An evaluation of a novel method for the MRI-based assessment of Caton-Deschamps index in the Knee.

INTRODUCTION: The radiographical assessment of patella height has historically been performed using X-Ray. The aim of this study was to evaluate a new method for the assessment of patella height using MRI and to assess the correlation with the X-Ray based assessment. MATERIALS AND METHODS: 159 patients who had both lateral radiographs and MRI images were included. Parameters measured included traditional radiographical CDI, MRI-based CDI, and TT-TG distance. On the basis of the TT-TG, the patients were divided into 2 groups. Two different methods were used to assess CDI using MRI: using a single slice image, and an alternative technique using two different cross-sectional images. The correlation of the two measurement methods was assessed using Pearson's correlation coefficient. The intraclass correlation coefficient (ICC) was determined from the measurements of the two investigators. RESULTS: The average TT-TG distance was 11.6 mm (± 4.6). In patients with a TT-TG < 15 mm, both measurement methods showed comparable correlation with measurements on X-Ray. In patients with a TT-TG of > 15 the the new cross-sectional imaging method showed higher correlation with traditional X-Ray assessment compared to CDI assessment using the traditional single slice method (r = 0.594, p < 0.001 vs. r = 0.302, p = 0.055). CONCLUSIONS: The assessment of CDI on MRI using a cross-sectional imaging method has a better correlation with traditional X-Ray assessment of CDI than single-slice assessment. This is particularly true in patients with elevated TT-TG and as such should be preferentially used in the assessment of Patellar height in this cohort.

A replicating LCMV-based vaccine for the treatment of solid tumors.

Harnessing the immune system to eradicate tumors requires identification and targeting of tumor antigens, including tumor-specific neoantigens and tumor-associated self-antigens. Tumor-associated antigens are subject to existing immune tolerance, which must be overcome by immunotherapies. Despite many novel immunotherapies reaching clinical trials, inducing self-antigen-specific immune responses remains challenging. Here, we systematically investigate viral-vector-based cancer vaccines encoding a tumor-associated self-antigen (TRP2) for the treatment of established melanomas in preclinical mouse models, alone or in combination with adoptive T cell therapy. We reveal that, unlike foreign antigens, tumor-associated antigens require replication of lymphocytic choriomeningitis virus (LCMV)-based vectors to break tolerance and induce effective antigen-specific CD8+ T cell responses. Immunization with a replicating LCMV vector leads to complete tumor rejection when combined with adoptive TRP2-specific T cell transfer. Importantly, immunization with replicating vectors leads to extended antigen persistence in secondary lymphoid organs, resulting in efficient T cell priming, which renders previously "cold" tumors open to immune infiltration and reprograms the tumor microenvironment to "hot." Our findings have important implications for the design of next-generation immunotherapies targeting solid cancers utilizing viral vectors and adoptive cell transfer.

Scientific Productivity of University Orthopaedics and Trauma Surgery in Germany, Austria, and Switzerland. / Wissenschaftliche Produktivität der universitären Orthopädie und Unfallchirurgie in der DACH-Region.

BACKGROUND: Despite major achievements, such as the development of hip prostheses, scientific productivity in orthopaedics and trauma surgery has hardly been investigated. Our study's aim therefore was to analyse the correlation between the leading physicians' h-index and their academic rang, in order to determine whether this objective measure of scientific accomplishments correlates with clinical position. METHODS: All physicians in leading positions at university hospitals' orthopaedics or trauma surgery departments in Germany, Austria, and Switzerland were included. Year of habilitation, number of publications and citations as well as h-index were collected from September to November 2020. RESULTS: A total of 844 leading physicians at 46 university hospitals were included. Professors had the highest number of total publications (117.4 ± 124.8, p < 0.001) and highest h-index (20.1 ± 10.1, p < 0.001). We found significant differences in the total number of publications (p = 0.001), publications in the last three years (p < 0.001), and h-index (p < 0.001) between the three investigated nations, with all parameters being highest in Switzerland. CONCLUSION: Our study shows that increasing scientific productivity is correlated with academic success. The country-specific differences indicate significant differences in the value of scientific activity in daily clinical routine.

Optimising both disease control and glucocorticoid dosing is essential for bone protection in patients with rheumatic disease.

