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BACKGROUND: Severe acetabular bone loss in revision total hip arthroplasty (RTHA), both with or without pelvic discontinuity, remains a great challenge in orthopaedic surgery. OBJECTIVE: The aim of this study was to evaluate risk factors for failure of custom-made acetabular implants in RTHA. METHODS: Seventy patients with severe acetabular bone loss (Paprosky Type III) and pelvic discontinuity, who required RTHA, were included in our study. All prostheses were constructed based on a thin-layer computed-tomography (CT) scan of the pelvis. The treatment was considered unsuccessful in the event of periprosthetic joint infection (PJI) or aseptic loosening (AL) with need for explantation of the custom-made acetabular implant. RESULTS: The average follow-up was 41.9 ± 34.8 months (range 1.5–120). Implant survival at last follow-up was 75.7% (53 of 70). Explantation was necessary in 17 cases (15 PJI; 2 AL). Previous PJI as reason for RTHA (p= 0.025; OR 3.56 (95% CI: 1.14; 11.21)), additional revision of femoral components (p= 0.003; OR 8.4 (95% CI: 1.75; 40.42)), rheumatoid disease (p= 0.039; OR 3.43 (95% CI: 1.01; 11.40)), elevated preoperative CRP > 15.2 mg/l (p= 0.015; AUC: 0.7) and preoperative haemoglobin < 10.05 (p= 0.022; AUC: 0.69) were statistically significant risk factors associated with treatment failure. Age and BMI were not statistically significant contributing to implant failure. CONCLUSION: Risk factors for treatment failure were a previous PJI, additional revision of femoral component, rheumatoid disease, elevated preoperative CRP and low preoperative haemoglobin. Awareness of these risk factors will help to improve future treatment standards.

The key element for differentiation between normal anatomical variants and pathological deformities is the prior definition of normal ranges for anthropometric parameters of acetabulum according to each age group. Aim of the present study is to analyze the development of the acetabulum in children/adolescents by accurate anthropometric measurements using 3D-CT scans and determine the variations occurring depending on age, gender and/or side. This retrospective observational study included 85 patients (170 hips) under 15 years of age (0-15) undergoing 1.5mm CT scanning for non-hip related reasons. The measurements were performed by 2 board-certified orthopaedic surgeons. Each year of life represented an age group forming a total of 16 groups. Median number of patients per age group was 12 (range 4-16). The anthropometric parameters included acetabular volume, inclination, version, depth (coronal and axial), width (coronal and axial), Tönnis angle as well as anterior and posterior acetabular sector angles. Mean values, range, standard deviation, p-values, intra- and interrater reliability were calculated. All measurement values correlated significantly with age. Statistically, there was no side or gender related difference. Rapid growth phases were observed at the age of 11-12. The inter- and intrarater reliability was high (range ICC 0.8-0.99, Cronbach alpha 0.86-0.99, Bland-Altman good agreement). The present data provides age- and gender-related normative values as well as growth phases describing acetabular morphology. It should help paediatricians as well as paediatric and orthopaedic surgeons as a tool for early diagnosis of deformity and guidance for possible procedures.

Normal anatomical variants and pathological deformities of the pediatric hip can only be differentiated after a prior definition of normal ranges for anthropometric parameters with increasing age. Aim of the present study was to provide reliable reference values of the pediatric hip morphometry, using computed tomography (CT)-based rotation-corrected summation images of the pelvis that simulate the widely available plain radiograph-based measurements, but offer the higher precision of the CT technique. This retrospective study included 85 patients (170 hips) under 15 years of age (0-15). The measured anthropometric parameters included femur head extrusion index, lateral center-edge angle, acetabular inclination, Tönnis angle, and femoral neck-shaft angle. Mean values, range, SD, P values, intra-rater, and inter-rater reliability were calculated. All measurements correlated with age. None of the measurements correlated with gender or side. Rapid growth phases were noted in all measurements at the age of 12 (14 in males and 11 in females). The inter-rater and intra-rater reliability was high (range inter/intraclass correlation coefficient 0.926-0.998 Cronbach's alpha 0.986-0.998). The present work provides age- and gender-related normative values of the classically used hip measurements as well as growth phases describing pediatric hip morphology in a broad age range. A discrepancy was noted between the values measured in the current study and the classical X-ray-based reference values in the literature especially for the Tönnis angle and LCEA values. This suggests that the rotation and inclination correction in the CT-based techniques might have the advantage of compensating for a possible overestimation in the conventional X-ray-based methods.

PurposeDefining normal anthropometric ranges of proximal femur and femoral head for each age group in children/adolescents is a necessity when differentiating normal anatomical variants from pathological deformities. Aim of this study is to define a set of normal anthropometric parameters based on 3D-CT measurements in normal asymptomatic children/adolescents and analyse the variations arising depending on age, side, and/or gender.MethodsMorphology of the proximal femur was retrospectively assessed in 170 hips (85 children, ResultsCFHV, LCEA, FHD and AOS/POS increased with age and FHEI, CAA, and FNSA decreased with age. None of the measurements correlated with the side. AOS showed a poor correlation with gender. Rapid growth phases were observed at the age of 1, 7 and 11. The inter- and intra-rater reliability was high (range ICC 0.8–0.99 Cronbach alpha 0.86–0.99).ConclusionThis data delivers a description of growth phases as well as gender and age-correlated reference values of the proximal femoral morphology that could be used by paediatricians and orthopaedic/paediatric surgeons to early diagnose proximal femur deformities and provide guidance in the planning of possible operations.

