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European journal of trauma and emergency surgery 48(6), 4385-4402 (2022). doi:10.1007/s00068-022-01978-z special issue: "Focus On Distal Radius Fractures", Published by Springer Medizin, Heidelberg

Introduction In septic two-stage revision surgery, success depends on numerous factors. Key steps are the procedure of ex- and reimplantation and the choice of spacer in the interim phase. The latter is still a matter of debate. Recently, we showed the microbial non-inferiority of a spacer technique using prosthetic cemented implants with an individualized antibiotic mixture in the cement applying a mechanically inferior cementation method. The aim of the present study was to evaluate the clinical results of these spacers in view of either an endofemoral or a transfemoral procedure. Materials and methods Our collective consisted of 86 patients (45 endofemoral and 41 transfemoral procedures). The collective was analyzed with respect to complications, reinfection rate and clinical status at the end of the interim phase. Results of an endofemoral and transfemoral approach were compared. Results With a median Staffelstein-Score of 60 (range 31–81) at the end of the interim phase, the first clinical results are promising. The reinfection-free rate after a median follow-up of 50 months was 90%. Spacer-related complications occurred in 8% of the total collective. Comparing the endo- and transfemoral procedure, there were no statistical differences in complications or regarding the clinical and infectiological outcome. Conclusions In this study, we were able to show good clinical results for the presented spacer technique. With no relevant difference in outcome, the decision for an endofemoral or transfemoral technique can be based on technical deliberations. Further prospective comparative studies are necessary to show the clinical benefit of this procedure.

Knee surgery, sports traumatology, arthroscopy (2022). doi:10.1007/s00167-022-07212-y, Published by Springer, Berlin

OBJECTIVE: This study aims to develop and evaluate a simple tool for daily practice that might allow a rough estimate of individual braking performance (brake response time, BRT) of patients with osteoarthritis or those with arthroplasty of the knee or hip. METHODS: In this cross-sectional study, we examined 162 patients (72 men, 90 women; mean age = 64±12.8 years) who suffered from osteoarthritis of the knee (n=45) or hip (n=64) or who underwent a total hip (n=37) or knee (n=16) arthroplasty. BRT of each patient was measured in a brake simulator. The results were compared to demographic data, various clinical tests, and pain surveys. From these data, a multiple linear regression model was developed. RESULTS: From the observed correlations, the regression model consisted of age (correlation with BRT τ=0.176, p=0.001), sex (τ=0.361, p

Background Numerous classification systems have been proposed to interpret lumbar MRI scans. The clinical impact of the measured parameters remains unclear. To evaluate the clinical significance of imaging results in patients with multisegmental degenerative pathologies, treating specialists can perform image-guided local injections to target defined areas such as the epidural space. Objective The aim of this retrospective study was to evaluate the correlation between lumbar spinal stenosis measurements obtained by MRI and improvement obtained through local epidural injection. Methods In this retrospective study various measurement and classification systems for lumbar spinal stenosis were applied to MRI scans of 100 patients with this pathological condition. The reported effect of epidural bupivacaine/triamcinolone injections at the site was recorded in these patients and a comparative analysis performed. Results MRI features assessed in this study did not show any relevant correlation with reported pain relief after epidural injection in patients with chronic lumbar stenosis, with the exception of posterior disc height with a weak Kendall's tau of -0.187 (p= 0.009). Conclusions Although MRI is crucial for evaluating lumbar spinal stenosis, it cannot replace but is rather complementary to a good patient history and clinical examination or the results of local diagnostic injections.

During osteoarthritis, chondrocytes change their spatial arrangement from single to double strings, then to small and big clusters. This change in pattern has recently been established as an image-based biomarker for osteoarthritis. The pericellular matrix (PCM) appears to degrade together alongside cellular reorganization. The aim of this study was to characterize this PCM-degradation based on different cellular patterns. We additionally wanted to identify the earliest time point of PCM-breakdown in this physiopathological model. To this end, cartilage samples were selected according to their predominant cellular pattern. Qualitative analysis of PCM degradation was performed immunohistochemically by analysing five main PCM components: collagen type VI, perlecan, collagen type III, biglycan, and fibrillin-1 (n = 6 patients). Their protein content was quantified by enzyme-linked immunosorbent assay (127 patients). Accompanying spatial cellular rearrangement, the PCM is progressively destroyed, with a pericellular signal loss in fluorescence microscopy for collagen type VI, perlecan, and biglycan. This loss in protein signal is accompanied by a reduction in total protein content from single strings to big clusters (P < .001 for collagen type VI, P = .003 for perlecan, and P < .001 for biglycan). As a result of an increase in the number of cells from single strings to big clusters, the amount of protein available per cell also decreases for collagen type III and fibrillin-1, where total protein levels remain constant. Biochemical changes of the PCM and cellular rearrangement are thus highly interconnected hallmarks of osteoarthritis. Interestingly, the earliest point in time for a relevant PCM impairment appears to be at the transition to small clusters.

