Patellar tendinopathy (Jumper's knee).

Patellar tendinopathy, often reffered as the “jumper’s knee”, is a common knee overuse injury. Usually, affects athletes who jump frequently (volleyball, basketball), however is also very common in endurance athletes (triathletes, cyclists). The patellar tendon is the central portion of the common tendon of the quadriceps femoris, which is continued from the patella to the tibial tuberosity. As the quadriceps muscle directly controls its function and its macroscopic or microscopic appearance is similar to tendinous tissue, the term ‘patellar ligament’, should be avoided. The post will cover current concepts in regards to the causes, history, risk factors, diagnosis and treatment of the “Jumper’s knee”.
The pathogenesis of the jumper’s knee involves tendon overload. Tendon overload occurs when repetitive strain is applied to the tendon, causing microtrauma. When the microscopic destruction, via repeated strain of the tendon, exceeds the tendon’s reparative capacity, cumulative microtrauma occurs. Inadequate repair will set off a vicious circle of tenocyte death with further reduction of reparative capacity and subsequent predisposition to injury. The end result of this overload mechanism or failed healing is the formation of a tendinosis zone within the tendon and subsequent patellar tendinopathy. 
Athletes with patellar tendinopathy usually present with anteriorly located knee pain, which is exacerbated by activity or sometimes by prolonged knee flexion. The onset of pain is mostly insidious, but often patients can relate it to a period of increased (regarding frequency, intensity or duration) sport activity. The pain is well localised and most frequently located at the proximal insertion of the patellar tendon to the patella. In physical examination, the most consistent finding is localized tenderness at the inferior patellar pole.
The most important differential diagnoses for patellar tendinopathy are patellofemoral pain syndrome or Hoffa impingement.
Plain x-rays can be useful to identify associated bony abnormalities, such as in severe cases of Osgood-Schlatter or Sinding-Larsen-Johansson syndrome, or to detect the occasional intratendinous calcification. Ultrasonography and MRI have rendered the possibility of detailed visualisation of the tendon itself.
Risk factors may include too frequent and intense training, decreased quads/hams flexibility, foot hyperpronation, pes planus or cavus, forefoot varus or valgus, hindfoot varus or valgus, tibia vara, genu valgum or varum, patellofemoral malalignment, femoral neck anteversion and leg length discrepancies.
Treatment interventions may include relative rest, NSAIDs (questioned), corticosteroids (questioned), ice applications, electrotherapy, electromagnetic fields, ultrasound, laser therapy, extracorporeal shock wave therapy, stretching, eccentric exercises. When conservative treatment fails, surgical management can be opt for.
 

2 comments:

  1. Last week I increased mileage to 16 miles a week. My left knee two miles into my run started to feel tight with sharp pain on the inside toward the back and right under my knee cap. I probably shouldve of stopped and walked back but kept on. The next I could barely walk unless I wrapped it with ace wrap. tried to run on it 2 days later and about died its been 5 days now with nornal activity and is slowly healing could this be related??????

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  2. Hi Joel!
    Thanks for you comment. It could be related indeed. I would check whether it is specifically the soft tissue (patellar tendon in this case) which gives you symptoms. Also, if the tendon is tender and swollen, it could also indicate this condition. When you can not specify exact location from where the pain comes from, I would rather suggest simply the knee overload due to mileage increase. Then, I would opt for relative rest combined with ice applications followed by gradual return to running activity. Any more questions, dont hesitate to contact me. Regards

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