What are the different types of quadriceps injuries?
The most common injury of the quadriceps is a contusion or bruise, caused by a direct blow to the anterior thigh, which can cause some blood vessels within the muscle to be damaged and bleed. This causes pain due to inflammation of the surrounding muscle. Since the rectus femoris muscle lies closest to the surface of the anterior thigh, it is the muscle most often contused.
If there is significant bleeding into the muscle, compartment syndrome may occur, where the pressure within the compartment that contains the quadriceps rises higher than blood pressure, thereby preventing muscle tissue from being supplied with oxygen-rich blood pumped from the heart.
The quadriceps may also be strained due to overuse or overstretching. The strain may involve muscle fibers, tendon fibers, or both.
Muscle strains can be categorized depending on the severity of injury. There are three different grades of muscle strains. Grade 1 strains involve muscle fibers that are stretched but not torn. Grade 2 strains involve a muscle that is partially torn with more extensive damage. Grade 3 strains occur when a muscle is completely torn.
Tendinitis describes inflammation of the tendon (itis=inflammation).
Jumper's knee or peri-patellar tendinosis describes chronic degeneration of the tendon where the muscle fibers transition into tendon fibers just above the patella (kneecap).
Quadriceps tendinitis describes inflammation of the tendon above the patella.
Patellar tendinitis describes inflammation below the patella at the level of the knee joint.
Osgood-Schlatter disease, also known as apophysitis of the tibial tubercle, occurs when there is inflammation of the bone where the patellar tendon attaches the quadriceps mechanism to the tibia. While it is most commonly seen in adolescents, it may also occur in adults.
The quadriceps or the patellar tendon may completely rupture, which leads to the inability to fully extend or straighten the knee.
Rarely, the fascia that surrounds and contains the quadriceps may tear and the muscles may herniate through the defect.