Fracture Radiographs: A Rapid Review of Terminology

Authors: Brian Sumner, MD (@briansumner93, EM Resident Physician, St. Luke’s – Roosevelt); Turandot Saul, MD (EM Attending Physician, St. Luke’s – Roosevelt) // Reviewed by: Marina Boushra, MD (EM Attending Physician, Vidant Medical Center); Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit) 

Case:

A 29-year-old male without pertinent medical or social history presents to the emergency department (ED) after a fall at work. He was helping build the scaffolding for a building repair when he slipped and fell approximately 10 feet. He landed on his left foot and had immediate extreme pain in his upper left thigh. He denies hitting his head, loss of consciousness, and neck or back pain. He takes no anti-platelet agents or anti-coagulants. On arrival to the ED, his vital signs include HR 128 BP 105/74 mm Hg, RR 18, SpO2 99% on room air, and normal temperature. His examination is notable for 5/5 strength and full range of motion in his upper extremities and right leg. His left leg is externally rotated and shortened, but examination is limited secondary to pain. Pulses in the right foot are 2+ and are only detectable by Doppler on the left. Capillary refill is delayed in the left foot.  His neurological, cardiovascular, respiratory, and abdominal exams are non-contributory. An x-ray reveals the following:

Introduction: 

According to the National Center for Health Statistics, there are over 42 million annual injury-related ED visits and 3.8 million visits for traumatic fractures.[1] With the increasing dependence on off-site orthopedic providers with no real-time access to radiologic images, emergency medicine (EM) provider proficiency in communication of injury characteristics is critical for the management of these patients. These skills are even more important in cases of mass casualty events, electronic system failure, rural job placement, lack of radiologist support, as well as other scenarios where verbal communication predominates. The following is a basic step-by-step approach to isolate the critical components of an orthopedic fracture. 

 

1. Open or Closed:  

Evaluate for communication of the fracture with the external environment.[2]  If such communication exists, it is classified as an open fracture. Any open wound near the site of fracture should be considered open. Open injuries can be further subdivided based on the Gustilo-Anderson Classification (Table 1). When caring for an open fracture, it is important to consider the magnitude of actual and potential soft tissue damage. Broken bone fragments have potential to tear soft tissues, including arteries and other vital structures – as such, appropriate immobilization is prudent.[3] Open fractures also require appropriate antibiotic coverage (See Table 1).[3] Clostridium tetani has a propensity to grow in unhealthy tissues. Therefore, tetanus prophylaxis should be considered in every patient with an open fractures.[3]  Copious irrigation with sterile isotonic saline is recommended.[3] Lastly, there is no unified consensus on how rapidly an open fracture should be debrided and operatively irrigated, however, the general consensus is within 6 hours. One recent study did note that delay past 8 hours for operative management of lower extremity open fractures resulted in an increased risk of infection; the same was not seen for upper extremity wounds.[4] 

2. Fracture Location

The classification of fracture location will depend largely on the bone involved. For long bones, which are bones that are longer than they are wide, the general anatomic divisions are the epiphysis, metaphysis and diaphysis. Mid-shaft, proximal and middle third junction, or distal and middle third junction are other ways of communicating the location.[5] Other bones, such as those of the face and vertebral column, do not use the same terminology. Additionally, fractures are described regarding joint-space involvement. When a fracture involves the joint place, it is deemed to be intra-articular. Intra-articular fractures are more commonly associated with long-term complications including but not limited to osteoarthritis.[6] Extra-articular fractures are those which do not involve the joint plane (such as a transverse midshaft humeral fracture). 

Long bone fractures in the pediatric population have specialized terminology. In children, the growth plate, or physis, is the location of development of new bone and sits between the metaphysis and epiphysis. In some long bones, such as the phalanges, the growth plate is only present at one end, while in other long bones, growth occurs at both ends.[7] The development of cartilaginous matrix that will later be ossified is pivotal to vertical and linear growth of long bones. Salter-Harris fractures are fractures in long bones which involve the physis. The more severe the type of fracture, the higher the likelihood of disruption in linear growth. 

