MSK: Hip Problems in Children Flashcards
What is developmental dysplasia of the hip (DDH)?
A congenital or acquired deformation of the hip joint.
This affects the development and stability of the acetabulum (hip socket) and proximal femur (thighbone)
This is a spectrum of disorders that includes mild dysplasia, subluxation, and dislocation of the hip.
When is DDH usually picked up?
Newborn exam.
Also at newborn baby check 6-8 weeks later.
Risk factors for DDH?
1) 1st degree FH
2) Born in breech presentation
3) Multiple pregnancy
4) Oligohydramnios
5) Incorrect swaddling techniques that restrict hip movement
How does oligohydramnios predipose to DDH?
Low levels of amniotic fluid can lead to increased intrauterine pressure, affecting hip development.
Clinical features of DDH?
1) Asymmetrical skin folds: uneven thigh or gluteal creases may indicate hip dysplasia or dislocation.
2) Leg length discrepancy
3) Limited hip abduction on one side
4) Significant bilateral restriction in abduction
5) Difference in the knee level when the hips are flexed
6) Clunking of the hips on special tests
What 2 special tests are used to check for DDH?
1) Ortolani test
2) Barlow test
Describe the Ortolani test
The baby is on their back with the hips and knees flexed.
Palms are placed on the baby’s knees with thumbs on the inner thigh and four fingers on the outer thigh.
Gentle pressure is used to abduct the hips and apply pressure behind the legs with the fingers to see if the hips will dislocate anteriorly
What is Barlow test?
Done with the baby on their back with the hips adducted and flexed at 90 degrees and knees bent at 90 degrees.
Gentle downward pressure is placed on knees through femur to see if the femoral head will dislocate posteriorly.
Clicking vs clunking in DDH exam?
Clicking - normal
Clunking - more likely to indicate DDH and requires an US
What is the investigation of choice in suspected DDH?
US of the hips
How can DDH present in older children and adolescents?
1) Gait abnormalities e.g. waddling gait, limping gait
2) Hip pain
3) Osteoarthritis (untreated cases)
Imaging investigation in children aged <4-6 months in DDH?
US
Imaging investigation in children aged >4-6 months in DDH?
Xrays
What is the goal of management of DDH?
To achieve and maintain a stable, concentric hip joint to facilitate normal development
In DDH, if the baby presents <6 months of age, what does 1st line treatment involve?
A Pavlik harness
What is a Pavlik harness?
A soft splint with the aim to hold the femoral head in the correct position to allow the hip socket (acetabulum) to develop a normal shape.
This harness keeps the baby’s hips flexed and abducted.
When is the Pavlik harness typically removed?
6-8 weeks later
Management of DDH if the harness fails or the diagnosis is made after 6 months of age?
Surgery
After surgery is performed, an hip spica cast is used to immobilises the hip for a prolonged period.
Name 6 hip problems in children
1) Development dysplasia of the hip
2) Transient synovitis (irritable hip)
3) Perthes disease
4) Slipped upper femoral epiphysis
5) Juvenile idiopathic arthritis (JIA)
6) Septic arthritis
How may hip pain present in children?
Hip pain will present differently depending on the developmental age of the child. They may present with:
- Limp
- Refusal to use the affected leg
- Refusal to weight bear
- Inability to walk
- Pain
- Swollen or tender joint
What are the 3 common causes of hip pain in 0-4 year olds?
1) septic arthritis
2) DDH
3) transient sinovitis
What are the 3 common causes of hip pain in 5-10 year olds?
1) Septic arthritis
2) Transient synovitis
3) Perthes disease
What are the 3 common causes of hip pain in 10-16 year olds?
1) septic arthritis
2) slipped upper femoral epiphysis (SUFE)
3) juvenile idiopathic arthritis (JIA)
What are some red flags for hip pain in children?
- Child under 3 years
- Fever
- Waking at night with pain –> malignancy
- Weight loss, anorexia, fever, night sweats & fatigue –> malignancy or infection
- Persistent pain
- Stiffness in the morning –> inflammatory joint disease
- Swollen or red joint –> infection or inflammatory joint disease
- Severe pain, agitation and anxiety –> evolving compartment syndrome
What are the 2 most common organisms causing septic arthritis in children?
1) Staph. aureus
2) Strep. pyogenes
Presentation of children with septic arthritis?
- fever
- joint pain
- swelling
- erythema & warmth
- limited range of movement
How is a diagnosis of septic arthritis made?
Joint aspiration & culture
What risk factors can predispose children to the development of septic arthritis?
1) Age: more prevalent among younger children, particularly those aged less than three years.
