A 3-year-old is brought for a limp. The parents say that at 3 weeks of age he had a hot, swollen right hip that was treated with oral medicines from a local practitioner. X-ray now shows complete loss of the right femoral head with the neck riding high, outside the acetabulum. What is the most likely diagnosis?

Developmental dysplasia of the hip

Bone and joint infections, TB spine

22 NEET-PG practice questions on Bone and joint infections, TB spine, 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 · Easy
A 9-year-old boy with sickle cell anaemia from a tribal district of Odisha has fever and a painful swollen forearm. MRI confirms osteomyelitis of the radius. With which organism is osteomyelitis characteristically associated in children with sickle cell disease?
1. ANeisseria gonorrhoeae
2. BPseudomonas aeruginosa
3. CKingella kingae
4. DSalmonella species
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Answer: D · Salmonella species
Children with sickle cell disease characteristically develop Salmonella osteomyelitis, often in diaphyses and at several sites. Bowel infarcts let Salmonella into the blood, functional asplenia lowers clearance, and infarcted bone gives a site for infection. Staphylococcus aureus still causes many cases, so empirical treatment must cover both. Bone infarction (crisis) is the main differential and can look similar on imaging.
- A: Gonococcus causes septic arthritis in sexually active adults, not osteomyelitis in sickle cell.
- B: Pseudomonas is linked to puncture wounds through footwear and to drug users.
- C: Kingella causes joint and bone infection in children under about 4 years.
Question 2 · Medium
A 3-year-old is brought for a limp. The parents say that at 3 weeks of age he had a hot, swollen right hip that was treated with oral medicines from a local practitioner. X-ray now shows complete loss of the right femoral head with the neck riding high, outside the acetabulum. What is the most likely diagnosis?
1. ACoxa vara of the femoral neck
2. BPerthes disease
3. CDevelopmental dysplasia of the hip
4. DTom Smith arthritis
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Answer: D · Tom Smith arthritis
Tom Smith arthritis is septic arthritis of the hip in infancy in which the cartilaginous femoral head is destroyed by pus and raised joint pressure. The head may disappear completely and the neck dislocates, leaving a short, unstable limb. It is prevented by urgent drainage of an infected infant hip. Reconstruction later is difficult and results are poor.
- A: Coxa vara reduces the neck-shaft angle without destroying the head.
- B: Perthes disease affects children of about 4-8 and causes fragmentation, not total loss.
- C: DDH dislocates a head that is present and has no infective history.
Question 3 · Hard
A 5-year-old boy is brought to casualty with right hip pain since yesterday. He refuses to stand. Temperature 39.2 °C, ESR 55 mm/h, WBC 16,800/µL; ultrasound shows a hip effusion. Consider these steps: 1. Aspirate the hip under ultrasound or in theatre. 2. Send fluid for Gram stain, cell count and culture. 3. Wait for culture results before deciding on drainage. 4. Arrange urgent surgical drainage if pus is aspirated. Which steps are correct?
1. A1, 3 and 4 only
2. B1, 2 and 4 only
3. C1 and 3 only
4. D2 and 3 only
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Answer: B · 1, 2 and 4 only
The boy meets all four Kocher criteria (non-weight-bearing, temperature above 38.5 °C, ESR above 40 mm/h, WBC above 12,000/µL), which gives a very high probability of septic arthritis rather than transient synovitis. The hip is aspirated, the fluid is sent for Gram stain, count and culture, and pus means urgent drainage and IV antibiotics. Waiting for culture is wrong: raised pressure inside the hip can cause avascular necrosis and destroy the head within days.
- A: Includes waiting for culture and leaves out sending the fluid for tests.
- C: Includes waiting for culture and leaves out urgent drainage of pus.
- D: Includes waiting for culture, which delays drainage and risks head destruction.
Question 4 · Hard
A 35-year-old man with back pain has an MRI that must be reported as tuberculous or pyogenic spondylodiscitis. Consider these features: 1. Spread under the anterior longitudinal ligament to several vertebrae. 2. A large paraspinal abscess with a thin, smooth enhancing wall. 3. Early and marked destruction of the disc with relative sparing of bone. 4. Skip lesions at distant levels. Which features favour tuberculosis?
1. A1, 2 and 4 only
2. B1, 3 and 4 only
3. C3 and 4 only
4. D2 and 3 only
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Answer: A · 1, 2 and 4 only