OBJECTIVES: Inflammatory rheumatic and musculoskeletal diseases (iRMDs) are associated with increased systemic bone loss that is mediated by chronic inflammation, treatment with glucocorticoids (GCs) and other factors. Our objective was to analyse the impact of variables that influence osteoporosis (OP) in patients with iRMD treated with GC. METHODS: Rh-GIOP (acronyme) is a prospective observational cohort study investigating bone health in consecutive patients with iRMD and current or prior GC treatment. We present an analysis of the patients' baseline data here. Bone mineral density (BMD) measured by dual X-ray absorptiometry was the primary outcome. Multivariable linear regression models were performed to identify variables associated with BMD. RESULTS: Data from 1066 patients with iRMD were analysed. GC doses of <5 mg prednisone equivalent per day, cumulative dose and duration of GC therapy were not associated with negative effects on BMD. Dosages of ≥5 mg/day lost their negative association with BMD after adjustment for confounders. When subanalysing patients with exactly 5 mg/day, no negative effect was seen. For patients with rheumatoid arthritis (RA), GC doses of >7.5 mg/day showed a negative association with BMD overall, but this effect seemed to be specific only to patients with moderate or high disease activity (Disease Activity Score 28-C reactive protein >3.2). CONCLUSIONS: GCs of ≤5 mg/day did not seem to be associated with a reduction of BMD in patients with iRMD and current or prior exposure to GC. This is most likely due to the dampening of inflammation by GC, which exerts a mitigating effect on the risk of OP. In RA, current GC doses of >7.5 mg/day were negatively associated with BMD, but only in patients with moderate to high disease activity. TRIAL REGISTRATION NUMBER: NCT02719314.

Does Total Hip Arthroplasty Affect Spinopelvic and Spinal Alignment?: A Prospective Observational Investigation.

STUDY DESIGN: A prospective observational study, level of evidence 3. OBJECTIVES: The study with patients undergoing unilateral total hip arthroplasty (THA) aimed to evaluate the following hypotheses: (1) the spinal sagittal and coronal alignment alters due to THA, (2) the spinopelvic parameter changes after THA, (3) the spinopelvic alignment differs between sagittal balanced and imbalanced patients. SUMMARY OF BACKGROUND DATA: Surgical correction of spinal sagittal misalignment affects the spinopelvic alignment and pelvic tilt. It is not yet known to what extent THA affects spinopelvic, spinal sagittal, and coronal alignment. MATERIALS AND METHODS: A total of 153 patients undergoing THA were assessed with biplanar stereoradiography in standing position preoperatively and postoperatively. Two independent investigators examined C7-sagittal vertical axis (C7-SVA), pelvic incidence-lumbar lordosis (PI-LL) mismatch, lumbar lordosis (LL), C7-central sacral vertical line, pelvic oblique angle lumbosacral, intra-pelvic oblique angle, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA). An analysis of the sagittal misaligned subgroups of C7-SVA and PI-LL on the influence of the spinopelvic alignment was performed. RESULTS: A significant difference in spinopelvic parameters was detected in the preoperative to postoperative comparison (SS, PT, APPT, and PFA; P <0.000) ( d =-0.394; d =0.609; d =-0.481; d =0.431). The coronal alignment and pelvic obliquity revealed no significant differences. The misaligned groups (C7-SVA; PI-LL) demonstrated significant increases in PI and PT and decreased in LL compared with the groups with normal sagittal alignment. Preoperatively, 66/153 (C7-SVA) and 46/153 (PI-LL) of the THA patients presented sagittal misalignment, respectively. CONCLUSIONS: The results suggest an effect of THA on sagittal spinal and spinopelvic alignment, with a significant reduction of PT postoperatively and no effect on coronal alignment. Particularly striking are the significant differences in the misaligned groups, which may be classified as risk population and potentially can contribute biomechanically to a higher risk of posterior impingement and anterior THA dislocation. The substantial proportion of sagittal misaligned patients in the THA collective illustrates the crucial need for interdisciplinary collaboration.

Metabolic reprogramming of synovial fibroblasts in osteoarthritis by inhibition of pathologically overexpressed pyruvate dehydrogenase kinases.

