Results of a monocentric field study: value of histology compared to sonication method and conventional tissue culture in the diagnosis of periprosthetic joint infection (PJI).

BACKGROUND: To confirm the diagnosis of periprosthetic joint infection (PJI), the Infectious Diseases Society of America (IDSA) and the International Consensus Meeting (ICM) have defined criteria that include histology as a minor criterion and the sonication method only as an additional criterion. The aim of this monocentric, retrospective study was to investigate the value of histology and whether sonication leads to a more accurate diagnosis. MATERIALS AND METHODS: All revision surgeries for knee and hip arthroplasty between 2017 and 2020 were included. With regard to microbiological diagnostic, conventional culture of periprosthetic biopsies and sonication of explant material were performed. In addition, histology and non-specific inflammatory markers (CRP, leukocytes) were recorded. RESULTS: A total of 78 patients with PJI and 62 aseptic controls were included. From both microbiological methods (conventional culture / sonication), Staphyloccus (S.) epidermidis and S. aureus were detected most frequently. However, compared to the conventional microbiology, a higher sensitivity was calculated for sonication, albeit with a lower specificity in relation to a PJI. In two logistic regression models for the significance of all diagnostic parameters in PJI, the AUC was 0.92 and 0.96 with histology in particular making the decisive contribution in both models (p < 0. 001, both models). CONCLUSION: Since histology showed the highest accuracy in the current study, its importance in the PJI criteria should be reevaluated. Sonication shows a high sensitivity for germ detection with a lower specificity and should only be used in combination with the conventional culture for microbiolgical diagnostics.

Are Process Changes Measurable? An Analysis of 4136 Proximal Femur Fractures over 16 Year. / Sind Prozessänderungen messbar? Eine Analyse über 16 Jahre mit 4163 proximalen Femurfrakturen.

Prozessänderungen im perioperativen Setting werden selten analysiert, weil ihre Ergebnisse nicht unmittelbar fassbar sind und es einer hohen Fallzahl bedarf. Primäres Ziel war es, Prozessänderungen retrospektiv anhand proximaler Femurfrakturen (PF) zu evaluieren und deren Effekt mit verschiedenen Zielkriterien zu überprüfen. Sekundäres Ziel war die Definition möglicher Qualitätskriterien für die Versorgung von PF.Retrospektive Analyse der Datenbank eines Level-1-Traumazentrums zu PF. Eingeschlossen wurden alle osteosynthetisch und endoprothetisch versorgten PF im Behandlungszeitraum vom 01.01.2006 bis 31.12.2021. Der Zeitraum von 16 Jahren wurde für die Statistik trichotom aufgeteilt und die ersten 6 Jahre als Ausgangsbasis verwendet. Insgesamt 10 Prozessänderungen wurden in den folgenden 10 Jahren vorgenommen. Die Auswirkungen dieser Änderungen wurden anhand 1. der operativen Revisionsrate, 2. der Infektionsrate, 3. der perioperativen Transfusionsrate sowie 4. der 1-Jahres-Letalität überprüft.Insgesamt 4163 PF wurden analysiert. Hinsichtlich der Zielkriterien zeigten die Änderungen der ersten 5 Jahre (2012-2016; intramedulläres Verfahren für Osteosynthesen sowie Einwegabdeckung und Einwegkittel) den stärksten Effekt mit einer erstmaligen Senkung der operativen Revisionsrate unter 10% auf Dauer. Weitere Prozessoptimierungen der letzten 5 Jahre (2017-2021) erbrachten ebenfalls messbare Verbesserungen (Senkung der Infektions- und Transfusionsrate). Die 1-Jahres-Letalität blieb unverändert, auch während der COVID-19-Pandemie.Prozessänderungen bei PF führen nicht unmittelbar zu objektiv messbaren Verbesserungen. Rückblickend erscheint der Paradigmenwechsel von extra- auf intramedulläre Osteosynthese den höchsten Effekt erzielt zu haben, wenngleich über die letzten 10 Jahre eine schrittweise Besserung aller Zielkriterien eintrat - mit Ausnahme der Letalität. Als objektive Qualitätskontrolle sollte eine 1-Jahres-Revisionsrate unter 10% angestrebt sein.

Therapy aspects of peri-implant femoral fractures-a retrospective analysis of 64 patients.

