Knee examination

Knee Examination is a critical component of the musculoskeletal assessment, aimed at diagnosing injuries and conditions affecting the knee joint and surrounding structures. It involves a systematic approach that includes patient history, visual inspection, palpation, and functional testing. The knee examination can identify issues such as ligament tears, meniscal injuries, and arthritis.

History

The initial step in a knee examination involves taking a comprehensive history from the patient. This includes understanding the mechanism of injury, location of pain, duration of symptoms, and any previous knee injuries or surgeries. Key questions may focus on the onset of pain, its nature (sharp, dull, constant, intermittent), and any activities or movements that exacerbate or relieve the pain.

Inspection

Inspection of the knee begins with the patient in a standing position, allowing the examiner to assess alignment, swelling, and any visible deformities. The examiner looks for signs of atrophy or hypertrophy of the quadriceps muscle, which may indicate chronicity of knee pathology. The skin around the knee is also inspected for scars, rashes, or signs of infection.

Palpation

Palpation involves the examiner using their hands to feel the knee structures. Key landmarks such as the patella, tibial tuberosity, joint line, and ligaments (medial and lateral collateral ligaments, anterior and posterior cruciate ligaments) are palpated to assess for tenderness, warmth, or irregularities. This can help localize the source of knee pain.

Range of Motion

The range of motion (ROM) of the knee is assessed both actively (patient moves the knee) and passively (examiner moves the knee). Normal knee ROM is from 0 degrees (full extension) to about 135 degrees of flexion. Limitations in ROM can indicate joint effusion, ligamentous injury, or arthritis.

Special Tests

Several special tests are integral to the knee examination, each designed to isolate specific structures for assessment:

• Lachman Test: Assesses the integrity of the anterior cruciate ligament (ACL).
• Pivot Shift Test: Also tests for ACL integrity, focusing on anterolateral rotational instability.
• McMurray Test: Used to evaluate meniscal tears.
• Apley's Test: Differentiates between meniscal and ligamentous injuries.
• Patellar Apprehension Test: Assesses for patellar instability.

Functional Assessment

Functional assessments may include observing the patient's gait, ability to squat, and perform a single-leg stance. These activities can provide information on the knee's functional stability and pain during movement.

Conclusion

A thorough knee examination is essential for diagnosing knee injuries and conditions accurately. It should be performed systematically, incorporating history, inspection, palpation, range of motion, special tests, and functional assessment. Following the examination, further diagnostic imaging (e.g., X-ray, MRI) may be warranted based on the findings.