44 David Sutton

DAVID SUTTON PICTURES

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig. 44.1 Extradural haematoma: CT scan. A well-defined area of increased density is seen. The clear-cut convex inner margin is diagnostic of an extradural collection.

• Fig. 44.2 Depressed skull fracture. (A) A curvilinear density overlies the posterior parietal region on the lateral view. (B) On the Townes' view, the depressed nature of the defect can be appreciated (arrows).

• Fig. 44.3 Skull fracture: CT scan demonstrates a large extradural

• haematoma with, in addition, obvious high-density blood in the right

• frontal lobe. Low-density air 'bubbles' are also seen, indicative of fracture

• communicating to the outside environment, most likely via the frontal

• sinuses.

• Fig. 44.4 MRI of right temporal lobe contusion (T,-weighted). There is irregular high signal intensity within the temporal lobe, following trauma to the tempoparietal region of the skull.

• Fig. 44.5 Facial fracture lines. The lines of the common fractures are marked on the skull: 1 = low transverse fracture; 2 = pyramidal fracture; 3 = high transverse fracture. The numbers also relate to the Le Fort lines of weakness

• Fig. 44.6: CT of facial fracture. (A) Fractures are identified through the anterior and lateral walls of the right maxillary sinus (arrows), and pterygoid plate (open arrow). There is complete opacification of the right antrum and nasal passage from haematoma, and a fluid level in the left antrum due to a maxillary fracture (not seen on this image). On another cut (B) the zygomatic arch fracture is also seen (arrow), and there is obvious depression of the zygoma. The left maxillary fracture is also seen (open arrow).

• Fig. 44.7 Zygomatic inferior orbital rim fracture: 3D CT. The zygomatic arch and inferior orbital rim are depressed on the right, with a comminuted fracture involving the inferior orbital rim (large arrowhead) and frontozygomatic suture (small arrowhead).

• Fig. 44.8 (A) CT scan demonstrates an air-fluid level in the left maxillary antrum, and a fracture of the anterior wall (arrowhead). (B) 3D reconstruction of the face, showing the fracture.

• Fig. 44.9 Mandibular fracture (arrow): 3D CT. Fine detail is provided by the 3D reconstruction.

• Fig. 44.10 Fractures of the mandible following direct injury. As with other bony rings, fractures in two places ar common. Fractures involve the right canine region and the neck of the left condyle.

• Fig. 44.11 3D CT of the spine. Note crush fracture of the body of LI, with anterior subluxation of T12 on LT.

• Fig. 44.12 MRI of the cervical spine: T2 -weighted image. There has been a fracture of C6, with mild posterior displacement of the dorsal fragment of the vertebral body (curved arrow). A focal area of high signal within the spinal cord at this level (straight arrow) indicates a focal cord injury.

• Fig. 44.13 MRI: spinal cord contusion. This gradient-echo sequence shows a focal area of decreased signal in the cord posterior to the hyperplexion teardrop fracture of C5 (arrowhead), compatible with intracellular deoxyhaemoglobin. There is surrounding high signal oedema.

• Fig. 44.14 Normal cervical spine. Five lines should be drawn in the mind. A and P are the anterior and posterior longitudinal lines respectively. These run along the margin of the anterior and posterior longitudinal ligament. L is the spinolaminar line, which runs between the anterior margin of the dorsal spines, outlining the posterior margin of the spinal canal. The asterisks represent the spinous line, along the posterior margin of the dorsal spines. F is the posterior pillar line, along the posterior margins of the articular pillars. Note divergence of the posterior pillar line in the upper and mid spine, due to mild positional rotation.

• Fig. 44.15 Unilateral facet dislocation. There is an abrupt change in the laminar space (between the spinolaminar line and the posterior articular pillar line) at the C3-C4 level, indicating rotation. There is also a mild anterior subluxation of C3 on C4.

