Radiologia Brasileira - Publicação Científica Oficial do Colégio Brasileiro de Radiologia

INTRODUCTION

Imaging examinations performed for the diagnosis of fractures due to trauma are highly prevalent in radiology practice, playing an essential role because they facilitate not only the diagnosis but also the classification of the injuries. The imaging examinations usually performed in this context are conventional radiography and computed tomography (CT). The former is used as an initial imaging method, because it demonstrates bone structures well, is widely available, and is affordable, whereas the latter allows three-dimensional reconstructions, visualization of structures in other planes (providing a more satisfactory assessment of complex fractures), and better evaluation of soft tissues, such as blood vessels. The evaluation of these imaging examinations is sometimes a challenging task, especially in patients with fractures for which the management is essentially surgical, in which a delayed diagnosis can have catastrophic consequences, as is the case for the various types of fractures addressed in this study. Therefore, it is essential to recognize the main patterns of fractures and their mechanisms of trauma, as well as imaging findings that in themselves denote a greater need for surgical treatment⁽¹⁾.

This pictorial essay presents illustrative cases of the main fractures of the appendicular skeleton that require surgical management, grouped, didactically, by the joint affected. The focus is on X-ray and CT, the two methods most commonly used in emergency settings.


UPPER LIMBS

Proximal humerus fracture

Fracture of the proximal humerus is one of the most common fractures of the appendicular skeleton, accounting for 4.0–5.7% of all cases, and can occur in low- or high-energy trauma, such as falls in the elderly and motor vehicle accidents in young people. The Neer classification is used in order to assess and determine guidelines for the treatment of these fractures, classified as one to four parts: humeral head; greater tuberosity; lesser tuberosity; and diaphysis. Deviation between the parts is defined as when the distance between two parts is > 1.0 cm or the angle is > 45°^(1,2), as illustrated in Figure 1.




Terrible triad of the elbow

Characterized by posterior dislocation of the elbow together with a fracture of the coronoid process and radial head, the terrible triad of the elbow typically results from a fall onto an outstretched hand. It is usually accompanied by extensive ligament injury and, if inadequately treated, can progress to chronic instability and osteoarthritis^(1,3). Therefore, in patients with posterior dislocation of the elbow and fracture of the radial head, a CT study is recommended as a means of obtaining a more accurate diagnostic accuracy (Figure 2). Treatment of the terrible triad of the elbow is essentially surgical, the aim being to restore the congruence and stability of the joint^(1,3).




Monteggia fracture-dislocation

A Monteggia fracture-dislocation consists of a fracture of the ulnar diaphysis with dislocation of the radial head, the main mechanism of trauma being a fall onto an outstretched hand. This type of fracture-dislocation is more common in children, with a peak incidence between 4 and 10 years of age. The Bado classification subdivides Monteggia fracture-dislocations into four types, by the direction of displacement of the radial head: type I, when there is a fracture of the diaphysis of the ulna, with anterior angulation of the fracture focus and anterior dislocation of the radial head; type II, when there is a fracture of the diaphysis of the ulna, with posterior angulation of the fracture focus and posterolateral dislocation of the radial head; type III, when there is a fracture of the ulnar metaphysis with lateral or anterolateral dislocation of the radial head (Figure 3); and type IV, when there is a fracture of the proximal third of the radius and ulna, with anterior dislocation of the radial head. In the radiographic evaluation, fracture of the diaphysis of the ulna is usually easily recognized, making it necessary to investigate the dislocation of the radial head^(1,3).




Galeazzi fracture-dislocation

Often misdiagnosed, a Galeazzi fracture-dislocation, previously known as a “fracture of necessity”, is a fracture of the distal diaphysis of the radius, together with injury to the distal radioulnar joint. Galeazzi fracture-dislocations account for less than 3% of forearm fractures in children and less than 7% of those in adults, typically resulting from a fall onto an outstretched hand with the elbow flexed. Assessment of the distal radioulnar joint is essential. As illustrated in Figure 4, the signs of a Galeazzi fracture-dislocation on X-ray include the following^(1,4): fracture of the ulnar styloid process; diastasis of the distal radioulnar joint on an anteroposterior X-ray; shortening of the radius to ≥ 5.0 mm; and volar or dorsal displacement on a lateral X-ray.




Barton’s fracture

Defined as partial articular fracture of the distal radius in the sagittal plane, Barton’s fracture is more common in women and has a bimodal distribution, resulting from high-energy trauma in young people and falls in the elderly. Its management is essentially surgical. A Barton’s fracture can be categorized as volar or dorsal, depending on the direction of the deviated fragment^(1,5), as depicted in Figure 5.




Scaphoid fracture

A scaphoid fracture (Figure 6) is the most common fracture of the carpus, occurring predominantly in active men, with peak incidence in the second and third decades of life, mostly resulting from a fall onto an outstretched hand with forced extension of the wrist. Delayed diagnosis of a scaphoid fracture is a common problem, and inappropriate treatment can result in complications, including pseudarthrosis and avascular necrosis^(1,6).




The findings, classifications, and indications for the surgical management of the fractures of the upper limbs described in this essay are summarized in Table 1.




LOWER LIMBS

Pelvic ring fracture

Typically, pelvic ring fractures result from high-energy blunt trauma, such as motor vehicle accidents, and are associated with high mortality rates (up to 50% for open fractures), hemorrhage being the main cause of death. The radiological evaluation begins with the acquisition of X-rays in anteroposterior, oblique, inlet and outlet views (Figure 7). Complementation with CT is routinely performed, special attention being paid to the integrity of the pubic symphysis, sacroiliac joints, pubic branches, iliac bone, and sacrum^(1,7).




