As fast as an X-ray: real-time magnetic resonance imaging for diagnosis of idiopathic scoliosis in children and adolescents.

BACKGROUND: Idiopathic scoliosis is common in adolescence. Due to the rapid growth of the spine, it must be monitored closely with radiographs to ensure timely intervention when therapy is needed. As these radiographs continue into young adulthood, patients are repeatedly exposed to ionizing radiation. OBJECTIVE: This study aimed to investigate whether real-time magnetic resonance imaging (MRI) is equivalent to conventional radiography in juvenile idiopathic scoliosis for determining curvature, rotation and the Risser stage. Additionally, the time requirement should be quantified. MATERIALS AND METHODS: Children with idiopathic scoliosis who had postero-anterior whole-spine radiography for clinical indications were included in this prospective study. A real-time spine MRI was performed at 3 tesla in the supine position, capturing images in both the coronal and sagittal planes. The scoliosis was assessed using Cobb angle, rotation was evaluated based on Nash and Moe criteria, and the Risser stage was determined for each modality. The correlations between modalities and a correction factor for the Cobb angle between the standing and supine position were calculated. RESULTS: A total of 33 children (aged 5-17 years), who met the inclusion criteria, were recruited. The Cobb angle (R2 = 0.972; P < 0.01) was positively correlated with a correction factor of 1.07 between modalities. Additionally, the degree of rotation (R2 = 0.92; P < 0.01) and the Risser stage (R2 = 0.93; P < 0.01) demonstrated a strong correlation. CONCLUSION: Real-time MRI is equivalent to conventional radiography in determining baseline parameters. Furthermore, it is radiation-free and less time-consuming.

Cervical spine fractures in ankylosing spondylitis patients: an analysis of the presentation and clinical results of 110 surgically managed patients in two spine centers.

PURPOSE: In this work, a two-center study was performed to study the clinical presentation of cervical spine fractures in ankylosing spondylitis (AS) patients and assess the surgical management of these fractures. METHODS: A retrospective analysis of prospectively collected data in two level-1 spine surgery centers was performed. Both spine centers have a standard database for all admitted patients. Inclusion criteria were surgically treated AS with cervical spine fracture diagnosis (from C1 to Th3) and postoperative follow-up minimum of 12 months. RESULTS: One hundred ten patients (105 male/5 female) were included. The mean age was 62 ± 10 years. The mean time between trauma and surgery was 49 ± 42 days. There was a history of mild trauma in 72 patients (65.4%). The clinical presentation was a pain in all patients. Twenty-seven (24.6%) had a neurological deficit at admission. The most common fracture level was C6/7 in 63 patients (57.23%). The VAS was 7 ± 1, and NDI was 34 ± 8 in the preoperative assessment. The mean preoperative kyphosis angle was 48 ± 26° between C2 and C7. Positioning and preparing of the patients on the operation table took a mean of 57 ± 28 min. The surgical approach was dorsal in 59 patients (53.6%), combined in 45 patients (40.9%), and ventral in 6 patients (6,5%). The mean number of the fixed levels was 6 ± 2 levels. Intraoperative complications occurred in 9 patients (8.2%). Postoperative Cobb angle improved to a mean of 17 ± 9 degrees. Neurological improvement occurred in 20/27 patients. In 12 patients, the recovery was complete. The mean postoperative follow-up was 46 ± 18 months. VAS improved to 3 ± 1, and NDI improved to 14 ± 6 at the last postoperative visit. The improvement was clinically significant (p = 0.01 and 0.00, respectively). CONCLUSION: High suspicion of cervical spine fractures is necessary for patients with AS. CT and MRI images are necessary to rule out cervical spine fractures in AS patients, especially to detect occult fractures. Surgical treatment is safe, and the posterior approach with long-segment fusion is the approach of choice in this group of patients.

Biomechanical comparative study of midline cortical vs. traditional pedicle screw trajectory in osteoporotic bone.

