Guidelines for the use of preoperative blood tests for elective surgery were established. However, there is less evidence and no guidelines regarding using these tests when a young, healthy patient undergoes minor orthopaedic trauma surgery. Bloodwork is often ordered routinely, regardless of medical history or the nature of the injury. We hypothesized that unnecessary blood work is requested for younger pre-operative patients, and their results will not change peri-operative management. This practice is not a judicious use of healthcare resources. This study aimed to evaluate the frequency, type, cost, and impact on clinical decisions if standard preoperative bloodwork was completed in healthy patients requiring surgical management of a minor fracture or dislocation. After the approval of our institutional ethics board, a retrospective chart review was conducted. Inclusion criteria were patients aged 18-60 years, who had an isolated minor orthopaedic trauma requiring outpatient surgery, who were American Society of Anesthesiologists (ASA) class 1. ASA class 1 is defined as “a normal healthy patient, without any clinically important comorbidity and without a clinically significant past/present medical history.” Data records from January 1, 2016, to December 31, 2018, were extracted from a provincial database (the Analytics Data Integration, Measurement and Reporting) for five hospitals. Data including demographics, surgical treatment, type and number of blood tests ordered, and ordering physician were collected. Any abnormal test results were checked to see whether they led to a change in patient management or related to a postoperative adverse event. Independent samples t-tests and Chi-square tests were used to compare the characteristics of patients who had preoperative bloodwork versus those who did not. The cost of preoperative blood work was estimated. During these two years, 627 patients met inclusion criteria, and 27% (n=168) of these patients had bloodwork completed pre-operatively, while only 34% (n=57) of these had one or more abnormal laboratory parameters. These abnormalities were minor and did not alter clinical management or result in repeated bloodwork peri-operatively. Patients who had bloodwork were significantly older (40.2 years) compared with patients without preoperative blood work (37.8 years; p=0.03), but there was no difference in sex between those who had bloodwork (53.4% male) and those who did not (51.4% male; p=0.63). The most common blood test ordered was a complete blood count, and the most commonly abnormal result was a mildly elevated white blood cell count (19%; n= 29). The most common patients to receive bloodwork were those with ankle (34%) and distal radius (34%) fractures. The bloodwork was primarily ordered by clinical associates (26%; n=46) and emergency department physicians (22%; n=38). Without considering lab personnel, consumables, and analysis time, the cost of this bloodwork was approximately $7685, an average of $45 per patient. Pre-operative bloodwork in young, healthy, asymptomatic patients requiring outpatient surgery for minor orthopaedic trauma had no clinical significance and did not change patient management. Rigorous prospective research is warranted to establish national guidelines for appropriate pre-operative bloodwork ordering to minimize unnecessary and costly investigations

Aim. The diagnosis of septic arthritis mostly relies on clinical examination, several blood parameters including white blood cell count, C-reactive protein, sedimentation, and the analysis of the joint aspiration. However, the diagnosis can be difficult when the symptoms are vague and the information obtained from laboratory might be insufficient for definitive diagnosis. This study aimed to evaluate several ratios obtained from routine blood tests for a possible use in the diagnosis of septic arthritis. Method. The adult patients who were operated in our clinic due to septic arthritis between 2014–2020 were identified and retrospectively evaluated. The patients with any blood disorders or missing file information were excluded. A total of 36 patients were found to be eligible for inclusion. The control group included 40 patients without any sign of infection who underwent total knee arthroplasty due to knee osteoarthritis. Preoperative blood tests of each patients were examined. In addition to CRP and sedimentation values, neutrophil-lymphocyte, monocyte-lymphocyte, platelet-lymphocyte, and platelet count-mean platelet volume were calculated and receiving operating characteristics (ROC) curve analysis was made to determine the sensitivity, specificity and area under curve (AUC) values of these parameters. Results. The distribution of affected joint in septic arthritis group was as follow; 22 knees, 6 hips, 4 shoulders, 2 elbows, 1 wrist and 1 ankle. The cultures of joint aspiration yielded positive result in 19 patients while the cultures were negative in 17 patients. All of the analyzed parameters were significantly different between the groups (p<0.001). ROC curve analysis results are given in detail, in Table 1 and Figure 1. The AUC value was 97.3 when only CRP and sedimentation values were used but increased to 98.6 when neutrophile/ lymphocyte ratio was added and increased to 100 when all analyzed parameters were included. Conclusions. The analyzed parameters were found to increase the overall sensitivity and specificity when used together with acute phase reactants. However, when evaluated separately, CRP and sedimentation were still found as the most valuable parameters in the diagnosis of septic arthritis. In the diagnosis of septic arthritis, 35 mm/hr cut-off value for sedimentation and 10 mg/L cut-off value for CRP were found more sensitive and specific compared to standard laboratory cut-off values of 20 mm/hr and 5 mg/L. For any tables or figures, please contact the authors directly

