Sirry A. The pseudocystic triangle in the normal os calcis. Acta Radiol 1951; 36: 515

Described a triangular, relatively translucent area (in the calcaneus) with the apex directed towards the superior surface of the bone with the base resting on its inferior surface.

In the more striking cases it may resemble a bone and thus cause an error in diagnosis Triangular lucency did not show well 70%

Sirry: The pseudocystic triangle in the normal os calcis Acta Radiol 1951; 36: 515 Moderately well 22% Strikingly well 7% Strikingly well 7% 9 yo boy twisted his ankle Dx: “Could very well be a pseudocyst” Suggested a tangential view Keats TE, Harrison RB. The calcaneal nutrient foramen: A useful sign in the differentiation of true from simulated . Skel Radiol (1979) 3:239-40

Visualization of the nutrient foramen is a useful sign in differentiation of this entity from a true cyst.

Review of our cases of true calcaneal cysts …indicated that the nutrient foramen is not seen. Nutrient foramina Hall FM. The calcaneal nutrient foramen. Skel Radiol 1980; 5:135-6.

Authors provide no references or anatomic data…no supportive data or proof of these diagnoses. Why couldn’t a nutrient foramen be present on either side of a more centrally located cyst? Dr Keats’ response was that it was “theoretically possible, but has not occurred in our experience.” The real point is that the foramen could be useful in decision making for the radiologist. How often is a nutrient foramen present on a lateral radiograph of the foot or ankle? How often is a nutrient foramen present on a lateral radiograph of the foot or ankle?

On review of 165 cases 15% 11 yo boy with bilateral heel pain Dx: “Pseudocyst. Tangential will confirm” Hx: 13 yo boy with “heel lesion” Dx: Cyst or lipoma 16 yo boy with hx of “lesion of calcaneus” Dx: Unicameral bone cyst 9 yr 5 yr

9 yo boy with toe Dx: Bone cyst 11 yo girl with ankle injury Dx: Consistent with a bone cyst 12 yo girl with ankle pain Dx: Bone cyst 16 yo boy with ankle injury Dx: Pseudocyst, cyst or lipoma 7 yo boy with hx “bone cyst” Dx: Bone cyst or lipoma 13 yo boy with hx trauma to distal fibula Dx: Bone cyst

Conclusion re cysts in the calcaneus • Always look in the anterior aspect of the calcaneus for cysts Conclusion re cysts in the calcaneus • Always look in the anterior aspect of the calcaneus for cysts • Do not call all of these lesions “pseudocysts” Conclusion re cysts in the calcaneus • Always look in the anterior aspect of the calcaneus for cysts • Do not call all of these lesions “pseudocysts” • Nutrient foramina have nothing to do with bone cysts Conclusion re cysts in the calcaneus • Always look in the anterior aspect of the calcaneus for cysts • Do not call all of these lesions “pseudocysts” • Nutrient foramina have nothing to do with bone cysts • Lipomas are not in the differential Conclusion re cysts in the calcaneus • Always look in the anterior aspect of the calcaneus for cysts • Do not call all of these lesions “pseudocysts” • Nutrient foramina have nothing to do with bone cysts • Lipomas are not in the differential • Most calcaneal bone cysts are incidental 38 Calcaneal bone tumors from the Scottish Registry 2012

24 benign Unicameral bone cysts 6 Chondroblastoma 3 PVNS with calc erosion 3 Other 12

13 malignant Osteosarcoma 6 Chondrosarcoma 5 Ewing 2

JBJS Br 2012 vol 94-B no. SUPP XXVIII 26 OSTEOCHONDRAL LESION TALUS

• Trauma (inversion ) + hx > 85%. • Bilat 10-25%. X-ray both ankles? • Rx: Conservative mgt successful 50% OSTEOCHONDRAL LESION TALUS

Medial Central Lateral

Deeper Superficial Less sx More sx 14 yo boy with pain for 4 mo after long day of walking

16 yo girl with hx of bilateral ankle inversions

4-8-10 5-15-11 6 yo girl with multiple ankle sprains 7-28-11

3-29-11 13 yo boy ankle pain for months 7-28-11 7-28-11

Failed to follow-up 4-30-2010 4-13-2011 9 yo boy 4-13-2011 6-16-11 13 yo boy with ankle pain x 3 years

6-27-2011

13 yo girl twisted ankle 4 mo prior

12 yo boy with bilat ankle pain x 4 mo L>R

13 yo girl with bilateral ankle pain for 3 mo Did not keep follow-up appointments 17 yo with ESRD Incidental finding on renal osteodystrophy surveys

Tarsal Coalitions Tarsal Coalitions

Calcaneonavicular Talocalcaneal (Subtalar) Tarsal Coalitions

Things they have in common Tarsal Coalitions

Things they have in common

1. Foot pain 2. Pes planus 3. Inflexible foot/ankle on physical 4. Biomechanical issues resulting in talar beaks 5. Often overlooked on foot/ankle XR’s Tarsal Coalitions

Things they have in common

Most are fibrous or cartilaginous Calcaneonavicular Coalition Calcaneonavicular Coalition

Reasons for missing the diagnosis

1. We don’t look for it 2. We dismiss subtle changes as being normal 3. We overlook the signs on the lateral view Calcaneonavicular Coalition Best views for diagnosis

1. Oblique view of foot 2. Lateral view of foot or ankle Calcaneonavicular Coalition

What are the signs?

Oblique view Narrowing C-N joint Squared off ant process Tapered navicular Calcaneonavicular Coalition

What are the signs?

Oblique view Irregularity of joint margins Sclerosis Calcaneonavicular Coalition

What are the signs?

Oblique view Synostosis Calcaneonavicular Coalition

What are the signs?

Lateral view Anteater nose Talar beak Calcaneonavicular Coalition

Anteater nose J Pediatr Orthop. 1987 Nov-Dec;7(6):709-11.

The "anteater nose": a direct sign of calcaneonavicular coalition on the lateral radiograph. Oestreich AE, Mize WA, Crawford AH, Morgan RC Jr. Department of Pediatric Radiology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-2899

Abstract On the lateral foot or ankle film of patients at least 9 years old with calcaneonavicular bar (CNB), there is a tubular prolongation anteriorly of the superior calcaneus which fancifully resembles the nose of an anteater. This prolongation approaches or overlaps the midportion of the navicular. Such a configuration was present in all 30 feet reviewed with CNB, but not in 125 feet of 100 subjects, in their second decade, without CNB Talar ridge

Talar beak

Calcaneonavicular Coalition Subtalar Coalition Subtalar Coalition Reasons for missing the diagnosis

1. We don’t look for it 2. Overlap between coalition and normal Subtalar Coalition Best views for diagnosis

1. Lateral view of foot or ankle 2. Tangential view of calcaneus

Pseudo-anteater nose

Subtalar Coalition

What are the signs? Subtalar Coalition

What are the signs?

1. C sign Subtalar Coalition

What are the signs?

1. C sign 2. Talar beak Problem with the C sign?

Normal Subtalar coalition 4+ C Sign

2+ C Sign

Talar Coalitions

1

3

2

2 year follow-up

Elbow Fractures and Dislocations Confusing displaced fractures with dislocations 7 yo boy who fell from monkey bars 4 yo girl who fell from a bed

2 yo girl who tripped and landed on her side Displaced fractures + dislocations 7 yo boy who fell from scooter going downhill

14 yo girl fell from a 4 wheeler Supracondylar process

6 yo girl tripped and fell while running 15 yo boy fell from bicycle

4 yo boy with lat condyle fracture 7 yo boy hx unknown

10 yo boy fell from trampoline 8 yo girl