Patella Tendon Injuries – Case of the Week
The patella tendon is a continuation of the quadriceps muscle. It spans the distance from the bottom of the knee cap (patella) to the insertion point on the tibia. The quadriceps and patella tendon work in unison as one mechanism to extend the knee.
Common Ways to Injur the Patella Tendon
Injuries to the tendon can occur from running or jumping. They can also occur from direct trauma to the knee resulting in a laceration of the tendon. Sometimes there can be gradual wear over the years to the tendon and a sudden event such as jumping from a ledge can cause the remaining tendon to completely rupture.
Symptoms of Patella Tendon Injury
When a patella tendon ruptures patients will often feel a popping sensation followed by pain and swelling. Since the tendon is no longer functioning, the patient will not be able to straighten the knee. There may be an area below the patella that shows an indentation. The patella will move up the leg since the quadriceps is still attached to the top of the kneecap.
Patella Tendon Examination
Patients should be seen as soon as possible by an orthopedic surgeon. The exam will show the disruption as the patient will be unable to voluntarily extend the knee. There will be tenderness at the site below the patella. X-rays will show the telltale sign of the patella displaced upward out of its normal position. An MRI is usually not necessary.
Treatment for Patella Tendon Injury
Almost all patients will require surgical fixation to repair the patella tendon. This is done by suturing the tendon back into the patella or the tibia depending where the tendon was torn. We often use metal corkscrew anchors with suture attached and bury these anchors into the bone. The surgery is done on an outpatient basis. The patient will be placed in a knee immobilizer with the leg fully extended. Initially, patients are allowed toe touching with crutches. This is then transitioned to full weight bearing at 4-6 weeks.
Rehabilitation After Patella Tendon Injury
Physical therapy is started early with patients doing isometric exercises at home with their knee fully extended. At 4-6 weeks patients can start formal PT and start working on bending the knee under direct supervision of a therapist.By 6 weeks the immobilizer can be discontinued. Patients are often transitioned into a brace that can adjust the range of motion. Usually complete recovery will take about 6 months, but it can take a full year to be fully functional.