Compression-Assisted Arthrocentesis of the Knee as a Quality Improvement Intervention

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 (1 mg/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 u003c3.7u003c 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 (pu003c0.00001, 95% CI of difference 1.2 u003c1.8u003c 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 (pu003c0.00001, 95% CI of difference -0.83 u003c-0.70u003c -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) (pu003c0.0001, 95% CI of difference 47 u003c80u003c 112). Conclusions: Routine mechanical compression of the knee for arthrocentesis and injection is an effective bioengineering quality improvement intervention in a procedure clinic.