Singleton-Merten syndrome (SMS) is a type I interferonopathy. In this report, we disclose the first-to the best of our knowledge-direct association of SMS with femoral head necrosis (FHN). The following case report presents the condition of a 38-year-old male suffering from SMS with FHN, characterized by acute symptoms and rapid disease progression. As per the recommendations of the Association Research Circulation Osseous (ARCO) and the S3-guidelines, we successfully treated the FHN with core decompression. Our histological results correlate with the changes described in medical literature in patients with SMS and MDA5-knockout in vivo experiments such as osteopenia, widened medullary cavity, and thin cortical bone. Moreover, the conducted immunohistochemistry shows strong CD56 positivity of the osteoblasts and osteocytes, as well as significant CD68 and CD163 positivity of the middle-sized osteoclasts. Collectively, these findings suggest an underlying syndrome in the FHN. A six-month post-operative follow-up revealed complete recovery with the absence of the initial symptoms and ability to resume normal daily activities. Taken together, our findings suggest that SMS is an additional cause of FHN in young adults. Early detection and adequate treatment using well-established joint-preserving techniques demonstrate a favorable improvement of the patient's clinical condition.

Primary care hospitals and regional trauma centers play an essential role in the treatment of hip fractures.This study investigated the relationship between patient-related parameters and in-hospital mortality as well as complications of hip fractures at a regional trauma center.In a retrospective study, data were collected from all patients 60 years admitted over 2 years to a regional trauma center with a hip fracture. Patient-related parameters included age, sex, fracture location, method of surgical treatment, time of surgery, duration of surgery, length of inpatient stay, blood transfusion, complications, comorbidities, use of anticoagulant medication and need for postoperative intensive care treatment. The relationship between these parameters and hospital mortality as well as complications was investigated.Data were collected from 360 patients undergoing 335 surgeries (f:m 225:110) with a mean age of 83 ± 8 years. The total in-hospital mortality rate was 7.76% (n = 26). Factors increasing in-hospital mortality included: age 85 years (odds ratio [OR] 5.126; 95% confidence interval [CI] 0.665-39.498; p = 0.1167); male sex (OR 1.85 95%-CI [0.82-4.14]; p = 0.0555); time of surgery 24 h (OR 1.896 95%-CI [0.661-5.441]; p = 0.2341); ≥ 3 comorbidities (OR 10.61 95%-CI [3.681-27.501]; p 0.0001); intake of anticoagulants (OR 6.19 95%-CI [2.69-14.24]; p 0.0001) and postoperative intensive care (OR 5.9 95%-CI [2.56-13.76]; p 0.0001).In the present study a statistically significant influence of the number of comorbidities or Charlson comorbidity index, the intake of anticoagulant drugs and need for postoperative intensive care treatment on the in-hospital mortality of patients with proximal femoral fractures in a regional trauma center was found.HINTERGRUND: Krankenhäuser der Grund- und Regelversorgung bzw. regionale Traumazentren spielen eine essenzielle Rolle in der Versorgung hüftgelenknaher Frakturen. ZIEL: Die vorliegende Arbeit untersucht den Zusammenhang zwischen patientenbezogenen Parametern und der Klinikmortalität sowie dem Auftreten von Komplikationen bei solchen Frakturen an einem regionalen Traumazentrum.Im Rahmen einer retrospektiven Studie wurden die Daten von allen Patienten, die über 2 Jahre an einem regionalen Traumazentrum mit einer hüftgelenknahen Fraktur aufgenommen wurden, erfasst. Eingeschlossen wurden nur Patienten älter als 60 Jahre. Die patientenbezogenen Parameter umfassten Alter, Geschlecht, Frakturlokalisation, Methode der operativen Versorgung, Operationszeitpunkt, Dauer der Operation und des stationären Aufenthalts, Bluttransfusion, Komplikationen, Komorbiditäten, Einnahme von Antikoagulanzien und Notwendigkeit einer postoperativen intensivmedizinischen Behandlung. Der Zusammenhang zwischen diesen Parametern und der Klinikmortalität sowie dem Auftreten von Komplikationen wurde untersucht.Daten von 360 Patienten mit 335 Operationen (w:m 225:110) mit einem Alter von 83 ±8 Jahren wurden erfasst. Die Klinikmortalität lag bei 7,76 % (n = 26) und erhöhte sich bei Alter 85 Jahren (Odds Ratio [OR] 5,126; 95%-Konfidenzintervall [95 %-KI] 0,665–39,498; p = 0,1167), männlichem Geschlecht (OR 1,85 95%-KI [0,82–4,14]; p = 0,0555), Zeitpunkt der Operation 24 h (OR 1,896 95%-KI [0,661–5,441]; p = 0,2341), ≥ 3 Vorerkrankungen (OR 10,61 95%-KI [3,681–27,501]; p 0,0001), Einnahme von Antikoagulanzien (OR 6,19 95%-KI [2,69–14,24]; p 0,0001) und notwendiger postoperativer intensivmedizinischer Behandlung (OR 5,9 95%-KI [2,56–13,76]; p 0,0001).In der vorliegenden Studie fanden sich statistisch signifikante Einflüsse der Anzahl der Komorbiditäten, der Einnahme von Antikoagulanzien sowie der intensivmedizinischen Behandlung auf die Klinikmortalität bei Patienten mit hüftgelenknahen Frakturen an einem regionalen Traumazentrum.

