Diagnosis (Page 1 of 2)

There are multiple guidelines available that provide information on the assessment and management of osteoarthritis. (for example, RACGP 2018, NICE 2014, Victorian Model of Care for osteoarthritis of the Hip and knee 2018, Australian Clinical Care Standard (ACSQHC) for Knee OA 2017). All these guidelines suggests that:

“Plain radiograph is not required to make a diagnosis of hip and knee osteoarthritis, but could be considered for atypical presentations”

However, the Australian Orthopaedic Association has declined to endorse the current ACSQHC Osteoarthritis of the Knee Clinical Standard, as it does not support the use of x-rays as a diagnostic tool.

To clinically diagnose an individual with knee OA they must satisfy these criteria:

They must also have any one or more of these:

Whilst the prevalence of knee OA is higher, the prevalence of hip OA is still estimated to be at 28% in people over the age of 45 years old.

Groin pain is considered the most commonly reported symptoms, but there can also eb referral pain to the buttock, thigh (particularly lateral), distal leg and knee. 

The prevalence of knee pain caused by hip OA is currently unknown. Most literatures are related to case studies (including examples of patients having undergone revision TKR as knee pain remained – with knee pain subsequently resolved after a THR).

Below you will see 2 clinical prediction rules for hip osteoarthritis. Click on each black tab to see the information.

During your consultation, consider your patient’s history of trauma (such as MVA, or falls) as a possible cause of pain. Also be aware of osteoporosis, or risk of osteoporosis (e.g., in postmenopausal women) and assess for hematoma, oedema and significant pain. Soft tissue injuries (quadriceps or patellar tendon ruptures, ligamentous injuries) and fractures of the knee and neck of femur can also be possible causes of pain.

When considering whether you need to image your patient’s knee, remember the Ottawa knee rules. These are the indications for a knee x-ray:

Patients who do not meet the criteria are highly unlikely to have clinically significant fractures and can have knee imaging safely deferred.

Consider the possibility of referred pain from the spine particularly if there is history of back pain.

Presence of pins and needles or numbness may suggest radicular symptoms

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AG: Yes-will expand on this

Radicular pain 

May also be associated with weakness, however can be difficult to differentiate whether weakness related to pain, disuse atrophy or neurological.

Checking knee extension reflex may assist in differentiating between a radiculopathy and other sources of wekaness.

Slump  to be expanded on

Distinguishing whether the pain in your patients hip is coming from the joint itself, or from the lumbar spine can sometimes be challenging.

Here are some statistics to help you ascertain the source:

• Patients with a limp are 7 times more likely to have hip or hip + lumbar spine component to the problem than lumbar spine disorder alone
• Patient with groin pain is 7 times more likely to have hip or hip + lumbar spine component than lumbar alone.
• Painful and limited internal rotation are key clinical predictor of hip pathology. These individuals are 14 times more likely to have hip pathology than lumbar. This is recognized by various guidelines in diagnosing hip OA
• Weakness in hip abductors may be an indication of L4/L5 involvement (as they supply gluteus medius). Assessing the patients walking on their heels/toes can be a way of assessing myotomal weakness if there is suspicion of lumbar component.
• Pain when weightbearing on the affected side may suggest that the source of pain may be from the hip.

Inflammatory arthropathies includes rheumatoid arthritis and psoriatic arthritis.

Psoriatic arthritis is present in 20-25% of people with psoriasis; and has an overall prevalence of 1-2 per 1000 people.

• Approximately 70% of people with psoriatic arthritis will have psoriasis
• Involvement in the distal interphalangeal joints can be present in psoriatic arthritis or OA, however presence of Heberden’s nodules is characteristic of OA.
• In contrast, RA typically affects metacarpal phalangeal and proximal interphalangeal joints 

Rheumatoid arthritis (RA) is associated with soft, warm, ‘boggy’ and tender joints; whereas swelling of OA joints is often hard and bony. RA is typically in the peripheral joints rather than in the lower back.
It is suspected when

• There is inflammatory arthritis involving 3 or more joints
• Positive RF and anti CCP testing
• Elevated CRP or ESR
• Symptoms lasting more than 6 weeks.
• Morning stiffness lasting longer than 30 minutes
• Other inflammatory symptoms are excluded.

Below you will find a table summarising the characteristics of psoriatic arthritis and RA

Gout is a common form of inflammatory arthritis that usually affects one joint at a time (often it is the big toe joint). It is caused by hyperuricemia, where there is access uric acid in the body. When there is too much uric acid in the body and it is not broken down, it is deposited in the joints, fluids and tissues within the body.

• Gout affects approximately 1% of the population.
• It is more common in males than females, and those who are middle aged (>40 years old)
• Some risk factors include obesity, alcohol use, have renal impairment, hypertension, and/or currently taking diuretics.

Pseudogout is another form of inflammatory arthritis – it is a metabolic monoarthropathy. It has many symptoms that are similar to gout, including the sudden onset of severe pain, swelling, warmth, and redness in a joint. It is caused when calcium pyrophosphate dihydrate (also called CPPD) accumulate in joints. The term acute CPP crystal arthritis is now often the preferred term in place of pseudogout

• It is more common in elderly females than males
• It is associated strongly with OA and acute synovitis
• Knees are the most common joint to be affected, however it can affect any joint.

Chrondrocalcinosis is radiographic calcification in hyaline and/or fibrocartilage. It often presents with pseudogout or CPPD disease. However it is not always there and neither is is specific to CPPD disease. Patients can be asymptomatic even though chondrocalcinosis might be present on their x-rays.

On the right you will see an x-ray with chrondrocalcinosis involving both the meniscal fibrocartilage and hyaline cartilage of the femoral condyles. 

Below is a table comparing both gout and pseudogout.