Paeds - ortho + rheum Flashcards
What is osteogenesis imperfecta?
A genetic condition that causes a range of mutations to the formation of collagen.
(There are 8 different kinds of OI depending on what the underlying genetic mutation is)
Results in brittle bones that are prone to fractures.
How would osteogenesis imperfecta present?
- hypermobility
- blue/grey sclera
- triangular face
- short stature
- deafness from early adulthood
- dental problems, eg. with the formation of teeth
- bone deformities eg. bowed legs and scoliosis
- joint and bone pain
How would you manage osteogenesis imperfecta?
- Bisphosphonates to increase bone density
- Vitamin D supplementation to prevent deficiency
- Physiotherapy and occupational therapy to maximise strength and function
- Surgery to manage fractures
- Social workers for social and financial support
- Specialist nurses
- Paediatric follow up
What is DDH?
Developmental Dysplasia of the Hip is where there is a structural abnormality with the development of the hip bones during foetal development.
Risk factors are the 5 Fs
- Female
- Firstborn
- Fhx
- Fanny first (breech)
- Fluid (oligohydramnios)
How would you pick up a baby with DDH?
- it is screened for on the neonatal examination at birth and at 6-8 weeks old
- Findings that suggest DDH in the Newborn and Infant Physical Examination (NIPE)…
- Different leg lengths
- Restricted hip abd on one side
- Significant bilateral restriction in abd
- Difference in the knee level when the hips are flexed
- Clunking of the hips on special tests (clicking is more common and usually not conerning)
- Ortolani test
- Barlow test
- Diagnostic = US of hips if kids have any risk factors or concerning examination findings suggestive of DDH
What are the special tests used in the newborn and infant physical examination to check for DDH?
Ortolani test
- baby on their back with hips and knees flexed
- palms placed on babys knees with thumbs on inner thigh and 4 fingers on outer thigh
- use gentle pressure to abd hips and apply pressure behind the legs with fingers to see if hips will dislocate anteriorly
Barlow test
- baby on their back with hips adducted and flexed at 90 degrees, and knees bent 90 degrees
- gentle pressure on knees through femur to see if femoral head will dislocate posteriorly
Galleazis test
- to indicate whether leg shortening is femoral or tibial
What are some risk factors for DDH?
- 1st degree family history
- breech presentation from 36 weeks onwards
- breech presentation at birth from 28 weeks onwards
- multiple pregnancy
How would you manage DDH?
-
Pavlik harness if the baby presents at less than 6 months old
- keep it on permanently, adjusting for growth
- it holds the femoral head in the correct position to allow the hip socket (acetabulum) to develop a normal shape
- it keeps the babys hips flexed and abducted
- regularly review baby and can remove harness when hips are more stable, usually after 6-8 weeks
- Surgery if harness fails or baby presents after 6 months of age
- use a hip spica cast to immobilise hip afterwards
What is a talipes?
Also called “clubfoot”, It is a fixed abnormal ankle position that presents at birth.
Talipes equinovarus = ankle in plantar flexion and supination
Talipes calcaneovalgus = ankle in dorsiflexion and pronation
What is positional talipes?
Positional talipes = resting ankle position is in plantar flexion and supination. However it is not fixed and can be moved back to normal position. There is no structural boney problem, the muscles are just slightly tight around the ankle.
Manage with physiotherapist and it will resolve over time.
How would you manage talipes?
-
Ponseti method started almost immediately after birth
- foot is manipulated towards normal position and a cast is applied to hold it in position
- this is repeated until the foot is in the correct position
- sometimes an achilles tenotomy to release tension in the achilles tendon is performed in clinic
- Finally, once treatment with the cast is finished a brace is used to hold the feet in the correct position when not walking, until child is 4 years old
What is achondroplasia?
- It is the most common cause of disproportionate short stature (dwarfism).
- It is a type of skeletal dysplasia
- occurs due to a sporadic mutation or ineritance of an abnormal copy of the FGFR3 gene (Fibroblast growth factor receptor 3) on Chromosome 4
- this causes abnormal function of the epiphyseal plates which restricts bone growth in length
- Autosomal dominant
- Homozygous gene mutations are fatal in the neonatal period
- All patients with achondroplasia are heterozygous
What are some features of achondroplasia?
- disproportionate short stature (average around 4 feet)
- proximal limbs (femur and humerus) are more affected than bones of forearm and lower leg.
- Spine is least affected and most patients have a normal trunk length
- Short digits
- bow legs (genu varum)
-
disproportionate skull
- flattened mid-face and nasal bridge
-
foramen magnum stenosis
- can lead to cervial cord compression and hydrocephalus
- cranial vault grows and fuses via membranous ossification (unaffected by achondroplasia) and leads to a normal sized vault and frontal bossing (prominent forehead)
- recurrent otitis media due to cranial abnormalities
- associated with kyphoscoliosis, spinal stenosis
How would you manage achondroplasia?
- MDT supportive management (dieticians, physiotherapists, occupational therapists, orthopaedic and ENT surgeons, paediatricians, specialist nurses)
- Leg lengthening surgery to add height but is controversial and can cause chronic pain and reduced function
What is Rickets?
