ABSTRACT
Objective The present study reports the introduction of mechanical compression of the knee for arthrocentesis as quality improvement intervention in a procedure clinic.
Methods 430 consecutive symptomatic osteoarthritic knees underwent arthrocentesis followed by corticosteroid injection (1mg/kg of triamcinolone acetonide). The first 215 consecutive knees underwent conventional arthrocentesis and injection; the quality intervention of a mechanical compression brace was introduced, and the next 215 consecutive knees underwent mechanical compression-assisted arthrocentesis follow by injection. Pain scores, arthrocentesis success, fluid yield, time-to-next-intervention, injections/year, and medical costs were measured.
Results No serious adverse events occurred in 430 subjects. Diagnostic synovial fluid (≥2 ml) was obtained in 9.3% (20/215) without compression and 40.9% (88/215) with compression (p=0.00001, z for 95% CI= 1.96, Pierson). Mechanical compression was associated with a 231% increase in mean arthrocentesis volume: compression 5.3±11.2 ml, conventional 1.6±6.4 ml (CI of difference 2.0 <3.7< 5.4; p=0.00001). Time-to-next-intervention after compression-assisted arthrocentesis was longer: 6.9±3.5 months compared to conventional: 5.1±2.7 months (p<0.00001, 95% CI of difference 1.2 <1.8< 2.3). Mechanical compression was associated with a reduction in the number of corticosteroid injections administered per year: mechanical compression: 1.7±0.9 injections/year; conventional: 2.4±0.5 injections/year (p<0.00001, 95% CI of difference −0.83 < −0.70< −0.56). Mechanical compression did not increase overall yearly costs associated with management of the symptomatic knee (mechanical compression: $293.30/year/knee, conventional: $373.29/year/knee) (p<0.0001, 95% CI of difference 47 <80< 112).
Conclusions Routine mechanical compression of the knee for arthrocentesis and injection is an effective bioengineering quality improvement intervention in a procedure clinic.
