Understanding Jumper’s Knee: Insights and Treatment Strategies

By Dr. Roberto García García

Jumper’s knee, also known as patellar tendinopathy, is a common affliction among athletes, particularly in sports that involve jumping, landing, accelerating, and decelerating. This condition manifests as pain in the anterior part of the knee, specifically at the lower pole of the patella, and is often linked to repetitive mechanical stress on the knee’s extensor mechanism.

Anatomy of the Knee’s Extensor Mechanism

The knee’s extensor mechanism, crucial for extending the knee, comprises the quadriceps muscles, the quadriceps tendon, the patella, the reflex tendon, the patellar tendon, and the anterior tibial tuberosity. The quadriceps muscles stabilize the patella, while the patellar tendon connects the patella to the tibia.

Entesopathy: A Key Aspect of Jumper’s Knee

Entesopathy, or pathology at the enthesis (where tendon meets bone), plays a central role in jumper’s knee. This condition is not purely inflammatory but rather degenerative, characterized by angiofibroblastic tissue, micro-tears, and hyaline degeneration.

Etiology: The Mechanical Cause

The most widely accepted theory for the etiology of jumper’s knee is mechanical overload of the tendon. Activities like squatting and landing from a jump increase tension at the posterior deep portion of the tendon, near the knee’s center of rotation.

Clinical Presentation

Patients typically report pain in the anterior part of the knee, exacerbated by activities like sitting, squatting, or climbing stairs. Physical examination reveals pain at the lower pole of the patella, with specific maneuvers to localize and exacerbate the pain.

Diagnostic Approach

While clinical examination is usually sufficient for diagnosis, imaging studies like radiography, ultrasound, and MRI can offer additional insights, revealing changes in the tendon or enthesis.

Treatment Strategies

Treatment of jumper’s knee includes:

• Anti-inflammatory medication: Although commonly used, their effectiveness in chronic cases is questionable due to the lack of inflammatory cells in the lesion.
• Rest and cryotherapy: Rest avoids aggravating the condition, while cryotherapy provides analgesia.
• Activity modification and eccentric exercises: Eccentric training is considered the choice treatment for jumper’s knee.
• Other treatments: Extracorporeal shock wave therapy, infrapatellar straps, and local treatments like nitroglycerin patches or injections (sclerosant, corticosteroids, platelet-rich plasma, aprotinin) are other options.

Surgical Intervention

Surgery is reserved for chronic, refractory cases or partial tendon tears. Procedures may include debridement and reattachment of the tendon.

Conclusion

Jumper’s knee is a degenerative, non-inflammatory enthesopathy. Understanding its mechanical etiology and implementing appropriate treatment and rehabilitation strategies are crucial for managing this condition effectively.

This blog post, based on Dr. Roberto García García’s article, provides an in-depth understanding of jumper’s knee, its anatomical background, etiology, clinical presentation, diagnosis, and treatment options, aiding athletes and health professionals in managing this common sports injury.