The goal of this study was to compare operative outcomes after lesser toe deformity correction with either proximal interphalangeal (PIP) joint arthrodesis or PIP joint resection arthroplasty. A prospective randomized controlled trial was performed with 37 patients (48 toes) operated on with one of these two procedures. Evaluation of the numeric rating scale score, the American Orthopedic Foot and Ankle Society score, osseous consolidation, and clinical outcome was performed preoperatively and at 6 weeks and 6 months postoperatively. Both study groups showed significant improvement at 6 months postoperatively. Although osseous consolidation was significantly higher for the arthrodesis group ( P =.001), this difference did not affect clinical outcomes, and at 6 months postoperatively, pain on the numeric rating scale was 0 (range, 0–7) for the arthroplasty group and 0 (range, 0–5) for the arthrodesis group ( P =.669). The American Orthopedic Foot and Ankle Society score was 83 (range, 39–95) and 80 (range, 59–95), respectively ( P =.879). No difference was observed for signs of inflammation or axis correction. Even a direct comparison of toes with radiologically osseous fusion (n=16) with those without fusion (n=32) did not show any clinical differences. This randomized controlled study showed no clinical differences in outcome between PIP joint arthrodesis and PIP joint resection arthroplasty for correction of lesser toe deformities, with good to excellent outcomes for both groups. [ Orthopedics . 2022;45(2):86–90.]

Archives of orthopaedic and trauma surgery 142(11), 3157-3164 (2022). doi:10.1007/s00402-021-03932-x, Published by Springer, Berlin ; Heidelberg

Cancers 14(11), 2694 (2022). doi:10.3390/cancers14112694 special issue: "Special Issue "Soft and Hard Tissue Sarcoma—Current and Future Concepts in Diagnosis and Treatment" / Special Issue Editor: Prof. Dr. Justus P. Beier, Guest Editor", Published by MDPI, Basel

Malignant melanoma is the most lethal form of skin cancer; its incidence has increased over the last five decades. Y-box binding protein 1 (YB-1) plays a prominent role in mediating metastatic behavior by promoting epithelial-to-mesenchymal transition (EMT) processes. Migratory melanoma cells exhibit two major phenotypes: elongated mesenchymal or rounded amoeboid. The actomyosin cytoskeleton is key in both phenotypes, but intermediate filaments also undergo a significant rearrangement process, switching from cytokeratin-rich to vimentin and nestin-rich network. In this study, we aimed to investigate to what extent YB-1 impacts the biomechanical (cell stiffness) and biochemical aspects of melanoma cells and their cytoskeleton. To this end, we subjected A375 YB-1 knock-out and parental cells to atomic force microscopy investigations (stiffness determination), immunolabelling, and proteome analysis. We found that YB-1 expressing cells were significantly stiffer compared to the corresponding YB-1 knock-out cell line. Proteomic analysis revealed that expression of YB-1 results in a strong co-expression of nestin, vimentin, fascin-1, and septin-9. In the YB-1 knock-out nestin was completely depleted, but zyxin was strongly upregulated. Collectively, our results showed that YB-1 knock-out acquires some characteristics of mesenchymal phenotype but lacks important markers of malignancy and invasiveness such as nestin or vimentin. We posit that there is an association of YB-1 expression with an amoeboid phenotype, which would explain the increased migratory capacity.

