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Imaging trauma of the appendicular skeleton

Leeds Teaching Hospitals, Beckett Street, Leeds LS9 7TF, UK

	Summary

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
Safe extremity reporting depends upon:

• Good quality targeted radiography.
  
• A systematic reporting technique.
  
• An understanding of injury mechanisms.
  
• Good quality clinical information.
  
• Appropriate use of imaging modalities.
  

The clinical risk management issues associated with this is only too obvious. This is exacerbated by the current shortage of doctors across all the relevant specialities, and their reduced working hours limiting their experience early in their careers. This has led to the development of Nurse and Radiographer Practitioners to address this ever increasing shortfall.

With an ever widening group of medical personnel requesting and acting upon these radiographs it is essential that all concerned are aware of the correct imaging pathways and pitfalls. This chapter does not aim to provide an exhaustive list of all appendicular injuries but will cover the potentially difficult fractures to identify and suggest when higher level imaging is appropriate.

	General trauma review

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
When reporting trauma radiographs it is essential to adopt a standard approach to avoid some of the more obvious pitfalls.

Most areas of interest should have at least two views taken preferably in an orthogonal plane. This is because a fracture is only visible if it is in the same plane as the incident X-rays ± 15° (Figure 1). Two orthogonal views are also needed because in many cases it is not only the presence of a fracture that is important, but assessment of its angular, translational and rotational displacement for guiding treatment, and this cannot be judged from a single film alone. If a fracture cannot be visualized but there remains strong clinical concern then further imaging is indicated in consultation with the referring clinicians.

View larger version (62K): [in this window] [in a new window]   Figure 1. Proximal interphalangeal dislocation. (a) The anteroposterior radiograph of the hand poorly demonstrates the grossly deformed joint due to a combination of the projection and the wrong centring point. (b) The lateral clearly shows the abnormality.

Do not accept substandard radiography. It is far easier when reporting a large number of radiographs to just accept whatever is offered up. This leads to two problems. Firstly poor quality radiographs are often completely inadequate to assess for pathology and sizeable abnormalities can be masked. This is medicolegally indefensible.

Secondly unless the radiographers receive feedback about their performance there is a tendency, particularly with the more junior staff members, to adopt less rigorous practices than are acceptable.

Once you have fully assessed the available radiographs it is essential to then correlate your findings with the clinical information given. This gives you a second bite of the cherry looking for subtle injuries, and if there is a disparity between the imaging findings and the clinical picture then it is imperative that the patient is reassessed and further imaging if appropriate is undertaken.

	Mechanisms

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
This is often overlooked but this is perhaps the most critical aspect of interpreting trauma radiographs. First you must ask yourself does the mechanism match the injury produced and if not why not? Or ask the converse, from the mechanism reported, what injuries can I expect, and do I need to look for?

• Normal fractures are caused by unusual force acting on normal bone and the force should be sufficient to break the affected bone. In these injuries the fracture margins should be clear cut with good quality bone immediately adjacent to the fracture site (Figure 2a). For example, normally to break a femoral shaft requires substantial external force such as a road crash and if this is not the case, e.g. just a simple stumble, then this is likely to represent a pathological fracture.
  
• Pathological fractures are caused by normal force acting upon abnormal bone. In these poor quality moth-eaten bone is present immediately adjacent to the fracture site. The fracture margins are poorly defined often with eroded edges (Figure 2b).
  
• Stress fractures are caused by repeated normal force acting upon normal bone. These are characterized by chronic periosteal reaction present adjacent to the fracture site (Figure 2c).
  

View larger version (83K): [in this window] [in a new window]   Figure 2. Fracture types. (a) Traumatic ankle fracture with clearly defined fracture margins. (b) Pathological fracture with the moth-eaten margins. (c) Stress fracture of the third metatarsal with chronic periosteal reaction.

