Improvement in diagnostic and therapeutic arthrocentesis via constant compression

Abstract

We hypothesized that constant compression of the knee would mobilize residual synovial fluid and promote successful arthrocentesis. Two hundred and ten knees with grade II-III osteoarthritis were included in this paired design study: (1) conventional arthrocentesis was performed with manual compression and success and volume (milliliters) determined; and (2) the intra-articular needle was left in place, and a circumferential elastomeric brace was tightened on the knee to provide constant compression. Arthrocentesis was attempted again and additional fluid volume was determined. Diagnostic procedural cost-effectiveness was determined using 2017 US Medicare costs. No serious adverse events were noted in 210 subjects. In the 158 noneffusive (dry) knees, sufficient synovial fluid for diagnostic purposes (≥ 2 ml) was obtained in 5.0% (8/158) without compression and 22.8% (36/158) with compression (p = 0.0001, z for 95% CI = 1.96), and the absolute volume of arthrocentesis fluid obtained without compression was 0.28 ± 0.79 versus 1.10 ± 1.81 ml with compression (293% increase, p = 0.0001). In the 52 effusive knees, diagnostic synovial fluid (≥ 2 ml) was obtained in 75% (39/52) without compression and 100% (52/52) with compression (p = 0.0001, z for 95% CI = 1.96), and the absolute volume of arthrocentesis without compression was 14.7 ± 13.8 versus 25.3 ± 15.5 ml with compression (72.1% increase, p = 0.0002). Diagnostic procedural cost-effectiveness was $655/sample without compression and $387/sample with compression. The new technique of constant compression via circumferential mechanical compression mobilizes residual synovial fluid beyond manual compression improving the success, cost-effectiveness, and yield of diagnostic and therapeutic arthrocentesis in both the effusive and noneffusive knee.

Ultrasound measurement of knee synovial fluid during external pneumatic compression

“…In a recent study using non-pneumatic compression in OA patients undergoing aspirations, the authors reported an increase in synovial fluid was obtained after constant external compression of the knee was applied during arthrocentesis. 23 Our findings support and extend these earlier results. Patient discomfort may also be reduced if the provider has a larger target area available for aspiration or injection and is, therefore, less likely to have the needle inadvertently strike pain-sensitive structures such as the periosteum, joint capsule, fascia, or muscle if initial non-image guided needle insertion is unsuccessful during attempted aspiration.…”

“…Some of our morbidly obese patients required a larger modified compression device for successful aspirations or injections. In a recent study using non‐pneumatic compression in OA patients undergoing aspirations, the authors reported an increase in synovial fluid was obtained after constant external compression of the knee was applied during arthrocentesis . Our findings support and extend these earlier results.…”

“…Patient discomfort may also be reduced if the provider has a larger target area available for aspiration or injection and is, therefore, less likely to have the needle inadvertently strike pain‐sensitive structures such as the periosteum, joint capsule, fascia, or muscle if initial non‐image guided needle insertion is unsuccessful during attempted aspiration. It has also previously been reported that patients experienced a 43% reduction in procedural pain when US guided needle placement was utilized rather than landmark techniques …”

“…There may also be greater detail observed on US images from RA patients since a larger area frequently identifies enhanced detail on the size of the synovial pannus and provides a larger area available for inspection and possibly to address adequacy of therapy following biologic therapy as reviewed by Vlad et al We did not perform power Doppler examination on the knees in this study so we cannot address if inflation to 100 mmHg might influence blood flow as assessed by power doppler signal generation. Multiple studies have confirmed that accuracy and therapeutic benefit is enhanced using US‐guided knee injections over landmark‐based techniques . However, due to the high cost of most US units, falling reimbursement, and the additional time needed to gain proficiency in musculoskeletal US, there is a need for lower cost alternatives which enhance the accuracy of therapeutic knee injections.…”

“…Multiple studies have confirmed that accuracy and therapeutic benefit is enhanced using US-guided knee injections over landmark-based techniques. [21][22][23] However, due to the high cost of most US units, falling reimbursement, and the additional time needed to gain proficiency in musculoskeletal US, there is a need for lower cost alternatives which enhance the accuracy of therapeutic knee injections. Sibbitt et al have reviewed multiple studies which confirm improved accuracy of intraarticular needle placement using sonographic guidance compared to non-image-guided techniques and they also demonstrated improved efficacy of glucocorticoid administration.…”