2) Pre-existing joint abnormalities e.g. DDH, JIA
3) Immunodeficiency
4) Recent joint trauma or surgery
5) Skin infections e.g. impetigo, cellulitis, abscesses
What age in children is septic arthritis most common?
<4 y/o
Mortality rate of septic arthritis in children?
Around 10%
Which organism can cause septic arthritis in sexually active teenagers?
Neisseria gonorrhoea (gonococcus)
What 3 joints does septic arthritis typically affect in children?
1) hip
2) knee
3) ankle
In some instances of septic arthritis, especially when the hip joint is involved, young children may present with pseudoparalysis.
What is this?
An apparent inability to move the affected limb secondary to pain rather than true paralysis.
What are 3 systemic manifestations of septic arthritis?
1) fever
2) malaise & irritability
3) lethargy
Mx of septic arthritis?
1) Aspirate joint prior to giving antibiotics where possible
2) Send the sample for gram staining, crystal microscopy, culture and antibiotic sensitivities
3) Start empirical IV antibiotics until the microbial sensitivities are known
4) Drainage of the affected joint if necessary
Complications of septic arthritis?
Osteomyelitis, sepsis, and joint destruction
What is transient synovitis also know as?
Irritable hip
What is irritable hip/transient synovitis?
A self-limiting inflammatory condition that affects the synovium within the hip joint.
It is caused by temporary (transient) irritation and inflammation in the synovial membrane of the joint (synovitis)
What is the most common cause of hip pain in children aged between 3-10 years old?
Transient synovitis
How is a diagnosis of transient synovitis made?
Diagnosis of exclusion - rule out serious pathologies e.g. septic arthritis.
What is transient synovitis typically preceded by?
A viral URTI
Do children with transient synovitis typically have a fever?
No - children with joint pain AND a fever need urgent management for septic arthritis.
What 3 factors is transient synovitis thought to be associated with?
1) Recent URTI
2) Recent bacterial infection, particularly a Streptococcal infection
3) Recent trauma to the hip joint
Clinical features of transient synovitis?
1) Hip pain
2) Limp
3) Low-grade temperature (30%)
4) Recent infection e.g. URTI or a bacterial infection - particularly Streptococcal
5) Recent trauma to the joint
6) Children should otherwise be systemically well
7) Onset of symptoms can be acute or gradual
8) Boys are more commonly affected
Describe hip pain in transient synovitis
This is most often unilateral however can present bilaterally.
The pain can radiate towards the groin and/or to the knee.
How may a limp present in children in transient synovitis?
This may be noticed by parents as the child refusing to weight-bear (seen in >60% of children with transient synovitis).
How will children with transient synovitis typically hold their 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.
Signs on examination in transient synovitis:
1) Typically they hold the leg in a flexed, abducted and externally rotated position
2) Tenderness on palpation of the hip joint
3) Limited internal rotation
4) Limp
5) Log roll test
What range of movement test is the most sensitive for transient synovitis?
Limited internal rotation
What special manoeuvre is indicated in transient synovitis?
Log roll test
What is the log roll test?
Ask 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 is a positive result on a log roll test in transient synovitis?
Involuntary muscle guarding when the leg is rolled passively.
When can a working diagnosis of transient synovitis can be managed in primary care?
- afebrile
- mobile but limping
- symptoms have been present for <48 hours
What 3 blood tests can be done to rule out other pathologies in transient synovitis?
1) FBC:
- WCC may be slightly raised in transient synovitis however is often normal
- A significantly raised WCC suggests underlying infection (think septic arthritis!)
2) CRP: may be slightly raised however a marked elevation in CRP should raise your suspicions of an underlying infection
3) ESR: typically normal in transient synovitis
What criteria can be used to help to distinguish between transient synovitis and septic arthritis in children presenting with hip pain?
Kocher criteria
What are the 4 aspects of the Kocher criteria?
1) Non-weight bearing
2) Temp >38.5
3) WCC >12,000 cells/mm3
4) ESR >40mm/hr
Explain the meaning of the results of the Kocher test
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
Xray results in transient synovitis?
Normal
3 xray results in septic arthritis?
1) joint effusion
2) narrowing of the joint space
3) destruction of the subchondral bone
It is worth noting that in the very early stages of septic arthritis x-rays may be normal.
What 2 imaging investigations may be indicated in transient synovitis?
1) XR
2) US
What may an US of the hip show in transient synovitis?
Intracapsular fluid, joint effusion and synovial thickening.
Note - these findings are also commonly seen in septic arthritis so an US of the hip may not be that helpful when trying to differentiate.
What is considered the gold standard investigation for diagnosing septic arthritis?
Arthrocentesis for synovial fluid analysis
Mx of transient synovitis?
