Tarsal coalition radiology description

1. TARSAL COALITION
By: DR ANIL KUMAR P
Junior resident
dept of Orthopaedics
R L J H and R C, kolar

2. • Def :Tarsal Coalition is a common congenital condition caused
by failure of embryonic segmentation leading to abnormal
coalition 2 or more of the tarsal bones.
• The condition is usually asymptomatic, but may present with a
flatfoot deformity or recurrent ankle sprains.

4. • Prevalance :varies from 1%-2%
• Age of onset:
• Calcaneonavicular usually 8-12 years old
• Talocalcaneal usually 12-15 years old
• Anatomic location
• Calcaneonavicular (most common)
• Talocalcaneus

5. TYPES
• Congenital : most common
• Acquired
1. less common and caused by trauma
2. degenerative
3. infections

6. EMBRYOLOGY
• Failure of mesenchymal segmentation leading to coalition
between two or three tarsal bones
• Develops into a fibrous coalition, or undergoes metaplasia to
cartilage which can later become bone

7. PATHOANATOMY
GAIT MECHANICS
• Subtalar joint will normally rotate 10 degrees internally during stance
phase
• In presence of coalition, internal rotation does not occur
DEFORMITY
• Flattening Of Longitudinal Arch
• Abduction Of Forefoot
• Valgus Hindfoot
• Peroneal Spasticity (also known as peroneal spastic flatfoot)

8. PAIN GENERATOR THEORIES
• Ossification of previously fibrous or cartilaginous coalition
• Microfracture at coalition bone interface
• Secondary chondral damage or degenerative changes
• Increased stress on other hindfoot joints

9. ASSOCIATED CONDITIONS
• Nonsyndromic : autosomal dominant
• Syndromic
1. fibular hemimelia
2. carpal coalition
3. FGFR-associated craniosynostosis (FGFR-1, FGFR-2, FGFR-
3)
4. Apert syndrome, Pfeiffer, Crouzon, Jackson-Weiss and
Muenke

10. CLASSIFICATION
• ANATOMIC CLASSIFICATION
1. Calcaneonavicular
2. Between calcaneus and navicular bones (most common)
3. Talocalcaneal
4. Middle facet of talocalcaneal joint
• PATHOANATOMIC CLASSIFICATION
1. Fibrous coalition (syndesmosis)
2. Cartilagenous coalition (synchondrosis)
3. Osseous coalition (synostosis)

12. Symptoms
• History of prior recurrent ankle sprains
• Asymptomatic
• Pain
• Pain worsened by activity
• Calf pain

13. Physical exam
• Hindfoot valgus
• Forefoot abduction
• Pes planus
• Limited subtalar motion
• Heel cord contractures
• Tests:reverse Coleman block test

14. IMAGING
RADIOGRAPHS
• Anteroposterior view
• Standing lateral foot view
• 45-degree internal oblique view
(most useful for calcaneonavicular coalition)
• Harris view of heel

15. NORMAL XRAYS

17. CALCANEONAVICULAR COALITION

18. TALOCALCANEAL COALITION

21. Harris view of heel- access varus or valgus
and displacement and angulation

22. Multiple coalitions

23. CT
• Cross-sectional imaging (CT or MRI) is often needed in case of
talocalcaneal coalition due to lower sensitivity of conventional
radiography in its detection.
• CT depicts precisely the extent of coalition and is therefore
useful in resection planning or determining the indications for
arthrodesis.

25. TALOCALCANEAL COALITION

27. CUBONAVICULAR

30. MRI
• May help distinguish between:
• Osseous Coalition
• Continuity Of Marrow Signal
• Fibrous Coalition
• Low Signal On T1/T2 Weighted Sequences
• Cartilaginous Coalition
• Intermediate T2/Stir +/- Fluid Signal
• Possible associated findings include marrow or soft tissue
edema

31. TALOCALCANEAL

33. CALACNEONAVICULAR

35. General features of the non-osseous
coalition
• Subchondral reactive bony
changes
• Adjacent marrow edema (MR)
• Unusual articular orientation
• Joint space loss

37. THANK YOU