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Osteoporosis is a risk factor for instrumentation failure in spine surgery. Bone strength is commonly assessed by bone mineral density (BMD) as a surrogate marker. However, BMD represents only a portion of bone strength and does not capture the qualitative dimensions of bone. Recently, the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score was introduced as a novel marker of bone quality. However, it is still unclear if the VBQ score correlates with in-vivo bone microstructure.The aims of the study were (1) to demonstrate differences in MRI-based (VBQ) and in-vivo (microcomputed tomography; μCT) bone quality between osteopenic/osteoporotic and normal bone, (2) to show the correlation between VBQ, bone microstructure and volumetric BMD (vBMD), and (3) to determine the predictive value of the VBQ score for the prevalence of osteopenia/osteoporosis.Retrospective cross-sectional study.267 patients who underwent posterior lumbar fusion surgery from 2014 to 2021 at a single academic institution. Bone biopsies were harvested intraoperatively in 118 patients.VBMD, VBQ score, and bone microstructure parameters derived from μCT.Quantitative computed tomography (QCT) measurements were performed at the lumbar spine and the L1/L2 average was used to categorize patients with a vBMD ≤120mg/cm267 patients (55.8% female, age 63.3 years, BMI 29.7 kg/mThis study demonstrated for the first time that the VBQ score is associated with trabecular microstructure determined by μCT. The bone microstructure and VBQ score were significantly different in patients with impaired vBMD. However, the ability to predict osteopenia/osteoporosis with the VBQ score was moderate. The VBQ score appears to reflect additional bone quality characteristics and might have a complementary role to vBMD. This enhances our understanding of the biological background of the radiographic VBQ score and might be a take-off point to evaluate the clinical utility of it as non-invasive screening tool for bone quality.

To investigate whether (1) there is a difference between patients with normal or sagittal spinal and spinopelvic malalignment in terms of their paraspinal muscle composition and (2) if sagittal malalignment can be predicted using muscle parameters.A retrospective review of patients undergoing posterior lumbar fusion surgery was conducted. A MRI-based muscle measurement technique was used to assess the cross-sectional area, the functional cross-sectional area, the intramuscular fat and fat infiltration (FI) for the psoas and the posterior paraspinal muscles (PPM). Intervertebral disc degeneration was graded for levels L1 to S1. Sagittal vertical axis (SVA; ≥ 50 mm defined as spinal malalignment), pelvic incidence (PI) and lumbar lordosis (LL) were measured, and PI-LL mismatch (PI-LL; ≥ 10° defined as spinopelvic malalignment) was calculated. A receiver operating characteristic (ROC) analysis was conducted to determine the specificity and sensitivity of the FIOne hundred and fifty patients were analysed. The PI-LL and SVA malalignment groups were found to have a significantly higher FISignificant differences in the muscle composition between normal and malalignment groups with respect to FI

