normal_lower_limb_variants_flashcards
What is a common reason for presentation to primary care regarding lower limbs in children?
Apparent abnormalities in the lower limbs of developing children causing parental concern
Describe flat feet (pes planus).
Absent medial arch on standing
What is the typical age of presentation for flat feet?
All ages
What is the management approach for flat feet in children?
Typically resolves between the ages of 4-8 years; orthotics are not recommended; parental reassurance is appropriate
Describe in-toeing.
Common in the first year; possible causes include metatarsus adductus, internal tibial torsion, and femoral anteversion
What are some possible causes of in-toeing in the first year?
Metatarsus adductus, internal tibial torsion, femoral anteversion
What is metatarsus adductus?
Abnormal heel bisector line; 90% of cases resolve spontaneously, severe/persistent cases may require serial casting
What is internal tibial torsion?
Difference between the thigh and foot angle; resolves in the vast majority
What is femoral anteversion?
‘W’ sign; resolves in around 80% by adolescence, surgical intervention in the remaining not usually advised
Describe out-toeing.
Common in all ages, especially early infancy
What is the typical age of presentation for out-toeing?
Usually resolves by the age of 2 years
What is a common cause of out-toeing in early infancy?
External tibial torsion
What is the management approach if out-toeing doesn’t resolve?
Intervention may be appropriate as it increases the risk of patellofemoral pain
Describe bow legs (genu varum).
Increased intercondylar distance
What is the typical age of presentation for bow legs?
1st-2nd year; typically resolves by the age of 4-5 years
Describe knock knees (genu valgum).
Increased intermalleolar distance
What is the typical age of presentation for knock knees?
3rd-4th year; typically resolves spontaneously
summarise normal lower limb variants
A 13-month-old boy is taken to see his general practitioner by his mother. She reports that he recently started walking, but she has noticed that his legs appear strangely shaped, curving outward at the knees. He is otherwise well in himself and has no medical history of note. Both the pregnancy and delivery were straightforward.
On examination, the boy appears well in himself. The legs curve noticeably outward at the knees. The ankles touch and the toes point slightly outward.
What is the most appropriate next step?
Reassure the mother that it usually resolves by the age of 4
Reassure the mother that it usually resolves by the age of 8
Refer for a blood test to check vitamin D levels
Routine referral to paediatrics
Urgent referral to paediatrics
Bow legs in a child < 3 is a normal variant and usually resolves by the age of 4 years
The description in this scenario is suggestive of genu varum, or bow legs. This is a normal variant in children and can often become more noticeable when the child starts walking. It is often accompanied by out-toeing. In almost all cases, the only step needed is reassurance as the condition usually resolves by the age of 4.
Reassuring the mother that it usually resolves by the age of 8 is therefore incorrect. If it has not resolved by the age of 4, a referral for further investigation will be needed.
Referral for a blood test to check vitamin D levels is unwarranted here. Although bow legs may be caused by rickets, this is extremely rare in the developed world. In the absence of any other signs or symptoms, the most likely cause is simply normal variant bow legs.
Routine referral to paediatrics is unwarranted at this stage. If the bow legs do not resolve by the age of 4 or 5, this would be an appropriate step.
Urgent referral to paediatrics is incorrect. Bow legs are a normal variant in children of this age.