Osteoarthritis (OA) is the most common degenerative joint disease and a major cause of age-related disability worldwide, mainly due to pain, the disease's main symptom. Although OA was initially classified as a non-inflammatory joint disease, recent attention has been drawn to the importance of synovitis and fibroblast-like synoviocytes (FLS) in the pathogenesis of OA. FLS can be divided into two major populations: thymus cell antigen 1 (THY1)- FLS are currently classified as quiescent cells and assumed to destroy bone and cartilage, whereas THY1+ FLS are invasively proliferative cells that drive synovitis. Both THY1- and THY1+ FLS share many characteristics with fibroblast-like progenitors - mesenchymal stromal cells (MSC). However, it remains unclear whether synovitis-induced metabolic changes exist in FLS from OA patients and whether metabolic differences may provide a mechanistic basis for the identification of approaches to precisely convert the pathologically proliferative synovitis-driven FLS phenotype into a healthy one. To identify novel pathological mechanisms of the perpetuation and manifestation of OA, we analyzed metabolic, proteomic, and functional characteristics of THY1+ FLS from patients with OA. Proteome data and pathway analysis revealed that an elevated expression of pyruvate dehydrogenase kinase (PDK) 3 was characteristic of proliferative THY1+ FLS from patients with OA. These FLS also had the highest podoplanin (PDPN) expression and localized to the sublining but also the lining layer in OA synovium in contrast to the synovium of ligament trauma patients. Inhibition of PDKs reprogrammed metabolism from glycolysis towards oxidative phosphorylation and reduced FLS proliferation and inflammatory cytokine secretion. This study provides new mechanistic insights into the importance of FLS metabolism in the pathogenesis of OA. Given the selective overexpression of PDK3 in OA synovium and its restricted distribution in synovial tissue from ligament trauma patients and MSC, PDKs may represent attractive selective metabolic targets for OA treatment. Moreover, targeting PDKs does not affect cells in a homeostatic, oxidative state. Our data provide an evidence-based rationale for the idea that inhibition of PDKs could restore the healthy THY1+ FLS phenotype. This approach may mitigate the progression of OA and thereby fundamentally change the clinical management of OA from the treatment of symptoms to addressing causes.

[Influence of the COVID-19 pandemic on the physiotherapeutic and medical follow-up care after reconstructions of the anterior cruciate ligament]. / Einfluss der COVID-19-Pandemie auf die physiotherapeutische und ärztliche Nachsorge nach Rekonstruktionen des vorderen Kreuzbandes.

BACKGROUND: The aim of this study was to examine the influence of the COVID-19(coronavirus disease 2019) pandemic on the medical and physiotherapeutic follow-up care after reconstructions of the anterior cruciate ligament. METHODS: 116 patients (72 men and 44 women) who had received a reconstruction of the anterior cruciate ligament between September 2019 and December 2020 were included in this study. These patients were divided into two groups depending on the date of surgery: one group that had received surgery in 2019 before the COVID-19 pandemic and one group that had undergone surgery in 2020 and was directly affected by the COVID-19 pandemic. All patients were interviewed using a standardized questionnaire regarding the influence of the coronavirus pandemic on the medical and physiotherapeutic follow-up care, as well as the moment of return to work. In addition, the range of motion of the respective knee 3 months postoperatively was analysed based on physical examination. RESULTS: At 3 months postoperatively, patients who had undergone surgery in 2020 showed a clear trend towards a higher frequency of extension deficits of ≥ 5° (18.8% vs. 4.3%, p = 0.097) or an inability to bend the knee ≥ 120° (23.3% vs. 10%, p = 0.197) compared to those who had received surgery in 2019. Patients who had undergone surgery in 2020 reported significantly longer delays for appointments, a higher number of futile attempts to get an appointment and a higher number of cancelled appointments, regarding both medical and physiotherapeutic follow-up care. 34.9% of the patients who received surgery in 2020 indicated that they were able to reduce the duration of their sick leave due to the increased possibilities of working in a home-office situation during the pandemic. Alternative treatment options due to the pandemic were offered by 13.3% of the physiotherapists and 12.2% of the physicians. CONCLUSION: Although the physiotherapeutic and medical follow-up care was not directly affected by a "lockdown", the pandemic led to significant restrictions, which are also reflected in a clear trend towards worse clinical outcomes. Consequently, a further expansion of alternative treatment options, which were only offered by 12-13% of practices and that are presumably of comparable relevance for various other diseases, is needed.

