Post-arthroscopic septic arthritis of the knee. Analysis of the outcome after treatment in a case series and systematic literature review

OBJECTIVE

The aim of this study was to review the characteristics of patients with septic arthritis after ACL reconstruction comparing our results with those deriving from the literature review.

PATIENTS AND METHODS

Patients with suspected post arthroscopic septic arthritis of the knee occurring within 6 months after surgery were evaluated to be included in the investigation. Septic arthritis was defined by i) clinical evidence; ii) laboratory investigations; iii) synovial fluid leukocyte count of more than 2,5 x 104/μL or positive cultures obtained by synovial fluid aspirate.

RESULTS

Thirty-nine patients (median age 25 years, range 17-42) with septic arthritis following ACL reconstruction were enrolled. Staphylococci were the main bacteria identified. Resolution within 4 weeks of local signs was observed more frequently in those receiving arthroscopic debridement and synovectomy coupled with antibiotic therapy (18/21 vs. 9/18, p<0.05). Fever was present in 33 (85%) cases. Fever disappearance and CRP normalization within 4 weeks were reported more frequently in patients receiving intravenous antibiotics (17/20 vs. 9/19, p<0.05). Similar findings were retrieved by literature analysis.

CONCLUSIONS

An intravenous antibiotic therapy with surgical debridement is the first-line treatment for septic arthritis. Staphylococci are the main causative agents, justifying an empiric therapeutic approach with an anti-MRSA agent and cephalosporin.

Clinical and prognostic features of prosthetic joint infections caused by Enterococcus spp

OBJECTIVE

Pathogens colonizing the intestinal or urinary tract such as enterococci or Gram-negative bacilli can cause prosthetic joint infection (PJI).

PATIENTS AND METHODS

PJI undergoing 2-stage exchange, referred to the Department of Infectious Diseases of the Cotugno Hospital of Naples and the Fondazione Policlinico Gemelli of Rome over a 7-year period (2009-2015) for Infectious Diseases (ID) consultation were included. Demographic data, detailed information about previous or underlying diseases, findings of the clinical examination, and results of laboratory investigations were analyzed. The cure was defined by the disappearance of clinical, laboratory, and radiological evidence of PJI 96 week after the discontinuation of antibiotic treatment.

RESULTS

Thirty-one cases of PJI sustained by Enterococci were included (16 early infections, 13 delayed infections, and 2 late infections). Median age was 73 years (range 39-83), 39% were males. Comorbidities related to an increased risk of infection were reported in 17 (55%) cases. Joint pain interfering with daily living was reported in 27 (87%) cases, fever in 7 with early infection and in no case with delayed or late infection (7/17 vs. 0/14, Odds ratio undefined, p=0.01). Local inflammation and joint effusion were reported in 29 (93%) cases, sinus tract in 25 (81%). Enterococcus faecalis was the etiologic agent in 28 (90%) cases, E. faecium in 2 (6%), E. casseliflavus in 1 (3%). Eleven cases were polymicrobial. Favourable outcome was reported in 20 (65%) cases. Patients with comorbidities reported more frequently an unfavourable outcome (9/17 vs. 2/14, Odds ratio 6.7, 95% CI 1.1-39.8; p=0.06).

CONCLUSIONS

Comorbidities should arise the suspect of infection by enterococci. Associative protocols, considering drugs active against biofilm should be considered in the cases with enterococcal infection.

RELEASE OF GENTAMICIN FROM CEMENT SPACERS IN TWO-STAGE PROCEDURES FOR HIP AND KNEE PROSTHETIC INFECTION: AN IN VIVO PHARMACOKINETIC STUDY WITH CLINICAL FOLLOW-UP

Eighteen patients undergoing two-stage exchange arthroplasty for infected total hip or knee arthroplasty using gentamicin-loaded bone cement spacers (80g bone cement, 2 g gentamicin and 2 g clindamycin) were studied. The concentration of gentamicin eluted from the spacers was assessed on samples of blood, urine, and drainage fluid that were collected from each patient at set intervals during the 48 hours following the first-stage surgery. The hip and knee cement spacers showed similar curve of release over the first postoperative hours (early peak followed by slow release), but the mean gentamicin concentration in the drainage fluid was higher in patients with hip spacers compared to patients with knee spacers (30.61±19.47 mg/L vs 17.43±13,63 mg/L, p less than 0.05). In patients with hip spacers, the mean, maximum, and minimum concentration of gentamicin was higher with respect to the minimum inhibitory concentration (MIC) break point for Staphylococcus spp, Pseudomonas Aeruginosa and Enterobacteriaceae throughout the first postoperative 48 h. Conversely, in 25% of patients with a knee spacer a drug concentration below the MIC break point for Gram negative bacteria was found in the drainage fluid after 12 h. Gentamicin levels in the blood samples were negligible over the entire time interval and were steadily well below the renal toxicity reference. The highest urinary concentration of gentamicin was observed between 4 and 9 h postoperatively. Subsequently, it gradually declined until 48 h. Clinically, the rate of cure was 100% at a mean follow-up of 113 weeks (range 90-182). Gentamicin-loaded cement spacers offer the advantage of achieving early high concentrations of the antibiotic directly at the site of infection but especially in the knee a systemic antibiotic therapy must be given as a complement to the spacer implantation to eradicate periprosthetic joint infection (PJI).

