Quiz #2 Flashcards
Foot
- Considerable differences in thickness
- Consists of 26 bones divided into three parts:
- Tarsus or tarsal bones
- Metatarsals (bones of the “instep”)
- Phalanges
Phalanges
- 14 phalanges
- Two in the great toe; three in each of other four toes
- Named by location
- The interphalangeal (IP) joints also named by location
- IP joints are synovial, diarthrodial hinge type
Metatarsals
- Five metatarsals numbered one to five beginning at the medial aspect, or great toe side
- Consist of body (shaft) and two articular extremities
- Proximal end – base
- Distal end – head
- Distal ends (heads articulate with proximal phalanges)
- Metatarsophalangeal (MTP) joints
- MTP joints classified as ellipsoidal-type joints
Tarsals
- Seven tarsal bones of the ankle
- Calcaneus (os calcis) – bone of the heel
- Talus
- Navicular
- Cuboid
- Three cuneiforms differentiated medially to laterally as first, second, and third or internal, middle, and external
Calcaneus
- Largest tarsal bone
- Usually examined separate from the foot, if injured
Talus
- Occupies the highest position and is second largest
- The talus articulates with the calcaneus at the “subtalar” joint
Cuboid
- On lateral side between calcaneus and the fourth and fifth metatarsals
Navicular
- On medial side between calcaneus and the cuneiforms
Cuneiforms
- Named by location
- Medial
- Intermediate
- Lateral
- Occupy the central and medial aspect of the foot between the navicular and the first, second, and third metatarsals
- Medial cuneiform is the largest
- Intermediate is the smallest
Tarsals
- Mneumonic can aid in remembering tarsal names:
- Chubby - Calcaneus
- Twisted - Talus
- Never - Navicular
- Could - Cuboid
- Cha Cuneiform—medial
- Cha Cuneiform—intermediate
- Cha Cuneiform—lateral
Ankle joint
- The ankle joint is formed by articulation between the talus tarsal and the:
- Lateral malleolus of fibula
- Inferior surface of tibia
- Medial malleolus of tibia
- Classified as a synovial, hinge-type joint; allows flexion and extension
Ankle
- The slight adduction/abduction and rotation motions of the ankle result from the intertarsals’ gliding movements rather than the ankle joint proper
Sesamoid bones
- Small detached bones found in the foot
- Usually form in points of stress near a joint
- Usually found on posterior (plantar) surface of first MTP joint
- Is possible to fracture one or both because of plantar location
- Very painful when fractured
Patient preparation
- Remove artifacts from anatomy of interest
- Shoes
- Socks or hose (elastic = artifact)
- Heavy fabric (e.g., denim) rolled above anatomy of interest
Patient position
- Ambulatory patients
- Seated on x-ray table
- Affected limb rests on the IR placed on the tabletop
- Nonambulatory patients
- Alter positioning to maximize patient comfort
- Transfer from stretcher to table is not necessary
IR and SID
Image Receptor
- 10” x 12” IR collimated to the specific part
Source to Image Distance
- 40”
ID markers
- Right or left side markers must be included on at least one of the projections on an IR
- Avoid using digital annotation to place side markers on images
- Other required ID markers must be in the blocker or elsewhere on the final image
Radiation protection
Shield ALL patients
Patient Instructions
- Explain and demonstrate positions
- Breathing instructions not required for distal lower limb procedures
Essential toe projections
- Anteroposterior (AP) or AP axial
- AP oblique
- Lateral (mediolateral or lateromedial)
- All use same collimated field size
- 1” on all sides of the toes, including 1” proximal to the MTP joint
AP or AP axial toes
- AP axial recommended to open the joint spaces and reduce foreshortening
- Part position
- Knee flexed with sole of foot on IR
- Toes centered to IR
- May be elevated on a 15-degree wedge sponge for axial
- Long axis of foot aligned parallel
- Central ray (CR)
- AP
- Perpendicular to IR
- Axial
- Angled 15 degrees posteriorly
- May be perpendicular if toes are elevated on 15-degree wedge sponge
- AP
AP oblique toes: Medial rotation
- Part position
- Knee flexed
- Leg and foot medially rotated enough to place plantar surface of foot at 30- to 45-degree angle from plane of IR
- Center toes to IR
- CR
- Perpendicular to third MTP joint
Lateral: Great and second toe
- Patient position
- Lateral recumbent on unaffected side
- Part position
- Lateral with gauze separating toe of interest from others
- Tape other toes in flexion
- CR
- Perpendicular to MTP joint of great toe
- Perpendicular to proximal interphalangeal (PIP) joint of second toe
Lateral: Third to fifth toes
- Patient position
- Lateral recumbent on affected side
- Part position
- Lateral
- Separated from other toes with immobilization
- CR
- Directed perpendicular to PIP joint of affected toe
Foot projections
- AP or AP axial
- AP oblique (medial rotation)
- AP oblique (lateral rotation)
- Lateral (mediolateral)
AP or AP axial foot