Relationship Between the OF Classification and Radiological Outcome of Osteoporotic Vertebral Fractures After Kyphoplasty.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The OF classification is a new classification for osteoporotic vertebral fractures. The aim of this study was to clarify the relationship between preoperative OF subgroups and the postoperative outcome after kyphoplasty in patients with such fractures. METHODS: Patients who underwent kyphoplasty of a single osteoporotic vertebral fracture were included and divided into groups according to the OF subgroups. Pre- and postoperative plain radiographs were analyzed in regard to the restoration of vertebral body height and local kyphotic angle (LKA). Additionally, clinical data including pre- and postoperative Visual Analogue Scale pain scores was documented. The clinical and radiological results were compared pre- and postoperatively within groups and between groups. RESULTS: A total of 156 patients from OF subgroups 2 to 4 were included (OF 2: n = 58; OF 3: n = 36; OF 4: n = 62). Patients from all groups experienced significant pain relief postoperatively (P < .001). Patients with OF 2 fractures showed a repositioning of the vertebral body height in the anterior and middle portions (both P < .001), but no significant improvement in LKA. For OF 3 and 4 fractures, there was a significant restoration of vertebral body height (P < .001 for both) and a significant improvement of LKA (P < .001 for both). The highest average restoration was noted in the OF 4 group. CONCLUSIONS: A higher OF subgroup is related to a higher radiological benefit from kyphoplasty. This confirms that the OF classification is an appropriate tool for the preoperative assessment of osteoporotic fractures.

Analysis of cartilage injury patterns and risk factors for knee joint damage in patients with primary lateral patella dislocations.

BACKGROUND: Lateral patellar dislocation (LPD) frequently causes damage to the knee. Injury patterns and risk factors contributing to such injuries have not yet been examined in detail. METHODS: We retrospectively analyzed 50 consecutive patients with primary LPD. Two reviewers evaluated the MRI images regarding risk factors for LPD (Dejours classification; Caton-Deschamps Index, CDI; distance from the tibial tuberosity to trochlear groove, TT-TG; trochlear depth, TD) as well as joint damages according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS). RESULTS: 33 male and 17 female patients with a mean age of 23.2 (±9.6) years were included in this study. 52% were classified Dejours ≥ B, 34% had a CDI ≥ 1.3, 22% a TT-TG ≥ 20mm and 52% a TD < 3mm. 49 out of 50 patients (98%) showed abnormalities according to WORMS. The most frequently observed abnormalities were synovitis/effusion (49/50, 98%), bone marrow oedema (44/50, 88%) and cartilage damage (42/50, 84%). Most frequently affected subregions were medial (41/50, 82%) and lateral (31/50, 62%) patella as well as the anterior (43/50, 86%), central (42/50, 84%) and posterior (11/50, 22%) portion of the lateral femoral condyle. There was no significant correlation between any of the examined risk factors and joint damages according to WORMS. Male patients had higher scores regarding total cartilage damage (5.11 vs. 2.56, p = 0.029), total score for the lateral femorotibial joint (3.15 vs. 1.65, p = 0.026) and overall total WORMS score (12.15 vs. 8.29, p = 0.038). CONCLUSION: Risk factors for LPD do not influence the risk of damages to the knee joint after primary LPD. Although LPD is generally known to affect more female than male patients, male patients suffered more severe injuries after primary LPD, particularly of the lateral femorotibial joint. Overall, our results underline the importance of MRI imaging after primary LPD.

In vivo analysis of hip joint loading on Nordic walking novices.

OBJECTIVE: To evaluate the influence of Nordic walking (NW) on hip joint loads in order to determine whether it can be safely performed during postoperative physiotherapy in patients after orthopeadic surgery of the hip. METHODS: Internal hip joint loads were directly measured in vivo in 6 patients using instrumented hip prostheses during NW and ordinary walking (OW). All patients received training in two different NW techniques (double-poling and the diagonal technique) by a certified NW instructor. Measurements were conducted on a treadmill at a speed of 4 km/h on level ground, at 10% inclination and at 10% slope as well as on a level lawn at a self chosen comfortable speed. Resultant contact force (Fres), bending moment (Mbend) and torsional torque (Mtors) were compared between NW and OW as well as between both NW techniques. RESULTS: Joint loads showed a double peak pattern during all setups. Neither NW technique significantly influenced hip joint loads at the time of the first load peak during contralateral toe-off (CTO), which was also the absolute load peak, in comparison to OW. Compared to OW, double-poling significantly reduced Fres and Mbend at the time of the second load peak during the contralateral heel strike (CHS) on level ground both on the treadmill (- 6% and - 7%, respectively) and on the lawn (- 7% and - 9%). At 10% inclination, the diagonal technique increased Fres and Mbend at CHS (by + 6% and + 7%), but did not increase the absolute load peak at CTO. CONCLUSION: Joint loads during NW are comparable to those of OW. Therefore, NW can be considered a low-impact activity and seems to be safe for patients that are allowed full weight bearing, e.g. during postoperative rehabilitation after THA.