PURPOSE To assess whether reaction time (RT) and movement time (MT), as the two components of the total brake response time (TBRT) and brake force (BF) are different in patients with a foot joint arthrodesis in comparison to controls. METHODS The study was a comparative case series in a driving simulator under realistic driving conditions. Mobile patients without a walker, ≥6 months after surgery who were driving a car and had no neurological co-morbidity, knee or hip joint prosthesis were included in the study. The selection criteria resulted in 12 patients with right tibiotalar joint arthrodesis (TTJA) and 12 patients with another right foot joint arthrodesis (OFJA), who were compared to 17 individuals without any ankle-joint pathology. For TBRT, an empirical safe driving threshold of 700 ms was used. The outcome measures were RT, MT, TBRT, BF and McGuire score. RESULTS MT (p = 0.034) and TBRT (p = 0.026) were longer in TTJA patients in comparison with the controls. Also, more patients with TTJA than patients with OFJA and controls exceeded the safe driving threshold (p = 0.028). The outcomes in OFJA patients and in controls were comparable. The McGuire score was similar between the TTJA and OFJA patients (p = 0.26). CONCLUSIONS Significantly slower MT and TBRT, and significantly more patients exceeding the safe driving threshold, were observed after a tibiotalar-joint arthrodesis in comparison to the controls. Patients with OFJAs were not significantly different from the controls. Driving and emergency braking may be impaired after tibiotalar-joint arthrodesis.

Purpose: Numerous classification systems have been proposed to analyze lumbar spine MRI scans. When evaluating these systems, most studies draw their conclusions from measurements of experienced clinicians. The aim of this study was to evaluate the impact of specific measurement training on interobserver reliability in MRI classification of the lumbar spine. Methods: Various measurement and classification systems were assessed for their interobserver reliability in 30 MRIs from patients with chronic lumbar back and sciatic pain. Two observers were experienced spine surgeons. The third observer was an inexperienced medical student who, prior to the study measurements, in addition to being given the detailed written instructions also given to the surgeons, obtained a list of 20 reference measurements in MRI scans from other patients to practice with. Results: Excellent agreement was observed between the medical student and the spine surgeon who had also created the reference measurements. Between the two spine surgeons, agreement was markedly lower in all systems investigated (e.g., antero-posterior spinal canal diameter intraclass correlation coefficient [ICC] [3.1] = 0.979 vs. ICC [3.1] = 0.857). Conclusion: These data warrant the creation of publicly available standardised measurement examples of accepted classification systems to increase reliability of the interpretation of MR images.

OBJECTIVE To investigate if testing in a brake simulator can be replaced by a simple reaction timer setup imitating the ergonomic conditions of emergency braking when evaluating the ability to drive in patients with musculoskeletal problems of the lower extremities. METHODS A cross-sectional survey was performed in the Department of Orthopaedic Surgery in our University Hospital from October 2014 until May 2015. Patients attending our department with either osteoarthritis or arthroplasty of the knee or hip were asked to participate in the study if they had a valid driving license. The age limit was from 18 to 85 years. Both women and men were included. Registered demographic data were patient age, height, sex, body weight, and body mass index. Braking performance (brake response time [BRT]) was evaluated in a brake simulator that was embedded into a real car cabin (10 measurements). The values obtained were compared with those registered when simply testing (5 measurements) those patients with a normal reaction timer setup that imitated the sitting position in a car. Kendall's tau correlation coefficient was calculated between the values obtained from the brake simulator with those from the reaction timer setup. RESULTS Altogether, 137 patients (median age 67 years [range, 24-89 years]) with either osteoarthritis of the knee (n = 55) or hip (n = 82) were tested. Age was comparable in both collectives (P = 0.807). The mean body height was 1.70 m in both groups. Knee patients presented with a higher body weight of approximately 5 kg (P = 0.014) and consequently also had a higher body mass index (P = 0.023). The median BRT in the brake simulator was 628 ms (range, 390-1444 ms) for all subjects: 592 ms (range, 418-1146 ms) in the hip group and 696 ms (range, 390-1444 ms) in the knee group. Measurement values obtained by the reaction timer were significantly (P < 0.001) higher by approximately 15% (SD, 22%) than those measured in the brake simulator. A moderate correlation was found between the reaction timer and the brake simulator, with a Kendall's tau of 0.449 (P < 0.001) for all patients. Interestingly, hip patients showed a higher correlation (τ = 0.471) than knee patients (τ = 0.263). CONCLUSION Even though the measured correlations do not allow us to make a definite statement concerning braking performance, especially in knee patients, a simple reaction timer test can provide a low-cost first estimate of BRT for patients and their treating physicians. For forensic statements, the brake simulator will, however, remain the gold standard.

