Osteoarthritis is often described as “wear and tear” in the joints. It is not an inflammatory condition like rheumatoid arthritis. The –itis ending is misleading. It occurs in the synovial joints and is a result of a combination of genetic factors, overuse and injury.
Risk factors include obesity, age, occupation, trauma, being female and family history.
It is thought to be the result of an imbalance between the cartilage being worn down and the chondrocytes repairing it leading to structural issues in the joint. These abnormalities can be seen on an xray:
Four Key Xray Changes (LOSS)
- L – Loss of joint space
- O – Osteophytes
- S – Subchondral sclerosis (increased density of the bone along the joint line)
- S – Subchondral cysts (fluid-filled holes in the bone, aka geodes)
Xray changes do not necessarily correlate with symptoms. Significant changes might me found incidentally on someone without symptoms. Equally, someone with severe symptoms of osteoarthritis may have only mild changes on an xray.
Osteoarthritis presents with joint pain and stiffness. This pain and stiffness tends to be worsened by activity in contrast to inflammatory arthritis where activity improves symptoms. It also leads to deformity, instability and reduced function in the joint.
Commonly Affected Joints
- Sacro-iliac joints
- Distal-interphalangeal joints in the hands (DIPs)
- The MCP joint at the base of the thumb
- Cervical spine
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 carpo-metacarpal joint
- Weak grip
- Reduced range of motion
The carpo-metacarpal joint at the base of the thumb is a saddle joint with the metacarpal bone of the thumb sat on the trapezius bone like a saddle. It gets a lot of use from everyday activities. This makes it very prone to wear when used for complex movements.
NICE (2014) suggest that a diagnosis can be made without any investigations if the patient is over 45, has typical activity related pain and has no morning stiffness or stiffness lasting less than 30 minutes.
Start with patient education about the condition and advise on lifestyle changes such as weight loss if overweight to reduce the load on the joint, physiotherapy to improve strength to support the joint and occupational therapy and orthotics to support activities and function.
Stepwise use of analgesia to control symptoms:
- Oral paracetamol and topical NSAIDs or topical capsaicin (chilli pepper extract).
- Add oral NSAIDs and consider also prescribing a proton pump inhibitor (PPI) to protect their stomach such as omeprazole. They are better used intermittently rather than continuously.
- Consider opiates such as codeine and morphine. These should be used cautiously as they can have significant side effects and patients can develop dependence and withdrawal. They also don’t work for chronic pain and result in patients becoming depending without benefitting from pain relief.
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.
Last updated March 2019