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Hyaluronan (HA)-binding protein involved in HA depolymerization (HYBID) is involved in cartilage destruction via HA depolymerization in human knee osteoarthritis. However, roles of HYBID in the progression of osteoarthritis remain elusive. This study sought to examine whether genetic depletion of Hybid could suppress surgically induced osteoarthritis of mouse knee joints. In osteoarthritis induced by medial collateral ligament transection with meniscus removal, articular cartilage destruction and osteophyte formation at the medial femoral-tibial joint were significantly inhibited in Hybid-deficient (Hybid-/-) mouse group compared to wild-type group. Hybid was highly produced by synovial cells and articular chondrocytes in wild-type mouse osteoarthritis joint. Interleukin-1β, interleukin-6 and tumor necrosis factor-α were up-regulated in the osteoarthritis joint tissues of both wild-type and Hybid-/- mice. Vascular density at the synovial and periosteal junction was significantly reduced in Hybid-/- mice compared to wild-type mice. High-molecular-weight HA was accumulated in osteoarthritis joint tissues of Hybid-/- mice. Injections of high-molecular-weight HA to knee joints attenuated the cartilage destruction and osteophyte formation in wild-type mouse osteoarthritis group. Inhibition of cartilage destruction and osteophyte formation in Hybid-/- mice was also observed in destabilization of the medial meniscus model. These data are the first to demonstrate that cartilage destruction and osteophyte formation are suppressed in Hybid-/- mice and suggest that Hybid-mediated HA depolymerization is implicated for the progression of mechanically induced knee osteoarthritis.

We investigate how meniscus shaping the top surface of liquid samples tested in a semi-open cell impacts results of broadband permittivity measurement. To this end, we utilize the scattering parameters of the samples with flat and distorted surfaces calculated using electromagnetic simulations in the frequency range up to 18 GHz. For determining the permittivity, we process the data using the Nicolson-Ross-Weir (NRW) technique and compare its results with the data obtained with our new meniscus removal method. This comparison clearly shows, particularly at higher microwave frequencies, that the meniscus removal approach brings about smaller errors than the established NRW technique.

The menisci perform crucial tasks for the normal functioning and homeostasis of the knee. Meniscus removal, which is still necessary in many instances, reduces the contact areas and increases the peak stresses in the femorotibial joint which in turn may cause cartilage wear, pain and loss of knee function. The greater the tissue mass excised, the more important the degenerative changes. This process, so-called postmeniscectomy syndrome, is worse in the lateral compartment, due to its particular features. Arthroscopic partial lateral meniscectomies gives excellent short-term outcomes. However, their results deteriorate overtime and are associated with a high incidence of arthritic changes and low functional outcomes. A cautious meniscal removal policy is warranted to avoid these deleterious effects.

Electronic colon cleansing (ECC) aims to remove the contrast agent from the CT abdominal images so that a virtual model of the colon can be constructed. Virtual colonoscopy requires either liquid or solid preparation of the colon before CT imaging. This paper has two parts to address ECC in both preparation methods. In the first part, meniscus removal in the liquid preparation is studied. The meniscus is the curve seen at the top of a liquid in response to its container. Left on the colon wall, the meniscus can decrease the sensitivity and specificity of virtual colonoscopy. We state the differential equation that governs the profile of the meniscus and propose an algorithm for calculating the boundary of the contrast agent. We compute the surface tension of the liquid-colon wall contact using in-vivo CT data. Our results show that the surface tension can be estimated with an acceptable degree of uncertainty. Such an estimate, along with the meniscus profile differential equation will be used as an a priori knowledge to aid meniscus segmentation. In the second part, we study ECC in solid preparation of colon. Since the colon is pressurized with air before acquisition of the CT images, a prior on the shape of the colon wall can be obtained. We present such prior and investigate it using patient data. We show the shape prior is held in certain parts of the colon and propose a method that uses this prior to ease pseudoenhancement correction.

Among 1060 histologically examined meniscus cartilages from patients aged 11--74 years 20 (2%) had chondrocalcinosis. Age at onset of symptoms was 28--67 years, duration of symptoms until surgical removal of the meniscus six weeks to 20 years. All patients had pain, 12 had pain-independent limitations of knee movement. Effusions of the knee were present in ten. Independent of the radiological findings, in the majority of patients the symptoms were markedly improved or completely absent one-two years after meniscus removal. All meniscus specimens revealed severe changes both macroscopically and histologically. The clinical diagnosis confirmed by demonstrating calcium pyrophosphate crystals in haemalauneosin stained sections, examined by polarisation microscopy. The X-ray films demonstrated arthrosis in at least 50% of cases. There appeared to be a close mutual relationship between chondrocalcinosis and arthrosis of the knee-joint.