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Extraction of Synovial Fluid from the Non-Effusive Pathologic Knee with Pneumatic Compression
  • +9
  • Ahsan Iqbal, MD,
  • Sumir Brahmbhatt, MD,
  • Maheswari Muruganandam, MD,
  • Jaren R. Trost, MD,
  • Fatemeh Jafari Farshami, MD,
  • David R. Cisneros, MD,
  • Adnan N. Kiani, MD,
  • Matthew K. McElwee, MD,
  • William A. Hayward, PhD,
  • Luke J. Haseler, PhD,
  • Philip A. Band, PhD,
  • Wilmer L. Sibbitt, Jr., MD
Ahsan Iqbal, MD
Sumir Brahmbhatt, MD
Maheswari Muruganandam, MD
Jaren R. Trost, MD
Fatemeh Jafari Farshami, MD
David R. Cisneros, MD
Adnan N. Kiani, MD
Matthew K. McElwee, MD
William A. Hayward, PhD
Luke J. Haseler, PhD
Philip A. Band, PhD
Wilmer L. Sibbitt, Jr., MD
University of New Mexico

Corresponding Author:[email protected]

Author Profile


Objectives –Aspiration of synovial fluid from non-effusive joints is undertaken for the diagnosis of crystal-associated arthritis, biomarker analysis, and to confirm intraarticular positioning. We hypothesized that pneumatic compression of the non-effusive knee would mobilize occult synovial fluid and improve arthrocentesis success. 
Methods – The absence of a knee effusion was determined by physical examination, imaging, and exclusion of confounding disease.  Conventional arthrocentesis was performed in 111 consecutive non-effusive knees and arthrocentesis volume (milliliters) determined. Pneumatic compression was then applied, and arthrocentesis was resumed. 
Results – Pneumatic compression improved fluid yield: conventional: 0.4±1.0 ml, compression: 1.8±2.5 ml (319% increase, 95% CI  -1.9<-1.4<-0.9; p=0.0001). Pneumatic compression reduced arthrocentesis failure (< 0.1 ml) from 74.8% (83/111) to 41.4% (46/111) (p=0.0001) and improved successful arthrocentesis in terms of adequate synovial fluid yield: 1) ≥ 0.1 ml from 25.2% (28/111) to 58.5% (65/111) (+132%, p=0.0001), 2) ≥ 0.5 ml from 22.5% (25/111) to 57.7% (64/111) (+156%, p =0.0001), 3) ≥ 2.0 ml from 11.7% (13/111) to 47.7% (53/111) (+300%, p =0.0001), and 4) ≥ 3.0 ml from 5.4% (6/111) to 36.0% (40/111) (+319%, p =0.0001). 
Conclusions: Pneumatic compression of the non-effusive knee improves the extraction of synovial fluid of various requisite volumes for conventional and biomarker analysis.