The spread of the coronavirus disease has impacted healthcare systems worldwide; however, restrictions due to the SARS-CoV‑2 (severe acute respiratory syndrome coronavirus 2) pandemic are particularly drastic for physicians in residency training. Imposed restrictions interrupt the standard educational curricula, and consequently limited residents to meet mandatory requirements.The aim of this study was to evaluate the effects of the SARS-CoV‑2 pandemic on residency training in orthopedics and trauma surgery in Germany.An online-based, voluntary, and anonymous survey of physicians in residency training for orthopedics and trauma surgery was conducted. Through email lists of junior physician organizations the survey was sent to 789 physicians. Participation was possible between October and November 2021.A total of 95 participants (female 41.1%) with a mean age of 31.3 ± 2.8 years were analyzed. In the everyday clinical practice and care 80% of participants thought that they were set back in time of their general training due to the pandemic. There was an average reduction of 25.0% in time spent in the OR and 88.4% agreed that their surgical training was delayed due to the pandemic. Of the respondents 33.6% were able to attend external continuing education courses. Only 4.2% were able to invest more time in research and 55.8% of participants agreed that their residency training will be extended due to the pandemic.The COVID pandemic has had a significant impact on the residency training in orthopedics and trauma surgery in Germany. In almost all areas of training, residents had to accept restrictions due to the imposed restrictions, which potentially negatively affected their training.HINTERGRUND: Die Ausbreitung des Coronavirus hat die Gesundheitssysteme weltweit beeinflusst. Restriktionen aufgrund der SARS-CoV‑2(severe acute respiratory syndrome coronavirus 2)-Pandemie sind jedoch besonders einschneidend für ÄrztInnen in Weiterbildung. Auferlegte Restriktionen unterbrechen die vorgesehenen Ausbildungsetappen und führen zu möglicher Nichteinhaltung von obligaten Anforderungen. ZIEL: Ziel der Studie war es, die Effekte der SARS-CoV‑2-Pandemie auf die Facharztweiterbildung im Fachbereich Orthopädie und Unfallchirurgie (OU) in Deutschland auszuwerten.Eine online-basierte, freiwillige und anonyme Befragung von ÄrztInnen in Weiterbildung im Fachbereich OU wurde durchgeführt. Mittels E‑Mail-Verteiler von ärztlichen Nachwuchsorganisationen (Junges Forum O und U, Forum AGA Assistenzärzte) wurde die Umfrage an 789 ÄrztInnen gesendet. Die Teilnahme war zwischen Oktober und November 2021 möglich.Es wurden 95 Teilnehmer (w:41,1 %) mit einem Durchschnittsalter von 31,3 ± 2,8 Jahren analysiert. Im Klinikalltag denken 80 %, dass sie durch die Einschränkungen zeitlich zurückgeworfen wurden. Die Zeit der aktiven Teilnahme im OP reduzierte sich im Durchschnitt um 25,0 % und 88,4 % stimmten zu, dass sich ihre operative Ausbildung pandemiebedingt verzögern wird. Die Teilnahme an externen Fortbildungskursen war bei 33,6 % möglich. Nur 4,2 % konnten mehr Zeit in Forschung investieren. Insgesamt sind 55,8 % der Meinung, dass sich die Zeit der Facharztweiterbildung pandemiebedingt verlängert.Die COVID-19-Pandemie hat einen wesentlichen Einfluss auf die Facharztweiterbildung im Fachbereich OU in Deutschland. In fast allen Bereichen der Weiterbildung mussten AssistenzärztInnen aufgrund der auferlegten Restriktionen Einschränkungen hinnehmen, die ihre Weiterbildung potenziell negativ beeinflussten.

Lumbosacral transitional vertebrae (LSTV) are common congenital variances with a prevalence found in the population up to 35.6%. The literature demonstrates an influence of LSTV on bony pelvic anatomy. The influence on the anatomical acetabular orientation, which is important for cup positioning in total hip arthroplasty, has not yet been described for patients with LSTV. A total of 53 patients with LSTV were identified from a CT Database including 819 subjects. Fifty patients with LSTV could be included and were matched for age and sex against a control group. We examined the influence of LSTV, classified according to Castellvi, on acetabular orientation and pelvic tilt in the supine position. Functional acetabular anteversion and inclination, assessed against the table plane, were compared against anatomical acetabular anteversion and inclination, assessed against the anterior pelvic plane. The anatomical acetabular inclination correlated with the pelvic tilt (r = 0.363, p < 0.001). The anatomical acetabular inclination was significantly larger than the functional acetabular inclination in the supine position (p < 0.001). Castellvi grading of LSTV correlated negatively with pelvic tilt (ρ = −0.387, p = 0.006). Castellvi grading correlated significantly with functional acetabular anteversion (ρ = 0.324, p = 0.022) and anatomical acetabular anteversion (ρ = 0.306, p = 0.022). A higher Castellvi grading was accompanied by a reduced pelvic tilt in the supine position. The functional acetabular anteversion and anatomical acetabular anteversion increased in parallel to the higher Castellvi grading. Therefore, LSTV and Castellvi grading might be assessed on pre-operative X-rays prior to hip arthroplasty and surgeons might consider adjusting cup positioning accordingly.

Study Design: Retrospective matched-pair analysis. Objectives: Lumbosacral transitional vertebrae (LSTV) have a reported prevalence of 4-36% in the population. The safe zones for screw placement for spinopelvic fusion in adult spinal deformity surgery for patients with LSTV have not been described in the literature. Our study aimed to assess the safety of S1-pedicle screw (S1PS), S2-alar screw (S2AS), S2-alar-iliac screw (S2AIS), and iliac screw (IS) placement in patients with LSTV. Methods: Out of the 819 examined patients, 49 patients with LSTV were included in our retrospective analysis with a matched pair control group. We used the 3-dimensional planning tool mediCAD for screw placement of S1PS, S2AS, S2AIS, IS with different angles, length and diameters. Results: We evaluated a total of 10 192 screw trajectories. No serious complications occurred due to the trajectories used for S1PS. LSTV increased the risk of vessel injury for S2AS trajectories ( P = .001) but not for S2AIS ( P = .526). Besides the presence of an LSTV, the screw trajectory had a major influence on the frequency of serious complications. Conclusions: Sacral anchoring of long spinal constructions using S1PS, S2AS, S2AIS and IS is also possible in the presence of LSTV. For S2AS the trajectory with 30° lateral and caudal angulation of 10° showed the least vascular injuries and the least sacro-iliac-joint violations in patients with LSTV. S2AIS trajectories with 40° lateral and 0° sagittal angulation reduced the risk of serious complications in our patients collective with LSTV.

