ANALYSIS OF TISSUE BIOPSY AND JOINT ASPIRATION IN THE DIAGNOSIS OF PERIPROSTHETIC HIP INFECTIONS: CROSS-SECTIONAL STUDY

ABSTRACT Objective: To evaluate sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of preoperative joint aspiration (PJA) and periarticular tissue percutaneous biopsy (PTPB), as well as their combination, in the diagnosis of infection after total hip arthroplasty. Methods: This cross-sectional study (Level of Evidence II) was conducted with prospective data on 29 patients submitted to PJA with PTPB at the National Institute of Orthopedics and Traumatology from September 2015 to January 2016. Specimens obtained during the procedures underwent microbiological analyses, and the results were compared with those obtained in subsequent revision arthroplasty surgeries. Results: PJA, PTPB, and their combination reached values of 78%, 73%, 89% for sensitivity, respectively; 72%, 90%, 94% for specificity; and 76%, 80%, 90% for accuracy. Conclusions: PJA combined with PTPB was sensitive, specific, and effective in diagnosing periprosthetic hip infection. Level of Evidence II, Prospective Cross-Sectional Study

Management in patient with rheumatoid arthritis and tuberculous arthritis: a case report

Rheumatoid arthritis (RA) is mainly treated with immunosuppressive drugs, which affects the immunological system. Therefore, the risk of tuberculosis was increased two to ten times in RA patients. Moreover, immunosuppressant is contraindicated in patients with tuberculosis arthritis. A 51-year-old male was presented with pain in his left elbow after he slipped on the floor. He was diagnosed with RA for 16 years and only took prednisone for six years. Six months before, he came to a rheumatologist and was given corticosteroid for six months for RA. The left elbow radiograph and joint aspiration revealed a tuberculosis infection. The patient treated with chloroquine and oral antituberculosis for one year and showed good clinical outcomes. Other diseases should be suspected in RA with uncommon symptoms. Chloroquine is the drug of choice in RA patients with tuberculosis who are contraindicated in immunosuppressant therapy because chloroquine has no immunosuppressant effect.

The Role of Synovial Fluid Aspiration in Shoulder Joint Infections

Background: Joint aspiration with analysis of synovial fluid white blood cell count (WBC) and microbiological culture is a widely established aspect in the diagnosis of shoulder joint infections (SJI). In case of a two stage revision for SJI, joint aspiration before re-/implantation of an total shoulder arthroplasty (TSA) was used to rule out persistent infection for years but its value is under debate. Shoulder specific data on all aspects is rare. The current study aims to answer the following research questions: Joint aspiration has an insufficient predictive value in the diagnosis of SJI in (1) initial workup and (2) before definite arthroplasty with polymethylmethacrylate (PMMA)-Spacer in place. Methods: This retrospective evaluation investigates 35 patients that were treated for SJI with a two staged implantation of a TSA after debridement and implantation of an PMMA-Spacer. Joint aspirations were performed preoperatively (PA) and before re‑/implantation of the prosthesis while spacer was in place (interstage aspiration, IA). Samples were taken for microbiological culture and analysis of WBC. Sensitivity and specificity were calculated with reference to intraoperative microbiological samples. Receiver Operating Characteristic (ROC), Area-Under-Curve analysis (AUC) and calculation of the Youden index were performed to find optimum cut-off for WBC. Results: The sensitivity of microbiological cultures from PA was 58.3% and the specificity was 88.9%. The mean WBC was 27 800 leucocytes/mm3 (range 400-96 300). The maximum Youden index (0.857) was a cut-off of 2600 leucocytes/mm³ with a sensitivity of 85.7% and a specificity of 100.0%. The sensitivity and specificity of IA were 0.0% and 88.5%, respectively. Conclusions: PA is likely to miss Cutibacteria spp. Cuand CoNS and cannot rule out infection for sure. However, we recommend PA for its advantages of targeted antibiotic therapy in case of germ identification. Empiric antibiotic therapy should therefore cover these bacteria even if aspiration showed negative microbiological cultures. In contrast, diagnostic value of IA does not qualify for routine use. Trial registration: The study was approved by the ethic committee of the author`s institution (registration number 235/16-mk). The patients gave written informed consent to their inclusion in the study.

