The optimal diagnostic cut-off of WBC and PMN counts for joint aspiration in periprosthetic joint infection is 2479/µL and 67%, respectively: ICM criteria thresholds are too high.

BACKGROUND: Various organizations have published definitions for periprosthetic joint infection (PJI) with significant differences in the cut-offs of white blood cell (WBC) count and polymorphonuclear (PMN) leukocyte cells. Herein, we aim to analyze optimal cut-offs in patients which are planned to undergo a prosthesis revision and compare them with the actual published thresholds of the International Consensus Meeting (ICM) and European Bone and Joint Infection Society (EBJIS). METHODS: A test kit was compiled in a monocentric prospective study, according to the ICM criteria (2018) and 2021 EBJIS criteria. The kit was implemented using: blood samples (including leukocyte count and C-reactive protein); samples for examining the synovial fluid (WBC count, PMN cell differentiation, microbiological culture for incubation over 14 days, alpha-defensin ELISA laboratory test, and leukocyte-esterase test). The cut-offs for WBC and PMN counts were investigated using ROC analyses and Youden index. The ICM 2018 criteria were applied, using alpha-defensin in all cases. Patients which have to undergo a prosthesis revision were included, a pre-operative joint aspiration had been performed, and the patients had been followed up prospectively. RESULTS: 405 patients were examined with the compiled test kit; 100% had a complete dataset with respect to alpha-defensin; 383 patients, according to WBC count; and 256, according to PMN cell differentiation The cut-off of 2478.89 cells/µl in the WBC count (sensitivity: 87.70%; specificity: 88.10%) and the cut-off of 66.99% in PMN differentiation showed the best accuracy (sensitivity: 86.00%; specificity: 88.80%). Other published cut-offs for WBC were tested in this cohort and showed the following accuracy: 3000/µl (EBJIS/ICM; sensitivity: 82.10%; specificity: 91.00%), 2000/µl (sensitivity: 89.60%; specificity: 83.40%), and 1500/µl (sensitivity: 91.50%; specificity: 75.00%). The published cut-offs for PMN had the following accuracy in this cohort: 80% (ICM; sensitivity: 66.3%; specificity: 96.50%), 70% (sensitivity: 82.6%; specificity: 90%), and 65% (EBJIS, sensitivity: 86%; specificity: 88.8%). CONCLUSIONS: This study aims to improve current cut-offs for PMN- and WB-Count, even though PJI diagnosis is based on the combination of all defined tests. The optimal diagnostic cut-off of WBC and PMN counts was found to be 2479/µL and 67%, respectively, whereas ICM cut-offs in this cohort seem too high, as they provide high specificity but very low sensitivity. On the other hand, a cut-off for WBC count of 1500/µl alone would be very low, leading to low specificity and very high suspicion of PJI. The current consensus guidelines could be actualized considering these results to significantly improve the diagnostic quality. LEVEL OF EVIDENCE: II.

Modular knee arthrodesis secures limb, mobility, improves quality of life, and leads to high infection control in periprosthetic knee infection, when revision knee arthroplasty is not an option.

INTRODUCTION: This study compared the outcome of knee arthrodesis versus hinged total knee arthroplasty (TKA) in patients suffering from periprosthetic joint infection (PJI). METHODS: 104 patients with PJI were treated using a two-stage exchange of failed TKA. In case of non reconstructable bone loss or loss of extension mechanism, a modular intramedullary arthrodesis nail was used for reimplantation [Knee Arthrodesis Module (KAM); n = 52]. The control group was retrospectively matched treated using a hinged revision TKA [Rotating Hinge Knee (RHK); n = 52]. PJI remission rates, functional outcome (WOMAC; KSS) and quality of life (SF-12), as well as comorbidities and pain were evaluated. RESULTS: Mean age was 72.5 years. Charlson Comorbidity Index was higher in the KAM group (3.3 vs. 2.8). PJI remission rate was 89.4% (88.5% vs. 90.4%, respectively). In case of reinfection, implant retention was mostly possible in the RHK group (7.7%), whereas amputations were mostly performed in the KAM group (9.6%). Significant pain reduction (VAS 7.9-2.8) was achieved in both groups. Walking distance was significantly reduced in the KAM groups versus the RHK group (504 vs. 1064 m). WOMAC and KSS function scores were significantly reduced in the KAM group (25 vs. 40 and 35 vs. 64). Only moderate reduction in quality of life in the KAM group was observed (SF-12 physical: 34 vs. 40; SF-12 mental: 51 vs. 56) respectively. CONCLUSIONS: Arthrodesis using a modular intramedullary nail is an alternative for limb salvage, pain reduction, and preservation of quality of life and everyday mobility, when revision TKA is not an option. This study presents the largest number of case, comparing the outcome after performing an arthrodesis versus hinged TKA after septic failed TKA.

