This clinical mind map is organized based upon the duration and then the location of the pain. Several causes of acute pain are related to injury, which often is acute trauma, but also can be from chronic overuse. The lack of concordance between “acute” tissue injuries secondary to “chronic” overuse does not necessarily make intuitive sense. In addition, patients with classic chronic conditions do not always present after several weeks of having pain. Instead a patient may seek help very early on in the process. In contrast, some patients with acute injuries adopt a wait and see approach, hoping to get better, and may not seek help for several weeks. Therefore, a clinician must ask questions about onset, activities, and use/overuse injuries, in addition to the high yield questions (duration, location), to be able to differentiate among all conditions accurately. Meniscal injury can present with pain in a sudden as well as a gradual way and is listed under both acute and chronic conditions.
Conditions such as aseptic arthritis, SCFE (slipped capital femoral epiphysis) and severe trauma can lead to significant morbidity or disability. However, several additional conditions can cause long term disability, such as severe Osteoarthritis, Rheumatoid Arthritis, and Osteochondritis Dessicans, but these conditions evolve in a more gradual manner, and the disease progression depends on factors in addition to the underlying pathology.
An easy way to memorize probable diagnoses for both acute and chronic knee pain is to think about five compartments (anterior, posterior, medial, lateral, overall) and their associated pathology.
In order to memorize probable diagnoses for posterior knee pain, a clinician can remember 2 conditions for the young, 2 for athletic youth, 2 for the stressed, 2 for casual workers and 2 for older adults.
Vital signs, the patient’s appearance and the history of trauma must be reviewed to address urgent/emergent situations. A clinician must gather an accurate history and physical exam findings in order to weigh and remove anchor bias. The knee joint contains several structures, and due to the complex anatomy of the joint, patients may not be able to accurately describe the location of the pain and the associated features. Therefore, when localizing the origin of pain, a clinician must attempt to be as precise as possible. SCFE may pose itself as a diagnostic dilemma where the origin of pathology is in the hip but the patient complains about knee pain, which places the clinician at risk for missing the diagnosis. Therefore, the clinician must keep this localizing challenge in mind, especially when evaluating pediatrics, and should not prematurely close the encounter until after a thorough history and physical exam of the entire lower extremities.