Radiographic Procedures II - Toes, Foot, Heel & Ankle PDF

Toes, Foot, Heel, & Ankle Jena Heflin, MBA, RT(R), CMOM  Consists of 26 bones ◦ 14 phalanges (bones of the toes) ◦ 5 metatarsals (bones of the instep) ◦ 7 tarsals (bones of the ankle)  Three divisions of the foot ◦ Forefoot Metatarsals & Phalanges (Toes) ◦ Midfoot 5 Tarsals: 3 cuneiforms, navicula...

Toes, Foot, Heel, & Ankle Jena Heflin, MBA, RT(R), CMOM  Consists of 26 bones ◦ 14 phalanges (bones of the toes) ◦ 5 metatarsals (bones of the instep) ◦ 7 tarsals (bones of the ankle)  Three divisions of the foot ◦ Forefoot Metatarsals & Phalanges (Toes) ◦ Midfoot 5 Tarsals: 3 cuneiforms, navicular, & cuboid ◦ Hindfoot Talus & Calcaneus  Surfaces of the Foot ◦ Dorsum or Dorsal Surface ◦ Superior surface of the foot ◦ Plantar Surface ◦ Inferior surface of the foot  Arches of the Foot ◦ Longitudinal  Shock absorber  Weight bearing  Permits smooth walking  Medial more pronounced ◦ Transverse  Runs side-to-side  Supports the longitudinal arch  Cuneiforms & Cuboid  Dorsiflexion ◦ Flex ankle joint; pointing foot upward  Plantar Flexion ◦ Extend ankle joint; pointing foot downward  Inversion (Varus) ◦ Turning inward  Eversion (Valgus) ◦ Turning outward  14 Phalanges ◦ Two in the great toe distal & proximal ◦ Three each in 2nd - 5th toe distal, middle, & proximal  Each phalanx composed of a body, base, and head ◦ Base is proximal ◦ Head is distal  Compared to phalanges of the hand, phalanges of the foot are smaller and have limited movement Head Base       Numbered 1 – 5 starting from the medial side of the foot Consists of a body, base, and head ◦ Base is proximal ◦ Head is distal 5 heads form the “ball” of the foot 1st metatarsal is shortest and thickest 2nd metatarsal is longest 5th metatarsal contains a prominent tuberosity prone to fracture  Joints of the Phalanges ◦ Interphalangeal (IP) Joint: 1st digit only  Between proximal and distal phalanges ◦ Distal Interphalangeal (DIP) Joint: 2nd-5th digits  Between middle and distal phalanges ◦ Proximal Interphalangeal (PIP) Joint: 2nd-5th digits  Between proximal and middle phalanges  Joints of the Metatarsals ◦ Metatarsophalangeal (MTP) Joint  Located at heads of metatarsals ◦ Tarsometatarsal (TMT) Joint  Located at bases of metatarsals ***ALL of the joints of the foot are classified as Synovial Joints  Seven Tarsals ◦ Calcaneus (Os Calcis or Heel) ◦ Talus (Astragalus) ◦ Navicular (Scaphoid) ◦ Cuboid ◦ Medial Cuneiform (1st Cuneiform) ◦ Intermediate Cuneiform (2nd Cuneiform) ◦ Lateral Cuneiform (3rd Cuneiform)   Largest, strongest bone in the foot Contains 3 articular facets or surfaces that join with the talus    “Cuneiform” literally means “wedgeshaped” Medial cuneiform is the largest Intermediate is the smallest  Talus (Astragalus) ◦ 2nd largest tarsal and most superior tarsal ◦ Located between lower leg and calcaneus  Navicular (Scaphoid)  Cuboid ◦ Lies on medial side of foot between talus and the 3 cuneiforms ◦ Lies on lateral side of foot, distal to Calcaneus and proximal to the 4th and 5th Metatarsals      Located on the plantar surface by the head of the 1st metatarsal Usually there are 2 sesamoid bones Seen mostly in adults Detached from the foot and embedded within two tendons Common site of fracture      Formed by the tibia, fibula, & talus Synovial, hinge joint Lateral Malleolus: located on fibula Medial Malleolus: located on tibia a.k.a. Ankle Mortise ◦ Deep socket formed by the tibia and fibula into which the talus fits Presentation of radiographs, pertinent anatomy, and positioning criteria.    SID is at 40-inches table top 10 x 12 IRs used for all views Full lead apron and thyroid shield should be used ◦ If you can shield it, you SHOULD shield it!  