Tibial eminence fractures (also called tibial spine fractures) are avulsion injuries at the ACL’s attachment to the tibia, occurring primarily in skeletally immature athletes. Tibial tubercle fractures are avulsions at the patellar tendon’s insertion on the anterior tibia, typically in adolescent jumping athletes. Both are pediatric equivalents of soft-tissue injuries seen in adults and require careful treatment to preserve function.
What Are These Fractures?
Tibial eminence fractures occur when the ACL pulls off a piece of bone from the tibial spine rather than tearing in its midsubstance. This is the pediatric equivalent of an adult ACL tear, because in skeletally immature patients the bone is weaker than the ligament. The ACL itself is usually intact, attached to a displaced bone fragment that must be reduced and fixed for the knee to regain stability.
Fractures are classified by displacement:
- Type I: non-displaced
- Type II: anterior portion elevated (posterior hinge intact)
- Type III: completely displaced
- Type IV: completely displaced and rotated
Tibial tubercle fractures are avulsions at the patellar tendon’s attachment to the tibia. They typically occur in adolescent jumpers (basketball, gymnastics, track) during explosive knee extension, often during the landing phase of a jump. The fracture disrupts the extensor mechanism and produces loss of active knee extension.
Tibial tubercle fractures are classified by displacement and extension into the joint:
- Type I: avulsion of a small fragment
- Type II: displacement without extension into the joint
- Type III: fracture extending into the joint surface
- Type IV: fracture extending through the physis
- Type V: avulsion with proximal propagation into the physis
Causes and Risk Factors
Tibial eminence fractures:
- Non-contact pivoting injuries in skeletally immature athletes (age 8 to 14 most common)
- Bicycle falls with sudden hyperextension or rotation
- Sports mechanisms similar to adult ACL tears
Tibial tubercle fractures:
- Explosive jumping or landing in adolescent athletes (typical age 13 to 16)
- Basketball, gymnastics, and track and field
- Male athletes in the late growth spurt are the dominant demographic
- Underlying Osgood-Schlatter disease may increase risk
Symptoms
Tibial eminence:
- Pop at the time of injury, similar to adult ACL tear
- Immediate swelling from bleeding into the joint
- Inability to fully extend or flex the knee due to mechanical block from the displaced fragment
- Giving-way with activity
Tibial tubercle:
- Sudden pain at the front of the knee during a jump or landing
- Inability to straighten the knee or lift a straight leg
- Palpable gap or tenderness over the tibial tubercle
- Visible or palpable high-riding patella
- Swelling and hematoma over the front of the knee
Diagnosis
Dr. Chudik’s evaluation includes the mechanism and age and a physical examination focused on knee motion, extensor mechanism function, and ligamentous stability. X-rays identify both fracture types; the displaced fragment is often small but critical. MRI characterizes associated meniscus or cartilage injury and is particularly useful in tibial eminence fractures with significant swelling that limits examination. The Westmont office has on-site high-field MRI and X-ray.
Treatment
Non-surgical treatment is appropriate for non-displaced and minimally displaced tibial eminence fractures (Type I and some Type II) and for non-displaced tibial tubercle fractures with preserved active extension. It involves immobilization in extension or mild flexion for four to six weeks followed by progressive range of motion.
Surgical treatment is indicated for displaced tibial eminence fractures (Type II with mechanical block, Type III, Type IV) and for all displaced tibial tubercle fractures with extensor mechanism disruption. Dr. Chudik performs:
- Arthroscopic reduction and fixation of tibial eminence fractures using suture or screw techniques, preserving the ACL attachment to the bone fragment
- Open reduction and internal fixation of tibial tubercle fractures with screws, with repair of any associated extensor mechanism disruption
Recovery and Outcomes
Recovery after surgical fixation of tibial eminence fractures typically includes six weeks of brace protection, progressive range of motion over two to three months, strengthening over three to four months, and return to sport at four to six months.
Recovery after tibial tubercle fixation typically includes four to six weeks of brace protection in extension, progressive range of motion and weight-bearing over the following month, and return to sport at four to six months.
Outcomes are generally good with anatomic reduction and protected rehabilitation. Late complications include stiffness, residual ACL laxity in tibial eminence fractures that did not heal to full length, and physeal disturbance in tibial tubercle fractures extending into the growth plate.
When to See Dr. Chudik
Schedule urgent 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.