Chapter 15: Trauma, Mobile, and Surgical Radiography

C-arm Orientation and Exposure Patterns

30 deg. c-arm tilt - increased exposure to face and neck by a factor of FOUR

Dislocation

Displacement of bone from the joint, no longer in contact with its normal articulation - movement painful and must be avoided - imaged in 2 planes: -- Shoulder dislocation -- Other common: fingers, patella, hip

Boxers fx

Distal 5th metacarpal, seen on lateral, punching

Anatomic apposition

End to end contact

Lack of apposition

Ends to aligned but separated

Trauma principle 2

Entire structure or trauma area on IR - initial long bone studies require that BOTH joints be demonstrated for each projection - follow-up studies usually require ONLY the joint nearest the injury

Mallet or baseball fx

Injury is caused by forcibly flexing the DIP joint during active extension. Striking the fingertip when attempting to catch a ball

Contusion

A "bruise" type injury without a fracture or break in the skin

lateral humerus

CR parallel to epicondyles

AP shoulder

CR perpendicular to shoulder joint

Varus angulation

Toward midline, apex angulation lateral

Butterfly

two oblique fracture lines meeting to create a large triangular or wedge-shaped fragment located between the proximal and distal fracture fragments, and resembles a butterfly wing

non sterile field

where the technologist as well as other non sterile surgical personnel such as the anesthesiologist and the circulation is located

external fixation

fracture-stabilizing device permits bone healing without the immediate requirement for internal fixation - severe open fractures, comminuted closed fractures, arthrodesis, infected joints, and major alignment and length deficits - ilizarov device: correct length deficit - pelvic external fixator

Depressed fx

ping-pong fx. fx of skull where a fragment is depressed

Smiths fx

(reverse colles) fx anterior displacement

Complete fractures

- (Two pieces) - transverse fracture - oblique fracture - spiral fracture

Trauma adaptation positioning: principle 1

- 2 projections 90 deg. from each other - often with no patient movement -adapt CR angles and IR placement to minimize further injury or discomfort to the patient

Trauma AP skull

- AP: 0 deg., CR parallel to OML, CR to glabella - AP "reverse caldwell" : CR 15 deg cephalic to OML, CR to nasion

AP and and lateral knee

- AP: no CR angle for average patient - Lateral: Horizontal CR parallel to epicondyles

Lumbar laminectomy/fusion

- C-arm set up for AP projection (patient prone) - C-arm alignment for lateral projection

HIp pinning procedures

- C-arm setup with fx table - Shower curtain separates sterile from non sterile areas - C-arm alignment for lateral hip (recommended c-arm position, intensifier near surgeon) - C-arm alignment with X-ray tube near surgeon (not recommended)

Trauma AP axial projection

- CR 30 deg caudal to OML - CR to level of EAMs

Modified AP waters

- CR parallel to LML - CR enters acanthion - Petrous ridges in mid aspect of maxillary sinuses - best demonstrates floor of orbits and entire orbital rims

AP reverse waters

- CR parallel to MML - CR enters acanthion - Petrous ridges just below maxillary sinuses

Trauma lateral skull

- CR: 2 inches superior to EAM - No tilt or rotation - No suspected C-spine injury - w/o head manipulation

AP supine abdomen

- CR: at iliac crest

Lateral Scpaular Y

- CR: cross angled if required - grid crosswise

AP humerus

- CR: perpendicular to epicondyles - Include both joints

Alternative imaging modalities

- CT: fast, accurate, 3D capabilities - Ultrasound: blunt injury, free air/fluid, pregnancy/ectopic - Nuclear medicine: PE, blood flow - Angiography and interventional procedures: AO arch, embolize hemorrhage

Trimalleolar fx

- Common in accidents where a huge force is applied on the ankle, like skiing sports or an automobile accident - common in aging populations, who are active - Osteoporosis also increase the risk

Incomplete fracture

- Fracture does not transverse through entire bone - Examples: Torus, greenstick, plastic

Transthoracic lateral proximal humerus

- Horizontal CR to surgical neck and centerline of grid - Raise unaffected arm above head, elevating the unaffected shoulder

Trauma axiolateral projections of elbow

- Projection for radial head- CR: angled 45 deg. toward shoulder - Projection for coronoid process- CR: angled 45 deg. away from shoulder

Stellate fracture

- This # occurs in the flat bones of the skull and patella - Fracture lines run in various directions from one point - Star like

Principle 1 exceptions

- barriers to true AP and lateral (splints, traction bars, etc.) - Exceptions to true CR-part-IR alignment

Hutchinson fx

- chauffeur's fx -radial styloid process (hand cranked cars)

General types of fractures

- complete - comminuted - impacted

Horizontal beam projections

- divergency of xray beam - ensure that body part is not projected off IR

Evaluation criteria: OC

- entire biliary ducts filled and demonstrated - no motion - optimal exposure factors

Stress or fatigue fx

- non-trauma - overuse or repetitive activity injury - occurs when muscles become fatigued and are unable to absorb added shock - eventually, fatigued muscle transfers the overload of stress to the bone causing a tiny crack - marching: Midshaft of metatarsals (or knee) - running: distal shaft of tibia possibly hip

Radiation protection with C-arm

- place X-ray tube under table to reduce head and neck exposure to operator - minimize use of boost exposure - minimize distance between anatomy and image intensifier - provide lead aprons for those remaining inure not behind lead shields

Scrub

- prepares and maintains sterile surgical field and instruments - gowns members of surgical team