The concept of sagittal spinal malalignment is well established in spinal surgery. However, the effect of musculature on its development has not been fully considered and the position of the pelvis is mostly seen as compensatory and not necessarily a possible cause of sagittal imbalance.This study aimed to investigate the influence of the posterior paraspinal muscles (PPM, erector spinae, and multifidus) and the psoas muscle on spinopelvic and spinal alignment.Retrospective cross-sectional study.Patients undergoing posterior lumbar fusion between 2014 and 2021 for degenerative conditions at a tertiary care center, with preoperative lumbar magnetic resonance imaging (MRI) within 12 months prior the surgery and a preoperative whole spine radiograph were included.PPM and psoas muscle measurements including the cross-sectional area (CSA), the functional cross-sectional area (fCSA), the amount of intramuscular fat (FAT), and the percentage of fat infiltration (FI). Spinopelvic measurements including lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), and sagittal vertical axis (SVA).A T2-weighted MRI-based quantitative assessment of the CSA, the fCSA and the amount FAT was conducted, and FI was further calculated. The regions of interest included the psoas muscle and the PPM on both sides at the L4 level that were summarized and normalized by the patient's height (cmA total of 150 patients (53.3% female) were included in the final analysis with a median age of 65.6 years and a median BMI of 28.2 kg/mThis study demonstrated the potential role of posterior paraspinal muscles and psoas muscle on pelvic retroversion and elucidated the relation to sagittal spinal malalignment. Although we cannot establish causality, we propose that increasing FI

Purpose The pathogenic mechanism of the hip–spine syndrome is still poorly elucidated. Some studies have reported a reduction in low back pain after total hip arthroplasty (THA). However, the biomechanical mechanisms of THA acting on the lumbar spine are not well understood. The aim of the study is to evaluate the influence of THA on (1) the lumbar lordosis and the lumbar flexibility and (2) the lumbar intervertebral disc height. Methods A total of 197 primary THA patients were prospectively enrolled. Pre- and post-operative biplanar stereoradiography was performed in standing and sitting positions. Spinopelvic parameters (lumbar lordosis (LL), pelvic tilt, sacral slope, pelvic incidence), sagittal spinal alignment (sagittal vertical axis, PI-LL mismatch (PI-LL)) and lumbar disc height index (DHI) for each segment (L1/2 to L5/S1) were evaluated. The difference between standing and sitting LL (∆LL = LLstanding − LLsitting) was determined as lumbar flexibility. Osteochondrosis intervertebralis was graded according to Kellgren and Lawrence (0–4), and patients were assigned to subgroups (mild: 0–2; severe: 3–4). Results Lumbar flexibility increased significantly after THA (pre: 22.04 ± 12.26°; post: 25.87 ± 12.26°; p LL in standing (pre: 51.3 ± 14.3°; post: 52.4 ± 13.8°; p p = 0.01). ∆LL increased significantly in both subgroups stratified by osteochondrosis (pre/post: ΔLLmild: 25.4 (± 11.8)/29.4 ± 12.0°; p LLsevere: 17.5 (± 11.4)/21.0 ± 10.9°; p = 0.003). The DHI increased significantly from pre-operatively to post-operatively in each lumbar segment. PI-LL mismatch decreased significantly after THA (pre: 3.5°; post: 1.4°; p Conclusion The impact of THA on the spinopelvic complex was demonstrated by significantly improved lumbar flexibility and a gain in post-operative disc height. These results illustrate the close interaction between the pelvis and the vertebral column. The investigation provides new insights into the biomechanical patterns influencing the hip–spine syndrome.