PURPOSE: The incidence of peri-implant femoral fractures (PIFF) is increasing. Information regarding outcomes, timing of surgery, risk factors, and a clinically applicable treatment algorithm are lacking. The aim of this study was to identify outcome-related risk factors and to derive a treatment algorithm. METHODS: Sixty-four PIFFs treated between 01.01.2006 and 31.12.2020 in a level I trauma centre were evaluated retrospectively for fracture pattern, surgical technique, risk factors, complications, and 1-year mortality. The study was approved by the ethics committee (No. 21-2714-104). RESULTS: One-year mortality was 24.1%. Surgical complications occurred in 4.7%, and general complications in 15.6% of the patients. General complications, low haemoglobin level at admission, elevated CHA2DS2-VASc, and Charlson score resulted in increased 1-year mortality. Time to surgery > 24 h did not increase complication or mortality rates. The three predominant fracture patterns were fractures close or distal to cephalomedullary nails, close or proximal to distal lateral plates, and close or distal to sliding hip screws. Recommendations for surgical treatment were derived: Osteosynthesis should enable as much weight-bearing as possible; the initial implant should only be removed, if this is essential for the new osteosynthesis; lateral locking plates should span the whole femur; antegrade nails should have a cephalomedullary component to avoid consecutive femoral neck fractures; implants should overlap to reduce the risk of consecutive inter-implant fractures. CONCLUSION: Risk factors for 1-year mortality in patients with PIFFs were identified. A treatment algorithm and general principles for surgery of PIFFs were developed.

[Postoperative outcome of 30 patients with navicular bone fractures-In connection with AOFAS-Score, SF-12 and fracture classifications]. / Das postoperative Outcome von 30 Patienten mit Os-naviculare-Fraktur ­ im Zusammenhang mit AOFAS-Score, SF-12 und Frakturklassifikationen.

BACKGROUND: Fractures of the navicular bone are rare and the number of those treated surgically is even smaller. Moreover, scientific analyses on this topic are only sporadically present in the literature, therefore this retrospective and monocentric study was initiated. METHODS: A total of 30 patients with 30 fractures were included. With the exception of one primary fusion, all patients underwent open reduction with internal osteosynthesis. Clinical and radiological follow-up was performed at least 2 years postoperatively using AOFAS-Score, SF-12 and a radiological examination. The primary objectives were the clinical and radiologic outcomes as mid-term to long-term outcomes. The secondary objective was to compare these results with two existing computed tomography (CT) fracture classifications in terms of their association with the outcome. RESULTS: The median follow-up was 7.8 years (range 2-16.2 years) postoperatively. One patient suffered an infection, four patients required secondary arthrodesis and eight patients had to change their occupation. The mean AOFAS-Score was 80.8/100 and the mean physical and mental SF-12 component summary scores were 47.1 and 55.7 points, respectively. Male sex and arthrodesis were associated with worse outcomes in both scores but not patient age or ipsilateral concomitant injuries. Both CT fracture classifications showed low predictive value. CONCLUSION: The severity of the injury in the preoperative CT showed no connection with the clinical outcome in the AOFAS-Score and SF-12 scores. Posttraumatic osteoarthritis and secondary arthrodesis are associated with a poor outcome. In the course of the observational period the reduction results improved, which was accompanied by a better clinical outcome.

Surgery Within 24 Hours Reduces Mortality and General Complication Rates in Patients Who Have Periprosthetic Femoral Fractures at the Hip.

BACKGROUND: In patients who have hip fractures, treatment within 24 hours reduces mortality and complication rates. A similar relationship can be assumed for patients who have hip periprosthetic femoral fractures (PPFs) owing to the similar baseline characteristics of the patient populations. This monocentric retrospective study aimed to compare the complication and mortality rates in patients who had hip PPF treated within and after 24 hours. METHODS: In total, 350 consecutive patients who had hip PPF in a maximum-care arthroplasty and trauma center between 2006 and 2020 were retrospectively evaluated. The cases were divided into 2 groups using a time to surgery (TTS) of 24 hours as the cutoff value. The primary outcome variables were operative and general complications as well as mortalities within 1 year. RESULTS: Overall, the mean TTS was 1.4 days, and the 1-year mortality was 14.6%. The TTS ≤ 24 hours (n = 166) and TTS > 24 hours (n = 184) groups were comparable in terms of baseline characteristics and comorbidities. Surgical complications were equally frequent in the 2 groups (16.3 versus 15.2%, P = .883). General complications occurred significantly more often in the late patient care group (11.4 versus 28.3%, P < .001). In addition, the 30-day mortality (0.6 versus 5.5%, P = .012), and 1-year mortality (8.3 versus 20.5%, P = .003) rates significantly increased in patients who had TTS > 24 hours. Cox regression analysis yielded a hazard ratio of 4.385 (P < .001) for the TTS > 24 hours group. CONCLUSIONS: Prompt treatment is required for patients who have hip PPF to reduce mortality and overall complications.