- The axial projection demonstrates the tarsometatarsal joint spaces better and reduces foreshortening
- Part position
- Flex knee, and rest plantar surface of foot on IR
- Leg vertical
- Long axis of foot aligned parallel
- CR
- AP
- Perpendicular to base of third metatarsal
- AP axial
- Angled 10 degrees toward heel to the base of the third metatarsal
- AP
- Collimated field
- 1” on the sides and 1” beyond the calcaneus and distal tip of the toes
AP oblique foot: Medial rotation
- Part position
- Knee flexed
- Leg and foot rotated medially enough to place plantar surface 30 degrees from IR
- Align long axis of foot parallel
- Foot centered to middle of IR
- CR
- Perpendicular to base of third metatarsal
- Collimated field
- 1” on the sides and 1” beyond the calcaneus and distal tip of the toes
AP oblique foot: Lateral rotation
- Part position
- Knee flexed
- Leg and foot rotated laterally enough to place plantar surface 30 degrees from IR
- Align long axis of foot parallel
- Foot centered to middle of IR
- CR
- Perpendicular to base of third metatarsal
- Collimated field
- 1” on the sides and 1” beyond the calcaneus and distal tip of the toes
Lateral foot
- Patient position
- Recumbent on table
- Turned toward affected side until leg and foot are lateral
- Part position
- Elevate knee to place patella perpendicular to table
- Center foot to IR
- Align long axis of foot parallel
- Dorsiflex foot to 90 degrees from leg
- CR
- Perpendicular to base of metatarsals
- Collimated field
- 1” on all sides of the shadow of the foot, including 1” proximal to the medial malleolus
Calcaneus projections
- Axial (plantodorsal)
- Lateral (mediolateral)
Axial (plantodorsal) Calcaneus
- Part position
- Leg extended
- Ankle in right-angle dorsiflexion
- Support may be needed
- Ankle centered to IR
- CR
- 40 degrees cephalic
- Enters plantar surface at base of third metatarsal
- Collimated field
- 1” on three sides of the shadow of the calcaneus
Lateral calcaneus
- Patient position
- Resting on affected side
- Leg almost lateral
- Part position
- Calcaneus centered to IR
- Long axis aligned with IR
- CR
- Perpendicular to calcaneus
- Center 1” distal to medial malleolus at subtalar joint
- Collimated field
- Adjust collimator to 1” past the posterior and inferior shadow of the heel
- Include medial malleolus and base of the fifth metatarsal
Ankle projections
- AP
- Lateral (mediolateral)
- AP oblique Medial Rotation
- Ankle
- Mortise joint
- AP Oblique Lateral Rotation
- AP (stress)
AP ankle
- Part position
- Leg extended
- Ankle centered to IR
- Ankle flexed to place long axis of foot vertical
- CR
- Perpendicular through ankle to midway between the malleoli
- Collimated field
- 1” on the sides of the ankle and 8” lengthwise to include the heel
Lateral ankle
- Patient position
- Turned toward affected side
- Place leg and ankle in lateral position
- Part position
- Center ankle to IR
- Dorsiflex foot to right angle
- CR
- Perpendicular to ankle joint
- Enters medial malleolus
- Collimated field
- 1” on the sides of the ankle and 8” lengthwise
- Include the heel and the fifth metatarsal base
AP oblique ankle: Medial rotation
- Part position
- Leg extended
- Ankle centered to IR
- Foot dorsiflexed to right angle
- Leg and foot rotated medially 45 degrees
- CR
- Perpendicular to ankle joint, midway between the malleoli
- Collimated field
- 1” on the sides of the ankle and about 8” lengthwise to include the heel
AP oblique: Mortise joint
- Part position
- Leg extended
- Ankle centered to IR
- Foot dorsiflexed to right angle
- Leg and foot rotated medially 15 to 20 degrees
- Intermalleolar plane parallel with IR
- CR
- Perpendicular to ankle joint, entering midway between malleoli
- Collimated field
- 1” on the sides of the ankle and about 8” lengthwise to include the heel
AP oblique ankle: Lateral rotation
- Part position
- Leg extended
- Ankle centered to IR
- Foot dorsiflexed to right angle (plantar surface vertical)
- Leg and foot rotated laterally 45 degrees
- CR
- Perpendicular to ankle joint, midway between the malleoli
- Collimated field
- 1” on the sides of the ankle and about 8” lengthwise to include the heel
AP (stress) ankle
- Stress is used to verify ligamentous tears
- Part position
- Same as for AP
- Physician places foot in extreme inversion and eversion positions
- Immobilization of stress position is needed for each exposure
AP or AP axial toes
- Evidence of proper collimation
- Entire toes, including distal ends of the metatarsals
- Toes separated from each other
- No rotation of phalanges; soft tissue width and midshaft concavity equal on both sides
- Open IP and MTP joint spaces on axial projections
- Soft tissues and bony trabecular detail
AP oblique toes
- Evidence of proper collimation
- Entire toes, including distal ends of the metatarsals
- Toes separated from each other
- Proper rotation of toes, as demonstrated by more soft tissue width and more midshaft concavity on elevated side