ZusammenfassungDas undifferenzierte pleomorphe Sarkom („undifferentiated pleomorphic sarcoma“ [UPS]) gehört zur Gruppe der Weichteilsarkome und macht fast 10 % aller Weichteilsarkome aus. Der Fall eines 49-jährigen Patienten wird vorgestellt, bei dem die kompartmentorientierte Resektion eines primären UPS im linken Musculus gluteus maximus mit adjuvanter Radiotherapie (60 Gy) durchgeführt wurde. Im Rahmen der Tumornachsorge (3 Jahre später) wurde eine lokoregionäre Metastase an einer ungewöhnlichen Lokalisation im M. quadratus femoris festgestellt, welche mittels einer In-toto-Resektion mit intraoperativer Radiotherapie (10 Gy) behandelt wurde. Der intra- und postoperative Verlauf gestalten sich komplikationslos ohne neurologische Defizite. Im Rahmen der Nachtuntersuchung 6 Monate postoperativ war der Patient tumor- und beschwerdefrei.

BACKGROUND: To date only scanty data exist regarding the effect of failed debridement, antibiotics, irrigation and retention of the prostheses (DAIR) and negative pressure wound therapy (NPWT) on the outcome of a subsequent exchange arthroplasty. OBJECTIVE: The objective of this study was to determine the success rate of a two- or multi-stage procedure after initial failed DAIR/NPWT in patients with an acute periprosthetic joint infection (PJI) and to evaluate the influence of possible risk factors for treatment failure. METHODS: Nineteen consecutive patients with a persisting PJI and ongoing NPWT after treatment of an acute PJI with DAIR of the hip or knee joint from October 2010 to June 2017 were included. All patients were treated according to a structured treatment algorithm after referral to our hospital. The endpoint was a successful reimplantation with absence of signs of infection two years after replantation (“replantation group”) or treatment failure (“treatment failure group”) in terms of a permanent girdlestone arthroplasty, fistula, amputation or death. A risk factor analysis was performed between the two groups. RESULTS: Explantation was performed in 15 cases, amputation in one case, and DAIR/establishment of a fistula in three cases. The treatment success rate after reimplantation in terms of “definitively free of infection” two years after surgery according to Laffer was 36.85% (seven out of 19 patients). Statistical analysis revealed the number of surgeries until wound consolidation (p= 0.007), number of detected bacterial strains (p= 0.041), a polymicrobial PJI (p= 0.041) and detection of a difficult-to-treat organism (p= 0.005) as factors associated with treatment failure. After failed DAIR/NPWT we could detect a significant higher number of different bacterial strains (p= 0.001). CONCLUSIONS: The treatment success rate after failed DAIR and NPWT with 36% is low and associated with a high treatment failure rate (permanent girdlestone arthroplasty, fistula or amputation, death). Thus, the definition of risk factors is crucial. We found that the number of revisions until wound consolidation, a polymicrobial PJI and detection of a difficult-to-treat organisms were risk factors for treatment failure. Furthermore, after failed DAIR/NPWT we could detect a significant higher number of different bacterial strains, with a possible adverse effect on a consecutive exchange.

Verwendung von modularen achsgefuhrten Revisionsimplantaten zur Wiederherstellung einer stabilen Kniegelenkkinematik in der Revisionsendoprothetik. Revisionsimplantat bei Knochendefekten Grad I) oder multidirektionaler Instabilitat. Persistierender Gelenkinfekt, genereller Infekt (Pneumonie, Harnwegsinfekt [HWI]), fehlende/nicht ausreichende Knochenverankerungsmoglichkeit femoral und tibial (AORI >IIb), destruierter, nichtrekonstruierbarer Streckapparat. Standardzugang uber bestehende Hautnarbe, Arthrotomie, Entfernung Zementspacer, wenn notwendig, und Entnahme multipler Gewebeproben; Praparation Femur first. Beginn mit Reibahlen aufsteigender Durchmesser bis zum kortikalen Kontakt. Anschliesend wird ein Referenzschaft mit einer Gelenklinienplatte so verankert, dass die Gelenklinie an der gewunschten Position zu liegen kommt. Referenzierung der Rotation und Gelenklinienhohe mit dementsprechender Entscheidung zur Verwendung von Augmenten. Femorale Osteotomie nach Ausrichtung des Schnittblockes 5‑in‑1. Nach Entfernung der osteotomierten femoralen Flachen erfolgen die Boxpraparation und anschliesend die Probeimplantation. Tibiale Schaftpraparation analog der femoralen Praparation. Anschliesend erfolgt die Verankerung des Referenzschaftes mit der tibialen Gelenklinienplatte entsprechend der gewunschten Position. Montage der tibialen Sagefuhrung und Kontrolle der Resektate; ggf. mit der Notwendigkeit zur Verwendung von Augmentaten. Durchfuhrung der Osteotomie und Entfernen der Resektate. Finale Praparation der tibialen Flache und Einschlagen der Probeprothese. Durchbewegen des Gelenkes; bei klinisch und rontgenradiologisch regelhaftem Befund und Stellung Entfernung der Probeimplantate und Implantation der definitiven Prothese. Vollbelastung; regelmasige Wundkontrolle und steriler Wundverband; Einschrankung des Flexionsgrades nur bei geschwachtem Streckapparat. Im Zeitraum von 03/2011 bis 05/2018 wurden an den Kliniken der Autoren insgesamt 48 Patienten mit einem modularen Knierevisionssystem (Typ BPK‑S, Fa. Brehm, Weisendorf, Deutschland) versorgt. In 30 Fallen erfolgte die Implantation eine „Rotating-hinge“, in 18 Fallen eine „semiconstrained“ Variante. Das mittlere Follow-up lag bei 24 Monaten. Indikationen: konsolidierte Infektion nach Prothesenausbau im zweizeitigen Intervall (n = 22), aseptische Lockerung (n = 11), Instabilitat (n = 11), periprothetische Fraktur (n = 3), Zementallergie (n = 1); 80 % der Patienten zeigten gute klinische und radiologische Ergebnisse. Insgesamt wurden 11 Re-Revisionen durchgefuhrt (5 aseptische Ursachen [jeweils 1 Luxation, periprothetische Fraktur, symptomatische Retropatellararthrose, Schmerzen und Zementallergie], 6 periprothetische Infekte [davon 4 Re-Infekte]). Alle Patienten wurden mit einem zweizeitigen Komplettwechsel behandelt, wobei in 2 Fallen schlieslich eine Arthrodese durchgefuhrt werden musste. Die Uberlebensrate im 2‑Jahres-Follow-up betrug 77 %.

