Sports Medicine

Jumper's Knee

Anatomy

The kneecap (patella) connects muscles in the front of the thigh to the shinbone (tibia). As you bend or straighten a leg, the kneecap is pulled up or down. This movement of the kneecap is accommodated by a V-shaped notch (femoral groove) at one end of the thighbone (femur). The medial patella femoral ligament (MPFL)—located on the inside (medial side) of the knee—helps hold the kneecap in place and stop it from sliding/popping off of the outer side (lateral side) of the knee.

The patella tendon is in the front of the knee. It connects the patella (kneecap) to the tibia (shin bone). In growing children, the patellar tendon attaches to the growth plate of the kneecap.

Description

Jumper's knee refers to pain, ranging from mild to severe, that occurs in the lower portion of the kneecap (patella). These painful symptoms occur where the patellar tendon attaches to the patella.

Cause

Repetitive contraction of the quadriceps muscles in the thigh can stress the patellar tendon where it attaches to the kneecap, causing inflammation and tissue damage (patellar tendinitis). For a child, this repetitive stress on the tendon can irritate and injure the growth plate, resulting in a condition referred to as Sinding-Larsen-Johansson disease.

Although these types of overuse injuries in the kneecap are most common in children who are active in sports that involve jumping (such as basketball and volleyball), they can occur in children who participate in almost any sport.

Nonsurgical Treatment

Whether the problem stems from the tendon or growth plate, a child may need to rest from sports activities until the pain resolves. Your physician may also recommend applying an ice pack to the knee every 2 to 3 hours for a few days until the pain starts to go away. Nonsteroidal anti-inflammatory medications may also help to relieve painful symptoms.

A relatively recent treatment option, PRP therapy, is currently being studied by researchers and is considered by some to hold promise for certain injuries. Contact your orthopaedic surgeon to find out if PRP would be appropriate for you.

Although rare, Jumper's knee, like Osgood-Schlatter disease, can result in a fracture if the child continues to participate in sports activity without adequate rest. A fracture at the lower end of the kneecap will require treatment with casting or surgery, depending upon the type of fracture. The recovery time for a fracture of the patella requires a prolonged absence from sports.