A tibial tubercle avulsion fracture is a complete or incomplete break (fracture) of the growth plate of the leg just below the knee at the tibial tubercle, a prominence just below the kneecap. The tibial tubercle is the bony attachment on the large bone of the lower leg (tibia) of the big, powerful thigh muscle (quadriceps). The growth plate is an area of relative weakness, and fracture of it is usually due to sudden, vigorous activity of the patellar tendon pulling the bone away from the cartilage. Whereas older adults would sustain a patellar tendon tear, growing athletes sustain this uncommon injury. Initial treatment consists of medications and ice to relieve pain and reduce the swelling of the knee. If the bone is in the proper position or can be positioned without surgery, immobilization with a brace or cast for three to six weeks is recommended. Crutches may be recommended for walking. If the bones are not in proper position, surgery is usually needed to reposition the bone and hold them with sutures, wires, or screws.
Frequent Signs and Symptoms
- Pain, swelling, warmth, and tenderness below the knee
- Occasionally, swelling of the knee joint
- Inability to straighten the leg fully
Etiology (Causes)
This fracture results from sudden stressful activity, such as take off or landing from jumping (bending of the knee while the thigh muscles are contracting). It may also occur while kicking a ball, when the foot contacts the ground or an opponent. This force exceeds the strength of the growth plate. This condition may also occur after fatigue of the tibial tubercle growth plate with overuse.