid thoracolumbar kyphoscoliosis. She was successfully treated with a magnetically controlled growing rod, demonstrating improved ambulatory capacity and performance of activities of daily living. In pediatric patients with Coffin-Siris syndrome, magnetic expandable rods can be considered as an option for the management of progressive early-onset scoliosis. Level of Evidence: V.

Clinical and radiological outcomes of postoperative septic arthritis after anterior cruciate ligament reconstruction.

BACKGROUND: Septic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction is a rare complication. In the literature, several treatments have been proposed. The aim of the study was to report our results using ambulatory irrigation of the knee and parenteral and oral antibiotics. METHODS: From January 2001 to December 2008, a total of 12 patients were treated for postoperative septic arthritis of the knee after ACL reconstruction in our hospital. The average age at trauma was 24 years (range 16-43 years). The treatment protocol included irrigation of the knee (for 2 days) and parenteral antibiotics and oral antibiotics subsequently. Repetitive irrigation was performed if necessary. The average duration of follow-up for our series was 38 months (range 6-54 months). Follow-up included International Knee Documentation Committee (IKDC) forms, radiography, Tegner and Lysholm scores, and KT-1000 arthrometric evaluation. RESULTS: In all cases treatment of infection was successful. Neither graft nor hardware removal was needed in any of the cases. At final examination, the pivot shift was negative in 10 of 12 patients, and it was 1+ in the other 2 patients; the Lachman was negative in all cases. The mean postoperative Tegner score was 7.2, and the mean Lysholm score was 98.3. In all, 10 of the 12 patients were graded as group A and the other 2 as group B using the IKDC form. The mean postoperative manual maximum KT-1000 side-to-side difference was 2.3. No significant bone tunnel enlargement was found at radiographic evaluation. CONCLUSIONS: The described treatment regimen gives reliable results for this complication. There were no recurrences of septic arthritis or bone infection. No further surgeries were required, and the graft was retained during the treatment of septic arthritis.

Early-Onset Scoliosis Treated With Magnetically Controlled Growing Rods.

The recently developed magnetically controlled growing rod (MCGR) system has gained popularity because it limits additional surgical lengthening procedures and promises reduction of the complication rate previously reported for the traditional growing rods. A retrospective single-center study was performed. Demographic and complications data were recorded. A statistical analysis was conducted to quantify the effect of MCGR placement and of subsequent lengthening on the Cobb angle, T1-T12 kyphosis, and the distances from T1-T12 and T1-S1. Twenty-four patients met the inclusion criteria. Six had idiopathic scoliosis and 18 patients had nonidiopathic scoliosis (neuromuscular and syndromic scoliosis). Nine patients underwent primary MCGR placement, and 15 had the traditional growing rods removed and replaced with MCGRs. The mean age at surgery and at last follow-up was 6.3 years and 8.8 years, respectively. The mean follow-up was 29.2 months. The MCGR placement significantly reduced the Cobb angle and kyphosis by an average of 21.33° and 10.79°, respectively. The T1-T12 and the T1-S1 distances increased an average of 1.19 and 1.89 cm/year, respectively, during the follow-up period. The average percentage of achieved-to-intended distraction was 65% on the concave side and 68% on the convex side at last follow-up. There were 9 postoperative complications in 8 (33%) patients, 6 of whom had nonidiopathic scoliosis. The MCGR system is reliable and effective in the treatment of patients affected by early-onset scoliosis. [Orthopedics. 2020;43(6):e601-e608.].

Instrumented measurements of knee laxity: KT-1000 versus navigation.

The KT-1000 is widely accepted as a tool for the instrumented measurement of the antero-posterior (AP) tibial translation. The aim of this study is to compare the data obtained with the KT-1000 in ACL deficient knees with the data obtained using a navigation system during "in vivo" ACL reconstruction procedures and to validate the accuracy of the KT-1000. An ACL reconstruction was performed using computer aided surgical navigation (Orthopilot, B-Braun, Aesculap, Tuttlingen, Germany) in 30 patients. AP laxity measurements were obtained for all patients using KT-1000 arthrometer (in a conscious state and under general anaesthesia) and during surgery using the navigation system, always at 30 degrees of knee flexion. The mean AP translation was 14 +/- 4 and 15.6 +/- 3.8 mm using the KT-1000 in conscious and under general anaesthesia, respectively (P = 0.02) and 16.1 +/- 3.7 mm using navigation. Measurements obtained with the KT-1000 under general anaesthesia were no different from those obtained "in vivo" with the navigation system (P = 0.37). In conclusion this study validates the accuracy of the KT-1000 to exactly calculate AP translation of the tibia, in comparison with the more accurate measurements obtained using a navigation system.