INTRODUCTION: In lumbar spinal stabilization pedicle screws are used as standard. However, especially in osteoporosis, screw anchorage is a problem. Cortical bone trajectory (CBT) is an alternative technique designed to increase stability without the use of cement. In this regard, comparative studies showed biomechanical superiority of the MC (midline cortical bone trajectory) technique with longer cortical progression over the CBT technique. The aim of this biomechanical study was to comparatively investigate the MC technique against the not cemented pedicle screws (TT) in terms of their pullout forces and anchorage properties during sagittal cyclic loading according to the ASTM F1717 test. METHODS: Five cadavers (L1 to L5), whose mean age was 83.3 ± 9.9 years and mean T Score of -3.92 ± 0.38, were dissected and the vertebral bodies embedded in polyurethane casting resin. Then, one screw was randomly inserted into each vertebra using a template according to the MC technique and a second one was inserted by freehand technique with traditional trajectory (TT). The screws were quasi-static extracted from vertebrae L1 and L3, while for L2, L4 and L5 they were first tested dynamically according to ASTM standard F1717 (10,000 cycles at 1 Hz between 10 and 110 N) and then quasi-static extracted. In order to determine possible screw loosening, there movements were recorded during the dynamic tests using an optical measurement system. RESULTS: The pull-out tests show a higher pull-out strength for the MC technique of 555.4 ± 237.0 N compared to the TT technique 448.8 ± 303.2 N. During the dynamic tests (L2, L4, L5), 8 out of the 15 TT screws became loose before completing 10,000 cycles. In contrast, all 15 MC screws did not exceed the termination criterion and were thus able to complete the full test procedure. For the runners, the optical measurement showed greater relative movement of the TT variant compared to the MC variant. The pull-out tests also revealed that the MC variant had a higher pull-out strength, measuring at766.7 ± 385.4 N, while the TT variant measured 637.4 ± 435.6 N. CONCLUSION: The highest pullout forces were achieved by the MC technique. The main difference between the techniques was observed in the dynamic measurements, where the MC technique exhibited superior primary stability compared to the conventional technique in terms of primary stability. Overall, the MC technique in combination with template-guided insertion represents the best alternative for anchoring screws in osteoporotic bone without cement.

Approach for Non-Intrusive Detection of the Fit of Orthopaedic Devices Based on Vibrational Data.

The soft tissues of residual limb amputees are subject to large volume fluctuations over the course of a day. Volume fluctuations in residual limbs can lead to local pressure marks, causing discomfort, pain and rejection of prostheses. Existing methods for measuring interface stress encounter several limitations. A major problem is that the measurement instrumentation is applied in the sensitive interface between the prosthesis and residual limb. This paper presents the principle investigation of a non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputees based on experimentally obtained vibrational data. The proposed approach is based on changes in the dynamical behaviour detectable at the outer surface of prostheses; thus, the described interface is not affected. Based on the experimental investigations shown and the derived results, it can be concluded that structural dynamic measurements are a promising non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputee patients. The obtained resonance frequency changes of 2% are a good indicator of successful applicabilityas these changes can be detected without the need for complex measurement devices.

Does the use of epicutaneous vacuum-assisted closure after revision surgery on the spine reduce further wound revision surgery?

PURPOSE: This study aimed to investigate the effect of epicutaneous vacuum therapy on the rate of unplanned spinal wound revisions compared with conventional wound dressing. METHODS: This retrospective study included patients who underwent unplanned revision spine surgery after primary aseptic spine surgery who were treated at a level I spine centre between December 2011 and December 2019. Patients with revision surgery who required a further unplanned revision surgery during the inpatient stay were considered a treatment failure. The epicutaneous vacuum-assisted closure (Epi-VAC) therapy was the standard treatment method beginning in 2017 (the epi-VAC group). Before, conventional wound dressing was used (the control group (CG)). In addition, a one-to-one matched-pair comparison analysis was performed between both groups. RESULTS: Of 218 patients, 48 were in the epi-VAC group. The mean age was 65.1 years (epi-VAC 68.2 to CG 64.3 years (P = 0.085)), and the mean body mass index (BMI) was 28.2 kg/m2 (epi-VAC 29.4 to CG 27.9 kg/m2 (P = 0.16)). No significant differences in the treatment failure rate could be detected between the two groups (epi-VAC 25% to CG 22.4% (P = 0.7)). There was also no significant difference for the matched-pair analysis (epi-VAC 26.1% to CG 15.2% (P = 0.3)). An elevated CRP level (C-reactive protein) immediately before the first wound revision was a significant risk factor for further revision surgery (treatment failure: 135.2 ± 128.6; no treatment failure: 79.7 ± 86.1 mg/l (P < 0.05)). CONCLUSION: Concerning repeat unplanned wound revision after spinal revision surgery, we cannot demonstrate an advantage of the epicutaneous vacuum therapy over conventional wound dressing.

