Perthes Disease – Board-Style Questions

What this deck covers

Perthes disease in 18 board-style clinical cases with worked explanations. Each case gives you a clinical vignette, four options, the correct answer, and an explanation of why each of the other three is wrong, with the guideline or textbook it follows named on the answer.

Board-style teaching questions for paediatricians and trainees preparing for paediatric board, MRCPCH and licensing examinations. Written from published guidelines and standard paediatric textbooks, with the source named on every answer.

The 18 cases, in order

1. Who gets it
2. What the hip will not do
3. A thin dark line
4. The early picture
5. Two hips at once
6. How big is he
7. One more test
8. The dangerous phase
9. Opening out is blocked
10. The aim of treatment
11. The first few weeks
12. An operation on the bone
13. What he may do
14. Predicting the result
15. Age when it starts
16. Watching it over time
17. The other side
18. Life as a grown-up

Diagnoses and management options tested

Across the 18 cases you are asked to choose between options such as: An infant under one year, in whom it is commonest of all age groups, Loss of rolling the leg inwards and of spreading it outwards, A wide joint space with the head pushed sideways out of the socket, The socket is deepened, with the head buried inside it, Both hips at the same stage, which points to a skeletal dysplasia, Tall stature with a bone age well ahead of his real age, A urine culture, since infection explains the systemic features, The final stage, several years after the head has stopped changing its shape, The head no longer turns in but levers on the rim of the socket, Restoring the blood supply directly by an operation on the vessels, Full weight bearing and an early return to sport, Lengthening of the femur to restore the difference in leg length, Swimming and cycling, which keep the hip moving without pounding it, The number of weeks the child limped before he was first seen.

Clinical pearls from this deck

• Perthes: a boy of four to eight years, most often.
• Perthes: rotation in and opening out are lost first.
• The crescent is a fracture under the joint surface.
• Early Perthes: a smaller, whiter head on that side.
• Both heads at one stage: look for a bone dysplasia.
• Perthes children run short with a delayed bone age.

Work through the deck once for recognition, then again a week later to test yourself — each question gives the answer and explains why every other option fails.

More from this system: all MSK and orthopaedics case decks · pediatric reference values.