Patellar tendon rupture is a tear in the patellar tendon that connects the patella, or the kneecap to the shinbone called tibia. It is a rare, yet disabling condition, mostly seen in high-level athletes under the age of 40 years.
There are two tendons attached to the patella. Above is the quadriceps (quad) tendon formed by the four quadriceps muscles. Below the kneecap, the quad tendon extends as the patellar tendon. The quad muscles, their combined tendon, and the patellar tendon all work in unison to straighten the knee.
What are the causes of Patellar tendon rupture?
The following factors can predispose to patellar tendon rupture:
Injury
Patellar tendon rupture most commonly occurs in professional athletes during sporting activities such as landing from a jump or abruptly stopping to change track when running.
The knee is usually bent and the foot planted as an athlete falls. This is because, in the bent knee position, the patellar tendon sustains more stress than the quad tendon, causing it to tear.
Inflammation of the patellar tendon
Inflammation of the patellar tendon can cause it to weaken and rupture over time. This condition most often affects professional jumpers (jumper’s knee) and runners.
Steroid Injections
Sometimes, local steroid injections near the lower portion of the kneecap used as a treatment for inflammation of the patellar tendon can also weaken and rupture the tendon.
Chronic medical conditions
Chronic diseases can also lead to inflammatory changes within the patellar tendon, damaging, weakening and finally rupturing it. Such diseases include:
- Lupus or any other condition entailing long-term steroid use
- Chronic kidney disease that requires dialysis
- Diabetes mellitus
- Rheumatoid arthritis
- Degeneration of the patella
These diseases most often tear the mid-substance (middle) of the patellar tendon, which is hard-to-fix.
What are the signs and symptoms of Patellar tendon rupture?
A person with patellar tendon rupture typically experiences:
- An audible “pop”
- Sharp knee pain, which may be felt like a shot in the back of the leg (similar to Achilles tendon rupture)
- Knee swelling
- Knee buckling or giving way
- Inability to straighten and stand on that leg
How is Patellar tendon rupture diagnosed?
After carrying out a thorough examination of the knee, your orthopedic specialist will order some imaging tests, such as an x-ray or magnetic resonance imaging (MRI) scan to confirm the tendon rupture.
In traumatic cases, patellar tendon often tears at the point where it attaches to the kneecap. A fragment of this bone will then come off along with the tendon. A “sideways” x-ray view of the knee usually reveals the displaced position of the kneecap.
The MRI helps determine the extent and site of the tear, rule out any other problem, and plan for the surgery.
What are the treatment options for Patellar tendon rupture?
Early repair or reconstruction is the key to prevent the tendon from scarring and damaging completely.
Dr. Garcia, an experienced orthopedic specialist of Seattle lists solutions for patellar tendon rupture as follows.
Drilling tunnels inside the patella: A pretty old version of repair, this method involves drilling three parallel tunnels through the patella with sutures wrapped around the patellar tendon.
Augmentation or reconstruction: Sometimes, repair with sutures alone is not enough such as in cases of a middle-tendon tear, chronic diseases, or a recent reconstruction of a ligament of the knee that uses patellar tendon as a graft.
In these cases, repairing the tendon back with newer suture anchors into the patella and then using an internal brace, augments and protects the reconstruction. Dr. Garcia relates this repair to a flat bridge-repair that doesn’t have a suspension, so the specialist puts the suspension belt on it. The rehab with this technique is relatively faster in as little as four weeks compared to the six-week period with the conventional, older technique.
PRP (Platelet-rich plasma) injections: PRP is a concentrate of a person’s own blood that is rich in blood cells called platelets, injected to stimulate healing of the injured tendon.
Using any of the above-listed options, expert surgeons like Dr. Garcia at Orthopedic Specialists of Seattle, are dedicated to providing prompt treatment and prevent disability from patellar tendon rupture.
