ESSENTIALS OF DIAGNOSIS
History is most important in diagnosing musculoskeletal problems.
The mechanism of injury can explain the pathology and symptoms.
Determine whether the injury is traumatic or atraumatic, acute or chronic, high or low velocity (greater velocity suggests more structural damage), or whether any movement aggravates or relieves pain associated with the injury.
Musculoskeletal problems account for about 10–20% of outpatient primary care clinical visits. Fifty-three percent of adults older than 65 years complain of bothersome pain each month usually with multiple sites of pain and decreased physical function. Orthopedic problems can be classified as traumatic (ie, injury-related) or atraumatic (ie, degenerative or overuse syndromes) as well as acute or chronic. The history and physical examination are sufficient in most cases to establish the working diagnosis; the mechanism of injury is usually the most helpful part of the history in determining the diagnosis. The onset of symptoms should be elicited. With acute traumatic injuries, patients typically seek medical attention within 6 weeks of onset. The patient should describe the exact location of symptoms, which helps determine anatomic structures that may be damaged. If the patient is vague, the clinician can ask the patient to point with one finger only to the point of maximal tenderness.
The chief musculoskeletal complaints are typically pain (most common), instability or dysfunction around the joints. Since symptoms and signs are often nonspecific, recognizing the expected combination of symptoms and physical examination signs can help facilitate the clinical diagnosis. Patients may describe symptoms of "locking" or "catching," suggesting internal derangement in joints. Symptoms of "instability" or "giving way" suggest ligamentous injury; however, these symptoms may also be due to pain causing muscular inhibition. Constitutional symptoms of fever or weight loss, swelling with no injury, or systemic illness suggest medical conditions (such as infection, cancer, or rheumatologic disease).
Typical evaluations in the clinic follow the traditional components of the physical examination and should include inspection, palpation, and assessment of range of motion and neurovascular status.
Inspection includes observation of swelling, erythema, atrophy, deformity, and (surgical) scars (mnemonic, "SEADS"). The patient should be asked to move joints of concern (for example, see Table 41–1). If motion is asymmetric, the clinician should assess the passive range of motion for any physical limitation.
There are special tests to assess each joint. Typically, provocative tests recreate the mechanism of injury with the goal to reproduce the patient's pain. Stress tests apply load to ligaments of concern. Typically, 10 to 15 pounds of force should be applied when performing stress tests. Functional testing, including simple tasks performed during activities of daily living, is useful to assess injury severity.