Musculoskeletal / Other Common Cases

Marfan’s Syndrome

Marfan syndrome is the most common inherited connective tissue disorder in children and is diagnosed clinically. Children with Marfan’s often have a distinctive appearance that you can spot when you first walk into the room. They will often have a tall slim stature, with long slender limbs and fingers. They might have a family member (i.e. mother / sibling) with them who also has similar features. Take a step back and consider these clues that have been given to you.

Examination should follow a pGALS format (as demonstrated in the videos in this section. Remember that Marfan’s is a clinical diagnosis. Try to cover the following points:

Skeletal – disproportionately long limbs (span > height).

Hands – long slender finger digits (arachnodactyly). Steinberg sign (thumb projects beyond the ulnar border when apposed within the clenched fist). Positive wrist sign (distal phalanges of the first and fifth fingers of the hand overlap when wrapped around the opposite wrist).

Face – highly arched palate, dental crowding.

Eyes – you could ask about vision (thinking about the classic ectopia lentis = dislocation or subluxation of the lens, present ing approx 60-80% of patients, shown on examination by iridodonesis = tremor of iris, or phacodonesis = abnormal movement of the lens)

Chest – Pectus excavatum or carinatum. Demonstrate a quick cardiac examination – thinking of diltation of the aortic root with regurgitation (remember also risk of aortic aneurysm / dissection).

Skin – Skin striae seen commonly over the shoulders and buttocks

Back – scoliosis.

Neurofibromatosis type 1

The examiner may ask you to examine a child’s skin. This gives you a clue that you may be looking for NF1 or tuberosclerosis! Ask to get the child undressed so you can inspect fully. You need to learn the clinical criteria for NF1, and this forms the basis of your examination.

Clinical diagnosis of NF1 requires at least 2 of the following 7 criteria. Often these criteria will not be present until later in childhood, so full diagnosis may be delayed.

1. 6+ cafe-au-lait spots or hyperpigmented macules >5mm (pre-pubertal) or 15mm (post-pubertal).
2. Axillary or inguinal freckles – rarely present at birth, and appear during childhood through puberty.
3. Two or more typical neurofibromas, or one plexiform neurofibroma – classically seen in older children and adolescents, and rarely in young children. The numbers increase with puberty or pregnancy. These lesions may be deep and only detectable through palpation, so make sure you examine thoroughly.
4. Optic nerve glioma
5. 2+ Lisch nodules (iris hamartomas) – usually identified only through slit lamp examination by an ophthalmologist, but you could mention that you would like to look for this.
6. Sphenoid dysplasia or typical long-bone abnormalities, such as peudoarthrosis
7. First degree relative (mother, father, sibling) with NF1.

Important things to check on during each visit include:

• Blood pressure (risk of pheochromocytoma)
• Head circumference – should be monitored through the first 3 years of life. Risk of brain tumours – i.e. low-grade pilocytic astrocytomas.
• Height/weight on a growth chart

Tuberous Sclerosis

Tuberous sclerosis is another very common condition in the exam. As you walk into the room, you may be able to get a clue to the diagnosis from the often distinctive facial angiofibromas.

Tuberous sclerosis is usually a clinical diagnosis, from features found on examination. The criteria is based on major and minor features: either two major features, or one major and two minor features.

The diagnosis is “probable” if only one major and one minor feature. The diagnosis can be consider “possible” from just one major feature, or two minor features.

Major features

• Facial angiofibromas (an “acneiform lesion on the forehead”)
• Non-traumatic ungual or periungual fibromas
• 3+ hypomelanotic macules (ash leaf macules) – examined with an ultraviolet light (“Wood’s light”).
• Shagreen patch (a flesh coloured orange-peel naevus / appearance of thick leathery skin)
• Cortical tuber
• Subependymal nodules
• Subependymal giant cell astrocytoma
• Cardiac rhabdomyoma
• Lymphangiomyomatosis / renal angiomyolipoma
• Retinal hamartoma

Minor features

• Pits in dental enamel
• Hamartomatous rectal polyps
• Bone cysts
• Gingival fibromas
• Non-renal hamartoma
• Multiple renal cysts
• Skin tags
• Positive family history in a first degree relative

Common investigations that you might consider if asked in the following questions include: fundoscopy (retinal lesions), UV light (hypopigmented patches), MRI brain (cortical tubers, subependymal giant cell tumour, subependymal nodule), EEG (if causing epilepsy), assessment of renal function (renal USS/MRI) and hypertension, ECG (cardiac arrythmias – i.e. Wolff-Parkinson-White), echo (cardiac rhabdomyoma), CXR/high resolution CT (if pulmonary lymphangioleiomyomatosis is suspected).

Connective tissue disorders – Ehlers Danlos

Ehlers Danlos syndrome and other connective tissue disorders will likely be introduced to you as “Please examine this child’s joints” or “This boy has been complaining of joint pains – please examine him”.

A pGALS examination (as shown in the videos) is a good approach. Try to include a Beighton score (below) for assessing general joint hypermobility. Score 1 for each of the following items:

1. Passive apposition of the left thumb to the flexor aspect of the forearm
2. Passive apposition of the right thumb to the flexor aspect of the forearm
3. Passive dorsiflexion of the left little finger beyond 90 degrees
4. Passive dorsiflexion of the right little finger beyond 90 degrees
5. Hyperextension of the left elbow beyond 190 degrees
6. Hyperextension of the right elbow beyond 190 degrees
7. Hyperextension of the left knee beyond 190 degrees
8. Hyperextension of the right knee beyond 190 degrees
9. Ability to flex the trunk forward, with knees extended and palms resting flat on the floor

The score ranges from 0 to 9 (four items on left/right side, plus final manoeuvre), with 5 and above suggesting generalised joint hypermobility.

You might like to suggest also doing a cardiac examination at the end, as cardiovascular involvement is common (i.e. mild mitral, tricuspid, and aortic valve regurgitation).