Paeds MSK/Rhem Flashcards
Define DDH
Structural abnormality in the hips leading to instability and potential for subluxation or dislocation
What are the 6 RF for DDH
- First degree Fx
- Female
- Breech presentation
- High birth weight
- Oligohydramnios
- Prematurity
When is DDH screened for ?
-Neonatal examination at birth and at 6-8 weeks
What findings on a NIPE may suggest DDH?
- Different leg lengths
- Restricted hip abduction on one side
- Significant bilateral restriction in abduction
- Difference in the knee level when hips are flexed
- Clunking of the hips on special tests
What are the 2 special tests to look for DDH?
- Ortolani test
- Barlow test
What is the ortolani test ?
- Looks for DDH
- With the hips and knees flexed, gentle pressure is used to abduct the hips and apply pressure behind the legs to see if the hips will dislocate anteriorly
What is the barlow test ?
- Looks for DDH
- Gentle downward pressure is placed on the knees through the femur to see if the femoral head with dislocate posteriorly.
What is the diagnostic test for DDH?
-USS
How is DDH managed if presents at <6 mnths ?
- Pavlik harness
- Keeps the baby’s hips flexed and abducted.
- Usually on for 6-8 weeks.
How is DDH managed if presents >6 mnths or if harness fails?
- Surgery
- After surgery an hip spica cast is used to immobilise the hips
Define osteogenesis imperfecta
-Genetic condition resulting in brittle bones that are prone to fracture
What causes osteogensis imperfecta ?
- Genetic mutations that affect the formation of collagen
- 8 different genetic abnormalities with varying severities
How does osteogenesis imperfecta present ?
- Recurrent and inappropriate fractures
- Hyper-mobility
- Blue/grey sclera
- Triangular face
- Short stature
- Deafness from early childhood
- Dental problems
- Bone deformities : esp bowed legs and scoliosis
- Joint and bone pain
How is osteogenesis imperfecta diagnosed ?
- Usually clinical
- X-ray used in fractures and for bone deformitis
How is osteogenesis imperfecta managed ?
- Bisphosphonates to increased bone density (e.g. alendronate)
- Vit D supplementation to prevent deficiency
- Physio and occupational therapy
Define rickets
-Defective bone mineralisation causing ‘soft’ and deformed bones
What 2 vitamin deficiencies cause rickets ?
- Vitamin D
- Calcium
What are the sources of vitamin D?
- Sunlight
- Eggs, oily fish or forified cereals
What are the sources of calcium ?
- Dairy productes
- Green vegetables
What is a rare form of rickets?
- Hereditary hypophosphataemic rickets
- Genetic defect causing low phosphate
- Most common : X-linked dominant
What are the potential symptoms of rickets ?
- Lethargy
- Bone pain
- Swollen wrists ! widening of joint space
- Bone deformity
- Poor growth
- Dental problems ! no teeth development
- Muscle weakness
- Pathological or abnormal fractures
What 5 bone deformities can occur in rickets?
- Bowing of the legs
- Knock knees
- Rachitic rosary : ribs expand at the costochondral junctions causing lumps along the chest
- Craniotabes : soft skull with delayed closure of sutures and frontal bossing
- Delayed teeth
What are the RF for rickets ?
Anything that increases the risk of vit d deficiency
- Darker skin
- Low exposure to sunlight
- Live in colder climates
- Spend majority of their time indoors
What are the 5 common blood results in rickets ?
- Serum 25-hydroxyvitamin D of less than 25 nmol/L
- Calcium : low
- Phosphate : low
- Alkaline phosphatase : high
- Parathyroid hormone : high
What investigation is required to diagnose rickets ?
- X ray
- May show joint widening and osteopenia (more radiolucent bones)
How is rickets prevented ?
- Breastfeeding women should taken vitamin D supplements (10 micrograms per day)
- Formula fed babies are at lower risk as it is fortified with vitamin D
How is rickets managed ?
- Vitamin D (ergocalciferol) : 6mnths to 12 yrs is 6,000 IU per day for 8-12 wks
- Calcium supplementation
Explain the pathophysiology behind rickets
- Low vitamin D
- This leads to malabsorption of calcium and phosphate
- Low calcium and phosphate leads to defective bone mineralisation
- Low calcium leads to secondary hyperparathyroidism
- Increased parathyroid hormone leads to increased calcium reabsorption from bone and further issues with bone mineralisation
What is transient synovitis ?
-Temporary irritation and inflammation in the synovial membrane of the joint
What age group is transient synovitis most common in ?
3-10 years
How does transient synovitis present ?
- Usually occurs within a few weeks of a viral illness
- Limp
- Refusal to weight bear
- Groin or hip pain
- Mild low grade temperature
What is a serious differential in a child with joint pain and fever ?
-Septic arthritis
How is transient synovitis managed ?
- Simple analgesia
- Safety net to attend A&E if symptoms worsen or they develop a fever !
Define septic arthritis
-Infection inside a joint
when is septic arthritis most common ?
<4 yrs of age
How does septic arthritis usually present ?
- Single joint
- Rapid onset : hot red swollen painful joint
- Refusing to weight bear
- Stiffness and reduced range of motion
- Systemic Sx : fever, lethargy, sepsis
What is the most common bacterial cause of septic arthritis ?
-Staph aureus
What 4 other bacteria can cause septic arthritis ?
- Neisseria gonorrhoea (sexually active teenagers)
- Group A strep
- Haemophilus influenza
- E.coli
Give 4 other differential diagnosis for septic arthritis
- Transient synovitis
- Perthes
- Slipped upper femoral epiphysis
- JIA
How is septic arthritis managed ?
- Joint aspiration for gram staining, crystal microscopy, culture and Abx sensitivities.
- Empirical IV abx
- Sugical drainage and washout where necessary
What is perthes disease?
- Idiopathic, avascular necrosis of the femoral head due to disruption of blood flow
- Affecting the epiphysis of the femur