Surgical Attire Technologist

- scrubs - shoe covers - non sterile gloves - protective apron - head cover - surgical mask

Left lateral decubitus

- support board or sufficient pads - CR 1-2 in. above iliac crest - NO R. lateral - arms above head - Allows determination of air- fluid levels and possible free intra-abdominal air

Lateral decubitus chest

- to determine air-fluid levels - radiolucent pads under shoulders and hips - arms above head - CR: 3-4 in. below jugular notch, level of T7

Mobile and trauma radiography

- trauma patient on stretcher - mobile (portable) chest procedure

Dorsal decubitus (lateral) projection

- useful projection to rule out possible abdominal aortic aneurysm - CR: iliac crest

Protecting the sterile environment: 3 methods

1. draping c-arm 2. draping patient 3. shower curtain

3 cardinal principles of radiation

1. distance 2. time 3. shielding

Types of proximal femur fractures

1. femoral neck 2. comminuted subtrochanteric 3. intertrochanteric

Surgical team

1. surgeon 2. Certified surgical tech (CST) 3. Radiologic technologist 4. Scrub (CST or RN)

Fracture

A break in the bone

Splintered

A comminuted fracture characterized by shattered fragments of sharp bone

Potts fracture

Ankle fracture of distal fibula with frequent fracture of medial malleolus. Major injury and ligament tears - common term for bimalleolar fx

Bennetts fx

Base of 1st metacarpal, CMC jt

mobile (portable) xray equipment: Type 1

Battery powered, battery driven - 10-16 rechargeable 12V batteries - speed 2.5 to 3 mph (maximum incline 7 deg.) - recharged with 110V or 120V source - 8 hours to charge if fully discharged

Avulsion fractures

Bone attached to tendon or ligament pulls the piece of bone away

Lateral Elbow

CR: parallel to interepicondylar plane

PA elbow

CR: perpendicular to interepicondylar plane

Operative Cholangiogram

Conventional mobile x-ray unit positioned for AP projection - centering point indicated by surgeon

Apposition

Describes how the fragmented ends of the bone make contact with each other - types: Anatomic, Lack of apposition, bayonet

Colles fx

Distal radius, posterior displacement, usually forward fall

internal fixation

During open education fractures, a variety of compression plates, screws, pins, intramedullary rods, nails, or wires applied to reduce or realign the fracture - these devices are left in place and the skin is closed around the device

Sprain

Forced wrenching or twisting of a joint, resulting in partial rupture or tearing of supporting ligaments

Bayonet apposition

Fragments overlap, shafts make contact, not ends

C-arm Orientation and Exposure Patterns

Horizontal - Increased exposure at xray tube end

Angulation

Loss of alignment

Trauma principle 3

Maintain the safety of the patient, health care workers, and the public - all equipment returned to original position (or better!) - never exposure with unshielded person in vicinity of primary beam - ALARA applies to everyone

mobile (portable) xray equipment: Type 3

Mobile C-arm Fluoro - induces: -- c-arm with xray tube and image intensifier -- TV monitors (2) - features: -- digtal imaging and storage -- image hold feature -- image enhancement, masking, and subtraction

Impacted fracture

One fragment driven into another (ends of bones)

Subluxation

Partial dislocation of joint - C-spine (C5 vertebra displaced posteriorly) - Nursemaids elbow: an example of partial dislocation of radial head (kids)

mobile (portable) xray equipment: Type 2

Standard power - source (110 or 220 V) - capacitor discharge (not common) - much lighter, usually not motor driven - stores electrical charge for greater electrical power upon making exposure

Segmental fracture

The bone is broken in two places, which leaves at least one bone segment floating and unattached

Comminuted fractures

Two or more fragments - segmental - butterfly - splintered

Compression fracture

Vertebral body collapses or is crushed

C-arm Orientation and Exposure Patterns

Vertical AP orientation (left) - should be avoided, increased exposure to head and neck

C-arm Orientation and Exposure Patterns

Vertical PA (right) - least exposure to operator

Valgus angulation

away from midline, apex angulation medial

Simple fracture

bone does not break through skin (closed fracture)

Compound fracture

bone protrudes through skin

Attributes of the Surgical Technologist

confidence, mastery, problem-solving skills, communication

Retrograde urography

conventional cystic table and x-ray unit - nonfunctional examination of the urinary system during which contrast medium is introduced directly retrograde (backward, against the flow) into pelvicalyceal system via catheterization - performed to determine the location of undetected calculi or other types if obstruction in urinary system

Apex angulation

describes the direction or angle of the apex of the fracture - Varus - Valgus

Baseball fx

distal phalanx, ball hitting fingers

Bartons fx

distal radius

Pathologic fx

fracture due to bone disease process - osteoporosis - bone cancer

intramedullary fixation

intermedullary rods and nails are inserted within the shaft of long bones to stabilize fractures - this technique is popular for reducing shaft fractures of the humerus, tibia and femur

Hip fractures and pinning

internal fixation of fractured hip with cannulated screws (for nondisplaced femoral neck fractures)

Chip fx

like avulsion but no tendon involvement

Sterile field

patient, surgical field, surgeon and surgical assistants, surgical equipment, tables and carts

Hangman fx

pedicles of C2

Monteggia fracture

proximal ulna along with dislocation of radial head, from defensive move of raising forearm

Weak, ill and injured patients

requires adaption in positioning and care - mobile - immobilized-backboard, splints, collars - often done supine - stationary grids

Surgical asepsis

separation between sterile and non sterile areas