Functionalization of screw implants with superelastic structured Nitinol anchoring elements.

BACKGROUND: Demographic change is leading to an increase in the number of osteoporotic patients, so a rethink is required in implantology in order to be able to guarantee adequate anchoring stability in the bone. The functional modification of conventional standard screw implants using superelastic, structured Ti6Al4V anchoring elements promises great potential for increasing anchoring stability. METHODS: For this purpose, conventional screw implants were mechanically machined and extended so that structured-superelastic-positionable-Ti6Al4V anchoring elements could be used. The novel implants were investigated with three tests. The setup of the anchoring elements was investigated in CT studies in an artificial bone. In a subsequent simplified handling test, the handling of the functional samples was evaluated under surgical conditions. The anchorage stability compared to standard screw implants was investigated in a final pullout test according to ASTM F543-the international for the standard specification and test methods for metallic medical bone screws. RESULTS: The functionalization of conventional screw implants with structured superelastic Ti6Al4V anchoring elements is technically realizable. It was demonstrated that the anchoring elements can be set up in the artificial bone without any problems. The anchorage mechanism is easy to handle under operating conditions. The first simplified handling test showed that at the current point of the investigations, the anchoring elements have no negative influence on the surgical procedure (especially under the focus of screw implantation). Compared to conventional standard screws, more mechanical work is required to remove the functional patterns completely from the bone. CONCLUSION: In summary, it was shown that conventional standard screw implants can be functionalized with Ti6Al4V-structured NiTi anchoring elements and the new type of screws are suitable for orthopedic and neurosurgical use. A first biomechanical test showed that the anchoring stability could be increased by the anchoring elements.

In vivo detection of the lumbar intraforaminal ligaments by MRI.

PURPOSE: Intraforaminal ligaments (IFL) are of great interest to anatomists and clinicians to fully understand the detailed anatomy of the neuroforamina and to diagnose unclear radicular symptoms. Studies published until now have described radiological imaging of the IFLs using magnetic resonance imaging (MRI) on donor bodies. In the present study, we investigated the detectability of lumbar IFLs in vivo in adults using the high spatial resolution of the constructive interference in steady state (CISS) sequence. METHODS: A total of 14 patients were studied using a 1.5 T MRI scanner. The lumbar spine was imaged using the parasagittal CISS sequence, and the detectability of the IFLs was assessed for each lumbar level. All image datasets were analyzed by a radiologist, an orthopedic surgeon, and an anatomist. Interrater reliability was expressed as Fleiss' Kappa. Using a single data set, a three-dimensional (3D) model was created to map the location of the IFLs within the intervertebral foramen (IF) and the immediate surrounding vessels. RESULTS: Overall, the radiologist was able to detect IFLs in 60% of all imaged IFs, the orthopedic surgeon in 62%, and the anatomist in 66%. Fleiss' Kappa for the various segments varies from 0.71 for L4/5 up to 0.90 for L3/4. CONCLUSION: Lumbar IFLs were successfully detected in vivo in every patient. The detection frequency varied from 42-86% per IF. We demonstrated reproducible imaging of the IFLs on MRI, with good interrater reliability. The present study was a launching point for further clinical studies investigating the potential impact of altered IFLs on radicular pain.

Sacroiliac innervation.