Features 1, 2 and 4 favour tuberculosis. TB spreads under the anterior longitudinal ligament over several levels, forms large, well-defined cold abscesses with thin smooth walls, and can produce skip lesions. In pyogenic infection the proteolytic enzymes of bacteria destroy the disc early and rapidly, and abscesses are smaller with thick irregular walls. These MRI clues guide, but biopsy with microbiology confirms the diagnosis.
- B: Includes early disc destruction, which favours pyogenic infection.
- C: Includes feature 3, a pyogenic feature, and omits features 1 and 2.
- D: Includes early disc destruction, a pyogenic feature, and omits subligamentous spread.
Question 5 · Easy
Which is the commonest type of lesion in tuberculosis of the spine?
1. AParadiscal
2. BPosterior arch (appendicular)
3. CCentral (vertebral body)
4. DAnterior (subperiosteal)
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Answer: A · Paradiscal
Paradiscal lesions, involving the adjacent margins of two vertebral bodies and the disc between them, are the commonest form of spinal tuberculosis. The infection spreads from the metaphyseal parts of the bodies, and the disc space narrows early. Central lesions destroy one body and can mimic a tumour, anterior lesions spread under the anterior longitudinal ligament, and posterior arch lesions are uncommon.
- B: Posterior arch involvement is uncommon in spinal tuberculosis.
- C: Central lesions affect a single body and are less common; they mimic tumour.
- D: Anterior lesions spread under the anterior ligament and are less common.
Question 6 · Medium
A 50-year-old woman presents with fever and a hot, swollen right knee for 2 days. Knee aspirate: turbid fluid, WBC 82,000/µL with 94% neutrophils, no crystals under polarised light, Gram stain negative. What is the most appropriate management?
1. AAwait culture before any antibiotic
2. BOral NSAID and rest for 1 week
3. CIV antibiotics with urgent joint washout
4. DIntra-articular steroid injection
Answer and explanation in LearnFree account
Question 7 · Hard
A 68-year-old man with gout and type 2 diabetes has fever of 38.8 °C and a hot, swollen left knee for 2 days. Aspirate: WBC 115,000/µL, 95% neutrophils, needle-shaped negatively birefringent crystals present, Gram stain shows gram-positive cocci in clusters. What is the most appropriate management?
1. ATreat as acute gout with colchicine alone
2. BTreat as septic arthritis with antibiotics and washout
3. CStart allopurinol and an oral NSAID
4. DInject intra-articular steroid for gout
Answer and explanation in LearnFree account
Question 8 · Easy
A 30-year-old farm labourer has had a discharging sinus on the front of the leg for two years after an untreated tibial infection. X-ray shows a thickened tibia with a dense, sharply outlined fragment of bone lying free in a cavity, surrounded by new bone. What is the dense free fragment called?
1. ACloaca
2. BSequestrum
3. CInvolucrum
4. DBrodie abscess
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Question 9 · Medium
A 58-year-old man has had a discharging sinus over the shin for 25 years after an open tibial fracture. Over the past 3 months the sinus opening has become an enlarging ulcer with heaped-up, everted edges and foul bleeding discharge. What is the most likely diagnosis?
1. ASquamous cell carcinoma in the sinus tract
2. BTuberculous ulcer of the skin
3. CBasal cell carcinoma of the leg
4. DRecurrence of acute osteomyelitis
Answer and explanation in LearnFree account
Question 10 · Medium
A 64-year-old man has severe back pain for 2 months and weight loss. MRI shows collapse of the L2 vertebral body with destruction of the left pedicle, while the L1-L2 and L2-L3 disc spaces are preserved; there is no paraspinal collection. Which diagnosis do these findings favour?
1. AOsteoporotic wedge fracture
2. BPyogenic spondylodiscitis
3. CMetastatic deposit in the vertebra
4. DParadiscal tuberculosis of the spine
Answer and explanation in LearnFree account
Question 11 · Medium
Why does acute haematogenous osteomyelitis in children usually begin in the metaphysis of long bones?
1. AThe metaphysis has the thinnest cortex of the bone
2. BHairpin capillary loops slow the blood flow there
3. CGrowth plate cartilage releases bacterial toxins
4. DThe metaphysis lacks a periosteal covering
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Question 12 · Medium
A 26-year-old man treated for pulmonary TB two years ago has dull low back pain for 5 months. He now has a soft, non-tender, fluctuant swelling in the right groin just below the inguinal ligament, and the right hip is held slightly flexed; extending the hip is painful, but rotation in flexion is free. What is the most likely cause of the groin swelling?
1. ATuberculous inguinal lymphadenitis
2. BFemoral hernia with omentum
3. CSeptic arthritis of the right hip
4. DPsoas abscess from lumbar spinal tuberculosis
Answer and explanation in LearnFree account
Question 13 · Easy
