paediatric orthopaedics

Question 1

UMN signs

Answer 1

Upper motor neuron (UMN ‐ brain and spinal cord) causes give rise to weakness, spasticity (rate dependant increased tone), hyperreflexia and an extensor plantar response (Babinski sign).

Question 2

LMN signs

Answer 2

Lower motor neuron (LMN – affecting anterior horn cells, nerve roots or peripheral nerve) causes result in weakness, reduced tone and hypo‐ or areflexia.

Question 3

when is varus/valgus alignment normal?

Answer 3

Children at birth normally have varus knees (bow legs) which become neutrally aligned at around 14 months, progressing to 10 to 15° valgus (knock knees) at age 3 and then gradually regress to the physiologic valgus of 6° by around the age of 7‐9. Parents may often be concerned at the appearance however the vast majority develop normal alignment and most cases need reassurance only. Some people develop minor degrees of varus or valgus alignment which often can be familial.