Tendons In The Knee

By Alex Bigale, PTA

Tendons In The Knee

The knee is a complex joint with many components that must work together in synch to function properly.  This is why the knee is vulnerable to a multitude of injuries.  The knee is composed of bones, tendons, ligaments, muscles, cartilage, and other soft tissues.  Therefore, this article will focus on the tendons of the knee and injuries to the tendons of the knee.  Tendons are structures that connect muscles to bones, and many muscles cross the knee joint, which help maintain its structure and stability.

Tendons of the knee build stability.

Knee Tendons or Tendons in the Knee


Tendons of the Knee

The front of the thigh has four quadriceps muscles that help make the knee extend or straighten.  They are the Vastus lateralis, Rectus femoris, Vastus Medialis Oblique, and vastus intermedius.  The hamstring muscles cross the backside of the knee and help to flex or bend the knee.  These are the biceps femoris, semitendinosus, and semimembranosus. The Sartorius and gracilis muscles are two muscles that originate at the hip and attach to the tibia that perform multiple functions, but flexion is their main movement.   There are also the gastroc muscles of the lower leg that cross the knee to help move the plantarflex the foot. 

Common Injuries Involving The Tendons

The majority of tendon injuries that are related to knee pain affect the quadriceps and patellar tendons. This is mostly because the quads are responsible for directing the path of the patella (knee cap) over the trochlear groove as the knee flexes and extends. When there is an injury to a quadriceps tendon, that muscle may not engage as strongly as it should, and there becomes an imbalance of pull over the knee cap, which can cause pain and irritation.  Another common knee injury that causes pain in people who frequently run/jump or increase exercise intensity is called patellar tendonitis. This is inflammation of the tendon from repetitive or overuse.

Grading Tendon Injuries

  • Grade 1: Mild with less than 5% of fibers torn.  A person with this grade of strain has some pain but typically does not lose strength.
  • Grade 2: Moderate amount of fibers torn. Typically has more severe pain, along with mild swelling and a noticeable loss of strength.
  • Grade 3:  Full-thickness tear of the fibers.  With this injury, a person usually experiences a “pop” sensation.  This is followed by severe pain, swelling, and bruising.  Because the muscle is under tension, it is common for a full tear to result in a bunched-up muscle and a gap or dent in the skin where the muscle was.  This is a severe injury and will most likely need surgical intervention to regain function.  
ACL Ligaments

Tendons and Ligaments of the Knee

Treatment for Tendons of the Knee

For most tendon injuries (grade 1 or 2), a person can treat themselves with the RICE program.

  • Rest the injured muscle/tendon
  • Ice the injured area to reduce swelling
  • Compress the muscle/tendon with an elastic bandage
  • Elevate the injured area

Physical Therapy is needed in the healing process after a tendon injury in the knee.  The focus will be to decrease swelling and pain associated with the tear to the tendon.  The most common tendon injury in the knee is the patellar tendon.  If the patellar tendon is completely torn, it may require surgery to repair the tendon.  Smaller tears to the tendon are need immobilization to protect the tendon while it is healing.

For grade 3 tears or other injuries that do not resolve within a few days, you should contact your physician to see if other interventions are indicated for treatment.

If you want to read more about the recovery time after a patellar tendon rupture, please read this article: https://www.joionline.net/trending/content/what-recovery-time-patellar-tendon-rupture

JOI Fracture and Injury Care

JOI Physicians are currently offering ASAP Fracture care. Make an appointment by calling (904)JOI-2000. This is a new option for patients who would like to avoid the emergency room if they have suffered a fracture or soft tissue injury.  You can also make an appointment online or click below.

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By: Alex Bigale, PTA

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