Patellar Tendon Rupture
What is it? A tear of the patellar tendon that can occur either at the osteotendinous junction or midsubstance of the tendon. The disruption most commonly occurs at the attachment of the tendon on the inferior patella.
How does it present? It usually occurs with a fall onto a partially bent knee or forced contraction of the quadriceps while the knee is bent. The knee is usually quite painful and swollen. The patient often can not walk.
Common exam findings: The patient is usually unable to bear weight or walk on that leg. You will often see a large effusion and can often discern a defect below the patella (infrapatellar gap). The patella may also be quite freely mobile. With significant or full tears of the patellar tendon, the patient will not be able to do a straight leg raise.
Tests and treatment: Knee x-rays may show the patella to be higher than expected or higher than the patella on x-rays of the contralateral knee. A magnetic resonance imaging (MRI) may be needed to determine the full extent of the injury. If you suspect a patellar tendon rupture, referral to orthopedics is indicated for surgical repair.