Locking plate for periprosthetic femoral fractures according to Vancouver C: Outcome and radiological subanalysis of 40 patients.

PURPOSE: Periprosthetic femoral fractures (PFF) according to type Vancouver C are less common and outcome is limited reported. Therefore, we conducted this retrospective single center study. METHODS: We performed analysis of patients who underwent open reduction and internal fixation (ORIF) with locking plates for PPF occurring distally of a primary standard hip stem. Data on demographics, revisions, fracture patterns, and mortality were evaluated. At least two years after operation, we examined outcome using the Parker and Palmer mobility score. Primary aim of this study was revision, outcome and mortality. Secondary aim was evaluation of fracture subtypes within type Vancouver C fractures. RESULTS: Between 2008 and 2020, 383 patients with periprosthetic femoral fracture after hip replacement were surgically treated according to our database. Among them, 40 patients (10.4%) with type Vancouver C fractures were enrolled for this study. The mean patient age was 81.5 years (59-94) at the time of fracture. Thirty-three patients were women, and 22 fractures were on the left side. Without exception, locking plates were used. The 1-year mortality rate for the sample was 27.5% (n = 11). Three revisions (7.5%) were performed for plate breakage. Rate of infection and non-union was zero. Three different fracture patterns were assessed: (1) transverse or oblique fractures below the tip of the stem (n = 9); (2) spiral-shaped fractures within the diaphysis (n = 19); and (3) burst fractures at the supracondylar region (n = 12). Demographic or outcome effects between fracture patterns were not found. On average of 4.2 years (2.0-10.4) after treatment, the mean reported Parker score was 5.5 (1-9). CONCLUSION: ORIF with a single lateral locking plate is safe for type Vancouver C fractures with a well-fixed hip stem. Therefore, we do not recommend routinely revision arthroplasty or orthogonal double plating. Three subtypes of fractures within Vancouver C demonstrated no significant differences in baseline data and outcome.

[Treatment aspects of interprosthetic femur fractures-retrospective analysis of 70 patients]. / Therapieaspekte interprothetischer Femurfrakturen ­ retrospektive Analyse von 70 Patienten.

BACKGROUND: Interprosthetic femur fractures (IFF) are rare injuries, whose surgical treatment is basically with osteosynthesis or revision arthroplasty. Various therapy algorithms have been proposed based on very small study collectives. Factors influencing the outcome are not known. OBJECTIVES: The aim of the retrospective monocentric study is to derive a treatment algorithm based on a large number of cases and to identify factors influencing the outcome. MATERIALS AND METHODS: Between 2006 and 2020, 70 IFF were identified. The surgical treatment comprised 38 osteosyntheses, 30 revision arthroplasties and 2 amputations. With classification and time to surgery, 69 perioperative variables were recorded. General and operative complications, as well as mortality, were determined in the follow-up period of 1 year. RESULTS: ASA and Charlson score correlated with 1­year-mortality. In addition, preoperatively increased CRP levels, reduced hemoglobin and the CHA2DS2-VASc score were identified as factors influencing mortality. Surgery within 24 h showed a trend towards fewer general complications. Transferred patients indicated an increased mortality. Based on classification according to Pires et al. or Füchtmeier et al. no clear treatment decision could be made. Relevant criteria for the surgical treatment were fracture localization, implant stability, bone vitality, anchoring possibility of the revision stem, as well as general condition of the patient. CONCLUSIONS: The identified factors influencing the outcome correspond to those of patients with hip fractures. IFF should be treated timely. A treatment path was developed on the basis of the largest patient group to date.

How Relevant Is the Parallax Effect on Low Centered Pelvic Radiographs in Total Hip Arthroplasty.

