Diagnosis of Periprosthetic Infection

Abstract

Periprosthetic infections are rare, but there is evidence to suggest that their frequency may be underestimated. No single laboratory test has perfect sensitivity and specificity for diagnosing infection. Most tests have better specificity when they are performed for patients in whom infection is suspected clinically rather than when they are used as screening tests. Screening test results that may suggest the possibility of infection include elevation of the erythrocyte sedimentation rate and/or serum C-reactive protein level more than three months after an arthroplasty. Most serologic tests are difficult to interpret when the patient has an underlying inflammatory arthropathy. Cultures of aspirated joint fluid can be especially helpful for patients who have symptoms suggestive of infection, but their results are best interpreted two weeks after administration of antibiotics has been discontinued. Joint fluid cell counts may also be helpful, but Gram stains of joint fluid have poor sensitivity and specificity. Criteria for diagnosing infection on the basis of frozen sections of implant membranes have not yet been standardized, but in many laboratories more than five neutrophils per high-power field in five or more fields (excluding surface fibrin) has been found to be suggestive of infection. Most polymerase chain reactions that detect the universal 16S rRNA bacterial gene have problems with false-positive results, but combining a universal polymerase chain reaction with subsequent bacterial sequencing can help improve specificity. Polymerase chain reactions can detect necrotic bacteria, so the clinical importance of positive results of this analysis in the absence of other features of infection remains to be determined.

In-Depth Oral Presentations and Oral Communications

“…MPFL was anisometric, the insertion points of the inferior bundles coming closer in flexion. Discussion Reported results are comparable to thosre published by Baldwin et al [1] concerning the patella lateral shift in MPFL-deficient state, but they are different from what reported by Sandmeier et al [2] in different experimental conditions. Conclusions While, MPFL may guide the patella shift and tilt during knee motion, in normal knee trochlear morphology does not influence kinematics.…”

“…Glucosamine, chondroitin sulphate and collagen type II (SYSADOA) in oral administration act like chondroprotective factors. The intake (above 90 days) in combination of these substances is advantageous in osteoarthrosis of the hip (group I-II of the K-L's scale) [1]. Our study has the aim to demonstrate the effectiveness of eco-guided infiltrations with high molecular weight associated with administration of oral chondroprotective supplements (glucosamine solfate, chondroitin sulphate, hydrolyzed collagen type II, hyaluronic acid and L carnitine fumarate) in comparison with the only treatment with ecoguided infiltrations with hyaluronic acid in patients suffering from primary osteoarthritis of the hip.…”

Toll-Like Receptor 2 in Serum: a Potential Diagnostic Marker of Prosthetic Joint Infection?

“…Currently, a large number of tests are available for PJI diagnosis, ranging from hematological markers of infection and inflammation to intraoperative culture and histology analysis. Nevertheless, there is still a lack of gold standards for the diagnosis of PJI (12,13), because the clinical presentation of PJI is often ambiguous (14), and classical inflammatory markers can be misleading (15)(16)(17). In order to optimize the diagnostic process, infection biomarkers with fast response and high sensitivity and specificity for infection are needed (7).…”

pH‐Dependent Coordination of AgI Ions by Histidine: Experiment, Theory, and a Model for SilE

“…4 ] n (3): Compound 3 crystallizes under similar conditions as compound 2 in the form of colorless needles in the triclinic space group P1 (no. 2, see the Supporting Information, Table S1).…”

“…These implant infections occur frequently, either perioperatively, by bacterial contamination of the surgical site, of which mostly low-virulence organisms, including S. epidermidis, are responsible, or postoperatively, by hematogenous infections. [4] These latter infections are the result of the seeding of the implant site by organisms that are transported there in the bloodstream from another infected region. Bacteria on implants typically proliferate and cluster in multilayers of exopolysaccharides, known as biofilms; this structure allows bacteria to resist antimicrobial agents and immune responses.…”