The baby boomers are a generation that grew up exercising and now expects, indeed demands, that they be able to continue to exercise into their 70's. Unfortunately, evolution does not work that quickly. Physically, a 50 year-old can not necessarily do what they did at 25. The warranty on some of the body parts has worn out. One of the conditions now most commonly seen is hip and knee arthritis. Although it is not the most common type of osteoarthritis, it is probably the most debilitating and has now developed the coined term "boomeritis" in those patients born between 1946 and 1964.
This arthritis occurs when the normal relationship between the synovium, articular cartilage and subchondral bone is altered. With age, the lubricating properties of synovial fluid is reduced from decreased water content causing articular surface destruction. Large weight bearing joints such as the knee and the hip can have three times the body weight in joint reactive forces. Patients complain of pain, stiffness, limited range of motion, and swelling. The pain is often described as achy, associated with activity. Occasionally, the pain may be sharp and worse at night after the patient has stopped activity.
Physical examination of the knee often reveals a boggy synovitis and swelling, palpable crepitus, and pain at the extremes of motion, flexion contracture and an obvious mal-alignment is not uncommon. With hip arthritis, pain restricted range of motion, internal less than external, is usual and patients may present complaining of knee pain. In these cases, an antalgic gait with the affected hip rising higher than the other is typical. The most common gait abnormality in knee arthritis is a lateral thrust associated with a varus angular deformity.
X-rays are useful in quantifying the severity of the arthritis. Mild changes such as joint space narrowing denote early arthritis. Osteophytes, the body's attempt to distribute mechanical stress across the joint, and subchondral sclerosis signify more moderate changes. Bone on bone apposition, subchondral cyst formation, joint erosions, and occasionally joint subluxation represent end stage x-ray changes. Significant hip arthritis is sometimes manifested by severe medial joint space narrowing without severe superior narrowing.