Osteoarthritis (OA) is a progressive disease of the joints that is extremely common. Due to its degenerative nature, it more frequently affects older animals, although animals of any age can be affected for a range of different reasons.
Pathophysiology of Osteoarthritis
OA is a progressive and degenerative disease of the articular cartilage within joints. Articular cartilage is the smooth tissue that covers the ends of bones where they meet together at a joint. In animals with OA, there is a malfunction within the chondrocytes (cartilage cells). This means that the joint cannot work efficiently, it can cause changes in the synovial fluid. Synovial fluid is especially important for the joint as it provides nourishment to the cartilage, aids the absorption of force and lubricates the joint movement. The production of proteins that retain water within the cartilage is also lowered, leading to dehydration of the cartilage. This causes the destruction of the cartilage that surrounds the joint, leading to pain and inflammation as the underlying bone becomes exposed and the wear on the joint becomes abnormal. As the OA continues to progress, bone spurs and osteophytes can form because as the body attempts to repair the cartilage, it creates new bone material. Fibrosus and swelling can also occur all contributing to the stiffness and pain associated with OA.
Unfortunately, animals suffering from OA can enter a vicious circle as the body responds to the OA by decreasing function in an effort to prevent further damage and pain, leading to reluctance to exercise and loss of muscle strength. This means that the joints are less supported by the muscles leading to more pain and loss of function.
Causes of Osteoarthritis
OA can be classified into two groups:
Primary OA: Caused by age, gender, genetics, conformation, chronic repetitive trauma, or systemic predisposition.
Secondary OA: This can be caused by obesity, articular fracture, congenital abnormalities such as OCD and hip dysplasia, septic arthritis, or joint instability.
Symptoms of Osteoarthritis
Dogs:
Lameness
Reluctance to go on walks
Difficulties going up or down stairs, on/off sofa etc.
Stiffness after getting up from rest
Weight gain
Irritability or behavioural changes
Muscle wastage
Crepitus (popping or clicking of the joint)
Horses:
Lameness
Heat and/or swelling of a joint
Stiffness (worse after rest or in the cold)
Bony changes
Crepitus (popping or clicking of the joint)
Excessive laying down
Diagnosis
Radiographs or CT scans done by your vet can show changes within the joint. This alongside a lameness investigation, and physical examination can help to diagnose OA. Scintigraphy and MRI scans can also be performed.
Treatment Options
Medication:
Pain management should always be the first priority when managing OA. There is a range of pain medications available to suit the individual and whether the pain is acute or chronic in nature. In horses steroid injections into the joint can help to reduce ongoing inflammation. However, the advantages and disadvantages of such should be discussed with your vet. Other options may include platelet-rich plasma, arthroscopy, and stem cell therapy.
Remedial farriery:
Remedial farriery is also an option for horses depending on where the OA is located. This can help to alter the limb biomechanics to help distribute the forces through the joints more equally and improve ease of movement.
Surgery:
When a joint is severely affected by OA then surgery may be an option. An arthrodesis (fusion of the joint) can be very effective at treating the pain associated with OA. However, it does stop the joint from functioning, therefore it is considered as a salvage procedure and is more suitable for certain joints than others.
Physiotherapy:
Regular light-moderate controlled exercise, without concussive forces being put through the joints is key for OA management. Although it is individual for each animal, keeping an adequate amount of muscular support and preventing atrophy can help to provide joint stability and prevent further loss of function. Although the right balance should be met, the motion of the affected joints can encourage the production of synovial fluid within the joint aiding its function. A physiotherapist can prescribe exercise plans to help with the management of OA. Other therapeutic techniques including massage, electrotherapies (laser, PEMF, and hot and cold), and hydrotherapy can all help to reduce compensatory deficits, reduce pain and inflammation, and increase the available range of motion.
Environmental changes:
There are several environmental factors that can be considered when managing OA. For example in horses, this may be increasing turn out or having rubber matting in the stable. In dogs, it could be weight reduction, putting a rug down on slippery floors, or adding a ramp to get on and off the sofa etc. Another thing that can be considered is the use of joint supplements. This can be an area for debate, and your vet will have their own opinion on suitable joint supplements that they like. Most of them will contain Glucosamine and Chondroitin, with other potential ingredients being green-lipped mussels, MSM, ASUs, and Boswellia extract all having anti-inflammatory properties.
Prognosis
OA is a progressive condition, which means that it will continue long-term. Therefore, the goals of treatment will be to delay its progression, reduce pain, and restore function utilising a wide range of the treatment options listed above. The management of OA relies on teamwork from all paraprofessionals including the owner to get the best out of the treatment. When it is well managed, several animals are able to continue to live happily for many years after diagnosis!
If you have any questions or would like to contact us about physiotherapy for your animal, then please contact us!
Tel: 07527 310689
Email: info@arcvetphysio.co.uk
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