The following symptoms and complaints may indicate knee injuries:
Leading symptoms
- Pain
- Instability
Other possible symptoms
- Joint effusion
- Joint swelling
- Deformity
Note: A rapidly bulging knee usually presents as an acute injury with hemorrhage.
Meniscus injuries
Meniscal contusion
- Local pressure pain
- No joint effusion
Meniscus tear without stretch/bend inhibition.
- Local pressure pain
- Positive meniscus signs
- Possibly joint effusion / joint swelling
Meniscus tear with stretching / bending inhibition.
- Local pressure pain
- Positive meniscus signs
- Active/passive stretch/bend inhibition.
- Possibly joint effusion/joint swelling.
Ligament injuries
Lateral ligament strain
- Localized tenderness at points of attachment/progression of the ligament.
Lateral ligament rupture
- Localized pressure pain at points of attachment/progression of the ligament.
- Instability
Anterior cruciate ligament rupture
- Anterior drawer phenomenon (side comparison).
- Positive cross-band tests
- Mostly joint effusion/joint swelling
Posterior cruciate ligament rupture
- In lateral view: tibial head displaced dorsally (knee in lateral view).
- Knee pain
- Often no joint effusion
Cartilage injuries
Cartilage contusion (cartilage bruise)
- Swelling
- Punctate pain on exertion
Cartilage damage or flake fracture (osteochondral lesions; avulsion fracture or shear fracture).
- Blocking phenomena
- Joint effusion/joint swelling
Combination injuries
Complex mediolateral joint injuries (“Unhappy Triad”).
- Severe pain
- Instability
Luxations (joint dislocations)
Knee joint dislocation
- Knee joint malalignment
- Severe instability
- Pain
Patellar luxation
- Patellar dislocation pain – pain that occurs when the kneecap (patella) is passively moved in its femoral sliding bearing under pressure.
- Deformed knee joint
- Often combined with hemarthrosis (bleeding into the joint).
- Pressure pain
Note: Snapping in the knee does not have to be from the meniscus. In one study, mechanical symptoms were equally common preoperatively in arthroscopic knee patients with and without meniscal tears.
Note: Snapping in the knee does not have to be from the meniscus. In one study, mechanical symptoms were equally common preoperatively (“before surgery”) in arthroscopic knee patients with and without meniscal tears.