Can Diagnostic and Therapeutic Arthrocentesis Be Successfully Performed in the Flexed Knee?

Sabeen Yaqub, MD; Wilmer L. Sibbitt, Jr, MD; Philip A. Band, PhD; James F. Bennett, MD; N. Suzanne Emil, MD; Monthida Fangtham, MD; Roderick A. Fields, MD; William A. Hayward, PhD; Scarlett K. Kettwich, MS; Luis P. Roldan, BS; Arthur D. Bankhurst, MD

Disclosures

J Clin Rheumatol. 2018;24(6):295-301. 

In This Article

Methods

This quality improvement program and data analysis, formalized in the Division of Rheumatology, Department of Internal Medicine, University of New Mexico Health Science Center, was approved by the institutional review board and was in compliance with the Helsinki Declaration and subsequent revisions. The study design was that typical of a quality improvement program with (1) measurement of baseline quality factors in consecutive traditionally treated patients, (2) introduction of the quality intervention, and (3) remeasurement of quality factors in consecutive patients after the intervention. This project assessed improvement of knee arthrocentesis and injection outcome before and after introduction of constant compression applied by a mechanical brace intended to remove the operator's hands from the operative field and thus from potential needlestick, yet still provide robust compression of the knee during arthrocentesis and injection procedures. Fifty-five total effusive knees were included in this study. The first 20 consecutive clinically effusive knees underwent conventional arthrocentesis with the knee in the extended position using the superolateral approach, the quality intervention was introduced, and the next 35 consecutive effusive knees underwent constant compression assisted arthrocentesis in the flexed position. The presence of a knee effusive was determined clinically by palpation of suprapatellar bursa distention, ballottement of a floating patella, and fluid shift with asymmetric compression confirmed by physical examination. Inclusion criteria included (1) the presence of a clinically palpable knee effusive, (2) indications for therapeutic-diagnostic arthrocentesis, and (3) formal signed consent of the patient to undergo the procedure.

Arthrocentesis and Joint Injection Technique

In all cases, the skin was first cleaned with chlorhexidine 2% for antisepsis. The superolateral portal was determined by palpation and marked with ink. The 1-needle multiple-syringe technique was used where (1) one needle is used for anesthesia and arthrocentesis and (2) a first syringe or syringes are used to anesthetize the synovial membrane and completely aspirate effusion using syringe exchanges if the effusion was large. A 22-gauge 2-inch needle (4710007050, 22-gauge × 2″ [0.7 × 50 mm], FINE-JECT [Henke Sass Wolf, Tuttlingen, Germany]) was mounted on a 3-mL syringe (3-mL Luer-Lok syringe; BD, Franklin Lakes, NJ [https://www.bd.com]) filled with 3 mL of 1% lidocaine (Xylocaine 1%; AstraZeneca Pharmaceuticals LP, Wilmington, DE). Three milliliters of lidocaine was used to first anesthetize the skin, subcutaneous tissues, and synovial membrane as the 22-gauge needle was introduced through the skin into the lateral parapatellar recess of the suprapatellar bursa, and if there was no synovial fluid return, the needle was directed inferiorly under the patella into the patellofemoral joint toward the intercondylar notch. The knee was then compressed or "milked" by the operator's free hand, and a fully conventional arthrocentesis was performed[3–10] (Figure 1). Arthrocentesis success and fluid yield were recorded. The needle was then extracted, and firm pressure applied to the puncture site.

Figure 1.

Conventional extended knee arthrocentesis. The knee is extended with 0- to 20-degree flexion. The needle is introduced through the superolateral portal into the lateral parapatellar recess of the suprapatellar bursa, and if there is no synovial fluid return, the needle is directed inferiorly under the patella into the patellofemoral joint toward the intercondylar notch. The knee is compressed or "milked" by the operator's free hand. Color online-figure is available at https://www.jclinrheum.com.

In the 35 flexed effusive knees, the patient was kept in the sitting position. The anterolateral portal was defined by the adjoining structures of inferolateral border of the patella, the lateral border of the patellar tendon, and the lateral tibial plateau.[12] The needle was directed from the anterolateral portal under the patella through the anterior fat pad, until the needle tip directly penetrated the synovial membrane and the bevel engaged the synovial spaces around medial femoral condyle and/or the cruciate ligaments.[12] The knee was then manually squeezed and "milked" with the free hand to drive further fluid to the aspiration portal. Arthrocentesis success and fluid yield were recorded. The needle was left intra-articularly, and a compressive knee brace (YooSoo adjustable knee brace [Shenzhen Shi Hai Xun Yun Wei Co., Ltd., Shenzhen, China]) was placed on the flexed knee and modified so that the suprapatellar bursa and patellofemoral joint were compressed, not the inferior knee (Figs. 2–4). The brace was tightened so that the brace did not impede arterial flow in the leg, but the patient felt considerable pressure. Placed this way, without the use of human hands susceptible to needlestick, the brace applies constant compression to the suprapatellar bursa, the synovial compartments of the superior medial and lateral knee, and patellofemoral joint, thus collapsing these synovial compartments and forcing fluid inferiorly to the synovial reflections of the femoral condyles and cruciate ligaments where the fluid could be accessed (Figs. 3–6). After the brace was placed on the superior knee, 1 to 3 minutes was permitted to allow fluid to move from the superior knee to the inferior knee where it could be accessed (Figs. 2–4). Arthrocentesis success and fluid yield again were recorded. The needle was then extracted, and firm pressure applied to the puncture site.

