Radiographs Elbow

For the cervical spine C7/T1 is often visualised on the initial film however, if not, traction to the arms will improve visualisation. This needs to be applied by an experienced medical practitioner who holds the child above their elbows and gently pulls the arms towards the child s feet. Older children can be asked to stretch down to their toes to allow the cervical/thoracic junction to be demonstrated. The AP cervical spine positioning and resultant radiographs are shown in figures 2.30 and 2.31. 

Fractures in the region of the elbow can be particularly difficult to diagnose and delineate accurately. Ultrasound has been shown to be a useful adjunct to plain radiography, particularly if clinical suspicion is high and radiographs are indeterminate (Davidson et al. 1994 Markowitz et al. 1992 Vocke-Hell and Schmid 2001). With supracondylar fractures of the humerus, ultrasound may demonstrate the fracture line in association with a joint effusion and elevation of the fat pads (Figs. 4.5,4.6). 

Fig. 4.6. Lateral radiograph of the elbow confirms the diagnosis of a supracondylar fracture...

Fig. 4.5. Longitudinal image of the distal humerus in a child following trauma. There is distension of the elbow joint (arrowheads) with loss of cortical continuity (arrow) in the supracondylar region. The image has been rotated to allow comparison with the radiograph (see Fig. 4.6)...

Beltran J, Rosenberg ZS et al. (1994) Pediatric elbow fractures MRI evaluation. Skeletal Radiol 23 277-281 Bitar R, Leung G et al. (2006) MR pulse sequences what every radiologist wants to know but is afraid to ask. Radiographics 26 513-537... 

Plewes DB (1994) The AAPM/RSNA physics tutorial for residents. Contrast mechanisms in spin-echo MR imaging. Radiographics 14 1389-1404 quiz 1405-1406 Pudas T, Hurme T et al. (2005) Magnetic resonance imaging in pediatric elbow fractures. Acta Radiol 46 636-644 Rand T, Ahn JM et al. (1999) Ligaments and tendons of the ankle. Evaluation with low-field (0.2 T) MR imaging. Acta Radiol 40 303-308... 

Inclusion of the wrist and elbow in radiographs of forearm fractures is mandatory to exclude associated injuries to these joints (see Monteggia/Galeazzi). One pitfall in interpreting forearm radiographs is to misdiagnose the nutrient artery as an undisplaced fracture. This vessel maybe visualised on the AP radiograph at the junction of the proximal and middle third of the radius. It has a distal entrance point and runs obliquely in a proximal direction. 

Fig. 18.1a-g. Serial radiographs of the elbow showing the typical sequence of the appearance of the ossification centres, a No ossified centres b capitellum c radial head d internal (medial) humeral apophysis e trochlea f olecranon and g external (lateral) humeral apophysis... 

For all children having an injury to the elbow, the two standard views that should be obtained are the anteroposterior (AP) view with elbow fully extended and the forearm fully supinated (if possible). The other view is the lateral with the elbow at 90 of flexion and the forearm in neutral position. Comparison views of the other elbow should not be part of normal radiographic practice and should only be performed in exceptional circumstances, because of the radiation exposure to the child. 

When reviewing an elbow radiograph, there are important landmarks and measurements that should be reviewed to confirm the adequacy of the radiograph and to assess for any pathological changes. 

Fig. 18.4. a A lateral radiograph of the elbow, the black section represents the fat pad made visible by the distended joint capsule (hashed lines), b Joint effusion with visible dark fat pads, c Fat pads outlined... 

Clinical examination reveals a laterally swollen elbow, tender at the fracture site, which is increased by active flexion of the wrist. Interpretation of the AP and lateral radiographs depend on the degree of ossification of the capitellum and the extent of the displacement. The lesser the degree of ossification, the harder it is to assess the fidl extent of the injury. In infants, where there is no ossification of the distal humeral epiphysis, lateral condylar injury may be confused with physeal separation or dislocation of the joint Physeal separation is the conunonest of these injuries in infants less than 1 year old. Often the only sign of injury is a small sliver of displaced metaphyseal bone. 

A number of equivalent lesions have also been described. Commonest of these is the Type 1 variant Where the radial head is dislocated anteriorly but the ulna has plastic deformation rather than a fracture. Other variants include dislocations with associated radial neck fractures, olecranon fractures and dislocations of the ulnar-humeral joint. In some respects, the pulled elbow , commonly seen in infants, can also be considered a Bado I equivalent. The injury occurs when the elbow has traction applied, usually resulting in hyperextension and pronation. The radial head subluxes through the annular ligament but does not truly dislocate and radiographs are either normal or will show an effusion with elevation of the fat pads. 

Based on AP and lateral radiographs, the normal curve following around the medial condyle is disrupted. In type III injuries, it can be easy to misinterpret the radiographs as normal, since the fragment may be difficult to identify, particularly on the AP view. It is important that the acronym CRITOE is used to assess the ossification centres about the elbow joint. The medial epicondyle ossifies before that of the trochlea. If the trochlea is seen then the medial epicondyle must be present (Fig. 18.14). A displaced medial epicondyle lying within the elbow joint should not be confused with the ossification centre of the trochlea. The diagnosis should always be considered if the epicond)de cannot be visualised at an age when it should be present. 

Fig. 18.16. a Fracture of the medial epicondyle associated with dislocation of the elbow (type IV). b Image intensifier radiograph demonstrates reduction of the elbow but the epicondyle is stuck in joint rather than in an anatomical position - arrowed, c Epicondyle fixed in correct position. 

Fig. 18.18. a,b AP and lateral radiographs of radial neck fracture displaced by reduction of the dislocated elbow. Radial head lies adjacent to the capitellum. c Intraoperative radiographs showing intramedullary nancy nail and percutaneous wire used to manipulate the femoral head, d Post reduction film... 

Rogers LF, Malave S Jr, White H, Tachdjian MO (1978) Plastic bowing, torus and greenstick supracondylar fractures of the humerus radiographic clues to obscure fractures of the elbow in children. Radiology 128 145-150 Roposch A, Reis M, Molina M, Davids J, Stanley E, Wilkins K, Chambers HG (2002) Supracondylar fractures of the humerus associated with ipsilateral forearm fractures in children a report of forty-seven cases. J Pediatr Orthop 21 307-312... 

Fig. 8.74a-d. Occult fracture of the right coronoid process in a woman following a ski accident, a The patient had a negative radiographic examination performed soon after the injury, b Two weeks later, she was submitted to US examination due to persistent elbow pain and loss of extension. US identified an interruption (curved arrow) of the hyperechoic cortical profile of the coronoid process (C), just cranial to the insertion of the brachialis (br). There was associated mild intra-articular effusion. HC, humeral capitellum. c Left healthy side for comparison, d Additional oblique view of the right elbow confirms the fracture... 

Mileti J, et al. Radiographic analysis of polyethylene glenoid components using modern cementing techniques. J Shoulder Elbow Surg 2004 13(5) 492-8. 

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