The correct cup position in total hip arthroplasty (THA) is usually assessed on anteroposterior low centered pelvic radiographs, harboring the risk of misinterpretation due to projection of a three-dimensional geometry on a two-dimensional plane. In the current study, we evaluate the effect of this parallax effect on the cup inclination and anteversion in THA. In the course of a prospective clinical trial, 116 standardized low centered pelvic radiographs, as routinely obtained after THA, were evaluated regarding the impact of central beam deviation on the cup inclination and anteversion angles. Measurements of the horizontal and vertical beam offset with two different methods of parallax correction were compared with each other. Furthermore, the effect of parallax correction on the accuracy ofmeasuring the cup position was investigated. The mean difference between the two parallax correction methods was 0.2° ± 0.1° (from 0° to 0.4°) for the cup inclination and 0.1° ± 0.1° (from -0.1° to 0.2°) for the anteversion. For a typically intended cup position of a 45° inclination and 15° anteversion, the parallax effect led to a mean error of -1.5° ± 0.3° for the inclination and 0.6° ± 1.0° for the anteversion. Central beam deviation resulted in a projected higher cup inclination up to 3.7°, and this effect was more prominent in cups with higher anteversion. In contrast, the projected inclination decreased due to the parallax effect up to 3.2°, especially in cups with high inclination. The parallax effect on routinely obtained low centered pelvic radiographs is low and not clinically relevant due to the compensating effect of simultaneous medial and caudal central beam deviation.

[Operative treatment of distal radial fractures under vitamin K antagonist or DOAC : Is preoperative interruption of these drugs necessary?] / Die operative Versorgung distaler Radiusfrakturen unter Marcumar oder DOAC : Ist ein präoperatives Absetzen der Medikation erforderlich?

BACKGROUND: Scientific data on emergency operations during ongoing treatment with vitamin K antagonists or with direct oral anticoagulants (DOAC) are lacking, because interruption or bridging of this treatment is routinely performed for up to several days. To reduce time delays and to simplify this procedure, we perform operations of distal radial fractures immediately and without interruption of antithrombotic medication. MATERIAL AND METHODS: For this retrospective and monocentric study, we included only patients with distal radial fractures treated within 12 h after diagnosis with open reduction and volar plating and who received anticoagulation with a vitamin K antagonist or DOAC. Primary aim of the study was evaluation of specific complications, such as revision due to bleeding or hematoma formation and secondary aims were thromboembolic events or infections. The endpoint was 6 weeks after the operation. RESULTS: Between 2011 and 2020, 907 consecutive patients with distal radial fractures were operatively treated. Of these, 55 patients met the inclusion criteria. The mean age was 81.5 Jahre (63-94 years) and women (n = 49) were primarily affected. All operations were performed without tourniquets. With a study endpoint 6 weeks after operation, no revisions were performed for bleeding, hematoma, or infection and primary wound healing was assessed for all patients. One revision was performed for fracture dislocation. Thromboembolic events were also not documented. CONCLUSION: In this study the treatment of distal radial fractures within 12 h and without interruption of antithrombotic treatment was not associated with any imminent systemic complications. This applies to both vitamin K antagonists and DOAC; however, higher case numbers must confirm our results.

[Survival of proximal femoral fractures vs. mean life expectancy of the general population : Retrospective analysis of 1000 geriatric patients minimum 10 years after operation]. / Überlebenszeit proximaler Femurfrakturen vs. mittlere Lebenserwartung der Allgemeinbevölkerung : Retrospektive Analyse 1000 geriatrischer Patienten mindestens 10 Jahre postoperativ.

