Extremity Anomalies

Question 1

Ludloff’s Spot/Fleck

Answer 1

Normal lucency visualized in the intracondylar groove of the knee
Typically seen on a lateral knee view

Question 2

Os Acetabuli

Answer 2

Accessory ossicle lateral to the acetabulum

DDX: calcific tendonitis

Question 3

Pitt’s Pit

Answer 3

Lucency visualized along the anterior aspect of the femoral neck
Average size: 5mm

Question 4

Femoral Acetabular Impingement

Answer 4

Pincer Type: bony extension of acetabular bone
Cam Type: cortical protrusion on the femoral head laterally
Clinical: hip/groin pain

Question 5

Developmental Dysplasia of Hip

Answer 5

Putti’s Triad:
Shallow Acetabulum
Superolateral femur displacement
Delayed ossification

Question 6

Slipped Capital Femoral Epiphysis

Answer 6

Best visualized in Frog leg view
Klein's line does not intersect femoral epiphysis
Clinical:
Limited ROM
Hip tenderness
Painful internal rotation and abduction
Common in 10-15 Y males
Refer to Ortho

Question 7

Bipartite Patella

Answer 7

displaced superolateral quadrant of patella. Tripartite and multipartite also possible

Question 8

Dorsal Defect of Patella

Answer 8

circular lucency in superolateral quadrant of patella.

Average size: 9mm

Question 9

Os Fabella

Answer 9

Accessory sesmoid posterior to the lateral femoral condyle (within lateral head of gastroc muscle)

Question 10

Tug Lesion

Answer 10

Cortical thickening along soleal line and fibula

common in active kids

Question 11

Tarsal Coalition

Answer 11

Congenital fusion of 2 or more tarsal bones. Appears clinically as rigid flat foot.

Calcaneonavicular: Ant eater nose sign - square protrusion from calcaneus on the medial oblique view

Talocalcaneal: C sign and Talar beak on the lateral ankle view

Question 12

Talar Beak

Answer 12

Osseous growth on the superior surface of the talus

Question 13

Os Subfibulare

Answer 13

Ossicle inferior to the lateral malleolus

Question 14

Accessory Navicular

Answer 14

Ossicle medial and posterior to the navicular.

Type I (Os Tibiale Externum) - small ossicle in the posterior tibial tendon

Type II (Prehallux) - large triangular ossicle

Type III (Cornuate Navicular) - complete fusion with navicular

Question 15

Os Trigonum

Answer 15

Accessory ossicle posterior to the ankle

Question 16

Os intermetatarseum

Answer 16

Accessory ossicle between the 1st and 2nd metatarsal

Question 17

Os Peroneum

Answer 17

Accessory Ossicle in the fibularis longus tendon

DDX: unfused apophysis of the 5th metatarsal or avulsion fracture

Question 18

Humeral Notch

Answer 18

cortical notch on medial proximal metaphysis of humerus

Commonly seen bilaterally

Question 19

Rhomboid Fossa

Answer 19

Depression on the medial inferior surface of the clavicle (By CC ligaments)

Question 20

Prominent Conoid Tubercle

Answer 20

Triangular shaped osseous growth by CC ligaments

Question 21

Os Acromiale

Answer 21

Unfused apophysis of distal acromion

Diagnosed after 21-25 Y

Question 22

Supracondylar Process

Answer 22

exotosis in the anterior distal humerus

Question 23

Os Supratrchlear Dorsale

Answer 23

ossicle within the olecranon fossa

Question 24

Coronoid Bone

Answer 24

ossicle within the coronoid fossa

Question 25

Madelung Deformity

Answer 25

Dorsal medial bowing of the radius
V shape of proximal carpals
Increased interosseus space

Question 26

Negative Ulnar Variance

Answer 26

Short Ulna, ulna appears more proximal in PA wrist

Associated with ulnar impingement syndrome

Question 27

Positive Ulnar Variance

Answer 27

Long Ulna, Ulna appears more distal in PA wrist

Associated with Ulnar impaction syndrome

Question 28

Os Styloideum

Answer 28

Accessory ossicle at the base of the 2nd metacarpal

Carpal Boss: painful lump on the dorsum of the wrist

Question 29

Carpal Coalition

Answer 29

Fusion of carpal bones
Most common: Lunate and Triquetrum
2nd most common: Capitate and Hamate