MSK peds

Front

A 4-year-old boy presents with a limp and intermittent knee pain that worsens with activity. His parents report the symptoms have been ongoing for a few weeks, but the child denies any recent trauma. Physical examination reveals limited abduction and internal rotation of the hip, and the patient has a Trendelenburg gait. Radiographs reveal a small femoral epiphysis with sclerosis. What is the most likely diagnosis?

Back

Legg-Calvé-Perthes Disease

Answer explanation

Legg-Calvé-Perthes disease is caused by avascular necrosis of the femoral head and is commonly seen in boys aged 4-10. SCFE is less likely in this age group and typically occurs in overweight adolescents.

Exam findings: los of medial rotation and abduction.

Tx: Nsaids, bed rest, abduction bracing

Surgery for severe

Front

A 3-year-old boy is brought to the emergency department after being pulled by his arm while playing. He is holding his arm close to his body in a flexed and pronated position. There is no swelling or deformity, but the child resists using the arm. What is the most likely diagnosis?

Back

Radial Head Subluxation

Answer explanation

Nursemaid's elbow is common in 1-4 years old.

No bony tenderness

Front

A 15-year-old boy presents for evaluation of a spinal curvature noticed during a school screening. He denies back pain or any other symptoms. Radiographs show a 30-degree thoracic curve. What is the most appropriate next step in management?

Back

Prescribe a thoracolumbar brace

Answer explanation

DX: Forward bed and scoliometer

1. 0-15 unlikely to progress

15-25 monitor regularly

25-45 bracing vs operative

45+ opertive

60+ can lead to pulm compromise

For a Cobb angle between 25-45 degrees in a growing child, bracing is the standard treatment to prevent progression of the curve. Observation is appropriate for milder curves (<25 degrees), while surgery is considered for curves >45 degrees or if bracing fails. Physical therapy cannot correct structural scoliosis but may improve strength and mobility.

Front

A 6-year-old boy falls from a jungle gym and lands on his outstretched hand. He presents to the emergency department with swelling and pain around the elbow. His arm is held in a flexed position, and there is visible deformity at the distal humerus. On examination, there is tenderness over the distal humerus, and he is unable to move his fingers due to pain. Radial pulse is palpable, and capillary refill is less than 2 seconds.
What is the most likely diagnosis? Options: Clavicle Fracture, Monteggia Fracture, Radial Head Subluxation, Supracondylar Fracture

Back

Supracondylar Fracture

Answer explanation

A supracondylar fracture is a common elbow injury in children caused by falling on an outstretched hand. It presents with elbow swelling, deformity, and tenderness. The radial pulse and capillary refill should always be assessed due to the risk of vascular compromise.

Front

A 10-month-old infant presents with inconsolable crying and swelling of the left great toe, with redness and swelling around the toe but no reported trauma. What is the most likely diagnosis?

Back

Hair Tourniquet Syndrome

Front

A 4-year-old boy is brought to the clinic with a limp and refusal to bear weight on his right leg. His symptoms started 2 days ago and are associated with mild groin pain. The parents report that he had an upper respiratory infection a week ago. He is afebrile, and his physical exam reveals limited range of motion in the right hip due to discomfort. Laboratory results show a normal WBC count, ESR of 15 mm/hr, and CRP of 1.0 mg/dL.
What is the most likely diagnosis? Options: Transient Synovitis, Septic Arthritis, Legg-Calvé-Perthes Disease, Slipped Capital Femoral Epiphysis (SCFE)

Back

Transient Synovitis

Answer explanation

Transient synovitis is a self-limiting condition often following a viral illness, presenting with hip pain, a limp, and limited range of motion. The child is typically well-appearing, and inflammatory markers are usually normal or only mildly elevated.

Front

A 2-year-old boy presents to the emergency department with a 2-day history of fever, refusal to walk, and pain in the right hip. On examination, the right hip is held in a flexed and externally rotated position. The joint is swollen, warm, and tender to palpation. Laboratory studies show WBC 15,000/mm³, ESR 60 mm/hr, and CRP 5 mg/dL. What is the most likely diagnosis?

Back

Septic Arthritis

Answer explanation

Septic arthritis presents with acute onset of fever, joint pain, warmth, swelling, and inability to bear weight. Elevated inflammatory markers (WBC, ESR, CRP) strongly suggest an infectious process.

Krocher Criteria

Non-weight bearing

ESR> 40

Fever> 38.5

WBC> 12

CRP> 2

Front

A 3-year-old girl is evaluated for fever, a limp, and left knee pain. Her knee is swollen and warm, and she refuses to bear weight. Ultrasound reveals joint effusion, and laboratory tests show WBC 18,000/mm³, ESR 70 mm/hr, and CRP 6.5 mg/dL.
What is the next best step in management?

Back

Perform an urgent joint aspiration

Answer explanation

Joint aspiration is critical in diagnosing and treating septic arthritis, as it confirms the presence of infection through cell count, Gram stain, and culture. Delaying the aspiration risks joint destruction. NSAIDs or antibiotics alone are inappropriate without confirming the diagnosis. MRI may be helpful for deeper joints but is not the first step.

MC staph aureus

Group A strep > 5 years old

Group B Strep < 5 months

Neisseria gonorrhea = teenagers

Salmonella- sickle cell

Front

A 2-year-old boy is brought to the clinic with refusal to bear weight on his left leg. The parents report no trauma but mention he tripped while running two days ago. On examination, there is no visible swelling, but the child winces with gentle palpation of the distal tibia. What is the most likely diagnosis? Options: Transient Synovitis, Toddler’s Fracture, Septic Arthritis, Greenstick Fracture

Back

Toddler’s Fracture

Answer explanation

Most common ID'd fxr in preschool children with limp

Tx: Long leg cast immobilization

Front

What is NOT a risk factor for Hip Dysplasia development? Female, Breech birth, Fm Hx of DDH, Persistent hip asymmetry, Increased fetal mobility

Back

Increased fetal mobility

Answer explanation

Limited fetal mobility would be a RF