Orthopaedics: transient synovitis; Perthes Flashcards
Describe the difference in structure of adults and childrens bones [2]
Children have growth plates, whereas adults do not.
Children have more cancellous bone, which is the spongy, highly vascular bone in the centre of long bone. Adults have more cortical bone, which is the compact, hard bone around the outside
This makes children’s bones are more flexible but less strong.
Which types of fractures are children more likely to have compared to adults? [2]
Children are more likely to have a buckle fracture (or torus fracture), due to less strength against compression.
Children are more likely to have greenstick fractures, where only one side of the bone breaks whilst the other side of the bone stays intact.
Describe Salter-Harris Classification [5]
Use the SALTR mnemonic to remember the types:
Type 1: Straight across
Type 2: Above
Type 3: BeLow
Type 4: Through
Type 5: CRush
What is the overall principles of managing fractures in general [2]
The first principle is to achieve mechanical alignment of the fracture by:
* Closed reduction via manipulation of the joint
* Open reduction via surgery
The second principle is provide relative stability for a period of time, to allow healing. This can be done by fixing the bone in the correct position while it heals. There are various ways the bone can be fixed in position:
* External casts
* K wires
* Intramedullary wires
* Intramedullary nails
* Screws
* Plate and screws
Pain management in children is slightly different than adults. The World Health Organisation have a pain ladder for children that has only two steps:
What is it? [2]
Step 1: Paracetamol or ibuprofen
Step 2: Morphine
If a child requires morphine they generally need admission for a serious illness.
Which painkillers are not used in children? [3]
TOM TIP: Examiners like to test your knowledge on the pain medications that are not used in children. Codeine and tramadol are not used in children as there is unpredictability in their metabolism, so the effects vary too greatly to make them safe and effective options.
Aspirin is contraindicated in children under 16 due to the risk of Reye’s syndrome (except in certain circumstances such as Kawasaki disease).
TOM TIP: Examiners like to test your knowledge about the causes of hip pain in a child. It is worth being familiar with the differential diagnosis and distinguishing features of each cause.
What are they most likely to be depending on the age:
- 0-4 [3]
- 5-10 [3]
- 10-16 [3]
0 – 4 years:
* Septic arthritis
* Developmental dysplasia of the hip (DDH)
* Transient sinovitis
5 – 10 years:
* Septic arthritis
* Transient sinovitis
* Perthes disease
10 – 16 years:
* Septic arthritis
* Slipped upper femoral epiphysis (SUFE)
* Juvenile idiopathic arthritis
Describe what is meant by transient synovitis [1]
Transient synovitis, also known as ‘irritable hip’, is a self-limiting inflammatory condition that affects the synovium within the hip joint.
It is the most common cause of hip pain in children aged between 3-10 years old
What often preceds transient synovitis? [1]
It is often associated with a recent viral upper respiratory tract infection.
Describe the clinical features of transient synovitis [5]
Hip pain
* This is most often unilateral however can present bilaterally
* The pain can radiate towards the groin and/or to the knee
Limp
* This may be noticed by parents as the child refusing to weight-bear (seen in >60% of children with transient synovitis)
Refusal to weight bear
**Low-grade temperature **(seen in 30% of children with transient synovitis)
Recent infection e.g. upper respiratory infection or a bacterial infection - particularly Streptococcal
It is important to note that children should otherwise be systemically well
What are the examination findings in transient synovitis [4]
The following signs are typical of transient synovitis:
Look
* Children will typically hold the leg in a flexed, abducted and externally rotated position - this position results in the least amount of intracapsular pressure within the joint and is therefore the least painful
Feel
* Tenderness on palpation of the hip joint
Move
* Limited internal rotation - this is the most sensitive range of movement test for transient synovitis
* Limp when asked to walk
Special manoeuvres- Log roll test
- The log roll test is carried out by asking the patient to lay supine with the hip and knee extended
* The examiner then passively rotates the entire limb internally and then externally
* A positive test is defined as involuntary muscle guarding when the leg is rolled passively
What are red flag symptoms for child presenting with a limp and what would they indicate? [6]
Pain waking the child at night
* Suggests a malignancy
Weight loss, anorexia, fever, night sweats and fatigue
* Suggests a malignancy or infection
Redness, swelling and stiffness of the joint
* Suggests infection or inflammatory joint disease
Limp that is worse in the morning
* Suggests inflammatory joint disease
Unexplained rash or bruising
* Suggests inflammatory joint disease or child maltreatment
Severe pain, agitation and anxiety
* Suggests evolving compartment syndrome
Which criteria can be used to distinguish between transient synovitis and septic arthritis? [+]
The Kocher criteria can be used to help to distinguish between transient synovitis and septic arthritis in children presenting with hip pain. The criteria and explanation of the results are explained below.