PURPOSE: To investigate the innervation pattern of the sacroiliac region, especially with regard to the sacroiliac joint (SIJ). Dorsal SIJ innervation was analyzed and described. Our main hypothesis was that nerves reach the SIJ dorsally, passing ligamental compartments, as this would explain dorsal SIJ pain. METHODS: To examine sacroiliac innervation, we followed the nerves in over 50 specimens over several years. Plastinated slices were evaluated, nerves in the region were stained histologically, and the data were summarized as 3D models. RESULTS: The Rami communicans and posterior branches of the spinal nerves and their branches that form a dorsal sacral plexus and communicating branches, together with corresponding vessels, were observed to form neurovascular bundles embedded by tiny fatty connectives in gaps and tunnels. Branches of L5-S1 pass the inner sacroiliac ligaments (the interosseous sacroiliac ligament and axial interosseous ligament). The outer sacroiliac ligaments (posterior sacroiliac ligaments, long posterior sacroiliac ligament, sacrotuberal ligament, thoracolumbar fascia) are passed by the S1-S4 branches. However, although the paths of these nerves are in the direction of the SIJ, they do not reach it. It is possible that impingement of the neurovascular bundles may result in pain. Moreover, the gaps and tunnels connect to the open dorsal SIJ. CONCLUSION: Our findings suggest that Bogduk's term "sacroiliac pain" correlates to "sacroiliac innervation", which consists of "inner-" and "outer sacroiliac ligament innervation", and to ventral "SIJ pain". The watery gaps and tunnels observed could play a significant role in innervation and thus in the origins of SIJ pain. LEVEL OF EVIDENCE: Individual cross-sectional studies with consistently applied reference standard and blinding.

Does the anatomical region predict blood loss or neurological deficits in embolized renal cancer spine metastases? A single-center experience with 31 patients.

BACKGROUND: No comparison of a single hypervascular tumor entity in terms of major complications in different spinal regions has been performed. We aimed to evaluate post-embolic and post-operative outcomes in anatomic regions with renal cell carcinoma (RCC) metastases to the spine. METHODS: We retrospectively evaluated data from patients with confirmed, embolized, and surgically treated RCC spine metastases at a single-spine center between 2010 and 2020. Patients were divided into thoracic (TSM) and lumbar (LSM) spine metastasis groups. RESULTS: Seventeen patients had TSM and 14 had LSM. In all cases, embolization was performed preoperatively. The ΔHb value did not differ between the two groups pre- and postoperatively (p=0.3934). There was no significant difference in intraoperative blood loss between both groups either within 1 day or 2 days after embolization. Neurological deficits occurred in eight patients after embolization or surgery, with no significant difference between TSM (n=5) and LSM (n=3). CONCLUSIONS: Embolization is the standard procedure for the preoperative treatment of hypervascular spinal metastases, possible up to 48 h before surgery, without the risk of higher intraoperative blood loss. Regardless of intraoperative complications, major complications can occur up to several hours after embolization. We recommend surgery the day after embolization to reliably detect neurologic complications from this procedure.

Complications of injections in conservative treatment of degenerative spine disease: a prospective unicentric study.

BACKGROUND: Spinal injection has been an accepted part of conservative therapy for degenerative diseases. The drugs used can cause side effects and severe complications. The aim of this study was to determine the occurrence of general side effects (GSE) and complications when performing consecutive different types of spinal injections and to evaluate pain reduction. METHODS: Prospective data evaluation of patients with degenerative spine disease at hospital admission, discharge, and six and 12 weeks after discharge. All patients received a specific injection protocol depending on their symptoms and radiological findings. The injections performed were dorsal sacroiliac joint injections, perineural injections, epidural interlaminar and epidural periradicular injections, and facet joint injections. Potential complications were categorized and recorded as GSE and complications. In addition, the Numerical Analog Scale (NAS) for pain, the Oswestry Disability Index (ODI) were evaluated. RESULTS: Forty-eight patients were enrolled. There were 282 spinal injections performed. A total of 131 common treatment-related events were recorded. Depending on the type of injection, transient pain at the injection site (32.4-73.5%), radiating pain (9.4-34.7%), and nerve root irritation (2-18.4%) were the most common. One complication with postpuncture syndrome occurred with epidural-interlaminar injection. No persistent neurologic deficits occurred. The highest rate of GSE was observed with periradicular injections (relative frequency (RF) = 0.8), followed by epidural-interlaminar injections (RF = 0.65), least frequently with FJ injections (RF = 0.32). From the time of admission to discharge, NAS scores were significantly decreased and ODI score significantly improved at discharge (p < 0.001), but relapse occurred at the 12-week follow-up. CONCLUSIONS: Various consecutive spinal injections for conservative treatment of degenerative spine diseases are safe and lead to a decrease in pain and improvement in quality of life. GSE are common, but not persistent. Although complications are rare, they can have serious consequences for the patient.