No breathing instructions required      Patient supine or seated Bend pt.’s knee and place foot flat on IR 1st digit – CR  to IP joint 2nd-5th digits – CR  to PIP joint Optional method: Angle CR 15 cephalic ◦ Opens up the joint spaces  Collimate 1-inch on all sides including 1-inch proximal to MTP joint Some protocols may require an AP of the entire foot Structures Seen  No rotation of phalanges  Open IP and MTP joint spaces  Distal ends of metatarsals  Soft tissue and bony trabeculation      Digits 1-2: Rotate foot medially 30 Digits 3-5: Rotate foot laterally 30 1st digit: CR  to IP joint 2nd – 5th digits: CR  to PIP joint Collimate 1-inch on all sides including 1inch proximal to MTP joint Shows medial rotation Structures Seen    Open IP and MTP joint spaces  1st MTP joint not always opened Distal ends of metatarsals Soft tissue and bony trabeculation       Lateromedial: digits 1-2 Mediolateral: digits 3-5 1st digit – CR  to IP joint 2nd – 5th digits – CR  to PIP joint Use tape to pull back unaffected toes Collimate 1-inch on all sides including 1-inch proximal to MTP joint Structures Seen  Phalanges in profile  Open IP joint spaces   MTP joints are overlapped and may be seen Soft tissue and bony trabeculation    Patient supine or seated Bend pt.’s knee and place foot flat on IR CR 0 or 10 cephalic ◦ Angling opens up tarsal articulations   CR enters at base of 3rd metatarsal Use of wedge filter will improve image quality      Patient standing Place IR on floor and have patient stand on IR Opposite foot should be placed back Angle CR 10-15 CR to base of 3rd metatarsal Structures Seen  No rotation of the foot  Overlap of 2nd-5th metatarsal bases   Open joint space between the medial and intermediate cuneiforms All tarsals distal to the talus, metatarsals, and phalanges   Rotate foot medially 30 CR  to base of 3rd metatarsal NOTE: A 30 lateral oblique may be used to demonstrate the 1st and 2nd metatarsal bases  Structures Seen 3rd-5th metatarsal bases free of superimposition  Sinus tarsi best seen   Best view to see the tuberosity of 5th metatarsal  5th metatarsal fx. Soft tissue and bony trabeculation   Roll pt. up onto hip of affected side Flex knee and place foot parallel to the IR ◦ Plantar surface  to IR   Dorsiflex the foot CR  to the level of the base of 3rd metatarsal      Patient standing Place IR in groove on platform Plantar surface  to IR Dosiflex foot 90 CR  to the level of the base of 3rd metatarsal Structures Seen     Metatarsals nearly superimposed Fibula overlapping posterior portion of tibia Tibiotalar joint Demonstrates anterior/posterior displacement of fx’s and foreign body   Pt. in prone position Rest the great toe on the table in a position of dorsiflexion ◦ Ball of foot should be  to the horizontal plane of the IR  CR:  and tangential to the 1st MTP joint   Pt. seated on table Adjust plantar surface of foot 75 with the plane of the IR ◦ Medial border of foot should be vertical   Pt. holds toes in flexed position with a strip of gauze CR:  to head of the 1st metatarsal bone Lewis Method Holly Method Sesamoids free of any portion of the 1st metatarsal     Patient supine or seated with leg fully extended Use sheet, gauze, or tourniquet to assist pt. into extreme dorsiflexion Angle CR 40 cephalic CR enters at the base of the 3rd metatarsal Structures Seen    Calcaneus and subtalar joint No rotation of the calcaneus Anterior portion of the calcaneus without excessive density over the posterior portion     Patient prone with ankle elevated on sandbags Dorsiflex ankle to place long axis of foot  to the tabletop Angle