A 13-year-old obese boy has pain in the left knee and thigh for 6 weeks and now limps. When the left hip is flexed, it rolls into external rotation. On the AP pelvis X-ray, a line drawn along the superior border of the left femoral neck does not cut the femoral epiphysis. What is the most likely diagnosis?

Slipped capital femoral epiphysis

Osteosarcoma of the distal femur

Stress fracture of the femoral neck

A 6-year-old boy has had a painless limp for 2 months, with occasional pain in the right knee after play. He is afebrile, and ESR is normal. Abduction and internal rotation of the right hip are limited. X-ray shows a smaller, dense right femoral epiphysis with a subchondral fracture line. What is the most likely diagnosis?

Slipped capital femoral epiphysis

A 12-year-old boy with a stable, mild slipped capital femoral epiphysis on the right is admitted from OPD. What is the most appropriate treatment?

In situ fixation with a single cannulated screw

Closed manipulation to reduce the slip, then fixation

Traction followed by non-weight bearing

Paediatric orthopaedics and bone tumours

22 NEET-PG practice questions on Paediatric orthopaedics and bone tumours, part of Orthopaedics. The first 22 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 13-year-old obese boy has pain in the left knee and thigh for 6 weeks and now limps. When the left hip is flexed, it rolls into external rotation. On the AP pelvis X-ray, a line drawn along the superior border of the left femoral neck does not cut the femoral epiphysis. What is the most likely diagnosis?
1. APerthes disease
2. BSlipped capital femoral epiphysis
3. COsteosarcoma of the distal femur
4. DStress fracture of the femoral neck
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Answer: B · Slipped capital femoral epiphysis
Slipped capital femoral epiphysis is a displacement of the femoral neck forwards and upwards relative to the epiphysis through the growth plate, typically in obese adolescent boys. Pain is often referred to the knee, and the hip turns into external rotation on flexion (Drehmann sign). Klein's line along the upper neck normally passes through part of the epiphysis; failure to do so (Trethowan sign) shows a slip. A frog-leg lateral view shows early slips best.
- A: Perthes affects younger children with a dense, fragmented head.
- C: A distal femoral tumour does not cause obligatory external rotation of the hip.
- D: A stress fracture does not displace the epiphysis on Klein's line.
Question 2 · Medium
A 32-year-old woman has a slowly growing hard swelling behind the lower end of the right thigh for 2 years. X-ray shows a dense, lobulated bony mass stuck to the posterior cortex of the distal femoral metaphysis, wrapping around the bone, with a thin lucent line between parts of the mass and the cortex. What is the most likely diagnosis?
1. AMyositis ossificans
2. BParosteal osteosarcoma
3. CConventional osteosarcoma
4. DOsteochondroma
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Answer: B · Parosteal osteosarcoma
Parosteal osteosarcoma is a low-grade surface osteosarcoma of young adults that typically arises from the posterior distal femur. It forms a dense, lobulated mass that wraps around the bone, often with a lucent cleft between tumour and cortex. It grows slowly and has a much better prognosis than conventional osteosarcoma. Wide excision is the main treatment.
- A: Myositis ossificans follows injury and matures from the edge inward.
- C: Conventional osteosarcoma affects adolescents, is aggressive and destroys the medulla.
- D: Osteochondroma has a cartilage cap and its cortex and marrow are continuous with the bone.
Question 3 · Medium
A 6-year-old boy has had a painless limp for 2 months, with occasional pain in the right knee after play. He is afebrile, and ESR is normal. Abduction and internal rotation of the right hip are limited. X-ray shows a smaller, dense right femoral epiphysis with a subchondral fracture line. What is the most likely diagnosis?
1. APerthes disease
2. BSlipped capital femoral epiphysis
3. CTransient synovitis of the hip
4. DTuberculosis of the hip
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Answer: A · Perthes disease
Legg-Calve-Perthes disease is idiopathic avascular necrosis of the femoral head in children of about 4-8 years, more often boys. It presents with a limp and pain referred to the knee, limited abduction and internal rotation, and normal inflammatory markers. X-ray shows a dense, smaller epiphysis and a subchondral fracture line (crescent sign), followed by fragmentation. The aim of treatment is to keep the head contained in the acetabulum while it heals.
- B: SCFE occurs in adolescents and the epiphysis slips rather than becoming dense.
- C: Transient synovitis lasts days with a normal X-ray.
- D: Hip TB raises the ESR and shows osteopenia with joint destruction.
Question 4 · Easy