Does time-to-surgery affect mortality in patients with acute osteoporotic vertebral compression fractures?

INTRODUCTION: Osteoporotic vertebral compression fractures (VCFs) are common. An increase in mortality associated with osteoporotic VCFs has been well documented. The purpose of this study was to assess the impact of time to surgery on 1-year survival in patients with osteoporotic vertebral compression fractures. METHODS: In a retrospective cohort study with prospective mortality follow-up, consecutive patients aged ≥ 60 years who had operative treatment of a low-energy fracture of a thoracolumbar vertebra and had undergone surgical stabilization between January 2015 and December 2018 were identified from our institutional database. By chart review, additional information on hospitalization time, comorbidities (expressed as ASA - American Society of Anesthesiologists Scale), complications and revision surgery was obtained. Time-to-surgery was defined as the time between admission and surgery. Mortality data was assessed by contacting the patients by phone, mail or the national social insurance database. RESULTS: Two hundred sixty patients (mean age 78 years, SD 7 years, range, 60 to 93; 172 female) were available for final analysis. Mean follow-up was 40 months (range, 12 to 68 months). Fifty-nine patients (22.7%) had died at final follow-up and 27/260 patients (10.4%) had died within 1 year after the surgery. Time-to-surgery was not different for patients who died within 1 year after the surgery and those who survived (p = .501). In-hospital complications were seen in 40/260 (15.4%) patients. Time-to-surgery showed a strong correlation with hospitalization time (Pearson's r = .614, p < .001), but only a very weak correlation with the time spent in hospital after the surgery (Pearson's r = .146, p = .018). CONCLUSIONS: In contrast to patients with proximal femur factures, time-to-surgery had no significant effect on one-year mortality in geriatric patients with osteoporotic vertebral compression fractures. Treatment decisions for these fractures in the elderly should be individualized.

Clinical suspicion of spondylodiscitis with equivocal MRI findings: does diffusion-weighted imaging prove helpful here?

BACKGROUND: Despite the high sensitivity of magnetic resonance imaging (MRI), early detection of spondylodiscitis (SpD) remains challenging due to its low specificity. PURPOSE: To assess the diagnostic value of diffusion-weighted imaging (DWI) in suspected cases of SpD with ambiguous early MRI findings in the differentiation of degenerative disorders (DD). MATERIAL AND METHODS: In this prospective study, 52 patients suspected of having SpD underwent a whole-spine 3-T MRI scan comprising sagittal DWI. Of 58 conspicuous, T2-weighted, signal increased discs, 39 were successfully evaluated using DWI. Apparent diffusion coefficient (ADC) values and ADC maps were blindly analyzed using the region of interest of the conspicuous disc and a normal adjacent reference disc. Intraindividual ratios (conspicuous disc: reference disc) were calculated. RESULTS: All conspicuous discs showed increased absolute ADC values, which did not differ significantly between SpD (n = 22) and DD (n = 17). However, ADC ratio was significantly higher in SpD vs. DD (P < 0.05). In receiver operating characteristic curve analysis, an ADC ratio threshold of 1.6 resulted in 45% sensitivity and 88% specificity (area under the curve = 0.69) for SpD diagnosis. CONCLUSION: The absolute ADC value does not provide a reliable diagnosis of SpD. Increased diffusivity can be an indication of infection but should always be discussed in the context of existing disc degeneration.