• Fig. 44.16 Unilateral facetfracture-dislocation. There is a

mild anterior subluxation of C5 on C6; also there is overlap of the posterior articular pillar lines at C6, but separation at C5, indicating rotation. The superior facet of C6 has been fractured, and rotated forwards with the anteriorly displaced inferior facet of C5 (arrow).

Fig. 44.17 Hyperflexion sprain/wedge compression fracture. There is a wedge compression fracture of C6 with marked widening of the interspinous distances of C5-6; also, widening of the facet joint at C5-6, with near ' perching' of the inferior facets of C5 on the superior facets of C6.

• Fig. 44.18 Hyperflexion sprain. Note widening of the interspinous distance at C5/6, with additional widening of the facet joints, and superior subluxation of the facets of C4 on C5 and posterior intervertebral joint. This picture indicates severe ligamentous disruption.

• Fig. 44.19 Bilateral locked facet. C2 has leap-frogged over C3, and now lies with its inferior facets anterior to the superior articular facets of C3.

• Fig. 44.20 Flexion teardrop fracture of C5. Note anterior compression of C5, with a fracture of the anterior inferior aspect. A very small avulsion is also seen at the anterior, inferior aspect of C4.

• Fig. 44.21 Hyperextension fracture of the articular pillar of C3. (A) There is obvious bone disruption of the posterior elements of C3, involving both the articular pillars, (closed arrow) and lamina (open arrow). (B) Tomography demonstrates the crush fracture of the articular pillar, with posterior displacement of the posteroinferior fragment (arrow).

• Fig. 44.22 Hangman's fracture. Classical oblique fractures through the pars interarticularis of C2 are associated with anterior subluxation of the body of C2.

• Fig. 44.23 Low Hangman's fracture. Note the similarity to the Hangman's fracture pattern, but at a lower level. (A) There is anterior subluxation of C5 on C6, with an oblique fracture through the posterior arch of C5, indicating the anterior/inferior direction of the force vector, from the posterior elements of C5, caused by massive hyperextension. This is a fracture pattern typical of the hangman's fracture at C2. (B) Diagrammatic representation of the 'low hangman's' fracture. The extension force has a rotary configuration (small arrow heads), with an inferior/anterior component to the vector (large arrow), as in the true hangman's fracture.

• Fig. 44.24 Jefferson burst fracture of C1. (A) The lateral view indicates anterior displacement of the anterior arch of C1 with respect to the odontoid process (open arrow). There is marked prevertebral soft-tissue swelling (closed arrows). (B) The AP view demonstrates lateral displacement of the lateral masses of C2. (C) Axial CT of Jefferson fracture of atlas. Contrast in subarachnoid space outlines cord.

• Fig. 44.25 Low (Type II) odontoid fracture. The fracture passes through the base of the odontoid process with slight separation, and anterior displacement of the odontoid process and ring of C1.

• Fig. 44.26 Low (Type III ) odontoid fracture. (A) The lateral radiograph demonstrates interruption of the radiographic 'ring‘ of the body of C2 (arrows). (B) CT demonstrates the nature of the fracture, through the body of C2

• Fig. 44.27 Os odontoideum. The tip of the odontoid process is separated from the body, with smooth, well-corticated margins (arrows).

• Fig. 44.28 Mach effect. An apparent fracture through the base of the odontoid process is due to the overlying posterior ring of C1 (arrows).

• Fig. 44.29 Rotatory subluxation of C1 on C2. Despite a nearly perfect AP view (A), there is asymmetry of the C1 /C2 articulation with narrowing of the left (arrow), which cannot be attributed to patient positioning. This suggests a rotation of C1 on C2, confirmed (B) by lateral tomograms, which indicate subluxation of the articular surfaces (arrows).

• Fig. 44.30 Crush fracture L1. The interpedicular distance is widened, indicating lateral displacement of the pedicles, and hence 'bursting' of the ring formed by the vertebral body and posterior elements. Water-soluble contrast medium is present in the subarachnoid space.

• Fig. 44.31 Compression fracture: mild crush fracture of the body of T5, with a paraspinal soft-tissue 'mass' (arrows) due to haemorrhage.