A Class 10 student, aged 16, is brought by his father to the orthopaedic OPD for a hard, tender lump on the inner side of the lower left thigh that has kept him awake at night for 7 weeks. Radiograph of the lower femoral metaphysis shows a mixed lytic and sclerotic lesion with a 'sunray' periosteal reaction and a Codman triangle. What is the most likely diagnosis?
1. AGiant cell tumour
2. BEwing sarcoma
3. COsteosarcoma
4. DChondrosarcoma
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Answer: C · Osteosarcoma
Osteosarcoma is the commonest primary malignant bone tumour in adolescents and usually arises in the metaphysis around the knee. Tumour bone in the soft tissue gives a sunray (sunburst) appearance, and lifted periosteum forms a Codman triangle at the edge. Diagnosis is confirmed by core biopsy. The lungs are the main site of spread, so CT chest is part of staging.
- A: Giant cell tumour is lytic, epiphyseal and seen after growth plate closure.
- B: Ewing sarcoma is typically diaphyseal with onion-peel layering.
- D: Chondrosarcoma affects adults over about 40 and shows ring-and-arc calcification.
Question 5 · Medium
A 12-year-old boy with a stable, mild slipped capital femoral epiphysis on the right is admitted from OPD. What is the most appropriate treatment?
1. AClosed manipulation to reduce the slip, then fixation
2. BIn situ fixation with a single cannulated screw
3. CTraction followed by non-weight bearing
4. DHip spica for 6 weeks
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Answer: B · In situ fixation with a single cannulated screw
A stable SCFE is fixed where it lies (in situ) with a single cannulated screw across the growth plate, which stops further slipping and closes the physis. Forceful manipulation to reduce the slip is avoided because it damages the blood supply and causes avascular necrosis. The patient is kept non-weight-bearing until surgery, and the other hip is watched because bilateral slips are common.
- A: Forceful reduction risks avascular necrosis of the femoral head.
- C: Traction and rest alone do not stabilise the physis.
- D: A spica does not reliably stop the slip and has many complications.
Question 6 · Medium
A 3-month-old boy with bilateral idiopathic clubfoot has had five weekly Ponseti casts. Cavus, adductus and varus are corrected, the foot abducts well, but the ankle dorsiflexes only to 5 degrees short of neutral. What is the next best step?
1. AFoot abduction brace without tenotomy
2. BPercutaneous tenotomy of the tendo Achilles
3. CPosteromedial soft-tissue release
4. DForceful dorsiflexion in further casts
Answer and explanation in LearnFree account
Question 7 · Hard
A 9-year-old short, overweight girl has had left knee pain and a limp for 3 weeks. She is lethargic, and her school performance has fallen. Her height is below the 3rd centile and her growth has slowed. X-ray shows a slipped capital femoral epiphysis on the left. Which investigation is most important before planning further care?
1. AThyroid function tests
2. BSerum uric acid
3. CSerum vitamin B12
4. DHLA-B27 typing
Answer and explanation in LearnFree account
Question 8 · Hard
A 3-year-old girl is brought from a remote village with a waddling, limping gait on the right. Telescopy is positive on the right, and X-ray shows a high dislocation of the right femoral head with a shallow acetabulum. She has had no previous treatment. What is the most appropriate treatment?
1. AObservation and review at skeletal maturity
2. BPavlik harness worn full time for 12 weeks
3. CClosed reduction under anaesthesia and hip spica
4. DOpen reduction with femoral shortening and pelvic osteotomy
Answer and explanation in LearnFree account
Question 9 · Medium
A 14-month-old girl has just started walking with a limp. With her lying supine and both hips and knees flexed with the feet together on the couch, the left knee is lower than the right. Which sign has been demonstrated, and what does it suggest?
1. ATrendelenburg sign, left hip dislocation
2. BGaleazzi sign, right hip dislocation
3. CGaleazzi sign, left hip dislocation
4. DOrtolani sign, right hip dislocation
Answer and explanation in LearnFree account
Question 10 · Medium
A 16-year-old girl has a mass at the lower end of the femur. Core biopsy shows pleomorphic malignant spindle cells. Which histological feature is required for the diagnosis of osteosarcoma?
1. AMalignant cartilage with lacunae
2. BOsteoid formed directly by the tumour cells
3. CSheets of small round blue cells
4. DMultinucleated osteoclast-like giant cells
Answer and explanation in LearnFree account
Question 11 · Medium
A 15-year-old with a suspected malignant tumour of the distal femur is to have a biopsy. Which principle should guide the biopsy?
1. APlace the tract where it can be removed at surgery
2. BTake tissue from the reactive edge of the tumour
3. CDo an excision biopsy of the whole lesion
4. DUse a transverse incision for a better scar
Answer and explanation in LearnFree account
Question 12 · Hard