Background: Lumbo-sacral transitional vertebrae (LSTV) are one of the most common congenital variances of the spine. They are associated with an increased frequency of degeneration in the cranial adjacent segment. Hypermobility and concomitant increased loads are discussed as a possible reason for segmental degeneration. We therefore examined the lumbar and segmental motion distribution in patients with LSTV with flexion-extension radiographs. Methods: A retrospective study of 51 patients with osteochondrosis L5/S1 with flexion and extension radiographs was performed. Of these, 17 patients had LSTV and were matched 1:1 for age and sex with patients without LSTV out of the collective of the remaining 34 patients. The lumbar and segmental range of motion (RoM) by segmental lordosis angle and the segmental wedge angle were determined. Normal distribution of parameters was observed by Kolmogorov-Smirnov-test. Parametric data were compared by paired T-test. Non-parametric data were compared by Wilcoxon-rank-sum-test. Correlations were observed using Spearman’s Rank correlation coefficient. A p-value

Lumbosacral transitional vertebrae (LSTV) are common congenital variances with a prevalence found in the population up to 35.6%. The literature demonstrates an influence of LSTV on bony pelvic anatomy. The influence on the anatomical acetabular orientation, which is important for cup positioning in total hip arthroplasty, has not yet been described for patients with LSTV. A total of 53 patients with LSTV were identified from a CT Database including 819 subjects. Fifty patients with LSTV could be included and were matched for age and sex against a control group. We examined the influence of LSTV, classified according to Castellvi, on acetabular orientation and pelvic tilt in the supine position. Functional acetabular anteversion and inclination, assessed against the table plane, were compared against anatomical acetabular anteversion and inclination, assessed against the anterior pelvic plane. The anatomical acetabular inclination correlated with the pelvic tilt (r = 0.363, p < 0.001). The anatomical acetabular inclination was significantly larger than the functional acetabular inclination in the supine position (p < 0.001). Castellvi grading of LSTV correlated negatively with pelvic tilt (rho = -0.387, p = 0.006). Castellvi grading correlated significantly with functional acetabular anteversion (rho = 0.324, p = 0.022) and anatomical acetabular anteversion (rho = 0.306, p = 0.022). A higher Castellvi grading was accompanied by a reduced pelvic tilt in the supine position. The functional acetabular anteversion and anatomical acetabular anteversion increased in parallel to the higher Castellvi grading. Therefore, LSTV and Castellvi grading might be assessed on pre-operative X-rays prior to hip arthroplasty and surgeons might consider adjusting cup positioning accordingly.

Zusammenfassung Hintergrund und Ziele Das deutsche Gesundheitssystem wurde mit Beginn der SARS-CoV-2-Pandemie auf die Behandlung von COVID-19-Patienten ausgerichtet. Dies ging mit der Aussetzung des operativen Elektivprogramms einher. Ziel der Studie war es, den Einfluss der SARS-CoV-2-Pandemie auf die Allgemein- und Viszeralchirurgie der Universitätskliniken in Deutschland zu untersuchen. Methoden Die vorliegende Querschnittsstudie basiert auf einer anonymen Umfrage, die vom 03.04.2020 bis zum 17.04.2020 für die Teilnehmer des Konvents der Ordinarien für Allgemein- und Viszeralchirurgie in Deutschland online zugänglich war. 73 % (n = 29/40) der Befragten nahmen teil. Ergebnisse Die Zusammenarbeit mit den Behörden und der Krankenhausleitung wurde überwiegend als angemessen empfunden. Allerdings stimmten nur 3 % (1/29) bzw. 7 % (2/29) der Aussage voll zu, dass sich die Gesundheitsbehörden auf Bundes- bzw. Landesebene unterstützend gegenüber der Allgemein- und Viszeralchirurgie zeigten. Die Klinikdirektoren erwarten einen niedrigeren Umsatz von durchschnittlich 28 ± 16 %. Es kam zu einer durchschnittlichen Verringerung der Betten- bzw. Operationssaalkapazität um 38 % bzw. 45 %. Darüber hinaus wurden 11 % des ärztlichen Personals der Allgemein- und Viszeralchirurgie in andere Abteilungen umverteilt. Diskussion Die SARS-CoV-2-Pandemie hat deutliche Auswirkungen auf die universitäre Allgemein- und Viszeralchirurgie in Deutschland. Die Reduktion der Betten- sowie der Operationsaalkapazität kann zu erheblichen Verzögerungen dringlicher Operationseingriffe und finanziellen Belastungen im Jahr 2020 und den Folgejahren führen.