Salvage procedure for chronic periprosthetic knee infection: the application of DAIR results in better remission rates and infection-free survivorship when used with topical degradable calcium-based antibiotics.

PURPOSE: Debridement, systemic antibiotics and implant retention (DAIR) is very successful for early periprosthetic joint infection (PJI), but can fail in late-onset cases. We selected patients with PJI who were unsuitable for two-stage exchange total knee arthroplasty (TKA) and compared the outcomes of DAIR with or without degradable calcium-based antibiotics. METHODS: All patients fulfilled the criteria for late-onset PJI of TKA, as defined by an International Consensus Meeting in 2013, but were unsuitable for multistage procedures and TKA exchange due to operative risk. Fifty-six patients (mean age: 70.6 years, SD ± 10.8), in two historical collectives, were treated using a single-stage algorithm consisting of DAIR without antibiotics (control group, n = 33, 2012-2014), or by DAIR following the implantation of degradable antibiotics as indicated by an antibiogram (intervention group, n = 23, 2014-2017). OSTEOSET® (admixed vancomycin/tobramycin), and HERAFILL-gentamicin® were used as carrier systems. The primary endpoint was re-infection or surgical intervention after DAIR. RESULTS: There were no significant differences between the two groups in terms of mean age, Charlson comorbidity index or the rate of mixed infections. Overall, 65.2% of patients achieved remission in the intervention group compared with only 18.2% in the control group (p < 0.001); 50% of re-infections in the intervention group even occurred after 36 months. Kaplan-Meier analysis showed that, compared with controls, the intervention group experienced significantly longer 3-year infection-free survival. CONCLUSION: DAIR shows poor efficacy in difficult-to-treat cases, as demonstrated in our control group, which had a re-infection rate of 81.8%. In contrast, a DAIR group receiving topical calcium-based antibiotics showed significantly higher 3-year infection-free survival. Therefore, the combination of DAIR and degradable antibiogram-based local antibiotics is a reasonable salvage procedure for this body of patients. This is important as the number of severely sick patients who are too old for appropriate PJI treatment is estimated to increase significantly due to demographic change.

[Treatment of carbon monoxide poisoning in Germany : A retrospective single center analysis]. / Behandlung von Kohlenmonoxidvergiftungen in Deutschland : Eine retrospektive Single-Center-Analyse.

BACKGROUND: The symptoms of acute carbon monoxide (CO) poisoning are unspecific, ranging from headaches to unconsciousness and death. In addition to acute symptoms, delayed severe neurological sequelae may occur. While a total of 440 deaths by CO poisoning were registered in Germany in 1999, a total of 594 patients died (0.73 per 100,000 inhabitants) in 2014 and in 2015 the number even increased to 648 deaths. A national database on clinical symptoms, course of illness or quality of care concerning CO poisoning does not yet exist. METHODS: The treatment data of patients admitted to the Hyperbaric Emergency Centre Wiesbaden (HEC) from 2013 to 2017 with CO poisoning formed the basis of the study. This was a comparative evaluation of patient demographics, poisoning sources, symptom spectrum, course of treatment and time intervals registered on the preclinical and clinical levels. RESULTS: From 2013 to 2017 a total of 476 patients (282 men and 194 women) with an average non-invasively measured CO-Hb of 15% (Q0.25 = 7.6%, Q0.75 = 22.3%) were treated with hyperbaric oxygen. Heaters (n = 131), charcoal barbecues (n = 93), fires (n = 90), hookahs (n = 78) and combustion engines (n = 37) were the most frequent CO sources identified. Headaches, vertigo, nausea and syncope were the most prevalent symptoms. A median of 91 min (Q0.25 = 53 min; Q0.75 = 147 min) passed between first medical contact and BGA-validated diagnosis. In total, 151 patients were transferred directly to the HEC, whereas 325 patients were secondarily transferred. The delay in this subgroup took 183 min (median Q0.25 = 138 min; Q0.75 = 248 min). After receiving the first hyperbaric treatment, 80% were free of symptoms. Remaining symptoms included headache (10%), fatigue (8%), vertigo (5%) and nausea (3%) and 45 patients terminated further treatment. Of the patients 417 received a second hyperbaric treatment and 370 patients were treated 3 times. After the third treatment, 89% were free of symptoms and 5% still reported headaches, 3% vertigo and 2% fatigue. In total, 6 patients died and 430 patients were symptom-free after treatment. CONCLUSION: Commonly known sources (fire, charcoal grills) aside, many poisonings by smoking a hookah were observed. This study highlights the importance of considering CO poisoning as a differential diagnosis when encountering patients, especially of younger age, with non-specific neurological symptoms, as well as the importance of early initiation of treatment. A direct correlation between CO-Hb values (whether measured noninvasively or by invasive BGA) and the initial symptoms could not be demonstrated. In total, substantial time expired between the diagnosis and start of treatment of patients transported to a primary care hospital compared to those transported directly to the HEC. Although analysis showed adequate treatment with oxygen in the preclinical interval, administration of oxygen during primary hospital stay showed room for improvement. Introducing a national CO poisoning register and uniform treatment guidelines could improve in-house clinical processes. Multicenter studies are needed to close the gaps identified in the quality of care in Germany.

