Arthramid Vet White Paper

Understanding the complexity of disease processes associated with joint pain remains a constant dilemma in clinical practice and as with any disease process, an accurate diagnosis is essential.

Arthritis describes inflammation of a joint and can occur after single or repetitive episodes of trauma. The term incorporates synovitis, capsulitis, sprain, intra-articular fractures, meniscal tears, and osteoarthritis(OA). Sub-chondral bone injury also plays a role.

These pathological conditions are ‘a group of overlapping distinct diseases which may have different aetiologies, but with similar biologic, morphologic, and clinical outcomes.

Although conventional concepts of OA emphasise the direct and predominant involvement of cartilage and bone in OA development, it is increasingly recognised that the synovium also contributes to the central pathophysiological event of cartilage matrix depletion.

Cases suitable for treatment with Arthramid®Vet are those in which lameness is localised to the joint by clinical examination, intra-articular analgesia, radiography, ultrasound, MRI, CT and/or Scintigraphy. Conditions that respond to treatment with Arthramid®Vet include acute and chronic synovitis, capsulitis, meniscal tears, OA, and subchondral bone cysts. It is essential that anamnesis of data of ongoing infection, concomitant medication, surgery or potential fracture is reviewed prior to injection to prevent possible infections or use of the product for conditions other than for which it is indicated.

Animals should be rested for 48 hours immediately after treatment. After this time the animal can return to exercise compared to its level of comfort.

Clinical studies show that tissue integration and subsequent augmentation of the joint capsule takes between 2 and 4 weeks to occur, although a response to treatment can be seen earlier than that in some cases.

Animals typically show a gradual reduction in lameness during the first week after treatment and a concurrent reduction in reaction to passive flexion. This continues to improve over the ensuing 2 to 3 weeks. By 4 weeks no further improvement is expected. Re-examination at 4 weeks is therefore indicated to either administer a second dose – in those that have only partially responded- or to reassess accuracy of the diagnosis.

It is important for owners to understand the time lag for a treatment effect to be seen as this contrasts with conventional therapies. In this respect and due to its long lasting effect it may also be prudent to consider treating the animal during periods of reduced exercise demands or early on in the animals training programme.

PAAG products, although often considered equal, have clear differences in composition, manufacturing and injection techniques as well as their ability to interact with surrounding tissues. Characteristics that determine the safety and effectiveness of each hydrogel.

Upon injection into joints, the Arthramid® Vet, a uniquely cross-linked 2.5% polyacrylamide hydrogel, adheres to the synovial lining through its ability to exchange water molecules. The ensuing influx of mononuclear cells reduces exposure of synoviocytes to pro-inflammatory cytokines in the inflamed or diseased joint. The gel becomes progressively integrated into the synovial lining and its immediate surrounding tissue of the inner joint capsule by a combination of cell migration and vessel ingrowth forming a thick, cushion-like membrane, over 14 to 28 days, consisting of vessel integrated gel covered by a new and hypercellular synovial cell lining.

Arthramid®Vet, therefore, has an augmentation effect on the joint capsule and synovium, increasing elasticity and tensile strength and improving its capacity to transfer load. This augmentation and cushioning causes a subsequent reduction in mechanoreceptor and nociceptor activation in the capsule itself. In turn, this further reduces synovitis and its successively deleterious effects as a result.

Unlike other hydrogels, Arthramid®Vet becomes fully integrated into the surrounding tissue (rather than encapsulated) and is therefore long-lasting. Arthramid®Vet does not elicit a foreign body reaction or harbour infection.