Spondylodiscitis due to transmitted mycotic aortic aneurysm or infected grafts after endovascular aortic aneurysm repair (EVAR): A retrospective single-centre experience with short-term outcomes.

PURPOSE: To report the challenging therapeutic approach and the clinical outcome of patients with pyogenic spondylodiscitis transmitted due to infected retroperitoneal regions of primary infected mycotic aortic aneurysms (MAAs) or secondary infected aortic stent grafts after endovascular aneurysm repair (EVAR). METHODS: Between 2012 and 2019, all patients suffering from spondylodiscitis based on a transmitted infection after the EVAR procedure were retrospectively identified. Patient data were analysed regarding the time between primary and secondary EVAR infection and spondylodiscitis detection, potential source of infection, pathogens, antibiotic treatment, complications, recovery from infection, mortality, numeric rating scale (NRS), COBB angle and cage subsidence. RESULTS: Fifteen patients with spondylodiscitis transmitted from primary or secondary infected aortic aneurysms after EVAR were included. The median follow-up time was 8 months (range 1-47). Surgery for spondylodiscitis was performed in 12 patients. In 9 patients, the infected graft was treated conservatively. MAAs were treated in 4 patients first with percutaneous aortic stent graft implantation followed by posterior surgery of the infected spinal region in a two-step procedure. Infection recovery was recorded in 11 patients during follow-up. The overall mortality rate was 27% (n = 4). The mean pain intensity improved from an NRS score of 8.4 (3.2-8.3) to 3.1 (1.3-6.7) at the last follow-up. CONCLUSION: EVAR was used predominantly to treat primary infected MAAs. Secondary infected grafts were treated conservatively. Independent of vascular therapy, surgery of the spine led to recovery in most cases. Thus, surgery should be considered for the treatment of EVAR- and MAA-related spondylodiscitis.

Total spine magnetic resonance imaging for detection of multifocal infection in pyogenic spondylodiscitis: a retrospective observational study.

BACKGROUND: Due to the unspecific symptoms of spondylodiscitis (SpD), an early radiological examination is necessary. However, controversially discussed is the need for magnetic resonance imaging of the entire spine to exclude multisegmental infections and to determine the required surgical interventions. The aims of this study were to assess the incidence of multilevel non-contiguous pyogenic SpD and compare comorbidities, pain symptoms, and subsequent surgical strategies between unifocal (uSpD) and multifocal (mSpD) SpD. METHODS: We retrospectively evaluated the data of patients with confirmed, surgically treated, pyogenic SpD who had received a total spine MRI in a single spine center between 2016 and 2018. MRI findings were classified according to Pola-classification and demographics, duration of clinical symptoms (pain and neurology) and Charlson Comorbidity-Index (CCI) results were compared between uSpD und mSpD groups. Surgical therapy was evaluated in patients with mSpD. RESULTS: uSpD was detected by MRI in 69 of 79 patients (87%). Of these, mSpD was detected in 10 patients (13%) with 21 infected segments (cervical and/ or thoracic and/ or lumbar region). Age and CCI were similar between uSpD and mSpD and 24 of all SpD regions were clinically unapparent. All patients with uSpD were treated operatively. In seven patients with mSpD, all infected levels of the spine were treated surgically in a one-stage procedure; one patient had a two-stage procedure and one patient had surgery at the lumbar spine, and an additional infected segment of the upper thoracic spine was treated conservatively. One patient died before a planned two-stage procedure was performed. CONCLUSIONS: Due to mSpD being found in approximately 13% of SpD cases, and considering the risk of overlooking an mSpD case, MRI imaging of the total spine is recommended. The detection of multiple infection levels can have an impact on the therapeutic strategy chosen.

Risk factors for wound-related complications after surgical stabilization of spinal metastases with a special focus on the effect of postoperative radiation therapy.

