Mastering Medical
USMLE Step 1 · MSK & Rheumatology

Meniscal tear vs Ligament tear

How to tell Meniscal tear and Ligament tear apart when a board question makes them look alike.

Fastest separator

Meniscus is mechanical locking/clicking with joint-line tenderness; ligament tear is instability and abnormal stress test laxity.

Side by side

Meniscal tearLigament tear
Key clue

Meniscal tear causes joint-line pain, locking, clicking, catching, delayed swelling, and positive McMurray test after twisting injury.

Ligament tear causes instability, abnormal stress testing, rapid hemarthrosis with ACL, and mechanism-specific laxity.

Mechanism

Torsional compression tears fibrocartilage, disrupting smooth knee motion.

Ligament rupture destabilizes joint translation or varus/valgus control.

Labs and tests

Joint-line tenderness, mechanical locking, and McMurray click support meniscal tear.

Lachman, drawer, valgus, or varus laxity supports ligament tear.

The trap

Both follow sports twisting injuries, so mechanical symptoms versus instability separate them.

The repair move

For knee injury, separate mechanical intra-articular catching from ligamentous instability.

Try a free question

Core

A 36-year-old man has 3 weeks of right knee pain with intermittent locking and a sensation that the knee 'catches' when he squats. Exam shows medial joint-line tenderness and a positive McMurray test (palpable click with knee flexion, external rotation, and valgus stress). There is no instability on stress testing. Which diagnosis is most likely?

Show answer and explanation

Answer: A. Medial meniscus tear. Meniscal tear presents with mechanical symptoms (locking, catching, clicking), joint-line tenderness, and positive McMurray test, without joint instability; treatment includes physical therapy, partial meniscectomy, or repair depending on tear pattern.

Why the other choices are tempting

  • B. ACL tear has joint instability with positive Lachman and anterior drawer tests.
  • C. MCL tear has medial joint-line tenderness but with valgus instability rather than mechanical locking.
  • D. Patellar tendinopathy localizes to the infrapatellar tendon, not the joint line.
  • E. Pes anserine bursitis localizes to the medial proximal tibia, not the joint line.

Flashcards

Tap a card to flip it.

What test supports meniscal tear?

McMurray test supports meniscal tear.

What symptom suggests meniscal tear?

Locking or catching suggests meniscal tear.

Quick answers

What is the fastest way to tell Meniscal tear from Ligament tear?

Meniscus is mechanical locking/clicking with joint-line tenderness; ligament tear is instability and abnormal stress test laxity.

What is the key clue for Meniscal tear?

Meniscal tear causes joint-line pain, locking, clicking, catching, delayed swelling, and positive McMurray test after twisting injury.

What is the key clue for Ligament tear?

Ligament tear causes instability, abnormal stress testing, rapid hemarthrosis with ACL, and mechanism-specific laxity.

What is the common trap with Meniscal tear vs Ligament tear?

Both follow sports twisting injuries, so mechanical symptoms versus instability separate them.