Rehabilitation of the older dog with osteoarthritis: workshop report

Osteoarthritis (OA) is a disease of joints characterised by changes in the component tissues that affect the joint's mechanical function. This can result in a reduction in the patient's ability to exercise and its quality of life. In this workshop delegates put together a clinical picture of the adult small animal patient with OA, and discussed the underlying problems in the disease along with methods of treatment, and rehabilitation (Figure 1 and 2). We focused on the physical aspect of rehabilitation, but discussed the other elements of therapy.

Delegates described their view of the patient or the clinical signs of OA as follows:

Patient type

• Purebred dogs, e.g. Labrador and GSD
• Working history and/or previous injuries
• Overweight
• Middle aged or older for dogs and the old or geriatric cat
• History of primary disease like hip dysplasia acknowledging that OA can start in the young patient.

Clinical signs

• Lameness, gait abnormality and poor posture
• Changed habits, behavioural and character changes
• Stiffness and morning stiffness
• Exercise intolerance and ‘laziness’
• Poor coat condition — cats
• Pain — especially at the limit of range of joint movement
• Condition worsens in the damp and cold
• Chronically swollen joint (fibrous thickening)
• Muscular weakness to wasting.

We went on to consider the pathological changes in OA. OA is often called a degenerative disease but in reality the changes are more varied than that. The most important changes seen in animal OA are:

• Loss of cartilage and exposure of underlying bone
• New bone formation at the margins of the joint with accompanying thickening of the joint capsule
• Underlying chronic inflammatory processes involved in tissue degeneration and pain
• [Changes in the synovial fluid consistency — not very significant in OA unlike other forms of arthritis].

Most of the clinical signs described by the delegates can be explained by the pathological changes or their consequences. Patients with an active arthritis lose their ability to exercise due to joint pain caused by the loss of cartilage and the chronic inflammation, and restriction of the range of movement (ROM) of the joint due to the new bone and fibrous tissue around the joint. These changes precipitate a downwards spiral in which the patient's reduction of exercise is perpetuated and its quality of life eroded (Figure 3).

Putting together a multimodal management plan for OA

Once a diagnosis of OA is made (normally on the basis of clinical signs with radiographic confirmation), a management plan can be discussed with the client. The key features of such a plan are

• The Target: a gradual increase in exercise, mobility and comfort
• Monitoring: regular checks to assess progress and modify treatment
• The Treatment: an appropriate selection of therapy
• The Timescale: this should be a therapy that evolves and changes as the patient improves.

As part of the initial examination a baseline for the points that will be monitored during treatment should be established. A useful list would be:

• Clients’ description of exercise, stiffness, lameness and pain, particularly of common activities, e.g. climbing stairs or jumping on furniture
• Estimation of degree of lameness or gait abnormality at walk and trot
• Physical examination — especially of affected joint especially
• Range of movement (ROM) (measure limits with goniometer)
• Pain
• Fibrous swelling.

Having a common form of recording or an ‘OA’ sheet in the practice for this sort of information is a very useful step in treatment as it makes progress easier to recognise.

First step — organise exercise

Exercising too much on damaged joints can exacerbate the signs of OA, so patients need an exercise plan that limits them to levels their joints can cope with. Many clients initially present their pets for OA because they perceive an increase in their clinical signs, or because a problem they have been aware of for a while has been ‘going on too long’. Thus it is often not possible to start directly with the target of increasing the patient's exercise/mobility, and the first part of the programme may be to organise a period of rest, followed by a controlled return to exercise. For dogs this normally involves increased time walking on the lead over 3 to 8 weeks, followed by a gradual re-introduction of off-lead exercise; for cats this may involve a strategic increase in freedom to use more rooms in a house before eventually being allowed outside. The next step is to decide how to facilitate increased mobility by using the sort of therapies illustrated in Figure 4.

Second step — weight control

Being overweight is a key problem in OA and for an overweight patient no single treatment is likely to have a bigger impact in the long term than weight loss. Clients need to be involved in weight loss and regular ‘weigh ins’, obesity or senior diets that have reduced calories, condition scoring and weight loss charts are all valuable tools. I'ts important that the client understands that significant improvement from other treatments is unlikely if their animal remains overweight.

Third step — pain control

It is important to control pain for the general welfare of the patient and to ensure that pain does not interfere with a gradual increase in mobility. The most common drugs used are the non-steroidal anti-inflammatories (NSAIDs), which despite their action against inflammation are most effective in OA in their analgesic role. It is important to remember that many OA patients suffer from chronic pain and so an analgesic strategy must take spinal sensitisation to pain into account requiring longer courses of analgesics and drugs such as gabapentin that target spinal pathways. Not every animal with OA will require analgesia and as other treatments progress every opportunity should be taken to re-assess the patient and to decide if analgesics can be reduced or discontinued.

Fourth step — physical therapy

It is impossible to describe all the physiotherapy techniques that could be applied to patients of this nature here. Physical therapy puts the therapist in direct contact with the patient so that therapy and monitoring are coupled. We demonstrated a set of simple techniques that can be introduced one after another, and taught to the client. They take the patient from simple analgesic effects and muscle stimulation, to proprioceptive learning as follows:

• Thermal therapy — warming over joint (very good before exercise) with microwaved wheat bags and chilling with cold packs
• Massage — (could focus on one joint, but often whole limb in the older arthritic that may have a number of problem joints)
• Effleurage: stroking one hand over another with no pressure over bony prominences for 5 mins per area
• Petrissage: kneading motion or circular movements over muscles letting fingers slip over the top of bony prominences
• Moving joint through a range of motion
• On feeling resistance wait until tension diminishes and then go on
• Move to bicycle motion for 10 reps
• Thoracic limb stretches — protraction and retraction get to the end feel and hold for 10 seconds 3–5 times once a day initially — tail off number of repetitions in programme later
• Similar stretches for pelvic limbs
• Assisted standing (Figure 5)
• Concentrate on getting the patient standing squarely
• Even load getting patient used to loading affected leg normally
• 30 secs to 1–2 mins
• Three leg standing all weight onto the affected limb (lift diagonal limb)
• Wobble cushion — extension of assisted standing
• Cavaletti poles — laid flat a body length apart (Figure 6)
• Progress to one end raised
• Walking through all of them or doing one gap at a time.

Fifth step — supplements

There are a wide variety of supplements available both in tablet/capsule form or as part of a proprietary diet. Although many supplements have little evidence available for their efficacy, over the last 10 years some quality evidence has emerged. The bulk of the positive evidence points towards supplementation with omega-3 fatty acids from marine sources and so it is definitely worth considering a supplement or nutraceutical with this as part of its formulation. As there is a great deal of variation in the formulation of nutraceuticals, it is worth researching the independent peer-reviewed literature when looking for a nutraceutical to use in your practice. A good start is the review by Vandeweerd et al (2012) which gives a good overview of formulations available up to 2011.

Sixth step — intervention

This covers intra-articular injections, stem cell therapy, platelet rich plasma therapy and a variety of surgical techniques. Most of these represent avenues of treatment that can be explored when more routine therapy fails to get the patient to a reasonable quality of life. Many of these ideas are new.

Summary

Many OA cases can be managed with the multi-modal application of a number of simple techniques. There is a high premium on carefully repeating basic examination, simple monitoring and on communicating the priorities in treatment to the client. Many patients can be treated without recourse to invasive procedures or complex and cumbersome equipment. So it is realistic to believe that many practices could do much of their OA management through a nurse or physiotherapist-led clinic.