Factors related to outcome of early and delayed prosthetic joint infections

In this prospective study, we evaluate the impact of adherence to a diagnostic and therapeutic protocol on prosthetic joint infections (PJI) diagnostic accuracy and outcome.

PATIENTS AND METHODS

Patients with early or delayed PJI referred over a 5-year period were included. Diagnosis was based on characteristic clinical signs, radiographic findings and microbiological evidence. Antibiotics were chosen on the basis of microbiological findings, and drugs active against methicillin-resistant staphylococci were administered if no microbiological evidence had been obtained.

RESULTS

Inclusion criteria were met in 159 cases (median age 64 years, males 45%). 56 were early infections and 103 delayed infections. Comorbidities were reported in 99 (62%) cases. Positive cultures were obtained in 122/159 (77%), coagulase-negative staphylococci were cultured in 20%, Staphylococcus aureus in 28%, and Pseudomonas aeruginosa in 7%. In early infections, cure rate after debridement and antibiotic therapy was 80%. In delayed infections, cure rate after two-stage exchange was 85%. Of 28 patients with delayed infection treated with antibiotics without surgery, only 8 (29%) infections were suppressed 48 weeks after treatment discontinuation. Rifampin afforded a better outcome.

CONCLUSION

Appropriate diagnostic and surgical procedures and microbiologically driven antibiotic therapy including rifampin are recommended to improve diagnostic accuracy and outcome.

Combined treatment with ceftriaxone and linezolid of pneumococcal meningitis: a case series including penicillin-resistant strains

This study evaluated the role of linezolid in the treatment of patients suffering from pneumococcal meningitis. Treatment included ceftriaxone (4000 mg every 24 h), linezolid (600 mg every 12 h) and dexamethasone (8 mg every 6 h). Linezolid was withdrawn if a penicillin-susceptible isolate of Streptococcus pneumoniae was identified. Of 16 patients studied, seven were infected with penicillin-non-susceptible isolates of S. pneumoniae, two died, and three reported sequelae. No toxicity was reported. It was concluded that linezolid can be used for the treatment of pneumococcal meningitis, as an alternative to vancomycin or rifampicin, in regimens including a third-generation cephalosporin.

Factors influencing the presentation and outcome of tuberculous meningitis in childhood

Tuberculosis (TB) is an important cause of morbidity and mortality worldwide. Here, we describe our experience of childhood tuberculous meningitis (TBM), focusing on factors influencing presentation and outcome.

PATIENTS AND METHODS

Children aged 0-14 years, with diagnosis of TBM and 24 months of post-therapy follow-up, were evaluated in this retrospective study.

RESULTS

Thirty-two patients with TBM were identified. Fever, nuchal rigidity and vomiting were the main presenting symptoms. Fourteen cases (44%) presented with cranial nerve palsy. Seventeen (53%) patients were in advanced stage of the disease on admission. Cerebrospinal fluid (CSF) examinations showed low glucose, high proteins and pleocytosis. A central nervous system device was placed in 4 cases (13%) because of worsening hydrocephalus. Four (13%) patients died, while 6 (19%) had sequelae. Faster normalization of CSF parameters was associated with better outcome.

CONCLUSION

Early antimycobacterial therapy and close monitoring of TBM in childhood improve the outcome.

Pulmonary aspergillosis with possible cerebral involvement in a previously healthy pregnant woman

Invasive aspergillosis is observed mainly in immunodepressed patients. Here we report a case of pulmonary aspergillosis with CNS involvement in a pregnant woman without other known causes of immunodeficiency.

CASE REPORT

A 23-years old pregnant woman underwent a caesarean because of unexplained seizures. During the subsequent days worsening headache and a deteriorating neurological status were reported suggesting meningitis. Stiffness, right sided hemiparesis and cranial nerve palsies were observed at admission. Radiological findings revealed lesions involving the right pulmonary apex, the right cerebellar hemisphere and the Pterygopalatina fossa. Microbiological studies revealed large colonies of Aspergillus fumigatus. A favorable outcome was observed after administration of liposomal amphotericin B and 5-fluorocytosine and, at improved conditions, when oral uptake of itraconazole was given. The authors conclude that risk of infections sustained by fungal opportunistic agents during pregnancy must be considered. Sequential antifungal administration may be an efficient therapy able to shorten hospitalization.

