Brush Test (Stroke or Wipe Test)

The Brush Test, also known as the Stroke or Wipe Test, is a valuable clinical tool used to assess minimal effusion in the knee joint.

What Is the Brush Test?

The Brush Test is a physical examination maneuver designed to detect even minimal effusions in the knee joint. It involves manipulating the knee in specific ways to observe the movement of synovial fluid, thereby identifying the presence of effusion.

See Also: Patellar Tap Test

Why the Brush Test Matters

Identifying effusion early can be critical in diagnosing underlying knee conditions such as osteoarthritis, rheumatoid arthritis, or knee injuries. The test is quick, non-invasive, and highly sensitive to minimal joint effusion.

How to Perform the Brush Test

Positioning the Patient: The patient lies supine with the knee extended.

Smoothing the Medial Side: Using one hand, smooth the medial side of the knee from distal to proximal. This action attempts to displace the synovial fluid to the superior recess.

Pressing the Superior Recess: With the other hand, apply gentle pressure on the superior recess, moving distally from a proximal and lateral position. This maneuver aims to push the synovial fluid back towards the medial and distal part of the knee joint.

Observing the Fluid Wave: Observe the medial side of the knee for a visible wave of fluid. Even with mild effusion, a wave may be observed in the distal, medial part of the joint.

Clinical Relevance of the Brush Test

A positive Brush Test indicates joint effusion, prompting further investigation into the underlying cause. This may involve imaging studies, aspiration, or laboratory tests to determine the exact pathology.

Conclusion

The Brush Test is a valuable, simple, and effective diagnostic tool for orthopedic professionals. Its sensitivity to minimal effusion can lead to early detection and timely intervention for various knee joint pathologies. Incorporating this test into regular knee assessments can significantly improve patient outcomes in clinical practice.

References & More

1. Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.
2. Clinical Tests for the Musculoskeletal System 3rd Edition.
3. Clinical Assessment and Examination in Orthopedics, 2nd Edition Book
4. Rutherford DJ, Hubley-Kozey CL, Stanish WD. Knee effusion affects knee mechanics and muscle activity during gait in individuals with knee osteoarthritis. Osteoarthritis Cartilage. 2012 Sep;20(9):974-81. doi: 10.1016/j.joca.2012.05.014. Epub 2012 Jun 12. PMID: 22698444. Pubmed