- A condition affecting children where there is defective bone mineralisation causing soft deformed bones (in adults this is osteomalacia)
- It is due to vitamin D or calcium deficiency
- Vit D is produced in response to sunlight or obtained through eggs, oily fish, fortified cereals or supplements
- Calcium is found in dairy products and green vegetables
- A rare form of rickets caused by low phosphate in the blood = hereditary hypophosphataemic rickets
Describe the pathophysiology of rickets
- Vitamin D is created from cholesterol by the skin in response to UV radiation
- those with darker skin require a longer period in the sun to generate the same quantity of vit D
- An average diet contains inadequate levels of vit D to compensate for lack of sun exposure, so people with reduced exposure should take vit D supplementation
- Diseases like IBD or other malabsorption disorders and CKD (kidneys metabolise vit D to its active form calcitriol) are associated with vitamin D deficiency
- Vitamin D is essential for calcium and phosphate absorption from the intestines and kidneys
- Calcium and phosphate are required for construction of bone so low levels result in defective bone mineralisation
- Low calcium causes secondary hyperparathyroidism
- parathyroid gland tries to raise Ca2+ level by s_ecreting parathyroid hormone_
- PTH stimulates increased reabsorption of Ca2+ from the bones, which causes more problems with bone mineralisation
How would rickets present?
- lethargy
- bone pain
- swollen wrists
- bone deformity
- poor growth
- dental problems
- muscle weakness
- pathological or abnormal fractures
Bone deformities…
- bowing of the legs (legs curve outwards)
- knock knees (legs curve inwards)
- rachitic rosary (ends of ribs expand at costochondral junctions, causing lumps on the chest)
- craniotabes (soft skull) with delayed closure of sutures and frontal bossing
- delayed teeth + underdevelopment of enamel
How would you investigate rickets?
- serum 25-hydroxyvitamin D of <25nmol/L = vitamin D deficiency
- Xray to diagnose rickets
- can show osteopenia (more radiolucent bones)
- Serum calcium may be low
- serum phosphate may be low
- serum alkaline phosphatase may be high
- parathyroid hormone may be high
Look for other pathologies…
- FBC and ferritin for iron deficiency anaemia
- ESR and CRP for inflammatory conditions
- U&Es for kidney disease
- LFTs for liver pathology
- TFTs for hypothyroidism
- Malabsorption screen like anti-TTG antibodies for coeliac
- Autoimune and Rheumatoid tests
How would you manage rickets?
Main management is prevention:
- breast fed babies are at a higher risk of vitamin D deficiency!
- formula feed is fortified with vitamin D
- Breastfeeding women and all children should take vitamin D supplements
- 400IU (10mcg) per day for children
Management:
- Treat vitamin D deficiency with Vitamin D (ergocalciferol)
- 6 months-12 years old = 6000IU/day for 8-12 weeks
- Refer kids with rickets symptoms to a paediatrician
- treat rickets with Vitamin D and Calcium supplements
What is the difference between children bones/fractures to adult bones/fractures?
- Children have growth plates
- Children bones have more cancellous bone (spongier, highly vascular bone in the centre of long bones)
- this makes their bones more flexible but less strong than adult bones that have more cortical bone (compact hard bone)
- Therefore children are more prone to greenstick fractures (one side of the bone breaks while the other side stays intact)
- Children are also more likely to have buckle fractures due to less strength against compression
- Childrens bones have a better blood supply so heal more quickly with less deformity than adults
- Childrens bones have a higher capacity for remodelling so even if they are set at an incorrect angle, they can remodel over time to return to the correct shape
What classification is used for fractures through the growth plate?
Salter-Harris classification
SALTR mneumonic
Type 1 = Straight across
2 = Above
3 = Below
4 = Through
5 = Crush
How would you generally manage a fracture in a child?
Pain management: WHO pain ladder
- 1st line = paracetamol or ibuprofen
- 2nd line = morphine
- We do not use codeine and tramadol in kids as there is unpredictability in their metabolism
- Aspirin is contraindicated in <16 year olds due to risk of Reye’s syndrome (only used in certain circumstances like Kawasaki disease)
- Safeguarding!!!
- Mechanical alignment
- via Closed reduction (manipulation of the joint)
- or Open reduction in surgery
- Provide relative stability to allow healing
- via external casts, K wires, intramedullary wires and nails, plates and screws
What are some classical causes of hip pain a kids?
0-4
5-10
10-16
0-4 years old
- septic arthritis
- DDH
- transient sinovitis
5-10
- septic arthritis
- transient sinovitis
- perthes disease
10-16
- septic arthritis
- slipped upper femoral epiphysis (SUFE)
- juvenile idiopathic arthritis
What criteria does NICE say to urgently refer a limping child for assessment?
- <3 years old
- >9 years old with a restricted or painful hip
- not able to weight bear
- evidence of neurovascular compromise
- severe pain or agitation
- suspicion of abuse
-
red flags for serious pathology
- child <3 years old
- fever
- waking at night with pain
- weight loss
- anorexia
- night sweats
- fatigue
- persistent pain
- stiffness in the morning
- swollen or red joint
Septic arthritis is an infection inside a joint and is an emergency!!!
Recognition is essential, how would it present?
- affects a single joint (often knee or hip)
- rapid onset of…
- hot red swollen painful joint
- refusing to weight bear
- stiffness and reduced range of motion
- systemic symptoms such as fever, lethargy, sepsis
Can be subtle in young kids so suspect it if a kid has joint problems
(other differentials = Transient Sinovitis, Perthes disease, SUFE, Juvenile idiopathic arthritis)
What are some common bacteria in septic arthritis?
Commonly Staphylococcus aureus
- Neisseria gonorrhoea (in sexually active teens)
- Group A Strep like Streptococcus pyogenes
- Haemophilus influenza
- Eschericia coli
How would you manage septic arthritis?
have a low threshold for treating septic arthritis, until it has been excluded with examination of joint fluid
- admit to hospital and refer to orthopaedic team
-
aspirate joint prior to antibiotics
- send for Gram staining, crystal microscopy, culture and antibiotic sensitivities
- Give empirical IV antibiotics until microbial sensitivities are known
- continue for 3-6 weeks when septic arthritis is confirmed
- Sometimes may require surgical drainage and washout of joint to clear infection in severe cases
