Jumper’s Knee (Patellar Tendinosis or enthesopathy): Treatment Strategies and the Advantages of Ultrasound-Guided Injections
Patellar tendinosis, commonly known as Jumper’s Knee, is a chronic overuse injury affecting the patellar tendon, which connects the kneecap to the shinbone. Unlike patellar tendinitis, which involves acute inflammation, tendinosis results from degenerative changes in the tendon due to repetitive stress without adequate healing.
What causes jumper’s knee?
Jumper’s knee is caused by overuse of your knee joint, such as frequent jumping on hard surfaces.
It’s usually a sports-related injury. It is linked to leg muscle contraction and the force of hitting the ground. This strains your tendon. With repeated stress, your tendon may become inflamed.
Symptoms of Jumper's Knee
The most common symptoms of jumper's knee include:
Discomfort and pain around the patellar tendon
Swelling in the affected area
Pain during activities such as jumping, running, or walking
Discomfort when bending or straightening the knee
Tenderness beneath the lower part of the kneecap
Risk Factors
Repetitive Jumping and Landing: Common in athletes involved in basketball, volleyball, and track events.
Muscle Imbalances: Weak quadriceps or tight hamstrings increase tendon strain.
Poor Biomechanics: Improper landing techniques and foot alignment issues.
Overuse Without Recovery: Excessive training without rest leads to microscopic tendon damage.
Types of Ultrasound-Guided Injections for Patellar Tendinosis or Tendinopathy
1. High-Volume Saline Injections (High-Volume Distention Therapy)
Involves injecting a large volume of saline (with or without local anesthetic and corticosteroids) between the patellar tendon and Hoffa’s fat pad.
Aims to disrupt neovessels (abnormal blood vessels) and nerve ingrowth, reducing pain and inflammation.
Used to improve tendon function and is commonly combined with rehabilitation exercises.
2. Platelet-Rich Plasma (PRP) Injections
PRP, derived from the patient’s own blood, contains growth factors that stimulate tendon healing.
Effective in chronic cases resistant to conservative treatments.
Often performed in multiple sessions for optimal results.
3. Corticosteroid Injections
Injected around (but not directly into) the patellar tendon to reduce inflammation.
Used cautiously, as repeated steroid injections may weaken the tendon and increase the risk of rupture.
Tendon Loading in Patellar Tendinosis Rehabilitation
A structured tendon-loading program is a key component of rehabilitation for patellar tendinosis (Jumper’s Knee), helping to stimulate tendon remodeling, restore strength, and improve function. The protocol typically follows a progressive loading approach, ensuring the tendon adapts without excessive strain.
Key Phases of Tendon Loading:
Isometric Exercises (Pain Management & Early Strengthening)
Example: Wall sits, Spanish squats, isometric leg press
Reduces pain by inhibiting nociceptive pathways while maintaining tendon load tolerance.
Isotonic (Heavy Slow Resistance) Training
Example: Eccentric leg press, slow squats, step-downs
Stimulates tendon adaptation and collagen synthesis through controlled, progressive loading.
Plyometric & Energy Storage Exercises (Return to Sport Phase)
Example: Jump squats, bounding, sprinting drills
Prepares the tendon for high-impact, explosive movements necessary for sports performance.
A gradual and individualized progression is essential to avoid tendon overload while ensuring optimal recovery. Combining tendon loading with lifestyle modifications, proper biomechanics, and recovery strategies enhances long-term outcomes and reduces re-injury risk.
Conclusion:
Patellar tendinosis (Jumper’s Knee) can significantly impact athletes and active individuals, making daily activities and sports challenging. While conservative treatments remain the first line of management, ultrasound-guided injections offer an effective option for pain relief and tendon healing in cases where symptoms persist. Additionally, lifestyle modifications, including proper nutrition, weight management, and activity adjustments, can support recovery. A structured tendon-loading rehabilitation program is essential to restore strength, function, and resilience. If knee pain continues to affect your mobility, consult a specialist to explore ultrasound-guided treatments and personalized rehabilitation strategies to aid in long-term recovery.
References:
Grönkjaer, M., Fredberg, U., Bendix, T., & Christensen, T. M. (2023). Ultrasound-guided electrocoagulation of neovascularisation for persistent patellar tendinopathy in elite athletes. BMJ Open Sport & Exercise Medicine, 10(1), e001900.
Vetrano, M., Oliva, F., Bisicchia, S., Salvatore, G., & Maffulli, N. (2021). Efficacy of platelet-rich plasma on symptom reduction in patellar tendinopathy: A systematic review and meta-analysis. Orthopaedic Journal of Sports Medicine, 9(9).
Cook, J. L., Rio, E., Purdam, C. R., & Docking, S. I. (2023). The best current research on patellar tendinopathy: A review of the literature. Sports, 12(2), 46.
D’Hooghe, P., Smith, J., Zafar, H., & Maffulli, N. (2024). A network meta-analysis of randomized controlled trials on injection therapies for patellar tendinopathy. Sports Health, 16(1), 1-10.
Bjordal, J. M., Lopes-Martins, R. A. B., & Joensen, J. (2024). Comprehensive assessment of heavy slow resistance training and ultrasound therapy in patellar tendinopathy. BMC Sports Science, Medicine and Rehabilitation, 16, 45.
Fitzpatrick, J., Bulsara, M. K., & Zheng, M. H. (2017). The effectiveness of platelet-rich plasma in the treatment of tendinopathy: A meta-analysis of randomized controlled clinical trials. The American Journal of Sports Medicine, 45(1), 226–233.
Docking, S. I., & Cook, J. L. (2016). Pathological tendons maintain sufficient aligned fibrillar structure on ultrasound tissue characterization (UTC). Scandinavian Journal of Medicine & Science in Sports, 26(6), 675–683.