• Fig. 44.32 Compression fracture of L2. (A) Plain lateral radiograph indicates wedging of L2, with posterior bulging of the dorsal margin. (B) CT scan demonstrates the extent of the impingement of the dorsal fragment upon the spinal canal.

• Fig. 44.33 Compression fracture L2. (A) Again there is wedging and compression of L2, with evidence of body debris overlying the spinal canal (arrows). (B) CT reconstruction indicates the position of the bone fragments and narrowing of the canal.

• Fig. 44.34 Lap-belt injury: Smith fracture. (A) There are horizontal fractures extending posteriorly from the dorsal surface of the vertebral body, through the pedicles (arrows). (B) The AP view demonstrates the characteristic 'horizontal' defects in the pedicles (arrowheads).

• Fig. 44.35 Lateral compression pelvic fracture classification. (A) Type I . Posteriorly positioned lateral force causes compression of the sacrum, and 'horizontal‘ or buckle fractures of the pubic rami. (B) Type II. The force is delivered more anteriorly, causing inward rotation of the anterior pelvis around the anterior aspect of the sacroiliac joint. Either disruption of the posterior sacroiliac ligaments or fracture of the iliac wing (shown here) results. (C) Type III. The lateral force on one side is transmitted to the contralateral side, causing an externally directed force to 'open' the contralateral pelvis. Disruption of the major anterior ligamentous groups (anterior sacroiliac, sacrotuberous and sacrospinous) occurs. (Reproduced with permission of Urban and Schwartzenberg from Young and Burgess (1987).)

• Fig. 44.36 Type I l ateral compression fracture. A horizontal fracture of the left (closed arrow) and a buckle fracture of the right (open arrows) superior pubic ramus are seen. There is a crush fracture of the left sacrum (long arrows), and a fracture predominantly of the medial wall of the left acetabulum. (Reproduced with permission of Urban and Schwartzenberg from Young and Burgess (1987).)

• Fig. 44.37 Type II B lateral compression fracture. 'Horizontal' fracture of right symphysis, and oblique fracture of the left iliac wing, arising from the sacroiliac joint. There is moderate medial displacement of the left anterior pelvis. (Reproduced with permission of Urban and Schwartzenberg from Young and Burgess (1987).)

• Fig. 44.38 Lateral compression Type III. There are crush fractures of the right sacrum (closed arrow) and left pubic rami. Note diastasis of the left sacroiliac joint (open arrow) and lateral displacement of the whole of the anterior pelvis to the left. Fractures of the right pubic rami are also seen.

• Fig. 44.39 Anteroposterior (AP) compression fracture classification. (A) Type I . Diastasis of the symphysis pubis only. (B) Type II. Diastasis of the symphysis pubis, disruption of the sacrospinous and sacrotuberous ligaments, and anterior sacroiliac ligament. (C) Type III. Total ligamentous disruption, including the posterior sacroiliac ligaments. (Reproduced with permission of Urban and Schwartzenberg from Young and Burgess (1987).)

• Fig. 44.41 Type III AP compression fracture. CT scan demonstrate complete diastasis of the left sacroiliac joint.

• Fig. 44.42 Vertical shear fracture pattern. A superiorly directed force disrupts the left hemipelvis, with diastasis (or fracture) through the left sacroiliac region, and fractures of the pubic rami (or symphysis diastasis). The separated pelvic fragment containing the acetabulum is displaced superiorly. (Reproduced with permission of Urban and Schwartzenberg fromYoung and Burgess (1987).)

• Fig. 44.43 Combined fracture pattern. (A) AP and lateral compression. This type of injury gives fracture patterns of both AP and lateral compression, such as in (B), where there are 'horizontal' fractures of the left pubic rami, indicating lateral compression, but disruption of the left sacroiliac joint, indicating AP compression.

• Fig. 44.44 The so-called 'straddle' fracture is not due to straddling, but, in this case, to AP compression. Diastasis of the left sacroiliac joint indicates a Type III AP compression fracture.