Background Periprosthetic acetabular fractures are an increasing severe complication in revision arthroplasty. A differentiation is made between periprosthetic acetabular fractures (acute/traumatic fractures) and insufficiency fractures (chronic fractures). Objective This article introduces a novel treatment algorithm that provides assistance in therapeutic decision making for implant selection and the anchoring philosophy based on diagnostic decision criteria and the relevant load-bearing osseous structures, taking the defect situation into account. Material and methods The article provides an overview of original and review articles. Results The essential criteria for decisions in treatment planning are based on the stability of the primary cup, the load-bearing ability of the main anatomical structures and the resulting defect situation. For insufficiency fractures the reason for the revision and therefore the exclusion of periprosthetic joint infections (PJI) must additionally be considered. In the case of proven PJI a two-stage or multistage prosthesis exchange must be carried out. Based on the extent of apparent bony defects and pelvic discontinuity, the spectrum of treatment options ranges up to implantation of individual patient custom-made acetabular components. Discussion/conclusion This overview introduces a new treatment algorithm that provides assistance in decision making for traumatic periprosthetic acetabular fractures and insufficiency fractures. It also provides decision criteria for selection of implants and the surgical approach. Due to the complexity of revision arthroplasty often requiring specialized expertise in trauma and orthopedic surgery and experienced revision surgeons, the operative treatment of periprosthetic acetabular fractures should only be carried out in specialized orthopedic and trauma surgery centers with appropriate experience.

Rifampin is one of the most important biofilm-active antibiotics in the treatment of periprosthetic joint infection (PJI), and antibiotic regimens not involving rifampin were shown to have higher failure rates. Therefore, an emerging rifampin resistance can have a devastating effect on the outcome of PJI. The aim of this study was to compare the incidence of rifampin resistance between two groups of patients with a PJI treated with antibiotic regimens involving either immediate or delayed additional rifampin administration and to evaluate the effect of this resistance on the outcome. In this retrospective analysis of routinely collected data, all patients who presented with an acute/chronic PJI between 2018 and 2020 were recorded in the context of a single-center comparative cohort study. Two groups were formed: Group 1 included 25 patients with a PJI presenting in 2018–2019. These patients received additional rifampin only after pathogen detection in the intraoperative specimens. Group 2 included 37 patients presenting in 2019–2020. These patients were treated directly postoperatively with an empiric antibiotic therapy including rifampin. In all, 62 patients (32 females) with a mean age of 68 years and 322 operations were included. We found a rifampin-resistant organism in 16% of cases. Rifampin resistance increased significantly from 12% in Group 1 to 19% in Group 2 (p &lt, 0.05). The treatment failure rate was 16% in Group 1 and 16.2% in Group 2 (p = 0.83). The most commonly isolated rifampin-resistant pathogen was Staphylococcus epidermidis (86%) (p &lt, 0.05). The present study shows a significant association between the immediate start of rifampin after surgical revision in the treatment of PJI and the emergence of rifampin resistance, however with no significant effect on outcome.

Periprosthetic joint infection (PJI) is a serious complication after total joint arthroplasty. In the course of a PJI, superinfections with pathogens that do not match the primary infecting micro-organism may occur. To our knowledge, there are no published data on the outcome of such infections in the literature. The aim of this study was to assess the outcome of PJI with superinfections with a difficult-to-treat (DTT) pathogen. Data of 169 consecutive patients with PJI were retrospectively analyzed in this single-center study. Cases were categorized into: Group 1 including non-DTT-PJI without superinfection, Group 2 DTT-PJI without superinfection, Group 3 non-DTT-PJI with DTT superinfection, and Group 4 non-DTT-PJI with non-DTT superinfection. Group 3 comprised 24 patients and showed, after a mean follow-up of 13.5 ± 10.8 months, the worst outcome with infection resolution in 17.4% of cases (p = 0.0001), PJI-related mortality of 8.7% (p = 0.0001), mean revision rate of 6 ± 3.6 (p &lt, 0.0001), and duration of antibiotic treatment of 71.2 ± 45.2 days (p = 0.0023). PJI caused initially by a non-DTT pathogen with a superinfection with a DTT pathogen is significantly associated with the worst outcome in comparison to non-DTT-PJI, PJI caused initially by a DTT pathogen, and to non-DTT-PJI with a non-DTT superinfection.

