The patella, or kneecap, is a small bone on the front of the knee joint. Patellar subluxation occurs when the tendons that stabilize the kneecap abnormally slip out of place. This condition, which is also referred to as a partial patellar dislocation, typically occurs following traumatic injury to the knee joint. People who develop patellar subluxation symptoms should contact a doctor for further evaluation and care.
The most common symptom associated with patellar subluxation is intense pain localized to the area around the knee. Sensations of pain typically arise immediately and can worsen when a person attempts to move the affected knee, warn health experts with University of Kentucky HealthCare. Knee pain following patellar subluxation generally persists until the kneecap is put back into place. Following treatment, the affected knee joint may remain tender to the touch until the patellar tendons completely heal.
Swelling or Bruising
Patellar subluxation can cause immediate and rapid swelling of the knee joint, according to medical professionals with the University of Connecticut Health Center. The affected knee joint can appear enlarged or puffy and may be tender to the touch. Tissue damage caused by patellar subluxation can also result in skin bruising around the knee. Bruising occurs when blood pools beneath the surface of the skin and can cause the affected skin region to appear abnormally red, blue or purple in color. These patellar subluxation symptoms will progressively subside as the injury heals.
If the knee tendons slip out of place, the knee joint can feel unstable to an affected person, report University of Connecticut Health Center medical professionals. This type of injury can make it difficult for a person to place weight on the affected knee while standing or walking. Placing weight on the affected knee can cause it to give out or give way, increasing risk for affected person to lose balance or fall down. Normal knee strength typically returns to the damaged knee joint once the injury has fully healed.
In certain cases, people who experience patellar subluxation can notice that the injured knee appears deformed, reports University of Kentucky HealthCare. This occurs when the kneecap slides out of place, causing misalignment of the knee. Once the kneecap is placed back in its normal position by a doctor, knee deformity symptoms of patellar subluxation generally completely resolve.