Does obesity affect acetabular cup position, spinopelvic function and sagittal spinal alignment? A prospective investigation with standing and sitting assessment of primary hip arthroplasty patients.

BACKGROUND: Total hip arthroplasty (THA) instability is influenced by acetabular component positioning, spinopelvic function and sagittal spinal alignment. Obesity is considered as a risk factor of THA instability, but the causal relationship remains unknown. This study aimed to investigate the influence of BMI on (1) spinopelvic function (lumbar flexibility, pelvic mobility and hip motion), (2) sagittal spinal alignment pre- and postoperatively and (3) acetabular cup position postoperatively in primary THA patients in a prospective setting. METHODS: One hundred ninety patients receiving primary total hip arthroplasty were enrolled in a prospective cohort study and retrospectively analysed. All patients received stereoradiography (EOS) in standing and relaxed sitting position pre-and postoperatively. C7-sagittal vertical axis (C7-SVA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA) were assessed. Key parameters of the spinopelvic function were defined as lumbar flexibility (∆ LL = LLstanding - LLsitting), pelvic mobility (∆ PT = PTstanding - PTsitting) and hip motion (∆ PFA = PFAstanding - PFAsitting). Pelvic mobility was further defined based on ∆ PT as stiff, normal and hypermobile (∆ PT < 10°; 10°-30°; > 30°). The patients were stratified to BMI according to WHO definition: normal BMI ≥ 18.5-24.9 kg/m2 (n = 68), overweight ≥ 25.0-29.9 kg/m2 (n = 81) and obese ≥ 30-39.9 kg/m2 (n = 41). Post-hoc analysis according to Hochberg's GT2 was applied to determine differences between BMI groups. RESULTS: Standing cup inclination was significant higher in the obese group compared to the normal BMI group (45.3° vs. 40.1°; p = 0.015) whereas standing cup anteversion was significantly decreased (22.0° vs. 25.3°; p = 0.011). There were no significant differences for spinopelvic function key parameter lumbar flexibility (∆ LL), pelvic mobility (∆ PT) and hip motion (∆ PFA) in relation to BMI stratified groups. The obese group demonstrated significant enhanced pelvic retroversion compared to the normal BMI group (APPT - 1.8° vs. 2.4°; p = 0.028). The preoperative proportion of stiff pelvic mobility was decreased in the obese group (12.2%) compared to normal (25.0%) and overweight (27.2%) groups. Spinal sagittal alignment in C7-SVA and PI-LL mismatch demonstrated significantly greater imbalance in the obese group compared to the normal BMI group (68.6 mm vs. 42.6 mm, p = 0.002 and 7.7° vs. 1.2°, p = 0.032, respectively) The proportion of patients with imbalanced C7-SVA was higher in the obese (58.5%) than in the normal BMI group (44.1%). CONCLUSIONS: The significantly increased spinal sagittal imbalance with altered pelvic mechanics is a potential cause for the reported increased risk of THA dislocations in obese patients. Consequently, the increased spinal sagittal imbalance in combination with normal pelvic mobility need to be taken into account when performing THA in obese patients.

Is implant sonication useful when screening for infection in conversion of prior hip fracture fixation to total hip arthroplasty?

