Osgood-Schlatter's disease Longitudinal meniscus tears of the patella Osgood-Schlatter's disease Recurrent dislocation of the patella Chondromalacia patellae Fat pad injury Rheumatoid arthritis Degenerative meniscus lesion Osteoarthritis
Infections are comparatively uncommon and occur in both sexes in all age groups.
Reiter's syndrome occurs in adults of both sexes; ankylosing spondylitis nearly always occurs in adult males. Both are comparatively rare.
Ligamentous and extensor apparatus injuries occur in both sexes, but are rare in children.
2. Find out if the knee swells. An effusion indicates the presence of pathology, which must be determined. (Note, however, that the absence of effusion does not necessarily eliminate significant pathology.)
3. Try to establish whether there is a mechanical problem (internal derangement) accounting for the patient's symptoms. Do this by:
(a) Obtaining a convincing history of an initiating injuiy. Note the degree of violence, and its direction. The initial incapacity is important. For example, a footballer is unlikely to be able to finish a game with a freshly torn meniscus. Note whether there was bruising or swelling after the injury, and whether the patient was able to weightbear.
(b) Asking if the knee 'gives way'. 'Giving-way' of the knee on going down stairs or jumping from a height follows cruciate ligament tears, loss of full extension in the knee, and quadriceps wasting. 'Giving-way' on twisting movements or walking on uneven ground follows many meniscus injuries.
(c) Asking if the knee 'locks'. Patients often confuse stiffness and true locking. Ask the patient to show the position the knee is in when and if it locks. Remember that the knee never locks in full extension. Locking due to a torn meniscus generally allows the joint to be flexed fully or nearly fully, but the last 10^0° of extension are impossible. Attempts to obtain full extension are accompanied by pain. Ask what produces any locking. With long-standing meniscus lesions a slight rotational force, such as the foot catching on the edge of a carpet, may be quite sufficient. In chronic lesions weightbearing is not an essential factor, locking not infrequently occurring during sleep. If the knee is not locked at the time of the patient's attendance, ask how it became free: unlocking with a click is suggestive of a meniscus lesion. Locking from a loose body may occur at varying positions of flexion. Locking from a dislocating patella may be noted to be accompanied by deformity.
(d) Asking about pain. Find out the circumstances in which it is present and ask the patient if he can localize it by pointing to the site with one finger.
In a high proportion of cases the likely diagnosis will have been established by this stage, requiring only confirmation by clinical examination.
Was this article helpful?