[Diagnosis and treatment of diving accidents. New German guidelines for diving accidents 2014-2017]. / Diagnostik und Behandlung von Tauchunfällen: Neue "Leitlinie Tauchun2014-2017".

In 2015 the German Society for Diving and Hyperbaric Medicine (GTÜM) and the Swiss Underwater and Hyperbaric Medical Society (SUHMS) published the updated guidelines on diving accidents 2014-2017. These multidisciplinary guidelines were developed within a structured consensus process by members of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI), the Sports Divers Association (VDST), the Naval Medical Institute (SchiffMedInst), the Social Accident Insurance Institution for the Building Trade (BG BAU), the Association of Hyperbaric Treatment Centers (VDD) and the Society of Occupational and Environmental Medicine (DGAUM). This consensus-based guidelines project (development grade S2k) with a representative group of developers was conducted by the Association of Scientific Medical Societies in Germany. It provides information and instructions according to up to date evidence to all divers and other lay persons for first aid recommendations to physician first responders and emergency physicians as well as paramedics and all physicians at therapeutic hyperbaric chambers for the diagnostics and treatment of diving accidents. To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose and the following key action statements: on-site 100% oxygen first aid treatment, still patient positioning and fluid administration are recommended. Hyperbaric oxygen (HBO) recompression remains unchanged the established treatment in severe cases with no therapeutic alternatives. The basic treatment scheme recommended for diving accidents is hyperbaric oxygenation at 280 kPa. For quality management purposes there is a need in the future for a nationwide register of hyperbaric therapy.

[Hindfoot arthrodesis for post-infectious ankle destruction using an intramedullary retrograde hindfoot nail]. / Die Rückfußarthrodese bei postinfektiöser Sprunggelenkdestruktion mit einem intramedullären retrograden Arthrodesennagel.

BACKGROUND: Limb salvage after operations with deep infections of the ankle is often successful using arthrodesis of the hindfoot. The aim of this study was to evaluate the results of arthrodesis using a retrograde intramedullary nail following post-infectious ankle destruction. PATIENTS AND METHODS: Between 2007 and 2010 a total of 44 patients were treated with tibiotalocalcaneal (TTC) arthrodesis and 14 patients with tibiocalcaneal (TC) arthrodesis using a retrograde hindfoot nail after quieting of infection. Evaluation included the American Orthopaedic Foot and Ankle Society (AOFAS) and the short-form 12-item (SF-12) scores. RESULTS: Of the 58 patients 49 (35 male and 14 female) could be followed-up. The average time of follow-up was 18 months and the mean age was 58 years. In 85.7 % bony union could be achieved and 10.2 % suffered from reinfections. The mean results achieved in the different scores were AOFAS 56 and SF-12 39.1 (physical health summary scale) and 46.1 (mental health summary scale). Statistical analysis showed a significantly higher rate of bony fusion for TTC arthrodesis. Bony non-union showed a significant correlation to patients with reinfection and to diabetic patients. CONCLUSIONS: Hindfoot arthrodesis for treatment of septic arthritis after infections is possible by using an intramedullary nail. The results show a high rate of fusion with an acceptable reinfection rate and good patient acceptance.