A prospective observational study, level of evidence 3.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.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.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.A significant difference in spinopelvic parameters was detected in the preoperative to postoperative comparison (SS, PT, APPT, and PFA; Plt;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.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.

This was a prospective observational study.This investigation aimed (1) to determine the impact of sagittal spinal alignment with C7-sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL) mismatch and Roussouly classification on individual segments of spinopelvic mobility represented by lumbar flexibility [∆lumbar lordosis (LL)], pelvic mobility [∆pelvic tilt (PT)], and hip motion [∆pelvic femoral angle (PFA)] and (2) to assess the influence of coronal spinal balance on the spinopelvic complex in patients undergoing total hip arthroplasty (THA) preoperatively and postoperatively.Restricted spinopelvic mobility gained attention as a contributing factor for THA instability. However, it remains unclear what influence the coronal and sagittal spinal alignment has on spinopelvic mobility.A total of 197 THA patients were included in the investigation conducting biplanar stereoradiography in standing and sitting position preoperatively and postoperatively. Two independent investigators assessed C7-SVA (≤50 mm balanced,50 mm imbalanced), PI-LL (≤10 degrees balanced,10 degrees imbalanced), refounded Roussouly classification, coronal spinal balance with C7-central sacral vertical line, LL, pelvic incidence (PI), PT, PFA. Individual segments of spinopelvic mobility based on the change from standing to sitting were defined as ∆LL, ∆PT, and ∆PFA. Unpaired t test or Welch t test for comparison between groups of 2 was applied. Analysis of variance and post hoc analysis according to Bonferroni or Games-Howell was used to determine differences between groups of2. The Spearman rank correlation coefficient was used to determine the interrater reliability of the radiographic measurements.Significant differences were demonstrated for ∆LL (SVA balanced/imbalanced: 24.7 degrees/19.1 degrees, P =0.001; PI-LL balanced/imbalanced: 24.4 degrees/16.4 degrees, P0.000), PT (SVA balanced/imbalanced: 12.5 degrees/15.2 degrees, P =0.029; PI-LL balanced/imbalanced: 10.8 degrees/20.5 degrees, P0.000), PI (SVA balanced/imbalanced: 52.9 degrees/56.9 degrees, P =0.001; PI-LL balanced/imbalanced: 52.1 degrees/61.0 degrees, P0.000), LL (SVA balanced/imbalanced: 54.8 degrees/47.8 degrees, P =0.029; PI-LL balanced/imbalanced: 55.3 degrees/42.6 degrees, P0.000). The coronal spinal balance (central sacral vertical line) indicated no significant differences regarding spinopelvic mobility between positive, neutral, or negative balanced groups. Significant differences with decreased pelvic mobility (∆PT) and lumbar flexibility (∆LL) in low-grade PI types 1 and 2 compared with high-grade PI type 4 according to the Roussouly classification were observed.This is the first study to investigate spinal sagittal alignment using 3 different classifications in association to the spinopelvic complex in THA patients preoperatively and postoperatively. The significantly altered spinopelvic mechanics with decreased lumbar flexibility and increased pelvic retroversion in sagittal imbalanced patients clearly indicate the need for a separate consideration of the global spinal sagittal alignment. Our findings emphasize the importance of risk stratification for THA candidates in terms of sagittal imbalance attempting to mitigate the THA instability risk with accurate preoperative planning.Level III.

Objectives Ischemia-reperfusion injury is correlated with a substantial inflammatory response. Inflammation triggers the migration of cells through vessel endothelium and leads to serious tissue injury. Our hypothesis was that an early application of mammalian target of rapamycin inhibitors has an impact on human vessels after ischemia-reperfusion injury. Materials and methods After exposure to ischemia for 5 hours, human vessels (veins and arteries) from 20 patients were reperfused for 120 minutes in an in vitro bioreactor with heparinized human blood after oxygenation and warming to 37 °C. The vessels were treated with mammalian target of rapamycin inhibitor everolimus (5 ng/mL, n = 7) or sirolimus (10 ng/mL, n = 6). As a control group, untreated human vessels were reperfused (n = 7). During the reperfusion period, blood samples were collected continuously (after 0, 15, 30, 60, 120 minutes); vessel biopsies were performed at the end. Oxygen consumption was measured during reperfusion to determine vessel viability. Inflammatory markers (interleukin 6, tumor necrosis factor α, vascular endothelial growth factor) were analyzed in blood samples. To quantify vascular inflammation, we investigated the expression of CD11 and CD31. Results Physiological oxygen consumption and pH values verified vessel viability. After reperfusion, interleukin 6 and vascular endothelial growth factor levels were significantly increased in the control group over time, whereas everolimus and sirolimus showed no significant differences. Furthermore, tumor necrosis factor α level increased significantly in the sirolimus group, whereas the everolimus and control groups showed constant values. A significant decrease of expression of CD11b and CD31 in both mammalian target of rapamycin inhibitor cohorts compared with control cohort was investigated. Conclusions Early use of mammalian target of rapamycin inhibitors may limit an inflammatory rise of interleukin 6 and vascular endothelial growth factor after ischemia-reperfusion injury and could be associated with a restriction in vascular cell transmigration.

