Management Of A Painful Joint " Part Two "
If the pain is judged as coming from the joint in question then certain decisions have to be made as to the causes of this. Inflammatory arthritis is the first category to be considered, with inflammatory changes affecting the the synovial membranes and the entheses, the junctions between the bones and the ligaments and tendons. Non-inflammatory arthritis involves changes in the structure and function of the joint, occurring as damage to the menisci or the articular cartilage lining the joint or secondary to changes in the joint which can be from a variety of causes.
The third possibility is joint pain or arthralgia in the absence of significant pathology, such as fibromyalgia or with sub clinical changes that have yet to declare themselves. Different types of joint disorders can occur in the same joint with inflammatory disorders typically destabilising a joint and leading to structural abnormality. Pain is a significant symptom of these joint disorders and in inflammatory conditions the pain is present whether the joint is moving or still, with it typically being worse as the movement is started. With arthritic changes that are not secondary to inflammation pain occurs typically with movement and improves with resting.
If the vertebral column or the large joints suffer from significant degenerative changes they may give pain when resting and at night, disturbing sleep. It is less easy to localise accurately the pain from larger joints as compared to smaller ones, with the hip being an example of how pain can be referred to several areas including the fronts of thighs, the groin, the side of the hip and the buttock. Patients perceive difficulty moving a joint, especially when just getting going, as stiffness and this symptom is usually better once the joint has got going and worse again after a rest period. Normal joint stiffness lasts 10-15 minutes but inflammatory stiffness may be for an hour or longer.
Joints often exhibit swelling which can occur in several different ways. In inflammatory disease excessive fluid is secreted by the synovial lining of the joint, causing an effusion which is a collection of fluid within a joint cavity, capable of being drawn off with a needle. Osteoarthritic or other non-inflammatory changes respond by forming bony outgrowths at the joint margins which make the joint enlarge in a knobbly fashion. Loss of some of the joint's movement is common either from inflammation and pain, damage to the structure of the joint or soft tissue contracture.
Activities of daily living are often affected by arthritic change such as dressing, self care and stair climbing, often secondary to muscle weakness and atrophy. If pain accompanies weakness the cause is likely musculoskeletal rather than neurological or due to muscle pathology. Weakness can cause functional problems such as gripping things, getting up and down from sitting or walking safely. In systemic arthritis the whole person is involved in the disease and malaise and fatigue are common. An arthritis can develop slowly or can come on quickly, joint symptoms occurring over a few hours, in response to injury, infection or crystal deposition.
The symmetry of joint involvement varies with different types of disease. Symmetrical involvement, typical of systemic lupus erythematosus and rheumatoid arthritis, attacks the same joints on both sides of the body. Asymmetrical involvement, more typical of psoriatic arthritis and reactive arthritis, shows varying joints affected on each side of the body. Different patterns of joint involvement occur in varying conditions, with finger end joints affected in gout, psoriatic arthritis and osteoarthritis but not rheumatoid arthritis.