- Talocalcaneal coalition
- Calcaneonavicular coalition
- Peroneal spastic flatfoot
- This page refers to abnormal connections of the tarsal bones, commonly referred to as 'tarsal coalition'
- First described by Buffon in 1750 or 1769 (need citation)
- In 1948, Harris and Beath were the first to identify tarsal coalition as a cause of painful and rigid pes planovalgus
- Definition: abnormal osseous, cartilaginous or fibrous connection between two or more tarsal bones
- Due to a failure of differentiation and segmentation of primitive mesenchyme into the distinct tarsal bones
- The coalition can be bony (synostosis), cartilaginous (synchondrosis), or fibrous (syndesmosis)
- May involve fusion of the accessory ossicles
- It is an often unrecognised cause of foot and ankle pain
- Natural history
- Majority are cartilaginous at birth and are therefore asymptomatic
- Evidence suggests coalitions remain asymptomatic into adulthood
- When symptoms arise, thought to be a result of microfractures of the coalition and inflammation of the surrounding soft tissue from repetitive overload
- Age of presentation varies, depending on which bones are involved
- Appears to be approximately 3--4 years after ossification of the coalition
- Talocalcaneal and calcaneonavicular coalitions are its most common subtypes, represent about 90% of junctions
- Other investigators have reported a nearly equal prevalence of talocalcaneal and calcaneonavicular coalitions
- More readily diagnosed with conventional radiography, which may contribute to their reported higher prevalence
- Thought to be due to a failure of segmentation of primitive mesenchyme during development
- May occur due to may occur because of degenerative joint diseases
- Examples: inflammatory arthritis, fibular hemimelia, congenital talipes equinovarus, Apert syndrome, arthrogryposis, and Nievergelt--Pearlman syndrome
- Pes Planus
- Other congenital malformations
- Including carpal fusions, carpal synostosis with radial head subluxation, symphalangism, and partial adactyly
- Ankle Sprain
- Tarsal Bones
- Fractures & Osseous Disease
- Traumatic/ Acute
- Stress Fractures
- Other Osseous
- Dislocations & Subluxations
- Muscle and Tendon Injuries
- Ligament Injuries
- Symptoms initiate with the onset of ossification, calcaneonavicular (8-12 years), talocalcaneal (8-12 years), talonavicular (3-5 years)
- Mid-, hindfoot or tarsal pain, sometimes diffuse
- Trouble walking on uneven surfaces
- If there is a precipitating event, trauma, weight gain, or an increase in athletic activity
- Pain is diffuse, exacerbates during physical activity, and may be triggered by minimal trauma
- Progressing to decreased range of motion, especially inversion/eversion of the subtalar joint
- Rigid deformity is usually the end point
- Physical Exam: Physical Exam Foot
- Rigid pes planus, hindfoot valgus
- Inability to roll onto lateral side of foot (secondary to rigid pes planus)
- Tightness of peroneal muscles, long extensors which may be obvious dorsally
- "Double medial malleolus" with talocalcaneal coalition
- Ankle range of motion is normal while subtalar range of motion is restricted
- Special Tests
- Standard Radiographs Foot, Standard Radiographs Ankle
- Initial imaging modality of choice
- Views should include anteroposterior, lateral, oblique, and axial weight-bearing
- Harris axial view (Harris-Beath)
- Sometimes termed Harris projection or penetrated axial projection
- Special radiographic view that is used for assessment of talocalcaneal coalition
- X-ray beam is angled between 35 and 45 degrees
- Calcaneonavicular coalitions
- Talocalcaneal coalitions
- 'C' sign
- Absent middle facet may be a more accurate radiographic finding
- Dorsolateral talar beak
- Thought to occur due to impaired subtalar joint motion, subsequently the navicular overrides the talus.
- Periosteal elevation occurs at the insertion of the talonavicular ligament, a cycle of osseous leads to formation
- Alternatively, may occur due to peroneal spasm with repetitive dorsolateral overload, compression of the talar head
- Note: may occur absent a tarsal coalition
- More sensitive, more specific than xray
- Also assesses for soft tissue injuries, bone edema
- Similar utility for osseous connections, but less for fibrous
- offers a more precise evaluation of the site and size of coalition
- Help determine determine surgical approach, i.e. resection, arthrodesis
- Can exclude multiple coalitions and readily depicts associated degenerative changes
- Considers joint involvement, arthrosis extension to help in recommending surgical therapy
- Type IA: extra-articular coalition without secondary arthritis
- Type IB: intra-articular coalition with secondary arthritis
- Type IIA: extra-articular coalition without secondary arthritis
- Type IIB: intra-articular coalition with secondary arthritis
- Based on three-dimensional reconstructed computed tomography images
- Type I: linear coalitions (41%)
- Type II: linear coalitions with posterior hook (17%)
- Type III: shingled coalitions (15%)
- Type IV: complete osseous coalitions (11%)
- Type V: posterior coalitions (17%)
- Asymptomatic or incidentally discovered lesions
- Most symptomatic lesions upon initial presentation
- Initial therapy
- Shoe inserts
- Activity modification
- If symptoms persist, consider
- Custom orthotics
- Cast immobilization
- Failure of conservative management
- Achieve painless functional hindfoot movement without deformity
- Subtalar or triple arthrodesis
- Excision of coalition with or without interposition of fat or tendon
Rehab and Return to Play
- Needs to be updated
Return to Play/ Work
- Needs to be updated
Complications and Prognosis
- Incidental or asymptomatic lesions
- No evidence suggesting that asymptomatic coalition may lead to future problems
- Conservative vs surgical management
- Calcaneonavicular coalitions respond less to conservative treatment than talocalcaneal coalitions
- Surgical outcomes
- Mahan et al observed 73% of patients achieved good results, regardless of the type of coalition
- Khoshbin et al reevaluated patients after resection of calcaneonavicular and talocalcaneal coalitions, found that 85% of the patients did not require additional procedures
- Mosca showed 87% of patients achieved good results after talocalcaneal coalition resection
- Predictors of good outcome with conservative management (need citation)
- Skeletal immaturity at presentation
- Nonathletic patient
- Ankylosed subtalar joint in neutral
- Pes Planus
- Chronic pain
- Inability to return to sport
- Surgical complications
- Incomplete resection
- Superficial Peroneal Nerve Injury
- Sports Medicine Review Foot Pain: https://www.sportsmedreview.com/by-joint/foot/
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