BACKGROUND Abnormal spinopelvic mobility is identified as a contributing element of total hip arthroplasty (THA) instability. Preoperative identification of THA patients at risk is still a remaining challenge. We therefore conducted this study to (1) evaluate if preoperative and postoperative spinopelvic mobility differs, (2) determine the interactions between the elements of the spinopelvic complex, and (3) identify preoperative parameters for predicting spinopelvic mobility. METHODS A prospective observational study assessing 197 THA patients was conducted with biplanar stereoradiography in standing and relaxed sitting positions preoperatively and postoperatively. Two independent investigators determined spinopelvic mobility based on 2 different classifications (Δ sacral slope [SS] and Δ pelvic tilt [PT]; Δ from standing to sitting; Δ 30° hypermobile). Multiple regression analysis and receiver operating characteristic analysis were used to identify predictors for postoperative spinopelvic mobility. RESULTS Spinopelvic mobility significantly increased after THA based on ΔPT (Pre/Post: 18.5°/22.8°; P < .000) and ΔSS (Pre/Post 17.9°/22.4°; P < .000). A distinct shift in the ratio from stiff (Pre/Post: 24%/9.7%) to hypermobile (Pre/Post: 10.2%/22.1%) mobility postoperatively was observed. Receiver operating characteristic analysis predicted postoperative stiffness using preoperative PTStanding ≥ 13.0° with a sensitivity of 90% and a specificity of 51% and hypermobility with preoperative SSStanding ≥ 35.2° with a sensitivity of 81% and a specificity of 34%. Age at surgery, preoperative PTStanding, and pelvic incidence were independent predictors of spinopelvic mobility (R2 = 0.24). CONCLUSION Definition of preoperative stiffness should be interpreted with caution by arthroplasty surgeons as mobility itself is influenced by THA. For the first time thresholds for standing preoperative parameters for predicting postoperative spinopelvic mobility could be provided. For preoperative standing only lateral assessment could serve as a screening tool for spinopelvic mobility.

Background The purpose of the present study was to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on orthopaedic and trauma surgery departments in university hospitals in Germany in order to clarify current challenges. Methods In this cross-sectional study, an online-based anonymous survey was conducted within the Convention of University Professors of Orthopaedic and Trauma Surgery in Germany from April 3 to April 11, 2020. A bipolar 5-point Likert scale (with possible responses of "totally disagree," "rather disagree," "neutral," "rather agree," and "totally agree") was applied. Fifty-two (69.3%) of 75 clinic directors participated. Results Communication and cooperation with the government, hospital administration, and other departments during the COVID-19 pandemic were mainly perceived as appropriate. However, only 7 respondents (13.7%) totally agreed or rather agreed with the statement that the authorities are supporters of orthopaedic and trauma surgery departments. Substantial financial and personnel changes in orthopaedic and trauma surgery departments of university hospitals were reported, resulting in an average reduction of 49.4% in operating room capacity and an expected 29.3% loss of revenue. In addition, 14.7% of physicians were reallocated from orthopaedic and trauma surgery to other care-delivery environments. Conclusions Our study demonstrated that the COVID-19 pandemic has had a substantial impact on orthopaedic and trauma surgery departments in German university hospitals. Distinct structural and financial effects were noted. Nevertheless, the present study demonstrates the commitment of our specialty to overcome the pandemic by providing competent personnel as well as close cooperation with the hospital administration and other departments. Clinical relevance To our knowledge, this is the first Germany-wide survey among the heads of orthopaedic and trauma surgery departments in university hospitals on the impact of the COVID-19 pandemic. The survey results may help to inform system-wide decision-making in Germany, in Europe, and beyond.