Intervertebral disc (IVD) degeneration is a leading cause of low back pain and it entails a high degree of impairment for the affected individuals. To decode disc degeneration and to be able to develop regenerative approaches a thorough understanding of the cellular biology of the IVD is essential. One aspect of this biology that still remains unanswered is the question of how cells are spatially arranged in a physiological state and during degeneration. The biological properties of the IVD and its availability make this tissue difficult to analyze. The present study investigates spatial chondrocyte organization in the anulus fibrosus from early embryonic development to end-stage degeneration. An optical sectioning method (Apotome) is applied to perform high resolution staining analyses using bovine embryonic tissue as an animal model and human disc tissue obtained from patients undergoing spine surgery. From a very high chondrocyte density in the early embryonic bovine disc, the number of cells decreases during gestation, growth, and maturation. In human discs, an increase in cellular density accompanied the progression of tissue degeneration. As had already been demonstrated in articular cartilage, cluster formation represents a characteristic feature of advanced disc degeneration.

Background context Low back pain is commonly attributed to intervertebral disc (IVD) degeneration. IVD resembles articular cartilage in its biochemical and cellular composition in many ways. For articular cartilage, degeneration stage-specific characteristic spatial chondrocyte patterns have recently been described. Purpose This study addresses how spatial chondrocyte organization in the IVD changes from early embryonic development to end stage degeneration. Study design Ex vivo immunohistochemical analysis. Methods We immunohistochemically investigated bovine IVD-tissue (n=72) from early embryonic development to early disc degeneration and human adult IVD-tissue (n=25) operated for trauma or degeneration for cellular density and chondrocyte spatial organization. IVD samples were sectioned along the main collagen fiber orientation. Nuclei were stained with DAPI and their number and spatial patterns were analyzed in an area of 250,000 µm² for each tissue category. Results The initially very high cellular density in the early embryonic bovine disc (11,431 cells/mm²) steadily decreases during gestation, growth and maturation to about 71 cell/mm² in the fully grown cattle. Interestingly, in human degenerative discs, a new increase in this figure could be noted (184 cells/mm). The IVD chondrocytes appear to be predominantly present as single cells. Especially in the time after birth, string-formations represent up to 32% of all cells in the anulus fibrosus, although single cells are the predominant spatial pattern (>50%) over the entire time. With increasing degeneration, the relative proportion of single cells in human IVDs continuously decreases (12%). At the same time, the share of cells organized in clusters increases (70%). Conclusion Similar to articular cartilage, spatial chondrocyte organization appears to be a strong indicator for local tissue degeneration in the IVD. Clinical Significance In the future these findings may be important for the detection and therapy of IVD degeneration in early stages.

Biomechanical properties of cells and tissues not only regulate their shape and function but are also crucial for maintaining their vitality. Changes in elasticity can propagate or trigger the onset of major diseases like cancer or osteoarthritis (OA). Atomic force microscopy (AFM) has emerged as a strong tool to qualitatively and quantitatively characterize the biomechanical properties of specific biological target structures on a microscopic scale, measuring forces in a range from as small as the piconewton to the micronewton. Biomechanical properties are of special importance in musculoskeletal tissues, which are subjected to high levels of strain. OA as a degenerative disease of the cartilage results in the disruption of the pericellular matrix (PCM) and the spatial rearrangement of the chondrocytes embedded in their extracellular matrix (ECM). Disruption in PCM and ECM has been associated with changes in the biomechanical properties of cartilage. In the present study we used AFM to quantify these changes in relation to the specific spatial pattern changes of the chondrocytes. With each pattern change, significant changes in elasticity were observed for both the PCM and ECM. Measuring the local elasticity thus allows for drawing direct conclusions about the degree of local tissue degeneration in OA.