View larger version (107K): [in this window] [in a new window]   Figure 3. Trimalleolar fracture of the ankle. This shows the typical Weber B pattern associated with an eversion injury with a transverse fracture medial malleolus, and an oblique fracture of the lateral malleolus and large avulsion of the posteriolateral portion of the tibia. The talus is still rotated secondary to the initial injury.

Once the mechanism has been recognised and it fits with the injury visualized the next step is to ascertain whether this is a tip of the iceberg injury. These have relatively innocuous appearances on the initial plain radiographs but they are indicative of major injuries. Examples include Segond fractures [2], extension teardrop fractures and coronoid fractures. Taking the Segond fracture to illustrate the point, the only radiographic finding is of a small flake of bone off the proximal lateral tibial immediately distal to the plateau (Figure 4). This is associated with anterior cruciate ligament injury in 75% and meniscal tears in 70%. The underlying mechanism is of external rotation and varus stress with the only bony injury being a result on avulsion of the joint capsule from the tibia.

View larger version (76K): [in this window] [in a new window]   Figure 4. Segond fracture. (a) The anteroposterior radiograph shows the small avulsion fragment of the joint capsule from the proximal tibia. (b) This a close up view of the above injury. (c) The lateral demonstrates the avulsion of the tibial anterior cruciate ligament origin.

	Classifications

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

Good classification systems should not only be prognostic but by their nature should then lead the clinician down the relevant management algorithm. For example the Schatzker Classification [3, 4] for tibial plateau fractures refers to progressively more severe injuries to the knee.

Eponyms often refer to a particular pattern of injury or alert the reader to a more significant injury than initially apparent. For example the Barton fractures are in reality fracture dislocations of the radiocarpal joint rather than simple fractures (Figure 5).

View larger version (98K): [in this window] [in a new window]   Figure 5. Volar Barton's fracture. There is an intra-articular fracture of the distal radius with the displaced volar fragment taking the carpus with it.

	Imaging

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

The key to interpreting plain radiographs is good sound clinical information as this helps to predict injury patterns and furthermore alerts the clinician to cases where other modalities are indicated.

Stress radiographs are an attempt to reproduce normal physiological stresses. The majority of plain radiographs are taken with the injured area in a relaxed position, usually after the radiographer has gone to a great deal of trouble to ensure that the area of interest is lined up in the expected anatomical position. This may well give very pretty radiographs, but where there is a pure ligamentous injury this may not be apparent. The most common areas in the appendicular skeleton where these are used are for the acromioclavicular joint and ankle ligament injuries. Unless weight bearing or stressed views are obtained these joints may look entirely normal.

Ultrasound
This is an excellent investigation for assessing ligamentous, muscle and tendinous injuries in acute trauma (Figure 6). The location of foreign bodies and joint effusions is well established. There is also some interest in the assessment of acute scaphoid injuries by high resolution ultrasound [5]. Unfortunately patients with fractures tend to tolerate ultrasound rather poorly and this limits its usefulness in this scenario. The other major limitation on ultrasound is that it is highly operator dependant and the hard copy images convey limited information. For musculoskeletal imaging it is essential that a good quality machine with a high frequency linear probe is available.

View larger version (101K): [in this window] [in a new window]   Figure 6. Muscle hernia. There is a small defect in the fascia with a small knuckle of muscle herniating through.

There are common misconceptions about the use of CT in appendicular trauma.

1. "All we are doing is recreating the plain radiograph"
   
2. "All fractures need a CT"
   

Obviously neither is true but an understanding of the reasons for this is helpful.

Plain radiographs are an excellent screening tool for fractures and in the majority of injuries they are ideal for managing the injury in its entirety. Unfortunately they only provide a composite two-dimensional image of what may be a highly complex three-dimensional structure/injury. This is particularly true where a joint is involved. CT, therefore, is an ideal diagnostic tool to provide detailed information on complex injuries (Figure 7). Until recently however its use was limited to axial data sets with relatively poor quality reformats and an inability to scan any area where metalwork had been placed.

