Osteoarthritis Flashcards
What is osteoarthritis?
Osteoarthritis is often described as “wear and tear” in the joints. It is not an inflammatory condition like rheumatoid arthritis. It occurs in the synovial joints and results from a combination of genetic factors, overuse and injury.
Osteoarthritis is thought to result from an imbalance between the cartilage wearing down and the chondrocytes repairing it, leading to structural issues in the joint.
What are the risk factors of osteoarthritis?
Risk factors include obesity, age, occupation, trauma, being female and family history.
What are the commonly affected joints?
Hips
Knees
Sacro-iliac joints
Distal-interphalangeal joints in the hands (DIPs)
The carpometacarpal joint at the base of the thumb (CMC)
Wrist
Cervical spine (cervical spondylosis)
Four Key X-ray Changes (LOSS)
L – Loss of joint space
O – Osteophytes (bone spurs)
S – Subarticular sclerosis (increased density of the bone along the joint line)
S – Subchondral cysts (fluid-filled holes in the bone)
Presentation
Osteoarthritis presents with joint pain and stiffness. The pain and stiffness tends to be worse with activity and at the end of the day, in contrast to inflammatory arthritis, where activity improves symptoms and the symptoms tend to be worse first thing in the morning. Osteoarthritis leads to deformity, instability and reduced function of the joint.
General signs of osteoarthritis are:
Bulky, bony enlargement of the joint
Restricted range of motion
Crepitus on movement
Effusions (fluid) around the joint
Signs in the Hands
Heberden’s nodes (in the DIP joints)
Bouchard’s nodes (in the PIP joints)
Squaring at the base of the thumb at the carpometacarpal joint
Weak grip
Reduced range of motion
The carpometacarpal joint at the base of the thumb is a saddle joint, with the thumb’s metacarpal bone sat on the trapezius bone, using it like a saddle. It gets a lot of use from everyday activities, making it very prone to wear.
Diagnosis
The NICE guidelines (updated 2020) suggest that a diagnosis can be made without any investigations if the patient is over 45, has typical pain associated with activity and has no morning stiffness (or stiffness lasting under 30 minutes).
Management
Weight loss if overweight to reduce the load on the joint
Physiotherapy to improve strength and function
Occupational therapy to support activities and function (e.g., special devices and adaptations to the home)
Orthotics to support activities and function (e.g., knee braces)
The use of analgesia involves a stepwise approach to control symptoms:
Oral paracetamol and topical NSAIDs
Add oral NSAIDs (consider co-prescribing a proton pump inhibitor, such as omeprazole, to protect the stomach)
Consider opiates such as codeine
Topical capsaicin (chilli pepper) cream may be helpful, where available.
Intra-articular steroid injections provide a temporary reduction in inflammation and improve symptoms.
Joint replacement can be used in severe cases. The hip and knee are the most commonly replaced joints.
Side effects of NSAIDS
NSAIDs (e.g., ibuprofen or naproxen) are very effective for musculoskeletal pain. However, they need to be used with caution, particularly in older patients and those on anticoagulants, such as aspirin or DOACs. They are better used intermittently, for a short time to get the pain under control, rather than continuously. They have several potential adverse effects, including:
Gastrointestinal side-effects, such as gastritis and peptic ulcers (leading to upper GI bleeding)
Renal side-effects, such as acute kidney injury (e.g., acute tubular necrosis) or progressive kidney disease
Cardiovascular side-effects, such as hypertension, heart failure, myocardial infarction and stroke
Exacerbating asthma
Opiates should be used cautiously, as they can have significant side effects, and patients can develop tolerance, dependence and withdrawal symptoms. There is minimal evidence that they work for chronic pain. They often result in patients becoming dependent without benefitting from pain relief.