Targeted infiltrations to the lumbar spine are used to identify the correct scope for surgery in patients with chronic lumbar back pain (CLBP) and multi-segmental pathologies, where radiologic imaging and clinical presentation do not match. Conclusions from that method have so far been based on individual statements of pain relief. The main principle for the infiltrations is the assumption that by locally administering an analgesic agent to possible surgical target areas, the effect of surgery can be temporarily simulated. The aim was to investigate the use of rasterstereographic posture measurements to substantiate reported pain reduction after infiltrations.In this case-control study (Level II), rasterstereography was performed on 57 patients and 28 reference subjects to evaluate changes in posture during 1 week of injections under fluoroscopic guidance and correlated with changes in the Numeric Pain Rating Scale (NRS). Statistical analysis was performed with SPSS (The CLBP patients' trunk inclination (median 6°) and absolute lateral tilt were significantly increased (p .01 each) compared to the reference group. No significant difference was observed for trunk length, kyphotic/lordotic angle, or lateral deviation. During infiltration, no significant difference in posture could be observed. A subgroup analysis of patients reporting the highest pain improvement indicated no significant difference. No correlation was observed with pain improvement reported by the patients during injections. Subsequent rasterstereography does not seem to be able to verify results of injections in the diagnostics of lumbar spine pathologies, as patients' reported pain relief does not correlate with a relevant alteration in posture. The short-term effect of the targeted infiltrations may not suffice to change false posture being developed over years.Gezielte Infiltrationen der Lendenwirbelsäule im Rahmen einer Stufendiagnostik werden verwendet, um den Operationsumfang bei Patienten mit chronischen Rückenschmerzen (CLBP) und multisegmentalen Pathologien zu ermitteln, bei denen radiologische Bildgebung und klinische Darstellung nicht vollends übereinstimmen. Schlussfolgerungen aus dieser Methode basierten bisher auf individuellen Aussagen zur Schmerzlinderung. Das Hauptprinzip ist hierbei die Annahme, dass durch die lokale Verabreichung eines Analgetikums, an mögliche chirurgische Zielbereiche, der Effekt einer Operation vorübergehend simuliert werden kann. Studienziel war es, die rasterstereografische Haltungsmessungen zu untersuchen, um die patientenseitig angegebene Schmerzreduktion zu objektivieren.In dieser Fall-Kontroll-Studie wurde bei 57 Patienten und 28 Referenzpersonen eine Rasterstereografie durchgeführt, um Veränderungen der Körperhaltung während einer stationären Stufendiagnostik über den Zeitraum einer Woche zu bewerten und mit Veränderungen der numerischen Schmerzbewertungsskala (NRS) zu korrelieren. Die statistische Analyse wurde mit SPSS (α = 0,05, zweiseitig) durchgeführt und in Form von Box-, Scatter- und Bland-Altman-Diagrammen dargestellt.Die Rumpfneigung der CLBP-Patienten (Median 6°) und die absolute Seitenneigung waren im Vergleich zur Referenzgruppe signifikant erhöht (jeweils p 0,01). Für Rumpflänge, kyphotischen/lordotischen Winkel oder laterale Abweichung wurde kein signifikanter Unterschied beobachtet. Während der Infiltration konnten keine signifikanten Haltungsunterschiede festgestellt werden. Eine Subgruppenanalyse der Patienten mit der höchsten Schmerzverbesserung ergab keinen signifikanten Unterschied. Es wurde keine Korrelation mit der von den Patienten während der Injektionen berichteten Schmerzverbesserung beobachtet.Die Rasterstereographie scheint demnach nicht geeignet zu sein, die Ergebnisse im Rahmen der Stufendiagnostik zu objektivieren, da die berichtete Schmerzlinderung der Patienten nicht mit relevanten Änderungen der Körperhaltung korreliert. Der kurzfristige Effekt der gezielten Infiltration reicht möglicherweise nicht aus, um über Jahre hinweg entwickelte Fehlhaltungen zu ändern.

The rise in the number of patients with lumbar back pain has led to an increase in the number of spinal surgeries. To avoid unfavorable outcomes, high accuracy and reliability of indication for surgery are essential. This requires critical evaluation of postoperative outcomes with its two key dimensions pain and function. While imaging findings give details about the technical dimension of the intervention, they are prone to high inter-/intra-observer variability, with limited relation to functional outcomes. Pain improvement can be directly asked from patients or documented by questionnaires. There is abundant literature on postoperative function based on questionnaires, but quantifiable data such as gait or posture analysis are scarce. Highprecision measurement tools are available and easy to implement in a clinician's work routine.This study evaluates whether lumbar fusion surgery changes gait and postural variables and how these changes are related to patients' descriptions of alterations in their levels of pain.Back profiles and gait analyses were measured by video rasterstereography and treadmill gait analysis. Measurements were recorded before surgery, at discharge, after 3 months in a longitudinal (n = 30), and after 12 months in a cross-sectional group (n = 29). A reference group was formed (n = 28). The improvement on the Numeric Pain Rating Scale was documented and compared with changes in gait and posture.A significant reduction in kyphotic (52-43°, p = 0.014) and lordotic (28-11°, p 0.001) angles was observed. The values again increased after 3 months, with a significant reduction in cadence (98-91 steps/min, p = 0.006). While improvements in pain were also obtained by surgery (p 0.001), no clear correlation could be detected between 3-month alleviation in pain and changes in kyphotic/lordotic angle or cadence.Although both methods offer high-precision measurement, changes in gait and posture were not related with the patients' reported pain relief after lumbar fusion surgery.