View larger version (95K): [in this window] [in a new window]   Figure 7. Carpometacarpal fracture-dislocation. (a) There is loss of the normal carpometacarpal alignment on the plain radiograph with bony fragmentation at the trapezoid–capitate joint. CT clearly demonstrates the full extent of the injury with the splitting of the hamate (b) and diastasis of the trapezoid-capitate joint (c). Multiplanar reconstructions (not shown) confirmed dislocation of the ring and little fingers.

Taking this further the software is not limited to straight line reformats but curvilinear reformats are readily available. These can be very helpful when trying to image scoliosis patients or malunited bones for union.

The final area where this has dramatically improved is 3D imaging. This used to be considered to be purely a toy for those with too much spare time. However, although this is still partly true, it has to be remembered that surgeons operate in a 3D environment rather than the 2D data sets that we are used to. Trying to understand a complex acetabular/scapula/elbow fracture can cause premature ageing if 2D imaging only is available, however carefully prepared 3D images can often give high quality information about fracture spatial mapping. Visualizing structures in 3D can be extremely useful to a surgeon planning a surgical approach or fixation, e.g. for acetabular or tibial plateau/pilon fractures.

Nuclear medicine
In a perfect world where all resources are freely available to all patients and clinicians MRI is the modality of choice for radiologically occult injuries. However this is not the case in most UK centres and a more pragmatic approach has to be taken (Figure 8). Bone scintagrams have found widespread use in the diagnosis of impacted fractured neck of femurs and scaphoids. It is important to remember that this only becomes positive after 24 h and in the more elderly patient this can take up to 72 h. Furthermore where MRI is available the bone scintagram is a useful back-up to have for the claustrophobic patient. Another important role for nuclear medicine can be in screening for other pathological deposits after discovering one lesion or the suspicion of a pathological fracture.

View larger version (92K): [in this window] [in a new window]   Figure 8. Calcaneal stress fracture. (a) The plain radiograph demonstrates marked osteopenia. (b) The bone scintagram shows intense activity in both calacanei consistent with stress fractures.

This would undoubtedly be cost effective in terms of a huge reduction in patient morbidity as well as the inevitable improvement in diagnostic accuracy. Unfortunately the rate limiter for the use of MRI, in the UK, is availability. Many scanners are funded by national cancer initiatives and laudable though this is, it is not uncommon to find scanning time for trauma patients to be very restricted.

So having painted this very bleak picture where can we target its use most effectively.

1. Fractured neck of femurs. It is well established that 1% of these are radiographically occult at the time of presentation due to impaction. We are thus faced with a difficult diagnostic and medicolegal problem as early intervention before the fracture has had time to displace, particularly in the elderly, is the optimal care pathway. In those cases where the plain radiographs are normal but there remains strong clinical concern for a fracture then MRI is appropriate as unlike a bone scintagram this will immediately be positive even in the elderly (Figure 9).
   
2. Stress fractures. Sport and exercise are increasingly popular with the resultant overtraining particularly in the young. Stress injuries are therefore becoming much more common and early diagnosis is essential to prevent the development of full blown fractures. It is however essential to correlate these with plain radiographs as cortical changes are often poorly shown by MRI alone.
   
3. Scaphoid. There is a great deal of interest in the early diagnosis of scaphoid injuries to instigate early surgery where necessary and to prevent the overuse of cast fixation where no bony injury is present. Due to provision limitations this remains very much an investigation for the difficult and problematic cases rather than as for general screening tool for which it is ideally suited.
   

View larger version (70K): [in this window] [in a new window]   Figure 9. Impacted fractured neck of femur. (a) The anteroposterior radiograph is inconclusive due to degenerate change and marginal osteophytosis. (b) The coronal T1 weighted sequence clearly demonstrates disruption of the trabeculae in the subcapital region.

	Shoulder

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

The majority of injuries to the shoulder girdle are glenohumeral dislocations and proximal humerus fractures [6]. The proximal humeral epiphysis closes between ages 20 years and 23 years [7], the scar of the physeal plate persists and is the site of many fractures.