• Fig. 44.45 (A) Posterior acetabular rim fracture shown on CT. There has been a posterior hip dislocation. A characteristic defect described by Richardson et al (1990) is seen in the anterior femoral head (arrow): it is similar to the Hill-Sachs deformity of the humeral head in anterior humeral dislocations. (B) This type of dislocation may lead to post-traumatic avascular necrosis, as shown on this coronal MRI image.

• Fig. 44.46 Posterior acetabular pillar fracture. CT scan demonstrates an extensive fracture of the posterior acetabular pillar, again usually associated with posterior hip dislocation. A fat-fluid level is seen in the joint (arrow), with a small collection of air anteriorly, probably a 'vacuum‘ phenomenon. The cortical femoral head defect is again seen (open arrow).

• Fig. 44.47 Comminuted right acetabular fracture. CT indicates involvement of predominantly the quadrilateral plate, with disruption of the medial articular surface. A fracture through the anterior rim of the left acetabulum is also seen.

• Fig. 44.48 Three-dimensional reformatting of a fracture of the left pelvis and acetabulum, with computerised disarticulation.

• Fig. 44.49 MR image of a superior labral tear of right acetabulum. T1 -weighted image (fat suppression and intraarticular gadolinium) demonstrates irregularity of the superior labrum (arrowhead). (Courtesy of William Conway, MD.)

• Fig: 44.50. Anterior dislocation of the shoulder. (A) The humeral head lies medial and inferior to the glenoid in the subscapular fossa. (B) MR scan (T,-weighting) following reduction of anterior dislocation demostrates an area of decreased signal, indicating subarticular bone 'bruising', possibly leading to the later radiographic appearances of a Hill-Sachs deformity.

• Fig. 44.51 Recurrent anterior dislocation of the shoulder. The characteristic defect is well shown in the axial projection (A). A large defect of this nature can even be visualised clearly in the AP projection, but it is rarely possible to identify small defects on a simple frontal projection; a film in 60° internal rotation or a Stryker view (B) is required.

• Fig. 44.52 (A) Axial fat saturated sequence shows labral disruption as well as an osseous defect in the posterior humeral head, indicating a mild Hill-Sachs deformity not to be confused with the rate Buford complex. (B) where the labrum is absent, with a hypertrophied middle glenohumeral ligament.

• Fig. 44.53 Posterior dislocation of the shoulder. Note the circular appearance of the humeral head and the lack of parallelism between this and the glenoid fossa. The injury followed a severe electric shock causing muscle spasm, which had also precipitated compression fractures of the fifth and sixth thoracic vertebral bodies.

• Fig. 44.54 Luxatio erecta. An unusual inferior dislocation of the humerus, which is 'locked' in abduction.

• Fig. 44.55 Dislocation of the acrornioclavicular joint following a fall on the point of the shoulder. The deformity is accentuated by examination in the erect position with weights being carried in both hands.

• Fig. 44.56 Fracture of the surgical neck of the humerus: axial view. There is marked displacement of the distal humerus, with the comminuted fracture extending into the humeral head.

• Fig. 44.57 MRI rotator cuff injury. Paracoronal (A) and parsagittal (B) Complete tear of supraspinatus, with retraction of the muscle belly and loss of acromiohumeral joint space.

• Fig. 44.58 SLAP injury: T2 -weighted coronal image from MR arthrography demonstrates high signal contrast penetrating a defect in the superior labrum (small arrowhead). Not to be confused with a normal, sublabral recess, into which the tear extends (large arrowhead).

• Fig. 44.59 Supracondylar fracture of humerus. The left humerus is normal; the line extending from the anterior cortex of the shaft passes through the middle third of the capitellum. A similar line on the right cuts the posterior third of the capitellum, indicating the anterior displacement of the fragment. A haemarthrosis of the right elbow joint displaces both fat pads.

• Fig. 44.60 Avulsion of medial epicondyle of the humerus. The centre for the lateral epicondyle has ossified in this child, therefore the medial epicondyle should also have appeared. It is not in its normal location but lies within the medial compartment of the elbow joint.

