TOACS FCPS Station · X‑ray Long Bones: Congenital Syphilis

📷 X‑ray Long Bones (AP view)

X-ray long bones showing osteochondritis, periostitis, and metaphyseal changes in congenital syphilis

Figure 1 · AP long bone radiograph · Congenital Syphilis

🔍 Key radiographic features:

✓ Osteochondritis – metaphyseal lucent bands (most common)
✓ Periostitis – lamellated periosteal new bone formation
✓ Wimberger sign – bilateral symmetric metaphyseal destruction (medial proximal tibia)
✓ Widened growth plate – irregular metaphyses with fraying
✓ Pathologic fractures – may be present in severe cases

📋 Clinical scenario (examiner prompt)

A 2‑month‑old infant presents with persistent rhinitis (“snuffles”), desquamating rash on the palms and soles, and hepatosplenomegaly. The mother had a reactive RPR at delivery. A long bone X‑ray (AP view) is shown.

Snuffles Metaphyseal lucent bands Rash Hepatosplenomegaly

🧑‍⚕️ Examiner tasks · TOACS

1. Identify the diagnosis from the X‑ray and clinical context.

2. Describe the X‑ray findings (osteochondritis, periostitis, Wimberger sign).

3. Explain the pathophysiology (transplacental Treponema pallidum infection).

4. Discuss evaluation and management (workup, IV penicillin G).

⚠️ Key concept: Congenital syphilis results from transplacental transmission of Treponema pallidum. Osteochondritis (metaphyseal lucent bands) is the most common skeletal finding in early congenital syphilis. Wimberger sign – bilateral symmetric destruction of the medial proximal tibia – is a pathognomonic finding.

🎯 Expected answers (for examiners)

• Diagnosis: Congenital syphilis (early, symptomatic)
• X‑ray findings: Metaphyseal lucent bands (osteochondritis), periostitis, Wimberger sign (medial tibial metaphyseal destruction)
• Pathophysiology: Transplacental transmission → treponemal invasion of bone → osteitis, periostitis
• Management: Full evaluation (CBC, LFTs, CSF, long bone X‑rays); treat with aqueous penicillin G IV ×10 days

⚡ Quick FCPS‑style MCQ

The pathognomonic radiographic finding of bilateral symmetric medial tibial metaphyseal destruction in congenital syphilis is called:

A. Wimberger sign B. Frankel line C. Trummerfeld zone D. Pelkan spur

📌 Topic summary ·

Osteochondritis
Metaphyseal lucent bands

Periostitis
Lamellated new bone

Wimberger sign
Medial tibial metaphyseal destruction

Early CS
Snuffles, rash, hepatosplenomegaly

Late CS
Hutchinson teeth, interstitial keratitis

Treatment
Aqueous penicillin G IV ×10 days

Feature	Congenital Syphilis
Transmission	Transplacental (any stage of maternal syphilis)
Early (<2y)	Snuffles, rash, osteochondritis, hepatosplenomegaly
Late (>2y)	Hutchinson teeth, interstitial keratitis, saber shins
X‑ray	Metaphyseal lucent bands, periostitis, Wimberger sign
Treatment	Aqueous penicillin G IV ×10 days

🩻 TOACS FCPS Station · X‑ray Long Bones: Congenital Syphilis

📷 X‑ray Long Bones (AP view)

🧑‍⚕️ Examiner tasks · TOACS

📌 Topic summary ·