Figure 2.

Flexed knee with constant mechanical compression (front view). The constant compression brace is placed over the superior knee, and the brace is tightened so that the brace does not impede arterial flow in the leg, but the patient experiences considerable pressure. Color online-figure is available at https://www.jclinrheum.com.

Figure 3.

Flexed knee with and without constant mechanical compression (front view). The figure on the left represents the flexed effusive knee with synovial fluid pooling in a large effusion in the lateral suprapatellar bursa (SPB Synovial effusion) (diagonal hatch). The figure on the right represents the flexed effusive knee with the constant compression brace (Brace) (broken line) that compresses and collapses the suprapatellar bursa (SPB Collapse) driving the synovial fluid inferiorly into a inferior synovial effusion (INF Synovial effusion) (diagonal hatch) layered over the synovial surfaces of the inferior femoral condyles where the fluid can be aspirated.

Figure 4.

Flexed knee with and without constant mechanical compression (side view). The figure on the left represents the flexed effusive knee with synovial fluid pooling in a large effusion in the lateral suprapatellar bursa (SPB Synovial Effusion) (diagonal hatch). The needle (Needle) cannot access the synovial fluid because the fat pad (Fat Pad) (speckled area) exerts pressure on the inferior knee and forces fluid to the suprapatellar bursa where it pools (SPB Synovial Effusion) (diagonal hatch). The figure on the right represents the flexed effusive knee with the constant compression brace (Brace) (broken line) that compresses and collapses the suprapatellar bursa (SBP Collapse) driving the synovial fluid inferiorly (INF Synovial Effusion) (diagonal hatch) layered over the synovial surfaces of the inferior femoral condyles and compressing the fat pad (speckled area). The inferior synovial effusion (IFN Synovial Effusion) can then be sampled by the needle (Needle).

Figure 5.

Ultrasound image of flexed knee with and without constant mechanical compression (medial knee). The figure on the left represents the flexed effusive knee, but the needle (Needle) cannot access the synovial fluid because the fat pad (Fat Pad) exerts pressure on the inferior knee and forces fluid from the surface of cartilage (Cartilage). The figure on the right represents the flexed effusive knee with the constant compression brace that compresses the suprapatellar bursa and forces the suprapatellar bursa (not seen in this image) to collapse driving the synovial fluid inferiorly where the fluid forms an effusion (Effusion) layered over the cartilage surface (Cartilage) of the medial femoral condyle (Medial Femoral Condyle) and compressing the fat pad (Fat Pad). The inferior synovial effusion (Effusion) can then be sampled by the needle (Needle).

Figure 6.

Arthrocentesis in the flexed knee with constant mechanical compression. After constant compression is applied to the suprapatellar bursa and patellofemoral joint with the constant compression brace, fluid is forced down into the inferior knee where it can be accessed by the anterolateral portal. Color online-figure is available at https://www.jclinrheum.com.

Outcome Measures

Patient pain was measured with the standardized and validated 0- to 10-cm visual analog pain scale (VAS pain scale), where 0 cm = no pain and 10 cm = unbearable pain.[28,29] Pain by VAS was determined (1) prior to the procedure (baseline pain), (2) during arthrocentesis (procedural pain), and (3) immediately postprocedure (postprocedural pain). Aspirated fluid volume was quantified in milliliters. Diagnostic fluid was defined as greater than or equal to 2.0 mL (1 mL for culture and 1 mL for cell counts and crystal examination). Fluid was evaluated for cell counts, crystals, and Gram stain and sent for culture and sensitivity as appropriate. Patients were also observed for serious adverse events.

Statistical Analysis

Data were entered into Excel (version 5; Microsoft, Seattle, WA) and analyzed in SAS (SAS/STAT Software, Release 6.11; SAS Institute Inc., Cary, NC). A power calculation was made using preliminary data at this level where α = 0.0001, power = 0.9, and allocation ratio = 1.0 indicated that n = 20 in each group would provide statistical power at the P < 0.05 level and n = 30 in each group at the P < 0.02 level. Pearson χ 2 2 × 2 table analysis was performed on categorical data calculating both P values and confidence intervals (CIs) with significance reported at the P < 0.05 level. Measurement data were analyzed using the Student t test calculating both P values and CIs.

processing....