CR 40 caudal CR enters dorsal surface of the ankle joint Structures Seen  Calcaneus and subtalar joint  Sustentaculum tali  No rotation of the calcaneus  Anterior portion of the calcaneus without excessive density over the posterior portion     Roll pt up onto hip of affected side Plantar surface of foot parallel to the IR Dorsiflex the foot CR enters 1-inch distal to medial malleolus (at subtalar joint) Structures Seen    No rotation of calcaneus Sustentaculum tali, sinus tarsi, and lateral tuberosity seen Ankle joint and adjacent tarsals     Patient is supine or sitting Dorsiflex foot CR enters at ankle joint between malleoli Include distal tib/fib     Patient standing Place IR in groove on platform Heel pushed back against IR, toes pointing straight forward CR enters at ankle joint between malleoli Structures Seen    Tibiotalar joint space Talus slightly overlapping distal fibula Distal end of the tib/fib and proximal portion of talus      Internally rotate leg 15-20 Intermalleolar plane is parallel with the IR Dorsiflex foot CR enters midankle, between malleoli Include distal tib/fib      Patient standing Place IR in groove on platform Internally rotate leg 15-20 Dorsiflex foot CR  at anterior surface, mid-ankle, between malleoli Structures Seen  Three sides of mortise joint  Talofibular joint space in profile  No overlap of anterior tubercle of tibia with the fibula     Internally rotate leg 45 Dorsiflex foot CR enters midankle, between malleoli Include distal tib/fib Structures Seen   Tibiofibular joint Distal tib/fib overlapping some of the talus     Externally rotate leg 45 Dorsiflex foot CR enters midankle, between malleoli Include distal tib/fib      Patient standing Place IR in groove on platform Externally rotate leg 45 Dorsiflex foot CR  at anterior surface, mid-ankle, between malleoli Structures Seen  Calcaneal sulcus (superior portion of calcaneus)  Subtalar joint  Useful in locating fx’s     Roll pt up onto hip of affected side Flex knee and place foot parallel to the IR Dorsiflex the foot CR enters at the medial malleolus      Patient standing Place IR in groove on platform Lateral surface of foot in contact with IR Dorsiflex foot CR  to medial malleolus Structures Seen   Tibiotalar joint Fibula over the posterior half of the tibia      Roll pt away from affected side Medial surface of ankle in contact with the IR Dorsiflex the foot CR enters ½ inch superior to lateral malleolus This view allows the ankle to be viewed more easily in a true lateral position   Obtained after an inversion/eversion injury Done to verify the presence of a ligamentous tear ◦ Rupture of ligament would show a widening of the joint space on the side of the injury when the foot is forcibly turned toward the opposite side  Views include AP Neutral, AP Eversion Stress, & AP Inversion Stress AP Neutral AP Eversion AP Inversion Change in joint and rupture of lateral ligament (arrow) are seen What would you do? Choice A Choice B The foot has been overrotated medially The foot has been underrotated medially Choice A Choice B Re-center at the base of the 3rd proximal phalanx Angle the tube 10-15 degrees cephalic Situation A patient comes into the outpatient imaging center for a follow-up x-ray of her right foot. She has previously sustained an avulsion fracture of the tuberosity of the 5th metatarsal. Which routine view would best reveal her type of fracture? Correct Answer: Situation How many degrees has the patient’s ankle been obliqued in this image? See course schedule for reading assignment  Study Positioning Notes!!!  Worksheet  ◦ Section 1: Exercise 1, 2, 3, 16, 17 (Q.1-18) ◦ Section 2: Exercise 1, 2, 3, 4