Aim. Although established serum inflammatory biomarkers, such as serum C-reactive protein (CRP) and serum white blood cell count (WBC), showed low accuracies in the literature, they are still commonly used in diagnosing periprosthetic joint infections (PJI). For a sufficient preoperative diagnosis novel more accurate serum parameters are needed. The aim of our study was to evaluate the performances of the established and novel routinely available serum parameters in diagnosing periprosthetic joint infections when using the proposed European Bone and Joint Infection Society (pEBJIS) criteria. Method. In this retrospective study, 177 patients with an indicated revision surgery after a total joint replacement were included from 2015 to 2019. The easily accessible and routinely available serum parameters CRP, WBC, the percentage of neutrophils (%N), the neutrophils to lymphocytes ratio (NLR), fibrinogen and the platelet count to mean platelet volume ratio (PC/mPV) were evaluated preoperatively. The performances were examined via receiver operating characteristic (ROC) curve analysis (AUC). The curves were compared using the z-test. Seventy-five cases (42%) showed a PJI based on the pEBJIS-criteria. Results. The sensitivities of serum CRP (cut-off: ≥10mg/L), WBC (≥10×10^9 cells/L), %N (≥69.3%), NLR(≥ 3.82), fibrinogen (≥ 457 mg/dL), and PC/mPV (≥ 29.4) were calculated with 68% (95% CI: 57–78), 36% (26 – 47), 66% (54 – 76), 63% (51 – 73), 69% (57 – 78), and 43% (32 – 54), respectively. Specificities were 87% (79 – 93), 89% (81 – 94), 67% (57 76), 73% (63 – 81), 89% (80 – 93), and 81% (72 – 88), respectively. Serum CRP and fibrinogen showed better performances than the other evaluated serum parameters (p<0.0001). The median serum CRP (17.6 mg/L) in patients with PJI caused by a low virulence microorganism was lower compared with infections caused by high virulence organisms (49.2 mg/L; p=0.044). Synovial fluid leucocyte count and histology showed better accuracies than serum CRP, serum WBC, %N, NLR, serum fibrinogen, and PC/mPV (p<0.0001). Conclusions. Although serum CRP and fibrinogen showed the best performances among the evaluated serum inflammatory markers, their results should be interpreted with caution in clinical practice. Serum parameters may remain normal in chronic infections or may be elevated in patients with other inflammatory conditions. In addition, they also correlated poorly with synovial fluid leukocyte count and histology. Therefore, serum parameters are still insufficient to confirm or exclude a periprosthetic joint infection. Hence, they can only be recommended as suggestive criteria in diagnosing PJI

Aim. The aim of this study was to compare outcomes between patients with diabetic foot soft-tissue infection and osteomyelitis. Methods. Medical records of patients with diabetic foot infection involving either soft-tissue (STI) or bone (OM) were retrospectively reviewed. Diagnosis was determined by bone culture, bone histopathology or imaging with magnetic resonance imaging (MRI) or single-photon emission computed tomography (SPECT/CT). Patient outcomes were recorded up to 1 year after admission. Results. Out of 294 patients included in the study, 137 were diagnosed with STI and 157 had OM. No differences in age (p=.40), sex (p=.79), race (p=.83), body-mass index (p=.79) or type of diabetes (p=.77) were appreciated between groups. Frequency of comorbidities (neuropathy, chronic kidney disease, peripheral arterial disease) also did not differ except for increased prevalence of cardiac disease in patients with STI (86.9%) compared to those with OM (31.8%) (p<.00001) and decreased prevalence of retinopathy (24.8% vs. 35.7%) (p=.04). Patients with OM had greater C-reactive protein (p<.00001), erythrocyte sedimentation rate (p<.00001) and white blood cell count (p<.00001). Among 1-year outcomes, patients with OM more often underwent surgery (p<.00001), had lower limb amputations (p<.00001), became reinfected (p=.0007), were readmitted for the initial problem (p=.008), had longer time to healing (p=.03) and had longer hospital length of stay (p=.00002). However, no differences in 1-year mortality (p=1.000), overall 1-year readmission (p=.06) or healing within 1-year (p=.64) were appreciated. Conclusion. In our study, OM was associated with more aggressive treatment, reinfection and longer time to healing than STI. However, despite being associated with more aggressive care and readmissions, patients with diabetic foot OM has similar 1-year mortality and healing rates to those with diabetic foot STI

Background. Preoperative diagnosis of fracture related infections can be challenging, especially when confirmatory criteria such as sinus tract and purulent discharge are absent. Although serum parameters, such as CRP and white blood cell count (WBC), showed poor accuracy in the literature, they are still often used in clinical practice. The European Bone and Joint Infection Society (EBJIS) defined evidence-based criteria for fracture related infection. Elevated serum inflammatory markers were regarded as suggestive criteria only, as the literature was of limited quality. This study assessed the diagnostic value of the serum parameters CRP, WBC and differential cell count in the diagnosis of fracture related infections defined by the EBJIS-criteria for fracture related infections. Methods. In this retrospective cohort study, 94 patients who underwent surgical treatment for suspected infected non unions after failed fracture fixation were included. Preoperatively, blood samples including serum inflammatory markers were taken. For this study, cut-offs of 5 mg/L for CRP, 10×10⁁9 cells/L for WBC, and >70% for the percentage of neutrophils were regarded as positive for infection. All patients had intraoperative samples taken for microbiology and histology. Analysis of diagnostic accuracy was based on the receiver-operating characteristic (ROC). Results. Based on the EBJIS criteria, 40 patients (43%) were diagnosed with a fracture related infection. 11/94 (12%) patients had an elevated serum WBC count, 13/94 (14%) an increased percentage of neutrophils, and 43/82 (52%) an elevated serum CRP. The mean values of CRP concentration, WBC count, and percentage of neutrophils in the infection group were 7.9 mg/L (IQR:6.4 – 9.7), 18.3 G/l (IQR: 3.9 – 24.9), and 63% (IQR: 58 – 67%), respectively. The sensitivity, specificity, and area under the curve of serum WBC count were 20% (95% CI: 10 −35%), 94.4% (84 −99%), and 0.57 (0.50 – 0.64), respectively; of percentage of neutrophils 12.5% (5 – 27%), 85.2% (73 −93%), and 0.49 (0.42 – 0.56); and of serum CRP 67.6% (51 – 90%), 60.0% (45 – 73%), and 0.64 (0.53 – 0.74), respectively. A statistically significant difference between the AUCs of all three serum parameters and AUC of tissue culture as well as AUC of histology was shown (p <0.0001). A simple decision tree approach using only low WBC and CRP may allow identification of aseptic cases. Conclusion. Based on the standardized and evidence-based EBJIS criteria, the three inflammatory serum markers showed an insufficient accuracy for the diagnosis of fracture related infections. They also correlate poorly with culture or histological diagnosis. Therefore, they should not be used alone as a confirmatory test

