Capsular visualization in lipohemarthrosis of the knee

Icariin protects cerebral neural cells from ischemia‑reperfusion injury in an in vitro model by lowering ROS production and intracellular calcium concentration

Ischemia is one of the major causes of stroke. The present study investigated the protection of cultured neural cells by icariin (ICA) against ischemia-reperfusion (I/R) injury and possible mechanisms underlying the protection. Neural cells were isolated from neonatal rats and cultured in vitro. The cells were subjected to oxygen-glucose deprivation and reoxygenation (OGD-R) as an I/R mimic to generate I/R injury, and were post-OGD-R treated with ICA. Following the treatments, cell viability, apoptosis, reactive oxygen species (ROS), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and Ca²⁺ concentration were assessed using Cell Counting Kit-8 assay, flow cytometry, CyQUANT™ LDH Cytotoxicity Assay, H₂DCFDA and SOD colorimetric activity kit. After OGD-R, considerable I/R injury was observed in the neural cells, as indicated by reduced cell viability, increased apoptosis and increased production of ROS and LDH (P<0.05). Cellular Ca²⁺ concentration was also increased, while SOD activity remained unchanged. Post-OGD-R ICA treatments increased cell viability up to 87.1% (P<0.05) and reduced apoptosis as low as 6.6% (P<0.05) in a concentration-dependent manner. The treatments also resulted in fewer ROS (P<0.05), lower extracellular LDH content (440.5 vs. 230.3 U/l; P<0.05) and reduced Ca²⁺ increase (P<0.05). These data suggest that ICA protects the neural cells from I/R injury in an in vitro model through antioxidation activity and maintaining cellular Ca²⁺ homeostasis. This function may be explored as a potential therapeutic strategy for ischemia-related diseases after further in vivo studies.

Traumatic lipohemobursa of the infrapatellar bursa

Displaced fractures allow spillage of bone marrow and blood into the surrounding soft tissues. When the fracture is intra-articular, the spilled marrow contents may be contained by the associated joint capsule, resulting in a lipohemarthrosis. This is sometimes visible as a fat-fluid level on imaging. At the knee, the characteristic appearance of lipohemarthrosis within the suprapatellar recess signifies the presence of an intra-articular fracture that may otherwise not be radiographically apparent. We present a case in which an extra-articular proximal tibia fracture allowed spillage of marrow contents into the deep infrapatellar bursa, resulting in a lipohemobursa. The radiologic appearance mirrors the classic appearance of lipohemarthrosis with a fat-fluid level.

Evolving stages of lipohemarthrosis of the knee. Sequential magnetic resonance imaging findings in cadavers with clinical correlation

RATIONALE AND OBJECTIVES

Lipohemarthrosis, the presence of fat and blood in a joint cavity, exhibits several complex layers related to differences in specific component relaxation on magnetic resonance (MR) images. The authors investigated sequential changes in the appearance of lipohemarthrosis of the knee as demonstrated by MR imaging.

METHODS

Sequential MR imaging over a 4-day period was performed on two cadaveric knees after intraarticular injection of blood from a volunteer and fat from a cadaveric tibia (50 mL of blood and 25 mL of fat in one knee and 15 mL of blood and 5 mL of fat in the other knee). The authors determined components in the joint based on MR signal behavior. Magnetic resonance imaging examinations of four patients with intracapsular fractures and lipohemarthroses of the knee were reviewed retrospectively.

RESULTS

Sequential MR images of cadaveric knees showed serial changes representing progressive formation and lysis of blood clot. Several fluid-fluid levels (globules of fat at the interface between fat and blood) and entrapment of fat were early findings of lipohemarthrosis. Three different fluid levels appeared approximately 3 hours after injection of fresh blood and marrow fat. The 96-hour study demonstrated three distinct levels.

CONCLUSIONS

Lipohemarthrosis demonstrates temporal changes on MR imaging related to stages of formation and lysis of blood clot.

Radiology of the suprapatellar region

The gross and radiological anatomy of the suprapatellar region has been reviewed and its clinical application outlined. In most patients an accurate assessment of the presence of effusion and lipohaemarthrosis of the knee joint can be made and the possibility of excluding joint disease is discussed. In the individual patient the careful application of the radiological anatomy of this region may prevent mistakes in the localisation of various pathological processes.

The double fat fluid level: lipohemarthrosis of the knee associated with suprapatellar plica synovialis

Lipohemarthrosis is a frequent occurrence following intrarticular fracture. The contour of the fat and blood interface in the knee joint is dependent upon suprapatellar anatomy. Anatomic variations of the suprapatellar joint space can significantly alter the radiographic appearance of lipohemarthrosis. Three cases are presented in which a double fat-fluid level was identified, due to presence of a well developed suprapatellar plica synovialis. Recognition of the variable appearance of lipohemarthrosis of the knee is important to avoid overlooking this finding in the traumatized patient.

Lipohemarthrosis: its occurrence with occult cortical fracture of the knee

Three patients with fat fluid levels in the knee following trauma were shown to have small cortical fractures. None of the fractures was visible in routine roentgenograms. Because of the finding of the lipohemoarthrosis in each case, additional roentgenograms were taken until small cortical fractures could be visualized.