Criteria
1. Non-weight bearing
2. Temperature >38.5°
3. White cell count >12,000 cells/mm3
4. ESR >40mm/hr
Explanation of the results
0 criteria met = very low risk of septic arthritis
1 criterion met = 3% probability of septic arthritis
2 criteria met = 40% probability of septic arthritis
3 criteria met = 93% probability of septic arthritis
4 criteria met = 99% probability of septic arthritis
A patient has ?transient synovitis.
NICE recommends that an x-ray of the hip should be carried out on the same day if which any of the following are present [5]
There are no indications for an urgent assessment which include any red flag symptoms, the child is < 3 years old, the child is >9 years old with painful or restricted hip movements, there is an inability to weight-bear or there is suspicion of child maltreatment
How does transient synovitis present on xray? [1]
How does US of the hip present? [3]
Xray: normal
Ultrasound findings in transient synovitis can include intracapsular fluid, joint effusion and synovial thickening
NICE recommend that a child aged between 3-9 years with a working diagnosis of transient synovitis can be managed in primary care if: [3]
They are afebrile, mobile but limping and symptoms have been present for < 48 hours
Describe the management of transient synovitis [3]
Conservative
* It is important to explain to parents the natural history of the condition and to provide adequate safety netting
* For example - we would expect the symptoms to resolve within 1 week with rest and simple pain relief. We would not expect the symptoms to worsen or the child to become systemically unwell (fever, lethargy, irritability). If this does happen then you should take the child to the emergency department immediately as this could be a sign of a more serious pathology.
* Arrange a follow-up appointment after 48-hours to ensure symptoms are resolving
Medical
- Simple analgesia using paracetamol or ibuprofen
Typically there is a significant improvement in symptoms after 24 – 48 hours. Symptoms fully resolve within 1 – 2 weeks without any lasting problems. Transient synovitis may recur in around 20% of patients.
What is the cause of Perthes? [1]
Perthes’ disease, or Legg-Calve-Perthes, is a childhood orthopaedic condition characterized by idiopathic avascular necrosis of the femoral head.
Perthes disease progresses through four overlapping stages.
What are they? [4]
Necrosis:
- Avascular necrosis of the femoral head occurs due to compromised blood supply. This leads to bone cell death, marrow oedema, and subchondral microfractures.
- Radiographically, this stage may appear normal or show early signs of femoral head involvement.
Fragmentation:
- As necrotic bone is resorbed, the femoral head begins to fragment and collapse. Osteoclasts remove dead bone, while the reparative process involving osteoblasts and new blood vessels commences.
- Radiographs reveal fragmentation and decreased density of the femoral head.
Reossification:
- New bone formation occurs, and the femoral head starts to regain its original shape.
- Radiographically, there is increased density and restoration of the femoral head contour.
Remodeling:
- The femoral head continues to remodel and reshape to its final form. Normal joint function may be restored depending on the congruence achieved between the femoral head and acetabulum.
- Long-term complications include early degenerative changes, hip dysplasia, or femoroacetabular impingement.
Catterall staging is used for Perthes disease.
What are the 4 different stages? [4]
Which age group is Perthes in? [1]
It occurs in children aged 4 – 12 years, mostly between 5 – 8 years, and is more common in boys.
Describe the presentation of Perthes [4]
Perthes disease present with a slow onset of:
* Pain in the hip or groin
* 5-8 years old
* Limp
* Restricted hip movements
* There may be referred pain to the knee
There will be NO history of trauma. If the pain is triggered by minor trauma, think about slipped upper femoral epiphysis, particularly in older children.
Describe the Ix for Perthes [3]
Radiography: Plain radiographs of the pelvis, including anteroposterior and frog-leg lateral views, are the initial imaging modality. Findings include femoral head fragmentation, sclerosis, and flattening.
Magnetic resonance imaging (MRI): MRI can detect early stages of Perthes disease and assess the extent of avascular necrosis, joint effusion, and marrow oedema.
Bone scintigraphy: This can identify early-stage disease and provide information about the extent of involvement, but is less commonly used due to radiation exposur
Describe the management of Perthes disease (conservative [4] and surgical [3]
Conservative management:
- This includes activity modification
- Pain management with analgesics or anti-inflammatory medications
- physical therapy to maintain range of motion and muscle strength.
- Orthotic devices, such as casts or braces, may be used to provide containment of the femoral head within the acetabulum.
Surgical management:
* Procedures include femoral or pelvic osteotomies to improve hip joint congruence
* arthrodiastasis to decompress the hip joint
* in severe cases, hip arthroplasty.
What would indicate surgical management for Perthes? [3]
Indications for surgery include persistent pain, progressive deformity, or failed conservative management.
