A tibial tubercle avulsion fracture is a complete or incomplete break 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 tibia (lower leg bone) of the powerful quadriceps thigh muscle. The growth plate is an area of relative weakness, and fracture usually occurs when sudden, vigorous activity causes the patellar tendon to pull the tibial tubercle bone away.
What Is A Tibial Tubercle Avulsion?
A tibial tubercle avulsion fracture is a complete or incomplete fracture of the growth plate at the tibial tubercle, just below the knee.
The tibial tubercle is the bony attachment of the quadriceps muscle on the tibia. In growing athletes, the growth plate is relatively weak. Sudden force from the patellar tendon can pull the tibial tubercle bone away. Whereas older adults may sustain a patellar tendon tear, growing athletes may sustain this fracture.
Causes and Risk Factors
A tibial tubercle avulsion fracture can result from sudden stressful activity, such as taking off or landing from a jump while the knee is bending and the thigh muscles are contracting. It may also occur while kicking a ball when the foot contacts the ground or an opponent.
The condition may also occur after fatigue of the tibial tubercle growth plate from overuse.
Risk factors include:
- Sports that require jumping, including basketball and high jump
- Contact sports and sports involving kicking, including soccer and football
- Being overweight
- Boys between 12 and 16 years old
- Poor physical conditioning, including strength and flexibility
- Tibial tubercle stress injury (Osgood-Schlatter Syndrome)
Symptoms
Common signs and symptoms include:
- Pain, swelling, warmth, and tenderness below the knee
- Occasionally, swelling of the knee joint
- Inability to fully straighten the leg
Treatment
Initial treatment consists of medications and ice to relieve pain and reduce 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 also be recommended for walking.
If the bones are not in the proper position, surgery is usually needed to reposition the bone and hold it with sutures, wires, or screws.
After immobilization, with or without surgery, stretching and strengthening of the injured and weakened joint and surrounding muscles are necessary. This may be done with or without the assistance of a physical therapist or athletic trainer.
The sutures, wires, or screws usually do not need to be removed unless they are bothersome.
Recovery and Outcomes
Recovery can vary between three and six months depending on the age of the patient and severity of the fracture. After surgical reduction, proper healing, and rehabilitation, a full return to sports can be expected in three to six months.
Potential complications include:
- Kneecap that is too low or too high
- Failure to heal (nonunion)
- Healing in a poor position (malunion), including knee hyperextension
- Injury to the meniscal cartilage, resulting in locking and swelling of the knee
- Arrest of normal bone growth in children
- Injury to the articular cartilage, resulting in knee arthritis
- Injury to knee ligaments, including the anterior cruciate ligament or medial collateral ligament
- Knee stiffness
- Risks of surgery, including infection, bleeding, injury to nerves resulting in numbness, weakness, or paralysis, and the need for further surgery
- Persistent prominence or bump below the kneecap
- Knee pain
When to See Dr. Chudik
Schedule an evaluation for any young athlete with a knee injury involving a pop, immediate swelling, or loss of active knee extension. Call 630-324-0402 or request an appointment online.