Purpose. Various approaches have been reported for the total hip replacement (THR). In recent years, a muscle sparing approach with low postoperative muscle weakness and low dislocation risk has been frequently selected. However, such surgery has a learning curve. Thus, at the time of switching from the conventional approach to such approaches, invasion or infection risk may increase with the operation time extension. The purpose of this study is to clarify the change of invasiveness or latent infection rate with the change in approach in order to select the cases safely at the beginning of introducing a new approach in THR. Methods. In facility A, THR was performed with Dall's approach (Dall), but 1 surgeon changed Dall to anterolateral modified Watson-Jones approach (OCM) and another surgeon changed Dall to direct anterior approach (DAA). In facility B, all 3 surgeons changed posterolateral (PL) approach to OCM. The subjects are 150 cases in total, including the each last 25 cases operated with the conventional approach and the each first 25 cases operated with a new approach (Dall to OCM: 25 + 25, Dall to DAA: 25 + 25, PL to OCM: 25 +25 cases). And, differences in operative time, intraoperative bleeding volume, postoperative hospital stay, and postoperative hemoglobin, white blood cell count, lymphocyte count, creatine kinase (CK), C-reactive protein (CRP) were investigated. Results. The average age of subjects was 64 years (31–87 years old), and there were 27 male subjects and 123 female subjects. In the change from Dall to OCM, only the postoperative hospital stay decreased significantly. In the change from Dall to DAA, the length of hospital stay and postoperative CRP significantly decreased, but the intraoperative bleeding volume increased. In the change from PL to OCM, the operation time, postoperative CRP and CK decreased, but postoperative Hb decreased. Cases with lymphocytes less than 1000/µL or less than 10% after surgery on day 4 are latent infection cases, and in such cases the operation time was significantly longer, the postoperative Hb was significantly lower, and the postoperative CK was significantly higher. However, such cases were not significantly increased by the change of operation approach. Conclusion. Introduction of the muscle sparing approach improved many items on surgical invasion, but some items deteriorated especially at the beginning of a new approach. In the early stages of introduction of the new approach, choosing cases without obesity and without lots of muscle volume may reduce latent infection

While advances in laboratory and imaging modalities facilitate the diagnosis of periprosthetic joint infection (PJI), clinical suspicion and a thorough history and physical remain the basis of evaluation. If clinical suspicion is high, the evaluation should be more vigorous, and vice versa. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are inexpensive as well as ubiquitous, and should be obtained as a preliminary screening tool. These tests have been found to be cost-effective and highly sensitive. If both tests are negative, there is a low risk of periprosthetic joint infection (i.e., good negative predictive value). Positive results on both tests, in contrast, are not as specific but again raise suspicion. When either the ESR or CRP is elevated, or if the clinical suspicion for infection is high, aspiration of the knee joint is suggested. Synovial fluid should be sent for a synovial fluid white blood cell count (WBC), differential and culture. Given the ability to get three data points from one intervention, arthrocentesis, is the best single maneuver the physician can perform to rule in or out PJI. The synovial fluid WBC count has demonstrated in multiple studies excellent specificity and sensitivity in the diagnosis of infection. Based on multiple recent studies, the proceedings of the International Consensus on PJI recommend cut-offs for the synovial fluid WBC count as >3000 cells/mL and > 80% neutrophils for the differential. Synovial fluid biomarkers represent an expanding area of clinical interests based on the unique cascade of gene expression that occurs in white blood cells in response to pathogens. Deirmegian et al. described the unique gene expression and biomarker production by neutrophils in response to bacteria that are detectable in synovial fluid. Specifically, alpha-defensin is one such antimicrobial peptide. Along with synovial CRP, alpha-defensin can be measured in a currently commercially-available immunoassays. The diagnosis of PJI can be difficult to make in spite of the variety of tests available. That being said, the diagnosis is easily made in our experience in 90% of patients by getting an ESR and CRP followed by selective aspiration of the joint if these values are elevated or if the clinical suspicion is high. Synovial fluid obtained should be sent for a synovial fluid WBC count, differential and cultures