Wiederherstellung einer schmerzfrei belastbaren Extremitat mit einem modularen Kniearthrodesesystem. Arthrodese auf Grundlage eines zementfreien modularen Revisionsschafts zur rotationsstabilen, diaphysaren Verankerung. Verlust oder Funktionsunfahigkeit des Kniestreckapparats; ausgepragte Knochen- und Weichteildestruktion nach zweizeitigem Prothesenwechsel, der die Implantation einer Knieendoprothese nicht mehr erlaubt. Ausgedehnte Osteolysen, die eine diaphysare Prothesenverankerung unmoglich machen. Kontralateral versteiftes Kniegelenk und/oder ipsilateral versteiftes Huftgelenk. Gegenseitige Oberschenkelamputation. Entfernen des ggf. noch einliegenden gelockerten Knieprothesensystems oder Spacers und – im zementierten Fall – des Knochenzements. Entfernen des intramedullaren Granulationsgewebes. Aufbohren der Markraume mit Reibahlen und flexiblen Markraumbohrwellen. Uberprufen der Beinlange und Rotation mittels Probeimplantaten. Formschlussige, zementfreie Implantation der sternformigen, modularen femoralen und tibialen Verankerungsschafte mit diaphysarem „Press-fit“. Aufsetzten und Verspannen der rotationsgerecht ausgerichteten Kopplungselemente. Mobilisation an Unterarmgehstutzen ab dem 1. postoperativen Tag. Entfernen der Redondrainagen nach 48 h. Teilbelastung mit 20 kg fur 6 Wochen postoperativ. Bei nativradiologisch unverandertem Prothesensitz nach 6 Wochen Steigerung der Belastung um wochentlich 10 kg bis zur Vollbelastung. Zwischen 2007 und 2012 untersuchten wir 27 Patienten, die mit dem Kniearthrodesesystem TITAN (KAM-TITAN) versorgt wurden. Der Nachuntersuchungszeitraum lag bei 30,9 ± 12,0 Monaten. Die mit dem Oxford Knee Score (OKS) gemessenen klinischen Ergebnisse ergaben im Mittel Werte von 39,2 ± 8,3 Punkten. Die Schmerzintensitat wurde mittels Visueller Analog Skala (VAS) bestimmt und lag bei den Patienten bei durchschnittlich 2,9 ± 1,3. Im Nachuntersuchungszeitraum lag bei 85,2 % der Patienten ein infektfreier Status vor.

Background Postoperative complications are the main consumers of technical, medical, and human resources. Especially in the field of elective joint replacement surgery, a specialized, easy-to-obtain, and cost-efficient preoperative stratification and risk-estimation model is missing. Methods With preoperatively surveyed patient parameters, we identified the most relevant parameters to predict postoperative medical complications. We devised a prospective risk model, measuring the individual probability for intermediate care unit (IMC) or intensive care unit (ICU) admission. The study includes all patients (n = 649) treated with primary or revision total knee arthroplasty in our clinic from 2008 to 2012. Results The association between general comorbidity scores and mortality risk is well known. Among different comorbidity scores, the Charlson Comorbidity Index is not only relevant for overall postoperative complications (odds ratios [OR] = 2.20) but also predictive of specific complications such as the postoperative need for blood transfusion (OR = 1.94) and unexpected adverse events (OR = 1.74). Considering adverse events, c-reactive protein and leukocyte levels are also highly relevant. Upon predicting a necessary postoperative transfer to an IMC or ICU, the preoperative hemoglobin level, the Charlson Comorbidity Index, and the Index of Coexistent Disease stood out. The latter indicates an increased rate for an IMC/ICU stay by 341% per point. Condensing the most influential predictors, the probability for postoperative IMC/ICU transfer can be calculated for each individual patient. Using the routinely assessed patient's variables, no steadier prediction is possible. Conclusion The introduced risk-estimation model offers a specialized preoperative resource-stratification method in knee joint replacement surgery. It condenses the most influential, individual risk factors to avoid clinical test redundancy and improve resource efficiency and presurgical care planning. A prospective follow-up study could help validating the risk model in clinical routine.

Periprosthetic loosening, either aseptic or induced by periprosthetic joint infection remains a major long term complication and challenge in orthopedics and trauma surgery. Sensitivity of potential loosening of the material and other causes of a painful prosthesis is essential for choosing the respective treatment option and providing the needed resources. 18F-Fluoride is a radiopharmaceutical which shows a high affinity to bone and a rapid blood clearance. The objective of this study was to assess 18F-Fluoride PET/CT´s sensitivity and specificity in diagnosing periprosthetic loosening in total hip and knee arthroplasty. We included 26 patients with 24 hip and 13 knee prostheses in our retrospective study with radiological or clinical suspicion of peri-prosthetic loosening at least one year after implantation. Results of 18F-Fluoride PET/CT imaging were compared with surgical results or clinical follow-up if surgery was not performed. On the basis of our data we found a sensitivity of 95.00 %, a specificity of 87.04 % and an accuracy of 89.19 % for 18F-Fluoride PET/CT. The results of our study show that 18F-Fluoride PET/CT is a useful and promising technique in diagnosing periprosthetic loosening of total hip and knee arthroplasties. Further investigation should focus on different uptake patterns of the isotope in periprosthetic joint infection and therefore distinguishing aseptic from septic loosening and enhancing the diagnostic value of this imaging method.

