Knee Pain Overview
Types of Knee Pain
The nerves that provide sensation to the knee come from the lower back and also provide hip, leg, and ankle sensation. Pain from a deeper injury (called referred pain) can be passed along the nerve to be felt on the surface. Knee pain, therefore, can arise from the knee itself or be referred from conditions of the hip, ankle, or lower back. All of the following sources of knee pain arise from the knee joint itself.
In general, knee pain is either immediate (acute) or long-term (chronic). Acute knee pains can be caused by an acute injury or infection. Chronic knee pain is often from injuries or inflammation (such as arthritis) but can also be caused by infection.
Acute Knee Pain
Sprained and Torn Cruciate Ligaments
- Description: An anterior cruciate ligament (ACL) injury is a common sports injury generally caused by a hard stop or a violent twisting of the knee. The posterior cruciate ligament (PCL) is stronger than the ACL and much less commonly torn. The PCL requires strong forces, such as those produced when the dashboard strikes the knee in a car accident, to tear. Due to these severe forces, PCL injury is often associated with other ligamentand bone injuries.
- Symptoms: If you tear your ACL, you may hear a pop. You will also notice your knee give way or become unstable and feel pain that is bad enough that you might feel like vomiting. This will, almost always, be followed by marked knee swelling over the next couple of hours because the ACL bleeds briskly when torn.
- Treatment: Surgical repair is recommended for high-level athletes who demand optimal outcomes. Conservative treatment and knee braces may prove sufficient for those who do not demand quite so much from their knees.
- Description: Both the quadriceps and patellar tendons may rupture partially or completely. A quadriceps tendon rupture typically occurs in recreational athletes older than 40 years (this is the injury former President Clinton suffered while jogging), and a patellar tendon rupture typically occurs in younger people who have had previous tendonitis or steroid injections to the knee.
- Symptoms: Rupture of either the quadriceps or patellar tendon causes pain (especially when trying to kick or extend the knee). Those people with complete ruptures are unable to extend the knee. The patella is also often out of place either upward (with patellar tendon rupture) or downward (with quadriceps tendon rupture).
- Treatment: Tendon ruptures should be evaluated urgently. Tendon ruptures generally require surgical repair. A partial rupture may be treated with splinting alone.