[Treatment of septic olecranon and patellar bursitis by excision and vacuum-assisted closure therapy]. / Die chirurgische Therapie der eitrigen Bursitis olecrani und praepatellaris mittels Exzision und Vakuumokklusion.

BACKGROUND: Treatment of septic olecranon and patellar bursitis differs considerably and is currently under discussion. We therefore performed a retrospective study of our patients with septic bursitis in the past 5 years. PATIENTS AND METHOD: Between March 2007 and February 2012 we treated 79 patients with septic olecranon (n = 43) and patellar (n = 36) bursitis surgically: 61-males, 18 females, age 51 (range: 11-91) years. Four patients had not been treated before, 25 had suffered recurrences after 1-10 previous procedures, and 9 patients had not improved after conservative therapy. 34 patients presented with traumatic rupture or fistula of their bursae. In all cases we performed a radical bursectomy and vacuum-assisted therapy for 4 to 5 days. In addition, patients received systemic antibiotics. We phoned all patients and were successful in 57 cases (72 %). We questioned these patients for range of movement, limitations at work, pain, sensibility disorder, satisfaction with the result and further surgical procedures. In all cases we took tissue specimens for cultures, in 48 preparations histological examination was performed. RESULTS: Microbiological and histological results are discussed in detail. 40 patients were free of complaints, 15 complained of mild pain, 54 of 57 had unlimited range of motion. Minor discomforts at desk work were reported by 5 of 43 patients, 12 out of 36 patient reported discomfort when performing on their knees. There was no recurrence in the period of investigation. CONCLUSION: We recommend our treatment concept for septic olecranon and patellar bursitis because patient satisfaction is high and recurrences are reliably avoided. The soft tissue is spared, so that plastic covering procedures are seldom necessary.

[Deep infection after treatment of proximal femur fractures--results and assessment of life quality]. / Die tiefe Infektion nach osteosynthetischer Versorgung hüftgelenknaher Femurfrakturen - Behandlungsergebnisse und Lebensqualität.

BACKGROUND: Proximal femur fractures are the second most prevalent fractures in patients older than 65 years. Despite large improvements in implant design and surgical technique, complications in fracture healing are very common. Deep infection after osteosynthetic treatment is considered to be one of the major complications with a high rate of mortality. Little is known about the adequate treatment and results in patients with infection of proximal femur fractures. The aim of this study was to evaluate the different treatment options for eradication of infection as well as to analyse the clinical outcome and quality of life. PATIENTS AND METHODS: 40 patients treated for infected proximal femur fractures between 2001 and 2010 were retrospectively analysed. Quality of life was assessed in 21 patients after an average of 40 months using the WOMAC and the SF-12 score. RESULTS: Surgical treatment included complete removal of infected implants and radical debridement. In 20 patients resection arthroplasty had to be performed. Ten patients were treated with a modular prosthesis, 4 patients were treated with a proximal femur replacement. Due to severe infection and risk-increasing comorbidities, resection arthroplasty had to be performed in the remaining 12 patients. Re-osteosynthesis could be performed in 13 patients. Average time of treatment was 67 days. At the time of follow-up the rate of mortality proved to be 15%. The rate of reinfection was 14.6%. At the time of follow-up infection was still prevalent in 2 patients. Dislocation after the hip prosthesis occurred in 3 of 14 patients. Of the 13 patients who received re-osteosynthesis one patient suffered a reinfection. Delayed fracture healing was treated with spongiosa grafts in 2 cases. 33% of the patients with resection arthroplasty died during follow-up. Statistical analysis showed better results in WOMAC and SF-12 scores in patients with hip prosthesis. Patients with re-osteosynthesis showed a larger variation in results. CONCLUSION: Deep infection after osteosynthetic treatment of proximal femur fractures is a severe complication. Radical surgical treatment and adequate local and systemic antibiotic application can help clear an infection. Quality of life is significantly reduced. Treatment should therefore be adapted to the individual patient's condition.

[Osteomyelitis of the costae caused by salmonella]. / Osteomyelitis der Rippen durch Salmonellen.

Salmonella enterica serotype Enteritidis was detected in a 34-year-old, previously healthy patient who suffered from osteomyelitis of the costae. Radical surgical debridement and antibiotic therapy were able to stop the infection. An abdominal flap and a thoracic flap were used to cover the soft tissue defect.