Chiropractor Chandler AZ


The patella is a small bone that is present in front of the knee joint where the femur and shinbone meet. Its role is to protect the knee and to connect the muscles in front of the thigh to the tibia. Articular cartilage covers the end of the femur and the underside of the patella. It helps the bones to slide easily along each other during knee movements.

Tendons are strong strings of fibrous tissues that attach the muscles to the bones. The patellar tendon plays a role in leg straightening. It attaches the bottom of the patella to the top of the tibia. The patella tendons work with the front thigh muscles to extend the knee which makes kicking, running, and jumping possible. Patellar tendonitis is an injury to the patella tendons. It is also known as jumper's knee as it is the most common sports-related injury, especially in sports that involve frequent jumping like basketball and volleyball. Non-athletic people can also get patellar tendinitis. The overall prevalence of patellar tendonitis in athletes is 14% and it is twice as common among male athletes as it is among female athletes.


Patellar tendinitis is a very common injury due to overuse of the knee. It is caused by repeated stress on the patellar tendon. Stress leads to small tears in the tendon. Although the body tries to repair these tears, the continuous stress leads to more tears which causes inflammation and tendon weakness. This then leads to pain in the knee. When the tendon damage persists for more than a few weeks, this condition is called tendinopathy.


There is not a single reason of patellar tendonitis, rather it is a combination of various risk factors that leads to patellar tendonitis. These factors include:

  • Physical activity: Running and jumping are strongly associated with patellar tendonitis. Sudden increase in the intensity and duration of physical activity also puts pressure on the patellar tendons which can lead to tendonitis.
  • Tight leg muscles: Tightness in the quadriceps and hamstrings can enhance the stress on the patellar tendons.
  • Muscular imbalance: If certain muscles in the leg are stronger than other muscles, the strong muscles will pull the patellar tendons harder towards themselves which will cause stress on the tendons and can lead to patellar tendonitis.

The first symptom of patellar tendonitis is pain between the patella and tibia. This pain in the knee may:

  • At first, only present as a person starts physical activity or just after the intense physical activity is finished
  • It gets worse with time to the extent that it starts to interfere with physical activity
  • At the advanced stage, it starts to interfere with daily movements such as climbing stairs


Physical examination

Before the physical examination, the doctor will take the history of the patient to understand the cause and nature of the pain. After that, the doctor will perform physical examination in which the doctor may apply pressure to the parts of the knee to determine pain location. The pain from the patellar tendinitis is usually in the front part of the knee below the patella.

Imaging tests

The doctor can suggest one or more of the following tests diagnose the patellar tendinitis:

  • X-ray: X-ray is recommended if any other bone problem is suspected.
  • Ultrasound: Ultrasound tests use sound waves to create an image of the knee that shows if there is any tear in the patellar tendons.
  • Magnetic resonance imaging (MRI): This technique uses a magnetic field and radio waves to create detailed images that can show the small changes in the patellar tendons.

Treatment of patellar tendonitis starts with less or non-invasive techniques before considering invasive techniques such as surgery.

Lifestyle modification

Basic changes such as reducing high-intensity activities, losing weight, and resting can help to reduce pain in the knee.


Pain medications such as ibuprofen (Advil, Motrin IB) or naproxen sodium (Aleve) can be helpful in providing short-term relief from pain caused by patellar tendonitis.

Physical therapy

Different physical therapy exercises are helpful in reducing the symptoms associated with the patellar tendonitis including:

  • Stretching exercise: regular stretching exercises are helpful in reducing the muscle spasm and increasing the muscle-tendon unit.
  • Strengthening exercise: weak thigh muscles can put extra pressure on the patellar tendons. Exercises that include lowering the leg slowly after extending it are helpful to strengthen the patella tendons.
Patellar tendon strap

A strap that applies pressure on the patella tendon can be helpful in distributing the force away from the tendon and relieving the pain.


Iontophoresis is a technique that involves applying a corticosteroid drug on the skin and then applying a low electrical charge to push the drug through the skin to the knee. It is helpful for short-term pain relief.

Corticosteroid injection

An ultrasound-guided corticosteroid injection into the area around the patella tendon is helpful in pain relief. Although it gives pain relief, this relief is short-term and it can weaken the tendons if used excessively.