Ziel der Operation ist die Wiederherstellung einer beschwerdearmen Schulterfunktion durch Implantation eines modularen, proximalen Humerusersatzes in der Revisionsendoprothetik bei ausgepragtem segmentalem humeralem Knochenverlust. Segmentale humerale Knochendefekte in der Revisionsendoprothetik des Schultergelenks nach Tumorresektion, Trauma, pathologischen Frakturen, postinfektios oder fehlgeschlagener Osteosynthese. Lokale floride Infektionen, ausgedehnte diaphysare Knochendefekte mit ausgedunnter Kortikalis und weitem diaphysarem Markraum, die eine diaphysare Prothesenverankerung nicht erlauben. Relative Kontraindikationen: Sehr kurze Lebenserwartung (

Objectives Complex regional pain syndrome (CRPS) and associated comorbidities have been linked to a pro-inflammatory state driven by different mediators. Targeted dorsal root ganglion stimulation (DRGSTIM ) suppressed pain levels and improved functional capacity in intractable CRPS. However, clinical trials assessing the impact of DRG stimulation on the neuroimmune axis are lacking. Methods This study enrolled 24 subjects (12 refractory CRPS patients plus suitably matched healthy controls) and performed immunoassays of inflammatory mediators in saliva and serum along with score-based assessments of pain, mood, and sleep quality at baseline and after three months of selective L4-DRGSTIM . Results After three-month L4-DRGSTIM CRPS associated pain significantly decreased. In addition, disturbed sleep and mood improved post-DRGSTIM , although statistically not significant. Significantly increased serum values of pro-inflammatory markers were detected pre- and post L4-DRGSTIM for high-mobility group box 1, tumor-necrosis factor α, interleukin (IL) 6, and leptin. IL-1β was significantly elevated pre-L4 DRGSTIM , but not posttreatment. Elevated anti-inflammatory IL-10 significantly decreased after three months in serum, while saliva oxytocin concentrations increased in CRPS subjects after L4-DRGSTIM (p = 0.65). No severe implantation and stimulation associated adverse events were recorded. Conclusions Selective L4-DRGSTIM improved neuropathic pain and functional impairment in CRPS as previously reported. CRPS patients displayed a pro-inflammatory molecular pattern in serum. Serum anti-inflammatory IL-10 significantly declined, while saliva oxytocin nonsignificantly increased after L4-DRGSTIM . An evidence-based relational interpretation of our study is limited due to the uncontrolled study design. However, molecular profiling of biofluids (saliva, serum) represents a novel and experimental field in applied neuromodulation, which warrant further investigations to unveil mechanisms of neuroimmune modulation.

The role and diagnostic value of the synovial complement system in patients with low-grade periprosthetic joint infection (PJI) are unclear. We sought to evaluate, for the first time, the usefulness of synovial complement factors in these patients by measuring the individual synovial fluid levels of complement factors (C1q, C3b/iC3b, C4b, C5, C5a, C9, factor B, factor D, factor H, factor I, properdin, and mannose-binding lectin [MBL]). The patients (n = 74) were classified into septic (n = 28) and aseptic (n = 46). Receiver-operator characteristic curves and a multiple regression model to determine the feasibility of a combination of the tested cytokines to determine the infection status were calculated. The synovial fluid levels of C1q, C3b/C3i, C4b, C5, C5a, MBL, and properdin were significantly elevated in the PJI group. The best sensitivity and specificity was found for C1q. The multiple regression models revealed that the combination of C1q, C3b/C3i, C4b, C5, C5a, and MBL was associated with the best sensitivity (83.3%) and specificity (79.2%) for a cutoff value of 0.62 (likelihood ratio: 4.0, area under the curve: 0.853). Nevertheless, only a combined model showed acceptable results. The expression patterns of the complement factors suggested that PJI activates all three pathways of the complement system.

The undifferentiated pleomorphic sarcoma (UPS) is a part of the soft tissue sarcoma group and represents almost 10% of all soft tissue sarcomas. The case of a 49-year-old patient is presented who was diagnosed with a primary UPS in the left gluteus maximus muscle, which was treated with compartmental resection with adjuvant radiotherapy (60 Gy). During tumor follow-up (3 years later) a locoregional metastasis at an unusual location in the quadratus femoris muscle was detected, which was treated by in toto resection with intraoperative radiotherapy (10 Gy). The intra and postoperative outcome was without complications and without neurological deficits. In the last follow-up, 6 months postoperatively, the patient was free of tumors and symptoms.Das undifferenzierte pleomorphe Sarkom („undifferentiated pleomorphic sarcoma“ [UPS]) gehört zur Gruppe der Weichteilsarkome und macht fast 10 % aller Weichteilsarkome aus. Der Fall eines 49-jährigen Patienten wird vorgestellt, bei dem die kompartmentorientierte Resektion eines primären UPS im linken Musculus gluteus maximus mit adjuvanter Radiotherapie (60 Gy) durchgeführt wurde. Im Rahmen der Tumornachsorge (3 Jahre später) wurde eine lokoregionäre Metastase an einer ungewöhnlichen Lokalisation im M. quadratus femoris festgestellt, welche mittels einer In-toto-Resektion mit intraoperativer Radiotherapie (10 Gy) behandelt wurde. Der intra- und postoperative Verlauf gestalten sich komplikationslos ohne neurologische Defizite. Im Rahmen der Nachtuntersuchung 6 Monate postoperativ war der Patient tumor- und beschwerdefrei.