A 7-year-old boy from a village near Nashik has fever for 3 days and refuses to bear weight on the left leg. There is exquisite tenderness over the upper end of the tibia, the knee joint moves freely, and the WBC count is 17,500/µL with raised CRP. Which organism is most likely?
1. AHaemophilus influenzae type b
2. BSalmonella Typhi
3. CStreptococcus pyogenes
4. DStaphylococcus aureus
Answer and explanation in LearnFree account
Question 14 · Hard
A 38-year-old man has TB of T8-T9 on MRI with an anterior epidural abscess and is started on anti-tubercular treatment and bed rest. On day 1 he can lift both legs against gravity. Over the next 3 weeks the power falls to a flicker in both legs, and he develops urinary retention. What is the most appropriate step?
1. AHigh-dose steroids in place of surgery
2. BSurgical decompression of the cord
3. CAdd a second-line anti-TB regimen empirically
4. DContinue the same treatment for 3 more months
Answer and explanation in LearnFree account
Question 15 · Easy
A 15-year-old boy has had a dull ache in the lower tibia for 4 months, worse at night, without fever. X-ray shows a well-defined round lucency about 2 cm across in the distal tibial metaphysis with a thick sclerotic rim. Curettage yields pus that grows Staphylococcus aureus. What is the diagnosis?
1. AChronic osteomyelitis with sequestrum
2. BBrodie abscess
3. COsteoid osteoma
4. DGarre sclerosing osteomyelitis
Answer and explanation in LearnFree account
Question 16 · Medium
A 4-year-old girl living with a grandparent on treatment for pulmonary TB has a painless, spindle-shaped swelling of the proximal phalanx of the left middle finger for 2 months. X-ray shows expansion of the phalanx with a thin, ballooned cortex. What is the most likely diagnosis?
1. AAcute pyogenic osteomyelitis
2. BSickle cell dactylitis
3. CSpina ventosa (tuberculous dactylitis)
4. DEnchondroma of the phalanx
Answer and explanation in LearnFree account
Question 17 · Hard
A 6-year-old girl with acute osteomyelitis of the distal femur, confirmed on MRI, has received IV cloxacillin for 72 hours. She is still febrile at 39 °C, the thigh is more swollen and tender, and CRP has risen from 80 to 140 mg/L. Blood culture grew methicillin-sensitive Staphylococcus aureus. What is the next best step?
1. ARepeat MRI and surgically drain any abscess
2. BAdd oral rifampicin to the regimen
3. CContinue the same antibiotic for 3 more days
4. DChange cloxacillin to vancomycin
Answer and explanation in LearnFree account
Question 18 · Medium
A 3-week-old neonate in the NICU, born at 32 weeks and treated for sepsis, has a swollen right thigh and does not move the leg. Ultrasound shows a hip effusion and MRI shows osteomyelitis of the upper femoral metaphysis. Why does metaphyseal infection spread so readily into the joint at this age?
1. AThe periosteum is thick and firmly attached
2. BVessels cross the growth plate into the epiphysis
3. CThe joint capsule ends below the metaphysis
4. DNeonatal bone has no marrow cavity
Answer and explanation in LearnFree account
Question 19 · Medium
A 22-year-old woman has fever, pain moving from wrist to ankle, and swelling along the tendons on the back of the hand for 4 days. Two painless pustules are seen on the forearm, and the right knee now has an effusion. Aspirate shows 38,000 WBC/µL, mostly neutrophils, with no organisms on Gram stain. What is the most appropriate antibiotic?
1. ACeftriaxone
2. BDoxycycline alone
3. CVancomycin
4. DCloxacillin
Answer and explanation in LearnFree account
Question 20 · Medium
A 70-year-old woman had a total knee replacement 14 months ago. She now has persistent knee pain, mild swelling and a small sinus near the scar, with no fever. X-ray shows a lucent line around the tibial component. The surgeon suspects a low-grade infection. Which organism is most typical of this picture?
1. AStreptococcus pneumoniae
2. BNeisseria gonorrhoeae
3. CEscherichia coli
4. DCoagulase-negative staphylococci
Answer and explanation in LearnFree account
Question 21 · Medium
A 30-year-old woman at a district hospital in Uttar Pradesh has back pain for 4 months with evening fever and weight loss. MRI shows destruction of adjacent margins of T11 and T12 with disc narrowing and a paraspinal abscess. Sputum is negative for TB. Under NTEP, what is the best next step to confirm the diagnosis?
1. AStart anti-tubercular treatment on the MRI picture
2. BCT-guided biopsy for CBNAAT, histology and culture
3. CSerum IgM and IgG antibodies against TB
4. DMantoux test and ESR
Answer and explanation in LearnFree account
Question 22 · Medium
A 10-year-old girl has had fever for 3 days with severe pain and tenderness over the lower femoral metaphysis. CRP is 96 mg/L (reference below 5). Plain X-ray of the femur is normal. What is the best investigation to confirm the diagnosis now?
1. ARepeat plain X-ray after 2 weeks
2. BTechnetium bone scan of the whole skeleton
3. CMRI of the femur
4. DCT scan of the femur
Answer and explanation in LearnFree account