Scoliosis and spinal muscular atrophy in the new world of medical therapy: providing lumbar access for intrathecal treatment in patients previously treated or undergoing spinal instrumentation and fusion.

This study describes a new procedure for a safer and easier access for the intrathecal injection of the recently approved nusinersen therapy in spinal muscular atrophy. This therapy changed the natural history of the disease, but, to date, scoliosis surgery was an excluding criteria for nusinersen therapy. The bone mass, due to the posterior spinal fusion of the scoliosis surgery, prevents the needle for the nusinersen administration from intervertebral access. This is a single-center, single-surgeon case series descriptive study. A laminotomy at the L3-L4 level was performed to provide safer access for the intrathecal injection. The procedure was carried out during the scoliosis surgery in patients who underwent posterior spinal fusion (PSF) after the nusinersen therapy was introduced, whereas for those who underwent PSF earlier, a second procedure was necessary to perform a laminotomy. A fat grafting was used to prevent bone overgrowth in the laminotomy. Markers were applied as radiographic references for the intrathecal injection. Five patients were enrolled, four females and one male. The mean age of the patients was 11 years. Three patients underwent PSF before the introduction of the nusinersen therapy. Two patients underwent PSF after the nusinersen therapy was available. All of them underwent a laminotomy with a fat grafting at the L3-L4 laminotomy level and received nusinersen therapy without complications. The procedure described is simple and effective in providing safe intrathecal access to make these patients eligible for such important therapy.

Acute Onset Atypical Severe Scoliosis: A Case Report.

Background: Although most cases of scoliosis are idiopathic, scoliosis may also be congenital or associated with other diseases. Herniated Nucleus Pulposus (HNP) has been reported as a potential cause of non-structural scoliosis. HNP is unusual in adolescents and the clinical features are typically different from those in adults. Case Presentation: An 18-year-old Caucasian male was referred to our ambulatory service for evaluation of scoliosis after orthopedic evaluation at another center. He had noticed left-sided low back pain in the previous 6 months, which had worsened over the last two months with the development of limp and left lower extremity (LLE) paresthesias. After an accurate clinical evaluation, the acute onset of the curvature with mild back pain and associated neurological findings were suggestive of an intraspinal lesion. The MRI examination showed an L4-L5 HNP compressing L4 nerve root and displacing the distal L5 nerve root. An L4-L5 laminectomy and discectomy were performed. His left leg pain was completely relieved the day after surgery. At 3 months follow-up complete resolution of scoliosis deformity and return to full activity was achieved. Conclusions: Every child who presents with atypical scoliosis should have a complete physical examination and appropriate imaging studies seeking an underlying cause.Level of Evidence: V.

Rare Post Traumatic Kyphoscoliosis of the Thoracolumbar Spine After Posterior Fusion for Adolescent Idiopathic Scoliosis: A Case Report and Review of the Literature.

Background: Vertebral fracture after posterior arthrodesis and instrumentation for idiopathic scoliosis is a rare occurrence with limited reported cases in the literature. Case Presentation: A 16-year-old female patient surgically treated for adolescent idiopathic scoliosis with T2-L1 posterior spinal fusion was in a low-energy fall resulting in fracture of L1 and new kyphosis and scoliosis of the thoracolumbar spine at the distal aspect of the fusion. The fracture was initially managed conservatively, however pain persisted and thus she was indicated for extension of the fusion and correction of the post-traumatic kyphosis. Conclusions: Fractures after posterior spinal fusion for idiopathic scoliosis are rare and evidence for the appropriate management remains limited in the literature.Level of Evidence: V.

A Child with a Rare Extraosseous Extension and Pathologic Fracture from a Vertebral Hemangioma: A Case Report.

CASE: We present a case of a pathologic vertebral fracture and encroachment into the spinal canal from a vertebral hemangioma in a 13-year-old boy. The original approach of embolization followed by an anterior-posterior resection and stabilization through a costotransversectomy had to be converted intraoperatively to a combined anterior and posterior approach secondary to excessive bleeding. CONCLUSION: Because of the hypervascularity and the extensive nature of aggressive vertebral hemangiomas, surgeons attempting procedures similar to the case described herein must be prepared to adapt to the circumstances when preoperative embolization is not totally effective. Surgical technique, proper anesthesia, and patient clotting capacity are important factors to consider.