• Fig. 44.61 Fractures through both forearm bones are seen. Apparent ' shortening' of the distal ulna, with marked angulation, suggests distal radioulnar joint injury.

• Fig. 44.62 Galeazzi fracture. Dislocation of the distal ulna accompanies the radial fracture.

• Fig. 44.63 Monteggia fracture-dislocation. There is a comminuted fracture of the ulna with dislocation of the radial head.

• Fig. 44.64 Fracture of the distal radius with dorsal angulation of the distal fragment. Although frequently referred to as Colles' fracture, the extension of the fracture to the articular surface, seen on the AP view, indicates that this is a Barton's fracture.

• Fig. 44.65 Although commonly referred to as a Smith's fracture, the involvement of the articular surface indicates that this should more correctly be called a reverse Barton's fracture.

• Fig. 44.66 Scaphoid fracture. There is mild cortical irregularity of the waist of the scaphoid. A faint fracture line extends through the waist.

• Fig. 44.67 Normal carpal relationship. The proximal and distal carpal lines define the normal carpal relationship on the PA projection.

• Fig. 44.68 (A) Normal alignment of the wrist allows a continuous line to be drawn through the radius, lunate and capitate. (B) Abnormal alignment: palmar flexion instability (volar intercalary segment carpal instability: VISI). The lunate is rotated towards the palmar surface of the wrist, with the capitate rotated towards the dorsal surface. (C) Dorsiflexion instability (dorsal intercalary segment carpal instability: DISI)-the converse of B.

• Fig. 44.69 (A) In the normal wrist, the scaphoid long axis at approximately 45° (30-60°). (B) Rotatory subluxation: the long axis of the scaphoid is tilted in a volar direction.

• Fig. 44.70 Arcs of injury of the wrist. 1 = The greater arc: pure injury of the greater arc gives rise to a transcaphoid, transcapitate, transhamate and transtriquetral dislocation. 2 = The lesser arc: injury here gives rise to lunate or perilunate dislocation.

• Fig. 44.71 Dislocation of the lunate. In the anteroposterior projection the lunate bone appears to be triangular instead of quadrilateral in shape, and the lateral projection shows clearly that it is displaced forwards. The distal concavity no longer contains the base of the capitate. Because this appearance is perhaps intermediate between a lunate and a perilunate dislocation, it is better referred to as a dorsal midcarpal dislocation. A chip fracture of the proximal scaphoid is also present

• Fig. 44.72 (A,B) Perilunate dislocation of the carpus. With the exception of the lunate, the whole of the carpus has been dislocated dorsally in relation to the radius. Both the radial and ulnar styloid processes have been fractured. Note loss of articulation between lunate and adjacent carpal bones.

• Fig. 44.73 Scapholunate dissociation: 'Terry-Thomas' or 'tooth gap' sign. There is wide separation of the scaphoid and lunate

• Fig. 44.74 Intercarpal ligament disruption: arthrogram. Injection of the radiocarpal joint has resulted in filling of the intercarpal joint as well. Contrast medium is seen passing between the lunate and triquetrum (arrowhead), indicating ligamentous disruption.

• Fig. 44.75 Bennett's fracture-dislocation. The articular surface of the base of the first metacarpal is involved and the main portion of the bone is displaced proximally in relation to the trapezium.

• Fig. 44.76 Boxer's fracture: a fracture of the distal aspect of the fifth metacarpal, with volar angulation of the distal fragment.

• Fig. 44.77 A fracture of the femoral neck may be identified as a lucency interrupting the trabecular pattern, and the femur is externally rotated distal to the fracture.