Aim. Open fractures still have a high risk for fracture-related Infection (FRI). The optimal duration of perioperative antibiotic prophylaxis (PAP) for open fractures remains controversial due to heterogeneous guidelines and highly variable prophylactic regimens in clinical practice. In order to provide further evidence with which to support the selection of antibiotic duration for open fracture care, we performed a preclinical evaluation in a contaminated rabbit fracture model. Method. A complete humeral osteotomy in 18 rabbits was fixed with a 7-hole-LCP and inoculated with Staphylococcus aureus (2×106 colony forming units, CFU per inoculum). This inoculum was previously shown to result in a 100% infection rate in the absence of any antibiotic prophylaxis. Cefuroxime was administered intravenously in a weight adjusted dosage equivalent to human medicine (18.75 mg/kg) as a single shot only, for 24 hours (every 8 hours) and for 72 hours (every 8 hours) in separate groups of rabbits (n=6 per group). Infection rate per group was assessed after two weeks by quantitative bacteriological evaluation of soft tissue, bone and implants. Blood samples were taken from rabbits preoperatively and on days 3, 7 and 14 after surgery to measure white blood cell count (WBC) and C-reactive protein (CRP) levels. Results. Duration of PAP had a significant impact on the success of antibiotic prophylaxis. The single shot regimen completely failed to prevent infection. All samples (soft tissue, implant and bone) from this group displayed high numbers of bacteria. Additionally, abscesses were present in two of six rabbits. The 24-hour regimen showed a reduced infection rate (1 out of 6 rabbits infected), but only the 72-hour course was able to prevent FRI in all animals in our model. After an initial postoperative peak on day three, CRP levels then decreased to baseline (approx. 30 µg/ml) in the 24h-group and 72h-group, but remained significantly higher in the single shot group at day 7 and 14 (p<0.05). Conclusions. When contamination with high bacterial loads is likely (e.g. in an open fracture situation), a 72-hour course of intravenous cefuroxime appears to be superior in preventing FRI compared to a single shot or 24-hour antibiotic regimen. Acknowledgements. This work was funded by AOTrauma

To report a rare case of successfully treated synchronous shoulder septic arthritis, total knee replacement infection and lumbar spondylodiscitis in a patient with rheumatoid arthritis. Fifty-six year old woman, with a history of rheumatoid arthritis diagnosed at twenty-five year old, and total knee replacement at fifty-four. Recently treated with etanercept, presented with acute inflammatory signs of the right shoulder in addition to right knee and lumbar back pain for 6 months. After a shoulder and knee arthrocentesis the diagnosis suspicion of shoulder septic arthritis and total knee replacement infection was confirmed. Therefore it was performed shoulder arthroscopic irrigation and debridement and the first of two stages knee revision, with implantation of antibiotic cement on cement articulating spacer. It was also diagnosed a L1–L2 and L4–L5 spondylodiscitis with dural compression documented on MRI, which determined surgical treatment. By a posterior approach it was performed instrumentation from T11 to L5, followed by L1–L2 and L4–L5 discectomy and interbody fusion with autograft. Shoulder and knee synovial fluid cultures where positive for Methicillin Sensible Staphylococcus aureus narrowing the broad-spectrum combination therapy to levofloxacin for six weeks, with symptomatic relieve and C-reactive protein and white blood cell count returning to normal values. Almost one year down the line the patient remained with no sign of infection, even under the influence of immunosuppressive therapeutic. She returned to her previous status concerning the rheumatologic disease and the second stage knee revision is being planned to happen on the short run. Rheumatoid arthritis patients are a high-risk group for septic arthritis considering, among others, the immunosuppressive therapeutics and the frequent history of arthroplasty. The presented case illustrates three different type of septic complication in the same patient. The timely and aggressive approach was the key factor for a good outcome

The aim of this study was to assess the incidence of low-grade infections in total hip arthroplasty revisions and the clinical outcomes after two-time revision surgery. Retrospective study of total hip arthroplasty revision surgery between January of 2012 and December of 2013. Inclusion criteria: two-time revision surgery, PCR (pre and post-op) white blood cells count and microbiological culture. The diagnosis of low-grade infection was based on the Academy of Orthopedic Surgeons’ (AAOS) guidelines. All patients were evaluated with the Harris Hip Score (HHS). Between this period were revised a total of 79 hips, none of them bilateral, of these fourteen full-filled the inclusion criteria, eight women and six men. The mean time between primary arthroplasty and revision surgery was 4.5 years. The interface was metal-on-polyethilene in thirteen and metal-on-metal in one. All patients had at least three episodes at the urgency department with permanent hip pain in the last six months. Ten have done a course of antibiotics previous to surgery. Intra-articular pus was present in four patients. The agent isolated was S. Aureus in five and S. Epidermidis in two. An elevated PCR and leucocytosis was present in all patients. The mean PCR was 18.1 and leucocytes countage 7600. The HHS was good in four patients, fair in seven patients and poor in three. These three patients with poor had another surgical intervention due to recurrent dislocation. Periprosthetic joint infection is a common complication after total hip arthroplasty (THA). The incidence is approximately 1% after primary replacement and about 4% revision arthroplasty. As stated by Hanssen successful treatment outcomes require precise assessment of the infecting organism, the immune status of the patient, and the condition of the bone and soft tissues around the joint. With this study we tried to establish a protocol in our service: patient with a THA, interface metal-on-polyethilene, persistent coxalgia and elevated PCR will be diagnosed with low-grade infection, however we need further revision of our experience