Implantation of custom-made acetabular components (CMAC) with load transmission onto the remaining bone stock and reconstruction of the "center of rotation" (COR) in cases of severe periacetabular bone defects.Severe periacetabular bone loss (Paprosky type IIIA/B) with or without pelvic discontinuity after septic or aseptic loosening with inadequate load capacity of the dorsal pillar and/or large supraacetabular defects.Acute or local infections, lack of compliance, taking into account the risks and complications: missing or limited expected postoperative functional gain, multimorbid patients with potential inoperability during the first and/or second intervention.Lateral transgluteal or posterolateral approach while protecting neurovascular and muscular structures. Preparation of the implant site based on preoperative planning with augmentation of bone defects as far as possible. Primarily stable anchoring with 2 angle-stable pole screws in the ilium, an optional pole screw in the pubic bone for determination of COR, and stabilization screws in the iliac wing (optionally angle-stable). Use of dual mobility cup according to the soft tissue tension and intraoperative stability.For the first 6 weeks postoperative partial weight-bearing (20 kg), followed by a gradual increase of the load (10 kg per week).Between 2008 and 2018, 47 patients with a Paprosky type III defect underwent implantation of a monoflanged CMAC. Main complication was a periprosthetic joint infection with subsequent need for implant removal in 9 of 10 cases. Harris Hip Score improved from 21.1 to 61.5 points. X‑ray imaging displayed an angle of inclination of 42.3 ± 5.3°, an anteversion of 16.8 ± 6.2°, a ∆ H of 0.5 ± 0.2 mm and a ∆ V of 17.7 ± 1.1 mm according to Roessler et al.OPERATIONSZIEL: Implantation von „custom-made acetabular components“ (CMAC) mit direkter Kraftübertragung auf den verbliebenen Knochen in der Hauptbelastungszone und Rekonstruktion des „center of rotation“ (COR) zur Wiederherstellung der Gelenkbiomechanik bei ausgeprägten periazetabulären Knochenverlusten.Azetabuläre Knochendefekte (Typ Paprosky IIIA/B) mit und ohne begleitende Beckendiskontinuität mit fehlender Tragfähigkeit des dorsalen Pfeilers und/oder großen supraazetabulären Defekten.Lokale oder systemische Infektionen, mangelnde Compliance, in Abwägung der eingriffsspezifischen Risiken und Komplikationen fehlender oder eingeschränkt zu erwartender postoperativer Funktionsgewinn, multimorbide Patienten mit potenzieller Inoperabilität beim Erst- und/oder Zweiteingriff.Eingehen über einen lateralen oder posterolateralen Zugang unter Schonung neurovaskulärer sowie muskulärer Strukturen. Vorbereitung des Implantatlagers anhand der präoperativen Planung und biologische Defektaugmentation kavitärer Defekte. Primärstabile Verankerung mit 2 Pfahlschrauben im Os ilium, optional Pfahlschraube ins Os pubis zur Bestimmung des COR und Laschenschrauben (optional winkelstabil). Optional Verwendung von zementierten Dual-Mobility-Pfannen in Anbetracht der Weichteilspannung und der intraoperativen Stabilität, insbesondere bei insuffizienter pelvitrochantärer Muskulatur.Für 6 Wochen postoperativ Teilbelastung mit 20 kg Körpergewicht, anschließend Aufbelastung mit 10 kg Körpergewicht pro Woche.Zwischen 2008 und 2018 wurde bei 47 Patienten ein CMAC mit einer großflächig aufliegenden Iliumlasche (Monoflange) bei einem Paprosky-Typ-III-Defekt implantiert. Als Hauptkomplikation ist die periprothetische Protheseninfektion (PPI) zu nennen, welche in 9 von 10 Fällen (90 %) ursächlich für die Explantation war. Der HHS bei letzter Vorstellung verbesserte sich von 21,1 auf 61,5 Punkte. Nativradiologisch zeigten sich ein Inklinationswinkel von 42,3 ± 5,3°, eine Anteversion von 16,8 ± 6,2° sowie ein ∆ H von 0,5 ± 0,2 mm bei einem ∆ V von 17,7 ± 1,1 mm nach Roessler et al.

Background: Failed reconstruction in cases of severe acetabular bone loss, with or without pelvic discontinuity, in revision total hip arthroplasty (rTHA) remains a great challenge in orthopaedic surgery. The aim of this study was to describe the outcome of a “second” rTHA with “custom-made acetabular components (CMACs)” after a previously failed reconstruction with CMACs. Methods: 4 patients with severe acetabular bone loss (Paprosky Type IIIB), who required a second rTHA after a previously failed reconstruction with CMAC, due to prosthetic joint infection (PJI), were included in our retrospective study. All prostheses had been constructed on the basis of thin-layer computed-tomography scans of the pelvis. The second rTHA was considered unsuccessful in the event of PJI or aseptic loosening (AL) with need for renewed CMAC explantation. Results: The treatment success rate after second rTHA with a CMAC was 50% (2 of 4). In the successful cases, the visual analogue scale (VAS) score and Harris Hip Score (HHS) after the second rTHA (VAS range 2–4; HHS range 45–58 points) did not differ from those after the first rTHA, before onset of symptoms (VAS: range 2–4; HHS: range 47–55 points). In the failed cases, the second CMACs needed to be explanted due to PJI, with renewed detection of previous pathogens. Patients with treatment failure of the second CMAC had required a higher number of revision surgeries after explantation of the first CMAC than patients with a successful outcome. Conclusions: In patients with severe acetabular bone loss and previously failed rTHA with CMACs, repeat rTHA with a CMAC may be a solid treatment option for patients with an “uncomplicated” multi-stage procedure, i.e., without persisting infection after explantation of the original CMAC. While the outcome in terms of clinical function does not appear negatively affected by such a “second attempt,” the complication rate and risk of reinfection, nonetheless, is high.