As with all trauma the standard examination should include two orthogonal views to ensure that a dislocation is not missed—posterior dislocation is classically missed on a single anteroposterior (AP) film (Figure 10). The patient will often be in a great deal of pain with any shoulder injury but, despite regular protestations to the contrary, it is always possible to obtain an axial view. However as a good initial screening view the scapula Y view can be substituted for the axial as an excellent way of assessing if the joint is dislocated without the problems of moving the patient's arm.

View larger version (80K): [in this window] [in a new window]   Figure 10. Posterior dislocation of the shoulder. (a) On the anteroposterior radiograph close inspection shows that the articular surfaces are no longer congruous with the "empty glenoid sign". (b) The axial view confirms the posterior position of the humeral head.

The standard approach is to assess the glenohumeral joint on both the AP and axial view which should be congruent and even. Carefully check the articular surfaces for cortical breaks as glenoid fractures can be very subtle. Measure the acromiohumeral distance (6 mm minimum) to look for rotator cuff injury and remember that a large increase in this can be secondary to a haemarthrosis.

	Elbow injuries

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
These are very much defined by the age of the patient. In children the two common injuries encountered are the supracondylar fracture of the humerus and the medial epicondyle avulsion. In the adult radial head and neck fractures are by far the most common. The reader should be alerted to the presence of a significant injury in either age group by the presence of a significant joint effusion. This is indicated by a grossly elevated anterior fat pad ("spinnaker" sign) and a visible posterior fat pad.

In the normal elbow the anterior humeral line should pass through the middle third of the capitellum as visualized on a true lateral radiograph. Misalignment of this is diagnostic for the supracondylar fracture with displacement.

It is essential to remember the order of ossification of the elbow structures to diagnose the displaced avulsed medial epicondyle. There are various mnemonics to aid in this of which the following is the only one which can be published.

C—Capitellum (2 years)

R—Radial head (5 years)

E—Medial epicondyle (5 years)

T—Trochlea (10 years)

O—Olecranon (10 years)

L—Lateral epicondyle (12 years)

The key to making this diagnosis is to be aware of the possible injury and to actively exclude this on all paediatric trauma elbow radiographs (Figure 11).

View larger version (93K): [in this window] [in a new window]   Figure 11. Avulsion of the medial epicondyle. The anteroposterior radiograph demonstrates displacement of the medial epicondyle into the joint (arrow). There is also fracture of the radial head.

Coronoid fractures are an important diagnosis to make with yet another classification system available for descriptive purposes. From the radiologist point of view these are important as this may be the only indication that there has been a dislocation of the elbow with the associated risks to the neurovascular bundle as they traverse this region. These are often difficult, if not impossible to see on the AP radiograph but almost always easily visible on the lateral. They often have a meniscal appearance and may well be substantially displaced.

	Forearm

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
Monteggia and Galeazzi fractures
The "Pizza" fractures demonstrate the classical characteristic of ring fractures [8, 9]. In both cases there is a fracture with an associated dislocation. The fracture is usually picked up but the unwary often forgets about the biomechanics and forgets to exclude the dislocation. The difficulty is remembering which is which.

Galeazzi—Ulna dislocation and radial fracture

Monteggia—Radial dislocation and ulna fracture (Figure 12)

View larger version (107K): [in this window] [in a new window]   Figure 12. Monteggia fracture dislocation. The two views clearly show both the mid shaft ulna fracture and the radial head dislocation.

	Fractures of the wrist

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
This area in particular is littered with eponyms. It is best to avoid using these as there is a good chance that although you will describe the fracture accurately you will then ascribe the wrong name.

The wrist joint is a complex unit involving the radius, ulna, triangular fibro-cartilaginous complex (TFCC), distal radioulnar joint (DRUJ) and the proximal carpal row. Fractures that extend to include the articular surface are likely to involve one or more of these structures and therefore although the imaging findings may be relatively minimal the functional outcome can be very poor unless corrected.

