Dr Claire Diver

PhD PGCertRes MCSP FSOM

}  Answer following questions: ◦  Why aspirate? ◦  What is the clinical significance of aspirate? ◦  What is the most accurate approach for needle

placement in the knee joint? ◦  Are there prognostic indicators of outcome in OA

knee management with corticosteroid injection?

Diagnosis 1.  Acute synovitis ◦  Sepsis ◦  Crystals

�  Common: monosodium urate (MSU); calcium pyrophosphate (CPPD)

�  Rare: oxalate; cholesterol 2.  Chronic arthropathy ◦  Crystals (MSU; CPPD) Courtney and Doherty, 2005 Courtney and Doherty, 2009

Treatment 1.  Common ◦  To decrease intra-articular pressure ◦  Injection of steroid

2.  Less common ◦  Recurrent aspiration for sepsis ◦  Saline lavage for resistant arthropathy

Courtney and Doherty, 2005 Courtney and Doherty, 2009

}  Research ◦  Measuring biomarkers of joint disease especially OA ◦  Need to compare SF from normal joints with

diseased joints

Pascual and Doherty, 2009

}  Aseptic no-touch technique }  Gloves- to protect operator }  Position patient with joint relaxed }  Avoid blood vessels or cellulitis at the point of

entry }  21g or larger needle for knee }  20ml syringe }  Synovial fluid collection bottles: ? Glass phial/

tube to view fluid }  If using CSI then do not aspirate to dryness

Courtney and Doherty, 2005 Courtney and Doherty, 2009

}  Incorrect needle placement }  If flow of aspiration ceases: ◦  Obstruction by synovial fronds ◦  Obstruction by fibrin and debris ◦  Loculation of synovial fluid ◦  Needle displacement during technique

Courtney and Doherty, 2005

Courtney and Doherty, 2009

Courtney and Doherty, 2009

Courtney and Doherty, 2009

Courtney and Doherty, 2009

Courtney and Doherty, 2009

Supero-lateral Supero-medial

Hermans, J., et al 2011

Medial mid-patellar Lateral mid-patellar

Hermans, J., et al 2011

Antero-medial Antero-lateral

Hermans, J., et al 2011

}  Systematic review: Hermans, J., et al 2011. }  9 articles: reviewed using QUADAS risk of bias

tool }  Superolateral approach studied most (n=6)

Where effusion or synovitis present (2 studies) pooled accuracy was 98% (95%CI 95-100%)

}  Length of needle 1.5-2” increased accuracy }  1 study identified addition of traction in patients

with K&L OA Grade IV increased accuracy in antero-medial and antero-lateral approaches

}  N=1 adverse event

}  Systematic review: Maricar et al, 2013 }  11 studies: meta-analysis not possible given

large degree of heterogeniity }  Possible predictors include: ◦  Effusion ◦  Aspiration ◦  Disease severity ◦  US guided injections