What is the easiest thing about diagnosing knee and hip OA?  

For any condition, the history is usually key for diagnosis and this holds true for OA. There is usually a classic pain history and the presence of risk factors.  

What is the hardest thing about diagnosing knee and hip OA?

I personally find I have more uncertainty diagnosing hip OA. You cannot palpate the joint line. The pain is sometimes vague in location and can be referred to the knee. There are many other conditions that can cause hip pain.

Is a patient history and physical examination usually sufficient for you to diagnose knee or hip OA?

Usually, yes. The pain history is characteristically of gradual onset and worse with weight-bearing activities. There is an absence of significant stiffness. Pain at rest and at night becomes present in more advanced disease.

I assess for risk factors such as advancing age, female gender, obesity, family history of OA and previous joint injuries, work or sports that have placed repetitive stress on joints.

On examination of the knee, I look for malalignment such as genu varum which puts extra strain on the medial knee compartment. There may be bony enlargement (osteophytes) in the knee joint, joint line tenderness, crepitus and reduced ROM. I would expect an absence of warmth and erythema.

In the hip I palpate to exclude tenderness over other structures such as the gluteal muscles or the greater trochanter. An early sign of OA is a loss of internal rotation during hip flexion.

In typical presentations, are X-rays and MRI required to diagnose OA?

I try to be judicious in my use of imaging. In the absence of atypical features, imaging is not usually required. In mild to moderate disease, imaging will not generally change management. I order imaging for atypical presentations or for advanced disease when considering the need for orthopaedic intervention.

Do you feel under pressure to refer for imaging to diagnose OA?

Patients frequently have an expectation of imaging. I find that in general, not just for OA, patients expect that an investigation is required for diagnosis. They sometimes request an MRI over an X-ray when it is not needed. Patients who have had demonstrated OA on imaging will sometimes request serial imaging to just ‘see how it is going, I haven’t had any X-rays for a while’.

I discuss that imaging is only needed if it is likely to change our management. I try to dissuade them from imaging when it’s not necessary by advising them it is ‘a dose of radiation that you don’t need’.

Do you recommend weight loss as a core treatment for overweight or obese patients with OA?

Absolutely. Even small amounts of weight loss can reduce pain in OA. Studies have shown that even 6 kg of weight loss can reduce pain in knee OA.

Weight loss can slow the progression of OA and delay the need for a joint replacement. If joint replacement can be delayed, then there is a better chance they will not require a revision. Revisions have poorer outcomes.

For this reason, I particularly stress the benefits of weight loss to patients with obesity who have presented with early presentation arthritis.

Is it difficult to raise the issue of weight loss with them?

It certainly needs to be done sensitively. I avoid the term ‘obese’ where possible due to the stigma around this term. I prefer terms such as ‘a healthy weight’ or ‘carrying excess weight’.

The exception for this is in communicating with those who do not recognise that they have obesity and need to have this clearly explained. In my personal experience, this is more often the case for men.

I would say the difficulty is not so much raising the issue of weight loss but encouraging patients to attempt weight loss. Often patients with obesity have attempted weight loss many times. Frequently they have lost weight only to put it on again, plus more. They can feel disempowered to attempt weight loss again.  

How successful are you at managing weight loss in your patients with OA?

It is quite variable. It depends very much on the patient’s readiness to change. Pain can be a motivator to take action. For patients who do not yet want to attempt weight loss, I suggest that in the meantime aiming for weight maintenance would be a great goal. Many patients are slowly and steadily putting on weight.

What limits your success with them?

Weight loss induces a very strong hormonal response which increases hunger and leads to weight regain. The body strongly protects excess weight. I advise that weight loss is hard but maintaining weight loss is even harder. For this reason we need to plan ahead for relapses and have an action plan.

What helps you most with having success with managing weight loss with them?

Having an existing strong therapeutic relationship with patients. Being non-judgmental. Empathising that weight loss is hard. Discussing that there is a strong genetic component to weight gain to help reduce their guilt and shame.

I avoid the phrase ‘going on a diet’ as it may have past negative connotations and it also sounds like a temporary change. I emphasise ‘healthy eating’ or ‘lifestyle change’ which sound more like ongoing changes.

I listen to what they have tried in the past - what has worked for them and what led to relapses. There are many successful approaches to weight loss, excluding crazy fad diets, so it is helpful to be familiar with some of these to discuss. They usually have an idea of an approach that will work for them best in their current situation. I say that the plan they can best stick to is the best one for them.

Whatever approach they use, trying to reduce rebound hunger is key. I suggest increasing their protein to help increase satiety. I suggest they aim to have at least five serves of vegies a day, particularly vegetables with lower calorie density. These will make them feel fuller due to the volume of food and fibre. I suggest looking at the Mediterranean diet as it has additional benefits of reducing cardiovascular risk and involves a high vegetable intake.

We discuss mindful eating. I ask them if they are emotional eaters and suggest they try to become aware of their cues and develop other ways of responding.

I suggest they make goals of what they can do rather than a number on a scale, for example, start with three thirty-minute walks this week.

I celebrate small successes and lifestyle changes with them. I think GPs are well placed to offer helpful advice around weight loss and to act as a coach.  

What things would improve your success as a GP with managing weight loss?

I would suggest a longer initial appointment for making a plan and more frequent follow-up appointments for coaching. Too long between appointments can reduce the impetus to act. I work in a privately billing clinic and I am mindful of the cost to the patient.

I think it would be great to have more research around how GPs can most effectively support our patients to lose weight.

Success with managing weight loss is a holy grail in medicine for me. Excess weight is the cause of so many preventable conditions. With the current challenges in managing weight loss, preventing weight gain is so important.