Comparison of Two Different Techniques of Synovial Biopsy and Resistances of Cutaneous Smears in Suspected PPI

Study Overview
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Brief Summary
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The purpose of this study is to determine whether an undirected synovial biopsy technique has the same accuracy in detecting periprosthetic joint infection in the knee as an arthroscopic assisted directed synovial biopsy technique.

Detailed Description
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Successful treatment of an infected joint arthroplasty depends on correctly identifying the responsible pathogens. The value of a preoperative biopsy remains controversial. We compared the sensitivity and specificity of two techniques of synovial biopsy of knee joint arthroplasties suspicious for infection and asked whether the results correlate with intraoperative findings at revision.

Official Title
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Comparison of Directed Versus Undirected Synovial Biopsy in Culture-negative Periprosthetic Joint Infections (With Preoperative Smears From the Skin) of the Knee and Evaluation of Outcome After Revision Joint Arthroplasty

Conditions
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Infection of Total Knee Joint Prosthesis

Intervention / Treatment
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* Procedure: synovial biopsy of total knee arthroplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic painful knee prosthesis planned for synovial biopsy to detect infection Culture-negative joint aspiration Exclusion Criteria: Co-morbidities: Tumour disease, immune suppression

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: undirected and directed biopsy<br>Via an antero-lateral incision of the knee samples are taken without visual control; Afterwards an arthroscope is inserted and samples are taken from 5 defined regions of the knee (suprapatellar pouch, medial and lateral gutter, notch, Hoffa's fat pad) | Procedure: synovial biopsy of total knee arthroplasty<br>* synovial biopsies are taken via two different techniques in the same patient to allow direct comparison of results<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of microbiological and histological results of undirected and directed synovial biopsies | 5 microbiological samples and 1 histological sample are taken form the knee undirected via an antero-lateral approach. Afterwards the same sample numbers are taken under arthroscopic view. Correlation of results between those two methods are investigated. If infection is detected two-stage exchange of prosthesis is performed. At this surgery samples from synovia and the implant-bone interface are again taken and again investigated for correlation. | within the first 14 days after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of microbiological results from synovial biopsy with intraoperative findings at revision |  | within the first 14 days after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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synovial biopsy, knee arthroplasty, infection