imaging in Appendicular and Pelvic Trauma.pptx

Radiological imaging features of trauma in the setting of appendicular skeleton and the pelvic bones. detailed imaging and protocols for management.

1. Appendicular and Pelvic Trauma

2. Adult Fracture Patterns Complete Fractures traversing cortices separating a bone into two parts Incomplete fractures only demonstrated on MRI Orientation. A fracture may be transverse, oblique or spiral. defines stability, probability of displacement, mechanism of injury Location. Reference to the epiphyseal, metaphyseal and diaphyseal regions diaphysis can be considered in thirds

3. Distraction, impaction and angulation. The bone ends may be aligned and opposed, displaced or off-ended Impacted fractures often present as hyperdense lines Angulation can be described, either by the orientation of the bone distal to the fracture line or by the direction at the apex of the fracture Articular involvement influence the operative approach often associated with soft tissue injury and instability Soft tissue features Lipohaemarthroses and joint effusions are indicators of intra-articular injury and fracture capsular disruption will result in dissolution of an effusion.

4. Types of Occult Fracture Occult-Complete Fractures Persistent symptoms over a period of 2 weeks that are unrelenting disproportionate symptoms in the context of normal plain radiography Occult-Incomplete Fractures frequently stable but may require immobilisation or reduced weight bearing Bone Bruising Only visible on MRI (increased STIR signal) overloading causing trabecular compression and microfractures diffuse type - widespread ill-defined area of marrow oedema in the epimetaphyseal region focal or geographic type - sub-articular in type and more well-defined

5. Avulsion Fractures occur at sites of tendon, ligament or capsular attachments due to tractional force applied by the soft tissue structures should not include fragmentation and impaction injuries due to muscle contraction - usually encountered in muscle groups crossing two joint lines Ligamentous avulsion - extreme distraction or angulation of the joint a bone fragment or entire apophysis from the underlying bone may be avulsed.

6. Paediatric Fractures- Morphological Types Plastic bowing fracture deformity and malalignment may persist but there is no discrete fracture line Buckle (torus) fracture buckling of the cortex and periosteum along the concave side of the fracture Green stick fracture progression beyond the torus injury. buckling of the cortex as described for a torus injury with interruption of the cortex on the convex side

7. Growth Plate Injuries classification described by Salter and Harris Type 1 to type 5 progressive increase in the risk of complication and potentially premature fusion of the growth plate

8. THE SHOULDER consists of two separate joints: glenohumeral (GH) joint with a ball and socket configuration and the relatively immobile acromio -clavicular (AC) joint GH joint is the most frequently dislocated joint a modified 40-degree axial oblique is preferred in suspected injuries to exclude dislocation ‘Y’ lateral view is preferable for suspected scapula fractures

9. Anterior Dislocation Mc type - 95% humeral head usually dislocates anteroinferiorly Associated injuries identifiable on radiographs include: Hill-Sachs lesion – wedge or ‘hatchet-shaped’ defect in the posterosuperior region of the humeral head Bony Bankart lesion – represents a variably sized triangular fragment sheared off the antero-inferior aspect of the glenoid due to impaction of the humeral head. high probability of re-dislocation exists with fragments greater than 5 mm in depth and width. identifiable as small bone fragments on post reduction AP and axial views Greater tuberosity avulsions - result from traction/avulsion by the attachment of supraspinatus

10. Posterior Dislocation frequently associated with generalised ligamentous laxity and multidirectional instability humeral head is internally rotated and appears as a ‘light-bulb’ in shape, as the head is viewed en face on the AP view reverse Hill-Sachs defect in the anterosuperior humeral head and posterior glenoid fractures

11. Luxatio Erecta humeral head is dislocated inferiorly as a result of extreme hyper-abducting force. This injury has the highest risk of neurovascular, ligament and rotator cuff injuries Fractures of the proximal humerus in old age ligament injury or dislocation in younger Fracture follows the line of the fused growth plates, affecting the greater tuberosity, lesser tuberosity, and the Surgical and Anatomical necks of the humerus

12. classification of proximal humeral fractures based upon the extent of displacement (>1 cm), rotation (>45 degrees) and the number of fragments. multiple-part fracture of the humeral head, which is undisplaced , is classified as a Neer ‘1 part’ fracture Fracture if minimally displaced, are not considered as separate fragments Two-, three- and four-part fractures are seen with fractures involving, respectively, the greater and lesser tuberosities in addition to the surgical neck.

13. Transverse fractures of the humerus involve either the surgical neck or shaft inferior to this Shaft fractures are more often spiral Medial displacement of the humeral shaft proximal to the fracture occurs due to the pull of pectoralis major muscle If the joint surfaces are congruent post reduction, but an articular offset exists, MRI is indicated to exclude interposition of soft tissues, usually subscapularis, or the long head of biceps within the joint space

14. ACROMIO-CLAVICULAR JOINT Clavicle fractures are very common - middle third (80%), outer-third 15 % and medial third 5% AC joint is held in place by the AC ligament and the two coraco -clavicular (CC) ligaments - conoid and trapezoid inferior cortex of both the clavicle and the acromion should align normal distance between the superior surface of the coracoid and the inferior clavicle is 13 mm Disruptions are graded from type 1 to type 6 by Rockwood Grade 1 is a sprain of the ligaments grade 2 - AC joint ligaments are torn but the CC ligaments are intact

15. THE ELBOW fat pad sign- fluid displaces the normal anterior and posterior fat pads away from the humerus in trauma. Identified as lucent areas. A visible posterior fat pad is always abnormal Supracondylar fracture is mc in children and radial head fracture in adults On a lateral radiograph a line drawn down the anterior humeral cortex will pass through the capitellum so that at least one-third of the capitellum lies anterior to the line If it is broken then it is likely that there is a subtle Greenstick or Salter–Harris growth plate injury

16. Lateral epicondyle fractures Recognition made difficult by the presence of developing ossification centers order of appearance - capitellum, radius, internal epicondyle, trochlea, olecranon and lateral epicondyle – CRITOL although there may only be a small bony component to this injury, there will be a large fracture through the growing cartilaginous distal humerus

17. Medial epicondyle fractures result of an avulsion force by the attachment of the common flexors Widening of the growth plate should be looked for. The apophysis may be displaced Dislocation of the radial head detected by the use of radio-capitellar line It should pass through the capitellum on every view; if not, the radial head is dislocated

18. a fracture of the ulnar shaft is often associated with a dislocation of the radial head at the elbow - Monteggia fracture dislocation radial shaft fracture associated with a dislocation of the ulna at the wrist and is known as a Galeazzi fracture dislocation

19. Elbow fractures in adults displaced capitellum has an appearance like a half moon and is seen lying antero-superior to the forearm bones Radial head fractures may involve the radial neck only or may be intra-articular, with disruption of the radial articular surface commonest ulnar fracture is of the olecranon and involves the articular surface with the proximal fracture fragment often displaced by pull of triceps Coronoid fractures of the ulna are uncommon but are often associated with elbow dislocation