Bone and joint infections, TB spine

A 9-year-old boy with sickle cell anaemia from a tribal district of Odisha has fever and a painful swollen forearm. MRI confirms osteomyelitis of the radius. With which organism is osteomyelitis characteristically associated in children with sickle cell disease?

Which is the commonest type of lesion in tuberculosis of the spine?

A 50-year-old woman presents with fever and a hot, swollen right knee for 2 days. Knee aspirate: turbid fluid, WBC 82,000/µL with 94% neutrophils, no crystals under polarised light, Gram stain negative. What is the most appropriate management?

A 30-year-old farm labourer has had a discharging sinus on the front of the leg for two years after an untreated tibial infection. X-ray shows a thickened tibia with a dense, sharply outlined fragment of bone lying free in a cavity, surrounded by new bone. What is the dense free fragment called?

A 58-year-old man has had a discharging sinus over the shin for 25 years after an open tibial fracture. Over the past 3 months the sinus opening has become an enlarging ulcer with heaped-up, everted edges and foul bleeding discharge. What is the most likely diagnosis?

A 64-year-old man has severe back pain for 2 months and weight loss. MRI shows collapse of the L2 vertebral body with destruction of the left pedicle, while the L1-L2 and L2-L3 disc spaces are preserved; there is no paraspinal collection. Which diagnosis do these findings favour?

Why does acute haematogenous osteomyelitis in children usually begin in the metaphysis of long bones?

A 7-year-old boy from a village near Nashik has fever for 3 days and refuses to bear weight on the left leg. There is exquisite tenderness over the upper end of the tibia, the knee joint moves freely, and the WBC count is 17,500/µL with raised CRP. Which organism is most likely?

A 15-year-old boy has had a dull ache in the lower tibia for 4 months, worse at night, without fever. X-ray shows a well-defined round lucency about 2 cm across in the distal tibial metaphysis with a thick sclerotic rim. Curettage yields pus that grows Staphylococcus aureus. What is the diagnosis?

A 4-year-old girl living with a grandparent on treatment for pulmonary TB has a painless, spindle-shaped swelling of the proximal phalanx of the left middle finger for 2 months. X-ray shows expansion of the phalanx with a thin, ballooned cortex. What is the most likely diagnosis?

A 3-week-old neonate in the NICU, born at 32 weeks and treated for sepsis, has a swollen right thigh and does not move the leg. Ultrasound shows a hip effusion and MRI shows osteomyelitis of the upper femoral metaphysis. Why does metaphyseal infection spread so readily into the joint at this age?

A 10-year-old girl has had fever for 3 days with severe pain and tenderness over the lower femoral metaphysis. CRP is 96 mg/L (reference below 5). Plain X-ray of the femur is normal. What is the best investigation to confirm the diagnosis now?