Fig. 44.78 Injuries of the knee and leg. (A) Supracondylar fracture of the femur with extension to involve the articular surface. (B) Transverse fracture of the patella with wide separation of fragments. (C) Vertical fracture of the patella visible only in the axial projection. (D) Fracture of the lateral condyle of the tibia and neck of fibula. This injury has resulted from forced abduction, with impact of the surface of the lateral femoral condyle upon the tibia. Involvement of the articular surface is minimal and this injury carries a good prognosis. (E) A more severe fracture of the lateral tibial condyle with a crack running downwards into the tibial shaft. This has been caused by complete rupture of the internal lateral ligament and the cruciate ligaments, so that the lateral margin of the femur has impacted upon the surface of the lateral tibial condyle to produce the injury. The articular surface is involved. The neck of the fibula is also fractured. (F) Avulsion injury to extra synovial intercondylar region of tibia.

• Fig. 44.79 MRI of tear. There is a linear area of increased signal extending through the meniscus to the inferior surface. These changes indicate a complete tear.

• Fig. 44.80 MRI of anterior cruciate tear: There is loss of detail of the ligament, which is replaced by an amorphous collection of haematoma and debris

• Fig. 44.81 Posterior cruciate tear: There is loss of detail, and structure of the ligament.

• Fig. 44.82 Meniscal cyst: MRI (T2 -weighted). There is increased signal in a well-defined fluid collection (arrow) arising from the medial meniscus.

• Fig. 44.83 Bone 'bruising' of the femoral condyle, following knee dislocation. MRI gradient-echo image, showing the typical appearances of a focal area of increased signal.

• Fig. 44.84 Diagram of the major varieties of injuries of the ankle. (A) Adduction/inversion injury of the ankle. The fracture on the tension side (lateral malleolus) is transverse. The medial malleolar fracture is oblique. (B) Additional external rotation gives rise to an oblique or spiral fracture of the fibula ± fracture of the posterior aspect of the tibial plafond. (C) Abduction (eversion) injury. The fracture on the tension side (medial malleolus) again is transverse; with external rotation, fracture of the posterior aspect of the tibial plafond may occur, as shown. (D) Forced dorsiflexion. Comminution of the tibial plafond is expected, particularly involving the anterior aspect.

• Fig. 44.85 MRI of the ankle: rupture of the Achilles tendon. There is gross irregularity, and widening of the tendon above its insertion, with areas of increased signal, within and surrounding the tendon sheath. Normal low-signal-intensity tendon is not present in the expected region, due to muscle retraction.

• Fig. 44.86 (A,B) Fracture-dislocation of the talus. There is a fracture through the waist of the talus, with complete dislocation of the posterior fragment.

• Fig : 44.87. Fracture of calcaneus. The normal angle formed between the subtalar joint and the upper margin of the tuberosity of the calcaneus should be about 40 degree. Diminution of this angle arouse suspicion of a fracture , but this may only be clearly shown in the axial projection. (A). Normal Bohler’s angle measurement. (B) Increased angle with fracture of body of calcaneus.

• Fig: 44.88. Lisfranc fracture dislocation. There are fractures through the medial cuneiform, and bases of the second and third metatarsals, with lateral displacement of the first, second, third and fourth metatarsals.

• Fig: 44.89. Dislocation of the thumb, missed at initial reading by emergency staff. There is apparently normal alignment on the AP and oblique views (A,B). However careful inspection of the lateral view (C) demonstrates malpositioning of the metacarpal, which has dislocated dorsal to the trapezium.

• Fig. 44.90 Radial collateral ligament avulsion of the thumb. Lateral radiograph shows some irregularity of the radial aspect of the base of the proximal phalanx of the thumb, missed on initial interpretation, possibly being mistaken for a sesamoid bone.

• Fig. 44.91 Scaphoid fracture, not seen on the initial radiographs (A). Dedicated scaphoid view (B) clearly demonstrates the fracture.

• Fig. 44.92 Minor stress fracture in the ankle: T,-weighted coronal images (A/A and T2-weighted image B demonstrate areas of linear abnormal signal within the inferior talus and superior calcaneous of this young gymnast with ankle pain. These are areas of linear decreased signal intensity on T, sequences, with markedly increased intensity or the T 7 sequences, indicating acute focal oedma.