OBJECTIVE: To examine sonication results in presumed aseptic conversion total hip arthroplasty (THA) after hip fracture fixation and to evaluate its implications on the treatment outcome. METHODS: This retrospective cohort study reviewed the data from presumed aseptic patients that underwent conversion of prior internal fixation of proximal femoral fractures to THA between 2012 and 2018. Microbiological analysis was performed using sonication of osteosynthesis material and tissue samples. Treatment outcome including the occurrence of periprosthetic joint infection (PJI) was recorded. RESULTS: A total of 32 patients were included in the study. Of these, five patients (15.6%) had positive intraoperative cultures. The mean follow-up following conversion THA was 43.0 months (range, 19.0-91.5 months). Sonication was positive in three patients (9.4%), all of whom were deemed contaminated and did not develop PJI. Tissue cultures were positive in two patients (6.3%). One patient with Enterococcus faecalis received antibiotic treatment and did not develop PJI. Another patient with growth of Cutibacterium acnes that was initially classified as a contaminant later developed acute PJI caused by the same pathogen. Overall, PJI occurred in two patients (6.3%) after conversion THA. CONCLUSION: Sonication of internal fixation devices did not add diagnostic value in clinically aseptic conversion THA. Further studies are needed to better understand the relevance of unexpected positive cultures, and to develop diagnostic criteria for the management of these patients.

Dual-energy X-ray Absorptiometry Does Not Represent Bone Structure in Patients with Osteoporosis: A Comparison of Lumbar Dual-Energy X-Ray Absorptiometry with Vertebral Biopsies.

STUDY DESIGN: Prospective cross-sectional exploratory study. OBJECTIVE: To evaluate the correlation between in vivo lumbar dual-energy x-ray absorptiometry (DXA) and parameters of bone architecture in micro-computed tomography (micro-CT) in patients with osteoporosis. SUMMARY OF BACKGROUND DATA: DXA is the current diagnostic standard for evaluating osteoporosis. However, there are various concerns regarding its validity, especially in the spine. No study has so far investigated whether in vivo DXA correlates with the actual lumbar bone architecture. METHODS: Lumbar DXA scans were compared with micro-CT analysis of vertebral biopsies in patients with osteoporotic vertebral fractures (fracture group) and those without (control group). Preoperatively, all patients underwent a DXA scan (L1-L4). Intraoperative biopsies from nonfractured vertebrae (preferably L3) were analyzed by micro-CT regarding bone quantity and quality. The groups were compared regarding differences in DXA and micro-CT results. In each group, a correlation analysis was performed between DXA and micro-CT. RESULTS: The study included 66 patients (33 per group). Preoperative DXA results were worse in the fracture group than the control group (areal bone mineral density [aBMD] 0.95 vs. 1.31, T-score -1.97 vs. 0.92, each P < 0.001). Micro-CT analysis confirmed differences regarding quantitative parameters (bone/total volume: 0.09 vs. 0.12, P < 0.001) and qualitative parameters (connectivity index: 15.73 vs. 26.67, P < 0.001; structure model index: 2.66 vs. 2.27, P < 0.001; trabecular number: 2.11 vs. 2.28, P = 0.014) of bone architecture between both groups. The DXA results did not correlate with micro-CT parameters in the fracture group. In the control group, correlations were found for some parameters (bone/total volume vs. aBMD: r = 0.51, P = 0.005; trabecular number vs. aBMD: r = 0.56, P = 0.001). CONCLUSION: These data constitute the first comparison of DXA measurements with microstructural analysis of vertebral biopsies in patients with osteoporosis. Our results indicate that lumbar DXA neither qualitatively nor quantitatively represents microstructural bone architecture and is therefore not a reliable tool for the evaluation of bone quality in the spine.Level of Evidence: 3.

Musculature adaption in patients with lumbosacral transitional vertebrae: a matched-pair analysis of 46 patients.

OBJECTIVE: Even though lumbosacral transitional vertebrae (LSTV) are one of the most common congenital anomalies of the spine, their effect on surrounding soft tissues is not well-studied. We therefore aimed at analyzing the association between LSTV and changes in volume, mass, symmetry, and degeneration of lumbar and trunk muscles. MATERIALS AND METHODS: Abdomen-pelvis CT scans were analyzed in patients with LSTV and a matched control group. LSTV were classified according to the Castellvi classification. Muscles were segmented from the remaining soft tissue and their cross-sectional area and volume were examined at five defined levels. Threshold segmentation was used to differentiate between muscle fibers and fat tissue. Matched pairs were compared using Wilcoxon rank sum tests. For comparison of categorical data, chi-squared tests were performed and for associations between the degree of fusion and muscle size and degeneration, Spearman's correlation coefficients were calculated. Inter- and intrarater reliabilities were evaluated by computing intraclass correlation coefficients. RESULTS: Forty-six patients with LSTV and 46 controls were included. Muscle volume of the paraspinal and trunk muscles was significantly lower (707.0 cm3 vs. 809.7 cm3, p < 0.001) and fatty muscle changes were significantly increased in all but the caudal paravertebral muscles of LSTV patients (M. psoas p < 0.04, M. quadratus lumborum p < 0.001, paravertebral muscles p = 0.011, M. rectus abdominis p < 0.001, M. obliquus abdominis p < 0.001). Correlations between the degree of Castellvi classification and muscle volume were significant (p = 0.001). CONCLUSION: LSTV are associated with a reduction in muscle volume and an increase in muscle degeneration of both lumbar and trunk muscles.

