The quadriceps tendon connects the muscles in the front of the thigh with the top of the kneecap and allows you to straighten you knee. Although anyone can tear the quadriceps tendon, these tears are more common among middle-aged people. A complete quadriceps tendon tear usually requires surgery.
Anatomy & Function
- The quadriceps muscles are a group of four that meet to form the quadriceps tendon, which connects to the top part of the kneecap (patella).
- The patella tendon attaches the kneecap to the shinbone (tibia).
- The quadriceps tendon and patella tendon work together to allow you to straighten your knee and do so with adequate power. When either of these two tendons is torn, the connection is disrupted resulting in an inability to straighten your knee.
- Mechanism of injury: Quadriceps and patella tendon tears typically occur when there is a heavy load placed on the leg with the foot planted and the knee partially bent, such as an awkward landing after a jump while playing basketball or stepping down from a high step. Tears can also result from direct trauma to the front of the knee.
- Partial tears: many tears do not completely disrupt the soft tissue. This is similar to a rope stretched so that some of the fibers are torn, but the rope is still in one piece.
- Complete tears: are exactly what they sound like, complete disruption of the tendon into two pieces. When either the quadriceps tendon or the patella tendon are completely torn, the muscle connection between the femur an tibia is disrupted and thus the knee cannot straighten when the quadriceps muscles contract.
Chronic Tendinitis: often results in abnormal quadriceps/patella tendon tissue, which is weaker than normal tissue and thus more vulnerable to acute injury. This condition is most common among people who participate in running and jumping sports.
- Chronic Diseases: Several conditions result in weakened tendons and predispose them to injury risk. Some such conditions include:
- Chronic renal failure
- Renal dialysis
- Rheumatoid arthritis
- Lupus (SLE)
- Diabetes mellitus
- Metabolic diseases
- Steroid use has been linked to increased tendon weakness
- Fluoroquinolones are a special type of antibiotic that have been linked to increased risk of tendon tears.
- A tearing or popping sensation is felt at the time of injury
- Inability or weakness with straightening the knee
- Inability to bear weight
- Change in position of the patella compared with other side (higher suggests patella tendon injury, lower suggests quadriceps tendon injury).
- Physical examination is an important diagnostic tool. Dr. Taylor will evaluate your knee for gaps in the tendon, areas of tenderness, amount of swelling, range of motion, ability to straighten the knee, and strength.
- X-ray is important to look for fractures, arthritis, and other bony abnormalities.
- MRI may be ordered to help aide in diagnosis and/or better evaluate some of the soft tissue structures.
Decisions regarding particular treatments for patellar and quadriceps tendon injuries depend on several factors such as type and size of your tear, anticipated level of activity, and age among others.
- Small, partial tears may do well with non-operative treatment that will include a period of immobilization in a brace followed by a structured physical therapy protocol.
- Complete tears of the patellar or quadriceps tendon often require, surgery to ensure functional and symptomatic recovery.
- Surgery is best performed early for these types of injury to reduce complication rates, simplify the procedure, and maximize functional recovery.
- Strict adherence to Dr. Taylor’s protocol and a structured physical therapy program is essential to a successful outcome.