Intra-articular extension is a prime consideration as loss of articular surface has a serious impact upon prognosis. The chauffeur fracture is a particular variant of this in that it involves the radial styloid. It is so named as the starting handle on vintage Rolls-Royce's are very prone to kicking back and creating this classical injury. The catch with this is that it may not be visible on the standard radiographic series and if a fracture is suspected an oblique is recommended.

Extra-articular fractures are usually diagnostically straightforward. However there is the potential for involvement of the adjacent neurovascular structures. Using this logic it can be appreciated that a Smith's fracture (volar displacement of the distal fragments) is potentially far more serious, and this is compounded by the fact that this is far more unstable than a dorsally-displaced Collie's fracture [10].

Barton's fractures are classically misdiagnosed as purely intra-articular fractures when in fact these are fracture dislocations of the wrist and are highly unstable. In effect there is a fracture involving either the dorsal or radial lip of the distal radius which takes the carpus with it [11]. To avoid confusion it is best to name these as dorsal and volar Barton's, or purely as dorsal or volar fracture dislocations of the wrist (Figure 5).

Dorsal and volar intercalated segmental instability (DISI and VISI) deformities
These cause a great deal of confusion and are a rich source of A&E misses. This is probably because like lunate injuries the diagnosis is made on the lateral radiograph which often receives only a cursory inspection in the clinical setting. The key to diagnosing these is a sound understanding of the biomechanics of the proximal carpal row.

• The distal scaphoid pole naturally rotates in a volar manner.
  
• The lunate is neutral.
  
• The triquetral naturally rotates in a dorsal manner.
  
• These three bones are bound together by the scapholunate and triquetrolunate ligaments which therefore limit the degree of rotation that the triquetral and scaphoid can undergo and also maintains the neutral position of the lunate.
  

The important measurement that needs to be carried out is the relative angle of the long axis of the scaphoid and the longitudinal orientation of the lunate. This angle should be between 38° and 72°. Disruption of the scapholunate ligament releases the scaphoid to rotate in a volar manner with the lunate rotating dorsally under the influence of the triquetral. This leads to an increase in the angle. The other sign with this is the "Terry Thomas" sign due to widening of the gap between the scaphoid and lunate particularly if the hand is placed in ulnar deviation (Figure 13).

View larger version (111K): [in this window] [in a new window]   Figure 13. Scapholunate dissociation with dorsal intercalated segmental instability (DISI). (a) The anteroposterior radiograph shows widening of the scapholunate interspace (Terry Thomas sign). (b) The lateral shows dorsal tilt of the lunate relative to the scaphoid consistent with a DISI deformity.

Lunate
Injuries that involve the lunate are fortunately rare but when missed they have a poor prognosis. The key to identifying these injuries is careful inspection of the lateral radiograph. On a true lateral radiograph the middle metacarpal, the capitate, the lunate and the radius should all line up. Any disruption in this pattern raises the possibility of a dislocation. All lunate dislocations show up on the AP radiograph but this is much more difficult to interpret, usually the lunate loses its normal shape and adopts a "pie shape".

In a true lunate dislocation the lunate rotates 90° in a volar plane thus losing both its radiolunate and capitolunate articulations. As a result of this the lunate comes to lie anterior to the line of the radius and capitate.

In perilunate dislocation the lunate retains its normal relationship with the radius but the distal carpus comes to lie dorsal to the lunate. There is one final variant on this theme to be aware about and that is the midcarpal dislocation (Figure 14). In this entity the lunate partially loses its relationship with the radius and tips partially in a volar manner. The distal carpus is displaced in dorsal plane and it can be seen that this is therefore a combination of the previous two injuries.

View larger version (101K): [in this window] [in a new window]   Figure 14. Midcarpal dislocation. (a) On the anteroposterior radiograph the lunate has lost its normal shape and now looks like a pie slice. (b) On the lateral the lunate maintains its alignment with the radius but has started to tip in a volar manner.