BACKGROUND: Advancements in the field of oncological therapies during the last decades have led to a significantly prolonged survival of cancer patients. This has led to an increase in the incidence of spinal metastases. The purpose of this study was to assess risk factors for wound-related complications after surgical stabilization of spinal metastases with a special focus on the effect of postoperative RT and its timing. METHODS: Patients who had been treated for metastatic spine disease by surgical stabilization followed by radiotherapy between 01/2012 and 03/2019 were included and a retrospective chart review was performed. RESULTS: Of 604 patients who underwent stabilizing surgery for spinal metastases, 237 patients (mean age 66 years, SD 11) with a mean follow-up of 11 months (SD 7) were eligible for further analysis. Forty-one patients (17.3%) had wound-related complications, 32 of them before and 9 after beginning of the RT. Revision surgery was necessary in 26 patients (11.0%). Body weight (p = 0.021), obesity (p = 0.018), ASA > 2 (p = 0.001), and start of radiation therapy within 21 days after surgery (p = 0.047) were associated with an increased risk for wound complications. Patients with chemotherapy within 3 weeks of surgery (12%) were more likely to have a wound-related surgical revision (p = 0.031). CONCLUSION: Body weight, obesity and ASA > 2 were associated with an increased risk for wound complications. Patients with chemotherapy within 3 weeks of the surgery were more likely to have a wound-related revision surgery. Patients who had begun radiation therapy within 21 days after surgery were more likely to have a wound complication compared to patients who waited longer.

Proof of Concept for the Detection of Local Pressure Marks in Prosthesis Sockets Using Structural Dynamics Measurement.

The wear comfort of a prosthesis is of great importance for amputee patients. The wear comfort can be affected by changes in the interface between the residual limb and prosthesis socket, which can be caused by time-dependent volume fluctuations of the tissue, leading to unwanted local pressure marks. The basis to ensure time-independent wear comfort of a prosthesis is to identify these changes. Common techniques for identifying these variations have a negative impact on the sensitive interface between the residual limb and prosthesis. The following paper contains a proof of concept for the detection of local pressure marks without affecting the described interface using structural dynamics measurements, exemplarily shown at a prosthetic socket for transfemoral amputees in a test bench scenario. The dynamical behaviour of the investigated system is analysed in the form of frequency response functions acquired for different pressure locations and preloads using an impact hammer for excitation and a triaxial acceleration sensor. The frequency response functions show major changes for the various boundary conditions with respect to their frequency-dependent compositions. The results demonstrate how the utilised method enables the identification of changes in local pressure marks regarding the variation of position and magnitude.

[Etiology, epidemiology, prognosis and biomechanical principles of neuromuscular scoliosis]. / Ätiologie, Epidemiologie, Prognose und biomechanische Besonderheiten neuromuskulärer Skoliosen.

Deformity due to neuromuscular disease is often progressive and associated with reduced vital capacity. In general, all treatment should be performed in specialized centers, since invasive measures are associated with an increased morbidity compared to adolescent scoliosis. Derived from the etiology and the resulting biomechanical basis (characteristics), important aspects and considerations arise for all healthcare institutions from the examination interval to the duration of conservative therapy and initiation of surgical therapy. Proper monitoring and assessment are key components to identify curve progression and to achieve preservation or improvement of basic functions.

Magnetic resonance tomography for the early detection of occult fractures of the spinal column in patients with ankylosing spondylitis.

PURPOSE: The purpose of this study was to determine the extent to which magnetic resonance imaging (MRI) performed in patients with ankylosing spondylitis (AS) after low- and no-energy trauma leads to an improved diagnosis and, as a result, to a change in the therapeutic strategy. METHODS: All patients with AS, who underwent surgery after minor traumas (low-energy traumas, LETs) and patients without trauma history (NET: no-energy trauma), were retrospectively analysed. The diagnostic and planned surgical procedure was examined initially and again after total spine MRI in patients with persistent and/or new complaints. RESULTS: One hundred and thirty-six patients with AS after trauma were surgically treated. A total of 92 patients with LETs and 12 patients with NETs were included. After initial diagnostics (CT and X-ray) were performed in 15.4% of the patients with LET or NET (n = 16), we found occult fractures on MRI scans. In ten of these patients (6 LET, 4 NET) in which a previous decision was made to follow conservative therapy, no fracture indication was found on CT or X-ray. Two fracture heights were observed in six patients who experienced LET. However, on X-ray and CT, the fractures were only visible at one height. All fractures were treated surgically with stabilization and decompression if indicated. CONCLUSION: Considering the high percentage of our patient population with occult fractures, we recommend supplementing the basic diagnostic procedures with an MRI of the entire spinal column in patients with painful spinal column findings after minor trauma and for those with persistent pain without trauma. These slides can be retrieved under Electronic Supplementary Material.

