Hello Surgeon

X

How can we help you today?

Special Test

Knee Effusion Tests

Knee Effusion is fluid accumulation in the intra-articular space of the knee joint. Knee Effusion Tests are used to evaluate the presence and amount of this effusion.

See Also: Knee Ligaments Anatomy

Knee Effusion Tests

The Knee Effusion Tests include:

  1. Patellar tap test
  2. Fluctuation test
  3. Stroke test
  4. Ballottement Test
  5. Dancing Patella Test
  6. The Bulge Test.

Patellar tap test

With patient supine, examiner presses suprapatellar pouch and then taps on patella. Patella remains in contact with femur if no swelling is present.

See more for Patellar tap test.
Patellar tap test

Fluctuation test

With patient supine, The knee is extended, and the quadriceps are relaxed. The examiner places thumb and finger around patella while pushing any fluid from suprapatellar pouch with other hand.

Fluctuation test is positive if finger and thumb are pushed apart.

Fluctuation test

Stroke Test

The patient is supine and has knee in full extension. Starting at the medial tibiofemoral joint line, the examiner strokes upward two or three times toward the suprapatellar pouch in an attempt to move the swelling within the joint capsule to the suprapatellar pouch. The examiner then strokes downward on the distal lateral thigh, just superior to the suprapatellar pouch, toward the lateral joint line.

Stroke test is positive if fluid is observed on the medial side of the knee and quantified using a 5-point scale.

knee Stroke Test

A study on 75 patients referred to an outpatient physical therapy clinic for treatment of knee dysfunction for which effusion testing was deemed appropriate by the treating therapist, the Interexaminer Reliability for this test was κ = 0.64 (0.54, 0.81).

Stroke Test Grading Scale

GradeTest Result
ZeroNo wave produced on downstroke
TraceSmall wave on medial side with downstroke
1+Larger bulge on medial side with downstroke
2+Effusion spontaneously returns to medial side after upstroke (no downstroke necessary)
3+So much fluid that it is not possible to move the effusion out of the medial aspect of the knee

Knee Ballottement test

Examiner quickly pushes the patient’s patella posteriorly with two or three fingers. Positive if patella bounces off trochlea with a distinct impact.

A study on 134 patients with traumatic knee complaints, the sensitivity and specificity of the Ballottement test was 83% and 49% respectively.

Knee Ballottement test

The Bulge Test

This test is helpful in cases with very little fluid in the knee joint. After squeezing, any fluid out of the supra patellar pouch, the medial compartment of the joint is emptied by pressing on the inner aspect of the joint; that hand is then lifted away and the lateral side is sharply compressed to see a distinct ripple on the flattened medial surface as fluid is shunted across.

References

  1. Sturgill LP, Snyder-Mackler L, Manal TJ, Axe MJ. Interrater reliability of a clinical scale to assess knee joint effusion. J Orthop Sports Phys Ther. 2009 Dec;39(12):845-9. doi: 10.2519/jospt.2009.3143. PMID: 20032559.
  2. Fritz JM, Delitto A, Erhard RE, Roman M. An examination of the selective tissue tension scheme, with evidence for the concept of a capsular pattern of the knee. Phys Ther. 1998 Oct;78(10):1046-56; discussion 1057-61. doi: 10.1093/ptj/78.10.1046. Erratum in: Phys Ther 1998 Dec;78(12):1339. PMID: 9781699.
  3. Kastelein M, Luijsterburg PA, Wagemakers HP, Bansraj SC, Berger MY, Koes BW, Bierma-Zeinstra SM. Diagnostic value of history taking and physical examination to assess effusion of the knee in traumatic knee patients in general practice. Arch Phys Med Rehabil. 2009 Jan;90(1):82-6. doi: 10.1016/j.apmr.2008.06.027. PMID: 19154833.
Last Reviewed
May 23, 2022
Contributed by
OrthoFixar

Orthofixar does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice.

Angle Meter App for Android & iOS
  • Lifetime product updates
  • Install on one device
  • Lifetime product support
One-Click Purchase
Orthopedic FRCS VIVAs Quiz
  • Lifetime product updates
  • Install on one device
  • Lifetime product support
One-Click Purchase
Top 12 Best Free Orthopedic Apps
  • Lifetime product updates
  • Install on one device
  • Lifetime product support
One-Click Purchase
All-in-one Orthopedic App
  • Lifetime product updates
  • Install on one device
  • Lifetime product support
One-Click Purchase