Archive for August 28, 2019

Fever and Erythema are Specific Findings in Detecting Infection Following Total Knee Arthroplasty.

J Bone Jt Infect. March 16, 2019 V.4 B.2 P.92-98. doi: 10.7150/jbji.30088. eCollection 2019.

Shohat N1,2, Goswami K1, Tan TL1, Henstenburg B1, Makar G1, Rondon AJ1, Parvizi J1.

1 The Rothman Institute at Thomas Jefferson University, Philadelphia, PA 19107.

2 Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.


Current diagnostic modalities are based almost exclusively on laboratory findings and the role of clinical presentation remains unknown. The purpose of this study was to examine the diagnostic value of clinical presentation in detecting periprosthetic joint infection (PJI). This study evaluated 279 patients undergoing revision surgery for failed total knee arthroplasty (TKA) between 2001-2016. Patients were classified as undergoing septic revisions based on major MSIS criteria. Aseptic revisions were defined as cases of single stage revision that did not have suspected PJI, fulfill MSIS criteria, or subsequently fail within one year of follow-up. Clinical presentation included pain, fever, presence of joint effusion or erythema, and reduced range of motion. Serum and synovial laboratory markers were also evaluated. The diagnostic value of each test was assessed and a Fagan’s nomogram was constructed. A subset of MSIS-negative patients was used to demonstrate the value of various clinical presentations in detecting PJI. Post-test probability for infection was calculated taking into account clinical presentation together with serum and synovial markers. Our results show that fever and erythema are the most important signs for diagnosing PJI with a positive likelihood ratio (LR) of 10.78 and 8.08, respectively. Effusion had a LR of 2.42. Pain and reduced ROM were not as strongly correlated with PJI diagnosis; LR was 1.02 and 1.51. Of the 35 MSIS-negative patients treated for PJI, 33 had a post-test probability of infection greater than 90% when taking clinical presentation into account. Clinical presentation should be used to guide which future diagnostic tests should be ordered and in the interpretation of their results. Our results indicate that pain, fever, presence of joint effusion or erythema, and reduced range of motion should prompt further workup for infection. We propose a nomogram that may be used in interoperating their individual weight together with laboratory findings. Fever and erythema are highly specific findings in patients with PJI and future studies should assess whether they may be added as minor criteria to current definitions for infection.


August 28, 2019 at 3:52 pm

Is Gram staining still useful in prosthetic joint infections?

J Bone Jt Infect. January 29, 2019 V.4 N.2 P.56-59.

doi: 10.7150/jbji.31312. eCollection 2019.

Wouthuyzen-Bakker M1, Shohat N2,3, Sebillotte M4, Arvieux C4,5, Parvizi J2, Soriano A6.

1 Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, the Netherlands.

2 Rothman Institute at Thomas Jefferson University Hospital, Philadelphia, United States.

3 Department of Orthopaedic Surgery, Tel Aviv University, Tel Aviv, Israel.

4 Department of Infectious Diseases and Intensive Care Medicine, Rennes University Hospital, Rennes, France.

5 Great West Reference centers for Complex Bone and Joint Infections (CRIOGO), France.

6 Service of Infectious Diseases, Hospital Clínic, University of Barcelona, Barcelona, Spain.


Introduction: Staphylococcus aureus is an independent risk factor for DAIR failure in patients with a late acute prosthetic joint infection (PJI). Therefore, identifying the causative microorganism in an acute setting may help to decide if revision surgery should be chosen as a first surgical approach in patients with additional risk factors for DAIR failure. The aim of our study was to determine the sensitivity of Gram staining in late acute S. aureus PJI. Material and methods: We retrospectively evaluated all consecutive patients between 2005-2015 who were diagnosed with late acute PJI due to S. aureus. Late acute PJI was defined as the development of acute symptoms and signs of PJI, at least three months after the index surgery. Symptoms existing for more than three weeks were excluded from the analysis. Gram staining was evaluated solely for synovial fluid. Results: A total of 52 cases were included in the analysis. Gram staining was positive with Gram positive cocci in clusters in 31 cases (59.6%). Patients with a C-reactive protein (CRP) > 150 mg/L at clinical presentation had a significantly higher rate of a positive Gram stain (30/39, 77%) compared to patients with a CRP ≤ 150 mg/L (4/10, 40%) (p=0.02). A positive Gram stain was not related to a higher failure rate (60.6% versus 57.9%, p 0.85). Conclusion: Gram staining may be a useful diagnostic tool in late acute PJI to identify S. aureus PJI. Whether a positive Gram stain should lead to revision surgery instead of DAIR should be determined per individual case.


August 28, 2019 at 3:51 pm


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