[Saquinavir + Zidovudine + Lamivudine in HIV positive naive or not naive patients]

The aim of the study was to assess the virological/immunological outcome and safety of Saquinavir (SQV), Zidovudine (AZT) and Lamivudine (3TC) therapy in HIV patients. We retrospectively evaluated the charts of 36 HIV patients (male 87% median age 31 yrs, IVDA 72%) who underwent therapy with 5QV (1800 mg/die), AZT (500 mg/die) and 3TC (300 mg/die). 26 (72%) patients were previously on antiviral therapy for at least 16 weeks. No patient ranked in the CDC group. Patients were treated for at least 48 weeks. Hematological indices, changes in CD4+ cell count and plasma HIV-RNA levels were evaluated every 30, 60, and 90 days respectively. At baseline, CD4 cell count and viral load were 230/mcl and 4.55 log respectively for patients previously on therapy and 382/ l and 4.88 log respectively for naive patients. At week 48 the mean CD4+ cell count increase was 70/ l among previously treated and 98/mcl among untreated patients. In respect to the baseline, lower mean HIV-RNA levels were observed at week 12, 24 and 48. No patient showed AIDS-defining events. No patient discontinued therapy due to suspected toxicity. Patients showed a good immunological and virological response, regardless of their previous antiviral treatment. The terapy regimen was safe and well tolerated

[Tuberculous meningitis in childhood: review of cases observed in the years 1995-1999]

In this study we reviewed M. tuberculosis meningitis (TBM) cases in childhood at our unit in a five-year period.

METHODS

Included in this retrospective study were children admitted to Cotugno Hospital from 1995 to 1999 who fulfilled criteria for a TBM diagnosis. Medical records were analyzed for epidemiological data, clinical manifestations, laboratory test results, radiological investigations and clinical outcome.

RESULTS

We identified 10 children with TBM. Family history of tuberculosis (TB) was observed in 6 patients. Fever preceded hospital admission of 4-60 days (median 8 days); neurological signs were present 1-6 days before admission in 8 patients. All patients showed a predominance of lymphocytes, elevated proteins and reduced glucose concentration in cerebrospinal fluid (CSF). Mycobacterium tuberculosis was either cultured or identified by acid fast stain in 5 patients. Cranial CT-scans and MRI showed hydrocephalus in 8 patients and ring-enhancing lesions in 6. Antituberculous therapy was administered according to current recommendations for at least 12 months, with a 4-6 week steroid therapy course. Two patients had permanent neurological sequelae.

CONCLUSIONS

Careful evaluation of symptoms and CSF findings is the only way to establish an early diagnosis and reduce sequelae.

[Hepatic encephalopathy. Pathogenesis and therapy]

Hepatic encephalopathy is a frequent complication of cirrhosis. Portal-systemic shunts and depression of hepatic function are the primary underlying abnormalities. Arterial blood ammonia levels are frequently elevated during hepatic encephalopathy and are lower when a clinical improvement is established. Glutamine synthesis is part of the metabolic pathway for ammonia cerebral detoxification that induces ATP and glutamate (excitatory neurotransmitter) depletion. Plasma levels of branched chain amino acids are reduced in patients with cirrhosis, this event allows aromatic amino acids to cross the hemato-liquoral barrier through exchange with glutamine. Cerebral excess of aromatic amino acids promotes the synthesis of octopamine and feniletiletanolamine, weak neurotransmitters. Benzodiazepine-like substances may affect GABA-ergic transmission by interacting with their receptors on the GABA-benzodiazepine complex. Therapy is aimed at controlling the events that may precipitate the acute encephalopathy, at reducing the ammonia levels, and correcting the neurotransmission abnormalities.

[Acute and chronic viral hepatitis in HIV positive patients]

In this study we evaluated the spreading of HBV, HCV, HDV and HIV among drug user patients. Spreading of hepatotropic viruses resulted high (HBV 84%, HCV 87%, HDV 7%), while spreading of HIV resulted relatively low (18%). During the period considered we did not observe any favourable effect of hepatotropic viruses on the progression of HIV infection, while the chronic evolution of acute viral hepatitis HBV related was high (90%) in HIV+ patients. HIV infection did not determine different histological findings in respect to HIV- patients with chronic hepatitis, HBV or HCV related

Typhoid fever in the Neapolitan area: a case-control study

Typhoid fever is endemic in the Neapolitan area, where its yearly incidence rate largely exceeds the corresponding national figure. During the period from January to June, 1990, a matched case-control study was carried out in order to identify risk factors of the disease in this area; 51 subjects (mean age 27.2 years) with typhoid fever were compared with 102 controls matched with respect to age, sex and educational level. Consumption of raw shellfish was reported by 76.5% of the cases, as opposed to 19.6% of the controls (P < 0.01). Subjects who had eaten this food item had a 13.3-fold risk (C.I. 95% = 5.5 - 32.8) of contracting typhoid fever. In contrast, no risk was found to be associated with consumption of cooked shellfish, raw vegetables, ice-cream, non-potable water, or unpasteurized milk. The risk factor identified in this study shows that hazardous dietary habits and inadequate sewage treatment facilities, combined with lack of sanitation in the harvesting and marketing of shellfish, play a major role in the endemicity of typhoid fever in the Neapolitan area.