A 34-year-old woman has a large biopsy-proven giant cell tumour of the sacrum. Resection would sacrifice the sacral nerves and bladder function, so the team plans medical treatment with a drug that targets the tumour's key pathway. Which drug is used, and which check is most important during treatment?
1. AZoledronic acid; serum uric acid
2. BDenosumab; serum calcium and dental health
3. CImatinib; ECG for QT interval
4. DMethotrexate; liver and renal function
Answer and explanation in LearnFree account
Question 13 · Easy
In the Ponseti method for congenital talipes equinovarus, which deformity is corrected first?
1. AAdductus
2. BEquinus
3. CCavus
4. DVarus
Answer and explanation in LearnFree account
Question 14 · Medium
A 14-year-old boy has a confirmed high-grade osteosarcoma of the proximal tibia without metastasis. His parents are told about the treatment plan. Consider these statements: 1. Chemotherapy is given before surgery. 2. Limb-salvage surgery is possible in most patients. 3. Radiotherapy is the main local treatment. 4. The lungs are the commonest site of metastasis. Which statements are correct?
1. A2 and 3 only
2. B3 and 4 only
3. C1, 2 and 3 only
4. D1, 2 and 4 only
Answer and explanation in LearnFree account
Question 15 · Medium
A 2-month-old boy has a dislocated but reducible left hip, confirmed on ultrasound. What is the most appropriate treatment?
1. ATriple nappies and review at 6 months
2. BPavlik harness
3. COpen reduction of the hip
4. DClosed reduction and hip spica
Answer and explanation in LearnFree account
Question 16 · Medium
A 30-year-old man has a biopsy-proven giant cell tumour of the distal femur. Consider these statements: 1. It arises in the epiphysis after the growth plate closes. 2. The multinucleated giant cells are the neoplastic cells. 3. Extended curettage with an adjuvant and bone cement is the usual treatment. 4. Lung metastases can occur although the tumour is usually benign. Which statements are correct?
1. A1, 3 and 4 only
2. B2 and 3 only
3. C2 and 4 only
4. D1 and 2 only
Answer and explanation in LearnFree account
Question 17 · Medium
After clubfoot correction with Ponseti casts and tenotomy, the parents of a 4-month-old ask why their child must keep wearing the shoes-on-a-bar brace when the feet now look normal. What is the most appropriate counselling?
1. AThe brace is optional once the feet look normal
2. BPoor brace use is the main cause of relapse
3. CThe brace mainly speeds walking milestones
4. DRelapse is rare after a full set of casts
Answer and explanation in LearnFree account
Question 18 · Easy
During the newborn check of a first-born girl delivered by breech, the paediatrician flexes the hips and knees, then gently abducts the left thigh while lifting the greater trochanter forwards; a clunk is felt as the head moves. What does this test show?
1. ANormal ligamentous laxity of the newborn
2. BA reduced hip that can be dislocated
3. CFixed dislocation that cannot be reduced
4. DA dislocated hip that can be reduced
Answer and explanation in LearnFree account
Question 19 · Medium
The parents of a boy with Perthes disease ask about his prognosis. Consider these statements: 1. Onset after about 8 years of age carries a worse outlook. 2. The Herring lateral pillar classification helps predict the outcome. 3. Girls have a better outlook than boys. 4. Treatment aims to keep the femoral head contained in the acetabulum. Which statements are correct?
1. A1 and 3 only
2. B2 and 3 only
3. C1, 2 and 4 only
4. D1, 2 and 3 only
Answer and explanation in LearnFree account
Question 20 · Medium
A 6-week-old girl has asymmetric thigh folds, and on examination the left hip feels unstable. Her mother asks which test will show the problem. What is the investigation of choice at this age?
1. AMRI of both hips
2. BCT scan of the pelvis
3. CPlain X-ray of the pelvis
4. DUltrasound of the hips
Answer and explanation in LearnFree account
Question 21 · Easy
A 28-year-old woman has a painful swelling just below the left knee for 4 months. X-ray shows an eccentric, expansile lytic lesion in the epiphysis and metaphysis of the proximal tibia, reaching up to the subchondral bone, with a thin cortex, no matrix calcification and a 'soap bubble' look. What is the most likely diagnosis?
1. AGiant cell tumour
2. BAneurysmal bone cyst
3. CChondroblastoma
4. DSimple bone cyst
Answer and explanation in LearnFree account
Question 22 · Hard
A 70-year-old man who has had Paget's disease of the pelvis and right femur for 15 years develops increasing pain in the right thigh over 2 months, now present at rest and at night, with a tender swelling. His serum ALP, stable for years, has risen sharply. X-ray shows a destructive lesion in the femur with a soft-tissue mass. What is the most likely diagnosis?
1. ASecondary osteosarcoma
2. BChronic osteomyelitis of the femur
3. CPathological fracture from Paget's disease
4. DActive phase of Paget's disease
Answer and explanation in LearnFree account

