Importance of Knee Pain Tests for Diagnosis

Can understanding what knee tests are used help a healthcare provider diagnose the cause of individuals experiencing knee pain?

Knee Pain Tests

A knee examination is the first step in determining the cause of knee pain. Different knee tests may be performed during the exam to help the healthcare provider find the cause and develop an optimal treatment plan. These tests evaluate knee function and range of motion and look for conditions and injuries such as arthritis, meniscus tears, ACL tears, other ligament injuries, and kneecap issues.

Checking If There is Fluid in the Knee

Many individuals know if their knee is swollen, as they can see or feel the swelling. However, if there is excess fluid in the knee joint, the healthcare provider may compress the joint to feel for excess fluid. Fluid is often visible above the kneecap and can be compressed in this area. Fluid may also be detected in the back of the knee, referred to as a Baker’s cyst if the fluid has collected into a cluster. (Frush T. J., & Noyes F. R. 2015)

Arthritis Tests

Certain characteristic findings can detect knee arthritis:

Crepitus

• Crepitus is the sensation when rough cartilage or exposed bone is rubbing when the knee is bent. (Lo G. H. et al., 2018)
• The examiner will feel and listen for grinding as the knee is bent back and forth.

Deformity

• As knee cartilage wears away, the knees can become progressively knock-kneed or bow-legged.

Limited Motion

• If arthritis, bone spurs, and swelling prevent normal mobility, the knee’s range of motion often becomes limited.

Torn Meniscus Tests

Tests used to determine if there is a meniscus tear include:

Joint Line Tenderness

• Joint line tenderness is a non-specific test in which the area of the meniscus is felt. It is considered a positive test when there is pain in this area.

McMurray’s test

• This test is performed with the patient lying flat. The examiner bends the knee and rotates the shin bone.
• A click can be felt over the tear as the knee is brought from full flexion to full extension. (Gupta Y., Mahara D., & Lamichhane A. 2016)

Ege’s Test

• This test is performed with the patient squatting.
• The test is performed with the leg fully externally rotated or internally rotated, depending on whether the lateral or medial meniscus is being tested.
• A click is heard or felt over the area of the tear.

ACL Tear Tests

These knee pain tests are for an anterior cruciate ligament (ACL) tear:

Lachman Test

• The Lachman test is one of the most reliable to diagnose an ACL tear.
• With the knee slightly bent, the examiner stabilizes the thigh while pulling the shin forward.
• The shin shifts too far forward with a torn ACL.

Anterior Drawer Test

• This test is performed with the patient lying flat.
• The knee is bent 90 degrees, and then the shin is pulled forward to check the stability of the ACL.

Pivot Shift Test

• The pivot shift test can be difficult, especially if the patient is experiencing discomfort and cannot relax the knee.
• This test places stress on the knee joint and assesses the rotational stability of the ACL.

Other Ligament Injuries

For a suspected injury to other ligaments, including the posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL), the following tests may be used:

Posterior Drawer Test

• The posterior drawer is performed similarly to the anterior drawer test, in which the patient lies flat.
• The knee is bent 90 degrees; the shin is pushed backward to check stability and function and detect if the posterior cruciate ligament (PCL) has been injured.

Collateral Ligament Stability

• Side-to-side stability of the knee detects problems with the MCL and LCL.
• The shin is shifted to each side, with the patient lying flat and the knee slightly bent.
• The LCL or MCL damage causes the knee to open up too much, a condition known as varus (LCL) or valgus (MCL) instability. (Ohori T. et al., 2017)

Kneecap Tests

Tests for kneecap issues include:

Patellar Grind

• In this test, also called Clarke’s sign, the patient lies on their back with the leg extended.
• The examiner pushes the kneecap down to reproduce the knee pain while the patient flexes the thigh muscles.
• Damaged cartilage can cause a grinding sensation/crepitus.

Patellar Tenderness

• The examiner can slightly lift the kneecap and place direct pressure on parts of the underside.
• The examiner looks for regions of sensitivity or pain.

Patellar Apprehension

• This test indicates an unstable kneecap.
• The examiner places pressure on the kneecap in a certain direction, and the patient may feel like the kneecap is going to pop out.

Injury Medical Chiropractic and Functional Medicine Clinic

Knee pain tests typically check the range of motion, discomfort symptoms, and sounds that could indicate a specific type of knee injury. Injury Medical Chiropractic and Functional Medicine Clinic works with primary healthcare providers and specialists to develop an optimal health and wellness solution. We focus on what works for you to relieve pain, restore function, and prevent injury. Regarding musculoskeletal pain, specialists like chiropractors, acupuncturists, and massage therapists can help mitigate the pain through spinal adjustments that help the body realign itself. They can also work with other medical professionals to integrate a treatment plan to resolve musculoskeletal issues.

Overcoming an ACL Injury

References

Frush, T. J., & Noyes, F. R. (2015). Baker’s Cyst: Diagnostic and Surgical Considerations. Sports health, 7(4), 359–365. doi.org/10.1177/1941738113520130

Lo, G. H., Strayhorn, M. T., Driban, J. B., Price, L. L., Eaton, C. B., & Mcalindon, T. E. (2018). Subjective Crepitus as a Risk Factor for Incident Symptomatic Knee Osteoarthritis: Data From the Osteoarthritis Initiative. Arthritis care & research, 70(1), 53–60. doi.org/10.1002/acr.23246

Gupta, Y., Mahara, D., & Lamichhane, A. (2016). McMurray’s Test and Joint Line Tenderness for Medial Meniscus Tear: Are They Accurate?. Ethiopian journal of health sciences, 26(6), 567–572. doi.org/10.4314/ejhs.v26i6.10

Ohori, T., Mae, T., Shino, K., Tachibana, Y., Fujie, H., Yoshikawa, H., & Nakata, K. (2017). Varus-valgus instability in the anterior cruciate ligament-deficient knee: effect of posterior tibial load. Journal of experimental orthopaedics, 4(1), 24. doi.org/10.1186/s40634-017-0087-3