In some cases where the conventional treatments fail to relieve pain, surgery is recommended by doctors to repair the patella tendons. Some procedures can be done by a small cut on the knee.

Alternative treatment option

Patella tendonitis is a painful condition that can interfere with daily life activities and can even end the athletic career of the athletes suffering from it. The current treatment options available mostly work to relieve the pain so that the patient can resume normal daily activities. None of the treatment options work by repairing the tendon itself. Therefore, any treatment option that repairs the tendon will be a game changer in the treatment of patellar tendonitis.

In the past few years, a new treatment option known as Platelet-rich plasma (PRP) prolotherapy has been introduced as an effective treatment option for non-responsive patellar tendonitis. PRP prolotherapy is a part of a new branch of medicine known as Regenerative Medicine. It uses the body's own healing ability to repair the damage and relieve the pain and inflammation. The platelet-rich plasma Prolotherapy works on a very simple principle: "when the platelet concentration is increased in a certain area of the body, it accelerates the healing process." Platelets contain many chemicals known as:

  • Glycogen
  • Lysosomes
  • Alpha granules
  • Beta granules

Alpha granules contain growth factors and they are the main focus of platelet-rich plasma therapy. There are three stages of healing after platelet-rich plasma Prolotherapy injection and different types of growth factors are involved in driving different stages.

  • Inflammation phase: It lasts for 2-3 days. In this phase, growth factors are released.
  • Proliferation phase: It lasts for 2-4 weeks. It is vital for musculoskeletal regeneration.
  • Remodelling phase: It lasts over a year. In this phase, collagen is matured and strengthened and injury is healed.

20-30 mL of blood is used to make platelet-rich plasma. The blood is spun for 15 minutes at 3,200 rpm in a centrifuge machine. This step separates platelet-rich plasma from platelet-poor plasma. 3 mL of platelet-rich plasma is obtained from 20 mL of blood. The platelet-rich plasma is added to half mL of sodium bicarbonate to neutralize its pH. The injection is administered with the help of a dynamic musculoskeletal ultrasound with a transducer of 6–13 Hz to maximize the location accuracy for the injection. The injection is administered directly at the site of injury.

As the platelet-rich plasma Prolotherapy technique uses the patient's own blood, the chances of an immunogenic reaction or the transfer of blood borne diseases are completely eliminated.

The growth factors attach to the cell surface and not the nucleus of the cell, thus the chances of tumour growth are also eliminated. As the platelet-rich plasma Prolotherapy is an injection-based procedure, the risks involved in the procedure are:

  • Anaesthesia allergy
  • Infection
  • Neural trauma
  • Organ trauma
  • Needle breakage

The surgery for patellar tendonitis is found to achieve 81% satisfactory results and the average recovery time is 5-6 months. For athletes, it is a long duration that can affect their career. Therefore, PRP prolotherapy is under investigation as an alternative treatment option.

There are several research results available that show that effectiveness of PRP. The most recent research in Regenerative medicine shows that PRP prolotherapy has great anti-inflammatory properties as it inhibits Cox-1 and Cox-2 proteins in the inflammatory pathway that leads to pain reduction and increased recovery with minimum to no side effect.

A double-blind, randomised controlled trial indicated that a combination of PRP and exercise accelerates the recovery from patellar tendonitis and statistically lowers pain and increases stability and function in 12 weeks.

According to a study published in May 2015, doctors articulated concerns over the lack of standardization of PRP Prolotherapy. The research done in the past 10 years acknowledged that the role of PRP in bone, tendon, cartilage, and ligament tissue regeneration is very promising, but some controversial results have also arisen.


While PRP and stem cell treatments are enhancing the tissue repair and regeneration, conservative treatments can enhance healing, strengthen the muscles, and stabilize joint movements to maximize your recovery.


  1. Accelerated tissue repair and cell growth
  2. Photons of light from lasers penetrate into tissue and accelerate cellular growth and reproduction. Laser therapy increases the energy available to the cell so it can work faster, better, and quickly get rid of waste products. When cells of tendons, ligaments, and muscles are exposed to laser light they repair and heal faster.

    accelerated tissue repair and cell growth
  3. Faster wound healing
  4. Laser light increases collagen production by stimulating fibroblasts. Collagen is the building block of tissue repair and healing. Laser therapy increases fibroblast activity and therefore collagen production to speed healing.