Conservative:
- safetynet
- arrange a follow-up appointment after 48-hours to ensure symptoms are resolving
- arrange a subsequent follow-up 1-week from symptom onset to ensure that symptoms have fully resolved
Medical:
- Simple analgesia using paracetamol or ibuprofen
What is Perthes disease?
This involves disruption of the blood flow to the FEMORAL HEAD, causing avascular necrosis of the bone.
This affects the epiphysis of the femur (i.e. the bone distal to the growth plate (physis)).
What is Perthes disease also known as?
Legg-Calvé-Perthes disease
What age group does Perthes typically affect?
Primarily affects children aged 4-8.
Is Perthes’ more common in boys or girls?
Boys
Cause of Perthes disease?
Idio[athic
What is the main complication of Perthes?
Early hip osteoarthritis.
This is due to revascularisation or neovascularisation and healing of the femoral head over time.
There is remodelling of the bone as it heals –> causing a soft and deformed femoral head.
What 4 overlapping stages are seen in the pathophysiology of Perthes?
1) Necrosis
2) Fragmentation
3) Reossification
4) Remodelling
Describe necrosis stage of Perthes’
Avascular necrosis of the femoral head occurs due to compromised blood supply. This leads to bone cell death, marrow oedema, and subchondral microfractures.
Describe fragmentation stage of Perthes’
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.
Describe reossification stage of Perthes’
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.
Describe remodelling stage of Perthes’
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.
What staging system is used in Perthes’?
Catterall staging
Describe the Catterall staging system for Perthes
Stage 1: Clinical and histological features only
Stage 2: Sclerosis with or without cystic changes and preservation of the articular surface
Stage 3: Loss of structural integrity of the femoral head
Stage 4: Loss of acetabular integrity
Clinical features of Perthes?
1) Pain: localised to the hip, groin, or medial thigh
2) Limping
3) Limited range of motion
4) Leg length discrepancy
5) Muscle atrophy
6) Gait abnormalities
7) Delayed skeletal maturation
Will there be a history of trauma in Perthes?
No
If the pain is triggered by minor trauma, think about slipped upper femoral epiphysis, particularly in older children.
Describe pain in Perthes’ disease
- localised to the hip, groin, or medial thigh
- may be aggravated by activity and alleviated by rest
- pain may be referred to the knee (can lead to misdiagnosis)
What is the most common presenting symptom of Perthes?
Pain
What is the initial investigation of choice in Perthes disease?
Xray (however this can be normal)
What 4 investigations that can be helpful in establishing the diagnosis of Perthes?
1) xray
2) blood tests: typically normal, particularly inflammatory markers that are used to exclude other causes
3) Technetium bone scan
4) MRI scan
Xray findings in Perthes’?
Femoral head fragmentation, sclerosis, and flattening.
Management of Perthes’?
Based on the child’s age, disease severity, and stage.
1) Conservative management: bed rest, traction, crutches, analgesia, physiotherapy
2) Surgical management
Complications of Perthes?
Residual deformity
Leg length discrepancy
Osteoarthritis
What is slipped upper femoral epiphysis (SUFE) also known as?
Slipped capital femoral epiphysis (SCFE).
What is SUFE?
Where the head of the femur is displaced (‘slips’) along the growth plate.
Displacement of the femoral head epiphysis postero-inferiorly.
What is a key risk factor for SUFE?
Obesity
Is SUFE more common in boys or girls?
Boys
What is the typical exam presentation of SUFE?
An adolescent, obese male undergoing a growth spurt.
There may be a history of minor trauma that triggers the onset of symptoms.
Suspect SUFE if the pain is disproportionate to the severity of the trauma.
Presenting features of SUFE?
Can be vague:
- Hip, groin, thigh or knee pain
- Restricted range of hip movement
- Painful limp
- Restricted movement in the hip
- Loss of internal rotation of the leg in flexion
When examining the patient with SUFE, how will they prefer to keep their hip?
In external rotation.
What movement is particularly limited in SUFE?
Internal rotation.
What is the initial investigation of choice in SUFE?
Xray
Management of SUFE?
Surgery –> to return the femoral head to the correct position and fix it in place to prevent it slipping further.
What 3 ligaments make up the joint capsulse surrounding the hip joint?
1) Ileofemoral
2) Pubofemoral
3) Ischiofemoral
Role of the joint capsule?
1) Hold articulating bones together
2) Ensure joint stays stable when hip is moving
What 3 bones make up the acetabulum?
1) Ischium
2) Ileum
3) Pubis
What are 3 risk factors for developmental dysplasia of the hip?
1) Too much mechanical force in uterus e.g. in first borns (as uterus not stretched out)
2) Oligohydramnios
3) Breech position