- Open IP and second through fifth MTP joint spaces
- First MTP joint (not always opened)
- Soft tissue and bony trabecular detail
Lateral toes
- Evidence of proper collimation
- Entire toe, without superimposition of adjacent toes; when superimposition cannot be avoided, the proximal phalanx must be shown
- Toe(s) in a true lateral position
- Toenail in profile, if visualized and normal
- Concave, plantar surfaces of the phalanges
- No rotation of the phalanges
- Open IP joint spaces; the MTP joints are overlapped but may be seen in some patients
- Soft tissue and bony trabecular detail
AP or AP axial foot
- Evidence of proper collimation
- Anatomy from toes to tarsals; may include portions of talus and calcaneus
- No rotation of the foot, as demonstrated by equal amounts of space between the second through fourth metatarsals
- Overlap of the second through fifth metatarsal bases
- Axial projection resulting in improved demonstration of IP, MTP, and TMT joint spaces
- Open joint space between medial and intermediate cuneiforms
- Soft tissue and bony trabecular detail
AP oblique foot: Medial rotation
- Evidence of proper collimation
- Entire foot, from toes to heel
- Proper rotation of foot
- Third through fifth metacarpals free of superimposition
- Bases of the first and second metatarsals superimposed on medial and intermediate cuneiforms
- Navicular, lateral cuneiform, and cuboid with less superimposition than in the AP projection
- Tuberosity of the fifth metatarsal
- Lateral TMT and intertarsal joints
- Sinus tarsi
- Soft tissue and bony trabecular detail
AP oblique foot: Lateral rotation
- Evidence of proper collimation
- Entire foot, from toes to heel
- Proper rotation of foot
- Third through fifth metacarpals free of superimposition
- Minimal superimposition between medial and intermediate cuneiforms
- Navicular seen with less forshortening than in the medial rotation AP oblique projection
- Soft tissue and bony trabecular detail
Lateral foot
- Evidence of proper collimation
- Entire foot and distal leg
- Superimposed plantar surfaces of the metatarsal heads
- Fibula overlapping the posterior portion of the tibia
- Tibiotalar joint
- Soft tissue and bony trabecular detail
Axial calcaneus
- Evidence of proper collimation
- Calcaneus and subtalar joint
- No rotation of the calcaneus—the first or fifth metatarsals not projected to the sides of the foot
- Anterior portion of the calcaneus with brightness similar to the posterior portion
- Two images may be needed for the two regions of thickness
- Soft tissue and bony trabecular detail
Lateral calcaneus
- Evidence of proper collimation
- Entire calcaneus, including ankle joint and adjacent tarsals
- No rotation of the calcaneus
- Tuberosity in profile
- Sinus tarsi open
- Calcaneocuboid and talonavicular joints open
- Soft tissue and bony trabecular detail
AP ankle
- Evidence of proper collimation
- Ankle joint centered to exposure area
- Medial and lateral malleoli
- Talus with proper density
- No rotation of the ankle
- Normal overlapping of the tibiofibular articulation with the anterior tubercle slightly superimposed over the fibula
- Talus slightly overlapping the distal fibula
- No overlapping of the medial talomalleolar articulation
- Tibiotalar joint space
- Soft tissue and bony trabecular detail
Lateral ankle
- Evidence of proper collimation
- Ankle joint centered to exposure area
- Distal tibia and fibula, talus, calcaneus, and adjacent tarsals
- Ankle in true lateral position
- Tibiotalar joint well visualized, with the medial and lateral talar domes superimposed
- Fibula over the posterior half of the tibia
- Fifth metatarsal base and tuberosity should be seen to check for Jones fracture
- Brightness and contrast of the ankle sufficient to see the outline of distal portion of the fibula
- Soft tissue and bony trabecular detail
AP oblique ankle: Medial rotation
- Evidence of proper collimation
- Ankle joint centered to exposure area
- Distal tibia, fibula, and talus
- Proper 45-degree rotation of ankle
- Tibiofibular articulation open
- Distal tibia and fibula overlap some of the talus
- Soft tissue and bony trabecular detail
AP oblique: Mortise joint
- Evidence of proper collimation
- Entire ankle mortise joint centered to exposure area
- Distal tibia, fibula, and talus
- Proper 15- to 20-degree rotation of ankle
- Talofibular articulation open
- Tibiotalar articulation open
- No overlap of the anterior tubercle of the tibia and the superolateral portion of the talus with the fibula
- Soft tissue and bony trabecular detail
AP oblique ankle: Lateral rotation
- Evidence of proper collimation
- Ankle joint centered to exposure area
- Ankle joint from toes to tarsals; may include talus and calcaneous
- Proper 45-degree rotation of ankle
- Tibiofibular articulation open
- Distal tibia and fibula overlap some of the talus
- Soft tissue and bony trabecular detail