  5. Reduced fibrous tissue formation
  6. Low-level laser therapy decreases scar tissue formation. Scar tissue can be a source of chronic pain and poor healing. By eliminating excessive scar tissue and encouraging proper collagen production, painful scars and chronic pain is reduced.

  7. Anti-inflammation
  8. Laser therapy causes vasodilatation (increases the size of capillaries) which increases blood flow. The treatments also increases lymphatic drainage to decrease swelling or edema. Therefore, laser therapy reduces swelling caused by bruising or inflammation while speeding the recovery process.

  9. Pain relief
  10. Cold laser therapy decreases pain by blocking pain signals to the brain. Some nerve cells sense pain and send signals to the brain. Chronic pain can be caused by overly active pain nerves. Specific wavelengths help "shut off" the pain signals, thereby eliminating your pain.

    Low-level lasers are excellent at decreasing inflammation, which also increases pain nerve activity. Cold laser therapy also increases endorphins and enkephalins, which block pain signals and decrease pain sensation. Overall laser therapy reduces painful nerve signals and reduces your perceived pain.

  11. Increased blood flow
  12. Blood carries nutrients and building blocks to the tissue, and carries waste products away. Increased blood flow to tissues increases and enhances cellular healing. Cold laser therapy increases the formation of capillaries in damaged tissue. Specific laser frequency also increases blood flow to the area treated to enhance injury repair.

  13. Increased repair and regeneration
  14. Low-level lasers increases enzyme activity to improve metabolic activity that affects cell repair and regeneration. The enzymes are turned on "high" to speed the healing.

  15. Nerve function and repair
  16. Nerves heal very slowly. Lasers speed up this process. Damage to nerves causes numbness, pain, muscle weakness, and altered sensations. Laser therapy treatments enhance nerve function, healing, and reduce pain.

  17. Increased energy production- ATP
  18. ATP is like gasoline for cells, it is the energy source that cells operate. Injured cells often have low levels of ATP, which decreases their ability to heal and repair. By increasing ATP and "gasoline storage levels," cells have the ability to heal and repair.

knee model patella labeled

Therapeutic treatments for addressing soft tissue injuries involve massage therapy, manual therapy, trigger point therapy, Graston Technique, or Active Release Technique. These treatments increase blood flow, decrease muscle spasms, enhance flexibility, speed healing, and promote proper tissue repair.

When these treatments are incorporated into a treatment plan, patients heal faster and are less likely to have long-term pain, soft tissue fibrosis, or scar tissue in the injured muscle. These soft tissue treatments are incorporated with therapeutic exercises and flexibility programs.

Many leg injuries are associated with radiating pain. The two legs function as a system for movement. Injuries in one area of the system are commonly associated with poor joint stabilization in the foot, knee, or hip. This leads to poor alignment and excessive forces being placed onto muscles and tendons. Knee injuries are common because of weakness and poor stabilization of the leg and hip muscles. The combination of muscle weakness, poor coordination, and altered gait mechanics produce excessive strain on the soft tissues.

wobble board squatting two feet

The lower extremities work as a comprehensive unit performing many of the repetitive tasks at home, work, and recreational sports. Injuries to one area of the musculature often indicate that additional damage has been incurred by other muscles.

Many therapeutic exercises can help restore proper strength and endurance to the leg muscles. Isometric exercises are often the initial treatment exercises, followed by single plane rubber band exercises for hip, knee, and ankle; flexion, extension, adduction, abduction, circumduction, inversion, and eversion. Dynamic exercises involving stability foam, rubber discs, exercise balls, and BOSU balls can be performed on the floor. The more unstable of the surface the more effort and stabilization is required of all the lower extremity muscles.

Vibration plates enhance neuromuscular learning throughout the ankle, knee, foot, hip, and back muscles. Additional strength exercises can be found on the hip, knee, and foot strengthening pages. More information for injuries and treatments foot pain and exercises.


Dragoo, J. L., Wasterlain, A. S., Braun, H. J., & Nead, K. T. (2014). Platelet-Rich Plasma as a Treatment A Double-Blind, Randomized Controlled Trial. The American Journal of Sports Medicine, doi:10.1177/0363546513518416.

Ferretti, A. (1986 ). Epidemiology of jumper's knee. Sports Medicines, 289-95.