Background Spinal surgeries have strongly increased in number over the past decade. The question of when it is safe to resume driving is thereby one the most frequently asked questions that patients ask of their treating physician. Objective The aim of this study was to assess braking performance before and after spine surgery. Methods Reaction time, foot transfer time (together brake response time [BRT]), and brake force (BF) were evaluated in a drive simulator. A longitudinal patient cohort (n= 27) was tested preoperatively and at the first follow-up. A cross-sectional cohort (n= 27) was tested at > 1 year postoperatively. The values from these groups were compared with a healthy age-matched control group of 24 volunteers. Results No significant improvement in BRT was seen in lumbar fusion three months postoperatively (p= 0.597); BF was even weaker than it was preoperatively (p= 0.044). In comparison to the control group (median BRT 479 ms), preoperative BRT was already impaired in lumbar fusion patients (median 560 ms), representing an increased braking distance of 2.25 m at 100 km/h. Conclusion Although most patients performed adequately, about one third presented critical braking performance. Risk factors for impaired braking may include scheduled multisegmental fusion surgery, female sex, and pain.

The discussion as to whether or not to use closed suction drainage (CSD) after total knee arthroplasty (TKA) is still ongoing. A multitude of surgical techniques makes comparison between studies difficult. The aim of the present study was to investigate the benefit of CSD versus nondrainage following primary TKA when operating after exsanguination (by means of a rubber Esmarch bandage) with a tourniquet and without any form of hemostasis. A prospective randomized trial was performed with a homogeneous sample of 36 patients with strict inclusion and exclusion criteria. Patients were evaluated preoperatively, on a daily basis during their hospital stay, and at 6 weeks, 3 months, 6 months, and 1 year postoperatively. The use of CSD led to a significantly stronger drop in hemoglobin levels by approximately 1 g/dL (p = 0.012). Knee circumference, wound secretion, wound healing, and postoperative range of motion did not show significant differences. All discharge criteria were met in both groups by day 9. Interestingly, patients without CSD reported higher pain levels during the entire postoperative inpatient stay and also at the 6-week follow-up (p = 0.012). These differences could not be observed in longer follow-up. The use of CSD after primary TKA in this study did not lead to indispensable advantages but did lead to increased postoperative blood loss. When evaluating the advantages and disadvantages of the use of CSD after TKA from the data in the literature, special attention must be paid to the operating technique, as it has a strong impact on the results obtained.