Diagnosis of chronic prosthetic joint infection (PJI) is often challenging. Painful prosthesis is frequently due to an infection but to diagnose it is somethimes difficult. All recent guidelines stress the central role of joint punction in diagnosis of PJI if the infection is not demonstrated. However which test on synovial fluid must be carried out is not so clearly defined. Total white blood cell count and differential leukocite count are usually considered useful in diagnosis but cut offs reported by different studies are quite different. Moreover this test needs a relatively large amount of fluid and blood contamination of it largely affects the result. What's more the synovial fluid WBC count may be unreliable in the setting of a metal-on-metal bearing or corrosion reaction. Routine cultures should be maintained between 5 and 14 days, their sensitivity appears low in chronic infection even if witholding antimicrobial therapy before the collection of the fluid can increase the likelihood of recovery an organism. Synovial leukocyte esterase can be performed as a rapid office or intraoperative point of care test using urinalysis strips. It is cheap and easy to perform, but the presence of blood in the sample can affect the result and it needs centrifugation. Recently a new test has been proposed to detect alfa-defensine in synovial fluid. It shows a high sensitivity and an exellent specificity. We performed 25 joint punctions on 25 patients with suspected PJI (enrollment is going on). Synovial fluid collected was tested for: leukocite esterase, WBC count and differential, colture in blood colture bottle for anerobe and aerobes (BacT/ALERT Biomerieux, inc) and detection of alfa-defensine level (Synovasure – Zimmer). In patients who underwent surgery at least 5 samples of periprotesic tissue were collected for microbiologic analysis and the removed implant was sonicated according with the methodic. Furthermore samples for frozen section were sent and a histologic examination was made according to the Moriewitz – Kerr classification. The MSIS criteria was utilized to classify the case as infected or not

Pyogenic spondylodiscitis is an uncommon but clinically relevant infection that represents 3 to 5% of all cases or osteomyelitis. In Europe, it has an estimated incidence of 0.4 to 2.4/100.000 people/year. Mortality is less than 5%, increasing with a delay in diagnosis greater than 2 month. Patients with renal failure have greater predisposition to infections, consequence of the chronic uremic state. Infection rates in Polytetrafluoroethylene (PTFE) hemodialysis grafts in end-stage renal disease (ESRD) range from 3 to 35%. We present a rare case of concurrent spondylodiscitis and PTFE graft infection in a patient with ESRD and recurrent urinary tract infections (RUTI). The authors present a case of an 80-year-old man with past medical history significant for abdominal aortic aneurysm, bilateral ureter-hydronephrosis, Pseudomonas aeruginosa RUTI and ESRD. Three months after a dialysis PTFE graft hemoaccess was performed a Pseudomonas graft infection was diagnosed and the PTFE graft was removed. One week later, the patient was observed in the author's Department due to an insidious dorsal-lumbar mechanic back pain without neurologic deficits, with progressive deterioration over the past 6 months. A T12-L1 and L1-L2 spondylodiscitis with dural compression was diagnosed and vertebral instability was documented on MRI and TC, demanding surgical treatment. Instrumented fusion with a screw and rod construct was performed from T9 to L5, along with somatic L1 and L2 debridement, and T12-L1 interbody fusion with autograft. Microbiology results were positive for Pseudomonas aeruginosa. Antibotic therapy with ceftazidime (6 weeks) and ciprofloxacin (12 weeks) was performed. Symptomatic relieve was achieved and C-reactive protein and white blood cell count returned to normal values. No complications were documented. Four months post-surgery, the patient was asymptomatic (Visual Analogue Scale=0), with no significant limitation in his daily life activity (Disability Rating Index=85) and the vertebral body height was sustained, with imagiological signs of spinal fusion. ESRD patients are more susceptive to infections. Failure in early diagnosis and treatment may lead to disease progression and subsequent functional limitations, deformity and increase in mortality. An aggressive approach, despite delay on diagnosis, is the key factor for a worthy outcome. Despite the good results, recrudescence of spondylodiscitis is known to occur even years after the original offense is treated

Acute septic arthritis of the knee may be a challenging diagnosis in the emergency department and must always be excluded in any patient with knee pain and local or systemic signs of infection. Arthrocentesis of the suspected knee is mandatory, since the analysis of the synovial fluid gives useful information like the white blood cell count (WBC)/mm3 or the polymorphonuclear cell percentage (PMP). These parameters will help the clinician to make the decision to drain the joint in the operation room, without having to wait for the culture or Gram stain, which may take several days to be available. The classical cutoff of 50,000 WBC/mm3 with more than 90% of PMP may fail to include all the septic arthritis of the knee, since significant variation have been described in recent years. The aim of this study was to evaluate the accuracy of WBC/mm3 and PMP in the synovial fluid in the diagnosis of acute septic arthritis of the knee. We reviewed the clinical data of patients diagnosed with acute septic arthritis of the knee admitted in our center between January 2010 and December 2014, specifically the WBC/mm3 and the PMP of the synovial joint fluid. The criteria for diagnosis of an acute septic arthritis of the knee was report of purulent material when arhtrotomy or arthroscopy was performed or a positive culture of the joint fluid. The statistical evaluation of the results was performed using Student's t-test. 48 patients matched the inclusion criteria. The mean WBC/mm3 was 44.333 (14.610–182.640) and the mean PMP was 91,89% (86,4%–98,1%). 28 patients (58,33%) had a WBC/mm3 below 50.000 and 44 patients (91,67%) had a PMP above 90%, both with no statistical significance. Knee arthrocentesis is mandatory in every patient suspected to have an acute knee pyoarthrosis, since the joint fluid analysis may show several abnormal findings. Our results show that a considerable number of patients may show a relatively low WBC/mm3 in the joint fluid in the presence of a knee pyoarthrosis. The PMP may be a better criteria, but again failed to achieve statistical significance, probably because of the low number of patients. The synovial fluid analysis alone is probably misleading in the diagnosis of an acute septic arthritis of the knee if the clinician is guided by the classical guidelines. The physical examination, medical history, laboratory and imagiologic tests are all key elements in this challenging diagnosis

