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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.

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.

Le meniscectomie parziali artroscopiche hanno mostrato migliori risultati clinici rispetto alla rimozione completa del menisco, ma a lungo termine un numero consistente di questi pazienti subiscono l'effetto degenerativo della perdita della cartilagine meniscale. Infatti è estremamente importante preservare il menisco per quanto possibile, al fine di evitare la progressiva degenerazione del ginocchio. Durante gli anni ’80 Stone, Steadman e Rodkey hanno sviluppato un nuovo scaffold in collagene per sostituire il menisco in caso di rotture parziali/subtotali irreparabili: il CMI (Collagen Meniscus Implant). Dopo 13 anni di buoni risultati nell’impianto del CMI mediale, nel 2006 abbiamo iniziato uno studio postmarketing per valutare l'efficacia e la sicurezza di uno scaffold meniscale equivalente appositamente costruito per riparare il menisco laterale (CMI laterale). In questo articolo descriviamo le indicazioni per l'impianto di un dispositivo CMI, l'evoluzione della tecnica chirurgica (da una tecnica di sutura artroscopia “in-out” ad una “all-inside”) in questi 13 anni di esperienza insieme ad una breve relazione sui nostri risultati clinici.

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.