Intertrochanteric fracture

Intertrochanteric fractures are extracapsular fractures involving the greater or lesser trochanter (Figure 8).Because they are closely associated with osteoporosis, their incidence is higher in the elderly and in women. They usually occur after a fall in which there is a lateral impact on the greater trochanter. Intertrochanteric fractures are associated with high mortality, with a one-year mortality rate of up to 30%; however, surgery in conjunction with early rehabilitation reduces the associated morbidity and mortality^(1,8).




Femoral neck fracture

Femoral neck fracture is most common in the elderly and in females. Such fractures are associated with a high mortality rate, the one-year mortality rate being approximately 25%. The mechanism of trauma in femoral neck fracture depends on the age and functional status of the patient, being a low-energy lateral fall with impact on the greater trochanter in older patients and high-energy trauma in younger patients. The most widely used classification is the Garden classification, which describes four categories of femoral neck fracture: incomplete or valgus impacted (type I); complete and nondisplaced (type II); complete and partially displaced (type III); and complete and fully displaced (type IV), as shown in Figure 9. Due to the retrograde irrigation of the femoral head, two complications are feared: osteonecrosis and pseudarthrosis^(1,8).




Tibial plateau fracture

Tibial plateau fractures are joint fractures of the proximal tibia that are typically accompanied by injuries to soft tissues such as ligaments and menisci. The most common mechanism is trauma with an axial force vector, such as that caused by a fall from a great height. The classification system that has long been used is the Schatzker classification, which divides tibial plateau fractures into six types, depending on the condyle affected and the presence or absence of joint depression, shear, or both. The first three types are pure tibial plateau fractures, typically associated with low-energy trauma: shear fracture of the lateral plateau fracture without depression (type I); shear and depression of the lateral plateau (Type II); and isolated depression of the lateral plateau (Type III).The remaining three types are more severe and associated with significant soft tissue damage ^(1,9) : shear, depression, or both of the medial plateau (Type IV); bicondylar plateau fracture (Type V), as depicted in Figure 10; and complete dissociation between the metaphysis and diaphysis (Type VI).




Ankle fracture

Ankle fractures are common, occurring mainly in inversion or eversion injuries. The indications for surgical treatment include loss of joint congruence, displaced fracture of the medial malleolus, fracture of the lateral malleolus with shortening or displacement, bimalleolar fracture, and open fractures. Attention should be paid to injury of the tibiofibular syndesmosis (Figure 11), which is characterized by a reduction in the tibiofibular overlap on anteroposterior and mortise X-rays⁽¹⁾.




Lisfranc fracture-dislocation

Lisfranc ligament injury is characterized by traumatic disjunction of the medial cuneiform joint and the base of the second metatarsal. Lisfranc fracture-dislocation is a partial or complete loss of bony and ligamentous stability at the level of the tarsometatarsal joint (Figure 12). Lisfranc fracture-dislocations are uncommon, accounting for only 0.2% of all fractures. They typically affect men in the third decade of life, arising from indirect rotational forces and axial load with the forefoot flexed, in motor vehicle accidents, falls, and sports activities. Depending on the direction of metatarsal displacement, Lisfranc fracture-dislocations are subdivided into three types: ipsilateral, characterized by lateral displacement of the first to fifth metatarsals or lateral displacement of the second to fifth metatarsals, with persistence of joint congruence of the first metatarsal; divergent, characterized by lateral displacement of the second to fifth metatarsals and medial displacement of the first metatarsal; and isolated, characterized by dorsal displacement of only a few metatarsals. The main imaging finding is misalignment of the second tarsometatarsal joint, characterized by lateral displacement of the base of the second metatarsal in an anteroposterior view, with or without vertical misalignment in a lateral view^(1,10).




The findings, classifications, and indications for the surgical management of the fractures of the lower limbs described in this essay are summarized in Table 2.




CONCLUSION

Fractures are common findings in emergency radiology practice. Therefore, it is important for radiologists to be familiar with the main mechanisms of trauma and the imaging findings that inform orthopedist decisions regarding the appropriate surgical approach.


REFERENCES

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7. Khurana B, Sheehan SE, Sodickson AD, et al. Pelvic ring fractures: what the orthopedic surgeon wants to know. Radiographics. 2014;34:1317–33.

8. Sheehan SE, Shyu JY, Weaver MJ, et al. Proximal femoral fractures: what the orthopedic surgeon wants to know. Radiographics. 2015;35:1563–84.

9. Markhardt BK, Gross JM, Monu JU. Schatzker classification of tibial plateau fractures: use of CT and MR imaging improves assessment. Radiographics. 2009;29:585–97.

10. Crim J. MR imaging evaluation of subtle Lisfranc injuries: the midfoot sprain. Magn Reson Imaging Clin N Am. 2008;16:19–27.










Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM-Unifesp), São Paulo, SP, Brazil

a. https://orcid.org/0000-0003-1022-7981
b. https://orcid.org/0000-0003-4937-6634
c. https://orcid.org/0000-0002-7996-1685
d. https://orcid.org/0000-0002-9995-8723
e. https://orcid.org/0000-0003-0649-3662

Correspondence:

Dr. Lucas Kenzo Miyahara
Departamento de Diagnóstico por Imagem – EPM-Unifesp
Rua Napoleão de Barros, 800, Vila Clementino
São Paulo, SP, Brazil, 04024-002
Email: lkenzomiya@gmail.com

Received 17 February 2021
Accepted after revision 15 April 2021

Publication date: 11/01/2022