Chronic posttraumatic osteomyelitis (CPTO) is a complex condition that results in considerable morbidity and may be limb threatening. Tibia is the most common site of CPTO, with an average infection rate of 10% for open fractures and 1% for closed fractures. In most cases osteomyelitis is polymicrobial. Staphylococcus aureus is the most common infecting organism present either alone or in combination with other pathogens in 65 to 70% of patients. Adequate soft-tissue coverage is one of the cornerstones in chronic osteomyelitis management. Vacuum-assisted closure (VAC) is frequently used for the treatment of posttraumatic osteomyelitis of the extremities. After debridement and repeated VAC dressing changes, the wounds are closed by secondary suture, split-thickness skin grafts or local flaps. Free muscle flaps are recommended in distal third tibial defects. We present our experience with two case reports. The authors present two cases of type IIIA osteomyelitis according to Cierny-Mader classification, following previous distal third tibial open fractures. Both patients presented with limb deformity, insidious local pain and chronic purulent discharge (without significant local inflammatory signs) after 11 and 24 years of trauma. They were treated with radical debridement of all nonviable and infected tissue, VAC instillation therapy for 3 weeks and transverse rectus abdominis muscle (TRAM) flap defect coverage. Intra-operative cultures were positive for multiple pathogens. Specific antibiotic therapy was performed for each case for 8 weeks. Symptomatic relieve was achieved and C-reactive protein and white blood cell count returned to normal values. No complications were documented. 1 year post-surgery, both patients remain asymptomatic, with no signs of infection, with full flap integrity and gait without assistance. Despite the challenging management of chronic posttraumatic osteomyelitis of the tibia, infection control and a satisfactory functional outcome can be achieved. The cornerstones of management include infection control with surgical debridement, microbial-specific antibiotic administration and soft tissue coverage. VAC instillation therapy has an important role promoting granulation tissue formation and infection eradication. The aggressive approach, even with delay on diagnosis, is the key factor for a worthy outcome. Despite the good results, recrudescence of osteomyelitis is known to occur even years after the original offense is treated

INTRODUCTION. Total joint arthroplasty continues to gain acceptance as the standard of care for the treatment of severe degenerative joint disease, and is considered one of the most successful surgical interventions in the history of medicine. However, infection of these implants, called Periprosthetic Joint Infection (PJI), remains one of the biggest challenges facing orthopaedics today. PJI can lead to additional surgeries, revision, fusion and amputation. Diagnosis of PJI. It is important to accurately diagnose PJI because its management differs from that of other causes of arthroplasty failure. In acute infection, the local signs and symptoms (e.g., severe pain, swelling, erythema, and warmth at the infected joint) of inflammation are generally present. On the other hand, chronic infection usually has a more subtle presentation, with pain alone, and is often accompanied by loosening of the prosthesis at the bone-implant interface. The diagnosis of PJI has proven quite challenging, as both acute and chronic infections can be difficult to differentiate from other forms of inflammation. The reported literature on the diagnosis of PJI has focused on evaluated laboratory tests that were never developed specifically for the diagnosis of PJI. These include the erythrocyte sedimentation rate (ESR), the serum C-reactive protein (CRP), the synovial fluid white blood cell count and the leukocyte differential. Because these tests were not made for the purpose of diagnosing PJI, it has been the responsibility of the orthopaedic community to evaluate and recommend their interpretation. This has resulted in significant confusion regarding the appropriate thresholds and optimal combination of these tests. These difficulties were the motivation for the development of a specific test for the detection of PJI. The Synovasure® Test for Periprosthetic Joint Infection (PJI). The promising diagnostic capabilities of synovial fluid biomarkers for PJI have already been reported in the literature. These biomarkers include inflammatory proteins, cytokines, and microbicidal peptides / proteins that are known to be involved in the host response to infection. Studies have demonstrated that the alpha-defensin microbicidal peptide present in human neutrophils is an ideal biomarker for PJI due to the distinct separation it achieves between positive and negative results. A specific test allowing to measure the concentration of the alpha-defensin in the synovial fluid has been developed. The specificity and the sensitivity of this test for the detection of a PJI are respectively 96% and 97%. This test has been proven to have also a high reproducibility, its results not being influenced by antibiotics. DISCUSSION. A lateral flow version of this test (Synovasure PJI, distributed exclusively in Europe by Zimmer GmbH) has been recently developed. It allows reading the results in 10 minutes and it doesn't require any laboratories for its interpretation. Currently, this test device is in clinical evaluation in more than 200 European hospitals. CONCLUSIONS. In case that the clinical evaluation of this test device is positive, this method will be a new paradigm for the diagnosis of periprosthetic joint infection