Part of the difficulty in making this diagnosis lies with departmental protocols as these are all clearly visible on the lateral but some departments do not do these as routine. On the AP view the carpometacarpal joints should all be clearly visible in a wavy W formation across the hand. This needs to be carefully evaluated as an indistinct appearance to this is indicative of this injury. Ancillary information is loss of the normal curve of the metacarpal heads, i.e. with a dislocation shortening of the digit can be expected.

Associated fractures can be expected with these with by far the most common being a fracture of the hamate (Figure 7). This usually is disrupted at the radial margin of the little finger carpometacarpal joint and may be visible on the AP but is almost never seen on the lateral.

	Hip

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
Fractures and fracture-dislocations of the femoral head will be included in the chapter on trauma of the axial skeleton in a future edition. Fractures of the femoral neck can cause considerable problems when there is little or no displacement. A good quality lateral view is essential. Further imaging with MRI (or a bone scan) may help with diagnosis if the clinical history and images do not match (Figure 9).

Fractures of the proximal femur may be pathological, isolated fractures or avulsions of the lesser trochanter are almost always pathological.

	Knee

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
The standard views of the knee are the AP and lateral. In a trauma patient it is essential to have a horizontal beam lateral radiograph, otherwise significant effusions and lipohaemarthroses can be missed. These can be difficult to detect but the key is in the suprapatellar anatomy. There are only a limited number of structures [12] immediately superior to the patella and the suprapatella pouch only becomes visible when there is a significant joint effusion.

Review areas are the patella (fractures, dislocations and tendon ruptures), suprapatellar pouch for effusions, tibial plateau and the tibial spines.

Tibial plateau fractures
These are often underestimated by the plain radiograph; indeed often the only sign is of a lipohaemarthrosis. This used to be addressed by the use of standard tomography and obliques, however CT has now superseded these with standard sagittal and coronal reformats providing high resolution data about the fracture configuration.

Schatzker classification
The important classification to be aware of in this region is the Schatzker classification [3, 4]. The reason that this is so popular with the orthopaedic surgeons is that this has prognostic value and is also a guide towards treatment, e.g. screws alone in a Type 1, a plate and screws for a Type 3 and perhaps a ring fixator for a Type 6.

Type 1. This is a simple split involving the lateral tibial plateau

Type 2. A mixed compression and split of the lateral tibial plateau

Type 3. A pure compression of the lateral tibial plateau (Figure 15)

View larger version (116K): [in this window] [in a new window]   Figure 15. Schatzker 3 tibial plateau fracture. (a) The lateral shows a lipohaemarthrosis and the depressed tibial plateau. (b) The anteroposterior radiograph confirms the depressed lateral tibial plateau.

Type 5. The fracture extends to involve both tibial plateau often in an inverted Y configuration

Type 6. This is a Type 5 but with dissociation of the metaphysic and diaphysis

	Ankle injuries

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
Essential to the interpretation of injuries in this region is the underlying mechanism. An inversion injury classically causes lateral ligamentous injuries first starting with anterior tibiofibular ligament, then the calcaneofibular ligament and finally the posterior tibiofibular ligament. Bony injuries at the ankle would be a transverse fracture of the medial malleolus and an oblique fracture of the lateral malleolus. Conversely with an eversion injury ligamentous injuries involve the deltoid ligament and bone injuries would be an oblique fracture to the medial malleolus and a transverse fracture of the lateral malleolus (Figure 3).

Weber classification
This is the standard classification for the ankle which is based on involvement of the distal tibiofibular syndesmosis [13]. Integrity of this structure is essential for stability of the ankle joint itself. Due to the configuration a 1 mm lateral slip of the talus relative to the tibia results in a loss of 42% of the articular surface [14].

Type A. A fracture of the lateral malleolus below the level of the tibial plafond.

Type B. Fracture of the lateral malleolus at the level of the tibial plafond or immediately proximal. These may or may not involve the distal tibiofibular syndesmosis.

Type C. The fibular fracture is proximal to the distal tibiofibular syndesmosis and therefore by definition this is ruptured. There is a particular version of this where the proximal fracture is at the fibular neck with a significant risk of peroneal nerve injury (Maisonneuve fracture) (Figure 16).