Zusammenfassung Hintergrund Die Indikationsstellung zur Operation bezieht ihre Legitimation zum Eingriff in die körperliche Unversehrtheit eines Patienten im Wesentlichen aus dem zu erwartenden Behandlungserfolg. Um die Wahrscheinlichkeit und das Ausmaß eines Operationserfolgs bereits präoperativ abzuschätzen, muss der Chirurg in kurzer Zeit eine Fülle an Parametern evaluieren, die über die rein technische Dimension des Eingriffs hinausgehen. Trotz höchster Versorgungsstandards zeigt die postoperative patientenseitige Zufriedenheit eine immense Streubreite bei für den Arzt technisch zufriedenstellendem Ergebnis. Ziel der folgenden Studie war es, zu untersuchen, mit welcher Präzision individuelle postoperative Zufriedenheit und Schmerzangabe von Patienten bei elektiven muskuloskeletalen Eingriffen vorhergesagt werden können, und ob diese Vorhersagepräzision abhängig ist vom ärztlichen Ausbildungsstand. Zudem sollte evaluiert werden, ob bei einem hoch standardisierten Eingriff, wie dem endoprothetischen Gelenkersatz, eine höhere Präzision möglich ist als im restlichen Operationsgut. Material und Methoden Die Ärzte der Klinik gaben präoperativ eine Einschätzung über die erwartete Zufriedenheit (Skala 0 – 10) und Schmerzstärke (NRS) der Patienten für den Zeitpunkt 6 Monate postoperativ ab. Zu diesem Zeitpunkt erfolgte dann die Erhebung dieser Parameter bei den Patienten. Die ärztliche Beurteilung erfolgte im Rahmen der präoperativen Visite am Vortag zur Operation. Unterschiedlich erfahrene Kollegen konnten so zeitgleich dieselben Patienten einschätzen. Verglichen wurden die Angaben von Ober- und Fachärzten mit denen der Assistenzärzte in Gegenüberstellung zu den Angaben der Patienten. Ergebnisse Insgesamt wurden 194 Einschätzungen ausgewertet. Durch die Operation konnte eine deutliche Schmerzbesserung erzielt werden (Median NRS prä-OP 6,25, post-OP 2,5, p Schlussfolgerung Auch wenn sich die ärztliche Einschätzung insgesamt mit den Patientenangaben annähernd deckt, so sind auf den Einzelfall bezogen starke Abweichungen zu verzeichnen, die auch in einem hoch standardisierten Kollektiv, wie dem der primären Endoprothetik, bestehen. Eine Zunahme der Einschätzungsqualität mit fortschreitendem ärztlichem Ausbildungsstand war nicht festzustellen. Hier lassen die Daten die Vermutung zu, dass über die technische Dimension hinaus andere Faktoren ebenfalls von entscheidender Bedeutung sind, wie z. B. die präoperative Erwartungshaltung des Patienten. Anspruch eines jeden Operateurs muss es daher sein, eine realistische Erwartung an die Operation mit dem Patienten gemeinsam zu entwickeln und sich dabei der eigenen Grenzen bez. der Vorhersagepräzision des Erfolgs bewusst zu sein.

Focal cartilage defects can be treated by osteochondral autologous transplantation (OAT). High congruence of the graft with the surrounding cartilage structure is essential for a good clinical outcome, but can not always be achieved. We recently established a method to measure dissipated energy (DE) as a friction parameter in knee joints. We now investigated how autograft harvesting and implant positioning affect the DE during knee motion. Six sheep knee joints were cyclically motioned under 400 N axial load. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. Several experimental conditions were tested: first, the DE was measured after approach had been performed ("native"). Subsequently, a cylinder was removed from the medial femur condyles and a donor cylinder was inserted from an unloaded site in four different transplant positions: even, 1 mm deeper, 1 mm higher, and flush without cartilage (defect). No significant changes in friction were observed between the native knee and an even or deep OAT positioning. We, however, found a small but significant increase in DE between the "native" and "1 mm high" formations (ΔDE compared with native = 14 mJ/cycle; P = .004 after data normalization) and a large increase in defect situation (ΔDE compared with native = 119 mJ/cycle; P = .001). Considering the long-term therapeutic aim that is pursued when performing OAT, elevated graft positioning should clearly be avoided. From a biomechanical point of view, donor site morbidity after cylinder harvest can be neglected.

This protocol provides guidance on how to perform high resolution video rasterstereography and treadmill gait analysis on patients after lumbar fusion surgery to obtain results about altered variables of gait and posture. These observed changes can then be correlated with the patient-reported outcome measure of pain relief. The rasterstereographic device projects lines of parallel light onto the surface of the tested subject's back. The deformation of these lines is recognized by the device. From these data, a special software then generates a 3-D profile based on the principle of triangulation. With an inaccuracy of only 0.2 mm it can measure changes in posture at very high precision. Gait and stance parameters are recorded using a treadmill equipped with an electric sensor mat that contains 10,200 miniature force sensors in the registering zone under the belt. Initial walking speed on the treadmill is 0.5 km/h. Speed is then gradually increased by increments of 0.1 km/h until each subject reaches his or her individual maximum well tolerable walking speed. At this speed, parameters are recorded during a 20 s measurement interval. Subjects are tested barefoot and without holding a handrail. Among various other parameters, stride width, step length, stance phase and foot rotation are measured. Both methods used reportedly have a high intra- and inter-observer reliability. The advantage of these highly accurate techniques is that they offer an objective and very detailed perspective on changes in the patient's posture and gait. Due to the amount of data generated, these techniques are, however, not so much suitable for everyday routine use, but rather interesting to scientifically evaluate long term alterations in posture and gait in patients like for example after lumbar fusion surgery.