Periprosthetic joint infection (PPJI) following shoulder arthroplasty is uncommon, with an overall rate of 0.98%. However, the rates following revision arthroplasty and reverse arthroplasty are much higher. Given the rapid increase in the prevalence of shoulder arthroplasty and the increasing revision burden, the cost of PPJI to society will likely increase substantially. The most common organisms found in PPJI following shoulder arthroplasty are Staphylococcus aureus, coagulase-negative Staphylococcus, and Propionibacterium acnes (P. acnes). P. acnes is especially common in males. Traditional testing for PPJI includes aspiration, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP). Aspiration often yields a dry tap and when fluid is obtained for culture, a positive result is helpful but a negative result does not rule out PPJI. Although WBC, ESR, and CRP are often positive with PPJI in the lower extremity, they are most often negative in shoulder PPJI. Although bone scans and WBC labeled scans are used, they are expensive and have low sensitivity and specificity. New testing and techniques have been reported in an attempt to improve sensitivity and specificity for PPJI. These techniques can be divided into tests on serum, synovial fluid, and tissue. Serum Interleukin-6 (IL-6) is highly specific (94%) for shoulder PPJI but has low sensitivity (14%). Synovial fluid can be tested for leukocyte esterase using a simple and cheap technique. In lower extremity PPJI it has shown to be helpful. It is not as helpful in shoulder PPJI with 30% sensitivity and 67% specificity. Alpha defensin has been reported to be more sensitive (63%) and as specific (95%) as traditional techniques but still lacks predictive value. Testing for specific cytokines (IL-2, IL-6, TNF- α) within synovial fluid is not widely used as yet but has shown promise with 80% sensitivity and 90% specificity. Obtaining tissue for culture and other testing is probably the most reliable way of confirming PPJI for the shoulder. Frozen sections taken at the time of revision can be helpful but is very pathologist dependent and institution specific. With a dedicated musculoskeletal pathologist, the finding of 10 or more WBCs per high powered field has been reported to be 72% sensitive and 100% specific for P. acnes and 63% sensitive and 100% specific for other organisms. Cultures from arthroscopic tissue biopsy have also been found to have high sensitivity (100%) and specificity (100%). Genetic testing of tissue biopsy specimens (PCR/NGS) has recently been reported and shows great promise. The significance of positive cultures and other tests, especially for P. acnes is unclear. There is a high rate of positive intra-operative cultures in primary cases of shoulder arthroplasty. In addition, intra-operative cultures taken at the time of revision, even in cases in which infection is not suspected, are frequently positive for P. acnes with weak correlation with rates of post-operative clinical infection. In conclusion, shoulder PPJI is a difficult problem to deal with. The definition of shoulder PPJI is currently unclear and further study is needed. There is no ideal test to confirm it. A reasonable approach is to aspirate for culture, and perform serum tests for WBC, ESR, and C-reactive protein. If any of these is positive in the setting of a painful arthroplasty, PPJI should be assumed until proven otherwise. Operative tissue cultures are probably the most reliable test but the clinical significance is not always obvious. Synovial fluid cytokine profiles and tissue PCR/NGS show promise for the future

Aim. One of the most accurate and inexpensive tests in detection of prosthetic joint infection (PJI) is synovial fluid white blood cell (WBC) count and differential. Since leukocytes produce many different interleukins (IL) in situation of PJI, we hypothesized that ILs could be even more accurate in detection of PJI. The aim of the study was to test, if the synovial fluid IL-6 level is superior to WBC count and differential in detection of PJI. Methods. Unselected patients undergoing total hip or knee revision surgery were prospectively included. In perioperative assessment phase, WBC count, differential and IL-6 levels of synovial fluid were measured. Patients were labelled as positive or negative according to the predefined cut-off values for IL-6 (230pg/ml) and WBC count with differential (1,7 × 10. 9. WBC/ml with ≥65% of granulocytes). During the surgery, at least 4 intraoperative samples for microbiological and one for histopathological analysis were obtained. PJI was defined as presence of sinus tract, inflammation in histopathological samples, and growth of the same microorganism in at least two or more samples of periprosthetic tissue or synovial fluid. Binary diagnostic test was performed to check the diagnostic strength of both methods in detection of PJI. Results. 49 joints of 48 patients (mean age, 71 years; 53% females) undergoing artificial hip (n = 24) or knee (n = 25) revision surgery were included. 11 joints (22%) were infected. Sensitivity of synovial fluid WBC count with differential was 82%, specificity 97%, accuracy 94%, positive and negative predictive values were 90% and 95%, respectively. Sensitivity of IL-6 level was 73%, specificity 95%, accuracy 90%, positive and negative predictive values were 80% and 92%, respectively. There was a strong statistical agreement between both tests (Kappa value=0.749) and consequently there was no significant difference in detection of PJI comparing both tests (P=0.171). Conclusion. Our study revealed that synovial fluid IL-6 level is not superior to synovial fluid WBC count with differential in detecting PJI