The reliability of a restraint sensor system for the computer-supported detection of spinal stabilizing muscle deficiencies.

BACKGROUND: The presence of muscular deficiency seems to be a major cause of back pain that requires counteractions. Considering that the autochthonous back muscles, responsible for straightening and stabilizing the spine, cannot be activated voluntarily, they can be strengthened only through specific training. The computer-supported test and training system (CTT) Centaur (BfMC GmbH, Leipzig, SN, Germany) seems well suited for this purpose. To show its potential as a reliable diagnostic and training tool, this study aimed to evaluate the test-retest reliability of this 3D spatial rotation device. METHODS: A prospective pilot study was conducted in 20 healthy volunteers of both sexes. For test-retest reliability analysis, three measurements were performed with a two-day interval between each measurement. Each measurement consisted of a one-minute endurance test performed in eight different positions (transverse plane). During the test, the subject was tilted by 90° in the sagittal plane from a neutral, upright position. Meanwhile, the subject's level of upper body stabilization along the body axis was assessed. All trunk movements (momentum values) were quantified by a multicomponent force sensor and standardized relative to the subject's upper body mass. The range of motion was assessed by 95% confidence ellipse analysis. Here, all position-specific confidence ellipses for each measurement were merged to a summarized quantity. Finally, ICC analysis using a single-rating, absolute agreement, two-way mixed-effects model and a Bland-Altman plot was performed to determine the reliability. RESULTS: Considering all measurements (t1, t2, t3), the ICC for reliability evaluation was 0.805, and the corresponding 95% confidence interval (CI) was [0.643, 0.910]. Moreover, the Bland-Altman plots for all three pairs of time points did not show significant differences. CONCLUSION: This study concludes that the CTT Centaur shows good test-retest reliability, indicating it can be used in clinical practice in the future.

Percutaneous versus open posterior stabilization in AOSpine type A3 thoracolumbar fractures.

BACKGROUND: The purpose of this retrospective cohort study was to compare treatment strategies of two level-one trauma centers regarding clinical and radiological outcomes focusing on non-osteoporotic AOSpine type A3 fractures of the thoracolumbar spine at levels T11 to L2. METHODS: Eighty-seven patients between 18 and 65 years of age that were treated operatively in either of two trauma centers were included. One treatment strategy includes open posterior stabilization whereas the other uses percutaneous posterior stabilization. Both included additional anterior fusion if necessary. Demographic data, McCormack classification, duration of surgery, hospital stay and further parameters were assessed. Owestry Disability Index (ODI), Visual Analog Scale (VAS) and SF-36 were measured for functional outcome. Bisegmental kyphosis angle, reduction loss and sagittal alignment parameters were assessed for radiological outcome. Follow up was at least 24 months. RESULTS: There was no significant difference regarding our primary functional outcome parameter (ODI) between both groups. Regarding radiological outcome kyphosis angle at time of follow up did not show a significant difference. Reduction loss at time of follow up was moderate in both groups with a significantly lower rate in the percutaneously stabilized group. Surgery time was significantly shorter for posterior stabilization and anterior fusion in the percutaneous group. Time of hospital stay was equal for posterior stabilization but shorter for anterior fusion in the open stabilized group. CONCLUSION: Both treatment strategies are safe and effective showing only minor loss of reduction. Clinical relevant differences in functional and radiographic outcome between the two surgical groups could not be demonstrated. TRIAL REGISTRATION: It was conducted according to ICMJE guidelines and has been retrospectively registered with the German Clinical Trials Registry (identification number: DRKS00015693, 07.11.2018).