Paediatric orthopaedics and bone tumours

A 12-year-old boy with a stable, mild slipped capital femoral epiphysis on the right is admitted from OPD. What is the most appropriate treatment?

A 3-month-old boy with bilateral idiopathic clubfoot has had five weekly Ponseti casts. Cavus, adductus and varus are corrected, the foot abducts well, but the ankle dorsiflexes only to 5 degrees short of neutral. What is the next best step?

A 3-year-old girl is brought from a remote village with a waddling, limping gait on the right. Telescopy is positive on the right, and X-ray shows a high dislocation of the right femoral head with a shallow acetabulum. She has had no previous treatment. What is the most appropriate treatment?

A 14-month-old girl has just started walking with a limp. With her lying supine and both hips and knees flexed with the feet together on the couch, the left knee is lower than the right. Which sign has been demonstrated, and what does it suggest?

A 16-year-old girl has a mass at the lower end of the femur. Core biopsy shows pleomorphic malignant spindle cells. Which histological feature is required for the diagnosis of osteosarcoma?

A 15-year-old with a suspected malignant tumour of the distal femur is to have a biopsy. Which principle should guide the biopsy?

In the Ponseti method for congenital talipes equinovarus, which deformity is corrected first?

A 2-month-old boy has a dislocated but reducible left hip, confirmed on ultrasound. What is the most appropriate treatment?

After clubfoot correction with Ponseti casts and tenotomy, the parents of a 4-month-old ask why their child must keep wearing the shoes-on-a-bar brace when the feet now look normal. What is the most appropriate counselling?

During the newborn check of a first-born girl delivered by breech, the paediatrician flexes the hips and knees, then gently abducts the left thigh while lifting the greater trochanter forwards; a clunk is felt as the head moves. What does this test show?

A 6-week-old girl has asymmetric thigh folds, and on examination the left hip feels unstable. Her mother asks which test will show the problem. What is the investigation of choice at this age?