Ultrasound Image of Non-Effusive Knee with and without Pneumatic Compression (medial knee). The figure on the left is the flexed non-effusive knee, where the needle (Needle) cannot access the synovial fluid because the fat pad (Fat Pad) forces fluid from the surface of cartilage to the superior knee (Cartilage). The figure on the right is non-effusive knee with the pneumatic compression that compresses the suprapatellar bursa and inducing collapse driving the occult synovial fluid (Occult Extractable Fluid) inferiorly where the fluid collects over the cartilage surfaces (Cartilage) of the medial femoral condyle (Medial Femoral Condyle) displacing the fat pad (Fat Pad). The synovial fluid (Occult Extractable Fluid) can then be accessed by the needle (Needle).

Contexts in source publication

Context 1

... this way, without the use of human hands susceptible to needle stick, the thigh cuff 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 ( Figures 2 and 3). After the pneumatic cuff was inflated to 100 mm Hg on the superior knee, 1-3 minutes were permitted to allow occult fluid to move from the superior knee to the inferior knee where it could be accessed ( Figure 3). Arthrocentesis success, and fluid yield again were recorded. ...

Context 2

... inability to fully extract synovial fluid from the non-effusive knee is due to minimal resident synovial fluid, the thin synovial fluid layer over the cartilage surfaces, mistargeting by the needle, and the complex foldings of the villi and discrete intraarticular synovial compartments that retain viscous occult synovial fluid [9,10,[21][22][23][24][25][26][27][28][29]36,37]. The present study demonstrates that external pneumatic compression of the noneffusive knee (Figure 1) mobilizes occult synovial fluid, dilates the joint space target with displaced occult fluid ( Figure 2) and permits fluid flow to the femoral condyles where the synovial fluid can be accessed using the anterolateral portal (Figure 3) [19,[37][38][39][40][41][42]. ...

Context 3

... despite pneumatic compression forcing synovial fluid from the suprapatellar bursa and superior knee to the femoral condyles where the fluid could be accessed, the fluid over the femoral condyle was layered quite thin dimensionally due to the restricted compressibility of adjacent fat pad (Figures 2 and 3). Thus, the needle often had to be rotated in the long axis so that the needle bevel was properly positioned in the fluid layer ( Figure 3). ...

Context 4

... this way, without the use of human hands susceptible to needle stick, the thigh cuff 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 ( Figures 2 and 3). After the pneumatic cuff was inflated to 100 mm Hg on the superior knee, 1-3 minutes were permitted to allow occult fluid to move from the superior knee to the inferior knee where it could be accessed ( Figure 3). Arthrocentesis success, and fluid yield again were recorded. ...

Context 5

... inability to fully extract synovial fluid from the non-effusive knee is due to minimal resident synovial fluid, the thin synovial fluid layer over the cartilage surfaces, mistargeting by the needle, and the complex foldings of the villi and discrete intraarticular synovial compartments that retain viscous occult synovial fluid [9,10,[21][22][23][24][25][26][27][28][29]36,37]. The present study demonstrates that external pneumatic compression of the noneffusive knee (Figure 1) mobilizes occult synovial fluid, dilates the joint space target with displaced occult fluid ( Figure 2) and permits fluid flow to the femoral condyles where the synovial fluid can be accessed using the anterolateral portal (Figure 3) [19,[37][38][39][40][41][42]. ...

Context 6

... despite pneumatic compression forcing synovial fluid from the suprapatellar bursa and superior knee to the femoral condyles where the fluid could be accessed, the fluid over the femoral condyle was layered quite thin dimensionally due to the restricted compressibility of adjacent fat pad (Figures 2 and 3). Thus, the needle often had to be rotated in the long axis so that the needle bevel was properly positioned in the fluid layer ( Figure 3). ...