View larger version (81K): [in this window] [in a new window]   Figure 16. Maisonneuve fracture. (a) The anteroposterior ankle radiograph shows widening of the medial joint space and widening of the distal tibiofibular syndesmosis. (b) The proximal fibula view confirms an oblique fracture of this bone.

	Foot

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

These are not limited purely to trauma and can be secondary to neuropathic changes or infection (Figure 17). The history, degenerate changes in the adjacent joints, erosive lesions, etc. may establish this.

View larger version (53K): [in this window] [in a new window]   Figure 17. Septic Lisfranc fracture dislocation. (a) The dorsi plantar oblique radiograph shows lysis and periosteal reaction centred around the base of the second metatarsal. (b) The lateral clearly shows the dislocation.

View larger version (61K): [in this window] [in a new window]   Figure 18. Cuboid fracture. (a) The plain radiograph shows a sclerotic line across the cuboid. (b) CT confirmed that this was a relatively undisplaced fracture.

	Summary

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 
Good quality trauma reporting depends upon:

• sound reporting technique;
  
• good quality radiography;
  
• appropriate use of imaging;
  
• good quality clinical information.
  

	References

Top Summary General trauma review Mechanisms Classifications Imaging Shoulder Elbow injuries Forearm Fractures of the wrist Hip Knee Ankle injuries Foot Summary References

 

1. IR(ME)R Ionising Radiation (Medical Exposure) Regulations 2000. Departmant of Health Document, UK.
2. Dietz GW, Wilcox DM, Montgomery JB. Segond tibial condyle fracture: lateral capsular ligament avulsion. Radiology 1986;159:467–9.[Abstract/Free Full Text]
3. Schatzker J. Fractures of the tibial plateau. In: Schatzker J, Tile M, editors. Rationale of operative fracture care. Berlin: Springer-Verlag, 1988;279–95.
4. Schatzker J, McBroom R. Tibial plateau fractures: the Toronto experience 1968–1975. Clin Orthop 1979;138:94–104.
5. Hauger O, Bonnefoy O, Moinard M, Bersani D, Diard F. Occult fractures of the waist of the scaphoid: early diagnosis by high-spatial-resolution sonography. AJR Am J Roentgenol 2002;178:1239–45.[Abstract/Free Full Text]
6. Nordquist A, Petersson CJ. Incidence and causes of shoulder girdle injuries in an urban population. J Shoulder Elbow Surg 1995;4:107–12.[Medline]
7. Hodges PC. Development of the human skeleton. AJR Am J Roentgenol 1933;30:809.
8. Bado JL. The Monteggia lesion. Clin Orthop 1967;50:71.[Medline]
9. Reckling FW, Peltier LF. Riccardo Galeazzi and Galeazzi's fracture. Surgery 1965;58:453.[Medline]
10. Dobyns JH, Linscheid RL. Fractures and dislocations of the wrist: fractures in adults (2nd edn). Philadelphia: J.B. Lippincott Co. 1984.
11. Barton NJ. Intraarticular fractures and fracture-dislocations. In: Bowers W, editor. The interphalangeal joints. New York: Churchill Livingstone, 1987;77–93.
12. Butt WP, Lederman H, Chuang S. Radiology of the suprapatellar region. Clin Radiol 1983;34:511–22.[Medline]
13. Weber BG. Die Verletzungen des oberen Sprunggelenkes. (2nd Edn.) Bern: Verlag Hans Huber, 1972.
14. Ramsey P, Hamilton W. Changes in tibiotalar area of contact caused by lateral talar shift. J Bone Joint Surg 1976;58A:356–7.
15. Aitken AP, Poulson D. Dislocations of the tarsometatarsal joint. J Bone Joint Surg Am 1963;45:246.[Abstract/Free Full Text]
16. Rogers LF. Radiology of Skeletal Trauma (3rd edn). Philadelphia, PA. Churchill Livingstone, 2002;1371–80.

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