Contaminated suture material plays an important role in the physiopathology of surgical site infections. Recently, suture material has been developed characterized by barbs projecting from a monofilament base. Claimed advantages for barbed sutures are a shortened wound closure time and reduced maximum wound tension. It has also been suggested that these sutures would be advantageous microbiologically. The aim of this study was to test the microbiological characteristics of the barbed Quill in comparison to the monofilament Ethilon II and the braided sutures Vicryl and triclosan-coated Vicryl Plus. In our study, sutures were cultivated on color-change agar with Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa and the halo size was measured. In a second study arm with longer cultivation bacterial growth was followed by antibiotic treatment. Ethilon II and Quill showed good comparable results, whereas large halos were found around Vicryl. Vicryl Plus results depended on triclosan sensitivity. After longer bacterial cultivation and antibiotic treatment, halos were up to 3.6 times smaller on Quill than on Vicryl (p

Patients with chronic lumbar back pain (CLBP) often present with an altered gait profile, which is a crucial element of good functioning in everyday life. In patients with multisegmental spinal pathologies and incongruity between radiologic imaging and clinical presentation, inpatient gradual diagnostics (IGD) is performed to determine the precise origin of the disabling pain. The underlying principle of IGD is the assumption that by locally administering an analgesic and anti-inflammatory agent to possible surgical target areas, the surgical effect can be temporarily simulated. The conclusions drawn from IGD are, however, mostly based on the patients' subjective feedback about pain relief.The aim of this study was to evaluate whether reported pain relief during IGD can be objectified by gait analysis. We hypothesized that patients with greater pain relief during IGD would show greater improvement in their pathologic gait and stance.Treadmill gait and stance analyses were prospectively performed on CLBP patients before and after a one-week IGD. Self-report measures included the numeric pain rating scale (NRS) and the Oswestry Disability Index (ODI).Compared with a reference group (n = 28), IGD patients (n = 57) at admission showed reduced velocity, cadence, step length, and swing phase (p .01 each). Their stance phase was increased by 5% of the gait cycle, and a more asymmetrical total load distribution during stance was observed. No difference was seen in stride width or foot rotation. While many patients reported good pain relief during IGD, no correlation was observed between subjective improvement and treadmill measures. We can thus confirm a pathologic gait profile in patients with CLBP. Based on our findings, gait analysis would not yet seem suitable to objectify IGD results. The short time interval between admission and discharge may not suffice to change a pathological gait that has developed over years.

Objective The objective of this study was to investigate whether total knee arthroplasty (TKA) impairs the ability to perform an emergency stop. Design An automatic transmission brake simulator was developed to evaluate total brake response time. A prospective repeated-measures design was used. Forty patients (20 left/20 right) were measured 8 days and 6, 12, and 52 wks after surgery. Results Eight days postoperative total brake response time increased significantly by 30% in right TKA and insignificantly by 2% in left TKA. Brake force significantly decreased by 35% in right TKA and by 25% in left TKA during this period. Baseline values were reached at week 12 in right TKA; the impairment of outcome measures, however, was no longer significant at week 6 compared with preoperative values. Total brake response time and brake force in left TKA fell below baseline values at weeks 6 and 12. Brake force in left TKA was the only outcome measure significantly impaired 8 days postoperatively. Conclusion This study highlights that categorical statements cannot be provided. This study's findings on automatic transmission driving suggest that right TKA patients may resume driving 6 wks postoperatively. Fitness to drive in left TKA is not fully recovered 8 days postoperatively. If testing is not available, patients should refrain from driving until they return from rehabilitation.

Objective: While several radiographic parameters have been established to describe the geometry and pathology of the hip, their reference values and clinical significance remain a matter of dispute. The present study tests the hypothesis that age has a relevant impact on radiographic hip parameters. Method: Pelvic antero-posterior views were measured for CE angle, Sharp’s angle, acetabular depth-to-width ratio, femoral head extrusion index, roof obliquity, caput-collum-diaphyseal (CCD) angle, and Murray’s femoral head ratio, and the values obtained were correlated with age. Results: Significant weak and moderate linear correlations (all Ps