Salter-Harris Types[7] 

  • Salter-Harris Type I: Widening of the physis 
    • Very low incidence of growth disturbance 
  • Salter-Harris Type II (most common 75%): Fracture line involves some portion of the physis and travels out through metaphyseal bone 
    • Low Incidence of growth disturbance – physis cells stay in position despite fracture involvement 
  • Salter-Harris Type III:  Intraarticular fracture from the epiphysis into and through the physis to the periphery of the bone 
    • Prognosis varies depending on level of microvascular compromise to the physis cells 
  • Salter-Harris Type IV: Intraarticular fracture from the epiphysis, through the physis, extending out through the metaphysis 
    • High likelihood of growth disturbance without precise reduction 
  • Salter-Harris Type V: Crushing injury of the physis destroying the reproductive proliferative cells 
    • Often associated with significant disruption to long bone growth 

3. Fracture morphology [8] 

There are several fracture types, demonstrated in Table 2.  

Briefly, one term commonly used to describe a greenstick fracture is an incomplete fracture because the bone bends but does not fracture through its cortex on either the concave or convex side. Other fractures which include disruption of the cortex are called complete fractures. 

 

 4. Displacement

 Displacement can be measured by how far the position of the bone deviates from normal alignment. This can be measured and presented in two ways: 

  • Measurement of the space between the bone fragments that would normally be in-line. Example: the tibial fracture is displaced 4 mm.[5] 
  • Measurement of the entire bone width, then discussing the measurement of the space between the bone fragments as a percentage of total bone width. Example: There is 50% displacement of the tibia.[5] 

Commonly, providers will discuss displacement as minimal, moderate or severe. Unfortunately, there is no established threshold for how much displacement is required to fit into each category. Quantitative measures should be used when possible as they allow for an improved description of fracture findings and can be objectively compared over time. 

 

5. Shortening 

When the continuity of the bone is disrupted by a fracture, the fracture segments are pulled towards one another by the intact musclesmost commonly with proximal migration of the distal bone fragment. The resulting overlap leads to a shortening of the total bone length. This should not be confused with IMPACTION, which can be seen with torus/buckle fractures when bone collapses in on itself without compromising the lateral margins of the bone itself. 

 

6. Angulation

Angulation refers to the angle the distal fragment forms with the proximal fragment.[4] Components of this include direction of angulation and number of degrees. The degree of angulation can be measured by drawing a line through the long axis of a broken bone from both the intact region and fractured segment. The direction can then be communicated as the way in which the apex of this angle points (valgus/lateral, varus/medial, anterior, posterior).[5, 8] 

 

7. Rotation 

Upon fracturing, bone fragments may rotate on themselves. This is often difficult to see on an x-ray film as they are only in two dimensions. Physical exam is often the first clinical indicator rotation has occurred. Consider a proximal femur fracture – the patients affected leg will likely be visibly externally rotated. Identifying rotation is important as improper reduction of a rotated fracture may lead to increased morbidity.  

Back to our patient…

The fracture can be described as a closed, midshaft diaphyseal femur fracture with an oblique and descending longitudinal fracture line with minimal displacement, shortening, and 10-15 degrees of lateral angulation.

 

Pearls:

  • Describe if open or closed.
  • Describe the fracture location along the bone.
  • Describe the fracture morphology.
  • Describe any displacement.
  • Describe any shortening.
  • Describe any angulation and rotation.

 

References/Further Reading:

  1. Nawar, E.W., R.W. Niska, and J. Xu, National hospital ambulatory medical care survey: 2005 emergency department summary. 2007.
  2. Reid, M. and W. Stehr, The Mont Reid Surgical Handbook. 2008: Saunders/Elsevier.
  3. Okike, K. and T. Bhattacharyya, Trends in the management of open fractures: a critical analysis. JBJS, 2006. 88(12): p. 2739-2748.
  4. Malhotra, A.K., et al., Open extremity fractures: impact of delay in operative debridement and irrigation. Journal of Trauma and Acute Care Surgery, 2014. 76(5): p. 1201-1207.
  5. Menkes, J.S., Initial evaluation and management of orthopedic injuries. Tintinalli J, Kelen G, Stapczynski J. Emergency Medicine: A Comprehensive Study Guide, 2003. 6.
  6. McKinley, T.O., et al., Basic science of intraarticular fractures and posttraumatic osteoarthritis. Journal of orthopaedic trauma, 2010. 24(9): p. 567.
  7. Boutis, K., Pediatric Orthopedic Emergencies, in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e, J.E. Tintinalli, et al., Editors. 2020, McGraw-Hill Education: New York, NY.
  8. Amini, B. and Z.A. Metwalli, Musculoskeletal, in Introduction to Diagnostic Radiology, K.M. Elsayes and S.A.A. Oldham, Editors. 2015, McGraw-Hill Education: New York, NY.

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