Vertebral disk morphology of the lumbar spine: a retrospective analysis of collagen-sensitive mapping using dual-energy computed tomography.

OBJECTIVES: To investigate the diagnostic accuracy of collagen-sensitive maps derived from dual-energy computed tomography (DECT) for the detection of lumbar disk pathologies in a feasibility setting. MATERIALS AND METHODS: We retrospectively reviewed magnetic resonance imaging (MRI), computed tomography (CT), and DECT datasets acquired in patients who underwent periradicular therapy of the lumbar spine from June to December 2019. Three readers scored DECT collagen maps, conventional CT, and MRI for presence, type, and extent of disk pathology. Contingency table analyses were performed to determine diagnostic accuracy using MRI as standard of reference. Interrater agreement within and between imaging modalities was evaluated by computing intraclass correlation coefficients (ICCs) and Cohen's kappa. Correlation between sum scores of anteroposterior disk displacement was determined by calculation of a paired t test. RESULTS: In 21 disks in 13 patients, DECT had a sensitivity of 0.87 (0.60-0.98) and specificity of 1.00 (0.54-1.00) for the detection of disk pathology. Intermodality agreement for anteroposterior disk displacement was excellent for DECT (ICC 0.963 [0.909-0.985]) and superior to CT (ICC 0.876 [0.691-0.95]). For anteroposterior disk displacement, DECT also showed greater within-modality interrater agreement (ICC 0.820 [0.666-0.916]) compared with CT (ICC 0.624 [0.39-0.808]). CONCLUSION: Our data suggest that collagen-sensitive imaging has an added benefit, allowing more accurate evaluation of the extent of disk displacement with higher interrater reliability. Thus, DECT could provide useful diagnostic information in patients undergoing CT for other indications or with contraindications to MRI.

Burst fractures lead to a fracture-associated intervertebral vacuum phenomenon: a case series of 305 traumatic fractures of the thoracolumbar spine.

PURPOSE: Intervertebral vacuum phenomenon (IVP) is mainly seen as a sign of degenerative disc diseases. Although studies have shown that IVP also occurs after traumatic injuries to the spine, its clinical relevance in spinal fractures remains unknown. Therefore, the aim of this study was to analyse the prevalence, demographic parameters and fracture morphology in patients with fracture-associated IVP (FAVP) of the thoracolumbar spine. METHODS: In this retrospective cohort study, patients with traumatic fractures of the thoracolumbar spine who were admitted between January 2014 and December 2015 were included. CT scans were assessed for the presence of intervertebral areas of gaseous radiolucency, which were defined as IVP. Fractures were classified according to the AOSpine Thoracolumbar Spine Injury Classification System. Demographic and anamnestic data, including age, sex and trauma mechanism, were documented. RESULTS: A total of 201 patients with 305 fractures were included. Seventy-three patients with 98 fractures had follow-up CTs. Sixty-eight patients had IVP, of whom 46 patients had FAVP. On the follow-up CT, a significant correlation was found between A3 fractures and FAVP, while initial FAVP was significantly correlated with age and low-velocity trauma mechanisms. Initial degenerative IVP also showed a significant correlation with age. CONCLUSIONS: FAVP occurred significantly more often in burst fractures and therefore may lead to disc degeneration due to nutritional supply disturbances via the vertebral endplate. As surgical management strategies for burst fractures are intensively discussed, the appearance of FAVP should be taken in consideration.

Recruitment and Retention of Older People in Clinical Research: A Systematic Literature Review.