Background. Total knee prostheses are continually being redesigned to improve performance, longevity and closer mimic kinematics of the native knee. Despite continued improvements, all knee implants even those with proven design features, have failures. We identified a cohort of patients with isolated tibial component failures that occurred in a popular and successful knee system. Our purpose was to (1) characterize the observed radiographic failure pattern; (2) investigate the biologic response that may contribute to the failure; and (3) to determine if the failure mechanism was of a biological or a mechanical nature. Methods. Twenty-one knees from 19 patients met the inclusion criteria of having isolated tibial component failure in a commonly used knee implant system. Radiographs from the primary and revision knee surgery were analyzed for implant positioning and failure pattern, respectively. Inflammatory biomarkers IL-1β, IL-6 and TNF-α were available in 16/21 knees and peripheral CD14. +. /16. +. monocytes were measured in 10 of the above mentioned 16 knee revisions. Additionally, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were measured to rule out infection as the cause of the cytokine upregulation. Results. Radiograph findings demonstrated that all of the 21 tibial components were implanted in either neutral or 2–3° varus position, none of the revisions were implanted in valgus (figure 1). All tibias showed obvious radiographic loosening and failed into varus. The inflammatory biomarkers IL-1b, IL-6, & TNF-a were negative. WBC, ESR, CRP were normal. Peripheral CD14+/16+ and total CD16+ monocytesmeasurements were consistent with previous findings of patients with osteoarthritis (figure 2). Conclusions. The findings supported a mechanical failure mechanism rather than that of a wear debris induced inflammatory pattern. The loosening, collapse and debonding from the cement may have been related to the implantation technique, stresses due to rotational freedom of the implant, or patient characteristics/behavior. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Introduction. Perioperative dexamethasone has been shown to effectively reduce post-operative nausea and vomiting and aide in analgesia after total joint arthroplasty (TJA), however systemic glucocorticoid therapy is carries the theoretical risk of increased susceptibility to prosthetic joint infection (PJI), increased white blood cell (WBC) counts, and increased blood glucose levels. The purpose of this study is to determine the effect of dexamethasone on PJI, WBC count, and blood glucose levels in diabetic and non-diabetic patients undergoing TJA. Methods. A retrospective chart review of all patients receiving primary total joint (hip or knee) arthroplasty between January 1, 2013 and December 31, 2015 (n = 1818) was conducted. The patients were divided into two main cohorts: those receiving dexamethasone (n = 1426) and those not receiving dexamethasone (n = 392); these groups were further subdivided into diabetic (n = 428 dexamethasone; n = 129 no dexamethasone) and non-diabetic patients (n = 998 dexamethasone, n = 263 no dexamethasone). The primary outcome was PJI; secondary measures included in (WBC) count, glucose levels, and days to infection. Statistics were carried out using chi-squared or ANOVA tests. Results. Of the 1818 joints, 1.05% (19) developed PJI; there was no significant difference between the dexamethasone and no dexamethasone groups (p = 0.1023): 12 (0.84%) in the dexamethasone group and 7 (1.79%) in the no-dexamethasone group. Additionally there was no significant effect on the increase in WBC count (p = 0.1784) or on the increase in blood glucose (p = 0.3120). Further subdividing the patients, there was a significantly higher rate of infection in those who received dexamethasone with diabetes (2.1%) compared to those without diabetes (0.30%) (p = 0.0016). Further, diabetics who received dexamethasone had a significantly greater elevation in blood glucose (p < 0.0001) compared to non-diabetics, but no significant change in WBC count (p = 0.6993). Conclusion. Perioperative intravenous dexamethasone had no statistically significant effect on the overall rate of prosthetic joint infections in primary total hip or knee arthroplasty; however diabetic patients had a significantly higher rate of infection compared to non-diabetics when given dexamethasone. WBC counts were not affected overall by administration of dexamethasone, or with stratification into diabetics and non-diabetics. Glucose levels were not effected by administration of dexamethasone

Background:. Failed metal-on-metal (MOM) bearings and corrosion reactions are being increasingly encountered with little to guide evaluation for periprosthetic joint infection (PJI). Our purpose was to determine the utility of the erythrocyte sedimentation rate (ESR), C-Reactive Protein (CRP), synovial fluid white blood cell (WBC) count and differential (%PMN) in diagnosing PJI in failed hips with a MOM bearing or corrosion. Methods:. 150 revision hips (92 MOM total hip arthroplasties, 19 MOM hip resurfacings, 30 non-MOM bearings with corrosion and 9 full-thickness bearing surface wear with metallosis) were retrospectively evaluated. Nineteen patients were diagnosed as infected using MSIS criteria. Mean laboratory values were compared between groups and receiver operator characteristic curves (ROC) generated with an area under the curve (AUC) to determine test performance and optimal cutoffs. Results:. The synovial fluid WBC count was judged to be inaccurate secondary to cellular debris in 47 of the 141 patients where one was obtained (33.3%); a WBC count was still reported, however, in 35 hips, 11 of which were falsely positive. Infected patients had significantly higher mean serum ESR, CRP, synovial fluid WBC count, and differential (p < 0.0001, all). The best tests for diagnosis of PJI were the synovial fluid WBC count (AUC=98%, optimal cutoff 4350 WBC/μL), and differential (AUC = 90%, optimal cutoff 85% PMN). Diagnostic performance of the synovial fluid WBC count and differential improved with fewer false positives after excluding inaccurate samples. The ESR and CRP both had good sensitivity. Conclusions:. The diagnosis of PJI is extremely difficult in patients with MOM bearings or corrosion and the synovial fluid WBC count can frequently be falsely positive and should be relied upon only if a manual count is done and if a differential can be performed. A more aggressive approach to preoperative evaluation for PJI is recommended in these patients to allow for careful evaluation of the synovial fluid specimen, the integration of synovial fluid culture results, and repeat aspiration if necessary