Adherence to a reliable PJI diagnostic protocol minimizes unsuspected positive cultures rate

Background The aim of the present study was to evaluate the incidence of unsuspected PJI when prosthetic revisions are thoroughly evaluated by PJI dedicated orthopedic surgeon before surgery. The hypothesis is that the incidence of unsuspected PJI is reduced by applying this protocol. Methods This is a historical cohort study carried out in one university hospital. The prosthetic revision assessment was carried out in January 2019. From that date on, all patients that were programmed for hip or knee revision (either by an orthopedic surgeon specialized or not in septic revisions) were scheduled for a preoperative visit with the same orthopedic surgeon specialized in septic revisions. The diagnostic algorithm applied was based on the Pro-Implant Foundation diagnostic criteria. Prior to the revision assessment, the indication for joint aspiration was done at the surgeons’ discretion (non-specialized in septic revisions) and the preoperative identification of PJI was also done by a hip or knee surgeon (not specialized in septic surgery). Results Based on the PIF criteria, there were 15 infections among the revisions in group 1 and 18 PJI in group 2 (p > 0.05). The most interesting finding was that there were 7 patients with unsuspected positive cultures in group 1. That represents 11% of all revisions. No patient in group 2 was found with unsuspected positive cultures (p < 0.001). Conclusion A thorough PJI diagnostic algorithm should be implemented before prosthetic revision to avoid unsuspected positive cultures.

Diagnostic value of routine pre-operative investigations used in combination in the diagnosis of periprosthetic joint infection

The primary aim of this study was to assess the diagnostic accuracy of joint aspiration culture, serum C-reactive protein (CRP) and serum erythrocyte sedimentation rate (ESR), individually, and in combination for the diagnosis of periprosthetic joint infection (PJI). A consecutive patient series with pre-operative inflammatory marker levels, an aspiration culture of either hip or knee arthroplasty and intra-operative culture samples from subsequent revision surgery was compiled. This retrospective patient cohort analysis included 128 aspiration. The data were analysed to compare pre-operative aspiration cultures, serum ESR and CRP levels to the chosen gold standard for PJI diagnosis of intra-operative culture samples. A diagnostic algorithm was created using the above tests combined with clinical suspicion index. The values that had the highest sensitivity and specificity of predicting PJI were >5 for CRP and >16 for ESR. CRP used individually had the highest sensitivity and negative predictive value (NPV) of any test (75.0% and 75.9%, respectively). ESR + aspirate had the highest specificity and positive predictive value (PPV), of 100% for both. Using all three tests together the specificity and PPV were higher than the test individual values (95.3% and 85.0% respectively). Based on subgroup analyses the combination of ESR or CRP plus joint aspiration has superior PPV compared to individual tests. ESR and CRP had the highest NPV when used in isolation. An algorithm has been developed to guide clinical diagnosis.

Acute calcific periarthritis secondary to calcium hydroxyapatite crystal deposition in the wrist: a case report

ABSTRACT Acute calcific periarthritis (ACP) is an unusual cause of monoarticular pain characterised by the deposition of calcium hydroxyapatite in the peri-articular and intra-articular tissues. Although the most commonly affected joint is the shoulder, other joints may be involved, including the wrist. This case report describes a 57-year-old female presenting with wrist pain and swelling associated with amorphous calcification overlying the lunate. The patient improved with the use of non-steroidal anti-inflammatory drugs and splinting. Clinician awareness of the clinical presentation and radiographic features of ACP is important to reduce unnecessary invasive diagnostic procedures such as joint aspiration.