OBJECTIVE: To identify barriers and solutions for the recruitment and retention of older (aged ≥65 years) people in clinical trials. DESIGN: Systematic literature review. METHODS: Three databases (Medline, Embase, and CENTRAL) were searched for articles reporting on barriers or solutions regarding the recruitment or retention of older people. Only original research articles were included. RESULTS: Fifty eligible articles were identified. Exclusion criteria were the most common cause of poor recruitment of older adults (mainly age and comorbidities). Patients' families or physicians often advised against participation (22% of included studies). Lack of interest (18%) and problems with transportation (18%) were also commonly cited as challenges. Fourteen trials (28%) reported that monitoring and adapting their recruitment methods helped, along with a flexible research team (26%) and provision of transportation (24%). Retention was impaired by death (12%), illness (8%), and loss of interest (6%). Methods with a positive effect on retention included financial incentives and regular information about the progress of the study (12%), a low staff turnover (12%), flexibility in appointment making (10%), and expression of appreciation by the staff through letters, gifts, and cards to the participants (10%). CONCLUSION: We identified several barriers and have listed potential solutions that may improve recruitment and lead to fewer dropouts in trials involving older populations. Implementation of our findings may help mitigate the manifold challenges that come with running a trial with older people.

Bone structure determined by HR-MDCT does not correlate with micro-CT of lumbar vertebral biopsies: a prospective cross-sectional human in vivo study.

BACKGROUND: Osteoporosis is characterized by a deterioration of bone structure and quantity that leads to an increased risk of fractures. The primary diagnostic tool for the assessment of the bone quality is currently the dual-energy X-ray absorptiometry (DXA), which however only measures bone quantity. High-resolution multidetector computed tomography (HR-MDCT) offers an alternative approach to assess bone structure, but still lacks evidence for its validity in vivo. The objective of this study was to assess the validity of HR-MDCT for the evaluation of bone architecture in the lumbar spine. METHODS: We conducted a prospective cross-sectional study to compare the results of preoperative lumbar HR-MDCT scans with those from microcomputed tomography (µCT) analysis of transpedicular vertebral body biopsies. For this purpose, we included patients undergoing spinal surgery in our orthopedic department. Each patient underwent preoperative HR-MDCT scanning (L1-L4). Intraoperatively, transpedicular biopsies were obtained from intact vertebrae. Micro-CT analysis of these biopsies was used as a reference method to assess the actual bone architecture. HR-MDCT results were statistically analyzed regarding the correlation with results from µCT. RESULTS: Thirty-four patients with a mean age of 69.09 years (± 10.07) were included in the study. There was no significant correlation for any of the parameters (bone volume/total volume, trabecular separation, trabecular thickness) between µCT and HR-MDCT (bone volume/total volume: r = - 0.026 and p = 0.872; trabecular thickness: r = 0.074 and r = 6.42; and trabecular separation: r = - 0.18 and p = 0.254). CONCLUSION: To our knowledge, this is the first study comparing in vivo HR-MDCT with µCT analysis of vertebral biopsies in human patients. Our findings suggest that lumbar HR-MDCT is not valid for the in vivo evaluation of bone architecture in the lumbar spine. New diagnostic tools for the evaluation of osteoporosis and preoperative orthopedic planning are urgently needed.

Low sensitivity of histopathological examination of peri-implant tissue samples in diagnosing postoperative spinal implant infection.

AIMS: To evaluate the histopathological examination of peri-implant tissue samples as a technique in the diagnosis of postoperative spinal implant infection (PSII). METHODS: This was a retrospective analysis. Patients who underwent revision spinal surgery at our institution were recruited for this study. PSII was diagnosed by clinical signs, histopathology, and microbiological examination of intraoperatively collected samples. Histopathology was defined as the gold standard. The sensitivity for histopathology was calculated. A total of 47 patients with PSII and at least one microbiological and histopathological sample were included in the study. RESULTS: PSII occurred in approximately 28% of the study population. Histopathology showed a sensitivity of 51.1% in the diagnosis of PSII. The most commonly found pathogens were Cutibacterium acnes and gram-positive staphylococci. CONCLUSION: Histopathology has low sensitivity for detecting PSII. In particular, infections caused by low-virulence microorganisms are insufficiently detected by histopathology. Cite this article: Bone Joint J 2020;102-B(7):899-903.