age features
What % of body weight is muscle mass in a newborn and in an adult?
Newborn 23.3%, adult 44.2%.
Which tooth sign suggests congenital syphilis?
Hutchinson incisors.
Which joint is most often affected in joint disease?
Knee.
From birth to adulthood, by how many times do the head, trunk and legs grow?
Head ×2, trunk ×3, legs ×5
Name four signs of osteoid hyperplasia in rickets.
Any four of: frontal/parietal bosses, bracelets, rosary, strings of pearls.
After birth, which tissue grows more, muscle or skeleton, and by how many times?
Muscle grows 37×, skeleton 27×
What does a bulging, strongly pulsating anterior fontanelle mean? What does a sunken one mean?
Bulging with strong pulsation means raised intracranial pressure. Sunken means dehydration.
Which symptom points to a rheumatic cause?
Morning stiffness.
State the rule of nines (children over 1 y).
Head 9, each arm 9, each leg 18, trunk 18 + 18.
What are the typical lab and X-ray findings in rickets?
Lab: ↑ alkaline phosphatase, ↓ phosphorus, sometimes ↓ Ca. X-ray: osteoporosis.
How many milk teeth do you expect in a 15-month-old, and how many permanent teeth in a 9-year-old?
Milk teeth = n − 4 = 11. Permanent teeth = 4n − 20 = 16.
Describe the recoil test and what a normal result is.
Extend the legs, press for 5 s, then release. Normal is an instant return.
List the steps of the floating patella test.
Extend the knee and squeeze with both palms. Push fluid up from the pocket. Tap the patella. If it floats freely, there is effusion.
Calculate the expected head circumference of a 7-year-old.
50 + (2 × 0.6) = 51.2 cm.
Where are the bracelets, the rosary and the strings of pearls found?
Bracelets: thick distal radius epiphyses. Rosary: swellings beside the sternum. Strings of pearls: thick phalanges.
Bone turnover is 100–200% in year 1. What two clinical consequences follow?
Bone is soft, flexible and easily deformed. The rich metaphyseal blood supply predisposes to osteomyelitis.
Compare the vertical suspension test in hypotonia and in hypertonia.
Hypotonia: head and legs hang. Hypertonia: head thrown back.
Choose the first test for (a) suspected osteomyelitis, (b) suspected rickets, (c) weakness from nerve disease.
(a) X-ray. (b) Ca, P, alkaline phosphatase. (c) EMG, enzymes, biopsy.
A 1-year-old has a Chulitsky index of 15. Interpret it.
The normal value is 20–25 at 1 y. A fall like this suggests undernutrition.
Describe the clinical course of acute hematogenous osteomyelitis.
Fever comes first, with bone pain after days. Then oedema, red skin and signs of pus.
A child has acidosis. Which stage of bone formation is slowed, what does that stage need, and which hormone drives the last stage?
It needs Ca, P, vit D and trace elements. Remodeling (stage 3) is driven by parathyroid hormone plus vit D.
A term newborn lies flat with all limbs extended. What is this, what is normal for a term newborn, and what does a tone change in a newborn usually mean?
This is hypotonia. A term newborn normally has flexed elbows and hips/knees drawn up. Tone changes in a newborn usually mean CNS damage.
Describe the EMG pattern in neurogenic, myogenic and myasthenic conditions. What joint complication occurs in hemophilia?
Neurogenic: large potentials. Myogenic: unchanged. Myasthenia: amplitude falls to zero. Hemophilia causes hemarthrosis, leading to deformity and muscle atrophy
A 12-year-old has an upper:lower segment ratio of 1.5:1. Is this expected? Which index shows *when* a growth delay occurred?
No. The ratio should approach 1 at puberty, so 1.5 is an early-weeks value. The leg : upper-face index shows when growth delay occurred.
An 8-month-old has craniotabes, a late-closing fontanelle, rosary beads and bowed legs. Lab: ↑ALP, ↓P. Give the diagnosis, two more expected signs, and what to consider if it starts after 1 year.
Rickets. Other expected signs: boat-shaped chest, delayed teeth, kyphosis of the lower thoracic spine, bracelets. If it starts after 1 year, consider late rickets, vitamin D metabolism disorders, or renal rickets (tubular phosphate loss).