The patellar tendon connects the patella (kneecap) to the anterior tibia. The tendon helps the muscles of the quadriceps extend the knee joint. Injury to this tendon is common in athletes who frequently jump as part of their sports activity such as basketball or volleyball. Injury to this tendon is commonly called “jumper’s knee.” More than 200,000 cases are reported yearly in the United States.
The term “jumper’s knee” was first used in 1973 to describe an insertional tendinopathy. That’s a tendon injury usually seen in athletes with pain at the site where the tendon attaches to the tibia. Jumper’s knee is caused by a frequent recurrent stress which overloads the insertion site.
Patellar tendonitis is one of the most common tendinopathies affecting mature athletes. It occurs in approximately 20% of athletes who jump as part of their sport.
Bilateral patellar tendinopathy occurs in both males and females equally.
Unilateral tendinopathy occurs in twice as many males than females.
Although typically seen in jumping sports such as basketball, volleyball this condition can also be seen in weightlifting and cycling.
Risk Factors
- Greater body weight
- Valgus or varus knee angle
- Limb length inequality
- High kneecap or low kneecap position
- Poor hamstring and quadricep flexibility
- Overtraining
- Sports played on hard surfaces
The patellar tendon experiences greater mechanical load stresses during landing because of the off- center contraction of the quads rather than the symmetrical contraction during jumping. It is the mechanical and off -center tension which causes the injury. The true cause of jumper’s knee remains unclear because biopsy of the tissue does not show inflammation which would be present in a classic tendonitis. Therefore, it is considered a tendinosis which is a tendon injury without inflammation.
Classification
Depending on the duration of the symptoms, patellar tendonitis is classified into 4 stages:
- Pain only after activity with no function impairment
- Pain during and after activity although the patient can still participate in the sport
- Pain during and after activity with difficulty participating in the sport
- Complete tendon tear requiring surgery
Diagnosis
- History and physical exam remain the primary means of diagnosis
- X-ray analysis is rarely used but could be useful if other pathologies are being considered
- Ultrasound and MRI are highly sensitive for detecting tendon abnormalities
Treatment
Stage One is characterized by pain only after activity and no functional impairment:
- Rest and activity modification- decrease activities that increase kneecap and upper leg pressure such as squatting and jumping
- Cryotherapy- ice application 4-6 times daily for 30- minute intervals
- Stretching- all muscle groups involved;
Flexors of the hip and knee (hamstrings, gastrocnemius, iliopsoas, rectus femoris, adductors.)
Iliotibial band- a large tendon like structure on the outside of the hip and upper leg
Extensors of the hip and knee- quadriceps, gluteals
- Physical therapy to help strengthen muscle groups
- Ultrasound or phonophoresis to deliver medicine into the tissues
- Bracing
- Massage therapy
- Medicines such as anti-inflammatory (NSAIDS, Motrin, Voltaren) oral or topically
- Extracorporeal shock wave therapy
Stage Two is characterized by pain both during activity and after but still able to participate
- All of the above- should be treated aggressively until the pain decreases
- Steroid injection (this will be discussed later in this text)
Stage Three which is characterized by sustained pain and the athletic performance is adversely affected
- All of the above
- Sports participation ceases
- Relative rest from sports activities for 4-6 weeks
- If the condition does not improve, surgery may be considered
Stage Four which is complete tendon rupture requires surgical intervention.
Discussion
Knee immobilization is not recommended as it can result in more stiffness and further joint problems. This can lead to further prolonging the athlete from returning to full activities.
NSAIDs such as Motrin, Naprosyn, Voltaren should only be used for a total of 14 days as chronic use may cause significant other problems.
Corticosteroid Injections are accomplished by ultrasound and the injection is given around the sheath. This may relieve the pain. However, as mentioned earlier, there may be little or no inflammation present in this condition. (tendinosis) Also, these types of drugs can also weaken the tissue and tendon and make them more likely to rupture. The use of corticosteroids should be discouraged and avoided.
Platelet Rich Plasma is and autologous biologic concentrate from one’s own blood. These injections have been proven to promote new tissue formation and repair the tendon damage.
Studies
Knee Surg Sports Traumatol Arthrosc 2018 Jul;26(7): 1984-1999 PMID 27665095
Purpose: Platelet Rich Plasma is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present stud was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.
Results: The research identified the clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendons…
Conclusion: Patellar tendons seem to benefit from PRP injections
Curr Rev Musculoskelet Med 2018 Dec;11(4): 624-634. PMID 30353479
Purpose: This review evaluates the current clinical literature on the use of platelet rich plasma in order to develop evidence- based recommendations for various musculoskeletal indications
Conclusion: PRP appears to be a viable treatment option for chronic refractory patellar tendinopathy
J Orthop 2020 Mar-Apr: 18: 91-94 PMID 32189891
Purpose: Patellar and hamstring tendinopathy are common injuries among elite athletes. Platelet Rich Plasma has emerged as a promising new therapy for accelerating healing and shortening recovery in patients with these conditions. We present 15 cases of PRP injection used for either patellar or hamstring tendinopathy in varsity collegiate athletes.
Results: Studies assessing the impact of patellar tendinopathy on athletes have found it to be extremely debilitating injury. In our small case series, all but one of the varsity athletes who underwent PRP treatment for chronic patellar tendinopathy were fully cleared to return to sport within four months and all athletes who received treatment were able to return to full sport by 10 months
Conclusion: Both patellar tendinopathies and hamstring injuries are extremely common , often recurrent injuries among elite athletes that can often result in lengthy recovery times. This case series supports the use of PRP in promoting return to sport in varsity athletes
Clin J Sport Med 2014 Jan;24(1): 88-9. PMID 24366015
Objective: To compare the effectiveness of injections of platelet rich plasma compared with focused extracorporeal shock wave therapy (ESWT) among athletes with chronic patellar tendinopathy
Conclusion: Athletes with chronic patellar tendinopathy responded positively to both PRP injection and ESWT. However, the PRP treated patients demonstrated significantly higher improvements in VISA-P and pain scores by 6 months and significantly better functional outcomes and satisfaction at 12 months
Juventix Regenerative Medical is an industry leader in the regenerative medical field. Our Platelet Rich Plasma Kits are FDA approved and designed for safety and effectiveness. They are cost effective and very easy to use. Our kits provide consistency of concentrated product when obtained from the same source.
Juventix Regenerative Medical offers a patent pending LED Photo- Activator to activate the platelets and begin the regenerative process. The activation, a critical step in the release of cytokines and growth factors, is accomplished with light and not with the addition of other chemicals such as Calcium Chloride or Thrombin.
Juventix Regenerative Medical supplies a Bio-Incubator that transforms the Platelet Rich Plasma into an Injectable Platelet Rich Fibrin. The PRF, commonly called the “second generation of platelet products, has a broader range of clinical applications while providing outstanding outcomes.
RESTORE, REVIVE, REGENERATE- JUVENTIX REGENERATIVE MEDICAL
Regenerative Regards,
Dr. Robert McGrath
