IMAGING AND IMAGE- GUIDED THERAPY IN SPORTS MEDICINE

In Part I of this article we reviewed the range of modalities used in imaging of sports injuries (Box 1). We continue by discussing their application in different cases to help guide you in the methods you select for diagnosis and delivery of therapy.

BONE IMAGING Plain radiography Bones should always be evaluated initially with plain radiographs. Most fractures and joint pathology can be identified this way. A minimum of two views in perpendicular planes is obtained when investigating bone and joint injuries in order to increase pick up rates of fractures (1,2). More complex joints, such as the knee and ankle, may need additional views (2,3). Stress views or weight-bearing views are useful for providing functional information on a joint.

Fractures are seen as dark (lucent) lines running through a bone, which disrupt the bone cortices. They are classified depending on their orientation into transverse fractures, oblique fractures and spiral fractures, and they arise in different ways: n Transverse fractures: occur due to distraction forces. n Oblique fractures: occur due to a bending stress. n Spiral fractures: happen due to twisting injuries. When there are multiple discrete fragments, the fracture is termed “comminuted”. Fractures in children behave

differently due to the inherent malleability of their growing bones and the presence of growth plates (see Fig. 1). The growth plate is the weakest part of the growing bone and, in children, fractures through the growth plate can arrest growth of the bone, and this

18 PART II - APPLICATIONS

As we saw in Part I (sportEX medicine Jan 2010), there is a vast range of imaging techniques currently available that enhance your ability to diagnose and deliver treatment and rehabilitation for the athletes in your care. This second article helps you determine how appropriate each investigation is for different injuries and how each can be applied to the diagnosis and delivery of image-guided therapies.

BOX 1: MODALITIES FOR IMAGING SPORTS INJURIES

n Plain radiography n Computed tomography (CT) n Radioisotope bone scanning (bone scintigraphy) and SPECT

n Ultrasound n Magnetic resonance imaging (MRI).

can lead to significant disability. As more young athletes are participating in sport, these types of fractures are becoming more common in sports medicine. Fractures through the growth plates are common and are classified

by the Salter–Harris classification as shown in Fig. 1. The Salter-Harris system is prognostic: the higher the grade of the fracture, the greater the injury to the growth plate. This has obvious implications for management and morbidity of the patient. Another type of fracture is

the “greenstick” fracture, which is characterised by a break in a single cortex. It is typically seen in immature bone.

Type I Physis fracture

Type II Mataphysis and physis fracture

Type III Epiphysis and physis fracture

Type IV

Epiphysis to Mataphysis fracture

Type V Crush fracture

Figure 1: The Salter–Harris epiphyseal fracture classification showing growth plates (green shading) and fracture lines (black)

Computed tomography (CT) CT is an extremely powerful imaging method for assessing bone, which depends on high bony resolution, multiplanar reformatting (MPR) and three-dimensional rendering. It is useful for investigating complex fractures and dislocations in detail for preoperative planning. It has also been extensively used in the spine for obtaining information on spinal fractures and dislocations, whereby the MPR provides valuable information on the level of the lesion and can help classify and grade spinal fractures accurately (3,4).

Magnetic resonance imaging (MRI)

This is used to identify occult fractures with a high level of accuracy. The literature shows

sportEX medicine 2010;44(Apr):18-23