Osteoporosis is a disease characterized by low bone mass and an increased risk of fractures. Although several cellular players leading to osteoporosis have been identified, the role of mesenchymal stromal cells (MSC) is still not fully elaborated. The aim of this study was, therefore, to isolate and characterize MSCs from vertebral body of healthy non-osteoporotic and osteoporotic patients, with a particular focus on their osteogenic differentiation potential. Isolated MSCs were characterized by their osteogenic, adipogenic, and chondrogenic differentiation, as well as surface marker expression, proliferation behavior, and immunomodulatory capacity. The mineralization process was confirmed using Alizarin Red S and alkaline phosphatase (ALP) stains and further evaluated by determining ALP activity, mineral deposition, and free phosphate ion release. MSCs from both healthy and osteoporotic patients showed common fibroblast-like morphology and similar proliferation behavior. They expressed the typical MSC surface markers and possessed immunomodulatory capacity. Both groups demonstrated solid trilineage differentiation potential, osteogenic differentiation was further confirmed by increased ALP activity, deposition of inorganic crystals, phosphate ion release, and expression of osteoblast marker genes. Overall, MSCs from osteoporotic and non-osteoporotic patients showed neither a difference in general MSC features nor in the detailed analysis regarding osteogenic differentiation. These data suggest that vertebral body MSCs from osteoporotic patients were not impaired, rather, they possessed full osteogenic potential compared to MSCs from non-osteoporotic patients.

Mesenchymal stromal cells (MSC) harvested in different tissues from the same donor exhibit different phenotypes. Each phenotype is not only characterized by a certain pattern of cell surface markers, but also different cellular functionalities. Only recently were different harvesting and processing techniques found to contribute to this phenomenon as well. This study was therefore set up to investigate proteomic and functional properties of human bone marrow-derived MSCs (hBM-MSC). These were taken from the same tissue and donor site but harvested either as aspirate or bone chip cultures. Both MSC populations were profiled for MSC markers defined by the International Society for Cellular Therapy (ISCT), MSC markers currently under discussion and markers of particular interest. While classic ISCT MSC markers did not show any significant difference between aspirate and outgrowth hBM-MSCs, our additional characterization panel revealed distinct patterns of differentially expressed markers. Furthermore, hBM-MSCs from aspirate cultures demonstrated a significantly higher osteogenic differentiation potential than outgrowth MSCs, which could be confirmed using a transcriptional approach. Our comparison of MSC phenotypes obtained by different harvesting techniques suggests the need of future standardized harvesting, processing and phenotyping procedures in order to gain better comparability in the MSC field.

Periprosthetic joint infection (PJI) is a feared complication after arthroplasty. Our hypothesis was that PJI caused by difficult-to-treat (DTT) pathogens has a worse outcome compared with non-DTT PJI. Routine clinical data on 77 consecutive patients with confirmed PJI treated with 2-stage exchange arthroplasty were placed in DTT and non-DTT PJI groups and analyzed. The main outcome variable was that the patient was definitively free of infection after 2 years. We found definitive infection resolution in 31 patients in the DTT group (68.9%) and 28 patients (87.5%) in the non-DTT group (P < 0.05). The necessity for revision surgery until assumed resolution of infection was significantly more frequent in the DTT group with 4.72 ± 3.03 operations versus 2.41 ± 3.02 operations in the non-DTT group (P < 0.05). PJI caused by DTT bacteria is associated with significantly higher numbers of revision operations and significantly inferior definitive infection resolution.

Currently, there is an increasing focus on mesenchymal stromal cells (MSC) as therapeutic option in bone pathologies as well as in general regenerative medicine. Although human MSCs have been extensively characterized and standardized, ovine MSCs are poorly understood. This limitation hampers clinical progress, as sheep are an excellent large animal model for orthopedic studies. Our report describes a direct comparison of human and ovine MSCs from three corresponding sources under the same conditions. All MSCs presented solid growth behavior and potent immunomodulatory capacities. Additionally, we were able to identify common positive (CD29, CD44, CD73, CD90, CD105, CD166) and negative (CD14, CD34, CD45, HLA-DR) surface markers. Although both human and ovine MSCs showed strong osteogenic potential, direct comparison revealed a slower mineralization process in ovine MSCs. Regarding gene expression level, both human and ovine MSCs presented a comparable up-regulation of Runx2 and a trend toward down-regulation of Col1A during osteogenic differentiation. In summary, this side by side comparison defined phenotypic similarities and differences of human and ovine MSCs from three different sources, thereby contributing to a better characterization and standardization of ovine MSCs. The key findings shown in this report demonstrate the utility of ovine MSCs in preclinical studies for MSC-based therapies.