Focused examination for adult acquired flatfoot deformity (AAFD) including posterior tibial tendon assessment, flexibility testing, and staging of deformity.
Adult flatfoot examination requires systematic assessment of the posterior tibial tendon, hindfoot alignment, and flexibility of the deformity. Examiners expect you to perform the single heel raise test, too-many-toes sign, and differentiate flexible from rigid flatfoot.
High-Yield Exam Summary
Anatomy:
Pathophysiology Sequence:
Risk Factors:
Understanding PTT Failure: When PTT fails:
This explains all the clinical findings!
From Behind:
From Medial Side:
From Front:
From Lateral Side:
Detect forefoot abduction
More than 2 toes visible lateral to heel (normally 1-2)
Forefoot abduction - transverse tarsal joint incompetence due to PTT failure
Ability to detect true positives
Ability to exclude false positives
Course of PTT:
Palpation Findings:
Compare with Normal Side:
PTT function and hindfoot flexibility
Inability to perform heel raise, pain, or failure of heel to invert
PTT dysfunction - normally heel should invert with heel raise
Ability to detect true positives
Ability to exclude false positives
Interpreting Single Heel Raise:
The heel MUST be observed from behind - inversion is the key finding!
Assess flexibility of flatfoot
Medial arch reconstitutes (rises) with great toe dorsiflexion
FLEXIBLE flatfoot (windlass mechanism intact). If arch doesn't rise, suggests rigid flatfoot
Ability to detect true positives
Ability to exclude false positives
Direct PTT power assessment
Weakness of inversion compared to normal side
PTT weakness or rupture
Ability to detect true positives
Ability to exclude false positives
Differentiate gastrocnemius from Achilles tightness
Dorsiflexion improves with knee flexion (greater than 10° difference)
Isolated gastrocnemius tightness (amenable to gastrocnemius recession)
Ability to detect true positives
Ability to exclude false positives
Flexible Flatfoot:
Rigid Flatfoot:
Assessment Technique:
| stage | ptt | deformity | flexibility | treatment |
|---|---|---|---|---|
| Stage I | Tenosynovitis, intact | None | N/A | NSAIDs, immobilization, orthotics |
| Stage II (A) | Elongated/dysfunctional | Mild hindfoot valgus | Flexible | Orthotics +/- FDL transfer, calcaneal osteotomy |
| Stage II (B) | Elongated/dysfunctional | Greater than 30% talar uncoverage | Flexible | FDL transfer, calcaneal osteotomy, +/- lateral column lengthening |
| Stage III | Dysfunctional/ruptured | Fixed hindfoot valgus | Rigid | Triple arthrodesis or subtalar fusion |
| Stage IV | Dysfunctional | Ankle valgus added | Rigid | Pan-talar fusion or tibiotalocalcaneal fusion |
Staging Determines Surgery:
Flexibility testing is therefore CRITICAL for surgical planning!
Ankle:
Forefoot:
Neurovascular:
Contralateral Side:
| condition | age | onset | ptt | features |
|---|---|---|---|---|
| Adult Acquired (PTTD) | Middle-aged+ | Gradual | Dysfunctional | Unilateral initially |
| Flexible Pediatric | Child/adolescent | Since walking | Normal | Arch with tiptoe, often asymptomatic |
| Tarsal Coalition | Adolescent | Gradual | Normal | Rigid, painful, limited subtalar motion |
| Inflammatory (RA) | Variable | Gradual | May be involved | Bilateral, other joints affected |
| Charcot Foot | Diabetic | Acute/subacute | Variable | Neuropathic, swollen, warm |
| Congenital Vertical Talus | Birth | Congenital | N/A | Rigid rocker-bottom |
"52-year-old obese woman with progressive medial foot and ankle pain over 2 years, now difficulty walking."
High-Yield Exam Summary