BACKGROUND: Surgery for geriatric proximal femoral fractures (PF) is associated with high mortality rates within the first year. Studies with follow-up of at least 10 years after surgery are lacking. MATERIAL AND METHODS: Based on our database, we reviewed patients with PF who underwent surgery and were followed for a minimum of 10 years. Only patients aged 65-99 years were included. The primary endpoint was survival compared to the mean life expectancy of the general population evaluated by the German Federal Statistical Office. The secondary endpoint was any revision later than 1 year after surgery. After a minimum of 10 years telephone calls were conducted with living patients or their relatives. RESULTS: From a total of 1203 consecutive patients 1000 patients with 1000 PF were evaluated after a mean of 12.2 years (range 10.0-14.0 years). The mean survival was 4.5 ± 1.6 years, and the 10-year survival rate was 13.1%. A total of 7 periods with a range of 5 years were analyzed, starting from 65-69 years up to 95-99 years. Compared to the mean life expectancy of the general population, the survival rate of the sample was significantly shorter up to 9 years. Both genders were equally affected. With increasing age, this gap declined based on shorter life expectancy. A subgroup analysis revealed that patients with survival > 1 year did not demonstrate significantly better results. Revisions later than 1 year after the index surgery were infrequent, and only 27 (2.7%) were recorded. CONCLUSION: Geriatric patients with PF have significantly shorter life expectancy than the general population evaluated by the German Federal Statistical Office. This reflects fragility and morbidity of patients with PF.

Two-thousand hip fractures treated within 12 h and > 12-24 h after admission: Are survival and adverse events affected?

BACKGROUND: The effects of immediate operation on hip fracture (HF) are unclear. Therefore, we investigated the influence of time to operation within 12 h vs. > 12-24 h on survival and adverse events. METHODS: This retrospective study was based on our database from 2006 to 2019. Patients ≥ 20 years of age with operations for HF were included. A total of 40 characteristics were analyzed for operations within 12 h (group 1) and > 12-24 h (group 2) after admission. The primary endpoint was survival at 1 year after operation. Secondary endpoints were revision surgery for any reason, infection, and serious adverse events. RESULTS: A total of 1015 patients received operations within 12 h (group 1), and 985 patients received operations > 12-24 h (group 2) after admission. The mean age of the patients was 78.8 ± 12.3 years. Patients in group 1 were younger and had better health status and shorter hospitalizations than those in group 2. However, no differences were found for revision surgery, infection or adverse events. The mortality rates at 30 days, 90 days, 6 months, and 1 year were 6.2, 11.8, 15.9, and 21.0%, respectively. The mortality rate at day 30 was significantly better (p = 0.04) in group 1, but no further differences in survival were observed (hazard ratio 1.071; 95% confidence interval 0.864-1.328; log rank 0.179). A subgroup analysis of geriatric patients ≥ 65 years assessed no differences according the primary and secondary endpoints. CONCLUSIONS: Within the limits of single-center analysis, the patients receiving treatment for HF within 12 h were younger and healthier and had the benefits of shorter hospitalizations and a higher 30-day survival rate than patients treated > 12-24 h after admission. At the endpoint 1 year after operation, no differences were observed in adverse events or survival rates.

Alpha-particle emitting 213Bi-anti-EGFR immunoconjugates eradicate tumor cells independent of oxygenation.

Hypoxia is a central problem in tumor treatment because hypoxic cells are less sensitive to chemo- and radiotherapy than normoxic cells. Radioresistance of hypoxic tumor cells is due to reduced sensitivity towards low Linear Energy Transfer (LET) radiation. High LET α-emitters are thought to eradicate tumor cells independent of cellular oxygenation. Therefore, the aim of this study was to demonstrate that cell-bound α-particle emitting (213)Bi immunoconjugates kill hypoxic and normoxic CAL33 tumor cells with identical efficiency. For that purpose CAL33 cells were incubated with (213)Bi-anti-EGFR-MAb or irradiated with photons with a nominal energy of 6 MeV both under hypoxic and normoxic conditions. Oxygenation of cells was checked via the hypoxia-associated marker HIF-1α. Survival of cells was analysed using the clonogenic assay. Cell viability was monitored with the WST colorimetric assay. Results were evaluated statistically using a t-test and a Generalized Linear Mixed Model (GLMM). Survival and viability of CAL33 cells decreased both after incubation with increasing (213)Bi-anti-EGFR-MAb activity concentrations (9.25 kBq/ml-1.48 MBq/ml) and irradiation with increasing doses of photons (0.5-12 Gy). Following photon irradiation survival and viability of normoxic cells were significantly lower than those of hypoxic cells at all doses analysed. In contrast, cell death induced by (213)Bi-anti-EGFR-MAb turned out to be independent of cellular oxygenation. These results demonstrate that α-particle emitting (213)Bi-immunoconjugates eradicate hypoxic tumor cells as effective as normoxic cells. Therefore, (213)Bi-radioimmunotherapy seems to be an appropriate strategy for treatment of hypoxic tumors.