tibial tubercle fracturesA 15 year-old male presents to the emergency department with left knee pain and swelling after jumping while attempting to dunk a basketball. You obtain a knee x-ray (image 1 courtesy of Mark Hopkins, MD). What is your diagnosis? What patient population is at risk for this injury? What other injuries occur in this anatomical location? What is your emergency department management?

Physical examination demonstrates a swollen left knee as seen in image 2.

 tibial tubercle fractures

Image 2: Courtesy of Mark Hopkins, MD

Tibial tubercle fracture, Ogden Type IV. The Ogen classification schema is similar to  the Salter-Harris classification, but is used preferentially in the proximal tibia because of the presence of two ossification centers.

  • Primary ossification center: proximal tibial physis (Image 3, label 1). This physis ossifies posterior to anterior.
  • Secondary ossification center is the tibial tubercle apophysis (Image 3, label 2). This physis ossifies proximal to distal.

Pearl: The Ogden Classification System by type [1]:

  • I: Fracture of the secondary ossification center
  • II: Fracture propagates proximal between primary and secondary ossification center
  • IV: Fracture crosses the primary ossification center
  • V: Fracture through the entire proximal primary ossification center
  • VI: Avulsion fracture of the patellar tendon from the secondary ossification center
tibial tubercle fractures

Image 3: Normal adolescent knee, with ossification centers. Image and markings by Mark Hopkins, MD.

Tibial tuberosity fractures most commonly occur in athletes age 12-16 involved in athletics with either repetitive high force of quadriceps concentric contraction (i.e., jumping) or eccentric contraction on knee extension (i.e., landing, as in this patient). It occurs more often in males than females [1].

Pearl: In pediatric patients, the ossification center is weaker than the ligament/tendon. A physeal fracture is more common than a ligament/tendon tear. In contrast, older patients are more likely to tear tendons or ligaments in these types of injuries as they are weaker than the ossified bone [2].

Osgood-Schlatter disease, also known as tibial tubercle apophysitis. This occurs from repetitive traction stress on the secondary ossification center. The distal portion of the ossification center is the last part to close (see Image 3, label 2). Studies have been inconclusive on the relationship between Osgood-Schlatter disease and tibial tubercle fractures [1].

Patients should be placed in a knee immobilizer or long leg splint, with urgent referral to orthopedics for surgery. With proper surgical management, patients can generally expect a full recovery [1].

An important component of the knee exam is checking for an intact extensor mechanism. This helps evaluate for a quadriceps or patellar tendon rupture, aiding in management and prognosis. There are two ways to evaluate for tendon rupture:

  1. Performing a straight leg raise test while monitoring for signs of weakness or flaccidity
  2. Ultrasound (see Image 4).
tibial tubercle fractures

Image 4: Ultrasound in longitudinal view from original case, image and labels by Mark Hopkins, MD.

Check Orthobullets for more information on Tibial Tubercle Fractures and the Ogden Classification System.

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References:

  1. Frey S, Hosalkar H, Cameron DB, Heath A, David Horn B, Ganley TJ. Tibial tuberosity fractures in adolescents. J Child Orthop. 2008;2(6):469–474. PMID: 19308544
  2. Black KJL, Duffy C, Hopkins-Mann C, Ogunnaiki-Joseph D, Moro-Sutherland D. Chapter 140: Musculoskeletal Disorders in Children. In: Tintanalli, J, ed. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: Mcgraw-Hill Education. 2015:916-917
Mark Hopkins, MD

Mark Hopkins, MD

Loma Linda University Health
Mark Hopkins, MD

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William Denq, MD CAQ-SM

William Denq, MD CAQ-SM

Assistant Professor
Department of Emergency Medicine
University of Arizona
William Denq, MD CAQ-SM

@willdenq

Clinical Assistant Professor Emergency Medicine and Sports Medicine University of Arizona George Washington University '18 University of Pittsburgh '14 and '10
William Denq, MD CAQ-SM

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